Lock actuator, and park lock comprising such a lock actuator

Abstract

A vehicle park lock actuator is arranged in a longitudinal axis and has a movable actuating element which is movable into a first position and a second position. A locking slotted guide, and a locking element is held displaceably perpendicular to the longitudinal axis and has a first surface and a second surface at a different distance from the longitudinal axis, and connected by a wedge surface with a gradient. The first surface is in operative contact with the locking element in the first position and a second surface is in operative contact with the locking element in the second position. At least the first surface and/or the second surface is inclined in relation to the wedge surface.

Claims

1. An electromagnetic lock actuator (1) for a park lock (2), which is arranged in a longitudinal axis (X-X), comprising: an electromechanically movable and actuatable actuating element (10), which can be moved into a first position (A) and into a second position (B) and comprises a locking slotted guide (20), the locking slotted guide (20) comprising a sleeve, the sleeve being arranged on the actuating element (10); and at least one locking element (15) which is held displaceably relative to the locking slotted guide (20) to fix a cylinder (70) in the first position (A), wherein the locking slotted guide (20) has a first surface (21) and a second surface (22), which are connected to a gradient (M1) by a wedge surface (23), wherein the first surface (21) contacts the at least one locking element (15) in the first position (A), and wherein the second surface (22) contacts the at least one locking element (15) in the second position (B), wherein the first surface (21) is inclined in relation to the wedge surface (23) with a second gradient (M2), wherein a return spring (14) is provided, the return spring (14) holding the actuating element (10) in a preloaded actuator starting position in the first position (A), wherein the slotted guide (20) is held against a flange (26) of the actuating element (10) by means of the return spring (14), such that the first surface (21) forces the at least one locking element (15) to fix the cylinder (70) in the first position (A), and wherein the at least one locking element (15) is held within at least one notch (76, 77) of a sliding bush (75) in the first position (A), the at least one notch (76, 77) being defined by at least one surface such the at least one locking element (15) simultaneously contacts the at least one surface at two contact areas (C1, C2) in the first position (A).

2. The lock actuator (1) according to claim 1, characterized in that the gradient (M1) of the wedge surface (23) and the second gradient (M2) of said first surface is at most 2:1.

3. The lock actuator (1) according to claim 1, characterized in that the gradient (M1) of the wedge surface (23) and the second gradient (M2) of said first surface points in the same direction.

4. The lock actuator (1) according to claim 1, characterized in that the actuating element (10) is linearly movable in the longitudinal axis (X-X), or that the actuating element (10) is rotatable about the longitudinal axis (X-X).

5. The lock actuator (1) according to claim 1, characterized in that an actuator housing (30) is provided, and that the actuating element (10) and the at least one locking element (15) are mounted in the actuator housing.

6. The lock actuator (1) according to claim 1, characterized in that the at least one locking element (15) is a locking ball.

7. A park lock (2), with the lock actuator (1) according to claim 1, wherein the cylinder (70) can be lifted in the longitudinal axis (X-X).

8. The park lock (2) according to claim 7, characterized in that the at least one notch (76, 77) is formed in the sliding bush (75), and wherein the two contact areas (C1, C2) are spaced apart from a line (L) which runs through a geometric center point (S) of said at least one locking element (15).

9. The park lock (2) according to claim 8, characterized in that the two contact areas (C1, C2) are arranged in the longitudinal axis (X-X) on opposite sides of the line (L).

10. The park lock (2) according to claim 8, characterized in that the at least one notch (76, 77) is U-, V- or trapezoid-shaped.

