CN215567882U - Parking device and transmission - Google Patents

Abstract

The utility model discloses a parking device which comprises a ratchet wheel, a pawl, a locking mechanism and a driving mechanism, wherein the pawl is rotationally connected to a shell of a transmission and can be switched back and forth between an unlocking position and a locking position; the locking mechanism comprises a cam, when the transmission is in a P gear, the driving mechanism drives the cam to rotate by a preset locking angle along a first rotating direction, the pawl is driven to rotate from an unlocking position to a locking position through the contact of the cam and the bearing part, and the cam and the bearing part are matched involute gears. The utility model also discloses a transmission comprising the parking device.

Description

Parking device and transmission

Technical Field

The utility model relates to the technical field of automobile transmissions, in particular to a parking device and a transmission.

Background

When the automobile stops on a horizontal road, a driver can brake the whole automobile only by pulling the hand brake. However, if the vehicle is parked on a steep slope, the handbrake alone may fail. Ordinary manual transmissions rely on engine reverse to ensure that the vehicle does not slip by engaging a gear, but for electric vehicles, measures must be taken to prevent accidents, so a parking device is required to brake the transmission system.

The parking device is a safety device for preventing the vehicle from sliding accidentally, which acts on the vehicle speed changer to lock the transmission system of the speed changer, so that the vehicle can be reliably stopped at a certain position even on a slope without time limitation. Therefore, the parking device is widely used in automatic transmissions as well as transmissions driven by a motor.

Currently, the following problems exist:

the ratchet wheel of the parking device is arranged on the differential or the intermediate shaft, the torque borne by the parking device is large, the allowance of the parking device is insufficient in strength, and the pawl is broken under certain special working conditions; some parking devices have the disadvantages of complex structure, difficult installation and positioning, great control difficulty and high machining precision requirement; the friction force is large when the gear P is switched, noise and vibration are generated, and the NVH performance of the whole vehicle is influenced.

The foregoing description is provided for general background information and is not admitted to be prior art.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a parking device and a transmission with small friction force when switching P gear.

The utility model provides a parking device which comprises a ratchet wheel, a pawl, a locking mechanism and a driving mechanism, wherein the pawl is rotationally connected to a shell of a transmission and can be switched back and forth between an unlocking position and a locking position; the locking mechanism comprises a cam, when the transmission is in a P gear, the driving mechanism drives the cam to rotate by a preset locking angle along a first rotating direction, the pawl is driven to rotate from an unlocking position to a locking position through the contact of the cam and the bearing part, and the cam and the bearing part are matched involute gears.

Further, the cam comprises a base circle part and a convex part which protrudes outwards along the radial direction of the base circle part, the top surface of the convex part comprises a first arc surface, a second arc surface and a transition curved surface connected between the first arc surface and the second arc surface, the base circle part, the first arc surface and the second arc surface are coaxial, and the radius of the first arc surface is smaller than that of the second arc surface; in the unlocking position, the first arc surface is abutted with the pressure bearing part; in the locking position, the second arc surface abuts against the pressure-receiving portion.

Furthermore, the first arc surface, the transition curved surface and the second arc surface form a first gear tooth together, the bearing part forms a second gear tooth, and the first gear tooth and the second gear tooth are matched involute gears.

Furthermore, the locking mechanism further comprises a cam shaft, a limiting block and an energy storage component, the limiting block is fixed on the cam shaft, the cam is rotatably sleeved on the cam shaft, and the energy storage component is connected between the limiting block and the cam;

when the transmission is in a P gear, the driving mechanism drives the cam shaft to rotate by a preset locking angle along a first rotating direction, the cam shaft is driven to rotate along the first rotating direction by the rotation of the cam shaft through the limiting block and the energy storage part, and the pawl is driven to rotate from an unlocking position to a locking position by the contact of the cam and the pressure bearing part;

after the camshaft rotates by the preset locking angle, the pawl directly reaches a locking position from an unlocking position or reaches a false locking position from the unlocking position; in the false locking position, the pawl interferes with the tooth crest of the ratchet wheel and cannot be clamped into the clamping groove of the ratchet wheel, the energy storage component can store energy in a time period from the moment that the pawl is just contacted with the tooth crest of the ratchet wheel to the moment that the cam shaft finishes rotating the preset locking angle, and when the ratchet wheel rotates due to the rotation of the wheel, the cam pushes the pawl to rotate to the locking position under the acting force of the energy storage component until the pawl reaches the locking position.

