Electronic parking brake caliper dedicated to parking brake

Abstract

The present invention discloses an electronic parking brake caliper specially used for parking brake. The outer brake block and the inner brake block are respectively installed on the main caliper body and the auxiliary caliper body, the connecting plate is fixedly installed on the rear axle, the main caliper body is provided with a guide hole for the caliper body guide pin and the caliper body guide pin sleeve to pass through, the caliper body guide pin sleeve is sleeved in the guide hole of the main caliper body, the caliper body guide pin passes through the caliper body guide pin sleeve and is connected to the threaded hole of the connecting plate by thread, thereby connecting the main caliper body and the connecting plate; a caliper body return spring is connected between the end of the caliper body guide pin away from the connecting plate and the main caliper body, so that the main caliper body moves elastically along the caliper body guide pin axial direction. The present invention adopts a bracket-free structure, which achieves the purpose of zero drag of the brake caliper, lightweight, simple structure and good product assembly processability.

Description

Technical Field

[0001] The invention relates to an electronic parking brake caliper, in particular to an electronic parking brake caliper specially used for parking brake. Background Art

[0002] For some models that have high requirements for rear axle driving braking force and need to have parking function, the solution of installing a single opposed multi-piston fixed caliper or floating caliper cannot meet the requirements of driving braking force and parking braking force at the same time. Therefore, a dual caliper design scheme emerges, one of which is an opposed multi-piston fixed caliper, dedicated to driving braking, and the other is a floating caliper, dedicated to parking braking.

[0003] An existing electronic parking brake caliper specifically used for parking brake is based on a conventional bracket fixing and caliper body floating structure, removing the oil inlet hole and bleed screw related to the hydraulic brake system, and retaining the caliper body, bracket, piston, inner and outer brake block assemblies, parking mechanism and actuator. When parking, the actuator drives the parking mechanism to push the piston, and the piston moves axially, pushing the inner brake block assembly to press the inner working surface of the brake disc, thereby causing the caliper body to move and push the outer brake block assembly to press the outer working surface of the brake disc to achieve parking. When releasing parking, the actuator drives the parking mechanism in reverse to release the pressure, and the piston retreats axially under the rebound force of the rectangular sealing ring, and the parking brake is released. This structure is similar to the existing floating caliper structure for driving and parking, and only requires minor changes. However, this also makes it inevitable that a series of problems existing in the floating caliper for driving and parking will also appear in the simplified parking brake caliper, such as 1. The bracket and caliper body have complex structures, and the guide pins and caliper body pin holes require high precision matching, and the processing cost is high; 2. The parking mechanism has a complex structure, many parts, and high assembly requirements; 3. After the parking brake is released, the brake pad and piston cannot be completely returned to the initial position, causing the brake disc and brake pad to drag, resulting in unnecessary wear of the friction material and loss of vehicle driving force.

[0004] Another existing electronic parking brake caliper specifically used for parking brakes removes the bracket on the basis of the previous structure, further simplifies the structure, and the caliper body is directly mounted on the connecting plate through a guide pin. When parking, the actuator drives the parking mechanism to push the piston, and the piston moves axially, pushing the inner brake pad assembly to press the inner working surface of the brake disc, thereby causing the caliper body to move along the guide pin and drive the outer brake pad assembly to press the outer working surface of the brake disc to achieve parking. When releasing the parking, the actuator drives the parking mechanism in reverse to release the pressure, and the piston is axially retracted by the rebound force of the rectangular sealing ring, and the parking brake is released. This structure simplifies the casting, processing, and assembly processes and reduces costs, but there are also problems that the brake pads and pistons cannot accurately return to the initial position after the parking brake is released, and the drag torque is too large. Summary of the invention

[0005] The purpose of the present invention is to provide an electronic parking brake caliper dedicated to parking brake to solve the problems of large drag torque, rapid wear of brake pads, complex structure, poor product assembly processability, etc. of the existing electronic parking brake caliper dedicated to parking brake.