11. A motor vehicle with automatic transmission, having at least one park lock (2) according to claim 7.

12. A park lock (2) for use in a motor vehicle with automatic transmission, with the lock actuator (1) according to claim 1, wherein the cylinder (70) can be lifted in the longitudinal axis (X-X).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the present invention according to the invention and a further development thereof are explained in detail below with reference to the accompanying drawings. In the drawings:

(2) FIG. 1 is a schematic sectional view of a park lock of a motor vehicle with a lock actuator according to the invention, wherein a cylinder of the park lock is fixed in a first position by the lock actuator,

(3) FIG. 2 is a schematic sectional view of a park lock according to FIG. 1, wherein the cylinder of the park lock is fixed in a second position by the lock actuator,

(4) FIG. 3 shows an enlarged illustration of the lock actuator according to the invention according to FIG. 1 or 2 with an actuating element and a locking slotted guide arranged on the actuating element, which is set up to provide the at least one locking element for locking the cylinder of the park lock,

(5) FIG. 4 shows a further development of the park lock according to FIGS. 1 to 3, and

(6) FIG. 5 shows an enlarged illustration of the latching link of the park lock according to FIG. 4.

DETAILED DESCRIPTION

(7) FIGS. 1 and 2 show a park lock 2 according to the invention with a lock actuator 1 and a cylinder 70 or piston 70 arranged in a cylinder housing 60 and movably arranged in the cylinder housing 60 in a longitudinal axis X-X.

(8) The cylinder 70 of the park lock 2 can be shifted along a longitudinal axis X-X between a first position (see FIG. 1) and a second position (see FIG. 2) in order to mechanically lock a transmission (not shown), in particular an automatic transmission of a motor vehicle. The first position of the cylinder 70 can correspond to the position of the cylinder 70 locking the transmission and the second position B can correspond to the position of the cylinder 70 releasing the transmission, or vice versa.

(9) The lock actuator 1 is arranged on the longitudinal axis X-X and has a first side 11 and a second side 12, the second side 12 facing the cylinder 70 and the cylinder housing 60 and the first side 11 forming the free end of the lock actuator 1.

(10) The lock actuator 1 comprises an electromagnetic actuator 5, a coil 7 that can be energized, an armature 8, an actuating element 10, a locking slotted guide 20, a return spring 14, a pole cover 9 and an actuator housing 30.

(11) The electromagnetic actuator 5 is designed in the manner of a single solenoid which, by means of an electromagnetic force action of the energized coil 7, causes a linear movement of the armature 8 and an actuating element 10 connected to the armature 8 in the longitudinal axis X-X from an actuator starting positionwhich is shown in FIGS. 1 and 2into an actuator end position (not shown). The return takes place through the spring force of the return spring 14. The actuator starting position corresponds to a first position A of the actuating element 10 and the actuator end position corresponds to a second position B of the actuating element.

(12) The actuator housing 30 of the lock actuator 1 comprises a first housing section 31 and a second housing section 32, the first housing section 31 closing the first side 11, i.e., the free end of the lock actuator 1, and the second housing section 32 being arranged on the side of the lock actuator 1 facing the cylinder housing 60. The first housing section 31 and the second housing section 32 are each made in one piece from a magnetic and metallic material and serve to guide the magnetic flux that results from energizing the coil 7.

(13) The second housing section 32 furthermore comprises a flange 34, a shoulder 35 that forms a cylinder lateral surface and a housing sleeve 33 protruding from the second side.

(14) The actuating element 10 is connected to the armature 8 and is mounted at one end on the first side 11 of the electromagnetic actuator 5 in a through hole in the pole cover 9 and at the other end in the second housing section 32 or in the housing sleeve 33 molded onto the second housing section 32.

(15) When the coil 7 is energized, the armature 8 together with the actuating element 10 is moved from the stroke start position along the longitudinal axis X-X against the force of the return spring 14. The return spring 14 is supported at one end in the actuator housing 30 or in the housing sleeve 33 of the second housing section 32 and at the other end on a free end, which is arranged on the second side and which is provided with a flange. The armature 8 is held in the second housing section 32 for a flux transition both in the actuator starting position and in the actuator end position, the pole cover 9 and the armature 8 being spaced apart in the actuator starting position. In the actuator end position, the air gap between the armature 8 and the pole cover 9 is closed, with a sleeve-shaped section being formed on the side of the pole cover 9 facing the armature 8, which is designed to encompass the armature 8 in the actuator end position.