Furthermore, the energy storage part is a first torsion spring, the first torsion spring is sleeved on the cam shaft in a clearance mode, one end of the first torsion spring is connected to the cam, and the other end of the first torsion spring is connected to the limiting block.

The pawl locking device further comprises a pawl returning component, and the acting force exerted on the pawl by the pawl returning component enables the pawl to always have the tendency of rotating towards the unlocking position; when the transmission releases the P gear, the driving mechanism drives the cam shaft to rotate by the preset locking angle along a second rotating direction opposite to the first rotating direction, the cam shaft rotates by the aid of the limiting block to drive the cam to rotate along the second rotating direction, and the pawl returns to the unlocking position from the locking position by the aid of the pawl returning component.

Furthermore, the pawl is rotatably connected to a shell of the transmission through a rotating shaft, the pawl return component is a second torsion spring, the second torsion spring is sleeved on the rotating shaft in a clearance mode, one end of the second torsion spring is connected to the pawl, and the other end of the second torsion spring is connected to the shell of the transmission.

Further, the ratchet wheel is relatively fixedly arranged on the input shaft of the transmission.

Further, the drive mechanism is integrally provided outside a housing of the transmission; the driving mechanism comprises a motor, a worm and gear speed reducing mechanism and an angle sensor, the worm and gear speed reducing mechanism comprises a worm wheel and a worm which are meshed, an output shaft of the motor is coaxially connected with or integrally formed with the worm, and one end of the cam shaft is connected to the center of the worm wheel; the angle sensor is used for detecting the rotation angle of an output shaft of the motor, the rotation angle of the worm or the rotation angle of the worm wheel, so that the rotation angle of the cam shaft is obtained.

The utility model also provides a transmission comprising the parking device as described above.

According to the parking device provided by the utility model, the cam and the pressure bearing part are designed into the involute gear, so that the friction force generated when the cam is contacted with the pawl is reduced, the pawl is stably and quickly switched between the parking position and the unlocking position, the vibration and the noise are reduced, and the NVH performance of the whole vehicle is improved. And the ratchet wheel is arranged on the input shaft of the transmission, so that the torque applied to the parking device is small, and the service life of the pawl is obviously prolonged. The energy storage component is used for realizing the delayed locking function, the locking mechanism is simple in structure, few in parts, small in accumulated tolerance of a size chain, and more accurate in pawl position during parking, so that the parking is smooth.

Drawings

FIG. 1 is a schematic structural diagram of a parking apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a pawl in the parking device of FIG. 1;

fig. 3 is a schematic structural view of a cam in the parking apparatus shown in fig. 1.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model.

Referring to fig. 1 to 3, a parking device according to an embodiment of the present invention is applied to an automobile, and includes a ratchet 10, a pawl 20, a rotating shaft 30, a pawl returning member 40, a locking mechanism 50 and a driving mechanism 60, wherein the pawl 20 is rotatably connected to a housing (not shown) of a transmission through the rotating shaft 30 and can be switched between an unlocking position and a locking position, and the ratchet 10 is relatively fixedly disposed on an input shaft or an output shaft of the transmission.

In the present embodiment, the ratchet 10 is fixed to an input shaft (not shown) of the transmission, so that the torque applied to the parking device is small, and the service life of the pawl is remarkably prolonged. The ratchet 10 may be relatively fixedly disposed on the input shaft of the transmission by way of spline connection so that the ratchet 10 rotates integrally with the input shaft of the transmission, i.e., the ratchet 10 has an internally splined bore 11 and the input shaft of the transmission is provided with external splines. The input shaft can be locked by the locking ratchet wheel 10, for a transmission of a single-gear electric vehicle, the input shaft and the output shaft are in hard connection through a gear, and the parking of the vehicle can be realized by the locking ratchet wheel 10.

Referring to fig. 2, the pawl 20 includes a pawl body 21 and a second connecting portion 22 extending outward away from the rotating shaft 30, the pawl body 21 is rotatably connected to the casing of the transmission through the rotating shaft 30, a latch 211 is formed at one end of the pawl body 21, and a pressing portion 212 is formed at one side of the latch 211 opposite to the ratchet 10. In the locking position, the latch 211 is latched into the tooth slot of the ratchet 10; in the unlocking position, the latch 211 is disengaged from the tooth slot of the ratchet 10; the force exerted by the pawl return member 4 on the pawl 2 causes the pawl 20 to always have a tendency to rotate towards the unlocked position.

