Parking lock

Abstract

The invention relates to a parking lock (1), comprising: a pawl (2), which is lockable in a parking lock wheel (3) in a locked position and is disengaged from the parking lock wheel (3) in an unlocked position; a pawl pin (4), on which the pawl (2) is mounted; an actuation element (6), which is preloaded by a spring (5) and by means of which the pawl (2) is movable into the locked position; and two side plates (7, 8), which surround the pawl (2) on the sides and each have a pin feedthrough (14) for the pawl pin (4). A support element (17) is fastened in the side plates (7, 8), forms together therewith a guide for the actuation element (6), and is fastened on the side plates (7, 8) on the spring side exclusively outside the movement path of the actuation element (6), as viewed in the actuation direction (12).

Description

[0001] Parking lock

[0002] The invention relates to a parking lock, comprising a pawl which can be locked in a parking lock gear in a locked position and is disengaged from the parking lock gear in an unlocked position, a pawl bolt on which the pawl is mounted, an actuating element which can be preloaded by a spring and is movable in an actuating direction and by means of which the pawl can be moved into the locked position, and two side plates which laterally enclose the pawl and each have a passage for the pawl bolt.

[0003] The parking lock of an automatic transmission of a motor vehicle known from DE 101 44 063 A1 has a locking ring with locking recesses arranged on a transmission shaft. By means of a pivoting selector lever and a linkage articulated thereto, a pawl is engaged with the locking recesses when the device is in the locked state. The linkage has rollers at its end, a second roller of which guides the linkage in an L-shaped guide plate. The guide plate is fastened in the housing of the automatic transmission. The second roller rolls on the guide plate during a longitudinal movement of the linkage. The guide plate comprises a side wall and a horizontal wall. The horizontal wall of the guide plate has elongated holes. The side wall of the guide plate is a separate component and has crenellated projections on one edge.These projections are adapted in terms of their dimensions to the elongated holes of the horizontal wall and can engage in the openings of the horizontal wall by means of a press fit.

[0004] Parking locks according to DE 10 2018 221 913 A1 or DE 101 44 058 A1 are mounted with a pawl and an actuating unit that is fixed to the transmission housing. The parking lock gear, located on the drivetrain, can be supported on a transmission housing via the pawl. The different mounting reference points result in tolerances that must be compensated for. In particular, dimensional fluctuations occur due to manufacturing processes between the centering holes in the housing and the contact surface of the actuating unit that moves the pawl. Therefore, adjustments must always be made when installing the parking lock to ensure the exact position of the pawl in relation to the parking lock gear.Although it is conceivable to shift the adjustment work from the parking lock gear-pawl interface to the pawl-actuating mechanism interface of the pawl, for example an electric motor, this has the disadvantage that the parking lock with its actuators cannot be provided as a prefabricated module, which in turn increases the assembly effort.

[0005] DE 10 2018 131 263 B4 proposes a movable plate that can tilt and thus compensate for manufacturing tolerances. Due to the load introduction in the pawl contact and the load discharge at the gearbox housing-plate contact at two non-opposite contact points of the locking element, the locking element can tilt until the two contact force vectors meet again on the center axis of the locking element. It has been found that this type of tolerance compensation is not sufficient in every case. Due to the usual guidance of the locking element on a guide rod and the insufficient degree of freedom between them, the angle compensation cannot be fully implemented. Consequently, the locking element is supported on the guide rod, load is introduced, and the guide rod bends. This leads to significant limitations in the function of the parking lock.

[0006] Further parking locks are known from EP 3 620 688 A1, CN 110 878 834 A and CN 211 820 708 U.

[0007] Object of the invention

[0008] The object of the present invention is to improve a parking lock and enable the same functionality with fewer components. This object is achieved by a parking lock with the features of claim 1.