[0006] The technical solution adopted by the patent of this invention is:

[0007] The present invention comprises a connecting plate, a main caliper body, an auxiliary caliper body, a caliper body guide pin, a caliper body guide pin sleeve, a caliper body return spring, a brake block guide pin, an outer brake block, an inner brake block, a connecting mechanism, a piston and a screw; the caliper body comprises a main caliper body and an auxiliary caliper body, the outer brake block and the inner brake block are respectively mounted on the main caliper body and the auxiliary caliper body, the connecting plate is fixedly mounted on the rear axle, the main caliper body is provided with a guide hole for the caliper body guide pin and the caliper body guide pin sleeve to pass through, the caliper body guide pin sleeve is sleeved in the guide hole of the main caliper body, the caliper body guide pin passes through the caliper body guide pin sleeve and is connected to the threaded hole of the connecting plate through a thread, thereby connecting the main caliper body and the connecting plate; the end of the caliper body guide pin away from the connecting plate is connected to the main caliper body There is a caliper body return spring, which makes the main caliper body move elastically along the axial direction of the caliper body guide pin; the main caliper body is processed with a mounting hole on the end face away from the connecting plate, and the main caliper body is processed with a piston hole on the end face close to the connecting plate. The mounting hole and the piston hole are coaxially connected through a connecting hole. The piston is installed in the piston hole. A piston sealing ring is provided between the outer wall of the piston and the inner wall of the piston hole of the main caliper body, which is sealed by the piston sealing ring. The piston sealing ring adopts an O-ring. The piston is processed with an internal threaded hole on the end face away from the connecting plate, one end of the screw is processed with an external thread and passes through the mounting hole and the connecting hole of the main caliper body and is screwed into the internal threaded hole of the piston to match. The other end of the screw extends out of the mounting hole of the main caliper body, and the middle part of the screw and the connecting hole of the main caliper body are connected. The two are connected by a sleeve and a sealing ring, and a flange flange disk is processed in the middle of the screw located in the piston hole. The step formed between the connecting hole of the main caliper body and the piston hole is connected to the flange flange disk through two anti-friction gaskets and a needle bearing, so that the screw assembly is connected to the main caliper body; pin threaded holes are provided on both sides of the piston hole of the main caliper body, and brake block guide pins are threadedly installed in the pin threaded holes of the main caliper body. The inner brake block is installed on the optical axis section of the brake block guide pin and moves locally along the axial direction of the brake block guide pin shaft; a center hole is processed on the end face of the piston close to the connecting plate, and the hole wall of the center hole is processed into an arc to form an inner circular groove, and notches are provided on the end faces of the pistons on both sides symmetrically around the center hole to form two trapezoidal grooves. ; The inner brake block is provided with two cylindrical bosses and a connecting mechanism on the end face close to the piston. The connecting mechanism includes a base and a spring ball head plunger. The base is riveted and fixed to the center of the end face of the inner brake block. The two cylindrical bosses are symmetrically fixed on both sides of the base. The base protrudes from the end face of the inner brake block. The surrounding surface of the base is provided with a plurality of radial holes evenly spaced along the circumferential direction. A spring ball head plunger is installed in each radial hole. The end of the spring ball head plunger and the bottom of the radial hole are connected by a spring. Under the action of the spring, the spring ball head plunger moves radially and is embedded in the inner circular groove of the piston; the two cylindrical bosses are respectively embedded in the two trapezoidal grooves of the piston to limit the rotation of the piston.

[0008] The connection between the inner brake pad and the piston through the connecting mechanism is a movable connection, the axial relative displacement of the inner brake pad relative to the piston axis is between 0-0.05mm, and the radial relative displacement of the inner brake pad relative to the piston is between 0-1mm.

[0009] Both ends of the caliper body guide pin are provided with caliper body guide pin dust covers for dust prevention. One caliper body guide pin dust cover is sleeved outside the caliper body guide pin sleeve between one end of the caliper body guide pin away from the connecting plate and the main caliper body, and the other caliper body guide pin dust cover is sleeved outside the caliper body guide pin sleeve between one end of the caliper body guide pin close to the connecting plate and the connecting plate.

[0010] The main clamp body is provided with a positioning boss around the guide hole for positioning and limiting the return movement distance of the main clamp body, and the positioning boss is used for contacting and connecting the end face of the connecting plate.