(16) It can be advantageous for the sleeve-shaped section to be designed as a control cone. The free end of the sleeve-shaped section can be arranged approximately in a plane perpendicular to the longitudinal axis X-X on the end of the armature 8 facing the pole cover 9. Furthermore, the free end of the sleeve-shaped section is arranged at a distance from the second housing section 32.

(17) The lock actuator 1 is set up to lock the piston-shaped cylinder 70 in the first positionsee FIG. 1and in the second positionsee FIG. 2. For this purpose, the at least one locking element 15 and the locking slotted guide 20 are arranged on the second side 12 of the lock actuator 1 facing the cylinder 70. For this purpose, the locking slotted guide 20 is coupled to the actuating element 10, the locking slotted guide being set up to advance the at least one locking element 15 for fixing or locking the cylinder 70 in the first position or the second positionas will be explained in detail below.

(18) The cylinder housing 60 is made of a plastic and has a through opening 63 that is coaxial with the longitudinal axis X-X and extends between a first side 61, which faces the electromagnetic actuator 5, and a second side 62. In the through opening 63, the cylinder 70 is movably arranged in the longitudinal axis X-X.

(19) The cylinder housing 60 is firmly connected to the actuator housing 30 at a connection point 50, the cylinder housing 60 in the illustrated preferred exemplary embodiment being pushed onto the first housing section 31 via a cylinder lateral surface of the shoulder 35 until the first side 61 of the cylinder housing 60 lies against the end face of the flange 34. Alternatively, a gap can be formed between the cylinder housing 60 and the end face of the flange 34, which can serve to compensate for tolerances.

(20) A metal-plastic connection is then produced between the actuator housing 30 and the cylinder housing 60, the metal-plastic connection being particularly preferably produced by an ultrasonic welding process. Alternatively, the cylinder housing 60 can be molded directly onto the actuator housing 30 in a forming process, in particular injection molding.

(21) In order to give the metal-plastic connection a particularly good strength, both the end face of the flange 34 and the cylinder lateral surface of the shoulder 35 can be provided with a surface enlargement, for example a corrugation or at least one undercut 36, whereby in particular high axial forces along the longitudinal axis X-X can be transmitted via the metal-plastic connection.

(22) The cylinder 70 is formed in one piece from essentially two tubular sections and can be produced from a plastic, preferably in an injection molding process. The first tubular section 71 and the second tubular section 72 are connected to one another in a transition region 73.

(23) The first section 71, together with the transition region 73 and the cylinder housing 60, encloses a pressure chamber 65 which can be closed in a liquid-tight and airtight manner by means of seals 56. Furthermore, the first section 71 engages in a hollow-cylindrical cavity enclosed between the housing sleeve 33 and the cylinder housing 60, so that the first section 71 is guided linearly on the housing sleeve 33 on the one hand and on the cylinder housing 60 on the other.

(24) The cylinder housing 60 can have at least one control opening 66, through which a medium can be introduced into the pressure chamber 65 in order to move the cylinder 70 against the spring force of a compression spring 80 from the first position to the second position along the longitudinal axis X-X. The cylinder 70 is thus a single-acting cylinder.

(25) The cylinder 70 is guided in the first tubular section 71 on the housing sleeve 33, the first tubular section 71 having a sliding bush 75 through which the cylinder 70 is linearly slide-mounted on the housing sleeve 33. The sliding bush 75 can be made of a metallic material and the cylinder 70 is particularly preferably overmolded onto the sliding bush 75, whereby the latter is held in a form-fitting manner on the inner lateral surface of the first tubular section 71 of the cylinder 70. The sliding bush 75 comprises a first notch 76 and a second notch 77, which are spaced apart from one another in the longitudinal axis X-X and form a latching link 74. The distance between the first notch 76 and the second notch 77 corresponds to the stroke of the cylinder 70 between the first position according to FIG. 1 and the second position according to FIG. 2.

(26) On the side of the transition region 73 facing away from the first tubular section 71, a spring shoe 78 is formed within the second tubular section 72. A park lock tappet 85 is supported on the spring shoe 78, the compression spring 80 holding the park lock tappet 85 pressed against the spring shoe 78 in the longitudinal axis X-X.

