Electronic control type parking brake caliper

Abstract

The invention 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 installed in the cavity, and a telescopic hole is formed in the right end of the lead screw; a telescopic hole is formed in the outer surface of the nut sleeve, the telescopic end of the electric push rod extends out of the telescopic hole and pushes the piston sleeve, a mounting groove is formed in the outer surface of the nut sleeve, an electromagnetic lock is mounted in the mounting groove, a locking pin matched with the electromagnetic lock is arranged on the surface of the nut sleeve, and an embedding groove allowing the locking pin to be embedded is formed in the inner wall of the piston sleeve. The invention aims to solve the problem that an existing electronic parking brake system is usually driven by a motor to realize the parking locking function after the vehicle is stably parked and the parking releasing function before the vehicle is started, and if the motor suddenly fails, calipers cannot be driven to complete the clamping action, so that the vehicle is difficult to stably park.

Description

Technical Field

[0001] The present invention relates to the technical field of brake calipers, in particular to an electronically controlled parking brake caliper. Background Art

[0002] At present, in the field of motor vehicle brake system manufacturing technology, especially in the actuator of the vehicle electronic parking brake system, the structural form of an actuator with an electronic parking brake system is a brake caliper actuator integrated with the rear caliper. The rear caliper integrated brake caliper actuator is composed of a motor, a deceleration mechanism and a brake caliper. For the rear caliper integrated brake caliper actuator, the vehicle electronic parking brake system actuator in the prior art includes a transmission device and a brake caliper assembly. The output of the DC motor in the transmission device is decelerated and torque-increased by a synchronous belt transmission mechanism and an involute small-tooth-difference planetary gear transmission mechanism, and the sliding screw transmission mechanism converts the rotational motion into linear motion, and the brake disc is braked by using a screw sleeve to push the piston and brake pad assembly.

[0003] The existing publication number: CN120207295B discloses an electronic mechanical brake parking mechanism and control method, which belongs to the field of vehicle braking, including a reduction motor and a brake caliper, a locking disk fixed on the motor shaft of the reduction motor, an electromagnetic locking assembly is arranged inside the motor housing of the reduction motor and at the position corresponding to the locking disk, the locking head of the electromagnetic locking assembly corresponds to the locking hole opened on the locking disk, a parking position sensor is arranged inside the motor housing, and a magnet that cooperates with the parking position sensor is fixed on the end face side of the locking disk; a locking position sensor is also arranged inside the motor housing for detecting the forward and backward movements of the locking head, the locking position sensor and the parking position sensor are both electrically connected to the controller, and the controller is electrically connected to the reduction motor.

[0004] There is also publication number: CN101722945B which 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 a semi-enclosed area formed by an upper cover and a shell, and the transmission mechanism assembly is connected to the brake caliper assembly. An emergency release mechanism is provided in the transmission mechanism assembly, and the end of the emergency release mechanism extends to the outside of the shell. The extended end of the emergency release mechanism can be connected to power to enable the transmission mechanism assembly to transmit power.

[0005] Existing electronic parking brake systems are usually driven by a motor to achieve the parking lock function after the vehicle is stopped and the parking release function before starting. When the controller receives the vehicle parking brake command issued by the vehicle controller, it controls the motor to rotate forward, driving the brake caliper to clamp through the transmission mechanism until the set clamping force is generated. However, if the motor suddenly fails, it will be unable to drive the caliper to complete the clamping action, making it difficult to park the vehicle stably. Summary of the Invention

[0006] The purpose of the present invention is to provide an electronically controlled parking brake caliper to solve the problem that the existing electronic parking brake system is usually driven by a motor to achieve the parking lock function after the vehicle is stopped and the parking release function before starting. If the motor suddenly fails, it will be unable to drive the caliper to complete the clamping action, making it difficult to park the vehicle stably.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An electronically controlled parking brake caliper comprises a brake caliper body, a screw, a nut sleeve and a piston sleeve. The screw has a cavity along its own axis, in which an electric push rod is installed. A telescopic hole is provided at the right end of the screw, and the telescopic hole allows the telescopic end of the electric push rod to extend and push the piston sleeve. A mounting groove is provided on the outer surface of the nut sleeve, in which an electromagnetic lock is installed. A locking pin that cooperates with the electromagnetic lock is provided on the surface of the nut sleeve, and an embedding groove for embedding the locking pin is provided on the inner wall of the piston sleeve.

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

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

[0011] Preferably, a guide sleeve arranged radially along the nut sleeve is fixedly connected to the surface of the electromagnetic lock, 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 consists of a spring cavity and a guide cavity that are connected to each other, 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 preload spring is further provided in the spring cavity. The preload spring is sleeved on the outside of the locking pin, and two ends of the preload spring are fixedly connected to the wall surface of the spring cavity and the surface of the locking pin respectively.

