Thrust conversion structure for brake-by-wire system
Through the design of the segmented propulsion structure and the force-amplifying bearing assembly, the problems of large space occupation and non-compact structure of the thrust conversion structure in the wire control brake system are solved, compact progressive axial propulsion is achieved, and the braking effect is improved.
Patent Information
- Application Number
- CN202520059261.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2035-01-10
AI Technical Summary
The thrust conversion structure of the existing wire-controlled brake system has an unreasonable assembly method, occupies a large space, has a non-compact structure, and cannot achieve a progressive axial propulsion method, resulting in the inability to form a post-stroke boost braking effect.
It adopts a segmented propulsion structure, converting rotary motion into linear motion through thread transmission and force-enhancing bearing components, including thrust bearing components, screws and pistons. It uses the depth-varying raceway and thread pair, combined with the design of needle roller bearings and wave springs to achieve progressive axial propulsion.
The structure is compact and the space occupied is small. The segmented propulsion braking can be realized, thereby improving the braking effect and reducing the product size.
Smart Images
Figure CN223459777U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to vehicle braking technology, concretely relates to a thrust conversion structure for brake-by-wire system. BACKGROUND
[0002] At present, disc brakes of vehicles on the market are mainly divided into two categories of air pressure and hydraulic pressure according to different power transmission media, but air and hydraulic brake systems generally have problems such as complex structure, environmental pollution, slow response, complex control and the like, and cannot adapt to the development trend of future vehicle intelligentization and brake-by-wire. Therefore, the existing technology has appeared electric brake, and the main principle is that the rotary power output by the motor is converted into axial thrust through a conversion mechanism, the axial thrust pushes the brake disc to generate a braking effect.
[0003] However, the existing thrust conversion structure usually has the following problems: on the one hand, the assembly mode is unreasonable, the space is long, and the structure is not compact; on the other hand, it does not form a progressive axial pushing mode, so that the effect of post-stage force braking cannot be formed. UTILITY MODEL CONTENTS
[0004] In order to solve the problems in the above-mentioned technology, the utility model provides a technology with small space occupation, compact structure and segmented pushing brake.
[0005] The utility model provides a thrust conversion structure for brake-by-wire system, which comprises a thrust bearing assembly, a screw rod and a piston:
[0006] The thrust bearing assembly is arranged in sequence from front to back with a support disc, a rolling body and a driving disc, the support disc and the driving disc have depth-varying rolling grooves matched with the rolling body; the driving disc is provided with internal threads;
[0007] The screw rod has an inner cavity and external threads, the inner cavity has a spline hole matched with a shaft with external splines, and the external threads of the screw rod are matched with the internal threads to form a threaded pair;
[0008] The piston can move axially, the front side of the piston is the rear end of the screw rod, and the rear end of the piston is used for abutting against a brake disc to brake.
[0009] Preferably, a retaining sleeve is further included, the retaining sleeve is fixed on the jaw body, the driving disc has a disc body part and a screw sleeve, the screw sleeve has a needle roller bearing II at a position close to the disc body part, the screw sleeve passes through the inner hole of the retaining sleeve, and the retaining sleeve and the needle roller bearing II have a wave spring II therebetween;
[0010] The end of the screw sleeve and the annular part of the screw rod have a needle roller bearing I therebetween;
[0011] The snap spring, the gasket and the wave spring I are sequentially arranged between the retaining sleeve and the needle bearing I.
[0012] Preferably, the rear end of the screw rod is provided with a protrusion which is matched with the piston through a bearing structure.
[0013] Preferably, the rear end of the screw rod is provided with a guide pin, the front end of the guide pin is fixed in the middle part of the rear end of the screw rod, and the rear end of the guide pin is rotatably matched with the mounting blind hole of the piston.
[0014] Preferably, the guide pin is provided with a bushing at the position where the guide pin is mounted in the mounting blind hole.
[0015] Preferably, the bearing structure is a cylindrical roller bearing.
[0016] Preferably, the wave spring I is a single-turn wave spring, and the wave spring II is a multi-turn wave spring.
