A central parking system

Abstract

The application provides a central parking system, and the central parking system is miniaturized by improving the structure of the central parking system. The central parking system comprises a driving assembly, a seat, a second tooth structure, a first tooth structure and a transmission shaft in transmission connection with a transmission shaft of a vehicle motor, the second tooth structure is in rotation following with the transmission shaft, the first tooth structure is in sliding fit with the seat, the seat is a fixed end and is used for supporting the driving assembly, and the first tooth structure is driven by the driving assembly to move along the axial direction of the transmission shaft to engage with or move away from the second tooth structure. In the scheme of the application, the traditional friction braking mode of the drum brake on the circumferential side wall of the brake drum is changed, the axial engagement mode of the two tooth structures is adopted, the rotation radius of the first tooth structure is significantly reduced, the size of the seat is correspondingly reduced, and the miniaturization of the central parking system is realized.

Description

Technical Field

[0001] This invention relates to the field of vehicle braking technology, and more specifically, to a central parking system. Background Technology

[0002] A central parking system is used to brake the vehicle's power output. Common central parking systems include drum brakes. The brake drum is bolted to the brake connecting flange, which is then splined to the power output end (the gear shaft of the reducer or the drive shaft connected to the motor output). The brake backing plate is the fixed end, and components such as the brake shoes are fixed to it. During braking, the friction pads on the brake shoes contact the inner wall of the brake drum, generating friction to achieve parking. However, existing central parking systems are relatively large. Miniaturization of central parking systems has been a continuous pursuit for those skilled in the art. Summary of the Invention

[0003] The purpose of the invention is to provide a central parking system that achieves miniaturization by improving the structure of the central parking system.

[0004] To achieve the above objectives, the present invention provides a central parking system, including a drive assembly, a seat, a second tooth structure, a first tooth structure, and a drive shaft connected to a vehicle motor drive shaft. The second tooth structure rotates with the drive shaft. The first tooth structure is slidably fitted onto the seat, which is a fixed end supporting the drive assembly. Under the drive assembly, the first tooth structure moves axially along the drive shaft to engage or disengage with the second tooth structure. In this application, the traditional drum brake method of friction braking on the circumferential sidewall of the brake drum is changed. By employing two tooth structures engaging axially, the rotation radius of the first tooth structure is significantly reduced, thereby correspondingly reducing the size of the seat and achieving miniaturization of the central parking system.

[0005] Optionally, both the first tooth structure and the second tooth structure have a plurality of teeth; the tooth height of each tooth is parallel to the axis of the transmission shaft, each tooth extends radially along the transmission shaft, and is arranged circumferentially along the transmission shaft.

[0006] By setting multiple teeth that can mesh with each other along the axial direction, the number of teeth is increased, and the transmitted torque is significantly increased; this achieves an overall reduction in the size of the central parking system while also increasing the braking strength of the central parking system.

[0007] Optionally, it also includes a housing portion, in which the drive shaft and the second tooth structure are disposed, and the seat portion is fixedly connected to the housing portion; the end of the drive shaft extends axially beyond the second tooth structure and into the seat portion, thereby further reducing the axial dimension.

[0008] Optionally, the seat includes a fixedly connected inner cylinder and an outer cylinder, the inner cylinder being located inside the outer cylinder, and an annular cavity being defined between the inner cylinder and the outer cylinder. The first tooth structure includes a brake ring, which is located inside the annular cavity and slides in cooperation with the wall of the annular cavity. The annular cavity, the brake ring, and the second tooth structure are coaxially arranged.

[0009] Optionally, one end of the inner cylinder is fixed to the outer cylinder in the axial direction, and the other end extends into the shell portion and is located radially outside the drive shaft; the tooth body located in the second tooth structure is located radially on the side of the inner cylinder away from the drive shaft and is axially opposite to the annular cavity, thereby making the arrangement of the components more compact.

[0010] Optionally, the drive assembly includes an ejector and a retractor, the ejector having an ejection mode and a retraction mode; in the ejection mode, the ejector drives the first tooth structure to move toward the direction closer to the second tooth structure and drives the retractor to deform to store energy; in the retraction mode, the retractor drives the first tooth structure to move toward the direction away from the second tooth structure.

