An electronically controlled parking brake caliper

Abstract

The application relates to the technical field of brake calipers, in particular to an electronic control type parking brake caliper, which comprises a brake caliper body, a lead screw, a nut sleeve and a piston sleeve. A cavity is formed in the lead screw along the axis of the lead screw, an electric push rod is arranged in the cavity, an expansion hole is formed in the right end of the lead screw, the expansion hole is used for the expansion end of the electric push rod to expand and push the piston sleeve, an installation groove is formed in the outer surface of the nut sleeve, an electromagnetic lock is arranged in the installation groove, a locking pin matched with the electromagnetic lock is arranged on the surface of the nut sleeve, and an embedding groove for embedding the locking pin is formed in the inner wall of the piston sleeve. The application aims to solve the problem that the existing electronic parking brake system is usually driven by a motor to realize the parking locking function after the vehicle is parked and the parking releasing function before the vehicle starts, and if the motor suddenly fails, the caliper cannot be driven to complete the clamping action, so that the vehicle cannot be stably parked.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake calipers, in particular to an electronic control type parking brake caliper. BACKGROUND

[0002] At present, in the field of motor vehicle brake system manufacturing technology, especially in the actuator of vehicle electronic parking brake system, the structure of an actuator with electronic parking brake system is a rear caliper integrated brake caliper actuator, which is composed of a motor, a speed reduction mechanism and a brake caliper. For the rear caliper integrated brake caliper actuator, the existing vehicle electronic parking brake system actuator includes a transmission device and a brake caliper assembly. The output of the direct current motor in the transmission device is transmitted through a synchronous belt transmission mechanism and a involute few-tooth difference planetary gear transmission mechanism to reduce the speed and increase the torque, and then the rotary motion is converted into linear motion by a sliding screw transmission mechanism. The brake disc is braked in the form of a threaded sleeve pushing a piston and a brake block assembly.

[0003] The existing publication No. CN120207295B discloses an electronic mechanical brake parking mechanism and control method, belonging to the field of vehicle braking, including a speed reduction motor and a brake caliper. The motor shaft of the speed reduction motor is fixed with a locking disc. The inside of the motor shell of the speed reduction motor is provided with an electromagnetic locking assembly corresponding to the position of the locking disc. The locking head of the electromagnetic locking assembly corresponds to the locking hole opened on the locking disc. The inside of the motor shell is provided with a parking position sensor, and the end face side of the locking disc is fixed with a magnet cooperating with the parking position sensor. The inside of the motor shell is also provided with a locking position sensor for detecting the forward and backward movement of the locking head. The locking position sensor and the parking position sensor are electrically connected with the controller, and the controller is electrically connected with the speed reduction motor.

[0004] The publication No. CN101722945B discloses a brake caliper assembly of a vehicle electronic parking brake system, including a transmission mechanism assembly and a brake caliper assembly. The transmission mechanism assembly is arranged in the semi-closed area formed by the upper cover and the shell. The transmission mechanism assembly is connected with the brake caliper assembly. The transmission mechanism assembly is provided with an emergency release mechanism, the end of which extends to the outside of the shell. The extended end of the emergency release mechanism can be connected to the power source to drive the transmission mechanism assembly.

[0005] The existing electronic parking brake system is usually driven by a motor to realize the parking locking function after the vehicle is stopped and the parking release function before the vehicle starts. When the controller receives the vehicle parking brake instruction from the vehicle controller, the motor is controlled to rotate forward to drive the brake caliper to clamp until the set clamping force is generated. However, if the motor suddenly fails, the caliper cannot be driven to complete the clamping action, resulting in difficulty in stable parking of the vehicle. SUMMARY

[0006] The electronic control type parking brake caliper is provided to solve the problem that the existing electronic parking brake system is generally driven by a motor to realize parking locking after the vehicle is parked and parking release before the vehicle starts, and the caliper cannot be driven to complete clamping action if the motor suddenly fails, so that the vehicle cannot be parked stably.