[0017] Preferably, the piston is provided with hemispherical grooves on both sides, steel balls are arranged in the grooves, and the steel balls are slidably matched with the clamp body.
[0018] Preferably, the raceway is three evenly distributed raceways arranged based on a spiral line, and the raceway is matched with the rolling element to convert the torque input by the driving disc into an axial thrust.
[0019] Preferably, the rolling element is arranged on a retainer.
[0020] The beneficial effects of the utility model are as follows:
[0021] 1. The utility model adopts a sectional type pushing structure, in the first section, rotation is converted into linear motion by thread transmission when eliminating idle stroke, and in the second section, rotation is converted into linear motion by a force increasing bearing assembly when clamping;
[0022] 2. The utility model adopts the mode of force increasing bearing, screw rod and spline transmission, and greatly reduces the structure size of the product. DRAWINGS
[0023] Figure 1 is a structure schematic diagram of a whole of a pushing mechanism assembly of a pushing force conversion structure for a wire control braking system of the utility model;
[0024] Figure 2 is a structure schematic diagram of an exploded view of a pushing mechanism of a pushing force conversion structure for a wire control braking system of the utility model;
[0025] Figure 3 is a structure schematic diagram of a whole sectional view of a pushing force conversion structure for a wire control braking system of the utility model;
[0026] Figure 4 This is a structural schematic diagram of a cross-sectional view of a piston anti-rotation structure of a thrust conversion structure for a wire-controlled brake system of the present invention;
[0027] Figure 5 This is a schematic structural diagram of a screw structure of a thrust conversion structure for a wire-controlled brake system of the present invention;
[0028] Figure 6 This is a schematic structural diagram of a piston and steel ball structure of a thrust conversion structure for a wire-controlled brake system of the present invention;
[0029] Figure 7 This is a structural diagram of a force-boosting bearing support disc and an active disc structure of a thrust conversion structure for a wire-controlled brake system of the present invention;
[0030] Figure 8 This is a structural schematic diagram of a spline shaft structure of a thrust conversion structure for a wire-controlled brake system of the present invention;
[0031] Description of reference numerals:
[0032] 1-thrust bearing assembly; 11-support plate; 12-rolling element; 121-cage; 13-active plate; 131-raceway; 132-internal thread; 14-needle roller bearing II; 15-wave spring II; 16-retaining sleeve; 161-plate body; 162-threaded sleeve; 17-circlip; 18-shim; 19-wave spring I; 20-needle roller bearing I;
[0033] 2-screw; 21-inner cavity; 211-spline hole; 22-external thread; 23-protrusion; 24-bearing structure; 25-guide pin; 26-bushing; 27-circular ring;
[0034] 3-piston; 31-groove; 32-steel ball; 33-mounting blind hole; 4-spline shaft; 5-brake disc; 6-caliper body. DETAILED DESCRIPTION
[0035] Example 1:
[0036] like Figures 1 to 7 As shown, a thrust conversion structure for a wire-controlled brake system of this embodiment includes a thrust bearing assembly 1, a screw 2 and a piston 3;
[0037] The thrust bearing assembly 1 is sequentially arranged from front to back with a support plate 11, a rolling element 12, and a driving plate 13. The support plate 11 and the driving plate 13 have a raceway 131 with varying depths that cooperates with the rolling element 12. The driving plate 13 is provided with an internal thread 132.
[0038] The screw rod 2 has an inner cavity 21 with a spline hole matched with the spline shaft 4 with an outer spline, and an outer thread 22 matched with the inner thread 132 to form a threaded pair; specifically, the driving disc 13 is a hollow structure with a transmission inner thread 132 inside matched with the screw rod 2 with an outer thread 22 to convert the rotary motion into linear motion. After receiving the rotary power of the motor, the spline shaft 4 with an outer spline transmits the rotary power to the screw rod 2 to rotate, and the driving disc 13 remains stationary in the initial stage, so that the screw rod 2 moves axially through the threaded pair.
[0039] The piston 3 can move axially, and the front side of the piston 3 is the rear end of the screw rod 2, so that the piston 3 moves axially when the screw rod 2 moves axially. The rear end of the piston 3 is used to abut against the brake disc 5 to brake. In the initial stage, there is a gap between the piston 3 and the brake disc 5.