(27) The second side 62 of the cylinder housing 60 is closed by means of a cover 67, which has a through opening 68, through which the park lock tappet 85 can be guided toward the transmission. A sliding element, which supports the park lock tappet 85, can be arranged in the through opening 38. The sliding element can be made of any material, for example metal or PTFE, and can preferably be pressed into a corresponding recess in the cover 67, glued or fastened to the cover 67 in some other way.

(28) The compression spring 80 can be held preloaded by means of a spring plate 69 between the park lock tappet or the spring shoe 78 and the spring plate 69 or the cover 67, so that, when pressure is applied to the pressure chamber 65, the cylinder 70 is moved from the first position A to the second position B in the longitudinal axis X-X against the spring force of the compression spring 80.

(29) The lock actuator 1 fixes the cylinder 70 in the first position or the second position, the lock actuator 1 being able to fix or release the cylinder 70 by means of the locking slotted guide 20 coupled to the actuating element 10 and the at least one locking element 15.

(30) For this purpose, the at least one locking element 15 is designed as a locking ball and is held in a recess 38 in the housing sleeve 33 or the second housing section 32 and is movably supported in the recess 38 substantially perpendicular to the longitudinal axis X-X. The recess 38 can have a cylindrical shape perpendicular to the longitudinal axis X-X and can correspond to the shape of the at least one locking element 15 in such a way that the locking element 15 is held in the recess 38, so that it can move easily perpendicular to the longitudinal axis X-X. In particular it can be seen on the enlarged illustration in FIG. 3 that the recess 38 has a retaining edge 39 on the side facing away from the locking slotted guide 20, by means of which the recess 38 is tapered on the one facing the latching link 74. The retaining edge 39 is set up in such a way as to prevent the relevant locking element 15 from falling out of the recess 38, in particular during the assembly of the lock actuator 1 according to the invention or the park lock 2 according to the invention. Depending on the position of the cylinder 70, the at least one locking element 15 can engage in the first notch 76 or in the second notch 77 of the latching link 74 and thereby fix the position of the cylinder 70 relative to the actuator housing 30.

(31) The locking slotted guide 20 can be arranged fixedly on the actuating element 10 and comprises a first surface 21, a wedge surface 23 and a second surface 22.

(32) The enlarged illustration in FIG. 3 shows that the wedge surface 23 connects the first surface 21 to the second surface 22 and has a gradient M1. The diameters of the first surface 21 and the second surface 22 are dimensioned differently. When the first surface 21 is in operative contact with the locking element 15, the locking element 15 engages in the relevant notch 76, 77. If, on the other hand, the second surface 22 is in operative connection with the locking element 15, the locking element 15 can leave the relevant notch 76, 77 and a movement of the cylinder 70 in the longitudinal axis X-X is enabled.

(33) The first surface 21 is inclined in relation to the wedge surface 23 with a second gradient M2, whereby the first surface 21, in contrast to the second surface 22, is not a cylinder lateral surface, but is conical with the second gradient M2.

(34) The gradient M1 of the wedge surface 23 is always larger in magnitude than the second gradient M2, the first gradient M1 preferably being at least twice as large as the second gradient M2 of the first surface 21. In the exemplary embodiment shown, the second gradient M2 is approximately one tenth of the gradient M1, that is to say approximately 10*M2M1, the second gradient M2 also being up to 1/25*M1 and less. The gradient M1 and the second gradient M2 correspond to the mathematical gradient of a curve or line and are calculated in the illustrated embodiment using the change in the radius of the wedge surface 23 or the first surface 21 along the longitudinal axis X-X, i.e., M1=r/x or M2=r/x. The mathematical sign, i.e., plus (+) or minus (), of the gradient M1 and the second gradient M2 is the same. Accordingly, the first surface 21 and the wedge surface 23 are inclined in the same direction.

(35) The second gradient M2 of the first surface 21 can preferably be selected such that the locking element 15 and the locking slotted guide 20 cannot be moved in the position A against the spring force of the return spring 14. When the cylinder 70 is loaded with an axial load force, the force required to adjust the actuating element 10 is significantly reduced by the second gradient M2 of the first surface 21. Consequently, the electromagnetic actuator 5 can be made smaller.

