Brake caliper

Abstract

The present invention discloses a brake caliper including an actuator, a brake caliper body, a motion conversion mechanism, and an adjustment member disposed in the flow of axial force transmission between the actuator and a brake disc. The adjustment member is operably connected to a counter member so that the motion conversion mechanism has degrees of freedom for adjustment in terms of rotation angle and radial displacement. The brake caliper of the present invention includes the adjustment member, which provides the motion conversion mechanism with adjustment space for rotation angle and radial displacement, thereby eliminating the effects of braking tangential force, brake pad wear, and caliper body deformation on the motion conversion mechanism. This makes it possible to extend the service life of the motion conversion mechanism.

Description

[Technical Field]

[0001] The present invention is in the technical field of braking systems, and more particularly, the present invention relates to brake calipers. [Background technology]

[0002] As vehicles shift to electrification, brake-by-wire systems are becoming a major growth trend in the automotive industry. One such system, the electromechanical brake (EMB) system, uses a direct drive system from the wheel-mounted motor. In this system, a motion conversion mechanism converts the torque and rotational motion of the motor into the pushing force and translational movement of a connecting member, which pushes and moves the brake pads to clamp the brake disc, thereby generating braking force. This system has advantages such as simple layout, quick response, and high efficiency.

[0003] In the prior art, EMB systems have not yet been widely used in vehicles. This is due to the following reasons: First, motion conversion mechanisms that meet the application requirements are expensive and have complex structures, making them unsuitable for mass production (e.g., planetary roller screws, tilting mechanisms, etc.). Second, motion conversion mechanisms that meet the cost and production process requirements are unable to adapt to the complex operating conditions of service brakes and have insufficient service life (e.g., ball screws, sliding screws, etc.). For example, in the case of ball screws, to meet the braking capacity requirements, the outer diameter of the ball screw is usually designed to be very large to resist axial forces. However, ball screws are still prone to malfunction in service brake systems. The reasons are as follows:

[0004] 1. When braking, ball screws are subjected not only to axial forces but also to radial forces. This is one of the causes of ball screws losing their functionality. In a vehicle's braking system, the brake disc rotates along with the wheel. Therefore, when braking, the brake pads are also subjected to a tangential force from the brake disc. The transmission of this force to the ball screw is equivalent to applying a radial force to the ball screw. When a radial force is applied to the output end of the ball screw, a moment is generated that tilts the ball screw around a certain point. This moment is called an overturning moment. The overturning moment causes a misalignment between the axis of the nut and the screw shaft. This results in the force being applied to only a few balls, resulting in ball crushing or permanent deformation of the thread groove.

[0005] 2. Due to the floating caliper structure, the caliper body may deform due to the reaction force of the brake clamping force, causing the axis of the cylinder bore in the caliper body to tilt. Normally, as the caliper body deforms, the axis of the screw shaft also tilts, but the axis of the nut tends to remain perpendicular to the plane of the brake pad or brake disc. This causes a misalignment between the screw shaft and the axis of the nut. This misalignment causes uneven axial load distribution across the cross section of the ball screw, which in turn causes uneven Hertzian contact stress acting on the balls, resulting in a loss of function of the ball screw.

[0006] Patent Document 1 proposes a solution to the above problem: forming an arch-shaped connecting surface between the piston and the nut, creating a contact pattern similar to a circular arc, thereby compensating for the misalignment between the piston axis and the ball screw axis. However, Patent Document 1 only considers the deformation of the caliper body and does not consider the effects of brake pad wear. The tangential force generated during braking also deforms the caliper body relative to the frame. This deformation results in a difference in the amount of wear at the brake pad's rotation inlet and outlet ends, known as brake pad wear. This condition also causes a misalignment between the piston axis and the ball screw axis. Because the direction of this misalignment is perpendicular to the direction of the misalignment caused by the caliper body deformation, the structure of Patent Document 1 cannot adjust or compensate for it.

[0007] To address the above-mentioned issues, Patent Document 2 proposes a structure that forms conical contact between the screw shaft and flange, and between the nut and piston. This structure also allows for adjustment and compensation for misalignment between the axis of the piston and the axis of the ball screw. However, Patent Document 2 requires the diameter of the ball screw to be increased to meet the load capacity requirements. This increases the diameter of the conical surface, which increases the length of the moment arm of the overturning moment, resulting in a problem of a larger overturning moment being supported.

[0008] Second, there is a significant limitation on the space available on a vehicle for arranging brake calipers. The front wheels have a drive system, and the drive shaft oscillates left and right when turning, and also oscillates up and down when passing over a depression. Therefore, the lower the axial height of the brake caliper, the better, and the more compact its structure. Patent Document 3 uses a hollow ball screw, and by arranging the planetary gear inside the screw shaft and coaxially arranging the motor and cylinder bore, the structure is made very compact. However, the axial size is still large, and the above-mentioned issues regarding EMB placement are not completely resolved.

[0009] Therefore, the challenge is how to ensure the fatigue life of the motion conversion mechanism under operating conditions such as overturning moment, deformation of the caliper body, and brake pad wear, while also reducing the axial height of the brake caliper.