[0009] The parking lock has a support element for the actuating element. The support element forms contact with the actuating element and thus guides it. Viewed in the actuating direction, i.e., the direction in which the actuating element is movable, it is attached to the side plates on the spring side, exclusively outside the travel path of the actuating element. The support element held in this way allows for free access to the parking lock from the side, which simplifies installation and creates space into which a pivoting actuator can also be installed.

[0010] In one embodiment of the invention, the support element forms a three-point guide with the guide through the side plates. This prevents the system from being over-determined, and the actuating element from lifting off the side plates, for example, when releasing the parking lock, is prevented. Preferably, the contacts of the actuating element and the support element are arranged opposite those of the side plates in cross-section, such that the contacts form an isosceles triangle.

[0011] The actuating element can be guided on the side plates. This means that, viewed in cross-section, unlike a guide between the side plates, the contact points form an angle of other than 180° with the center of gravity of the actuating element. The side plates therefore do not hold the actuating element between them, but form a support. This means that the side plates alone can assume a guiding function transverse to the direction of actuation, eliminating the need for additional components such as cross members or a guide rod for the actuating element. The side plates guide the actuating element as a locking body for the pawl when moving from the unlocked position NP to the locked position P, preventing any uncontrolled contact. In addition, this allows the actuating element to be freely accessible from the side above the support surface, which facilitates installation of the parking lock.For example, the actuating element can be easily placed on the side panels thanks to the cut-outs. Such a parking lock also offers the possibility of mounting it independently of the actuator that operates it.

[0012] The actuating element can be designed as a slide, but is preferably designed as a locking body that is conical at least in sections. In a further development, the entire locking body can also be designed as a cone. Such a locking body can be manufactured in one piece with little effort and, unlike a slide, does not require bearings by rollers. Alternatively, it is only conical in sections and can have a cylindrical shell section over which the locking body is preferably guided.

[0013] In a further development, the locking body can have a blind hole in which the spring is supported. Additionally or alternatively, it can have a constriction on its outer surface. This constriction minimizes the contact area with the side plates, thus reducing friction.

[0014] In a further development of the invention, the side plates form two guide rails for the actuating element. Since the force exerted on the locking pawl when inserting the actuating element does not need to be supported by the side plates, surface contact can be dispensed with due to the lack of support for high forces. A short linear contact is sufficient, which can be reduced to one or more point contacts by a conical shape, if necessary. In particular, chamfering the side plates is unnecessary, even though this could be done.

[0015] In a further development, the two side panels are designed as identical parts. This simplifies assembly because components cannot be interchanged, and reduces manufacturing costs.

[0016] Preferably, the side plates are arranged parallel to each other. The support element can be attached to the side plates, for example, by caulking. The attachment can also be such that the support element is held in the side plates with limited movement, allowing tolerance compensation.

[0017] If the support element is positioned entirely within the plane defined by the side plates, the parking lock is compact. The support element is preferably a sheet metal element arranged longitudinally parallel to the actuation direction. It can taper in the area where it is not laterally enclosed by the side plates to minimize mass.

[0018] The support element can be attached to the side plates on the spring side, viewed in the actuation direction, exclusively outside the travel path of the actuating element, and together with these, form a guide for the actuating element. This allows the side plate to have a large clearance area. This clearance area creates space for additional components. In particular, an actuator can pivot into this area, so that the parking lock can be actuated by both a linearly acting and a pivoting actuator. The travel path of the actuator is defined by the distance between the locking position P and the unlocking position NP and can be limited, in particular, by end stops.

[0019] In a further embodiment of the parking lock, a centering bolt enclosed in the spring is housed in a centering bolt bushing. The centering bolt bushing is mounted in the side plates and forms a base point for the spring, which is preferably designed as a helical compression spring. At the same time, the two side plates can support each other via the centering bolt bushing.