[0011] The surface of the positioning boss is sprayed with a polyurethane damping coating, which is used to alleviate the impact force on the connecting plate when the main clamp body returns and reduce the incidental noise.

[0012] Two annular anti-friction gaskets are respectively installed on the step between the connecting hole of the main caliper body and the piston hole and the step surface of the flange flange plate, and the screw between the two anti-friction gaskets is covered with a needle bearing.

[0013] The caliper return spring is always in a compressed state, and the spring force is between 10-300N.

[0014] An annular notch groove is provided between the inner edge hole end and the inner wall of the piston hole of the main caliper body, and a piston dust cover is provided at the annular notch groove, and the piston dust cover is used to prevent external dust and impurities from entering.

[0015] The auxiliary caliper body is fixedly connected to the main caliper body by bolts. A groove is processed on a side E of the auxiliary caliper body close to the main caliper body. The outer brake block is interference-fitted in the groove of the auxiliary caliper body. Two through holes are processed in the groove.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. By machining the internal thread in the piston so that it can directly cooperate with the screw, on the one hand, the screw sleeve can be omitted and the parts can be reduced. On the other hand, the moving distance and direction of the piston can be accurately controlled by controlling the number of rotations and the direction of rotation of the screw, so that the piston can quickly return to the initial position when the parking brake is released.

[0018] 2. Since the piston is returned by the threaded cooperation between the screw and the piston, the rectangular sealing ring that originally plays the role of piston return and sealing can be replaced with an O-ring that only has a sealing function, which can reduce costs and reduce the sliding resistance of the piston.

[0019] 3. Connect the inner brake pad to the piston through a connecting mechanism so that the piston can drive the inner brake pad to move, ensuring that the inner brake pad is completely disengaged from the brake disc without drag after the brake is released.

[0020] 4. By combining the caliper body return spring and the caliper body positioning boss, when the brake is released, the caliper body moves along the guide pin under the action of the return spring force until the positioning boss contacts the connecting plate and stops, thereby ensuring that the outer brake block fixed on the auxiliary caliper body is completely disengaged from the brake disc without drag.

[0021] Since the inner and outer brake pads can be completely disengaged from the brake disc without drag after the brake is released, the amount of brake pad wear caused by the parking brake is very small. Therefore, the thickness of the brake pad friction material can be greatly reduced, the piston length can be shortened, and the total volume and total mass of the brake caliper can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. The drawings show:

[0023] Figure 1 It is an axial view of the assembly of the present invention.

[0024] Figure 2 It is a cross-sectional view of the assembly of the present invention.

[0025] Figure 3 This is a cross-sectional view of the guide pin position of the caliper body of the present invention.

[0026] Figure 4 This is a cross-sectional view of the main clamp body of the present invention.

[0027] Figure 5 This is a sectional view of the piston position of the present invention.

[0028] Figure 6 It is a cross-sectional view of the inner brake pad belt connection mechanism of the present invention.

[0029] Figure 7 This is a view of the inner brake pad with connecting mechanism and piston shaft of the present invention.

[0030] Figure 8 This is a static hysteresis curve diagram obtained by testing an embodiment of the present invention.

[0031] In the figure, 1. connecting plate, 2. main caliper body, 3. auxiliary caliper body, 4. caliper body guide pin dust cover, 5. outer brake block, 6. inner brake block, 7. connecting mechanism, 8. piston dust cover, 9. piston sealing ring, 10. piston, 11. screw, 12. anti-friction washer, 13. needle bearing, 14. caliper body guide pin sleeve, 15. caliper body guide pin, 16. caliper body return spring, 17. brake block guide pin, 18. connecting mechanism base, 19. spring ball head plunger, 20. positioning boss, 21. inner circle groove, 22. cylindrical boss, 23. trapezoidal groove. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1-Figure 5 As shown, the electronic parking brake caliper assembly of the present invention includes a connecting plate 1, a main caliper body 2, an auxiliary caliper body 3, a caliper body guide pin 15, a caliper body guide pin sleeve 14, a caliper body return spring 16, a brake pad guide pin 17, an outer brake pad 5, an inner brake pad 6, a connecting mechanism 7, a piston 10, and a screw 11.