[0010] In summary, the problems existing in prior art brake calipers are as follows:

[0011] 1. The force acting on the motion conversion mechanism becomes too large or too uneven due to the tipping moment caused by the brake tangential force, deformation of the caliper body, and wear of the brake pads, causing the mechanism to lose function prematurely.

[0012] 2. When a conical contact structure is used, the diameter of the conical surface increases as the diameter of the ball screw increases, resulting in an increase in the radius of the friction torque and an increase in the supporting overturning moment.

[0013] 3. Because there is limited space for installing brake calipers on a vehicle, it is generally believed that the smaller the axial height, the better, but there is currently no effective solution. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Chinese Patent Application Publication No. 107076237 [Patent Document 2] U.S. Patent No. 8,607,939 [Patent Document 3] US Patent Application Publication No. 20050034936 Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention aims to solve at least one of the technical problems existing in the prior art, and therefore provides a brake caliper that aims to extend the service life of a motion conversion mechanism. [Means for solving the problem]

[0016] In order to achieve the above object, the technical means used in the present invention are as follows.

[0017] The brake caliper includes an actuator, a brake caliper body, a motion conversion mechanism, and an adjustment member disposed in the flow of axial force transmission between the actuator and the brake disc, the adjustment member being operably connected to a counter member such that the motion conversion mechanism has degrees of adjustment for rotation angle and / or radial displacement.

[0018] In some embodiments, the adjustment members form spherical pairs, conical pairs, planar pairs, or a combination of two of these with adjacent pairs.

[0019] In some embodiments, the adjustment member has two spherical surfaces at both ends and an intermediate portion located between the two spherical surfaces. The spherical surfaces at both ends of the adjustment member contact the adjacent pair members, respectively, to form a two-spherical pair mechanism.

[0020] In some embodiments, the intermediate portion of the adjustment member is divided into at least two engaging portions having different cross-sectional sizes, and the adjacent pair members engage with the two engaging portions of the intermediate portion, respectively, so that the adjacent pair members rotate synchronously.

[0021] In some embodiments, the brake caliper further includes a shaft coupling, wherein the actuator is connected to the motion conversion mechanism via the shaft coupling.

[0022] In some embodiments, the motion conversion mechanism includes a parallel moving member and a rotating member, the rotating member is connected to the shaft coupling, the adjustment member is disposed between the shaft coupling and the rotating member, and the adjustment member forms a spherical joint mechanism with the shaft coupling and the rotating member, respectively.

[0023] In some embodiments, the engagement portion has a non-cylindrical structure. The shaft coupling and the rotating member are connected via the adjusting member to achieve synchronous rotation.

[0024] In some embodiments, the engagement portion comprises a spline or a rectangular structure.

[0025] In some embodiments, the engaging portion has a cylindrical structure, and the coupling and the rotating member are connected by a spline or a rectangular structure to achieve synchronous rotation.

[0026] In some embodiments, the brake caliper further includes a piston, the motion conversion mechanism includes a parallel moving member and a rotational member, the adjustment member is disposed between the parallel moving member and the piston, and the adjustment member forms a spherical pair mechanism with the piston and the parallel moving member, respectively.

[0027] In some embodiments, a fixed connection between the coupling and the rotating member is formed by threading, riveting or welding, and an operable connection between the translation member and the piston is formed by a retaining ring.

[0028] In some embodiments, the piston has a cavity, the cavity completely houses the motion conversion mechanism, and an outer wall of the piston engages with a cylinder bore of the brake caliper body.

[0029] In some embodiments, the piston has a cavity, the cavity completely houses a portion of the motion conversion mechanism, and an outer wall of the translation member engages with a cylinder bore of the brake caliper body.

[0030] In some embodiments, a radial spring is attached between the translation member and the piston.

[0031] In some embodiments, the engaging portion has a non-cylindrical structure. The translation member and the piston are connected via the adjustment member to achieve synchronous axial movement.

[0032] In some embodiments, the engagement portion comprises a spline or a rectangular structure.

[0033] In some embodiments, an anti-rotation mechanism is provided between the translation member and the brake caliper body or between the piston and the brake caliper body.

[0034] In some embodiments, an elastic ring and a dust cover are attached between the parallel moving member and the cylinder bore of the brake caliper body, or between the piston and the cylinder bore of the brake caliper body.

[0035] In some embodiments, the brake caliper further includes a bearing, wherein the bearing and the two-spherical pair mechanism are disposed inside the translation member or the piston.

[0036] In some embodiments, a position restriction mechanism that fits to each other is provided between the rotation member and the translation member. [Effects of the Invention]

[0037] The brake caliper of the present invention is provided with an adjustment member to provide the motion conversion mechanism with adjustment space for the rotation angle and radial displacement, thereby eliminating the effects of braking tangential force, brake pad wear, and caliper body deformation on the motion conversion mechanism, thereby extending the service life of the motion conversion mechanism. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is a schematic diagram of the overall structure of a brake caliper according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing how force is applied when the caliper body is deformed or the brake pad is worn in the first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing how a radial force is applied in the first embodiment. [Figure 4] FIG. 4 is a schematic structural diagram of a two-spherical pair mechanism in the second embodiment. [Figure 5] FIG. 5 is a schematic diagram of the overall structure of a brake caliper according to the third embodiment. [Figure 6] FIG. 6 is a schematic structural diagram of a two-spherical pair mechanism in the fourth embodiment. [Figure 7] FIG. 7 is a schematic structural diagram of the adjustment member in Examples 1 and 3. [Figure 8] FIG. 8 is a schematic structural diagram of the adjustment member in Examples 2 and 4. DETAILED DESCRIPTION OF THE INVENTION

[0039] Next, specific embodiments of the present invention will be described in more detail by describing examples with reference to the drawings, for the purpose of helping those skilled in the art to more completely, accurately and deeply understand the concept and technical means of the present invention and to facilitate implementation.

