Parking lock for a transmission with a parking lock gear wheel

Abstract

The present invention relates to a parking lock (1) for a transmission of a motor vehicle, the transmission having a parking locking gear (2), the parking lock including a pawl (3) configured to cooperate with the teeth of the parking locking gear (2) to release rotation of the parking locking gear (2) in an unlocked position, and to engage with the teeth of the parking locking gear (2) in a locked position and lock rotation of the parking locking gear (2), wherein the pawl (3) is operable via an operating unit (4) and is pivotally disposed at a first pin (6a) about a rotation axis (5); a first plate element (7a) and a second plate element (6a) are also included. Two plate elements (7b), the first plate element and the second plate element constituting for absorbing force when the pawl (3) engages in the teeth of the parking lock gear (2), wherein a first pin (6a) is received in a corresponding hole (8a, 8b) at each of the two plate elements (7a, 7b); and a second pin (6b) and a third pin (6c), the second pin and the third pin being received in holes (8c, 8d, 8e, 8f) at each of the two plate elements (7a, 7b) and constituting for supporting the two plate elements (7a, 7b) at the transmission housing (9).

Description

Technical Field

[0001] The present invention relates to a parking lock for a transmission of a motor vehicle, the transmission having a parking locking gear, the parking lock including a pawl configured to cooperate with the teeth of the parking locking gear to release rotation of the parking locking gear in an unlocked position, and to engage with the teeth of the parking locking gear in a locked position and lock rotation of the parking locking gear. Background Technology

[0002] When operated by the driver of a motor vehicle, the parking lock engages with the parking lock gear by means of a pawl to prevent rotation of the drive shaft or driven shaft of the motor vehicle that is effectively connected to the parking lock gear, thereby preventing the motor vehicle from rolling away.

[0003] For example, a parking lock for an automatic transmission in a motor vehicle is known from DE 101 44 056A1. This parking lock has a locking ring disposed on the transmission shaft and a pivotally supported pawl that engages in a locking recess of the locking ring in the locked state. Furthermore, the parking lock includes a similarly pivotally supported shift lever that acts on a linkage at one end of which a roller is received, wherein a first roller acts on a ramp profile of the pawl away from the back of the locking ring. An operating unit for actuating the pawl is provided substantially parallel to the pawl. Other parking locks are known from EP 3 744 586 A1, CN 108 087 545A, DE 10 2019 134 432A1, and DE 102010 061 171A1. In order to reliably withstand the maximum torque generated when the parking lock is suddenly engaged, many parking locks are either solidly constructed or require sufficient structural space, which allows the maximum torque to be reduced or extended over time through the rigidity of the components and their internal friction, making the parking lock durable. Summary of the Invention

[0004] The purpose of this invention is to provide an alternative parking lock that requires little structural space, is easy to install, and has improved durability.

[0005] Parking locks are typically part of a vehicle's transmission. They can also be located on the vehicle's electric axle in the absence of a transmission. The parking lock includes a pawl that engages in a shape-fitting manner with a parking lock gear. The pawl is pivotable about an axis. For this purpose, the pawl can be mounted on a pin. If the pawl is directly supported on the transmission housing via a single pin, such that the torque generated when the pawl engages with the teeth of the parking lock gear is directly introduced through the pin into the support portion of the transmission housing, the support portion of the transmission housing may be damaged due to this so-called rotor impact. The pin can be constructed as a pin independent of the housing, but it can also be constructed as a cylindrical protrusion within the housing.

[0006] Because the first pin housing the pawl is not directly supported at the transmission housing, but rather indirectly via two plate elements and the second and third pins, the force generated when the pawl engages with the teeth of the parking lock gear is distributed such that a small portion of the rotor impact reaches the four support points of the second and third pins at the housing. This allows for simpler implementation of the support points at the transmission housing, eliminating the need for additional reinforcements at the housing support points to accommodate the pins. This optimized force flow begins at the pawl and extends via the first pin to the two plate elements, and further via the second and third pins to the four support points at the transmission housing. Furthermore, the plate elements connecting the pins can be reversibly deformed in a restricted manner, thereby reducing a portion of the rotor impact. Another advantage is that the pawl, the two plate elements, the three pins, and the operating unit form a single unit, namely the parking lock, which can be pre-installed into the transmission housing.