[0034] like Figure 2 , Figure 3 As shown, the caliper body includes a main caliper body 2 and an auxiliary caliper body 3, an outer brake block 5 and an inner brake block 6 are respectively installed on the main caliper body 2 and the auxiliary caliper body 3, and a space for a brake disc is provided between the outer brake block 5 and the inner brake block 6, as shown in FIG. Figure 1 , Figure 2 As shown, the auxiliary caliper body 3 is fixedly connected to the main caliper body 2 by bolts, and a groove is processed on a side E of the auxiliary caliper body 3 close to the main caliper body 2. The outer brake block 5 is interference fitted in the groove of the auxiliary caliper body, and two through holes for disassembling the outer brake block 5 are processed in the groove.

[0035] The connecting plate 1 is fixedly mounted on the rear axle, and the main caliper body 2 is provided with a guide hole for the caliper body guide pin 15 and the caliper body guide pin sleeve 14 to penetrate. Figure 4 As shown, a guide hole is opened on each side of the main caliper body 2, and the caliper body guide pin sleeve 14 is sleeved in the guide hole 24 of the main caliper body 2. The caliper body guide pin 15 passes through the caliper body guide pin sleeve 14 and is connected to the threaded hole of the connecting plate 1 through a thread, thereby connecting the main caliper body 2 and the connecting plate 1; a caliper body return spring 16 is connected between the end of the caliper body guide pin 15 away from the connecting plate 1 and the main caliper body 2, and the caliper body return spring 16 is sleeved outside the caliper body guide pin sleeve 14 and the two ends are respectively connected to the end of the caliper body guide pin 15 and the main caliper body 2, so that the main caliper body 2 moves along the axial direction (positive and negative directions of X) of the caliper body guide pin 15.

[0036] Both ends of the caliper body guide pin 15 are provided with caliper body guide pin dust covers 4 for dust prevention. One caliper body guide pin dust cover 4 is sleeved on the outside of the caliper body guide pin sleeve 14 between one end portion of the caliper body guide pin 15 away from the connecting plate 1 and the main caliper body 2, and the other caliper body guide pin dust cover 4 is sleeved on the outside of the caliper body guide pin sleeve 14 between one end portion of the caliper body guide pin 15 close to the connecting plate 1 and the connecting plate 1; that is, a caliper body guide pin dust cover 4 and a caliper body return spring 16 are installed between one end face A of the caliper body guide pin 15 and one end face B of the caliper body guide pin hole, and a caliper body guide pin dust cover 4 is installed between one end face D of the caliper body guide pin sleeve 14 and one end face C of the caliper body guide hole.

[0037] like Figure 4 As shown, the main caliper body 2 is provided with a positioning boss 20 around the guide hole 24 for positioning and limiting the return movement distance of the main caliper body 2, and the positioning boss 20 is used to contact the end face of the connecting plate 1. In the specific implementation, the caliper body return spring 16 is always in a compressed state, the initial spring force is 10N, and the spring force is 200N when the parking brake is applied. After the parking brake is released, the spring 16 pushes the main caliper body 2 to move in the positive direction of the X direction close to the connecting plate 1 until the positioning boss 20 of the main caliper body contacts the connecting plate 1, thereby ensuring that the main caliper body 2 returns to the initial position and realizes the return of the main caliper body 2.

[0038] The surface of the positioning boss 20 is sprayed with a polyurethane damping coating to alleviate the impact force on the connecting plate 1 when the main clamp body returns and reduce the incidental noise.

[0039] like Figure 2 As shown, the main caliper body 2 is processed with a mounting hole on the end face away from the connecting plate 1, and the main caliper body 2 is processed with a piston hole on the end face close to the connecting plate 1. The mounting hole and the piston hole are coaxially connected through a connecting hole, and the aperture of the connecting hole is smaller than the apertures of the mounting hole and the piston hole. The piston 10 is installed in the piston hole. The piston sealing ring 9 is different from the rectangular sealing ring used in existing similar products, and an O-type sealing ring is used. The piston return is changed from the existing similar products that are achieved by elastic deformation of the rectangular sealing ring to being directly driven by the screw to return. Only the O-type sealing ring is needed to play a sealing role and no return role is needed.