[0040] The utility model adopts segmented type propelling structure, the first section is to eliminate idle stroke, and rotary motion is converted into linear motion by threaded drive, the second section is to clamp, and rotary motion is converted into linear motion by force increasing bearing assembly;
[0041] Specifically, the working process of the scheme of the embodiment is as follows:
[0042] The first section is to eliminate idle stroke (eliminate gap), and in this process: the horizontal propelling resistance of the piston 3 is F1, the corresponding friction torque between the transmission threaded pair is M1 under the resistance, the internal friction torque of the force increasing bearing assembly 1 is M2, and the friction torque of the rotation of the driving disc 13 is M3. The spline shaft 4 starts to rotate under the input torque M4, the rotary motion is transmitted to the screw rod 2 through the spline pair, and the driving torque of the screw rod 2 to the driving disc 13 is equal to the friction torque M1 between the threaded pair; at the same time, the driving disc 13 is hindered by the friction torques M2 and M3, and M1 is less than the sum of M2 and M3, so that the driving disc 13 remains stationary, the screw rod 2 starts to move horizontally while rotating, pushes the piston 3 to advance, until the gap between the piston 3 and the brake disc 5 is completely eliminated, then the piston 3 continues to move, the clamping force F3 starts to increase from zero, the resistance of the piston 3 to advance is the sum of F1 and F3, the friction torque M1 between the threaded pair, and the friction torque M2 simultaneously increases (the growth rate is less than M1), until the size of M1 is equal to the sum of M2 and M3, which is the critical point of the end of the first section movement;
[0043] The second section is the clamping stage, in which the thrust bearing assembly 1 provides axial thrust, the clamping force F3 further increases, the friction torque M1 between the threaded pairs also increases, in this process M1 is greater than the sum of M2 and M3, the driving disc 13 rotates and advances horizontally with the screw rod 2 under the driving of the friction torque M1, and stops until the target clamping force F4 is reached.
[0044] The principle of the thrust bearing assembly 1 is that when the driving disc 13 rotates, the rolling body 12 is in contact with the rolling body 12 with varying depth, which forces the driving disc 13 to move in the axial direction, that is, the process of converting rotary torque into linear thrust force is realized by the cooperation of the driving disc 13 and the rolling body 12, which increases the axial thrust.
[0045] Embodiment 2:
[0046] Based on embodiment 1, the embodiment has the following structure:
[0047] The embodiment also includes a retaining sleeve 16 fixed on the jaw body 6; the driving disc 13 has a disc body portion 161 and a threaded sleeve 162, the threaded sleeve 162 has a needle bearing II 14 near the position of the disc body portion 161; the threaded sleeve 162 passes through the inner hole of the retaining sleeve 16, and the retaining sleeve 16 and the needle bearing II 14 have a wave spring II 15; the wave spring II 15 can strengthen the pressure on the needle bearing II 14, so that the maximum friction torque that the driving disc 13 rotates to overcome is adjusted. In the installed state, the retaining sleeve 16 is fixed in the jaw body 6 under the pressing action of the wave spring II 15.
[0048] The wave spring II 15 supports the needle bearing II 14, when the driving disc 13 moves axially towards the retaining sleeve 16, the wave spring II 15 is compressed, and the driving disc 13 rotates through the needle bearing II 14; when the brake is removed later, the wave spring II 15 is reset.
[0049] The threaded sleeve 162 and the annular portion 27 of the screw rod 2 have a needle bearing I20; the needle bearing I20 prevents the screw rod 2 from directly contacting and rubbing with the snap spring 17 in the piston 3 when the screw rod 2 rotates, and prevents the screw rod 2 from being stuck when it contacts the driving disc 13 under a large input torque when it retreats to the far right end.
[0050] The retaining sleeve 16 and the needle bearing I 20 have a snap spring 17, a gasket 18 and a wave spring I 19 in sequence. That is, the circular ring part 27 of the screw rod 2 contacts the needle bearing I 20 to complete rotation, and when the circular ring part 27 of the screw rod 2 moves axially, the wave spring I 19 stably supports the needle bearing I 20 through its characteristics.
