Pressure Control Valve Arrangement Having an Eccentrically Mounted Double Magnet

Abstract

A pressure control valve arrangement for controlling fluid pressure in a brake system of a vehicle includes two diaphragm valves and two electromagnetic control valves, activatable by an electronic control device, for the pilot control of the diaphragm valves. The two electromagnetic control valves have a double magnet with two magnet coils and magnet armatures and are actuatable by current being applied to the magnet coils. The housing has at least one pressure medium connection, connected to a service brake valve, for acting with pressure upon and/or relieving the pressure of the pressure control valve arrangement and at least one connection for connecting to a brake cylinder. A plane of symmetry of the mid-axes of the magnet coils of the double magnet is arranged in parallel and offset by the amount of an eccentricity, with respect to a mid-axis of the pressure medium connection.

Claims

1. A pressure control valve for a brake system comprising: a housing; the housing having a service brake pressure connection having a mid-axis; a first diaphragm valve in the housing; a second diaphragm valve in the housing; a first electromagnetic valve in the housing having a first magnetic coil; a second electromagnetic valve in the housing having a second magnetic coil; the first magnetic coil and the second magnetic coil having a coil plane of symmetry parallel to the mid-axis of the service brake pressure connection; wherein the coil plane of symmetry is offset by an eccentricity value with respect to the mid axis of the service brake pressure connection.

2. The pressure control valve of claim 1, the housing further comprising a mounting bore having a mounting bore mid-axis, wherein the mounting bore mid-axis is perpendicular to and offset by the eccentricity value from the coil plane of symmetry.

3. The pressure control valve of claim 1, wherein the eccentricity value is greater than about one millimeter.

4. The pressure control valve of claim 1, further comprising a first cover, wherein a first control chamber is formed between a first diaphragm of the first diaphragm valve and the first cover.

5. The pressure control valve of claim 4, wherein the first cover is fastened generally laterally onto the housing.

6. The pressure control valve of claim 4, wherein the first cover is composed of plastic.

7. The pressure control valve of claim 4, further comprising a second cover fastened onto the housing, wherein a second control chamber is formed between a second diaphragm of the second diaphragm valve and the second cover.

8. The pressure control valve as in claim 7, wherein the second cover is arranged generally perpendicular from the first cover on the housing.

9. A pressure control valve arrangement for controlling the fluid pressure in an ABS brake system of a vehicle in such a way that, during a tendency of individual wheels of the vehicle to lock, the brake pressure in at least one assigned brake cylinder can be matched adaptively, comprising: two diaphragm valves and two electromagnetic control valves, activatable by an electronic control device, for the pilot control of the diaphragm valves being provided in the housing of the pressure control valve arrangement, the two electromagnetic control valves having a double magnet with two magnet coils and two magnet armatures cooperating with solenoid valve seats and actuatable by current being applied to the two magnet coils, the housing having at least one pressure medium connection, connected to a service brake valve, for acting with pressure upon and relieving the pressure of the pressure control valve arrangement and at least one working connection for connecting to the brake cylinder, a plane of symmetry of the mid-axes of the two magnet coils of the double magnet of the two electromagnetic control valves being arranged parallel, and offset by the amount of an eccentricity (e), with respect to a mid-axis of the pressure medium connection, and the housing being provided with at least one through bore which issues in side faces of the housing and is a holding means for holding the pressure control valve arrangement on a carrier body, the plane of symmetry of the mid-axes of the two electromagnetic control valves being arranged, offset by the amount of the eccentricity (e) with respect to a plane of symmetry of the at least one through bore, said plane of symmetry being arranged perpendicularly to a mid-axis of the through bore.

10. The pressure control valve arrangement according to claim 9, further comprising, in a first diaphragm valve of the two diaphragm valves, the surface normal running perpendicularly with respect to the first diaphragm is arranged parallel to the mid-axis of the at least one through bore and perpendicularly to the mid-axis of the pressure medium connection, and, in the second diaphragm valve, the surface normal running perpendicularly with respect to the second diaphragm is arranged perpendicularly to the mid-axis of the through bore and perpendicularly to the mid-axis of the pressure medium connection.

11. The pressure control valve arrangement according to claim 10, further comprising: a first cover closing a pilot control space of the first diaphragm valve with respect to the outside and fastened to the housing.

12. The pressure control valve arrangement according to claim 11, wherein the first cover is composed of plastic.

13. The pressure control valve arrangement according to claim 11, characterized in that the first cover closes a pressure medium duct formed in the housing and separated from the respective pilot control space.