[0040] Below, we will discuss two spherical joint mechanisms as examples. As shown in FIGS. 1 to 5, the present invention provides a brake caliper mainly including a brake caliper body 3, an actuator 1, an inner brake pad 16, an outer brake pad 18, and a motion conversion mechanism 4. The actuator 1 includes at least a motor and a deceleration / torque amplification mechanism. The motion conversion mechanism 4 is disposed within a cylinder bore of the brake caliper body 3. The torque and rotational motion supplied from the motor are transmitted to the motion conversion mechanism 4 via the deceleration / torque amplification mechanism, and are converted into a pushing force and linear motion of the parallel moving member 4b, which pushes and moves the brake pads, thereby clamping the brake disc 17. The adjustment member 8 is disposed in the flow of axial force transmission between the actuator 1 and the brake disc 17. The adjustment member 8 and its surrounding pair members form a two-spherical pair mechanism.

[0041] The brake caliper provided by the present invention has the following advantages:

[0042] 1.2 By using the spherical joint mechanism, the influence of the overturning moment, brake pad wear, deformation of the caliper body, etc. on the motion conversion mechanism 4 can be eliminated, thereby extending the service life of the motion conversion mechanism 4.

[0043] In the present invention, an egg-shaped adjustment member 8 is used. Both ends of the adjustment member 8 are spherical. The middle part of the adjustment member 8 is cylindrical or has a structure that can realize other functions (for example, a polyhedron, a rectangular shape, a spline, or the like that can transmit torque). The adjustment member 8 is disposed in the flow of axial force transmission between the actuator 1 and the brake disc 17. Furthermore, the adjustment member 8 forms a spherical pair with each of the adjacent pair members, thereby forming a two-spherical pair mechanism. Compared to a single-spherical pair mechanism, the two-spherical pair mechanism in the present invention has the characteristic of not only having a degree of freedom in rotation angle but also a degree of freedom in radial displacement.

[0044] Taking the case where the motion conversion mechanism is a ball screw pair as an example, in the present invention, the adjustment member 8 can be disposed between the shaft coupling 2 and the screw shaft. The portions of the shaft coupling 2 and the screw shaft that come into contact with the adjustment member 8 are both spherical. Therefore, the adjustment member 8 and the shaft coupling 2, and the adjustment member 8 and the screw shaft all constitute spherical pairs.

[0045] (1) Method to eliminate the effect of overturning moment: In conventional technology, when the ball screw pair receives a superimposed load of axial and radial forces, an overturning moment occurs that rotates around one of the points. This causes a misalignment between the axis of the screw shaft and the nut, which causes the gaps between the inner and outer threads and the screw grooves to no longer match, and as a result, force is applied only to some of the balls, resulting in a loss of function.

[0046] In the present invention, when a radial force of the ball screw resulting from a braking tangential force acts on the parallel translation member 4b, the ball screw pair has a degree of freedom of radial displacement due to the actions of the adjustment member 8 and the shaft coupling 2, and the adjustment member 8 and the position restriction mechanism 4c. Therefore, the entire ball screw pair moves to the other side of the cylinder bore of the caliper body. As a result, the axis of the shaft coupling 2 remains unchanged and the adjustment member 8 tilts by a certain angle, but torque transmission is still possible. Furthermore, a relative horizontal displacement occurs between the axis of the ball screw pair and the axis of the shaft coupling 2. Then, when the outer wall of the parallel translation member 4b contacts the inner wall of the cylinder bore, the radial force is transmitted to the caliper body and converted into deformation of the caliper body. However, during this process, the axes of the rotation member 4a and the parallel translation member 4b always remain aligned, and the axial and radial load distribution of the ball screw pair is uniform, so no loss of function occurs.

[0047] (2) Method for eliminating the effects of brake pad wear: In conventional technology, the axis of the screw shaft generally always remains aligned with the axis of the cylinder bore in the caliper body, while the axis of the nut tends to remain perpendicular to the plane of the brake pad. Therefore, when the brake pad wears and the amount of wear is large on one side and small on the other, the axis of the nut tilts, causing a misalignment between the axis of the nut and the axis of the screw shaft. This causes uneven axial load distribution on the cross section of the ball screw pair, resulting in a loss of function.

