Mechanical brake using self-circulation lead screw assembly

Abstract

The utility model discloses a mechanical brake using a self-circulation lead screw assembly, which belongs to the technical field of automotive electronic mechanical braking, and comprises an actuator, a caliper body, an output shaft, a circulation lead screw, an end cover, a brake pad assembly and a brake disc, the actuator is arranged at the top end of the caliper body, the output shaft is arranged at the top end of the caliper body and penetrates through the caliper body, and the circulation lead screw is arranged on the end cover. The part, penetrating through the caliper body, of the output shaft is connected with a circulating lead screw, the circulating lead screw is located in the caliper body and provided with a needle bearing, a force sensor is arranged above the needle bearing, the end, away from the output shaft, of the circulating lead screw is connected with an end cover, and the end, away from the circulating lead screw, of the end cover is connected with a brake pad assembly. According to the mechanical brake using the self-circulation lead screw assembly, the waterproof grade of a circulation lead screw reaches the IP69 grade by using a circulation lead screw structure with the surface not punched, the service life of a whole caliper is longer, and the mechanical brake is safer.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive electro-mechanical braking, in particular to a mechanical brake using a self-circulating lead screw assembly. Background Art

[0002] The electro-mechanical braking device (EMB) uses a motor and a mechanical transmission mechanism to cooperate to drive the brake to brake. The electro-mechanical braking device has the characteristics of simple structure, sensitive response, stable transmission of load and no need to set up hydraulic pipelines, etc., and has a high braking efficiency. The electro-mechanical braking device can improve the safety, controllability and comfort of the vehicle.

[0003] At present, the ball screw nut pair used in electro-mechanical braking has a circulator structure, that is, structures such as circulators are installed on the ball nut. The raceway on the ball nut is long, while the raceway on the lead screw is short. This requires drilling holes in the screw nut, which results in the screw nut not being a complete surface. When the nut extends outside the piston hole, there will be a situation where it cannot be sealed, and ultimately it will lead to water seepage in the brake caliper and damage to the entire mechanical brake caliper. Therefore, there is an urgent need for a mechanical brake using a self-circulating lead screw assembly to overcome the problems existing in the above technology. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a mechanical brake using a self-circulating lead screw assembly. By setting the reverser on the lead screw and not drilling holes on the outer surface of the nut, the use of this structure of the circulating lead screw makes the operation of the lead screw and the nut smoother, with higher transmission efficiency, and enables the waterproof level of the circulating lead screw to reach IP69 level, making the life of the entire caliper higher and more safe and reliable.

[0005] To achieve the above purpose, the utility model provides a mechanical brake using a self-circulating lead screw assembly, including an actuator, a caliper body, an output shaft, a circulating lead screw, an end cover, a brake pad assembly and a brake disc. The actuator is arranged at the top of the caliper body. The output shaft is arranged at the top of the caliper body and passes through the caliper body. The part of the output shaft passing through the caliper body is connected to the circulating lead screw. The circulating lead screw is located inside the caliper body. A needle roller bearing is arranged on the circulating lead screw. A force sensor is arranged above the needle roller bearing. One end of the circulating lead screw away from the output shaft is connected to the end cover. One end of the end cover away from the circulating lead screw is connected to the brake pad assembly. The brake disc is located inside the brake pad assembly.

[0006] Preferably, a gasket for protecting the force sensor and the needle roller bearing is arranged between the force sensor and the needle roller bearing.

[0007] Preferably, the circulating lead screw includes a lead screw, a nut and a reverser. One end of the lead screw is connected to the output shaft. The nut is sleeved on the end of the lead screw away from the output shaft, and the length of the nut is less than that of the lead screw. The reverser is located between the nut and the lead screw, and a plurality of continuous balls are arranged between the nut and the lead screw.

[0008] Preferably, the lead screw includes a spline hole, a groove and a lead screw groove. The output shaft is inserted into the spline hole to be connected with the lead screw, and a snap ring is clamped in the groove to fix the connection between the output shaft and the lead screw. The lead screw groove is arranged at the end of the lead screw away from the output shaft. One end of the lead screw groove is connected to the needle roller bearing, and the other end is provided with a first anti-rotation boss.

[0009] Preferably, the length of the nut is greater than that of the lead screw groove, and the nut is sleeved on the outside of the lead screw groove. A reverse channel for the reverse of the balls is arranged inside the nut. A guide groove is arranged at one end of the nut close to the output shaft. A stop screw is arranged on the clamp body. One side of the stop screw is fixed on the outside of the clamp body, and the other side passes through the clamp body and is placed in the guide groove.