[0014] The preload force of the preload spring keeps the locking pin in the guide cavity; when the electromagnetic lock is energized, the moving iron core pushes the top block to compress the preload spring and drive 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 to the electromagnetic lock, and a second wireless module is provided in the electric push rod, and the second wireless module cooperates with the electric push rod to realize wireless control and signal transmission.

[0016] Preferably, the outer end of the locking pin close to the piston sleeve is set as a hemispherical head, and the bottom of the embedding groove is set as an arc transition bottom surface, which is adapted to the hemispherical head of the locking pin.

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

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

[0019] Compared with the prior art, the present invention 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 completing the contact between the brake pad and the brake disc to achieve emergency braking. When the piston sleeve moves to the braking position, the electromagnetic lock on the nut sleeve will drive the locking pin to accurately embed into the embedding groove of the piston sleeve, forming a mechanical locking structure. This effectively prevents the piston sleeve from retreating due to the braking reaction force, ensuring continuous and stable emergency braking force, and completely solving the core problems of being unable to park after motor failure and the easy failure of emergency braking force.

[0021] 2. Regarding structural simplicity, the design eliminates the need for an additional independent cavity. Instead, it fully utilizes the structural space within the existing brake caliper components. The electric push rod is built into the screw shaft cavity, and a mounting slot is provided on the outer surface of the nut sleeve to accommodate the electromagnetic lock. This highly integrated design simplifies the overall structural layout and avoids the structural bloat that would be caused by the addition of an emergency mechanism.

[0022] 3. In terms of control convenience, intelligent control is achieved through the built-in wireless module. The wireless modules integrated in the gap between the nut sleeve and the piston sleeve and inside the screw rod can wirelessly control the electromagnetic lock and the electric push rod respectively. There is no need for complicated wired wiring, and the signal transmission is stable. It not only makes the triggering of emergency braking and locking more convenient, but also adapts to the vehicle's intelligent control needs and improves the flexibility of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the overall section of the present invention;

[0024] Figure 2 This is a schematic structural diagram of the cross-section of the screw rod, nut sleeve, and piston sleeve of the present invention;

[0025] Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle;

[0026] Figure 4 It is a schematic structural diagram of the guide sleeve of the present invention.

[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 chamber; 10. Guide chamber; 11. Preload spring; 12. Locking pin; 13. Mounting slot; 14. Embedded slot. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] See also Figures 1 to 4 , the present invention provides a technical solution.

[0030] An electronically controlled parking brake caliper includes 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 into the brake caliper body 1. The screw rod 2 is rotatably connected to 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 a thread. The piston sleeve 4 is sleeved on the outer periphery of the nut sleeve 3 and is connected to the nut sleeve 3 through a spline to achieve axial sliding. The end of the piston sleeve 4 away from the nut sleeve 3 abuts against the 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. When parking, the motor cooperates with the planetary gear mechanism to drive the screw rod 2 to rotate. The rotation of the screw rod 2 drives the nut sleeve 3 to move along its axial direction, and then pushes the piston sleeve 4. The piston sleeve 4 then pushes the brake pad, so that the brake pad is pressed against the brake disc, and finally completes the parking brake.

[0032] A cavity is opened along the axis of the screw rod 2, and an electric push rod 5 is installed in the cavity. A telescopic hole 6 is opened at the right end of the screw rod 2, which allows the telescopic end of the electric push rod 5 to extend, and after the telescopic end is extended, it can push the piston sleeve 4 to move axially. The above structure is used to deal with emergency scenarios of automobile motor failure. When the motor of the electronic parking brake caliper fails, the electric push rod 5 can be started to extend its telescopic end, and the telescopic end pushes the piston sleeve 4, thereby driving the brake pad and brake disc to be pressed together, realizing emergency braking and ensuring that the vehicle can be parked.

[0033] An outer surface of the nut sleeve 3 is provided with a mounting groove 13, and an electromagnetic lock 7 is installed in the mounting groove 13. A locking pin 12 that cooperates with the electromagnetic lock 7 is provided on the surface of the nut sleeve 3. The surface of the electromagnetic lock 7 is fixedly connected to a guide sleeve 8 arranged radially along the nut sleeve 3. The guide sleeve 8 is a hollow structure with openings at both ends. The locking pin 12 is slidably connected to the guide sleeve 8. The inner wall of the piston sleeve 4 is provided with an embedding groove 14 for the locking pin 12 to be embedded. 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 electric push rod 5 to push the piston sleeve 4. In the triggered state, the locking pin 12 is driven by the electromagnetic lock 7 to pop out radially and insert into the embedding groove 14 on the inner wall of the piston sleeve 4 to realize mechanical locking of 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, driving the nut sleeve 3 to move axially through the threaded transmission, and the nut sleeve 3 further pushes the piston sleeve 4 to move axially synchronously with it. During this process, the locking pin 12 and the embedded groove 14 on 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 self-locking characteristics of the thread, and the nut sleeve 3 can no longer move axially. At this time, the electric push rod 5 is started, and its telescopic end pushes the piston sleeve 4 to move axially alone. The displacement of this movement is consistent with the displacement 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 brake disc interact to achieve braking", the embedded groove 14 on the inner wall of the piston sleeve 4 is exactly radially aligned with the locking pin 12.