[0007] To achieve the above object, the present application provides the following technical scheme:

[0008] An electronic control type parking brake caliper comprises a brake caliper body, a lead screw, a nut sleeve and a piston sleeve, the lead screw is provided with a cavity along its own axis, an electric push rod is installed in the cavity, the right end of the lead screw is provided with an expansion hole, the expansion hole is used for the expansion end of the electric push rod to expand and push the piston sleeve, the outer surface of the nut sleeve is provided with a mounting groove, an electromagnetic lock is installed in the mounting groove, the surface of the nut sleeve is provided with a locking pin matched with the electromagnetic lock, and the inner wall of the piston sleeve is provided with an embedding groove for the locking pin to be embedded.

[0009] In the normal state, the locking pin is retracted in the guide sleeve; in the trigger state, the locking pin is driven by the electromagnetic lock to pop out radially and embed in the embedding groove, so as to realize the mechanical locking of the nut sleeve and the piston sleeve.

[0010] Preferably, the lead screw is rotatably connected with the brake caliper body, the nut sleeve is sleeved on the outer periphery of the lead screw and is engaged with the lead screw through threads, the piston sleeve is sleeved on the outer periphery of the nut sleeve and is connected with the nut sleeve through splines and realizes axial sliding, and the right end of the nut sleeve abuts against the inner wall of the piston sleeve.

[0011] Preferably, the surface of the electromagnetic lock is fixedly connected with a guide sleeve arranged radially along the nut sleeve, the guide sleeve is a hollow structure with openings at both ends, and the locking pin is slidably connected in the guide sleeve.

[0012] Preferably, the hollow structure of the guide sleeve is composed of a spring cavity and a guide cavity which are connected in communication, and the top block at the end of the moving iron core of the electromagnetic lock is located in the spring cavity.

[0013] Preferably, a pre-tightening spring is further arranged in the spring cavity, the pre-tightening spring is sleeved on the outside of the locking pin, and the two ends of the pre-tightening spring are fixedly connected with the wall surface of the spring cavity and the surface of the locking pin respectively.

[0014] The pre-tightening force of the pre-tightening spring keeps the locking pin in the guide cavity; when the electromagnetic lock is powered on, the moving iron core pushes the top block to compress the pre-tightening spring and drives the locking pin to move outward along the guide cavity.

[0015] Preferably, a first wireless module is integrated in the space between the nut sleeve and the piston sleeve, the first wireless module is electrically connected with the electromagnetic lock, and the electric push rod has a second wireless module, and the second wireless module and the electric push rod are matched to realize wireless control and signal transmission.

[0016] Preferably, the locking pin is provided with a hemispherical head near the outer end of the piston sleeve, and the bottom of the embedding groove is provided with a circular arc transition bottom surface matched with the hemispherical head of the locking pin.

[0017] Preferably, the top block at the end of the moving iron core of the electromagnetic lock is matched with the end surface of the inner end of the locking pin.

[0018] Preferably, when the motor fails, the embedding groove on the inner wall of the piston sleeve is radially aligned with the locking pin when the electric push rod pushes the piston sleeve to the position where the brake pad is pressed against the brake disc.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. When the motor fails, the electric push rod in the screw shaft cavity can directly push the piston sleeve, quickly complete the adhesion of the brake pad and the brake disc to realize emergency braking, and when the piston sleeve moves to the braking position, the electromagnetic lock on the nut sleeve drives the locking pin to accurately embed into the embedding groove of the piston sleeve, forming a mechanical locking structure, effectively avoiding the piston sleeve from retreating due to the braking reaction force, ensuring the continuous and stable emergency braking force, and completely solving the core problems of being unable to park and the emergency braking force being easy to fail after the motor fails.

[0021] 2. In terms of structural simplicity, the design does not additionally add independent cavities, but fully utilizes the structural space of the existing components of the brake caliper, embeds the electric push rod in the screw shaft cavity, and opens an installation groove on the outer surface of the nut sleeve to assemble the electromagnetic lock, thereby simplifying the overall structural layout through high integration design, and avoiding the problem of structural obesity caused by the addition of emergency mechanisms.