[0011] Through the coordinated action of the ejector and the springback mechanism, the first tooth structure can quickly approach and accurately align with the second tooth structure. In the ejection mode, the ejector can quickly push the first tooth structure toward the second tooth structure, ensuring that the two can mesh quickly and accurately, achieving effective braking or locking. In the retraction mode, the springback mechanism uses its stored energy to automatically drive the first tooth structure away from the second tooth structure, achieving automatic reset. At the same time, it simplifies the mechanical structure and reduces the need for external control components.

[0012] Optionally, the ejector includes a drive shaft, a cam, and an actuator motor. The drive shaft is provided with a cam. The drive shaft is arranged radially along the transmission shaft, and the cam rotates around the drive shaft. In this embodiment, the arrangement of the drive shaft radially along the transmission shaft and the movement of the first tooth structure by the cam can further reduce the space occupied by the drive assembly in the axial direction of the transmission shaft, thereby reducing the size of the central parking system.

[0013] Optionally, the cam rotates around the drive shaft. The cam has a small-diameter side and a large-diameter side. When the cam rotates from the small-diameter side to the large-diameter side, it is in the push-out condition; when it rotates back from the large-diameter side to the small-diameter side, it is in the retraction condition. Thus, when the cam rotates from the small-diameter side to the large-diameter side, its shape change converts the rotational motion into the linear motion of the push-out component. When the cam returns from the large-diameter side to the small-diameter side, the return component uses the previously stored energy to automatically drive the first tooth structure away from the second tooth structure, achieving the retraction condition. By using the rotation of the cam to drive the first tooth structure to move axially, the size of the central parking system is reduced, while also simplifying the structure.

[0014] Optionally, the cam is formed by a wedge-shaped body curling around the drive shaft. The wedge-shaped body has a large-diameter end on the large-diameter side and a small-diameter end on the small-diameter side. The small-diameter end is directly or indirectly connected to the large-diameter end, and the inner wall of the wedge-shaped body fits against the outer wall of the drive shaft. This significantly reduces the axial thrust of the drive shaft, achieving a conversion from small torque to large thrust.

[0015] Optionally, the cam has a wedge-shaped section and a constant-diameter section, the wedge-shaped body serving as the wedge-shaped section, the outer wall of the constant-diameter section being equidistant from the central axis of the drive shaft, the constant-diameter section being connected to the large-diameter end, the small-diameter end being connected to the side of the constant-diameter section away from the large-diameter end along the circumference of the drive shaft, and the outer wall of the constant-diameter section being equidistant from the rotation center of the cam; when the first tooth structure meshes with the second tooth structure, the first tooth structure abuts against the constant-diameter section; in this way, when the second tooth structure meshes with the first tooth structure, the two tooth structure components will generate a large axial thrust, which is applied to the cam's point of action (large-diameter end) through its own center and rotation center to achieve self-locking, and the drive shaft does not need to apply a large axial force to the first tooth structure to prevent the two tooth structures from separating, thereby ensuring the meshing effect.

[0016] Optionally, the brake ring includes a ring body, the ring body being provided with the teeth; a stepped structure is formed on the inner ring side of the ring body, the stepped structure including a first platform and a second platform, the first platform and the second platform being axially opposite each other; the first platform abuts against the ejector; the second platform abuts against the spring-loaded member; the outer wall of the inner cylinder, the second platform, and the inner wall of the ring body form a guide cavity, the spring-loaded member being disposed within the guide cavity; in this way, the arrangement space of the spring-loaded member can be increased, and the axially movable range of the first tooth structure can be increased.

[0017] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0019] Figure 1 This is a schematic diagram of the structure of a traditional drum brake;

[0020] Figure 2 This is a schematic diagram of the central parking system in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the second tooth structure;

[0022] Figure 4 This is a projection of the cam along the transmission shaft axis in an embodiment of the present invention;

[0023] Figure 5 yes Figure 4 Force analysis diagram;

[0024] Figure 6 This is a schematic diagram of the cam after it has been unfolded.

[0025] Figure label:

[0026] Figure 1 middle:

[0027] 1′-Brake drum; 2′-Housing; 3′-Gear shaft;

[0028] Figures 2-5 middle:

[0029] 100 - First tooth structure; 200 - Second tooth structure; 300 - Drive assembly;

[0030] 1-Actuating motor; 2-Bolt; 3-Seat; 4-Oil seal; 5-Needle roller bearing; 6-Ring body; 7-Spring; 8-Annular baffle; 9-Position sensor; 10-Drive shaft; 11-Inner cylinder; 12-Stepped structure; 13-Gear body; 14-Retaining ring; 15-Drive shaft; 16-Flange; 17-Outer cylinder; 171-Annular flange; 18-Shell; 19-Cam; 191-Upper side; 192-Lower side; 193-Large diameter end; 193a-Left side; 194-Small diameter end; 194a-Right side; 195-Wedge section; 196-Equal diameter section; H-Tooth height; P-Axial direction. Detailed Implementation

[0031] This invention provides a central parking system that achieves miniaturization by improving the structure of the central parking system.

