BRAKE CYLINDER COMPRISING TWO INTEGRATED CHAMBERS
20220332297 · 2022-10-20
Assignee
Inventors
Cpc classification
B60T11/18
PERFORMING OPERATIONS; TRANSPORTING
B60T8/409
PERFORMING OPERATIONS; TRANSPORTING
G05G1/46
PHYSICS
B60T7/042
PERFORMING OPERATIONS; TRANSPORTING
International classification
B60T8/40
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A brake cylinder for use with an automotive simulator includes a brake cylinder housing having a master chamber, a slave chamber, a wall disposed therebetween and at least one channel configured to provide fluid communication between the master chamber and the slave chamber. In some variants, the at least one channel may be an opening configured to provide fluid communication between the master chamber and the slave chamber, in another variant the channel may be an external channel such as a tube. The brake cylinder also includes a master piston configured to pressurize fluid in the master chamber when a brake pedal is pressed. The brake cylinder further includes a slave piston and a pressure sensor disposed in fluid communication with the brake cylinder. The pressure sensor is configured to measure pressure in the chambers and send a signal to a processor indicative of movement of the brake pedal. When pressurizing fluid in the master chamber, the master piston is configured to drive fluid from the master chamber to the slave chamber via the at least one channel to increase pressure in the slave chamber.
Claims
1. A brake cylinder for an automotive simulation system, comprising: a brake cylinder housing comprising (i) a master cylinder chamber, (ii) a slave cylinder chamber, (iii) a wall disposed between the master cylinder chamber and the slave cylinder chamber, (iv) at least one channel to provide fluid communication between the master cylinder chamber and the slave cylinder chamber, wherein the brake cylinder is configured to connect to a brake pedal; a master piston at least partially disposed within the master cylinder chamber, the master piston configured to pressurize fluid in the master cylinder chamber when the brake pedal is depressed; a slave piston at least partially disposed within the slave cylinder chamber; and at least one pressure sensor disposed in fluid communication with the brake cylinder, wherein the at least one pressure sensor (1) measures pressure inside the master cylinder and slave cylinder chambers and (2) sends a signal to a processor connected to said automotive simulation system indicating movement of the brake pedal, wherein the master piston is configured to drive pressurized fluid from the master cylinder chamber to the slave cylinder chamber via the at least one channel to increase pressure in the slave cylinder chamber.
2. The brake cylinder according to claim 1, wherein the at least one channel to provide fluid communication between the master cylinder chamber and the slave cylinder chamber comprises an opening integrated into the wall.
3. The brake cylinder according to claim 1, wherein the master piston is configured to move along an axis of the master piston between a first master position and a second master position, and the slave piston is configured to move along an axis of the slave piston between a first slave position and a second slave position, wherein the axis of movement of the master piston and the axis of movement of the slave piston are parallel to each other.
3. The brake cylinder according to claim 3, wherein the master piston is configured such that movement of the master piston from the first master position to the second master position is in a first direction and drives movement of the slave piston from the first slave position to the second slave position in a second direction that is opposite from the first direction, and movement of the master piston from the second master position to the first master position is in the second direction and drives movement of the slave piston from the second slave position to the first slave position in the first direction.
4. The brake cylinder according to claim 3, further comprising: a damper housing positioned coaxially adjacent to the slave cylinder chamber, the slave piston at least partially disposed within the damper housing; and a damper disposed within the damper housing, wherein the slave piston is configured such that movement of the slave piston from the first slave position to the second slave position compresses the damper and movement of the slave piston from the second slave position to the first slave position decompresses the damper.
5. The brake cylinder according to claim 3, further comprising: a master spring connected to the master piston, the master spring configured to bias the master piston towards the first master position in the second direction; and a slave spring connected to the slave piston, the slave spring configured to bias the slave piston towards the first slave position in the first direction.
6. The brake cylinder according to claim 5, wherein the slave piston includes a block attached thereto that is configured to limit movement of the slave piston in the second direction via contact with the damper housing.
7. The brake cylinder of claim 6, wherein the slave piston further comprises a threaded nut configured to adjust a stiffness response of the brake pedal, and wherein the slave piston further comprises a configuration in which the block is disposed between the damper housing and the threaded nut.
8. The brake cylinder according to claim 1, wherein the master piston comprises: a master rod at least partially disposed within the master cylinder chamber; a brake pedal connector configured to attach to the brake pedal; and a brake arm adjuster configured to adjust a distance between the brake pedal connector and the master rod.
9. The brake cylinder according to claim 1, wherein the at least one pressure sensor is configured such that pressure measurements of the at least one pressure sensor are directly proportional to depression displacement of the brake pedal.
10. The brake cylinder according to claim 1, wherein the brake cylinder housing includes an attachment opening configured to attach the brake cylinder to a base.
12. The brake cylinder according to claim 1, wherein the at least one channel to provide fluid communication between the master cylinder chamber and the slave cylinder chamber comprises an external channel or tube that is not integrated into the wall.