[0048] In the present invention, the shaft coupling 2 receives the rotational speed and torque transmitted from the actuator 1. The axis of the shaft coupling 2 always coincides with the axis of the cylinder bore in the brake caliper body 3. The shaft coupling 2 transmits the rotational speed and torque to the rotating member 4a through the adjustment member 8. The adjustment function of the two-spherical joint mechanism allows the axes of the rotating member 4a or the parallel moving member 4b to have a certain tilt angle. Furthermore, if the parallel moving member 4b tilts due to brake pad wear, the rotating member 4a can also tilt along with the parallel moving member 4b. Furthermore, the tilt angle of the adjustment member 8 is greater than the tilt angle of the parallel moving member 4b caused by brake pad wear. Therefore, the axis of the rotating member 4a can always tilt along with the axis of the parallel moving member 4b, and the torque transmission function from the shaft coupling 2 to the rotating member 4a is not affected. This ensures uniform axial load distribution on the ball screw pair, preventing loss of function.

[0049] (3) Method to eliminate the effects of caliper body deformation: In conventional technology, when the nut acts as an output member to push and move the inner brake pad, the reaction force of the axial force is transmitted to the caliper body, causing the caliper body to deform. The axis of the nut tends to remain perpendicular to the plane of the brake pad, but the axis of the rotating member 4a tilts as the caliper body deforms, causing a misalignment between the axis of the nut and the axis of the rotating member 4a. This causes uneven axial load distribution on the cross section of the ball screw pair, resulting in a loss of function.

[0050] In the present invention, when the axis of the coupling 2 tilts due to deformation of the caliper body, the adjustment member 8 first tilts by a certain angle, but the rotating member 4a does not tilt along with the coupling 2 and tends to maintain overlap with the axis of the parallel movement member 4b. Furthermore, the angle at which the adjustment member 8 can tilt is greater than the tilt angle of the coupling 2 caused by deformation of the brake caliper body 3. Therefore, the axis of the rotating member 4a can always tilt in conjunction with the axis of the parallel movement member 4b. This ensures uniform load distribution in the axial direction of the ball screw pair, preventing loss of function.

[0051] 2. The radius of the spherical pair is small, reducing the deflection radius and therefore the overturning moment.

[0052] In the present invention, the spherical pair is formed by one adjustment member 8 and one pair member, so the radius of the spherical pair can be made very small regardless of the diameter size of the ball screw. This reduces the deflection radius when receiving a radial force, making it possible to reduce the overturning moment.

[0053] 3. The axial length is reduced by arranging each part in an overlapping manner in the axial direction to avoid occupying extra space.

[0054] In the present invention, the ball screw pair has a hollow structure, and parts such as the adjustment member 8 and bearings are placed inside the cavity of the rotating member 4a. This eliminates the need to occupy extra space in the axial direction, making it possible to minimize the axial length of the brake caliper.

[0055] In summary, in the present invention, by disposing the adjustment member 8 in the brake caliper, a two-spherical pair mechanism is formed in the flow of axial force transmission. This allows the motion conversion mechanism 4 to have degrees of freedom in terms of rotation angle and radial displacement, and the axes of the rotation member 4a and the translation member 4b of the motion conversion mechanism 4 tend to always maintain overlap during operation. As a result, uniform distribution of axial and radial loads is ensured, preventing loss of function due to force being applied to only a few balls and extending the service life of the motion conversion mechanism 4. Furthermore, the spherical radius of the adjustment member 8 can be designed to be sufficiently small, thereby reducing the deflection radius and overturning moment. Furthermore, by arranging each component inside a hollow screw, the axial height of the brake caliper is reduced. This allows the brake caliper of the present invention to withstand the influence of various factors during service brake operation, thereby ensuring the service life of the motion conversion mechanism 4. Furthermore, the reduced axial height of the brake caliper facilitates installation on a vehicle.

[0056] Next, a specific example will be described in combination. [Example]

[0057] As shown in FIGS. 1 to 3, the brake caliper of this embodiment includes a brake caliper body 3, an actuator 1, a motion converting mechanism 4, and an adjustment member 8.

[0058] The brake caliper body 3 has a floating caliper structure and includes a cylinder bore and a hook structure. An inner brake pad 16, a brake disc 17, and an outer brake pad 18 are mounted in this order within the hook structure. The actuator 1 includes a motor and a deceleration / torque amplification mechanism.

[0059] As shown in FIGS. 1 to 3, the motion conversion mechanism 4 includes a rotating member 4a and a parallel moving member 4b. In this embodiment, the motion conversion mechanism 4 is an internal circulation type ball screw. The rotating member 4a is a screw shaft, the parallel moving member 4b is a nut, and the parallel moving member 4b and the rotating member 4a form a ball screw pair. In addition, to transmit torque and rotational speed, the actuator 1 and the rotating member 4a are connected via a shaft coupling 2. A second bearing 10 is attached between the shaft coupling 2 and the brake caliper body 3. The second bearing 10 is a sliding bearing.