[0032] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, Figure 1 This is a schematic diagram of a traditional drum brake. When the drum brake is activated, the brake shoes are pushed outward (i.e., the radial direction of the brake drum 1' is away from the center of the brake drum 1'), causing the friction pads on them to fit tightly against the inner surface of the rotating brake drum 1'. In this process, the friction pads rub against the brake drum 1' radially. Specifically, the brake drum 1' is cylindrical, and its inner surface (i.e., the circumferential sidewall) is rough to generate sufficient friction with the friction pads on the brake shoes. The brake shoes are pushed outward, causing the friction pads on them to press against the inner surface of the brake drum 1'. This pressing process occurs radially along the brake drum 1', and the direction of the friction force extends circumferentially along the brake drum 1'. That is, the friction pads contact the inner surface of the brake drum 1' from the center outward and generate friction, thereby slowing down the wheel speed and achieving the braking effect. Therefore, to ensure the braking effect, the axial and radial dimensions of the brake drum 1' are relatively large.

[0034] Especially for vehicles in the 4.5-ton class, the inner diameter of the brake drum 1' of the standard central parking system is set at 200mm. When the vehicle is equipped with a reducer with a two-stage gear reduction design, the limited distance (usually less than 100mm) between the axis of the gear shaft 3' that is connected to the brake drum 1' and the reducer housing 2' becomes a major obstacle to the placement of the drum brake.

[0035] If the drum brake is forcibly placed between the gear shaft 3′ and the reducer housing 2′ to reduce the axial space occupied by the drum brake, the center distance of the secondary gears will inevitably need to be increased to at least 170mm to meet the space requirements for brake installation. This adjustment will cause the entire reducer to expand in size, thereby affecting the vehicle's lightweight design goals and potentially triggering a readjustment of the vehicle chassis layout, increasing design and manufacturing costs.

[0036] In addition, the weight of a drum brake can reach about 3.5 kg. Under high-speed operation conditions, this weight not only increases the rotational inertia of the transmission system, but also leads to a significant increase in energy consumption.

[0037] Another type of central parking system uses a ratchet and pawl mechanism to lock the vehicle. However, because the ratchet and pawl only have a single tooth engaging, this structure has relatively weak torque capacity when providing parking locking. In actual use, when the vehicle is parked on a slope or subjected to external impact, the single-tooth ratchet may not be able to withstand the resulting large torque, causing the parking mechanism to fail, the vehicle to slip unexpectedly, and seriously threatening driving safety.

[0038] In summary, if drum brakes are used for parking, the central parking system will be large and heavy, which is not conducive to vehicle weight reduction and will also increase vehicle energy consumption. When a ratchet and pawl type central parking system is used, since the ratchet and pawl only have a single tooth meshing, it cannot meet the braking torque requirements when the parking force demand is large.

[0039] Please see Figures 2-6 , Figure 2 This is a schematic diagram of the central parking system in an embodiment of the present invention; Figure 3 This is a schematic diagram of the second tooth structure 200; Figure 4 This is a projection of the cam along the transmission shaft axis in an embodiment of the present invention; Figure 5 yes Figure 4 Force analysis diagram; Figure 6 This is a schematic diagram of the cam after it has been unfolded.

[0040] like Figure 2 and Figure 3 The present invention provides a central parking system, including a drive assembly 300, a seat 3, a first gear structure 100, a second gear structure 200, and a drive shaft 15 that is tractively connected to the output end of a vehicle motor. The seat 3 supports the drive assembly 300, which drives the first gear structure 100 to move axially to engage with or move away from the second gear structure 200. The second gear structure 200 rotates with the drive shaft 15. The drive shaft 15 can be a drive shaft tractively connected to the output shaft of the vehicle motor or a gear shaft of a reducer. The second gear structure 200 is connected to the drive shaft 15 by a spline, and the second gear structure 200 does not move axially with the drive shaft 15. In the example shown in the figure, the drive shaft 15 is a gear shaft of a reducer.