13. The brake cylinder according to claim 1, wherein the brake cylinder is configured to pivotally connect to a brake pedal.
14. A brake system for an automotive simulation system, the brake system comprising: a base; a brake pedal connected to the base; and a brake cylinder connected to the brake pedal, the brake cylinder comprising: a brake cylinder housing comprising (i) a master cylinder chamber, (ii) a slave cylinder chamber, (iii) a wall disposed between the master cylinder chamber and the slave cylinder chamber, and (iv) at least a channel configured to provide fluid communication between the master cylinder chamber and the slave cylinder chamber; a master piston at least partially disposed within the master cylinder chamber, the master piston configured to pressurize fluid in the master cylinder chamber when the brake pedal is depressed; a slave piston at least partially disposed within the slave cylinder chamber; and at least one pressure sensor disposed within the brake cylinder housing, wherein the at least one pressure sensor (1) measures pressure inside the master cylinder and slave cylinder chambers and (2) sends a signal to a processor connected to said automotive simulation system indicating movement of the brake pedal, wherein the master piston is configured to drive pressurized fluid from the master cylinder chamber to the slave cylinder chamber via the at least one channel to increase pressure in the slave cylinder chamber.
15. The brake system according to claim 14, wherein the at least one channel to provide fluid communication between the master cylinder chamber and the slave cylinder chamber comprises an opening integrated into the wall.
16. The brake system according to claim 14, wherein the master piston is configured to move along an axis of the master piston between a first master position and a second master position, and the slave piston is configured to move along an axis of the slave piston between a first slave position and a second slave position, wherein the axis of movement of the master piston and the axis of movement of the slave piston are parallel to each other.
17. The brake system according to claim 16, wherein the master piston is so configured that movement of the master piston from the first master position to the second master position is in a first direction and drives movement of the slave piston from the first slave position to the second slave position in a second direction that is opposite of the first direction, and movement of the master piston from the second master position to the first master position is in the second direction and drives movement of the slave piston from the second slave position to the first slave position in the first direction such that the slave piston is pushed in an opposite direction of the master piston when the master piston is pushed.
18. A brake system according to claim 17, wherein the brake cylinder further comprises: a damper housing positioned coaxially adjacent to the slave cylinder chamber, the slave piston at least partially disposed within the damper housing; and a damper disposed within the damper housing, wherein the slave piston is so configured that movement of the slave piston from the first slave position to the second slave position compresses the damper and movement of the slave piston from the second slave position to the first slave position decompresses the damper.
19. A brake system according to claim 17, further comprising: a master spring connected to the master piston, the master spring configured to bias the master piston towards the first master position in the second direction; and a slave spring connected to the slave piston, the slave spring configured to bias the slave piston towards the first slave position in the first direction.
20. A brake system according to claim 19, wherein the slave piston includes a block attached thereto that is configured to limit movement of the slave piston in the second direction via contact with the damper housing.
21. A brake system according to claim 20, wherein the slave piston further comprises a threaded nut configured to adjust a stiffness response of the brake pedal, and wherein the slave piston further comprises a configuration in which the block is disposed between the damper housing and the threaded nut.
22. A brake system according to claim 14, wherein the master piston comprises: a master rod at least partially disposed within the master cylinder chamber; a brake pedal connector configured to pivotably connect to the brake pedal; and a brake arm adjuster configured to adjust a distance between the brake pedal connector and the master rod.
23. A brake system according to claim 14, wherein the at least one pressure sensor is configured such that pressure measurements of the pressurized fluid by at least one pressure sensor are a function of the depression displacement of the brake pedal.
24. A brake system according to claim 14, wherein the brake cylinder housing includes an attachment opening configured to pivotably attach the brake cylinder to the base.
25. The brake system according to claim 14, wherein the at least one channel to provide fluid communication between the master cylinder chamber and the slave cylinder chamber comprises an external channel or tube that is not integrated into the wall.
26. The brake system according to claim 14, wherein the brake pedal is pivotally connected to the base.
27. The brake system according to claim 14, wherein the brake cylinder is pivotally connected to a brake pedal.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate various embodiments and aspects of the present disclosure. In the drawings:
[0041]
[0042]
[0043]
[0044]
[0045]
[0046]
[0047] and
[0048]
[0049]
DETAILED DESCRIPTION
[0050] The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and in the following description to refer to the same or similar parts. While several exemplary embodiments and features of the disclosure are described herein, modifications, adaptations, and other implementations are possible without departing from the spirit and scope of the disclosure. For example, substitutions, additions, or modifications may be made to the components illustrated in the drawings, and the exemplary methods described herein may be modified by substituting, reordering, or adding steps to the disclosed methods. Accordingly, the following detailed description does not limit the disclosure. Instead, the proper scope of the disclosure is defined by the appended claims.
[0051] Systems and devices consistent with the present disclosure generally relate to a brake cylinder. More particularly, systems and devices consistent with the disclosure relate to a brake cylinder for use in automotive simulators that is both cost effective to produce and provides authentic feedback when in use.