[0022] 3. In terms of control convenience, the built-in wireless module realizes intelligent control, the wireless modules integrated in the gap between the nut sleeve and the piston sleeve and in the screw rod can respectively control the electromagnetic lock and the electric push rod wirelessly, without complex wired wiring, and the signal transmission is stable, which not only makes the triggering of emergency braking and locking more convenient, but also adapts to the intelligent control demand of vehicles, and improves the use flexibility. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structure schematic diagram of the whole cutting of the present application;

[0024] Figure 2 It is a structure schematic diagram of the cutting of the screw rod, the nut sleeve and the piston sleeve of the present application;

[0025] Figure 3 It is a structure schematic diagram of the cutting of the present applicationFigure 2 Enlarged view at A in the middle;

[0026] Figure 4 Structure diagram of the guide sleeve of the application.

[0027] In the figure: 1, brake caliper body; 2, screw rod; 3, nut sleeve; 4, piston sleeve; 5, electric push rod; 6, telescopic hole; 7, electromagnetic lock; 8, guide sleeve; 9, spring cavity; 10, guide cavity; 11, pre-tightening spring; 12, locking pin; 13, mounting groove; 14, embedded groove. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0029] Please refer to Figures 1 to 4 , the application provides a technical solution.

[0030] An electronic control type parking brake caliper, comprising a brake caliper body 1, a screw rod 2, a nut sleeve 3 and a piston sleeve 4, the screw rod 2, the nut sleeve 3 and the piston sleeve 4 are all built-in in the brake caliper body 1, the screw rod 2 is rotatably connected with the brake caliper body 1, the nut sleeve 3 is sleeved on the outer periphery of the screw rod 2 and is in threaded engagement with the screw rod 2, the piston sleeve 4 is sleeved on the outer periphery of the nut sleeve 3, is connected with the nut sleeve 3 through a spline and realizes axial sliding, and the end of the piston sleeve 4 away from the nut sleeve 3 abuts against a brake pad of the brake caliper.

[0031] In the initial state, the right end of the nut sleeve 3 abuts against the inner wall of the piston sleeve 4, in parking, the screw rod 2 is driven to rotate by a motor cooperating with a planetary gear mechanism, the screw rod 2 drives the nut sleeve 3 to move along the axial direction of the nut sleeve 3, the nut sleeve 3 further drives the piston sleeve 4, the piston sleeve 4 further drives the brake pad, the brake pad is pressed against a brake disc, and finally parking brake is completed.

[0032] The screw rod 2 is provided with a cavity along the axis, an electric push rod 5 is installed in the cavity, the screw rod 2 is provided with a telescopic hole 6 at the right end, the telescopic hole 6 is used for the telescopic end of the electric push rod 5 to extend out, and after the telescopic end extends out, the telescopic end can push the piston sleeve 4 to move axially, the above structure is used for coping with the emergency scene of automobile motor failure, when the motor of the electronic parking brake caliper fails, the electric push rod 5 can be started to make the telescopic end of the electric push rod 5 extend, the telescopic end pushes the piston sleeve 4, the brake pad and the brake disc are further pressed, emergency brake is realized, and the vehicle can be parked.

[0033] The outer surface of the nut sleeve 3 is provided with a mounting groove 13, and the electromagnetic lock 7 is mounted in the mounting groove 13. The surface of the nut sleeve 3 is provided with a locking pin 12 matched with the electromagnetic lock 7. The surface of the electromagnetic lock 7 is fixedly connected with a guide sleeve 8 arranged in the radial direction of the nut sleeve 3. The guide sleeve 8 has a hollow structure with openings at both ends. The locking pin 12 is slidingly connected in the guide sleeve 8. The inner wall of the piston sleeve 4 is provided with an embedding groove 14 for embedding the locking pin 12. In the normal state, the locking pin 12 is retracted in the guide sleeve 8 and does not interfere with the axial movement of the piston sleeve 4 pushed by the electric push rod 5. In the trigger state, the locking pin 12 is driven by the electromagnetic lock 7 to pop out radially and is inserted into the embedding groove 14 in the inner wall of the piston sleeve 4, so as to mechanically lock the nut sleeve 3 and the piston sleeve 4.