[0041] The central parking system also includes a housing 18, which is, for example, the housing of a reducer. The reducer housing has an opening, and the second tooth structure 200 is located inside the reducer housing. The end of the drive shaft 15 extends axially beyond the surface of the second tooth structure 200 that faces the first tooth structure 100. A seat 3 is a fixed end, fixedly connected to the housing 18. In the example shown, the seat 3 is fixedly connected to the reducer housing. The first tooth structure 100 is slidably fitted onto the seat 3. Under the drive assembly 300, the first tooth structure 100 moves axially along the drive shaft 15 to engage with or move away from the second tooth structure 200. Figure 2 The state shown is that the two tooth structures are far apart. In the solution of this application, the traditional drum brake uses friction braking on the circumferential sidewall of the brake drum. Instead, it adopts a method of axial meshing of two tooth structures, which significantly reduces the turning radius of the first tooth structure 100, and thus correspondingly reduces the size of the seat 3, thereby realizing the miniaturization of the central parking system.

[0042] In the above embodiments, both the first tooth structure 100 and the second tooth structure 200 have a plurality of teeth 13; the tooth height H of each tooth 13 is parallel to the axis of the transmission shaft 15, the axis extends along the axial direction p, and each tooth 13 extends radially along the transmission shaft 15 and is arranged circumferentially along the transmission shaft 15, thereby increasing the number of teeth 13 and significantly increasing the transmitted torque. The second tooth structure 200 is annular, and a plurality of teeth 13 are provided on the axial surface of the second tooth structure 200 facing the first tooth structure 100. In the example shown, the second tooth structure 200 can be formed by welding a plurality of teeth 13 onto the flange 16 of the reducer gear shaft. Of course, other structures are also possible, as long as they can rotate with the transmission shaft 15. By adopting the method in this embodiment, the torque bearing capacity is significantly improved compared with the traditional ratchet and pawl brake. In addition, in the technical solution of this application, the transmission shaft 15 and the actuator motor 1 can be controlled by the control system. When the two tooth surfaces in the axial direction abut each other, the transmission shaft 15 can continue to rotate a certain angle so that the two tooth structures can mesh.

[0043] The first tooth structure 100 includes a brake ring, which is circular. The tooth body 13 is disposed on the surface of the brake face facing the second tooth structure 200. Since the tooth height H of each tooth body 13 is parallel to the axial direction of the transmission shaft 15, that is, the tooth body 13 belonging to the second tooth structure 200 and the tooth body 13 belonging to the first tooth structure 100 protrude towards each other along the axial direction. At the same time, in the radial direction of the transmission shaft 15, each tooth body 13 extends a certain distance.

[0044] The seat 3 covers the opening of the housing 18 and is connected to the housing 18 by bolts 2 before being sealed with adhesive. The seat 3 and the housing 18 form a braking space, and the first tooth structure 100 can move within the braking space. That is, when the first tooth structure 100 is engaged with the second tooth structure 200 (braking position), part of the first tooth structure 100 extends into the housing 18 through the opening. The seat 3 specifically includes an inner cylinder 11 and an outer cylinder 17. The outer cylinder 17 is a cylindrical structure with one end closed and the other end open. The closed end of the outer cylinder 17 is defined as the closed end, which is parallel to the plane containing the radial direction of the transmission 15. The inner cylinder 11 is located radially inside the outer cylinder 17 and is fixedly connected to the end face of the closed end of the outer cylinder 17, which can be riveted or integrally formed. The open end is opposite to the opening of the shell 18, so that the seat 3 is connected to the shell 18. An annular cavity is defined between the inner cylinder 11 and the outer cylinder 17. The annular cavity extends axially, and the end of the inner cylinder 11 away from the bottom of the outer cylinder 17 extends axially. The front end of the transmission shaft 15 extends into the inner cylinder 11, thereby further reducing the space occupied by the central parking system in the axial direction, and also reducing the length of the axial movement of the first tooth structure 100. The tooth body 13 is located radially on the side of the inner cylinder 11 away from the transmission shaft 15, and is opposite to the annular cavity in the axial direction. A first tooth structure 100 is provided within the annular cavity. The first tooth structure 100 includes a brake ring. The surface of the brake ring facing the second tooth structure 200 is provided with teeth 13. The brake ring is located within the annular cavity and slides against the cavity wall under the drive of the drive assembly 300. Specifically, the outer sidewall of the brake ring is provided with several raised arcs. The raised arcs interlock with the recesses of the annular cavity wall, thereby restricting the circumferential movement of the brake ring. However, the raised arcs can slide axially within the recesses.