14. The pressure control valve arrangement according to claim 11, wherein a second cover closes a pilot control space of the second diaphragm valve with respect to the outside and fastened to the housing.

15. The pressure control valve arrangement of claim 9, wherein the pressure medium connection is provided for connection to a service brake valve of a pressure medium-actuated brake apparatus of a vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows a basic illustration of an ABS brake system as a general diagram of a 4S/4C ABS brake system of a vehicle.

[0022] FIG. 2a shows a diagrammatical illustration of a pressure control valve arrangement activating a brake cylinder, in the open state (pressure build-up).

[0023] FIG. 2b shows a diagrammatic illustration of the pressure control valve arrangement of FIG. 2a in the closed state (pressure reduction).

[0024] FIG. 3 shows a front view of an actual version of the pressure control valve arrangement of FIG. 2a and FIG. 2b according to an exemplary embodiment of the present invention.

[0025] FIG. 4 shows a side view of the pressure control valve arrangement of FIG. 3.

[0026] FIG. 5 shows a sectional illustration along the line V-V of FIG. 4.

[0027] FIG. 6 shows the other side view of the pressure control valve arrangement of FIG. 3.

[0028] FIG. 7 shows a sectional illustration along the line VII-VII of FIG. 6.

DETAILED DESCRIPTION

[0029] FIG. 1 According to FIG. 1, a vehicle equipped with an ABS brake system has a front axle 1 and a rear axle 2. Wheels 3a and 3b are arranged on the front axle 1; the rear axle 2 has, for example, wheels 4a and 4b in each case equipped with twin tires. The ABS brake system serving for braking these wheels 3a, 3b and 4a, 4b is designed here in the manner of a 4S/4C system (four sensors, four channels). This means that, overall, four rotational speed sensors 5a-5d and four pressure control valve arrangements 7a-7d are available here. The pressure control valve arrangements 7a-7d serve for the activation of respectively assigned brake cylinders 6a-6d. All the pressure control valve arrangements 7a-7d are connected to a foot-operated brake valve 9 via a branching pneumatic brake pressure line 8.

[0030] The driver, when actuating the foot-operated brake valve 9, generates a brake pressure which, passing through the pressure control valve arrangements 7a-7d, is transferred by the pneumatic brake pressure line 8 to the brake cylinders 6a-6d assigned to the wheels 3a, 3b and to the wheels 4a, 4b.

[0031] The pressure control valve arrangements 7a-7d are activatable via integrated electromagnetic valves 15a, 15b shown in FIG. 2a, FIG. 2b and FIG. 4 and for this purpose are connected electrically to a central electronic control unit 10. The electronic control unit 10 is connected on the input side to the four rotational speed sensors 5a-5b determining the wheel speeds. In the event of the locking of a wheel 3a-3d, the brake pressure selected by the driver via the foot-operated brake valve 9 is lowered correspondingly to an ABS control, according to the electronic control unit 10, by the corresponding pressure control valve arrangements 7a-7d until locking is eliminated. The ABS brake system of the present exemplary embodiment comprises, furthermore, an ASR function which comprises an ASR unit 11 for reducing the engine torque, such as an ASR solenoid valve 12 and a shuttle valve 13.

[0032] The pressure control valve arrangement 7 used according to FIG. 2a within the framework of the ABS brake system for the purpose of ABS control is constructed here in the manner of a 1-channel pressure control valve arrangement and is composed essentially of two integrated diaphragm valves 14a and 14b and of two spring-loaded electromagnetic valves 15a, 15b activating these. The diaphragm valves 14a and 14b are in each case loaded in the closing direction by spring elements 16a, 16b and are pilot-controlled via the respectively assigned electromagnetic valves 15a and 15b.

[0033] A pressure control valve arrangement 7 is shown in FIG. 2a in its open position, in which a build-up of pressure to the connected brake cylinder 6 takes place. In this case, neither of the solenoid valves 15a and 15b is activated electrically. In the position shown, the compressed air coming from the foot-operated brake valve 9 presses onto the diaphragm valve 14a designed as an inlet valve. The normally closed electromagnetic valve 15a prevents the assigned diaphragm valve 14a from being closed again. By the normally open second electromagnetic valve 15b, the brake pressure coming from the foot-operated brake valve 9 closes the second diaphragm valve 14b serving as an outlet valve. The compressed air thus runs, unimpeded, through the pressure control valve arrangement 7. The pressure control valve arrangement 7 is in this state even when ABS control does not take place.