[0020] Further mutual support can be achieved by preferably two spacer sleeves, via which the side plates of the parking lock can be screwed to a transmission housing. For this purpose, the side elements have two screw passages. One of the screw passages can be arranged collinearly with the passage for the pawl bolt and the location where the support element is connected to the side elements, whereby the collinearity does not necessarily have to refer to the centers of the passages. Such side elements are compact.

[0021] The parking lock has defined end positions in the form of end stops for switching from P to NP. In a further development of the invention, at least one end stop is integrated into one of the side plates. This eliminates the need for a separate component, and the tolerance chain is shortened.

[0022] In one embodiment of the invention, both side plates together form an end stop, so that the actuating element is evenly supported. Preferably, both side plates each have two end stops, namely the end stop at P and the end stop at NP. Thus, the entire travel path of the actuating element is predetermined by the side plates, so that both end positions are clearly defined and have a short tolerance range.

[0023] One of the end stops, the actuating element or the side plates, can have a spherical shape. This ensures that even in the event of a slight tilt of the actuating element, a perpendicular impact with the end stop is possible.

[0024] The pawl pin forms an axis around which the pawl can rotate. It can be made of solid material or formed as a hollow cylinder. It is preferably manufactured separately from the pawl and the side plates.

[0025] A return spring for the pawl may be arranged on the pawl pin, with one end of the return spring being attached to the pawl and the other end of the spring being attached to the side plate.

[0026] The pawl is pivotable about the rotational axis of the pawl pin. It forms a pawl movable about this axis with a locking tooth at the end facing away from the rotational axis, by means of which the pawl can be positively locked into a tooth profile arranged on the parking lock gear. On the side radially facing away from the locking tooth on the parking lock gear, the pawl has a pawl back with a pawl profile, which is acted upon by the actuating element when the parking lock is engaged. The pawl profile can form a profile in the narrower sense, that is, it is designed as a profile mountain. In one variant, the pawl profile is a flat surface with a raised portion, so that a positive connection is also present at the pawl back in the locked position.

[0027] The actuation direction is defined by the direction of movement of the actuating element and preferably runs along a straight line. The side plates are preferably stamped and made of sheet metal as a single piece. The parking lock can have additional housing components that, together with the side plates, form a parking lock housing.

[0028] The parking lock can be provided for a vehicle, in particular a motor vehicle. The vehicle can be a hybrid vehicle or an electric vehicle. The vehicle can have a drivetrain with a transmission. The transmission can be installed in an electric axle. The transmission can be a dedicated hybrid transmission. The transmission can be an automatic transmission.

[0029] Further advantages and advantageous embodiments of the invention emerge from the description of the figures and the illustrations.

[0030] Description of the drawings

[0031] The invention is described below with reference to the drawings, which show in detail:

[0032] Figure 1 is a perspective view of a parking lock according to the invention with a parking lock gear on a transmission shaft,

[0033] Figure 2 shows the parking lock with the parking lock gear and the gear shaft from Figure 1 in a top view, Figure 3 shows an enlarged view of detail III of the parking lock from Figure 2,

[0034] Figure 4 is an exploded view of the parking lock with the parking lock gear and the gear shaft according to Figure 1,

[0035] Figure 5 shows the parking lock with the parking lock gear and the gear shaft according to Figure 1 in a side view in the locked position,

[0036] Figure 6 shows the parking lock with the parking lock gear and the gear shaft according to Figure 1 in a side view in the unlocked position and

[0037] Figure 7 shows an enlarged view of a side plate of the parking lock according to Figure 1.

[0038] Figure 1 shows a parking lock unit 21, which is formed from a parking lock 1, an actuator tappet 22 (shown only schematically) of an actuator not shown in detail, and a parking lock gear 3. The parking lock 1 has a pawl 2 that can be rotated about a rotation axis 30. When the pawl 2 is rotated, a ratchet tooth 23 formed integrally with it moves as a locking tooth essentially in the radial direction with respect to a transmission shaft 24. The parking lock 1 is intended for installation in a vehicle transmission of a motor vehicle and causes the parking lock gear 3, which is connected in a rotationally fixed manner to the transmission shaft 24, to be locked. For this purpose, the parking lock gear 3 has a locking toothing 29 arranged on its outer circumference, into which the pawl tooth 23 positively locks when the parking lock is in the locked position. In the unlocked position, the ratchet tooth 23 and the locking teeth 29 are disengaged.