[0045] The drive assembly 300 includes a pusher and a return member. The pusher has a push-out mode and a retraction mode. In the push-out mode, the pusher drives the first tooth structure 100 to move towards the second tooth structure 200 and causes the return member to deform to accumulate energy. In the retraction mode, the return member drives the first tooth structure 100 to move away from the second tooth structure 200. Through the coordinated action of the pusher and the return member, the first tooth structure 100 can quickly approach and accurately align with the second tooth structure 200. In the push-out mode, the pusher can quickly push the first tooth structure 100 towards the second tooth structure 200, ensuring that the two can quickly and accurately mesh, achieving effective braking or locking. In the retraction mode, the return member uses its accumulated energy to automatically drive the first tooth structure 100 away from the second tooth structure 200, achieving an automatic reset function. This also simplifies the mechanical structure and reduces the need for external control components. Of course, you can also omit the spring-back mechanism and only install the push-out mechanism. The push-out mechanism can be a linear electromagnet, an electric push rod, or a lead screw driven by a stepper motor or servo motor.

[0046] See also Figure 2 The push-out component specifically includes a drive shaft 10, a cam 19, and an actuator motor 1. The drive shaft 10 is provided with the cam 19 and is arranged radially along the transmission shaft 15. The cam 19 rotates around the drive shaft 10. In this embodiment, the arrangement of the drive shaft 10 radially along the transmission shaft 15 and the movement of the first tooth structure 100 by the cam 19 can further reduce the space occupied by the drive assembly 300 in the axial direction of the transmission shaft 15, thereby reducing the size of the central parking system.

[0047] Combination Figure 2 , Figures 4-6 The cam 19 rotates around the drive shaft 10. The cam 19 has a small-diameter side and a large-diameter side. When the cam 19 rotates from the small-diameter side to the large-diameter side, it is in the pushing-out condition; when it rotates back from the large-diameter side to the small-diameter side, it is in the retraction condition. Thus, when the cam 19 rotates from the small-diameter side to the large-diameter side, its shape change converts the rotational motion into the linear motion of the pushing component. When the cam 19 returns from the large-diameter side to the small-diameter side, the spring-loaded component uses its previously stored energy to automatically drive the first tooth structure 100 away from the second tooth structure 200, achieving the retraction condition. By using the rotation of the cam 19 to drive the first tooth structure 100 to move axially, the size of the central parking system is reduced, while also simplifying the structure.

[0048] In the example shown in the figure, the drive shaft 10 extends radially and passes through the annular cavity. The portion of the drive shaft 10 located within the annular cavity is provided with a cam 19, that is, the cam 19 is also located within the annular cavity. In the axial direction, the cam 19 is located on the side of the first tooth structure 100 away from the second tooth structure 200. The drive shaft 10 extends through the outer cylinder 17 to form a insertion hole. After entering the seat 3 through the insertion hole, the bottom end of the drive shaft 10 passes through the annular cavity and abuts against the inner wall of the outer cylinder 17. The part of the bottom end that abuts against the inner wall of the outer cylinder 17 is provided with a mounting groove. A needle roller bearing 5 is provided in the groove, and the bottom end rotates with the wall of the mounting groove through the needle roller bearing 5. At the same time, a needle roller bearing 5 is also provided in the insertion hole. The drive shaft 10 located in the insertion hole rotates with the wall of the insertion hole through the needle roller bearing 5. The needle roller bearing 5 has a stamped outer ring, and the inner hole is directly connected to the drive shaft 10. The stamped outer ring of the needle roller bearing 5 is interference-fitted with the corresponding mounting groove and insertion hole. Through these two needle roller bearings 5, the drive shaft 10 can rotate freely.

[0049] The top end of the drive shaft 10 is located outside the seat 3 to connect with the power output end of the actuator motor 1. To prevent external impurities and moisture from entering the brake chamber through the insertion hole, an oil seal 4 is provided in the insertion hole. Compared with the needle roller bearing 5, the oil seal 4 is located closer to the actuator motor 1. The oil seal 4 is used to seal the internal gear oil. In this embodiment, two cams 19 are provided on the drive shaft 10. The cams 19 are symmetrically arranged radially along the seat 3, and the rotation positions of the two cams 19 are consistent. This makes the thrust on the first tooth structure 100 in the axial direction balanced. In the axial direction, the cams 19 are located between the end of the drive shaft 15 and the end face of the closed end of the outer cylinder 17.