[0007] In a preferred design, the parking lock is attached to the housing only by the second and third pins, eliminating the need for other pins.

[0008] The two plate elements of the parking lock serve as guard plates and accommodate the bolt pin. For this purpose, the plate elements may have openings, such as channels or holes. Preferably, the two plate elements are manufactured using a cold-forming technique. The two plate elements may be configured as two-dimensional plates and are preferably arranged parallel to each other.

[0009] When the pawl is operated by the control unit, there is a locked position of the pawl, causing it to pivot about the axis of rotation and engage at least partially with the teeth of the parking lock gear in a form-fit. The form-fit between the pawl and the parking lock gear prevents rotation of the parking lock gear. Therefore, the pawl prevents the corresponding shaft of the motor vehicle from being effectively connected to the parking lock gear, especially the drive shaft or driven shaft of the motor vehicle.

[0010] According to the example, there exists an unlocked position for the pawl when it is not operated by the actuation unit and therefore does not pivot about the axis of rotation. The unlocked position corresponds to the output or neutral position of the pawl. In other words, the pawl is passive in the unlocked position and does not engage its locking section with the teeth of the parking lock gear, so that the parking lock is not engaged and therefore does not prevent the drive shaft or driven shaft of the vehicle. Therefore, the pawl releases rotation of the parking lock gear in its unlocked position.

[0011] Preferably, the actuating unit includes a roller box, a guide rod, and a spring element, wherein the roller box abuts against the pawl and can move axially in the longitudinal direction of the guide rod to actuate the pawl. In other words, the roller box of the actuating unit actuates the pawl between a locked position and an unlocked position. The roller box can be switched via an actuator or can move axially in the longitudinal direction of the guide rod.

[0012] According to a preferred embodiment of the invention, the roller box includes a first roller and a second roller, a roller rail wall, two side walls for receiving and supporting the two rollers, and a support wall effectively connected to a guide rod, wherein the first roller abuts against the roller rail wall, and wherein the second roller abuts against the pawl. Furthermore, the two rollers of the roller box abut against each other. The second roller is supported on a ramp of the pawl. The ramp is located on the side of the pawl opposite to the pawl teeth in the groove that engages with the parking lock gear.

[0013] For example, when the roller box moves axially against the spring force of the spring element in the longitudinal direction of the guide rod, the pawl is introduced into an unlocked position. Here, the roller box slides along the ramp at the pawl via the first roller on the roller rail wall and via the second roller, causing the pawl teeth to disengage from the tooth groove. According to this example, when the roller box moves axially in the longitudinal direction of the guide rod and in the direction of the spring force of the spring element, the pawl is introduced into a locked position. Here, the roller box slides along the ramp at the pawl via the first roller on the roller rail wall and via the second roller, causing the pawl teeth to be pressed into the tooth groove.

[0014] According to a preferred embodiment of the invention, stop surfaces are respectively formed at two plate elements for abutting the roller box in the unlocked position. The two stop surfaces are configured to limit the adjustment path for the roller box. In particular, the roller box abuts against the two stop surfaces of the plate elements by means of two sidewalls in the unlocked position.

[0015] Preferably, a tension spring is provided at the pawl for returning the pawl to the unlocked position, wherein the tension spring abuts at least at the pawl and at least one of the two plate elements. For example, the tension spring is configured as a torsion spring and housed at the first pin, wherein a first end portion of the tension spring is located at the pawl, and wherein a second end portion of the tension spring is located at at least one of the two plate elements. When the roller box moves against the spring force of the spring element, the pawl is pulled out of the toothed groove of the parking lock gear by means of the tension spring, thereby releasing the rotation of the parking lock gear.