The locking mechanism 50 comprises a cam shaft 51, a limiting block 52, a cam 53 and an energy storage part 54, wherein the limiting block 52 is fixed on the cam shaft 51, the cam 53 is rotatably sleeved on the cam shaft 51, and the energy storage part 54 is connected between the limiting block 52 and the cam 53. The cam 53 is located between the stopper 52 and the driving mechanism 60, and the stopper 52 is used for limiting the axial movement of the cam 53 on the cam shaft 51.

When the transmission is in the P gear, the driving mechanism 60 drives the cam shaft 51 to rotate by a preset locking angle in the first rotation direction, the rotation of the cam shaft 51 drives the cam 53 to rotate in the first rotation direction through the limiting block 52 and the energy storage part 54, and the contact between the cam 53 and the pressure bearing part 212 drives the pawl 20 to rotate from the unlocking position to the locking position.

After the camshaft 51 is rotated by the preset locking angle, the pawl 20 reaches the locked position directly from the unlocked position or the pawl 20 reaches the false locked position from the unlocked position. In the false locking position, the pawl 20 interferes with the tooth top of the ratchet 10 and cannot be clamped into the clamping groove of the ratchet 10, and the energy storage part 54 can store energy in the time period from the beginning of the contact between the pawl 20 and the tooth top of the ratchet 10 to the completion of the rotation of the cam shaft 51 by the preset locking angle. When the ratchet 10 is rotated by the rotation of the wheel (for example, when the automobile is parked on a slope), the cam 53 pushes the pawl 20 to rotate to the locking position under the force of the energy accumulating part 54 until the pawl 20 reaches the locking position.

That is, locking is in two cases, one is just locking, and during the rotation of pawl 20, there is no part interfering with the rotation of pawl 20, and pawl 20 rotates until pawl tooth 211 engages the tooth slot of ratchet 10. The other is that, in the rotation process of the pawl 20, the tooth crest of the ratchet wheel 10 firstly contacts and interferes with the latch tooth 211 of the pawl 20, so that the latch tooth 211 cannot be immediately latched into the tooth space of the ratchet wheel 10, at this time, when the automobile slides, the wheel rotates to drive the output shaft and the input shaft of the transmission to rotate, and then the ratchet wheel 20 rotates along with the rotation until the latch tooth 211 of the pawl 20 is completely latched into the tooth space of the ratchet wheel 10. Thus, when the automobile is placed on a slope, the limp-home locking is realized without an additional locking structure, and the delayed locking is realized by a simple structure.

When the transmission releases the P gear, the driving mechanism 60 drives the cam shaft 53 to rotate by a preset locking angle in a second rotating direction opposite to the first rotating direction, the cam shaft 51 rotates to drive the cam 53 to rotate in the second rotating direction through the limiting block 52, and the pawl 20 returns to the unlocking position from the locking position by means of the pawl returning part 4, so that the P gear unlocking is realized.

Referring to fig. 3, the cam 53 includes a base circular portion 531, a protruding portion 532 protruding outward along a radial direction of the base circular portion 531, and a first connecting portion 533, a top surface of the protruding portion 532 includes a first arc surface 5321, a second arc surface 5322, and a transition curved surface 5323 connected between the first arc surface 5321 and the second arc surface 5322, the cam shaft 53, the base circular portion 531, the first arc surface 5321, and the second arc surface 5322 are coaxial, and a radius of the first arc surface 5321 is smaller than a radius of the second arc surface 5322.

In the unlocking position, the first arc surface 5321 abuts against the pressure bearing part 212; in the lock position, the second arc surface 5322 abuts against the pressure receiving portion 212. Since the radius of the first arc surface 5321 is smaller than the radius of the second arc surface 5322, when the first arc surface 5321 abuts against the pressure receiving portion 212, the teeth of the pawl 20 are disengaged from the tooth grooves of the ratchet 10. When the second arc surface 5322 abuts against the pressure receiving portion 212, the teeth of the pawl 20 are engaged with the teeth grooves of the ratchet 10.

The first circular arc surface 5321, the second circular arc surface 5322 and the transition curved surface 5323 form a first gear tooth together, the pressure-bearing portion 212 forms a second gear tooth, and the first gear tooth and the second gear tooth are matched involute gears. When the locking mechanism 50 rotates, the first gear tooth and the second gear tooth always keep the unchanged transmission ratio, the friction force when the cam 53 is contacted with the pawl 20 is reduced, the speed of the pawl 20 during the switching of the parking and unlocking positions is improved, the Vibration and the Noise are reduced, and the NVH (Noise, Vibration and Harshness) performance of the whole vehicle is improved.