[0052]
[0053] The brake system is configured to communicate with a computer system running car simulation software. Communication between the brake system and the computer system could be via wires such as USB or via wireless communication such as Bluetooth. The communication between the brake system and the computer system is typically in real-time to ensure that any actions on the brake pedal are immediately communicated to the car simulation software to minimize lag time and provide a realistic feel for the user using the simulation software. When pressing the brake pedal 101, a master cylinder piston 107 is pushed into the brake cylinder 201 and the brake pressure is then measured and communicated back to the computer system via the sensor 109. The sensor 109 is able to detect when, how much, and how fast pressure on the brake pedal is changed. The brake cylinder 201 is connected to the brake pedal 101 by a rod clevis 207 at the end of the piston rod 205 of the master cylinder piston 107 which grips around a mount plate 113 on the arm of the brake pedal 101.
[0054] A “rod clevis” 207 is a specific example embodiment of a “brake cylinder connector”, and the two terms will be used interchangeably and uses the same reference number 207.
[0055]
[0056] As seen in
[0057] It is the pressure increase in internal pressure caused by the depression of the pedal 101 which may be detected by a pressure sensor 204.
[0058] As seen in
[0059] As seen in
[0060] When the master cylinder piston element 213 is pressed towards the fluid inside the master cylinder chamber 215 (such as in the situation depicted in
[0061] The piston seal 242, 244 for each of the master cylinder piston element 213 and the slave cylinder piston element 223 may be a u gasket. When fluid is being pressed, the lips of the u gaskets 242, 244 are pressed towards the inner walls of the cylinder chambers 215, 221. As can be seen, the u gasket 244 of the slave piston element 223 is mounted opposite the u gasket 242 of the master piston element 213, since in the master cylinder chamber 215 the fluid is in front of the piston element 213, whereas in the slave cylinder chamber 221 fluid is between the slave piston element 223 and the slave rod guide 231. Due to the u gaskets' 242, 244 seal, air is present in the master chamber 215 behind the master cylinder piston 107 and in front of the slave cylinder piston 223. In the slave chamber 221, a hole should be present at the end to ensure air is allowed to leave and enter the chamber 221 as the slave piston 223 moves back and forth.
[0062] The end of the slave piston rod 230 distal to the master cylinder piston 107 is connected to an end bolt 226 and a block element 225 via windings at the end of the slave cylinder rod 230. When the slave cylinder piston 223 is pushed by the fluid entering the slave cylinder chamber 221, the block element 225 is dragged towards and into a brake cylinder damper housing 227 and moves with the piston 223 back and forth based on pressure provided by the fluid entering the slave cylinder chamber 221. Inside the damper housing 227, a dampener 229 is positioned between the block element 225 and an inner wall of the housing 227. The dampener 229 is made from flexible, elastic material (e.g., rubber, silicone, etc.), where the flexibility of the elastic material influences the perceived softness of the pedal 101 in use. For example, a dampener 229 with greater flexibility will result in the pedal 101 being perceived as softer than when a stiffer dampener 229 with less flexibility is used. Additionally, a threaded nut may be included on the slave piston 223 next to the block element 225 on the opposite side of the dampener 229. Manipulation of the threaded nut may be used to adjust the stiffness of the brake pedal 101. The block element 225 has an edge limiting how far the block element can move into the damper house and thereby how far the brake pedal can be pressed.
[0063] By the optional threaded nut being placed next to the block element 225 on the opposite side of the dampener 229 is understood that the block element 225 is arranged between the threaded nut 226 and the dampener 229. This threaded nut 226 is also called the end bolt 226. The arrangement of the end bolt 226 affects the default position of the block element 225 as screwing the bolt further onto the windings of the slave cylinder rod 230 such that the end bolt 226 is closer to the dampener 229 forces the end block 225 placed between the end bolt 226 and the dampener 229 towards the dampener 229. By changing the distance between the block element 225 and the damper housing, the travel range of the pedal in the first phase of the braking process is adjusted. The travel range is how far the pedal can be pressed before the mechanical stop 260 between the extending edge of the block element 225 and the damper housing 227 is engaged such that the further movement of the block element 225 is hindered whereafter the second phase of the braking process begins. During the movement of the block element 225 the dampener 229 is being deformed and the user needs to apply force to the brake pedal 101 to cause this deformation, this will give the user a feeling of resistance in the pedal. Once the edge of the block element is in contact with the damper housing 227 the resistance is no longer caused by the deformation of the dampener 229, but will be the hydraulic pressure related to compression of the fluid in the brake cylinder 201. Hence, the arrangement which allows the block element 225 to travel a distance before contacting the damper housing 227 gives the user a more realistic brake feel with two stages having significantly different resistance, i.e. requiring significantly different force to be applied by the user to the pedal. In the second phase the user will not feel the pedal move even as the pressure rises and detects increased braking force.