[0016] According to a preferred embodiment of the invention, the second and third pins are respectively arranged parallel to the axis of the first pin, wherein the first pin is spatially disposed between the second and third pins. For this purpose, the second, first, and third pins can be arranged collinearly. If the first pin is not directly on the connecting line, but slightly offset from it, the first pin is still spatially positioned between the two other pins. The offset is preferably small enough that the triangle formed by the three pins has an obtuse angle at the first pin.

[0017] Furthermore, preferably, at least the second and third pins are identically constructed. In particular, the two plate elements are identically constructed. Preferably, all holes at the two plate elements substantially do not include clearance from the corresponding pin or include a minimum clearance from the corresponding pin. The smaller the clearance fit between the corresponding hole and the pin, the higher the accuracy of the parking lock during operation.

[0018] According to a preferred embodiment of the invention, the two plate elements are stamped from sheet metal and subjected to heat treatment. The heat treatment specifically includes hardening the plate elements. The plate elements serve as guard plates and enable a non-rigid, rather slightly spring-like suspension of the pawl within the transmission housing, thereby buffering force peaks and reducing the load on the support components within the housing.

[0019] Preferably, the operating unit is spatially housed between a first side plate and a second side plate, wherein each side plate includes a hole for receiving and threading a third bolt. Thus, the two side plates are connected to the two plate elements and the transmission housing via the third bolt.

[0020] Preferably, each of the two side plates includes a guide groove for guiding the roller box. In particular, the guide wall of the roller box is at least partially engaged in the two guide grooves.

[0021] According to another preferred embodiment of the invention, the first plate element is integrally connected to the first side plate, wherein the second plate element is integrally connected to the second side plate. This integral construction of the plate elements and side plates reduces the number of components in the parking lock. The original material used for the integral construction of the plate elements and side plates is preferably a sheet metal, which is stamped and heat-treated, particularly hardened.

[0022] In another configuration, the plate elements and side elements are manufactured independently. Therefore, rotor impacts in this configuration can be intercepted better than in a one-piece configuration. Attached Figure Description

[0023] Other improvements to the invention are illustrated in detail below, together with the description of two preferred embodiments of the invention, with reference to the accompanying drawings. Hereinafter:

[0024] Figure 1 shows a schematic perspective view illustrating the construction of a parking lock according to the invention according to a first embodiment.

[0025] Figure 2 shows a schematic perspective view illustrating the construction of the parking lock according to the invention according to the second embodiment.

[0026] Figure 3 shows another schematic perspective view of the parking lock according to the invention based on the first embodiment.

[0027] Figure 4 A schematic cross-sectional view of a parking lock according to the invention, based on a first embodiment, is shown.

[0028] Figure 5 A schematic cross-sectional view of the parking lock according to the invention, based on the first embodiment, is shown, which is a strongly simplified version. Detailed Implementation

[0029] Figure 1, Figure 3 Figure 4 and Figure 5 Figure 1 shows a first embodiment of the parking lock 1, while Figure 2 shows a second embodiment of the parking lock 1. Due to the different perspectives of the parking lock 1 in the figures, not all reference numerals are drawn in each figure.

[0030] According to Figure 1, the parking lock 1 includes a pawl 3, which is configured to cooperate with the teeth of a parking lock gear 2 (not shown in detail) of the transmission to release rotation of the parking lock gear 2 in the unlocked position and to engage with the teeth of the parking lock gear 2 in the locked position and lock rotation of the parking lock gear 2. Currently, the parking lock gear 2 is shown strongly simplified and spaced apart from the pawl 3, with the pawl 3 in the locked position in all figures. The pawl 3 can be connected via Figure 3 and... Figure 4The actuating unit 4, which is better shown in the diagram, is used for operation and is pivotally mounted at the first pin 6a about the axis of rotation 5. The actuating unit 4 is spatially housed between the first side plate 13a and the second side plate 13b. In addition, two spacer sleeves 16a, 16b are disposed between the two side plates and housed in the side plates.