In this embodiment, the energy storage component 54 is a first torsion spring, the first torsion spring is sleeved on the cam shaft 51 with a gap, one end of the first torsion spring is connected to the first connecting portion 533, and the other end of the first torsion spring is connected to the limiting block 52. The first connecting portion 533 is used to increase the arm of the first torsion spring, so that the first torsion spring can more smoothly drive the cam 53 to rotate on the cam shaft 51. The first torsion spring is preloaded during assembly so that the cam 53 can rotate rapidly with the cam shaft 51 when it begins to rotate.

When the pawl 20 is in the false locking position, the pawl 20 interferes with the tooth top of the ratchet 10 and cannot be clamped into the clamping groove of the ratchet 10, and at this time, the limit block 52 still rotates along the first selection direction along with the cam shaft 51. The end of the first torsion spring connected to the stopper 52 rotates following the stopper 52, and the end of the first torsion spring connected to the cam 53 is not changed in position due to the interference of the pawl 20 with the ratchet 10. The distance between the two ports of the first torsion spring is pulled apart, the first torsion spring accumulates elastic potential energy, and the position of the limiting block 52 is unchanged until the driving mechanism 60 rotates to the preset locking angle. When the ratchet 10 rotates due to the rotation of the wheel (for example, when the automobile is parked on a slope), the pawl 20 does not interfere with the tooth top of the ratchet 10, the first torsion spring tends to return to the initial state, and the position of one end of the first torsion spring connecting limit block 52 is unchanged, and the other end drives the cam 53 to select along the first direction under the action of elastic potential energy until the pawl 20 reaches the locking position.

In this embodiment, the pawl returning member 40 is a second torsion spring, the second torsion spring is sleeved on the rotating shaft 30 with a gap, one end of the second torsion spring is connected to the second connecting portion 22, and the other end of the first torsion spring is connected to a housing of the transmission (for example, a cylindrical hole on the housing of the transmission). Therefore, when the P gear is released, the pawl 20 is returned by the second torsion spring, so that the pawl 20 can be prevented from freely rotating when the P gear is not engaged, and the parking device is prevented from being damaged due to contact with the ratchet 10 during the running of the automobile. The elastic potential energy of the second torsion spring is smaller than that of the first torsion spring, so that the second torsion spring can realize the reset of the pawl 20, and the delayed locking function is not influenced.

In the present embodiment, the drive mechanism 60 is provided entirely outside the housing of the transmission. The driving mechanism 60 includes a motor, a worm and gear speed reducing mechanism and an angle sensor, the worm and gear speed reducing mechanism includes a worm wheel and a worm which are engaged, and the worm wheel and the worm are arranged in a casing of the speed reducing mechanism. An output shaft of the motor 60 is coaxially or integrally connected to the worm, and one end of the cam shaft 51 is connected to a center position of the worm wheel. Thus, the worm wheel rotates in synchronization with the camshaft 51. The angle sensor is used for detecting the rotation angle of the worm wheel so as to obtain the rotation angle of the camshaft (the rotation angle of the worm wheel is the rotation angle of the camshaft).

In other embodiments, the worm gear speed reducing mechanism can be replaced by other speed reducing mechanisms such as a planetary gear speed reducing mechanism and a cylindrical gear speed reducing mechanism under the premise of adding the self-locking mechanism. The angle sensor may also be used to detect the rotational angle of the motor output shaft or the rotational angle of the worm. Based on the speed ratio of the worm gear and worm speed reducing mechanism, the rotation angle of the cam shaft can be obtained through the rotation angle of the output shaft of the motor or the rotation angle of the worm.

The embodiment of the utility model also provides a transmission which comprises the parking device of the embodiment.

According to the parking device provided by the embodiment of the utility model, the cam 53 and the pressure bearing part 212 are designed into the involute gear, so that the friction force generated when the cam 53 is contacted with the pawl 20 is reduced, the pawl 20 is stably and quickly switched between the parking position and the unlocking position, the vibration and the noise are reduced, and the NVH performance of the whole vehicle is improved. By arranging the ratchet 10 on the input shaft of the transmission, the torque applied to the parking device is small, and the service life of the pawl is remarkably prolonged. The energy storage part 54 realizes a delayed locking function, and the locking mechanism 50 has a simple structure, few parts, small accumulated tolerance of a size chain, and more accurate position of the pawl 20 during parking, so that the parking is smooth.

In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.

In this document, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the purpose of clarity and convenience of description of the technical solutions, and thus, should not be construed as limiting the present invention.

As used herein, the ordinal adjectives "first", "second", etc., used to describe an element are merely to distinguish between similar elements and do not imply that the elements so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

As used herein, the meaning of "a plurality" or "a plurality" is two or more unless otherwise specified.