[0036] The advantage of the above design is that the structure of the screw rod 2, nut sleeve 3 and piston sleeve 4 is directly used as the installation carrier, without the need to set up an additional independent cavity, thus simplifying the overall structure; and the locking point acts directly between the nut sleeve 3 and the piston sleeve 4, reducing intermediate transmission losses and improving the 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 impact on the original transmission system; relying on existing processing technology (such as deep hole drilling), conventional technicians can complete production and manufacturing without the need for additional investment in new processes.

[0037] The hollow structure of the guide sleeve 8 consists of a connected spring chamber 9 and a guide chamber 10. The top block at the end of the moving iron core of the electromagnetic lock 7 is located in the spring chamber 9. A preload spring 11 is also provided in the spring chamber 9. The preload spring 11 is sleeved on the outside of the locking pin 12, and its two ends are fixedly connected to the wall of the spring chamber 9 and the surface of the locking pin 12 respectively. The preload spring 11 is in a preloaded state, and its elastic force pulls the locking pin 12 back and holds it in the guide chamber 10. When the electromagnetic lock 7 is energized, the moving iron core pushes the top block, pressing the locking pin 12 to move outward along the guide chamber 10, so that it is embedded in the embedding groove 14 of the piston sleeve 4 (at the same time further compressing the preload spring 11), thereby realizing the locking and fixation of the piston sleeve 4. The locking pin 12 and the guide chamber 10 adopt an H7 / g6 clearance fit (clearance 0.02-0.05mm), and the fitting surface is injected with solid grease with a temperature resistance range of -40℃~120℃.

[0038] A wireless module is placed in the space between the nut sleeve 3 and the piston sleeve 4. The wireless receiving chip and relay are packaged in a patch package and integrated on a PCB board in the space. The PCB board is electrically connected to the electromagnetic lock 7 through a wire. Similarly, the electric push rod 5 also has a wireless module. This module is specifically used to cooperate with the electric push rod 5 to realize wireless control and signal transmission of the electric push rod 5.

[0039] The locking pin 12 is made of 40Cr material and is cylindrical as a whole. Its outer end close to the piston sleeve 4 is set as a hemispherical head to reduce the resistance when inserted into the embedding groove 14. The bottom of the embedding groove 14 adopts an arc transition design to match the hemispherical head of the locking pin 12.

[0040] The electromagnetic lock 7 uses a DC micro-repulsion electromagnetic lock, and the top block at the end of its moving iron core fits the inner end (away from the side of the piston sleeve 4) of the locking pin 12 to ensure stable transmission of the pushing action.

[0041] The specific implementation is as follows: standby state (initial state): the screw rod 2, nut sleeve 3, and piston sleeve 4 in the brake caliper body 1 are in the initial assembly position, and the right end of the nut sleeve 3 is in close contact with the inner wall of the piston sleeve 4; the electromagnetic lock 7 is powered off, the relay is disconnected from the power supply, and the top block at the end of its moving iron core is retracted. Under the preload tension of the preload spring 11, the locking pin 12 is retracted into the guide cavity 10 of the guide sleeve 8, and has no contact with the inner wall of the piston sleeve 4. The electric push rod 5 is retracted into the axial cavity of the screw rod 2, and the telescopic end does not extend out of the telescopic hole 6. The brake pad and the brake disc are in a separated state, and the wireless modules are all in a signal standby state.

[0042] Conventional parking brake operation (motor is normal): When the vehicle needs to be parked, the system executes the conventional braking process. The core relies on the "motor and planetary gear mechanism" to drive the transmission. When power is input, the motor cooperates with the planetary gear mechanism to start, and the output torque drives the screw 2 to rotate around its own axis. The screw 2 drives the nut sleeve 3 to move axially along the axis of the screw 2 toward the brake pad through threaded engagement. The nut sleeve 3 simultaneously pushes the piston sleeve 4 to slide axially. One end of the piston sleeve 4 directly pushes the brake pad, so that the brake pad and the brake disc are tightly pressed, generating parking braking force to complete parking.