[0064] In the slave cylinder chamber 221, a slave rod guide 231 is mounted inside the housing 203 for guiding the rod of the slave piston 223 and allowing movement of the piston 223 in only the axial direction. The slave cylinder piston 223 can move back and forth inside the slave cylinder chamber 221 where the fluid (e.g., oil or other liquid) is present.
[0065] A slave cylinder spring 233 is also present that, when compressed, applies pressure between an inner wall of the chamber 221 and the piston 223 ensuring that the slave cylinder piston 223 moves back to a position associated with the released orientation when pressure on the pedal 101 has been released. The slave cylinder spring 233 is mounted on the internal slave cylinder rod guide 234 to keep the slave cylinder spring 233 in place.
[0066] As seen in
[0067] In other embodiments, the pressure sensor 204 may be arranged to be in fluid connection with either the slave cylinder chamber 221 or the master cylinder chamber 215 at any position along the cylinder housing 203. In yet other embodiments the pressure sensor 204 mare be arranged spaced away from the cylinder housing 203 while still being in fluid connection with either the master cylinder chamber 215 or the slave cylinder chamber 221, e.g. by connection with a tube.
[0068]
[0069]
[0070] As seen in
[0071]
[0072]
[0073] In other embodiments as illustrated in
[0074]
[0075] The embodiment illustrated in
[0076] In some embodiments the slave cylinder piston element 223 is similarly connected to the slave cylinder rod 230 by the second end of the slave cylinder rod 230″ extending into a hollow of the slave cylinder piston element 223. In some variants the slave cylinder rod 230 will further be connected to the slave cylinder piston by a winding or by other known means of connection.
[0077] In an embodiment as illustrated in
[0078] In alternative embodiments wherein there is no master cylinder stop member, the first end of the master cylinder spring 217 is arranged to contact the end wall at the first end of the master cylinder chamber 217′. In such cases the first end of the master cylinder spring 217′ may be mounted in or otherwise connected to the end wall at the first end of the master cylinder chamber 217′.
[0079] In some embodiments the slave cylinder spring 233 may similarly be mounted between the slave cylinder piston element 223 and the end wall at the second end of the slave cylinder chamber 221″ or a slave cylinder stop element 245 mounted at said end wall. In an embodiment the slave cylinder spring 233 is mounted such that the first end of the slave cylinder spring 233′ is guided by the slave cylinder piston element 223, e.g. by at least part of the first end of the slave cylinder spring 233′ encircling at least part of the slave cylinder piston element 223. In an embodiment the second end of the slave cylinder spring element 221″ is guided by a slave cylinder stop element 245, e.g. by at least a part of the second end of the slave cylinder spring element 221″ being arranged to encircle at least a part of the slave cylinder stop element 245. In an alternative embodiment where there is no slave cylinder stop element 245 comprised in the slave cylinder chamber 221 the second end of the slave cylinder chamber spring 233″ is mounted in or otherwise connected to the end wall at the second end of the slave cylinder chamber 221″.
[0080] Same as for the previously described embodiments the brake cylinder 201 of
[0081] As the effects of the components remain the same and interact in the same manner, in the various embodiment the skilled person would understand that it is possible to use these elements in combination without changing the essence of the invention and should not be construed as limited to the particular combinations shown in the illustrations. For example the spring arrangement illustrated in the embodiment of
[0082] In the embodiments illustrated in
[0083]
[0084]
[0085]
[0086] As seen in
[0087] A master cylinder rod guide 211 is arranged for guiding a master cylinder rod 205 of the master cylinder piston and allowing movement of the rod 205 only in an axial direction. In some variants the master cylinder rod guide 211 may be mounted inside the master cylinder chamber 215 in some other variants the master cylinder rod guide 211 may be mounted adjacent to and/or abutting the master cylinder chamber. The first end of the master cylinder rod 205′ is disposed within the master cylinder chamber 215 and contacts a piston element 213, the piston element 213 being equipped with a seal 242. In some variants the master cylinder rod 205 may be connected to the piston element 213, for example by means of threading allowing the piston element 213 to be releasably connected with the master cylinder rod 205 by screwing the piston element 213 onto the master cylinder rod 205. In other variants the master cylinder rod 205 may be abutting the piston element 213 and being arranged such that they may be in contact. The piston element 213 is adapted to move back and forth inside the master cylinder chamber 215 along the direction of the longitudinal axis of the master cylinder chamber 215. The master cylinder rod 205 is arranged such that the movement of the master cylinder rod affects the movement of the piston element 213. A stop member 240 may be located at the first end of the master cylinder chamber 215′, i.e. the end of the master cylinder chamber 215 opposite the end at which the master cylinder rod 205 enters the master cylinder chamber 215 which in turn is the second end of the master cylinder chamber 215″. The movement of the master cylinder piston element 213 is limited by the rod guide 211 and either the stop member 240 or the first end of the master cylinder chamber 215′. The rod guide 211 limits the movement of the master cylinder rod 205 to be along the axis of the master cylinder chamber 215. In embodiments having the stop member 240, it limits how far the master cylinder piston element 213 can travel inside the master cylinder chamber 215. In a variant the stop element 240 is adapted to ensure that the master cylinder piston element cannot move past the one or more openings 219 such that fluid from the slave cylinder chamber 221 cannot enter the master cylinder chamber 215 behind the master cylinder piston element 213. This is achieved by the length of the stop member 240 being such that it ensures that the master cylinder piston element 213 cannot be extended past the opening 219 between the master and the slave chambers 215, 211. In embodiments having no stop member 240, the distance which the master cylinder piston element 213 can travel is limited by the first end of the master cylinder chamber 215′ and the dimensions of the piston element 213 itself, in particular the length of the piston element 213. In other variants of such embodiments with no stop member 240, the placement of the one or more openings 219 and the length of the piston element 213 are such that the entirety of the master cylinder piston element 213 cannot be extended past the opening 219 between the master and the slave chambers 215, 211 such that fluid cannot enter the space between the second end of the master cylinder chamber 215″ and the master cylinder piston element 213.