[0034] In the initial state, the right end of the nut sleeve 3 abuts against the inner wall of the piston sleeve 4. At this time, the screw rod 2 rotates to drive the nut sleeve 3 to move axially through thread transmission. The nut sleeve 3 further pushes the piston sleeve 4 to move axially synchronously. In this process, the locking pin 12 and the embedding groove 14 in the inner wall of the piston sleeve 4 are always in a misaligned state.

[0035] After the motor fails, the screw rod 2 and the nut sleeve 3 remain relatively stationary due to the thread self-locking characteristic. The nut sleeve 3 cannot move axially any more. At this time, the electric push rod 5 is started, and the extension end of the electric push rod 5 pushes the piston sleeve 4 to move axially alone. The displacement amount of this movement is consistent with the displacement amount required for the brake pad to press the brake disc. That is, when the electric push rod 5 pushes the piston sleeve 4 to the position where the brake pad and the brake disc interact to achieve braking, the embedding groove 14 in the inner wall of the piston sleeve 4 is radially aligned with the locking pin 12.

[0036] The advantage of the above design is that the structure of the screw rod 2, the nut sleeve 3 and the piston sleeve 4 is directly used as a mounting carrier without the need for additional independent cavities, which simplifies the overall structure. The locking point directly acts between the nut sleeve 3 and the piston sleeve 4, reducing intermediate transmission loss and improving locking response efficiency. At the same time, the original transmission parameters (such as pitch and lead) of the screw rod 2 and the nut sleeve 3 are not changed, avoiding the influence on the original transmission system. Relying on the existing machining process (such as deep hole drilling), conventional technical personnel can complete production and manufacturing without additional investment in new technology.

[0037] The hollow structure of the guide sleeve 8 is composed of a spring cavity 9 and a guide cavity 10 connected in communication, the top block at the end of the moving iron core of the electromagnetic lock 7 is located in the spring cavity 9, and a pre-tightening spring 11 is further arranged in the spring cavity 9, the pre-tightening spring 11 is sleeved outside the locking pin 12, the two ends of the pre-tightening spring 11 are fixedly connected with the wall surface of the spring cavity 9 and the surface of the locking pin 12 respectively, the pre-tightening spring 11 is in a pre-tightening state, the elastic force of the pre-tightening spring 11 pulls back and keeps the locking pin 12 in the guide cavity 10, when the electromagnetic lock 7 is powered on, the moving iron core pushes the top block, the top block presses the locking pin 12 to move outward along the guide cavity 10, so that the locking pin 12 is embedded in the embedding groove 14 of the piston sleeve 4 (at the same time, the pre-tightening spring 11 is further compressed), the locking and fixing of the piston sleeve 4 are realized, the locking pin 12 and the guide cavity 10 adopt H7 / g6 clearance fit (the clearance is 0.02-0.05mm), and the matching surfaces are injected with solid lubricating grease with a temperature resistance range of-40℃~120℃.

[0038] The space between the nut sleeve 3 and the piston sleeve 4 is arranged with a wireless module, a wireless receiving chip and a relay are in patch packaging, and are integrated on a PCB plate in the space, the PCB plate is electrically connected with the electromagnetic lock 7 through a wire, and the electric push rod 5 also has a wireless module, the module is specially matched with the electric push rod 5, and is used for realizing wireless control and signal transmission of the electric push rod 5.

[0039] The locking pin 12 is made of 40Cr material and has a cylindrical shape as a whole, the outer end close to the piston sleeve 4 is provided with a hemispherical head, so as to reduce the resistance when being inserted into the embedding groove 14, and the bottom of the embedding groove 14 is designed in a circular arc transition, which is matched with the hemispherical head of the locking pin 12.