[0043] Emergency brake triggering operation (motor failure): When the motor fails, the conventional parking transmission system cannot work. At this time, the electric push rod 5 is started for emergency braking. The process is as follows: After the motor fails, the system remotely controls the triggering of the electric push rod 5 in the cavity of the screw rod 2. Its telescopic end extends from the telescopic hole 6 at the right end of the screw rod 2. The telescopic end of the electric push rod 5 directly pushes the piston sleeve 4, causing the piston sleeve 4 to move axially toward the brake pad alone. When the electric push rod 5 pushes the piston sleeve 4 to the position where the brake pad contacts the brake disc and generates braking 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 lock triggering operation: When the embedding groove 14 is aligned with the locking pin 12, the system starts mechanical locking to ensure that the emergency braking state is stable. After the electromagnetic lock 7 is energized, its moving iron core drives the end top block to move toward the locking pin 12. The top block fits with the inner end surface 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 inserts into the embedding 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 holding operation: After locking is completed, the system enters a continuous braking state, and the locking pin 12 forms a rigid fit with the embedded groove 14, directly limiting the axial retraction movement of the piston sleeve 4, avoiding the displacement of the piston sleeve 4 due to the braking reaction force. The position of the piston sleeve 4 is fixed, and its thrust on the brake pad continues to act, so that the brake pad and the brake disc remain in a stable and tight state, and the vehicle meets the safe parking requirements under the action of braking force.

[0046] Reset operation (after the motor returns to normal): When the motor fault is eliminated and returns to normal, the system performs a reset and returns to the standby state. First, the power supply of the electromagnetic lock 7 is disconnected, the moving iron core and the top block are reset, and the inner end of the locking pin 12 is disengaged. The preloaded spring 11 releases the stored energy, generating elastic tension, pulling the locking pin 12 back into the guide cavity 10 of the guide sleeve 8, and the locking pin 12 is completely separated from the embedded groove 14. The wireless module in the control screw 2 triggers the telescopic end of the electric push rod 5 to retract, and return from the state of pushing the piston sleeve 4 to the cavity of the screw 2. After the piston sleeve 4 loses the pushing force of the electric push rod 5, the return spring installed on the brake pad generates a reverse pulling force, driving the brake pad and the piston sleeve 4 to retreat axially until the right end of the nut sleeve 3 abuts against the inner wall of the piston sleeve 4 again, restoring the initial position, and the brake pad and the brake disc are separated again.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention 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) has a cavity along its own axis, and an electric push rod (5) is installed in the cavity. A telescopic hole (6) is provided at the right end of the screw rod (2), and the telescopic end of the electric push rod (5) extends out of the telescopic hole (6) and pushes the piston sleeve (4). The outer surface of the nut sleeve (3) has a mounting groove (13), and an electromagnetic lock (7) is installed in the mounting groove (13). The surface of the nut sleeve (3) is provided with a locking pin (12) that matches the electromagnetic lock (7), and the inner wall of the piston sleeve (4) has an embedding groove (14) for the locking pin (12) to be embedded.

2. The electronically controlled parking brake caliper according to claim 1, characterized in that: The screw rod (2) is rotatably connected to 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 a thread; the piston sleeve (4) is sleeved on the outer periphery of the nut sleeve (3) and is connected to the nut sleeve (3) through a spline to achieve axial sliding; the right end of the nut sleeve (3) abuts against the inner wall of the piston sleeve (4).

3. The electronically controlled parking brake caliper according to claim 1, characterized in that: The surface of the electromagnetic lock (7) is fixedly connected to a guide sleeve (8) arranged radially along the nut sleeve (3). The guide sleeve (8) is a hollow structure with openings at both ends. The locking pin (12) is slidably connected in the guide sleeve (8).

4. The electronically controlled parking brake caliper according to claim 3, characterized in that: The hollow structure of the guide sleeve (8) consists of a spring cavity (9) and a guide cavity (10) that are connected to each other, and the top block at the end of the moving iron core of the electromagnetic lock (7) is located in the spring cavity (9).

5. The electronically controlled parking brake caliper according to claim 4, characterized in that: A preload spring (11) is also provided in the spring cavity (9). The preload spring (11) is sleeved on the outside of the locking pin (12), and its two ends are fixedly connected to the wall surface of the spring cavity (9) and the surface of the locking pin (12), respectively.

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

7. The electronically controlled parking brake caliper according to claim 1, characterized in that: The outer end of the locking pin (12) close to the piston sleeve (4) is configured as a hemispherical head, and the bottom of the embedding groove (14) is configured as an arc transition bottom surface, which is adapted to the hemispherical head of the locking pin (12).

8. The electronically controlled parking brake caliper according to claim 1, characterized in that: The top block at the end of the moving iron core of the electromagnetic lock (7) fits snugly with the inner end surface of the locking pin (12).

9. The electronically controlled parking brake caliper according to claim 1, characterized in that: When the motor fails and the electric push rod (5) pushes the piston sleeve (4) to a position where the brake pad presses the brake disc, the embedding groove (14) on the inner wall of the piston sleeve (4) is radially aligned with the locking pin (12).

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