[0088] A master cylinder spring 217 is arranged within the master cylinder chamber 215. A first end of the master cylinder spring 217′ is disposed at the first end of the master cylinder chamber 215′. In some embodiments having a stopper member 240 arranged at the first end of the master cylinder chamber 215′ the first end of the master cylinder spring 217′ may be arranged within a hollow opening of the stop member 240. In other variants the embodiment having a stopper member 240 arranged at the first end of the master cylinder chamber 215′ the first end of the master cylinder spring 217′ may be arranged such that the first end of the master cylinder spring 217′ encircles the master cylinder stopper member 240. In other embodiments wherein the master cylinder chamber 215 comprises no stopper member the first end of the master cylinder spring 217′ is at least partially arranged within a cavity in the end wall of the first end of the master cylinder chamber 215′. In another variant the first end of the master cylinder spring 217′ is arranged to abut the end wall at the first end of the master cylinder chamber 215′.
[0089] In some embodiments the second end of the master cylinder spring 217″ opposite of the first end of the master cylinder spring 217′ is disposed within a hollow opening of the master cylinder rod 205 such that at least part of the master cylinder spring 217 extends through the body of the master cylinder piston element 213.
[0090] In alternative embodiments the master cylinder rod 205 is solid and the second end of the master cylinder spring 217″ is guided by the piston element 213. In such embodiments the second end of the master cylinder spring 217″ may be arranged within a hollow section of the master cylinder piston element 213 such that at least part of the master cylinder spring 217 is encircled by part of the master cylinder piston element 213. In such a configuration the second end of the master cylinder spring 217″ may abut the first end of the master cylinder rod 205′ if a central channel extends throughout the body of the piston element 213, such a channel may for example be equipped with internal threading for connecting the piston element 213 to the master cylinder rod 205. In alternative variants of such embodiments the second end of the master cylinder spring 217″ may be disposed to surround part of the master cylinder piston element 213. In these configuration the master cylinder piston element 213 guides the second end of the master cylinder spring 217″ by restricting its movement in the radial direction within the master cylinder chamber 215, that is in any other direction than the axial direction of the master cylinder chamber 215.
[0091] When force is applied to the master cylinder rod 205, i.e. when a user applies pressure to the pedal, such that the master cylinder rod 205 moves further into the master cylinder chamber 215, i.e. in the direction from the second end of the master cylinder chamber 215″ towards the first end of the master cylinder chamber 215′, the master cylinder spring 217 is compressed. The forces of the compressed master cylinder spring 217 applies force to the points of contact at the first 217′ and second end of the master cylinder spring 217″. At the first end of the master cylinder spring 217′ pressure is applied to the contact point at the end of the master cylinder chamber 215′, i.e. the stop member 240 or the end wall at the first end of the master cylinder chamber 215′. At the second end of the master cylinder spring 217″ pressure is applied to the contact point at the master cylinder rod 205 and/or the master cylinder piston element 213 such that the spring force is applied to the master cylinder rod 205 either directly or transmitted to the master cylinder rod 205 via the master cylinder piston element 213.
[0092] The force from the master cylinder spring 217 acts upon the master cylinder rod 205 to move it back to a position associated with a default position of the master cylinder rod 205 associated with no pressure being applied by a user to the pedal 101. In other words, by the default position is understood the unloaded position of the brake and brake cylinder.
[0093] In some embodiment the master cylinder spring 217 may be mounted around an internal master cylinder rod guide 218 to keep the master cylinder spring 217 arranged as intended. In other embodiments the master cylinder spring 217 will be guided to stay in the intended position by the master cylinder piston element 213 and/or the master cylinder stop member 240 and/or a cavity in the end wall of the first end of the master cylinder chamber 217′.