[0031] The parking lock 1 includes a first plate element 7a and a second plate element 7b, which are configured to absorb force when the pawl 3 engages with the teeth of the parking lock gear 2. The two plate elements 7a and 7b are made of sheet metal by stamping and are heat-treated, particularly hardened. In addition to the first pin 6a, the parking lock also includes a second pin 6b and a third pin 6c, which are configured to house the parking lock within the transmission housing 9.

[0032] The parking lock 1 is supported in the transmission housing 9. Figure 5 As shown in the diagram. A first pin 6a is received in corresponding holes 8a, 8b at each of the two plate elements 7a, 7b. A second pin 6b is received in corresponding holes 8c, 8d at each of the two plate elements 7a, 7b. A third pin 6c is received in corresponding holes 8e, 8f at each of the two plate elements 7a, 7b. The second pin 6b and the third pin 6c support the two plate elements 7a, 7b and further support the entire parking lock 1 at the transmission housing 9. Currently, the housing 9 is constructed in multiple parts and includes four support portions 18 for receiving the second and third pins 6b, 6c. The two side plates 13a, 13b respectively include holes 8g, 8h for receiving and threading the third pin 6c. The parking lock 1 can be pre-installed into the transmission housing 9 and is particularly easy to install.

[0033] Since the first pin 6a, which houses the pawl 3, is not directly supported at the transmission housing 9, but is indirectly supported at the transmission housing 9 via two plate elements 7a, 7b and the second and third pins 6b, 6c, the force generated when the pawl 3 engages with the teeth of the parking lock gear 2 is distributed such that a small portion of the rotor impact reaches the four support points 18 of the second and third pins at the housing 9.

[0034] Figure 2 shows an alternative embodiment of the parking lock 1, wherein, according to Figure 2, the first plate element 7a is integrally connected to the first side plate 13a, and wherein the second plate element 7b is integrally connected to the second side plate 13b.

[0035] As can be clearly seen in Figures 1 and 3, a tension spring 12 is provided at the pawl 3 to reset the pawl 3 to the unlocked position. The tension spring 12 rests against the pawl 3 and the first plate element 7a.

[0036] According to Figure 3 and Figure 4 The operating unit 4 includes a roller box 4g, a guide rod 10, and a spring element 11. The roller box 4g abuts against the pawl 3 and can move axially in the longitudinal direction of the guide rod 10 to operate the pawl 3. The roller box 4g includes first and second rollers 4a and 4b, a roller rail wall 4c, two side walls 4d and 4e for receiving and supporting the two rollers 4a and 4b, a guide wall 4h, and a support wall 4f effectively connected to the guide rod 10. The two side plates 13a and 13b respectively include guide grooves 14a and 14b for guiding the roller box 4g, and in particular for guiding and receiving the guide wall 4h.

[0037] according to Figure 4 The first roller 4a abuts against the roller rail wall 4c, and the second roller 4b abuts against the pawl 3. Furthermore, the two rollers 4a and 4b also abut against each other. Stop surfaces 15 are formed at the two plate elements 7a and 7b, respectively, for the abutment of the roller box 4g, and particularly for the abutment of the corresponding side walls 4e and 4f in the unlocked position. Currently, the roller box 4g is shown in the locked position. The second pin 6b and the third pin 6c are respectively arranged parallel to the axis of the first pin 6a, wherein the first pin 6a is spatially positioned between the second pin 6b and the third pin 6c. The guide rod 10 is axially movably accommodated in the receiving element 17, which connects the two side plates 13a and 13b to the two plate elements 7a and 7b. The spring element 11 is axially supported on the receiving element 17 and the support wall 4f.