[0050] The spring-loaded component includes a spring 7, which is sleeved on the outside of the inner cylinder 11 and located radially between the top of the toothed body 13 and the drive shaft 15. One axial end of the spring 7 indirectly abuts against the inner cylinder 11, and the other end abuts against the brake ring. Specifically, the side wall of the inner cylinder 11 has a groove, and a retaining ring 14 is interference-fitted in the groove. The retaining ring 14 extends radially and protrudes from the outer wall of the inner cylinder 11 so that it can directly or indirectly abut against the end of the spring 7 in the axial direction. In order to accommodate the axial dimension of the spring 7, an annular baffle 8 can also be sleeved on the outer wall of the inner cylinder 11. One axial side of the annular baffle 8 presses against the retaining ring 14, and the other side abuts against the end of the spring 7. The number and axial dimension of the annular baffle 8 can be adjusted to match the axial length of the spring 7.

[0051] The brake ring specifically includes a ring body 6, which is provided with teeth 13; a stepped structure 12 is formed on the inner ring side of the ring body 6, the stepped structure 12 includes a first platform and a second platform, the first platform and the second platform are opposite each other along the axial direction; the first platform abuts against the cam 19; the second platform abuts against the other end of the spring 7; the outer wall of the inner cylinder 11, the second platform and the inner wall of the ring body form a guide cavity, the guide cavity extends along the axial direction, and the spring is disposed in the guide cavity; in this way, the arrangement space of the spring can be increased, and the axial movable range of the first tooth structure 100 can be increased.

[0052] The inner wall of the outer cylinder 17 is provided with a radially extending annular flange 171. The inner cylinder 11 is located inside the annular flange 171 and is radially spaced from the annular flange 171. The annular flange 171 extends radially to form a boss. The surface of the boss facing the sealing end of the outer shell partially forms the groove wall of the mounting groove and partially forms the hole wall of the insertion hole. The surface of the boss facing the second tooth structure 200 and the side edge wall extending axially form the cavity wall of the annular cavity.

[0053] In other words, in this embodiment, the annular cavity is not a cavity of equal diameter. The annular cavity has a large-diameter section and a constricted section. The radial dimension of the large-diameter section is larger than that of the constricted section. In the axial direction, the large-diameter section is located on the side closer to the second tooth structure 200, and the constricted section is located on the side closer to the sealing end of the outer cylinder 17. The stepped structure 12 is located between the annular flange 171 and the inner cylinder 11, that is, the stepped structure 12 is located inside the constricted section. The radial dimension of the first surface of the stepped structure 12 matches the radial dimension of the cam 19 to ensure the driving strength. The second surface extends inward from the inner wall of the ring body 6 and slides in cooperation with the outer wall of the inner cylinder 11. The radial extension dimension of the second surface of the stepped structure 12 is adapted to the spring 7. In the axial direction, the surface of the annular flange 171 facing the second tooth structure 200 can form a stop cooperation with the ring body 6. By setting the annular flange, the first tooth structure 100 can be limited, reducing the pressure of the spring on the cam 19.

[0054] In an optional embodiment, the end of the inner cylinder 11 extends beyond the opening of the outer cylinder 17. The ring body 6 is flush with the end face of the outer cylinder 17 with the opening. The outer wall of the outer cylinder 17 is provided with a flap, which is connected to the shell portion 18. The end of the outer cylinder 17 with the opening is provided inside the shell portion 18 through the opening. The outer wall of the portion of the outer cylinder 17 located inside the shell portion 18 radially abuts against the inner wall of the shell portion 18. Optionally, the annular flange 171 and the flap are located on the same plane. The portion of the ring body 6 located inside the shell portion 18 of the outer cylinder 17 has its surface away from the annular flange 171 aligned with the end face of the outer cylinder 17. The tooth 13 is provided on the ring body 6 and is projected axially. The projection range of the tooth 13 is within the projection range of the annular flange 171. In the above embodiment, the annular cavity, the brake ring, and the second tooth structure 200 are coaxially arranged. In this way, the annular cavity guides the brake ring, ensuring the precise alignment of the first tooth structure 100 and the second tooth structure 200.

[0055] The following is a detailed description of the cam 19 structure in this application, combined with... Figure 2 and Figures 4-6 To understand.