[0010] Preferably, the end cover is press-fitted with the nut with interference, and sealant is used for sealing at the connection. The end cover is a three-layer stepped hollow cylindrical structure. The nut is connected to the layer with the smallest radius. A dust cover is arranged on the outside of the second layer of the end cover. An O-ring for sealing is arranged on the outside of the dust cover. A second anti-rotation boss is arranged on the inner side of the bottom of the end cover, and the outside is connected to the brake pad assembly.

[0011] Preferably, the brake pad assembly includes a bracket, an inner friction plate and an outer friction plate. The inner friction plate is connected to the end cover and is slidably connected to the inside of the upper side of the bracket. The outer friction plate is fixedly connected to the inside of the lower side of the bracket. A brake disc is arranged between the inner friction plate and the outer friction plate.

[0012] Therefore, the mechanical brake using the self-circulating lead screw assembly with the above structure of the present invention has the following advantages:

[0013] 1. The reverser is arranged on the lead screw, making the operation of the lead screw and the nut smoother and the transmission efficiency higher;

[0014] 2. Anti-rotation bosses are arranged at both ends of the lead screw and the end cover, so that the lead screw will not be stuck when it rotates to the bottom of the piston;

[0015] 3. The end cover and the nut adopt a split design and are combined by interference. At the same time, sealant is applied at the connection between the end cover and the nut to prevent leakage;

[0016] 4. A spacer is used to weaken the influence on the force sensor when the friction of the screw rotation is transmitted to it. At the same time, the plain bearing can be used as a rolling element to eliminate the frictional force of the ball screw.

[0017] 5. An O-ring is used for sealing to ensure that when the dust cover is broken or disengaged, the circulating screw of the brake will not leak.

[0018] 6. There are no holes on the outer surface of the nut, and the waterproof level of the circulating screw reaches IP69, making the life of the entire caliper better and safer.

[0019] The technical solution of the present utility model will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0020] Figure 1 It is an overall structure diagram of a mechanical brake using a self-circulating screw assembly of the present utility model;

[0021] Figure 2 It is a sectional structure diagram of a mechanical brake using a self-circulating screw assembly of the present utility model;

[0022] Figure 3 For Figure 2 an enlarged view of the structure at I;

[0023] Figure 4 It is an exploded view of the circulating screw of a mechanical brake using a self-circulating screw assembly of the present utility model;

[0024] Figure 5 It is an assembly drawing of the circulating screw of a mechanical brake using a self-circulating screw assembly of the present utility model;

[0025] Reference Signs:

[0026] 1. Actuator; 2. Output shaft; 3. Caliper body; 4. Anti-rotation screw; 5. Circulating screw; 51. Screw; 511. Spline hole; 512. Groove; 513. Screw groove; 52. Ball; 53. Reverser; 54. Nut; 541. Guide groove; 55. First anti-rotation boss; 6. End cover; 61. Second anti-rotation boss; 7. Brake pad assembly; 71. Inner friction plate; 72. Outer friction plate; 73. Bracket; 8. Brake disc; 9. Dust cover; 10. O-ring; 11. Needle roller bearing; 12. Spacer; 13. Force sensor; 14. Snap ring; 15. Connecting screw; 16. Guide pin. Detailed Embodiment

[0027] Embodiment

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. The components of the embodiments of the present utility model usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0030] As Figures 1 - 5 shown, a mechanical brake using a self-circulating lead screw assembly of the present utility model includes an actuator 1, a caliper body 3, an output shaft 2, a circulating lead screw 5, an end cover 6, a brake pad assembly 7 and a brake disc 8. The actuator 1 is arranged at the top of the caliper body 3, and the output shaft 2 is arranged at the top of the caliper body 3 and passes through the caliper body 3. The part of the output shaft 2 passing through the caliper body 3 is connected to the circulating lead screw 5. The circulating lead screw 5 is located inside the caliper body 3. A needle roller bearing 11 is arranged on the circulating lead screw 5, and a force sensor 13 is arranged above the roller bearing. One end of the circulating lead screw 5 away from the output shaft 2 is connected to the end cover 6, and one end of the end cover 6 away from the circulating lead screw 5 is connected to the brake pad assembly 7. The brake disc 8 is located inside the brake pad assembly 7.

[0031] A gasket 12 for protecting the force sensor 13 and the needle roller bearing 11 is arranged between the force sensor 13 and the needle roller bearing 11.