[0094] Similar to the configuration in the master cylinder chamber 215, the slave cylinder chamber 221 comprises a slave cylinder rod guide 231 mounted inside the slave cylinder chamber 221 for guiding a slave cylinder rod 230 and allowing movement of the slave cylinder rod 230 only in an axial direction substantially parallel to the axis of movement of the master cylinder rod 205. At least part of the slave cylinder rod 230 is disposed within the slave cylinder chamber 221. The slave cylinder rod 230 is arranged such that the first end of the slave cylinder rod 230′ contacts a slave cylinder piston element 223. In some embodiments the slave cylinder rod 230 may comprise an integrated slave cylinder piston element 223 at the first end of the slave cylinder rod 230′. In other embodiments the first end of the slave cylinder rod 230′ may be releasably connected to the slave cylinder piston element 223 for example by both components comprising threading such that they may be releasably connected by screwing the slave cylinder piston element 223 onto the first end of the slave cylinder rod 230′. In yet other alternative embodiments the slave cylinder rod 230 is arranged such that the first end of the slave cylinder rod 230′ abuts and is in contact with the slave cylinder piston element 223. The slave cylinder piston element 223 has a slave cylinder seal 244 arranged around the body of the slave cylinder piston element 223 to create a fluid tight seal between the volumes of the slave cylinder chamber separated by the cylinder piston element 223. The slave cylinder piston element 223 is adapted to move back and forth inside the slave cylinder chamber 221 along the direction of the longitudinal axis of the slave cylinder chamber 221. A slave cylinder stop member 245 may be located at the closed first end of the slave cylinder chamber 221′. Alternatively the slave cylinder piston may stop against the end wall of the first end of the slave cylinder chamber 221′. The movement of the slave cylinder piston element 223 within the slave cylinder chamber 221 along the axis of the slave cylinder chamber 221 is at the second end of the slave cylinder chamber 221″ limited by the rod guide 231 and at the first end of the slave cylinder chamber 221′ it is limited either by the slave cylinder stop member 245 or alternatively by the end of the slave cylinder chamber. The slave cylinder rod guide 231 optionally in combination with slave cylinder spring 233 limits the movement of the slave cylinder rod 230 to be along the axis of the slave cylinder chamber 221.
[0095] In other embodiments the slave cylinder piston element 223 is arranged such that it cannot translate past the one or more openings 219 such that fluid from the master cylinder chamber 215 cannot enter the slave cylinder chamber 221 behind the slave cylinder piston element 223, i.e. on the side of the slave cylinder piston element 223 closest to the second end of the slave cylinder chamber 221″. In embodiment comprising a slave cylinder stop element 245, this is achieved by the length of the slave cylinder stop member 245 and the dimensions of the slave cylinder piston element 223 being such that it ensures that the slave cylinder piston element 223 cannot be extended past the opening 219 between the master and the slave chambers 215, 211. In embodiments where the travel range of the slave cylinder piston element 223 is limited by the end wall at the first end of the slave cylinder chamber 221′, it is achieved by the dimensions, in particular the length of the slave cylinder piston element 223 along the axis of the slave cylinder chamber, being adapted to cover all one or more holes 219 when the slave cylinder piston element 223 contacts the end wall at the first end of the slave cylinder chamber 221′.
[0096] In some variants of embodiments having both a master and a slave stop members 240, 245, the dimensions of the master and the slave stop members 240, 245 as well as the dimensions of the master and the slave piston element 213, 223 are the same. In other variants the dimensions of the components of the master cylinder chamber 215 and the slave cylinder chamber 221 may however vary. In yet other variants a stop member 240, 245 may be present in either the master cylinder chamber 215 or the slave cylinder chamber 221 while there is no stop member 240, 245 in the other chamber 215, 221.
[0097] A slave cylinder spring 233 is arranged within the slave cylinder chamber 221 such that the spring forces of the slave cylinder spring 233 acts upon the slave cylinder piston element 223 to bring it back to a default position corresponding to no pressure being applied by the user. In an embodiment the first end of the slave cylinder spring 233′ is arranged to contact the end of the slave cylinder piston element 223 facing the second end of the slave cylinder chamber 221′ and the second end of the slave cylinder spring 233 opposite of the first end is disposed at the slave cylinder rod guide 231.
[0098] When force is applied to the slave cylinder rod 230 such that the slave cylinder rod 230 translates in the direction from the first end of the slave cylinder chamber 221′ towards the second end of the slave cylinder chamber 221, i.e. by a user applying pressure to the pedal, the slave cylinder spring 230 is compressed. The forces of the compressed slave cylinder spring 233 applies force to the slave cylinder piston element 223 and the slave cylinder rod guide 231 such that the slave cylinder rod 230 moves back to a default position of the slave cylinder rod 230 associated with no pressure being applied by a user to the pedal 101. In an embodiment the slave cylinder spring 230 is mounted around an internal slave cylinder rod to keep the slave cylinder spring 233 in place.