[0051] The rear end of the screw rod 2 has a protruding part 23 which cooperates with the piston 3 through a bearing structure 24.
[0052] The rear end head of the screw rod 2 is provided with a guide pin 25, the front end of which is fixed in the middle part of the rear end of the screw rod 2, and the rear end of the guide pin 25 is rotatably matched with the mounting blind hole 33 of the piston 3.
[0053] The guide pin 25 has a bushing 26 at the position where it is installed in the mounting blind hole 33. The guide pin 25 is arranged at the head of the screw rod 2, so that the axis of the screw sleeve 162 can be prevented from tilting. That is, one end of the guide pin 25 is coaxially fixed with the screw rod 2, and the other end rotates in the bushing 26.
[0054] The bearing structure 24 is a cylindrical roller bearing.
[0055] The wave spring I 19 is a single-turn wave spring, and the wave spring II 115 is a multi-turn wave spring. The wave spring II 115 can apply a load to the driving disc 13 in the initial stage to increase the friction torque between the driving disc 13 and the supporting disc 11. In addition, the wave spring I 19 can prevent the first needle bearing 417 from moving axially and limit the position.
[0056] The piston 3 is provided with hemispherical recesses 31 on both sides, and steel balls 32 are arranged in the recesses 31. The steel balls 32 are in sliding cooperation with the plier body 6 to prevent the piston 3 from rotating.
[0057] The working process of the thrust conversion structure of the embodiment is as follows:
[0058] The first section is to eliminate the air gap, in which the horizontal pushing resistance of the piston 3 is F1, the corresponding friction torque between the transmission screw pairs is M1, the initial assembly state pressure of the wave spring II is F2, the internal friction torque of the force increasing bearing assembly 1 is M2, and the friction torque of the needle bearing II to the driving disc 13 is M3. The spline shaft 4 starts to rotate under the input torque M4, the rotary motion is transmitted to the screw rod 2 through the spline pair, and the driving torque of the screw rod 2 to the driving disc 13 is equal to the friction torque M1 between the screw pairs. At the same time, since the driving disc 13 is hindered by the friction torques M2 and M3, and M1 is less than the sum of M2 and M3, the driving disc 13 remains stationary, the screw rod 2 starts to move horizontally while rotating, pushes the piston 3 forward, and then the piston 3 continues to move, the clamping force F3 starts to increase from zero, the corresponding piston 3 advancing resistance is the sum of F1 and F3, the friction torque M1 between the screw pairs, and the friction torque M2, which increases at the same time (the growth rate is less than M1), until M1 is equal to the sum of M2 and M3, which is the critical point of the end of the first section;
[0059] The second section is the clamping stage, in which the clamping force F3 further increases, and the friction torque M1 between the screw pairs also increases at the same time. In this process, M1 is greater than the sum of M2 and M3, the driving disc 13 rotates and horizontally advances together with the screw rod 2 under the driving of the friction torque M1, and stops until the target clamping force F4 is reached.
[0060] In this scheme, the friction torques M1, M2 and M3 are determined by the friction characteristics of the parts themselves and the loads they bear. Therefore, in order to ensure the accuracy of the movement process, the friction coefficients of each component and the advancing resistance of the piston should be designed reasonably, the lead P1 of the transmission screw and the lead P2 of the force increasing bearing should be designed reasonably (which determines the slopes K1 and K2 of the growth of M1 and M2, and K1 should be greater than K2 during the growth process), and the force value F2 of the wave spring 2 should be fully calculated and verified when the wave spring 2 is designed.
[0061] By designing appropriate friction torques between the screw transmission pairs (constant during the air gap, and increasing with the increase of the piston thrust during the clamping) and the friction torques of the internal rolling bodies of the force increasing bearing (constant during the air gap, and the size can be adjusted by adjusting the force value of the wave spring 2, and increasing with the increase of the piston thrust during the clamping), the segmented pushing movement is realized.
[0062] The embodiment adopts the mode of force increasing bearing, screw rod and spline transmission, which greatly reduces the structure size of the product.