[0032] The circulating lead screw 5 includes a lead screw 51, a nut 54 and a reverser 53. One end of the lead screw 51 is connected to the output shaft 2. The nut 54 is sleeved on the end of the lead screw 51 away from the output shaft 2, and the length of the nut 54 is less than that of the lead screw 51. The reverser 53 is located between the nut 54 and the lead screw 51, and a plurality of continuous balls 52 are also arranged between the nut 54 and the lead screw 51.

[0033] The lead screw 51 includes a spline hole 511, a groove 512 and a lead screw groove 513. The output shaft 2 is inserted into the spline hole 511 to be connected to the lead screw 51, and a circlip 14 is clamped in the groove 512 to fix the connection between the output shaft 2 and the lead screw 51. The lead screw groove 513 is arranged at the end of the lead screw 51 away from the output shaft 2. One end of the lead screw groove 513 is connected to the needle roller bearing 11, and the other end is provided with a first anti-rotation boss 55.

[0034] The length of the nut 54 is greater than that of the lead screw groove 513, and the nut 54 is sleeved outside the lead screw groove 513. A reverse channel for reversing the ball 52 is provided inside the nut 54. A guide groove 541 is provided at one end of the inner side of the nut 54 close to the output shaft 2. A stop screw 4 is provided on the clamp body 3. One side of the stop screw 4 is fixed to the outside of the clamp body 3, and the other side passes through the clamp body 3 and is placed in the guide groove 541.

[0035] The end cover 6 is press-fitted with the nut 54 with an interference fit, and a sealant is used for sealing at the connection. The end cover 6 is a three-layer stepped hollow cylindrical structure. The nut 54 is connected to the layer with the smallest radius. A dust cover 9 is provided on the outside of the second layer of the end cover 6. An O-ring 10 for sealing is provided on the outside of the dust cover 9. A second anti-rotation boss 61 is provided on the inner side of the bottom of the end cover 6, and the outside is connected to the brake pad assembly 7.

[0036] The brake pad assembly 7 includes a bracket 73, an inner friction plate 71 and an outer friction plate 72. The inner friction plate 71 is connected to the end cover 6 and is slidably connected to the inside of the upper side of the bracket 73. The outer friction plate 72 is fixedly connected to the inside of the lower side of the bracket 73. A brake disc 8 is provided between the inner friction plate 71 and the outer friction plate 72.

[0037] When installing the brake, the circulating lead screw 5 is inserted into the clamp body 3, and then the output shaft 2 is inserted into the spline hole 511, and a circlip 14 is used to lock and fix the device in the groove 512. The stop screw 4 is screwed into the clamp body 3 through the threaded hole on the clamp body 3. At this time, the top of the stop screw 4 is located in the guide groove 541 of the nut 54 in the circulating lead screw 5 device; then the needle roller bearing 11, the gasket 12 and the force sensor 13 are sleeved on the lead screw 51 in sequence, and the needle roller bearing 11 is close to the lead screw groove 513. The force sensor 13 is used to monitor the change of the force when the inner friction plate 71 and the outer friction plate 72 clamp the brake disc 8 during braking. The gasket 12 between the needle roller bearing 11 and the force sensor 13 can weaken the influence of the friction force generated when the lead screw 51 rotates on the force sensor 13. The circulating lead screw 5 and the end cover 6 are assembled by interference fit and sealant is applied at the connection to prevent leakage. At the same time, a dust cover 9 is provided on the outside of the connection, and an O-ring 10 is also provided on the outside of the dust cover 9 to ensure that when the dust cover 9 is broken or disengaged, the circulating lead screw 5 of the brake will not leak; finally, the brake pad assembly 7 is fixed to the clamp body 3 through the guide pin 16 and the connecting screw 15.

[0038] During operation, the actuator 1 issues an instruction, and the output shaft 2 drives the rotation of the lead screw 51 in the circulating lead screw 5. The lead screw 51 drives the ball 52 to rotate along the lead screw groove 513, so that the nut 54 moves forward within the range allowed by the guide groove 541. At the same time, when the ball 52 reaches the reverser 53, it enters the reverse channel in the nut 54 through the reverser 53 and reaches the rear of the last ball 52 for the next cycle. Such a structure no longer requires the traditional method of drilling holes in the nut 54 to install the reverser 53 for ball reversal. The entire surface of the lead screw 51 assembly has no openings, ensuring the integrity of the surface of the lead screw 51 assembly. The nut 54 pushes the inner friction plate 71 connected to the end cover 6 to move, causing the inner friction plate 71 to clamp the brake disc 8. At this time, the bracket 73 will pull backward through the guide pin 16, driving the outer friction plate 72 close to the brake disc 8. At this time, the inner friction plate and the outer friction plate simultaneously hold the brake disc 8 tightly for deceleration braking. After the deceleration braking is completed, the nut 54 and the end cover 6 move backward driven by the ball 52. When the first anti-rotation boss 55 and the second anti-rotation boss 61 come into contact, the movement stops, and the braking process is completed.