[0040] The electromagnetic lock 7 is a DC miniature push-repulsion type electromagnetic lock, the top block at the end of the moving iron core of the electromagnetic lock 7 is in abutting fit with the end face of the inner end (the side away from the piston sleeve 4) of the locking pin 12, so as to ensure stable transmission of the pushing action.

[0041] The specific implementation is as follows: standby state (initial state): the screw rod 2, the nut sleeve 3 and the piston sleeve 4 in the brake caliper body 1 are in the initial assembly position, the right end of the nut sleeve 3 is in close abutment with the inner wall of the piston sleeve 4; the electromagnetic lock 7 is powered off, the relay is disconnected, the top block at the end of the moving iron core is retracted, the locking pin 12 is retracted in the guide cavity 10 of the guide sleeve 8 under the pre-tightening pulling force of the pre-tightening spring 11, and is not in contact with the inner wall of the piston sleeve 4, the electric push rod 5 is retracted in the axial cavity of the screw rod 2, the extension end is not extended out of the extension hole 6, the brake pad is in a separated state from the brake disc, and the wireless modules are all in a signal standby state.

[0042] Normal parking brake operation (normal motor): when the vehicle needs to be parked, the system performs the normal brake process, which relies on the "motor, planetary gear mechanism" drive transmission. When power is input, the motor starts with the planetary gear mechanism, output torque drives the lead screw 2 to rotate around its axis, the lead screw 2 drives the nut sleeve 3 to move axially along the lead screw 2 axis towards the brake pad, the nut sleeve 3 synchronously pushes the piston sleeve 4 to slide axially, one end of the piston sleeve 4 directly pushes the brake pad, making the brake pad and the brake disc tightly pressed, generating parking brake force, and completing parking.

[0043] Emergency brake trigger operation (motor failure): when the motor fails and the normal parking brake transmission system cannot work, the emergency brake is started by the electric push rod 5, the process is as follows: after the motor fails, the system remotely controls the electric push rod 5 in the cavity of the lead screw 2, the extension end of the electric push rod 5 extends from the extension hole 6 at the right end of the lead screw 2, the extension end of the electric push rod 5 directly pushes the piston sleeve 4, making the piston sleeve 4 move axially alone towards the brake pad, when the electric push rod 5 pushes the piston sleeve 4 to the position where the brake pad contacts the brake disc and generates brake force, the embedded groove 14 on the inner wall of the piston sleeve 4 is radially aligned with the locking pin 12.

[0044] Emergency brake locking trigger operation: after the embedded groove 14 is aligned with the locking pin 12, the system starts mechanical locking to ensure the stability of the emergency brake state, after the electromagnetic lock 7 is powered on, its moving iron core drives the end block to move towards the locking pin 12, the block is in contact with the inner end face of the locking pin 12, pushing the locking pin 12 to slide radially outward along the guide cavity 10 of the guide sleeve 8, and inserting into the embedded groove 14 on the inner wall of the piston sleeve 4, completing the mechanical locking of the nut sleeve 3 and the piston sleeve 4.

[0045] Mechanical locking maintenance operation: after locking, the system enters the continuous braking state, the locking pin 12 and the embedded groove 14 form a rigid fit, directly limiting the axial return movement of the piston sleeve 4, avoiding displacement of the piston sleeve 4 due to brake reaction force, the position of the piston sleeve 4 is fixed, and the pushing force of the piston sleeve 4 on the brake pad is continuously applied, keeping the brake pad and the brake disc in a stable and tightly pressed state, and the vehicle meets the safety parking requirements under the action of the brake force.