[0099] The second end of the slave cylinder rod 230″, i.e. the end opposite the end arranged to contact the slave cylinder piston element 223, is arranged in contact with a damper piston 250. In some variants the damper piston 250 may be connected to the slave cylinder rod 230, e.g. they may be comprised of a single piece of material or they may be assembled from two component that are fixed together or releasably connected. In other variants the slave cylinder rod 230 may simply be arranged to be capable of physically contacting the damper piston 250 without the two components being connected such that force may be transferred from the slave cylinder rod to the damper piston 250.
[0100] A slave cylinder cap 224 is mounted at the second end of the slave cylinder 221″. In an embodiment the slave cylinder cap 224 has an internal thread such the that the cap can apply a an adjustable and variably mechanical pressure on the damper 229. The adjustable position of the cap may further contribute to adjusting the travel range of the pedal in the first phase of the braking process before the mechanical stop 260 is engaged. The end bold 226 locks the cylinder cap 224 in place once it is in the desired position.
[0101] Equivalent to the previously described embodiments the region of the slave cylinder from the slave cylinder cap 224 to the damper piston 250 may be considered the damper housing. The chamber within the damper housing wherein the damper piston 250 is located may in some variants be wider than the slave cylinder chamber 221.
[0102] In a variant a damper 229 is located between the damper piston 250 and a damper bracket 251224. In other variants the one or more dampeners 229 are hollow cylinder-shaped elongated pieces of resilient material that are dimensioned such that when the system is in the relaxed default position the uncompressed dampener 229 extend from the damper piston 250 to the slave cylinder bracket 251. In yet other variants the one or more dampeners 229 may be a solid elongated piece of resilient material. In such variants having one or more solid dampers 229, each solid damper 229 may have a depression in either or both ends for engaging part of the damper piston 250 and/or damper bracket 251. In embodiments with a single solid dampener 229, the dampener may be mounted such that a flange of the damper piston 250 extends around a first end of the dampener 229 and a flange of the damper bracket extends around the second end of the dampener 229, such that when the dampener 229 is sufficiently compressed the flanges will come in mechanical contact and form a mechanical stop enabling the two-phase braking process. The resilient material of the dampener 229 may for example be rubber, silicone or similar known materials that are flexible and elastic. The resilient properties of the material, i.e. the force required to deform a dampener 229, influences the perceived softness of the pedal 101 in use. The less force is required to deform and/or compress the dampener 229 the softer the pedal 101 will be perceived by the user as less force will be required for a response. By the one or more dampeners 229 being elongated is to be understood that in such variants they are longer in the axial direction of the slave cylinder chamber 221 than they are wide in the transverse direction. In an embodiment such an elongated dampener 229 is cylinder-shaped. In another embodiment such an elongated dampener 220 is hollow which is a cylinder shaped hollow opening in a cylinder shaped resilient material, i.e. it is a resilient sidewall of a cylinder shape.
[0103] In an embodiment the shape of the damper piston 250 is such that a protrusion extends at least partially into the hollow opening of the cylinder-shaped dampener, thereby fixating and guiding the direction in which the damper 229 is bend it is deformed under pressure from the damper piston 250. In some variants the damper piston 250 may further comprise outer edges extending partially along the length of the of the dampener 229 for further fixating and controlling the dampener position. Furthermore the protrusion of the damper piston 250 may in some embodiments serve as a mechanical stop 260, limiting the travel range of the pedal 101 as well as limiting the compression of the damper 229 as the damper piston 250 can travel no further than to where the protrusion contacts the damper bracket 251 or the slave cylinder cap 224. A damper bracket 251 is placed between the damper 229 and the slave cylinder cap 224. The shape of the damper bracket 251 is such that a protrusion extends in the hollow opening of the cylinder-shaped dampener, thereby fixating and guiding the direction in the damper 229 is bend it is deformed under pressure from the damper piston 250. In some variants the damper bracket 251 may further comprise outer edges extending partially along the length of the of the dampener 229 for further fixating and controlling the dampener position. Furthermore the protrusion of the damper bracket 251 may in some embodiments serve as a mechanical stop 260, limiting the travel of the pedal 101 as well as limiting the compression of the damper 229. In a preferred embodiment damper piston 250 and damper bracket 251 are identical parts arranged with mirrored orientation.
[0104] The protrusion of the damper piston 250 optionally in combination with a protrusion of the damper bracket 251 or of the slave cylinder cap 224 provides a mechanical stop 260 which limits the travel range of the damper piston 250. Due to this limitation of the travel range of the damper piston 250 the user may experience two phases with different resistance when pressing the brake pedal. The first braking phase is experienced when the damper piston 250 is translating under the force of the pedal depression and the resistance is due to the deformation of the dampener 229. The second braking phase is experienced if the user continues to apply pressure after the protrusion of the damper piston 250 is in mechanical contact with the damper bracket 251, in this case the resistance the user will feel is due to the hydraulic pressure within the brake cylinder, that is from compressing the fluid within the brake cylinder system.