[0039] Therefore, the mechanical brake using a self-circulating lead screw assembly of the present utility model adopts the above structure. By using a circulating lead screw structure with an undrilled surface, the waterproof level of the circulating lead screw reaches IP69, making the life of the entire brake higher and safer. And the reverser is arranged on the lead screw, making the operation of the lead screw and the nut smoother and the transmission efficiency higher. At the same time, anti-rotation bosses are provided at both ends of the lead screw and the end cover, so that the lead screw will not get stuck when rotating to the bottom of the piston. Moreover, an O-ring is used for sealing on the outside of the dust cover to ensure that when the dust cover is cracked or disengaged, the circulating lead screw of the brake will not leak. Finally, gaskets are used to weaken the influence of the friction of the lead screw rotation on the force sensor when transmitted, and at the same time, the plain bearing can act as a rolling element to eliminate the friction of the ball screw.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present utility model, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present utility model.

Claims

1. A mechanical brake using a self-circulating lead screw assembly, characterized in that: It includes an actuator, a caliper body, an output shaft, a circulating lead screw, an end cover, a brake pad assembly and a brake disc. The actuator is arranged at the top of the caliper body. The output shaft is arranged at the top of the caliper body and passes through the caliper body. The part of the output shaft passing through the caliper body is connected to the circulating lead screw. The circulating lead screw is located inside the caliper body. A needle roller bearing is arranged on the circulating lead screw. A force sensor is arranged above the needle roller bearing. One end of the circulating lead screw away from the output shaft is connected to the end cover. One end of the end cover away from the circulating lead screw is connected to the brake pad assembly. The brake disc is located inside the brake pad assembly.

2. The mechanical brake using a self-circulating lead screw assembly according to claim 1, wherein: A gasket for protecting the force sensor and the needle roller bearing is arranged between the force sensor and the needle roller bearing.

3. The mechanical brake using a self-circulating lead screw assembly according to claim 2, wherein: The circulating lead screw includes a lead screw, a nut and a reverser. One end of the lead screw is connected to the output shaft. The nut is sleeved on the end of the lead screw away from the output shaft, and the length of the nut is less than the length of the lead screw. The reverser is located between the nut and the lead screw, and a plurality of continuous balls are also arranged between the nut and the lead screw.

4. The mechanical brake using a self-circulating lead screw assembly according to claim 3, characterized in that: The lead screw includes a spline hole, a groove and a lead screw groove. The output shaft is inserted into the spline hole to be connected to the lead screw, and a snap ring is clamped in the groove to fix the connection between the output shaft and the lead screw. The lead screw groove is arranged at the end of the lead screw away from the output shaft. One end of the lead screw groove is connected to the needle roller bearing, and the other end is provided with a first anti-rotation boss.

5. A mechanical brake using a self-circulating lead screw assembly according to claim 4, characterized in that: The length of the nut is greater than the length of the lead screw groove, and the nut is sleeved on the outside of the lead screw groove. A reverse channel for the reverse of the balls is arranged inside the nut. A guide groove is arranged at one end of the nut close to the output shaft inside. A stop screw is arranged on the caliper body. One side of the stop screw is fixed on the outside of the caliper body, and the other side passes through the caliper body and is placed in the guide groove.

6. The mechanical brake using a self-circulating lead screw assembly according to claim 5, characterized in that: The end cover is press-fitted with the nut with interference, and sealant is used for sealing at the connection. The end cover is a three-layer stepped hollow cylindrical structure. The nut is connected to the layer with the smallest radius. A dust cover is arranged on the outside of the second layer of the end cover. An O-ring for sealing is arranged on the outside of the dust cover. A second anti-rotation boss is arranged on the inner side of the bottom of the end cover, and the outside is connected to the brake pad assembly.

7. A mechanical brake using a self-circulating lead screw assembly according to claim 6, characterized in that: The brake pad assembly is connected to the caliper body through connection screws and guide pins. The brake pad assembly includes a bracket, an inner friction pad and an outer friction pad. The inner friction pad is connected to the end cover and is slidably connected to the inside of the upper side of the bracket. The outer friction pad is fixedly connected to the inside of the lower side of the bracket. A brake disc is arranged between the inner friction pad and the outer friction pad.

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