As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims (10)

1. The parking device is characterized by comprising a ratchet wheel, a pawl, a locking mechanism and a driving mechanism, wherein the pawl is rotationally connected to a shell of a transmission and can be switched back and forth between an unlocking position and a locking position; the locking mechanism comprises a cam, when the transmission is in a P gear, the driving mechanism drives the cam to rotate by a preset locking angle along a first rotating direction, the pawl is driven to rotate from an unlocking position to a locking position through the contact of the cam and the bearing part, and the cam and the bearing part are matched involute gears.

2. The parking device according to claim 1, wherein the cam includes a base circle portion and a protruding portion protruding outward in a radial direction of the base circle portion, a top surface of the protruding portion includes a first arc surface, a second arc surface, and a transition curved surface connected between the first arc surface and the second arc surface, the base circle portion, the first arc surface, and the second arc surface are coaxial, and a radius of the first arc surface is smaller than a radius of the second arc surface; in the unlocking position, the first arc surface is abutted with the pressure bearing part; in the locking position, the second arc surface abuts against the pressure-receiving portion.

3. The parking device according to claim 2, wherein the first arc surface, the transition curved surface and the second arc surface together form a first gear tooth, the bearing part forms a second gear tooth, and the first gear tooth and the second gear tooth are matched involute gears.

4. The parking device according to claim 1, wherein the locking mechanism further comprises a cam shaft, a limiting block and an energy storage component, the limiting block is fixed on the cam shaft, the cam is rotatably sleeved on the cam shaft, and the energy storage component is connected between the limiting block and the cam;

when the transmission is in a P gear, the driving mechanism drives the cam shaft to rotate by a preset locking angle along a first rotating direction, the cam shaft is driven to rotate along the first rotating direction by the rotation of the cam shaft through the limiting block and the energy storage part, and the pawl is driven to rotate from an unlocking position to a locking position by the contact of the cam and the pressure bearing part;

after the camshaft rotates by the preset locking angle, the pawl directly reaches a locking position from an unlocking position or reaches a false locking position from the unlocking position; in the false locking position, the pawl interferes with the tooth crest of the ratchet wheel and cannot be clamped into the clamping groove of the ratchet wheel, the energy storage component can store energy in a time period from the moment that the pawl is just contacted with the tooth crest of the ratchet wheel to the moment that the cam shaft finishes rotating the preset locking angle, and when the ratchet wheel rotates due to the rotation of the wheel, the cam pushes the pawl to rotate to the locking position under the acting force of the energy storage component until the pawl reaches the locking position.

5. The parking device according to claim 4, wherein the energy storage component is a first torsion spring, the first torsion spring is sleeved on the cam shaft in a clearance mode, one end of the first torsion spring is connected to the cam, and the other end of the first torsion spring is connected to the limiting block.

6. The parking device according to claim 4, further comprising a pawl return member, the force exerted by the pawl return member on the pawl being such that the pawl always has a tendency to rotate toward the unlocked position; when the transmission releases the P gear, the driving mechanism drives the cam shaft to rotate by the preset locking angle along a second rotating direction opposite to the first rotating direction, the cam shaft rotates by the aid of the limiting block to drive the cam to rotate along the second rotating direction, and the pawl returns to the unlocking position from the locking position by the aid of the pawl returning component.

7. The parking device according to claim 6, wherein the pawl is rotatably connected to a housing of the transmission through a rotating shaft, the pawl return member is a second torsion spring, the second torsion spring is sleeved on the rotating shaft in a clearance manner, one end of the second torsion spring is connected to the pawl, and the other end of the second torsion spring is connected to the housing of the transmission.

8. The parking device according to any one of claims 4 to 7, wherein the drive mechanism is integrally provided outside a housing of the transmission; the driving mechanism comprises a motor, a worm and gear speed reducing mechanism and an angle sensor, the worm and gear speed reducing mechanism comprises a worm wheel and a worm which are meshed, an output shaft of the motor is coaxially connected with or integrally formed with the worm, and one end of the cam shaft is connected to the center of the worm wheel; the angle sensor is used for detecting the rotation angle of an output shaft of the motor, the rotation angle of the worm or the rotation angle of the worm wheel, so that the rotation angle of the cam shaft is obtained.

9. Parking device according to claim 1, wherein the ratchet wheel is arranged relatively fixedly on the input shaft of the transmission.

10. A transmission characterized by comprising a parking device according to any one of claims 1-9.

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