[0038] List of reference numerals

[0039] 1 Parking lock

[0040] 2 Parking lock gear

[0041] 3. Claws

[0042] 4. Control Unit

[0043] 4a First Roller

[0044] 4b Second Roller

[0045] 4c roller wall

[0046] 4D sidewall

[0047] 4e sidewall

[0048] 4f Support Wall

[0049] 4g roller box

[0050] 4h guide wall

[0051] 5. Rotation axis

[0052] 6a First bolt pin

[0053] 6b Second bolt pin

[0054] 6c Third bolt pin

[0055] 7a First board component

[0056] 7b Second board components

[0057] 8a-8h holes

[0058] 9. Shell

[0059] 10 Guide rods

[0060] 11 Spring elements

[0061] 12 tension springs

[0062] 13a First side plate

[0063] 13b Second side plate

[0064] 14a, 14b guide grooves

[0065] 15 stops

[0066] 16a, 16b spacer sleeves

[0067] 17. Retaining element

[0068] 18 Supporting parts

Claims

1. A parking lock (1) for a transmission of a motor vehicle, the transmission having a parking locking gear (2), the parking lock comprising: A pawl (3) is configured to cooperate with the teeth of the parking lock gear (2) to release rotation of the parking lock gear (2) in the unlocked position and to engage with the teeth of the parking lock gear (2) in the locked position and lock rotation of the parking lock gear (2), wherein the pawl (3) is operable via an operating unit (4) and is pivotally mounted at the first pin (6a) about a rotation axis (5). A first plate element (7a) and a second plate element (7b), the first plate element and the second plate element constituting a force absorber when the pawl (3) engages with the teeth of the parking lock gear (2), wherein a first pin (6a) is received at each of the first plate element (7a) and the second plate element (7b), and A second pin (6b) and a third pin (6c) are respectively received in holes at each of the first plate element (7a) and the second plate element (7b) and constitute a means for supporting the first plate element (7a) and the second plate element (7b) at the housing (9) of the transmission, wherein the first pin (6a) is spatially disposed between the second pin (6b) and the third pin (6c); At least the operating unit (4) is spatially housed between a first side plate (13a) and a second side plate (13b), the first side plate (13a) and the second side plate (13b) respectively including holes for receiving and threading the third bolt (6c), and independent of the first plate element and the second plate element.

2. The parking lock (1) according to claim 1. Its features are, The operating unit (4) includes a roller box (4g), a guide rod (10) and a spring element (11), wherein the roller box (4g) is abutted against the pawl (3) and is axially movable in the longitudinal direction of the guide rod (10) to operate the pawl (3).

3. The parking lock (1) according to claim 2. Its features are, The roller box (4g) includes a first roller (4a) and a second roller (4b), a roller rail wall (4c), two side walls (4d, 4e) for receiving and supporting the first roller (4a) and the second roller (4b), and a support wall (4f) effectively connected to the guide rod (10), wherein the first roller (4a) abuts against the roller rail wall (4c), and wherein the second roller (4b) abuts against the pawl (3).

4. The parking lock (1) according to claim 2 or 3. Its features are, Stop surfaces (15) are respectively formed at the first plate element (7a) and the second plate element (7b) for abutting against the roller box (4g) in the unlocked position.

5. The parking lock (1) according to claim 1. Its features are, A tension spring (12) is provided at the pawl (3) for resetting the pawl (3) to the unlocked position, wherein the tension spring (12) is at least abutting the pawl (3) and at least one of the first plate element (7a) and the second plate element (7b).

6. The parking lock (1) according to claim 1. Its features are, The second pin (6b) and the third pin (6c) are respectively arranged parallel to the axis of the first pin (6a), wherein the first pin (6a) is spatially disposed between the second pin (6b) and the third pin (6c).

7. The parking lock (1) according to claim 1. Its features are, The first plate element (7a) and the second plate element (7b) are made by stamping metal plates and undergoing heat treatment.

8. The parking lock (1) according to claim 1. Its features are, The first plate element (7a) is manufactured independently of the first side plate (13a) and connected to the first side plate, and the second plate element (7b) is manufactured independently of the second side plate (13b) and connected to the second side plate.

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