[0060] As shown in Figures 1 to 3, the adjustment member 8 has an egg-shaped structure. Both end surfaces of the adjustment member 8 are spherical. The adjustment member 8 is positioned in the flow of axial force transmission between the actuator 1 and the brake disc 17. The adjustment member 8, together with the pairing members, constitutes a two-spherical pairing mechanism via the spherical surfaces at both ends. In this embodiment, the pairing members are the shaft coupling 2 and the rotating member 4a. The adjustment member 8 provides the ball screw pair with degrees of freedom in terms of rotation angle around the spherical center of the spherical end surface of the adjustment member 8 and degrees of freedom in terms of radial displacement of the cylinder bore. The range over which the ball screw pair can be radially displaced relative to the shaft coupling 2 includes at least the radial displacement of the translation member 4b within the cylinder bore. The angle at which the ball screw pair can be tilted relative to the shaft coupling 2 or the rotating member 4a includes at least the maximum angle of tilt of the shaft coupling 2 due to deformation of the brake caliper body 3 and the maximum angle of tilt of the translation member 4b due to wear of the brake pads.

[0061] As shown in Figures 1 to 3 and 7, the adjustment member 8 is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends in the longitudinal direction. The spherical surfaces at both ends of the adjustment member 8 contact the adjacent pair members, respectively, to form a two-spherical pair mechanism. Relative deflection can occur between the adjustment member 8 and the pair member. The intermediate portion of the adjustment member 8 is divided into at least two engaging portions with different cross-sectional sizes. All engaging portions are arranged in sequence along the longitudinal direction of the intermediate portion. Adjacent pair members respectively engage with the two engaging portions of the intermediate portion. Furthermore, adjacent pair members rotate synchronously.

[0062] The intermediate portion of the adjustment member 8 may have a structure capable of transmitting torque, such as a polyhedron, spline, or rectangular shape. The adjustment member 8 has the function of transmitting torque between the shaft coupling 2 and the rotating member 4a. The shaft coupling 2 allows the rotating member 4a to rotate through the adjustment member 8. In this embodiment, as shown in FIG. 7, the engaging portion of the intermediate portion of the adjustment member 8 is hexahedral. Two engaging portions are provided, and the sizes of the two engaging portions are different. The centers of the engaging portions and the spherical cores of both end faces of the adjustment member 8 are located on the axis of the adjustment member 8. The shaft coupling 2 is provided inside with a first groove that accommodates the spherical end face of one end of the adjustment member 8 and a first inner hole that accommodates one of the engaging portions. The first inner hole is a hexagonal hole with the same shape as the engaging portion. A small gap exists between the inner wall surface of the first inner hole and the outer wall surface of the engaging portion. The rotating member 4a is provided with a second groove that accommodates the spherical end surface of the other end of the adjustment member 8 and a second inner hole that accommodates the other engaging portion. A small gap exists between the inner wall surface of the second inner hole and the outer wall surface of the engaging portion. The second inner hole is a hexagonal hole with the same shape as the engaging portion. The first and second grooves are spherical grooves. The size of the engaging portion that engages with the rotating member 4a is larger than the size of the engaging portion that engages with the shaft coupling 2. A wave spring 9 is attached between the adjusting member 8 and the rotating member 4a. The wave spring 9 is located in the second inner hole. The wave spring 9 is sandwiched between the engaging portion that engages with the rotating member 4a and the inner wall surface of the second inner hole. The wave spring 9 applies an axial elastic force to the rotating member 4a, urging the rotating member 4a to move axially toward a position away from the shaft coupling 2. As a result, the wave spring 9 can eliminate an axial gap between the shaft coupling 2 and the adjustment member 8 and maintain the adjustment member 8 in its restored state when no force is applied. The interior of the rotating member 4a has a square groove and a spherical surface. An annular groove is formed in the side wall, and a retaining ring 11 is attached in the annular groove. The retaining ring 11 fixes the shaft coupling 2 and the rotating member 4a relative to each other in the axial direction. The retaining ring 11 fixes the rotating member 4a and the shaft coupling 2 so that they are operably connected.

[0063] As shown in FIG. 1 , the brake caliper of this embodiment further includes an anti-rotation mechanism. The anti-rotation mechanism is provided between the parallel moving member 4b and the brake caliper body 3. The anti-rotation mechanism includes an anti-rotation screw 7 and a groove. The anti-rotation screw 7 is provided in the brake caliper body 3. The groove is provided on the outer wall of the parallel moving member 4b and extends in the axial direction of the parallel moving member 4b. The anti-rotation screw 7 is inserted into the groove to prevent the parallel moving member 4b from rotating in conjunction with the rotating member 4a. This allows the parallel moving member 4b to move linearly in the axial direction when the rotating member 4a rotates.

[0064] 1, a position restriction mechanism 4c that fits to the rotation member 4a and the parallel movement member 4b is provided between the rotation member 4a and the parallel movement member 4b. The position restriction mechanism 4c is used to prevent the parallel movement member 4b from getting stuck due to excessive rotation of the rotation member 4a.

[0065] As shown in Figure 1, the brake caliper of this embodiment further includes a first bearing 5. The first bearing 5 is a thrust needle bearing. The rotating member 4a has one open end and the other closed end, and is hollow inside. Since the first bearing 5 and the two spherical pair mechanisms are both disposed in the internal cavity of the rotating member 4a, the axial size of the caliper can be reduced.