[0056] Cam 19 is formed by curling a wedge-shaped body around drive shaft 10. That is, when cam 19 is projected along the axial direction of drive shaft 10, it forms a curled, closed helical surface. Unfolding this helical surface results in a wedge-shaped surface. The wedge-shaped surface is a plane with an inclined angle. The wedge-shaped surface has a lower side 192 and an upper side 191. The lower side 192 connects to drive shaft 10, and the upper side 191 abuts against the brake ring. The lower side 192 extends in a straight line, and the upper side 191 is inclined at an angle to the lower side 192, with an included angle α. The wedge-shaped body has a large-diameter end 193 on the large-diameter side and a small-diameter end 194 on the small-diameter side. 94. The large-diameter end 193 and the small-diameter end 194 are the left side 193a and the right side 194a connecting the upper side 191 and the lower side 192. The left side 193a and the right side 194a are set perpendicular to the lower side 192 and are set opposite to each other in the extending direction of the lower side 192. After curling, the end face of the small-diameter end 194 directly or indirectly abuts against the end face of the large-diameter end 193, and the inner wall of the wedge is in contact with the outer wall of the drive shaft 10. In the radial direction, the outer wall of the large-diameter end 193 extends beyond the outer wall of the small-diameter end 194. This can significantly increase the axial thrust of the drive shaft 10, realize the conversion of small torque and large thrust, and thus reduce the output torque of the actuator motor 1.

[0057] The following is a specific example to illustrate this embodiment. During operation, the drive motor drives the cam 19 to rotate. At position A where the cam 19 abuts against the brake ring, a circumferential force Ft is generated. The extension direction of Ft is tangent to the circumference of the circle at position A. Assuming that pressure P generates friction to balance this circumferential force Ft, the balancing force of pressure P is the force F that pushes the first tooth structure 100 to the left. In this embodiment, on the one hand, during the ejection condition, the drive shaft 10 only needs to output a small torque to generate a large thrust, thus reducing the torque requirement of the drive shaft 10.

[0058] For example, if the torque of the actuator motor 1 is T=0.9Nm, the radius of the small diameter end 194 of the cam 19 is r1=0.006m, the radius of the large diameter end 193 is r2=0.009m, and the friction system is μ=0.1, according to the formula Ft=T / r, the circumferential force of the small diameter end 194 is calculated to be Ft1=150N, and the circumferential force of the large diameter end 193 is calculated to be Ft2=100N. According to the formula P=Ft / μ, the thrust on the small diameter end 194 is calculated to be P1=1500N, and the thrust on the large diameter end 193 is calculated to be P2=1000N. Then the thrust F that pushes the first tooth structure 100 is F1=-1500N for the small diameter end 194 and F2=1000N for the large diameter end 193. That is to say, when the torque of the motor is 0.9nm, it is sufficient to push the first tooth structure 100 to move.

[0059] Optionally, the rotation center of the cam 19 in this application is located on the central axis P of the drive shaft 10, and the center of the circle at any position on the side wall of the wedge-shaped segment of the cam 19 is located at the rotation center. Therefore, in the retraction condition, the actuator 1 does not need to apply a large force to the first tooth structure 100 to prevent the two tooth structures from separating, thus ensuring the meshing effect of the two tooth structures. In this embodiment, the distance between the point of contact between the first tooth structure 100 and the cam 19 and the rotation center is relatively short. The counter-thrust force of the first tooth structure 100 on the cam 19 roughly passes through the rotation center, meaning it passes through the rotation center or is at a certain distance from the rotation center, which also enables the self-locking of the cam 19.

[0060] In one alternative embodiment, the cam 19 has a wedge-shaped section 195 and a constant-diameter section 196. The wedge-shaped body serves as the wedge-shaped section 195. The outer wall of the constant-diameter section 196 is equidistant from the central axis P of the drive shaft 10. The constant-diameter section 196 is connected to the large-diameter end 193 of the wedge-shaped section 195. The small-diameter end 194 abuts against the side of the constant-diameter section 196 away from the large-diameter end 193 in the circumferential direction of the drive shaft 10. When the first tooth structure 100 and the second tooth structure 200 mesh, the first tooth structure 100 abuts against the constant-diameter section 196. In this way, when the second tooth structure 200 meshes with the first tooth structure 100, the two tooth structure components will generate a large axial thrust. This thrust is applied to the point of action (large-diameter end 193) of the cam 19 through its own center and the center of rotation, thereby achieving self-locking and ensuring the meshing effect.