[0105] In an alternative embodiment the damper bracket 251 and the slave cylinder cap 224 is an integral part as shown in
[0106] In embodiments having multiple dampers 229 the damper piston 250 may have multiple protrusions for engaging the hollows of each damper 229. In such embodiments the damper piston 250 may further comprise protrusions extending between neighbouring dampers to further guide their bending during compression. Protrusions extending between neighbouring dampers 229 may also be present in embodiments where one or more dampers are made from a solid piece of resilient material, i.e. without a hollow extending through the damper.
[0107] During operation of the brake cylinder 201, applying pressure to the pedal 101 will lead to the master cylinder rod 205 being moved from its default position and translating further into the master cylinder chamber 215 towards the first end of the master cylinder chamber 215′. This movement of the master cylinder rod 205 leads to the master cylinder piston element 213 also translating in the direction towards the first end of the master cylinder 115′, thereby exerting a force on a fluid inside the master cylinder chamber 215 (similar to the situation described for the former embodiment and illustrated in
[0108] In one exemplary embodiment there may be two openings 219 each having a diameter of around 1.5 mm.
[0109] While the previously described embodiments have referred to one or more openings 219 in the wall 220 separating the master cylinder chamber 215 and the salve cylinder chamber 221, in other embodiments the fluidic exchange between the master cylinder chamber 215 and the slave cylinder chamber 221 may be through a differently arranged channel. For example the fluidic connection may be through a tube connecting the master cylinder chamber 215 and the salve cylinder chamber 221 externally of the brake cylinder 201. Such a configuration may be beneficial as it allows inspection of the fluid, e.g. through a transparent tube. The tube may also be connected through another device allowing treatment or affecting of the fluid. Furthermore it enables exchanging of the tube, e.g. to change its length or in case the tube is damaged or clogged. In yet another alternative embodiment the master cylinder chamber 215 and the salve cylinder chamber 221 may be fluidically connected though a channel arrange din the outer wall of the brake cylinder rather than in the wall 220 separating the chambers 215,221. Hence, the holes 219 should be interpreted as a specific embodiment of any type of channel arranged to fluidically connect the master cylinder chamber 215 and the salve cylinder chamber 221.
[0110] When the slave chamber piston element 223 is forced to move, it transfers force to the damper piston 250 which in turn is pressed in the same direction as the slave chamber piston element 223 moves, i.e. towards the dampener 229, the damper bracket 251 and the slave cylinder cap 224. This movement will lead to the compression and/or deformation of the dampener 229. The amount of force needed to elastically deform the dampener 229 depends on the material of choice of the dampener and may vary between embodiments to allow for different load of different brake cylinders to match user preference.
[0111] Simultaneously with the movement of the components of the brake cylinder 201 pressure is increased within the master cylinder chamber 215 and the slave cylinder chamber 221.
[0112] A pressure sensor 204 may be connected to and in fluid communication with the slave cylinder chamber 221 or the master cylinder chamber 215. There may be further openings in the cylinder chambers for fluid communication of other devices. The pressure sensor 204 is configured to measure the pressure in the brake cylinder 201. The pressure reading from the pressure sensor 204 may then be transmitted to the simulator and correlated to a braking force within the simulation. In the default position corresponding to no pressure being applied to the pedal (such as in the configuration shown on
[0113] Upon release of the pedal, i.e. when the user no longer applies pressure to the pedal, the brake cylinder system will return to its default position under the spring forces of the master cylinder spring 217, the slave cylinder spring 233, and the dampener 229 as the dampener 229 is decompressed, these forces move the slave chamber piston element 223 and the master cylinder piston element 213 back to their default position thereby also moving fluid which had been forced into the slave cylinder chamber 221 back into the master cylinder chamber 215.
[0114]
[0115] The shown embodiment of the push configuration comprises a master cylinder spring 217 arranged between the master piston element 213 and a master cylinder stop element 240 arranged at the first end of the master cylinder chamber 215′. Similarly a slave cylinder spring 233 is arranged between the slave cylinder piston element 233 and a slave cylinder rod guide 231. Both springs 217,233 are arranged to bias the system towards its default position.
[0116] The brake cylinder 201 further comprises a damper housing 227 integrated in the brake cylinder housing 203 with a dampener 229 arranged within. A block in the form of a damper piston 250 is arranged in contact with the slave cylinder rod on one side and the damper 229 on the other. A damper housing cap 225 is arranged at the end of the damper housing not facing the slave cylinder chamber 221. A damper bracket 251 is arranged between the damper housing cap 225 and the damper 229. In the embodiment shown in
[0117] The braking process and the feel of the pedal may be by exchanging the damper 229 using different resilient materials or springs to adjust how much force is required to compress the dampener 229. Different embodiments may further be adjusted by the length of the mechanical stop 260 of the block, damper piston and/or damper bracket, which adjusts how far the pedal can be depressed before the mechanical stop is reached.
[0118] The foregoing description has been presented for purposes of illustration. It is not exhaustive and does not limit the invention to the precise forms or embodiments disclosed. Modifications and adaptations of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed embodiments of the invention.
[0119] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.