[0066] As shown in Figure 1, an elastic ring 12 and a dust cover 13 are attached between the parallel moving member 4b and the cylinder bore of the brake caliper body 3 for sealing. The elastic ring 12 and the dust cover 13 are arranged in this order along the axial direction of the cylinder bore. The inner peripheries of the elastic ring 12 and the dust cover 13 are tightly fitted with the outer wall of the parallel moving member 4b. The elastic ring 12 and the dust cover 13 provide two support points for the parallel moving member 4b, so the parallel moving member 4b can maintain a coaxial state with the cylinder bore when rotating in and out. [Example]

[0067] As shown in Figures 4 and 8, the structure of the brake caliper provided in this embodiment differs from the structure of the brake caliper provided in Example 1 in the following respects. That is, in this embodiment, the middle portion of the adjustment member 8 has a cylindrical structure, and the engagement portion is also cylindrical. The adjustment member 8 does not have the function of transmitting torque between the shaft coupling 2 and the rotating member 4a. By connecting the end of the shaft coupling 2 to the rotating member 4a with a structure capable of transmitting torque, such as a spline or a rectangular shape, synchronous rotation of the shaft coupling 2 and the rotating member 4a is achieved.

[0068] Compared with Example 1, the brake caliper provided in this example has the advantage that the adjustment member 8 is removed from the torque transmission path, and the engagement size is reduced by one set, which reduces the overall backlash and reduces the risk of generating operating noise. [Example]

[0069] As shown in Figure 5, the structure of the brake caliper provided in this embodiment differs from that of the brake caliper provided in embodiment 1 in the following respects: the brake caliper provided in this embodiment further includes a piston 6. The piston 6 completely accommodates the ball screw pair. The outer wall of the piston 6 engages with the inner wall of the cylinder bore.

[0070] As shown in FIG. 5, the brake caliper of this embodiment includes a brake caliper body 3, an actuator 1, a piston 6, a motion conversion mechanism 4, and an adjustment member 8.

[0071] The brake caliper body 3 has a floating caliper structure and includes a cylinder bore and a hook structure. An inner brake pad 16, a brake disc 17, and an outer brake pad 18 are mounted in this order within the hook structure. The actuator 1 includes a motor and a deceleration / torque amplification mechanism. The structures of the brake caliper body 3 and the actuator 1 are similar to those known to those skilled in the art, and will not be described in detail here.

[0072] As shown in FIG. 5, the motion conversion mechanism 4 includes a rotating member 4a and a parallel moving member 4b. In this embodiment, the motion conversion mechanism 4 is an internal circulation type ball screw. The rotating member 4a is a screw shaft, the parallel moving member 4b is a nut, and the parallel moving member 4b and the rotating member 4a form a ball screw pair. In addition, to transmit torque and rotational speed, the actuator 1 and the rotating member 4a are connected via a shaft coupling 2. A second bearing 10 is attached between the shaft coupling 2 and the brake caliper body 3. The second bearing 10 is a sliding bearing. The piston 6 has one open end, the other closed end, and a hollow structure. The parallel moving member 4b is located completely within the internal cavity of the piston 6.

[0073] As shown in Figure 5, the parallel moving member 4b is hollow, has a recessed bottom, and has a groove and a spherical surface in the center. The piston 6 is hollow, has a protruding bottom, and is provided with a groove and a spherical surface. The adjustment member 8 is disposed between the parallel moving member 4b and the piston 6. The adjustment member 8 forms a spherical pair with the parallel moving member 4b and the piston 6, respectively, to form a two-spherical pair mechanism.

[0074] As shown in FIG. 5, the adjustment member 8 has an egg-shaped structure. The end faces of both ends of the adjustment member 8 are spherical. The adjustment member 8 is disposed in the flow of axial force transmission between the actuator 1 and the brake disc 17. The adjustment member 8, together with the pair members via the spherical surfaces at both ends, constitutes a two-spherical pair mechanism. In this embodiment, the pair members are the parallel moving member 4b and the piston 6.

[0075] The adjustment member 8 provides between the piston 6 and the ball screw pair a degree of freedom in terms of the rotation angle around the spherical center of the spherical end surface of the adjustment member 8 and a degree of freedom in terms of displacement in the radial direction of the cylinder bore. The range in which the piston 6 can be displaced radially relative to the ball screw pair includes at least the radial displacement of the piston 6 within the cylinder bore. The angle at which the piston 6 can tilt relative to the ball screw pair includes at least the maximum angle of tilt of the shaft coupling 2 caused by deformation of the brake caliper body 3 and the maximum angle of tilt of the parallel moving member 4b caused by wear of the brake pads.

[0076] As shown in Figures 5 and 7, the adjustment member 8 is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends in the longitudinal direction. The spherical surfaces at both ends of the adjustment member 8 contact the adjacent pair members, respectively, to form a two-spherical pair mechanism. Relative deflection can occur between the adjustment member 8 and the pair member. The intermediate portion of the adjustment member 8 is divided into at least two engaging portions with different cross-sectional sizes. All engaging portions are arranged in sequence along the longitudinal direction of the intermediate portion. Adjacent pair members respectively engage with the two engaging portions of the intermediate portion. Furthermore, adjacent pair members rotate synchronously.