[0061] In the above embodiments, a speed reduction structure can be provided between the actuator motor and the drive shaft, which can be selected by those skilled in the art; optionally, in the technical solution of this application, in order to ensure that the two tooth structures mesh, a position sensor 9 can be provided, and the position sensor 9 is connected to the actuator motor signal; or an angle encoder can be provided in the actuator motor to control the rotation angle of the actuator motor to ensure that the two tooth structures mesh or disconnect.

[0062] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A central parking system, characterized in that, It includes a first tooth structure (100), a second tooth structure (200), a drive assembly (300), a seat (3), and a drive shaft (15) that is connected to the output end of the vehicle motor. The second tooth structure (200) and the drive shaft (15) rotate together. The first tooth structure (100) is slidably fitted to the seat (3), the seat (3) being a fixed end and used to support the drive assembly (300). Under the drive of the drive assembly (300), the first tooth structure (100) moves along the axial direction (P) of the transmission shaft (15) to mesh with or move away from the second tooth structure (200); the first tooth structure (100) includes a brake ring. The drive assembly (300) includes a drive shaft (10), a cam (19) and an actuator motor (1), wherein the drive shaft (10) is provided with the cam (19). The drive shaft (10) is arranged radially along the transmission shaft (15), and the cam (19) has a small diameter side and a large diameter side; The cam (19) includes a lower side (192) and an upper side (191), the lower side (192) being used to connect with the drive shaft (10), and the upper side (191) being used to abut against the brake ring; The cam (19) also includes a large-diameter end (193) located on the large-diameter side and a small-diameter end (194) located on the small-diameter side. The large-diameter end (193) and the small-diameter end (194) are the left side (193a) and the right side (194a) connecting the upper side (191) and the lower side (192). The end face of the small-diameter end (194) directly or indirectly abuts against the end face of the large-diameter end (193). In the radial direction, the outer wall of the large-diameter end (193) extends beyond the outer wall of the small-diameter end (194). The drive assembly (300) also includes a spring-loaded member, one end of which abuts against the seat (3) and the other end of which abuts against the brake ring.

2. The central parking system according to claim 1, characterized in that, Both the first tooth structure (100) and the second tooth structure (200) have a plurality of teeth (13); The tooth height (H) of each of the tooth bodies (13) is parallel to the axis of the drive shaft (15), and each of the tooth bodies (13) extends radially along the drive shaft (15) and is arranged circumferentially along the drive shaft (15).

3. The central parking system according to claim 2 further includes a housing (18), wherein the housing (18) is provided with the drive shaft (15) and the second gear structure (200), and the seat (3) is fixedly connected to the housing (18); The end of the drive shaft (15) extends axially (P) beyond the second tooth structure (200) and into the seat (3).

4. The central parking system according to claim 3, characterized in that, The seat (3) includes a fixedly connected inner cylinder (11) and outer cylinder (17). The inner cylinder (11) is located inside the outer cylinder (17). An annular cavity is defined between the inner cylinder (11) and the outer cylinder (17). The first tooth structure (100) includes a brake ring. The brake ring is located in the annular cavity and slides with the wall of the annular cavity. The annular cavity, the brake ring and the second tooth structure (200) are coaxially arranged.

5. The central parking system according to claim 4, characterized in that, One end of the inner cylinder (11) is fixed to the outer cylinder (17) in the axial direction (P), and the other end extends into the shell (18) and is located radially outside the drive shaft (15); The tooth (13) located in the second tooth structure (200) is located radially on the side of the inner cylinder (11) away from the drive shaft (15) and is axially (P) opposite to the annular cavity.

6. The central parking system according to claim 5, characterized in that, The cam (19) has a constant diameter section (196) connected to the large diameter end (193). The small diameter end (194) is connected to the side of the constant diameter section (196) away from the large diameter end (193) along the circumferential direction of the drive shaft (10). The outer wall of the constant diameter section (196) is equidistant from the rotation center of the cam (19). When the first tooth structure (100) meshes with the second tooth structure (200), the first tooth structure (100) abuts against the equal diameter section (196).

7. The central parking system according to claim 5, characterized in that, The brake ring includes a ring body (6), and the ring body (6) is provided with the teeth (13). The inner ring of the ring body (6) has a stepped structure (12) formed thereon. The stepped structure (12) includes a first platform and a second platform. The first platform and the second platform are opposite each other along the axial direction (P). The first platform abuts against the cam (19) and the second platform abuts against the spring. The outer wall of the inner cylinder (11), the second platform and the inner wall of the ring body (6) form a guide cavity, and the spring-loaded component is disposed in the guide cavity.

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