[0034] To keep the brake pressure constant in a brake cylinder 6a to 6d, current merely has to be applied to the electromagnetic valve 15a, with the result that this opens and consequently the brake pressure coming from the foot-operated brake valves 9 presses the inlet-side diaphragm valve 14a shut. The pressure on the right and the left side of the diaphragm valve 14a is then equal. However, since the active surface on the left side of the diaphragm valve 14a is greater, the diaphragm valve 14a is closed. The same applies correspondingly to the outlet-side diaphragm valve 14b activated via the electromagnetic valve 15b. To keep the pressure constant, therefore, the pressure control valve arrangement 7 closes the pneumatic brake pressure line 8 running from the foot-operated brake valve 9 to the brake cylinder 6.

[0035] According to FIG. 2b, a pressure reduction in a brake cylinder 6a to 6d is achieved in that current is applied to both electromagnetic valves 15a and 15b. What was described above for holding the pressure applies to the electromagnetic valve 15a and the assigned inlet-side diaphragm valve 15a. By contrast, the other electromagnetic valve 15b, by having current applied to it, is closed. The pressure coming from the brake cylinder 6 therefore presses the outlet-side diaphragm valve 14b open and the brake cylinder 6 is bled.

[0036] The above-described functions of the pressure control valve arrangement 7 are carried out according to the electronic control unit 10, within the framework of ABS/ASR control, in the way described initially.

[0037] FIG. 3 to FIG. 5 show the pressure control valve arrangement 7 illustrated merely diagrammatically in FIG. 2a and FIG. 2b in an actual embodiment in the installation position, that is to say the components illustrated at the top are located at the top. In this embodiment, the two electromagnetic valves 15a, 15b for the pilot control of the diaphragm valves 14a, 14b are combined in a double solenoid valve, the function of which, however, is analogous to that of the individual valves 15a, 15b.

[0038] The two electromagnetic valves 15a, 15b have a double magnet 18 combined in a block 17 and having two magnet coils 19a, 19b which cooperate with two solenoid valves seats 20a, 20b. As may be gathered clearly from FIG. 5, magnet armatures 36a, 36b cooperating with the solenoid valves seats 20a, 20b of the electromagnetic valves 15a, 15b are actuated as valve closing members by current being applied to the magnet coils 19a, 19b.

[0039] The block 17 comprising the double magnet 18 is fastened, which may be on the front side, to a housing 21 of the pressure control valve arrangement 7 and has a plug connection 22 for supplying current to the double magnet 18. This housing 21 has, furthermore, a pressure medium connection 23 for the action of pressure upon and/or the relief of pressure of the pressure control valve arrangement 7, and also a working connection 24, as can be seen in FIG. 4, for connecting the brake cylinder 6.

[0040] As shown in FIG. 2a and FIG. 2b, the pressure medium connection 23 is connected via the brake pressure line 8 to the foot-operated or service brake valve 9 of the pressure medium-actuated brake apparatus and is ventilated or bled according to actuation of the foot-operated brake valve 9.

[0041] As many be gathered particularly from FIG. 5, the mid-axes 25a, 25b of the magnet coils 19a, 19b are coaxial with the solenoid valve seats 20a, 20b of the electromagnetic valves 15a, 15b, and in each case one solenoid valve seat 20a, 20b is formed at one end of a pressure medium duct 26a, 26b which connects the respective solenoid valve seat 20a, 20b to the pressure medium connection 23.

[0042] A plane of symmetry 27, shown in FIG. 3, of the mid-axes 25a, 25b of the magnet coils 19a, 19b of the double magnet 18 of the two electromagnetic valves 15a, 15b is arranged, offset eccentrically by the amount of an eccentricity e with respect to a mid-axis 28 of the pressure medium connection 23. The mid-axis 28 of the pressure medium connection 23 is parallel with respect to this plane of symmetry 27.

[0043] The distance between the mouth of, for example, the pressure medium duct 26 in the pressure medium connection 23 and the mid-axis 28 of the pressure medium connection 23 is then reduced, because the mid-axis 25a of one of the magnet coils 19a of the double magnet 18 and consequently also the solenoid valve seat 20a of the respective electromagnetic valve 15a and also the respective pressure medium duct 26a are then moved nearer to the mid-axis 28 of the pressure medium connection 23, and consequently the pressure medium duct 26a can then issue into the pressure medium connection 23 at a shorter distance from said mid-axis, as shown clearly in FIG. 5. Of course, the double magnet 18 may also be arranged, offset by the amount of an eccentricity e, in the other direction, in FIG. 3 to the right with respect to the mid-axis 28 of the pressure medium connection 23.