[0039] The pawl 2 is held by a return spring 28, which prevents the pawl from inadvertently locking against the parking lock gear 3 due to gravity when unloaded. The return spring 28 is designed as a shaped spring and is suspended from the pawl 2 with one spring end. It encloses the pawl pin 4 with several coils and is supported with the other spring end in spring recesses 27 (Figure 7) that are incorporated in the side plates 7, 8.

[0040] The parking lock 1 has an actuating element 6 which can be preloaded by a spring 5, so that the parking lock 1 can be locked even in the event of a malfunction of the actuator by displacing the actuating element 6 in such a way that it brings the locking pawl 2 into the locking position or, in the case of a tooth-on-tooth position of the pawl tooth 23 with the locking toothing 29, at least preloads it in such a way that a slight movement of the parking lock gear 3 causes a locking.

[0041] The spring 5 encloses a centering pin 9, which prevents the spring 5 from buckling. It is secured in a centering pin bushing 10, which is designed as a perforated sheet metal plate. The centering pin bushing 10, in turn, is secured, preferably caulked, in receptacles 11 in the side plates 7, 8. The spring 5 rests on a blind hole 35 on the actuating element 6.

[0042] The parking lock 1 further comprises a first side plate 7 and a second side plate 8, which are arranged parallel to one another as housing walls. Both side plates 7, 8 are spaced apart from one another by several, in this case two, spacer sleeves 33. For this purpose, the two side plates 7, 8 have sleeve recesses 13, in which the spacer sleeves 33 are received. These have a stepped outer contour with an inner cylindrical section 15 that has a larger outer radius than the two outer cylindrical sections 16. The spacer sleeves 33 can thus position the two side plates 7, 8 relative to one another and support them against one another. Furthermore, as hollow cylinders, they allow the parking lock 1 to be attached to the transmission (not shown) by forming sleeves for screws 32. Together with the center bolt bushing 10, they ensure the rigidity of the side plates 7, 8 as a parking lock housing.The side plates 7, 8 each have a bolt passage 14 for the pawl bolt 4.

[0043] The side plates 7, 8 are designed as equal parts in this case. The actuating element 6 is guided by two guide edges 25 of the side plates 7, 8. The actuating element 6 can slide linearly along these in an actuating direction 12, which is the direction of movement of the actuating element, so that they form guide rails. The possible movement is limited by two end stops 37, 38, which determine the possible travel path 36 for the actuating element 6. Both end stops 37, 38 are each integrated into the side plates 7, 8. In this case, the second end stop 38, on the unlocking position side, is spherical to ensure that the introduced forces are supported as vertically as possible, even in the event of slight tilting of the actuating element or due to manufacturing inaccuracies.By integrating the end stops 37, 38 into the sheet metal parts 7, 8, separate end stops are eliminated. On the one hand, this creates a free space 39 that allows the side plates 7, 8 to be cut free, thus permitting the actuating element to be constructed as a short and accessible cone. Due to this open design, the parking lock can be actuated not only by a linearly movable actuator tappet 22, but also by an actuator (not shown) that performs a pivoting movement. The free space in the thus reduced side plates 7, 8 further saves mass and installation space.

[0044] A support element 17 is arranged radially opposite the actuating element 6 with respect to the locking pawl 2. The support element 17 preferably allows both a support of the parking lock torques in the transmission housing and a further guide for the actuating element 6. Together with the guide edges

[0045] 25, the actuating element is thus seen in cross-section at three support points

[0046] 26, so that a safe, neither over- nor under-determined three-point guidance is provided.