[0077] The intermediate portion of the adjustment member 8 may have a torque-transmitting structure such as a polyhedron, spline, or rectangular shape. The adjustment member 8 transmits torque between the shaft coupling 2 and the rotating member 4a. The shaft coupling 2 allows the rotating member 4a to rotate through the adjustment member 8. In this embodiment, as shown in FIG. 7, the engaging portion of the intermediate portion of the adjustment member 8 is hexahedron. Two engaging portions are provided, and the sizes of the two engaging portions are different. The centers of the engaging portions and the spherical cores of both end faces of the adjustment member 8 are located on the axis of the adjustment member 8. The parallel moving member 4b is provided inside with a first groove that accommodates the spherical end face of one end of the adjustment member 8 and a first inner hole that accommodates one of the engaging portions. The first inner hole is a hexagonal hole with the same shape as the engaging portion. A small gap exists between the inner wall surface of the first inner hole and the outer wall surface of the engaging portion. The piston 6 is provided with a second groove that accommodates the spherical end surface of the other end of the adjustment member 8 and a second inner bore that accommodates the other engagement portion. A small gap exists between the inner wall surface of the second inner bore and the outer wall surface of the engagement portion. The second inner bore is a hexagonal hole with the same shape as the engagement portion. The first and second grooves are spherical grooves. The size of the engagement portion that engages with the translation member 4b is larger than the size of the engagement portion that engages with the piston 6. A wave spring 9 is attached between the adjustment member 8 and the translation member 4b. The wave spring 9 is located in the first inner bore. The wave spring 9 is sandwiched between the engagement portion that engages with the translation member 4b and the inner wall surface of the first inner bore. The wave spring 9 applies an axial elastic force to the translation member 4b, urging the translation member 4b to move axially toward a position close to the shaft coupling 2. As a result, the wave spring 9 can eliminate an axial gap between the shaft coupling 2 and the adjustment member 8 and maintain the adjustment member 8 in its restored state when no force is applied. The interior of the parallel moving member 4b has a square groove and a spherical surface. An annular groove is formed in the side wall of the parallel moving member 4b, and a retaining ring 11 is attached in the annular groove. The parallel moving member 4b is connected to the piston 6 via the retaining ring 11. The retaining ring 11 realizes relative fixation of the piston 6 and the parallel moving member 4b in the axial direction. The retaining ring 11 fixes the parallel moving member 4b and the piston 6 so that they are operatively connected.

[0078] As shown in FIG. 5 , the brake caliper of this embodiment further includes an anti-rotation mechanism. The anti-rotation mechanism is provided between the piston 6 and the brake caliper body 3. The anti-rotation mechanism includes an anti-rotation screw 7 and a groove. The anti-rotation screw 7 is provided in the brake caliper body 3. The groove is provided in the outer wall of the piston 6 and extends in the axial direction of the piston 6. The anti-rotation screw 7 is inserted into the groove to prevent the piston 6 and the translation member 4b from rotating in conjunction with the rotation member 4a. This allows the translation member 4b and the piston 6 to move linearly in the axial direction when the rotation member 4a rotates.

[0079] As shown in Figure 5, the brake caliper of this embodiment further includes a first bearing 5. The first bearing 5 is a thrust needle bearing. The rotating member 4a has one open end and the other closed end, and is hollow inside. Since the first bearing 5 and the two spherical pair mechanisms are both located in the internal cavity of the rotating member 4a, the axial size of the caliper can be reduced.

[0080] As shown in Figure 5, an elastic ring 12 and a dust cover 13 are attached between the piston 6 and the cylinder bore of the brake caliper body 3 for sealing. The elastic ring 12 and the dust cover 13 are arranged in this order along the axial direction of the cylinder bore. The inner peripheries of the elastic ring 12 and the dust cover 13 are tightly fitted to the outer wall of the piston 6. The elastic ring 12 and the dust cover 13 provide two support points for the piston 6, allowing the piston 6 to maintain a coaxial state with the cylinder bore when rotating in and out.

[0081] As shown in Figure 5, the shaft coupling 2 and the rotating member 4a are fixedly connected by means of screws, welding, etc. A retaining ring 11 is provided between the parallel moving member 4b and the piston 6 to form an operable connection. The middle portion of the adjusting member 8 has a non-circular design to prevent the piston 6 from rotating relative to the parallel moving member 4b. [Example]

[0082] As shown in Figures 6 and 8, the brake caliper structure of this embodiment differs from that of the brake caliper of the third embodiment in the following respects. Specifically, in this embodiment, the piston 6 accommodates only a portion of the ball screw pair. A portion of the parallel-movement member 4b is located within the internal cavity of the piston 6, while another portion of the parallel-movement member 4b is located outside the piston 6. The groove of the anti-rotation mechanism is provided on the outer wall of the parallel-movement member 4b. The outer wall of the parallel-movement member 4b engages with the inner wall of the cylinder bore. A radial spring 14 is provided between the piston 6 and the parallel-movement member 4b. Even if the piston 6 is subjected to a radial force and undergoes radial displacement, the normal operation of the ball screw pair is not affected by the adjustment of the two-spherical pair mechanism. Furthermore, when the brake is released, the piston 6 returns to its initial position due to the action of the restoring force of the radial spring 14.

[0083] 8, in this embodiment, the middle portion of the adjustment member 8 has a cylindrical structure, and the engagement portion is a cylindrical body. The adjustment member 8 does not have a function of transmitting torque.