[0040] A piston seal ring 9 is provided between the outer wall of the piston 10 and the inner wall of the piston hole of the main caliper body 2, and the piston seal ring 9 is used for sealing. Specifically, an annular groove is provided on the inner wall of the piston hole of the main caliper body 2, and the piston seal ring 9 is installed in the annular groove.

[0041] An annular notch groove is provided between the inner edge hole end and the inner wall of the piston hole of the main caliper body 2, and a piston dust cover 8 is provided at the annular notch groove. The piston dust cover 8 is used to prevent external dust and impurities from entering.

[0042] The piston 10 is processed with an internal threaded hole on the end face away from the connecting plate 1, and one end of the screw rod 11 is processed with an external thread and passes through the mounting hole and the connecting hole of the main caliper body 2 and is screwed into the internal threaded hole of the piston 10 for matching. The other end of the screw rod 11 extends out from the mounting hole of the main caliper body 2, and the middle part of the screw rod 11 and the connecting hole of the main caliper body 2 are connected through a sleeve and a sealing ring, and a flange flange is processed in the middle part of the screw rod 11 located in the piston hole, and the step formed between the connecting hole of the main caliper body 2 and the piston hole is connected to the flange flange through two anti-friction gaskets 12 and a needle bearing 13, so that the screw rod 11 is assembled and connected to the main caliper body 2. Specifically, as Figure 2 As shown, two annular anti-friction gaskets 12 are respectively installed on the step between the connecting hole and the piston hole of the main caliper body 2 and the step surface of the flange flange plate, and the screw 11 between the two anti-friction gaskets 12 is set with a needle bearing 13, and the two ends of the needle bearing 13 are connected to the two anti-friction gaskets 12.

[0043] like Figure 4 As shown, pin threaded holes are provided on both sides of the piston hole of the main caliper body 2, and brake pad guide pins 17 are threadedly installed in the pin threaded holes of the main caliper body 2. The inner brake pad 6 is installed on the brake pad guide pin 17 through bosses with through holes on both sides. There is a movable optical axis on the brake pad guide pin 17, and the inner brake pad 6 can be partially movable axially on this section of the optical axis. The inner brake pad 6 moves axially (positive and negative directions of X) along the brake pad guide pin axis 17.

[0044] like Figure 5 and Figure 7 As shown, the piston 10 is processed with a center hole on the end face close to the connecting plate 1, the middle hole wall of the center hole is processed into an arc to form an inner circular groove 21, and the end faces of the piston 10 on both sides symmetrically around the center hole are notched to form two trapezoidal grooves 23.

[0045] like Figure 6 and Figure 7 As shown, the inner brake block 6 is provided with two cylindrical bosses 22 and a connecting mechanism 7 at the end face close to the piston 10. The connecting mechanism 7 includes a base 18 and a spring ball plunger 19. The base 18 is riveted and fixed to the center of the end face of the inner brake block 6. The two cylindrical bosses 22 are symmetrically fixed and arranged on both sides of the base 18. The base 18 protrudes from the end face of the inner brake block 6. The surrounding surface of the base 18 is provided with a plurality of radial holes evenly spaced along the circumferential direction. A spring ball plunger 19 is installed in each radial hole. The end of the spring ball plunger 19 and the bottom of the radial hole are connected by a spring. Under the action of the spring, the spring ball plunger 19 moves radially and is embedded in the inner circular groove 21 of the piston 10. The two cylindrical bosses 22 are respectively embedded in the two trapezoidal grooves 23 of the piston 10 to limit the rotation of the piston 10. The above structure makes the connection between the inner brake block and the piston through the connecting mechanism a movable connection.

[0046] The connection mechanism 7 uses the spring ball plunger 19 to clamp the inner groove of the piston 10, so that the inner brake block 6 is axially fixedly connected to the piston 10 and can be movably disassembled. The connection mechanism 7 limits the axial relative displacement and radial relative displacement between the inner brake block and the piston. The axial relative displacement is between 0-0.05mm, which is determined by the difference between the outer diameter of the spring ball plunger and the outer diameter of the inner groove of the piston, and the radial relative displacement is between 0-1mm. Mainly considering that during braking, the brake block has the same displacement along the direction of rotation of the disc, and the design of a movable connection can prevent the brake block from transmitting the displacement to the piston in the form of force.