[0047] The support element 17 is designed as a sheet metal part that is received in support element receptacles 31 of the side plates 7, 8 and is secured exclusively there. In this area of ​​its attachment, it has a greater width, corresponding to the distance formed by the spacer sleeves 33, than in its guide area 34 facing the actuating element 6.

[0048] List of reference symbols

[0049] 1 parking lock

[0050] 2 pawls

[0051] 3 parking lock gear

[0052] 4 pawl bolts

[0053] 5 spring

[0054] 6 Actuating element

[0055] 7 first side panel

[0056] 8 second side panel

[0057] 9 hundredweight bolts

[0058] 10 centner bolt penetration

[0059] 11 Recording

[0060] 12 Actuation direction

[0061] 13 sleeve recesses

[0062] 14 Bolt feedthrough

[0063] 15 inner cylinder section

[0064] 16 outer cylinder section

[0065] 17 Support element

[0066] 18 Front side

[0067] 19 Shell surface

[0068] 20 Constriction

[0069] 21 Parking lock unit

[0070] 22 actuator tappets

[0071] 23 ratchet tooth

[0072] 24 Gear shaft

[0073] 25 leading edge

[0074] 26 Support point

[0075] 27 Spring recess

[0076] 28 Return spring

[0077] 29 Locking teeth 30 Rotation axis

[0078] 31 Support element holder

[0079] 32 screw

[0080] 33 Spacer sleeve 34 Guide area

[0081] 35 blind hole

[0082] 36 travel path

[0083] 37 first end stop

[0084] 38 second end stop 39 space

Claims

Patent claims 1 . Parking lock (1 ), comprising - a pawl (2) which, in a locking position, can be locked in a parking lock gear (3) and, in an unlocking position, is disengaged from the parking lock gear (3), - a pawl bolt (4) on which the pawl (2) is mounted, - an actuating element (6) which can be pretensioned by a spring (5) and is movable in an actuating direction (12), by means of which the locking pawl (2) can be moved into the locking position, - two side plates (7, 8) which laterally enclose the pawl (2) and each have a bolt passage (14) for the pawl bolt (4), - a support element (17) which is fastened in the side plates (7, 8), - characterized in that the support element (17), seen in the actuating direction (12), is fastened on the spring side to the side plates (7, 8) exclusively outside the travel path of the actuating element (6) and forms a guide for the actuating element (6) with these.

2. Parking lock according to claim 1, characterized in that the actuating element (6) is at least partially conical or cylindrical.

3. Parking lock according to claim 1 or 2, characterized in that the support element (17) with the side plates (7, 8) forms a three-point guide for the actuating element (6).

4. Parking lock according to one of the preceding claims, characterized in that the parking lock (1) has a pivotable actuator by which the spring (5) can be pretensioned via the actuating element (6).

5. Parking lock according to one of the preceding claims, characterized in that the side plates (7, 8) are arranged parallel to one another and a support element (17) fastened to them is arranged within the planes spanned by the side plates (7, 8) and in its longitudinal direction parallel to these.

6. Parking lock according to one of the preceding claims, characterized in that the side elements (7, 8) have two sleeve recesses (13), one of the sleeve recesses (13) being arranged collinearly with the bolt passage (14) for the pawl bolt (4) and the fastening of the support element (17).

7. Parking lock according to one of the preceding claims, characterized in that the actuating element (6) has end faces (18) and a cylindrical outer surface (19) which has a constriction (20) spaced from the end faces (18).

8. Parking lock according to one of the preceding claims, characterized in that the side plates (7, 8) are designed as identical parts.

9. Parking lock according to one of the preceding claims, characterized in that the side plates (7, 8) have an end stop (37, 38) for the actuating element (6).

10. Parking lock according to claim 9, characterized in that the end stops (37, 38) are designed as spherical sheet metal edges of the side plates (7, 8).

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