[0084] In the brake calipers of Examples 3 and 4, the position of the adjustment member 8 is mainly changed, but the operating principle of the brake calipers is the same as that of the brake caliper of Example 1, so it will not be described in detail here.

[0085] The present invention has been described above by way of example in conjunction with the drawings. Needless to say, the specific implementation of the present invention is not limited to the above-mentioned manner. Various insubstantial improvements made by using the methods, concepts and technical means of the present invention, or the direct application of the above concepts and technical means of the present invention to other situations without any improvements, are all within the scope of protection of the present invention. [Explanation of symbols]

[0086] 1 actuator 2 shaft coupling 3 Brake caliper body 4. Motion conversion mechanism 4a Rotating member 4b Parallel moving member 4c Position regulation mechanism 5 First bearing 6 pistons 7 Anti-rotation screw 8 Adjustment member 9 Spring 10 Second bearing 11 Retaining ring 12 Elastic Rings 13 Dust cover 14 Radial spring 15 screws 16 Inner brake pads 17 Brake disc 18 Outer brake pads

Claims

1. A brake caliper including an actuator, a brake caliper body, and a motion conversion mechanism, The brake caliper further comprises an adjustment member disposed in the flow of axial force transmission between the actuator and the brake disc, the adjustment member being operably connected to the counter member so that the motion conversion mechanism has an adjustable degree of freedom with respect to rotation angle and / or radial displacement.

2. 2. The brake caliper according to claim 1, wherein the adjusting member forms a spherical pair, a conical pair, a planar pair, or a combination of two of these with an adjacent pair of adjusting members.

3. 2. The brake caliper according to claim 1, wherein the adjustment member is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends, and the spherical surfaces at both ends of the adjustment member are in contact with adjacent counter members to form a two-spherical counter mechanism.

4. 4. The brake caliper according to claim 3, wherein the intermediate portion of the adjustment member is divided into at least two engaging portions having different cross-sectional sizes, and the adjacent pair members engage with the two engaging portions of the intermediate portion, respectively, and the adjacent pair members rotate synchronously.

5. 5. The brake caliper according to claim 4, further comprising a shaft coupling, wherein the actuator is connected to the motion conversion mechanism via the shaft coupling.

6. 6. The brake caliper according to claim 5, wherein the motion conversion mechanism includes a parallel moving member and a rotating member, the rotating member is connected to the shaft coupling, the adjustment member is disposed between the shaft coupling and the rotating member, the adjustment member forms a spherical joint mechanism with the shaft coupling and the rotating member, and the joint member includes the shaft coupling and the rotating member.

7. 7. The brake caliper according to claim 6, wherein the engaging portion has a non-cylindrical structure, and the shaft coupling and the rotating member are connected via the adjusting member to realize synchronous rotation.

8. 8. The brake caliper according to claim 7, wherein the engaging portion has a spline or rectangular structure.

9. 7. The brake caliper according to claim 6, wherein the engaging portion has a cylindrical structure, and the shaft coupling and the rotating member are connected by a spline or a rectangular structure to realize synchronous rotation.

10. 6. The brake caliper according to claim 5, further comprising a piston, wherein the motion conversion mechanism includes a parallel moving member and a rotation member, the adjustment member is disposed between the parallel moving member and the piston, the adjustment member constitutes a spherical joint mechanism together with the piston and the parallel moving member, and the joint member includes the piston and the parallel moving member.

11. 11. The brake caliper of claim 10, wherein a fixed connection is formed between the coupling and the rotating member by threading, riveting or welding, and an operable connection is formed between the translation member and the piston by a retaining ring.

12. 12. The brake caliper of claim 11, wherein the piston has a cavity, the cavity completely houses the motion conversion mechanism, and an outer wall of the piston engages with a cylinder bore of the brake caliper body.

13. 12. The brake caliper of claim 11, wherein the piston has a cavity, the cavity completely accommodating a portion of the motion conversion mechanism, and an outer wall of the translation member engages with a cylinder bore of the brake caliper body.

14. 14. The brake caliper of claim 13, wherein a radial spring is mounted between said translation member and said piston.

15. The brake caliper according to claim 10, wherein the engaging portion has a non-cylindrical structure, and the parallel moving member and the piston are connected via the adjusting member to achieve synchronous axial movement.

16. 16. The brake caliper according to claim 15, wherein the engaging portion has a spline or rectangular structure.

17. 11. The brake caliper according to claim 10, wherein the engaging portion has a cylindrical structure.

18. 17. The brake caliper according to claim 6, wherein an anti-rotation mechanism is provided between the parallel moving member and the brake caliper body, or between the piston and the brake caliper body.

19. 17. The brake caliper according to claim 6, wherein an elastic ring and a dust cover are attached between the parallel moving member and the cylinder hole of the brake caliper body, or between the piston and the cylinder hole of the brake caliper body.

20. 17. The brake caliper according to claim 6, further comprising a bearing, wherein the bearing and the two-spherical pair mechanism are disposed inside the parallel moving member or the piston.

21. 17. The brake caliper according to claim 6, wherein a position restriction mechanism is provided between the rotation member and the translation member, the position restriction mechanism being adapted to fit each other.

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