(36) In position A, the locking element 15 or the locking elements 15 rest at a contact point P on the first surface 21, the contact point P being arranged at a distance D from the wedge surface 23. The distance D can be 2 mmD0.25 mm, preferably approximately 1 mm, the distance D being related to a transition edge between the wedge surface 23 and the first surface 21.

(37) The locking slotted guide 20 can be placed as a sleeve 25 on the actuating element 10 and held against a flange 26 of the actuating element 10 by means of the return spring 14.

(38) FIG. 4 shows a further development of the park lock 2 according to FIGS. 1 to 3. The park lock 2 shown in FIG. 4 differs from the park lock 2 described above in the design of the sliding bush 75 or the latching link 74.

(39) As illustrated in the further development shown, the sliding bush 75 can only have a first notch 76, in which the locking element 15 for fixing the cylinder 70 in the first positionas described aboveis formed. The second notch 76 can be formed by an end section of the sliding bush 75 and the piston 70, whereby material savings and a further reduction in weight can be achieved.

(40) The notch 76 is trapezoidal and has two surfaces F1, F2, each with a contact area C1 and C2. At the respective contact areas C1 and C2, the locking element 15 makes contact with the notch 76 when it engages in the latching link 74.

(41) The notch 76 has an open side on the side facing the longitudinal axis X-X, the length of whichmeasured parallel to the longitudinal axis X-Xis smaller than the length of the locking element 15, also measured parallel to the longitudinal axis X-X. It can also be seen that the two surfaces F1 and F2 are arranged inclined in relation to one another and enclose an opening angle of approximately 90. The notch 76 tapers with increasing distance from the longitudinal axis X-X.

(42) When the locking element 15 engages in the notch 76, the two contact areas C1 and C2 are arranged spaced apart from a line L. The line L projects radially or perpendicularly from the longitudinal axis X-X and runs through a geometric center point S of the locking element. In the present case, the two contact areas C1 and C2 are arranged in the longitudinal axis X-X on opposite sides of the line L.

(43) The locking element 15 can be designed as desired, but a locking ball with a substantially constant diameter is preferred. In this case, a line runs through the center point S of the locking ball and the two contact areas C1 and C2 are arranged on both sides and at a distance from the line. The distance in the longitudinal axis X-X of the two contact areas C1 and C2 is smaller than the diameter of the locking ball and greater than approximately 1/10 of the diameter of the locking ball.

(44) If the locking element 15 contacts the contact areas C1, C2, which ideally are also contact points, neglecting deformations and friction, the notch 76, a resulting force in these contact areas C1, C2 does not act parallel or perpendicular to the longitudinal axis X-X, but preferably at an angle of about 45 to the longitudinal axis, whereby the force for unlocking the locking device 1 of the park lock 2 is reduced.

LIST OF REFERENCE NUMERALS

(45) 1 Lock actuator 2 Park lock 5 Actuator 7 Coil 8 Armature 9 Pole cover 10 Actuating element 11 First side 12 Second side 14 Return spring 15 Locking element 20 Locking slotted guide 21 First surface 22 Second surface 23 Wedge surface 25 Sleeve 26 Flange 30 Actuator housing 31 First housing section 32 Second housing section 33 Housing sleeve 34 Flange 35 Shoulder 36 Undercut 38 Recess 39 Retaining edge 50 Connection point 56 Seal 60 Cylinder housing 61 First side 62 Second side 63 Through opening 65 Pressure chamber 66 Control opening 67 Cover 68 Through opening 69 Spring plate 70 Cylinder 71 First section 72 Second section 73 Transition region 74 Latching link 75 Sliding bush 76 First notch 77 Second notch 78 Spring shoe 80 Compression spring 85 Park lock tappet C1 Contact area C2 Contact area D Distance F Surface L Line M1 First gradient of 23 M2 Second gradient of 21 and/or 22 P Contact point S Geometric center point of 15 X-X Longitudinal axis Opening angle