[0063] Embodiment 3:
[0064] The raceways 131 are three evenly distributed raceways 131 based on spiral line arrangement, which cooperate with the rolling bodies 12 to convert the torque input by the driving disc 13 into axial thrust; when the driving disc 13 rotates, the raceways 131 in the form of spiral line are arranged to be in contact with the rolling bodies 12, forming rotary force and axial thrust to improve the clamping force for braking.
[0065] The rolling bodies 12 are arranged on the retainer 121. The retainer 121 is used to make the rolling bodies 12 rotate more stably and avoid position disengagement.
[0066] Example 4:
[0067] The steel ball 32 is a standard steel ball; the bushing 26 is a standard bushing; the piston 3 is a conventional cylindrical structure; the needle bearing is a standard bearing; the gasket 18 is a circular flat gasket; and the retainer 121 is used to keep the relative positions of the rolling bodies 12.
Claims
1. A thrust conversion structure for a brake-by-wire system; characterized by, The utility model relates to a kind of screw rod and piston brake, including: Thrust bearing assembly (1), support disc (11) is arranged in order from front to back, rolling element (12) and driving disc (13), the support disc (11) and driving disc (13) have the raceway (131) of varying depth cooperation with rolling element (12);The driving disc (13) is equipped with internal thread (132); Screw rod (2) has inner cavity (21) and external thread (22), the inner cavity (21) has spline hole (211), spline hole (211) cooperates with spline shaft (4) with outer spline, the external thread (22) of screw rod (2) is formed with internal thread (132) and is matched with screw pair; Piston (3) can be axially moved, the front side of piston (3) is the rear end of screw rod (2), and the rear end of piston (3) is used to resist brake disc (5) and brake.
2. The thrust conversion structure for a brake-by-wire system according to claim 1, characterized by, It further includes retaining sleeve (16), the retaining sleeve (16) is fixed on jaw body (6);The driving disc (13) has disc body part (161) and screw sleeve (162), the screw sleeve (162) is close to the position of disc body part (161) and has needle roller bearing II (14);The screw sleeve (162) passes through the inner hole of retaining sleeve (16), and there is wave spring II (15) between retaining sleeve (16) and needle roller bearing II (14); The end of screw sleeve (162) and the circular ring part of screw rod (2) have needle roller bearing I (20); The retaining sleeve (16) and needle roller bearing I (20) have snap spring (17), gasket (18) and wave spring I (19) in order.
3. The thrust conversion structure for a brake-by-wire system according to claim 1, characterized by, The rear end of screw rod (2) has protruding part (23), and the protruding part (23) is matched with piston (3) by bearing structure (24).
4. The thrust conversion structure for a brake-by-wire system according to claim 3, characterized by, The rear end head of screw rod (2) is provided with guide pin (25), the front end of guide pin (25) is fixed in the middle part of the rear end of screw rod (2), and the rear end of guide pin (25) is rotatably matched with the mounting blind hole (33) of piston (3).
5. The thrust conversion structure for a brake-by-wire system according to claim 4, characterized by, The guide pin (25) is provided with bushing (26) at the position installed in the mounting blind hole (33).
6. The thrust conversion structure for a brake-by-wire system according to claim 4, characterized by, The bearing structure (24) is cylindrical roller bearing.
7. The thrust conversion structure for a brake-by-wire system according to claim 2, characterized by, Wave spring I (19) is single-turn wave spring, and wave spring II (15) is multi-turn wave spring.
8. The thrust conversion structure for a brake-by-wire system according to claim 1, characterized by, The piston (3) is provided with hemispherical recess (31) on both sides, and steel ball (32) is arranged in recess (31), and the piston (3) is slidably matched with jaw body (6) by steel ball (32).
9. The thrust conversion structure for a brake-by-wire system according to claim 1, characterized by, The raceway (131) is three evenly distributed raceways (131) based on spiral line arrangement, and the raceway (131) is matched with rolling element (12) to convert the torque input by driving disc (13) into axial thrust.
10. The thrust conversion structure for a brake-by-wire system according to claim 1, characterized by, Rolling element (12) is arranged on retainer (121).