[0044] According to the eccentricity e, however, the distance of the other pressure medium duct 26b emanating from the solenoid valve seat 20b of the other electromagnetic valve 15b from the mid-axis 28 of the pressure medium connection 23 is increased. This pressure medium duct 26b therefore does not issue directly into the pressure medium connection 23, but instead first, for example, into an annular duct 29 which is formed in the housing 21 and which is connected, in turn, to the pressure medium connection 23. The eccentricity may amount to more than 1 mm.

[0045] The housing 21 is provided with at least one, here, for example, two, through bores 31a, 31b which issue into the two side faces 30a, 30b of the housing 21 and through which a project holding arrangement, for example screws, for holding the pressure control valve arrangement on a carrier body, for example on a chassis of the vehicle. The mid-axes 32a, 32b of the two through bores 31a, 31b may be parallel to one another.

[0046] In this case, the plane of symmetry 27 of the mid-axes 25a, 25b of the magnet coils 19a, 19b of the double magnet 18 of the two electromagnetic valves 15a, 15b is arranged eccentrically with respect to a plane of symmetry 33 arranged perpendicularly to the mid-axes 32a, 32b of the through bores 31a, 31b, as may be gathered from FIG. 3. In this case, the mid-axis 28 of the pressure medium connection 23 lies in this plane of symmetry. The axial length of the through bores 31a, 31b is deemed a standardized installation dimension of the pressure control valve arrangement 7 and, for reasons of space, is fixed and invariable, and it defines the maximum permissible width B of the housing 21.

[0047] One diaphragm valve 14a may be arranged laterally and the other diaphragm valve 14b may be arranged on the bottom side on the housing 21, as shown in FIG. 4 and FIG. 7.

[0048] Such a diaphragm valve 14a, 14b has, as a valve body, a diaphragm 34a, 34b which can be acted upon by pressure medium being introduced into a control chamber 38a, 38b which is covered in each case on the housing outside by a cover 35a, 35b which is produced by primary forming, such as injection molding, and which is fastened to the housing 21. In this case, the control chamber 38a, 38b is formed between the diaphragm 34a, 34b and the cover 35a, 35b. The covers 35a, 35b may be composed of at least one plastic.

[0049] At least one of the covers 35a, 35b may be designed such that, in addition to its function as a closing body for the assigned control chamber 38a, 38b, it at the same time closes a bore which is formed in the housing 21 and is not intended for connection to the control chamber 38a, 38b and which issues into a side face 30a, 30b of the housing 21.

[0050] With regard to one diaphragm valve 14a of the two diaphragm valves 14a, 14b, the surface normal running perpendicularly with respect to the assigned diaphragm 34a may be parallel to the mid-axes 32a, 32b of the through bores 31a, 31b and perpendicular to the mid-axis 28 of the pressure medium connection 23, as can easily be imagined from FIG. 3. As regards the other diaphragm valve 14b, by contrast, the surface normal running perpendicularly with respect to the assigned diaphragm 34b is arranged perpendicularly to the mid-axes 32a, 32b of the through bores 31a, 31b and perpendicularly to the mid-axis 28 of the pressure medium connection 23. In other words, in the view of FIG. 3, one diaphragm valve 14a is then arranged laterally and the other diaphragm valve 14b on the bottom side or, alternatively, on the head side on the housing 21.

[0051] The List of Reference Symbols is as follows:

[0052] 1 Front axle

[0053] 2 Rear axle

[0054] 3 Wheel

[0055] 4 Wheel

[0056] 5 Rotational speed sensor

[0057] 6 Brake cylinder

[0058] 7 Pressure control valve arrangement

[0059] 8 Brake pressure line

[0060] 9 Foot-operated brake valve

[0061] 10 Control unit

[0062] 11 ASR unit

[0063] 12 ASR solenoid valve

[0064] 13 Shuttle valve

[0065] 14a/b Diaphragm valve

[0066] 15a/b Electromagnetic valve

[0067] 16a/b Spring element

[0068] 17 Block

[0069] 18 Double magnet

[0070] 19a/b Magnet coils

[0071] 20a/b Solenoid valve seats

[0072] 21 Housing

[0073] 22 Plug connection

[0074] 23 Pressure medium connection

[0075] 24 Working connection

[0076] 25a/b Mid-axes magnet coils

[0077] 26a/b Pressure medium duct

[0078] 27 Plane of symmetry

[0079] 28 Mid-axis

[0080] 29 Annular duct

[0081] 30a/b Side faces

[0082] 31a/b Through bores

[0083] 32a/b Mid-axes

[0084] 33 Plane of symmetry

[0085] 34a/b Diaphragm

[0086] 35a/b Cover

[0087] 36a/b Magnet armature

[0088] 38a/b Control chamber