[0047] When connecting and installing the piston 10 and the inner brake pad 6, it is only necessary to align the base 18 of the inner brake pad 6 with the center hole of the piston 10, align the two cylindrical bosses 22 of the inner brake pad 6 with the two trapezoidal grooves 23 of the piston 10, and then press the inner brake pad 6 to move toward the piston 10, so that the four spring ball head plungers 19 are first contracted and then extended into the inner circular grooves 21, so that the piston 10 and the inner brake pad 6 are coaxially connected.

[0048] The external power drives the screw 11 to rotate, and the guiding and limiting effect of the threaded pair and the piston hole on the piston 10 drives the piston 10 to move axially along the screw 11, thereby driving the inner brake block 6 to move away from or close to the outer brake block 5, thereby achieving braking and releasing the brake.

[0049] In a specific implementation, the brake caliper structure of the present invention is subjected to a static drag test, and the data obtained are as shown in the following table, and the continuous curve obtained is as shown in the following table. Figure 8 As shown:

[0050] Static drag data

[0051] First lap Lap 10 Torque N·m 0.27 <0.05

[0052] It can be seen from the above table and graph data that the static drag of the present invention is greatly reduced, and the static drag measured data and curve show that the drag torque is approximately zero, and the effect is stable.

[0053] Therefore, the present invention solves the technical problems of the existing electronic parking brake caliper specially used for parking brake, such as large drag torque, rapid wear of brake pads, complex structure, and poor product assembly processability. By adopting a bracket-free structure, combined with a brake pad and a piston connection mechanism, the internal thread of the piston and the screw, the interference fit of the outer brake pad and the caliper return spring, the purpose of zero drag, lightweight, simple structure and good product assembly processability of the brake caliper is achieved.

Claims

1. An electronic parking brake caliper specially used for parking brake, characterized in that: The invention comprises a connecting plate (1), a main caliper body (2), an auxiliary caliper body (3), a caliper body guide pin (15), a caliper body guide pin sleeve (14), a caliper body return spring (16), a brake block guide pin (17), an outer brake block (5), an inner brake block (6), a connecting mechanism (7), a piston (10) and a screw rod (11); the caliper body comprises a main caliper body (2) and an auxiliary caliper body (3); the outer brake block (5) and the inner brake block (6) are respectively mounted on the main caliper body (2) and the auxiliary caliper body (3); the connecting plate (1) is fixedly mounted on the rear axle; the main caliper body (2) is provided with a guide hole for the caliper body guide pin (15) and the caliper body guide pin sleeve (14) to penetrate; the caliper body guide pin sleeve (14) is sleeved on the main caliper body (2) and the auxiliary caliper body (3); In the guide hole (24) of the caliper body (2), a caliper body guide pin (15) passes through the caliper body guide pin sleeve (14) and is connected to the threaded hole of the connecting plate (1) through a thread, thereby connecting the main caliper body (2) and the connecting plate (1); a caliper body return spring (16) is connected between an end of the caliper body guide pin (15) away from the connecting plate (1) and the main caliper body (2), so that the main caliper body (2) moves elastically along the axial direction of the caliper body guide pin (15); a mounting hole is machined on the end face of the main caliper body (2) away from the connecting plate (1), and a piston hole is machined on the end face of the main caliper body (2) close to the connecting plate (1); the mounting hole and the piston hole are coaxially connected through a connecting hole, and the piston (10) is installed in the piston hole. A piston seal ring (9) is provided between the outer wall of the piston (10) and the inner wall of the piston hole of the main caliper body (2). The piston seal ring (9) is an O-ring. The piston (10) is processed with an internal threaded hole at the end face away from the connecting plate (1). One end of the screw rod (11) is processed with an external thread and passes through the mounting hole and the connecting hole of the main caliper body (2) and is screwed into the internal threaded hole of the piston (10) for matching. The other end of the screw rod (11) extends out from the mounting hole of the main caliper body (2). The middle part of the screw rod (11) and the connecting hole of the main caliper body (2) are connected through a shaft sleeve and a seal ring. A flange flange is processed at the middle part of the screw rod (11) located in the piston hole. A step is formed between the connecting hole of the main caliper body (2) and the piston hole. The flange flange plate is connected to the piston (10) via two anti-friction washers (12) and a needle bearing (13), so that the screw rod (11) is assembled and connected to the main caliper body (2); pin threaded holes are provided on both sides of the piston hole of the main caliper body (2), a brake block guide pin (17) is threadedly installed in the pin threaded hole of the main caliper body (2), and the inner brake block (6) is installed on the optical axis section of the brake block guide pin (17) and moves locally along the axial direction of the brake block guide pin shaft 17; the piston (10) is processed with a center hole on the end surface close to the connecting plate (1), the hole wall of the center hole is processed into an arc to form an inner circular groove (21), and the end surfaces of the piston (10) on both sides symmetrically around the center hole are notched to form two trapezoidal grooves (23);The inner brake block (6) is provided with two cylindrical bosses (22) and a connecting mechanism (7) on the end surface close to the piston (10). The connecting mechanism (7) includes a base (18) and a spring ball plunger (19). The base (18) is riveted and fixed to the center of the end surface of the inner brake block (6). The two cylindrical bosses (22) are symmetrically fixedly arranged on both sides of the base (18). The base (18) protrudes from the end surface of the inner brake block (6). The peripheral surface of the base (18) is provided with a plurality of radial holes evenly spaced in the circumferential direction, each radial hole being provided with a spring ball plunger (19), the end of the spring ball plunger (19) being connected to the bottom of the radial hole by a spring, the spring ball plunger (19) being radially telescopically moved under the action of the spring, and being embedded in the inner circular groove (21) of the piston (10); two cylindrical bosses (22) being respectively embedded in the two trapezoidal grooves (23) of the piston (10), for limiting the rotation of the piston (10). ; 2. The electronic parking brake caliper specifically used for parking brake according to claim 1, characterized in that: The connection between the inner brake block (6) and the piston (10) formed by the connection mechanism (7) is a movable connection, the axial relative displacement of the inner brake block (6) relative to the axis of the piston (10) is between 0 and 0.05 mm, and the radial relative displacement of the inner brake block (6) relative to the piston (10) is between 0 and 1 mm.

3. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: Both ends of the caliper body guide pin (15) are provided with caliper body guide pin dust covers (4) for preventing dust. One caliper body guide pin dust cover (4) is sleeved outside the caliper body guide pin sleeve (14) between one end of the caliper body guide pin (15) away from the connecting plate (1) and the main caliper body (2), and the other caliper body guide pin dust cover (4) is sleeved outside the caliper body guide pin sleeve (14) between one end of the caliper body guide pin (15) close to the connecting plate (1) and the connecting plate (1).

4. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: The main clamp body (2) is provided with a positioning boss (20) around the guide hole (24) for positioning and limiting the return movement distance of the main clamp body (2), and the positioning boss (20) is used to contact and connect with the end surface of the connecting plate (1).

5. The electronic parking brake caliper dedicated to parking brake according to claim 4, characterized in that: The surface of the positioning boss (20) is sprayed with a polyurethane damping coating, which is used to alleviate the impact force on the connecting plate (1) when the main clamp body returns to its original position and reduce the incidental noise.

6. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: Two annular anti-friction gaskets (12) are respectively mounted on the step between the connecting hole and the piston hole of the main caliper body (2) and the step surface of the flange flange plate, and a needle bearing (13) is mounted on the screw (11) between the two anti-friction gaskets (12).

7. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: The caliper body return spring (16) is always in a compressed state, and the spring force is between 10-300N.

8. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: An annular notch groove is provided between the inner edge hole end and the inner wall of the piston hole of the main caliper body (2), and a piston dust cover (8) is provided at the annular notch groove. The piston dust cover (8) is used to prevent external dust and impurities from entering.

9. The electronic parking brake caliper dedicated to parking brake according to claim 1, characterized in that: The auxiliary caliper body (3) is fixedly connected to the main caliper body (2) by means of bolts. A groove is machined on a side surface (E) of the auxiliary caliper body (3) close to the main caliper body (2). The outer brake block (5) is interference-fitted in the groove of the auxiliary caliper body. Two through holes are machined in the groove.

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