[0046] Reset operation (after the motor returns to normal): when the motor is removed, the system returns to standby state, disconnects the power supply of electromagnetic lock 7, resets the moving iron core and the top block, separates from the inner end of locking pin 12, releases the energy storage of pre-tightening spring 11, generates elastic tension, pulls locking pin 12 back into the guide cavity 10 of guide sleeve 8, separates locking pin 12 from embedded groove 14, controls the wireless module in control screw 2, triggers the contraction of the extension end of electric push rod 5, and returns from the state of pushing piston sleeve 4 to the cavity of screw 2. After piston sleeve 4 loses the pushing force of electric push rod 5, the reverse tension of the return spring installed on the brake piece drives the brake piece and piston sleeve 4 to retreat along the axial direction until the right end of nut sleeve 3 again abuts against the inner wall of piston sleeve 4, restores the initial position, and the brake piece and brake disc are separated again.

[0047] While embodiments of the present application have been shown and described, it is to be understood that the embodiments described are merely divergences, modifications, replacements and variations of the embodiments, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An electronically controlled parking brake caliper, comprising a brake caliper body (1), a screw rod (2), a nut sleeve (3) and a piston sleeve (4), characterized in that: The screw rod (2) is provided with a cavity along its own axis, and an electric push rod (5) is installed in the cavity; the right end of the screw rod (2) is provided with an expansion hole (6), the expansion hole (6) is used for the expansion end of the electric push rod (5) to extend out and push the piston sleeve (4), the outer surface of the nut sleeve (3) is provided with a mounting groove (13), the mounting groove (13) is provided with an electromagnetic lock (7), the surface of the nut sleeve (3) is provided with a locking pin (12) matched with the electromagnetic lock (7), and the inner wall of the piston sleeve (4) is provided with an embedding groove (14) for embedding the locking pin (12). The surface of the electromagnetic lock (7) is fixedly connected with a guide sleeve (8) arranged in the radial direction of the nut sleeve (3), the guide sleeve (8) is a hollow structure with openings at both ends, and the locking pin (12) is slidingly connected in the guide sleeve (8).

2. An electronically controlled parking brake caliper according to claim 1, wherein, The screw rod (2) is rotatably connected with the brake caliper body (1), the nut sleeve (3) is sleeved on the outer periphery of the screw rod (2) and is engaged with the screw rod (2) through threads, the piston sleeve (4) is sleeved on the outer periphery of the nut sleeve (3) and is connected with the nut sleeve (3) through splines and realizes axial sliding, and the right end of the nut sleeve (3) abuts against the inner wall of the piston sleeve (4).

3. An electronically controlled parking brake caliper according to claim 1, wherein, The hollow structure of the guide sleeve (8) is composed of a spring cavity (9) and a guide cavity (10) connected in communication, and the top block at the end of the moving iron core of the electromagnetic lock (7) is located in the spring cavity (9).

4. An electronically controlled parking brake caliper according to claim 3, wherein, The spring cavity (9) is further provided with a pre-tightening spring (11), the pre-tightening spring (11) is sleeved on the outside of the locking pin (12), and the two ends of the pre-tightening spring (11) are fixedly connected with the wall surface of the spring cavity (9) and the surface of the locking pin (12) respectively.

5. An electronically controlled parking brake caliper according to claim 1 wherein, A first wireless module is integrated in the space between the nut sleeve (3) and the piston sleeve (4), the first wireless module is electrically connected with the electromagnetic lock (7), the electric push rod (5) has a second wireless module, and the second wireless module cooperates with the electric push rod (5) to realize wireless control and signal transmission.

6. An electronically controlled parking brake caliper according to claim 1 wherein, The outer end of the locking pin (12) close to the piston sleeve (4) is provided with a hemispherical head, and the bottom of the embedding groove (14) is provided with a circular arc transition bottom surface matched with the hemispherical head of the locking pin (12).

7. An electronically controlled parking brake caliper according to claim 1 wherein, The top block at the end of the moving iron core of the electromagnetic lock (7) is matched with the end face of the inner end of the locking pin (12).

8. An electronically controlled parking brake caliper according to claim 1 wherein, When the motor fails, the electric push rod (5) pushes the piston sleeve (4) to the position where the brake pad is pressed against the brake disc, and the embedding groove (14) in the inner wall of the piston sleeve (4) is radially aligned with the locking pin (12).

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