Caliper brake

Abstract

The present invention discloses a caliper brake, comprising: a support, on which a pair of pads are mounted for advancing and retreating; a brake caliper housing, which is slidably mounted on the support and is provided with a cylinder; a piston, which is mounted in the cylinder and is configured to advance and retreat toward the pads through brake fluid pressure; a sealing groove, which is formed as an annular recess in the inner surface of the cylinder; and an annular sealing member, which is in close contact with the outer surface of the piston and is accommodated in the sealing groove, wherein the sealing groove includes a bottom surface in close contact with the outer peripheral surface of the sealing member, a first surface facing the front surface of the sealing member, a second surface facing the rear surface of the sealing member, and a curved surface which is in contact with the bottom surface and the second surface and is configured to be arc-shaped.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2020-0090465 filed in the Korean Intellectual Property Office on July 21, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to a caliper brake, and more particularly, to a caliper brake including a sealing member that rolls back a piston when the brake is released. Background Art

[0004] Generally, a caliper brake includes a support on which a pair of pads are mounted for moving forward and backward to squeeze a disc that rotates with the wheel of the vehicle; and a caliper housing provided with a cylinder that is slidably mounted on the support and in which a piston is mounted for moving forward and backward by brake hydraulic pressure, etc.

[0005] The caliper brake performs braking by squeezing a piston with brake hydraulic pressure, and may also include an electric actuator and perform parking braking as a spindle unit, which receives rotational force from the motor of the actuator and converts the rotational motion into linear motion, pressing the piston. In this case, in order to reduce the drag phenomenon that continues to occur due to the friction between the disc and the friction pad attached to a pair of backing plates after braking, the caliper brake may use a sealing member accommodated in a sealing groove formed on the cylinder and a rollback chamber in the sealing groove to make the piston retreat.

[0006] The sealing member is formed in an annular shape to be inserted into an annular sealing groove formed on the inner surface of the cylinder of the brake caliper housing, and is disposed between the inner surface of the cylinder and the outer surface of the piston. The sealing member performs the function of preventing the leakage of the brake fluid by sealing between the inner surface of the cylinder and the outer surface of the piston, and performs the function of returning the piston to its original position. The function of the sealing member to return the advancing piston to its original position by the elastic force of the sealing member after the braking is completed is called rollback.

[0007] However, when the sealing function of the sealing member and the sealing groove that prevents brake fluid leakage is improved, the rollback function that returns the piston to its original position will deteriorate and drag will occur. Conversely, when the rollback function of the sealing member and the sealing groove is improved, the sealing function may deteriorate and cause brake fluid leakage.

[0008] An example of a conventional caliper brake including a sealing member has been disclosed in Korean Patent Publication No. 10-2015-0069695. Summary of the invention

[0009] An aspect of the present disclosure is to provide a caliper brake capable of fully realizing a rollback function of a sealing member when braking is released to prevent a drag phenomenon and improve fuel efficiency of a vehicle.

[0010] An aspect of the present disclosure is to provide a caliper brake which can fully implement a sealing function of a sealing member to prevent leakage of brake fluid even during high-pressure braking.

[0011] Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure.

[0012] According to one aspect of the present disclosure, a caliper brake includes: a support on which a pair of backing plates are mounted for advancement and retraction; a brake caliper housing slidably mounted on the support and provided with a cylinder; a piston mounted in the cylinder and configured to advance and retract toward the backing plate by brake fluid pressure; a sealing groove formed as an annular recess in the inner surface of the cylinder; and an annular sealing member in close contact with the outer surface of the piston and accommodated in the sealing groove, wherein the sealing groove includes a bottom surface in close contact with the outer peripheral surface of the sealing member, a first surface facing the front surface of the sealing member, a second surface facing the rear surface of the sealing member, and a curved surface in contact with the bottom surface and the second surface and configured to be arc-shaped.

[0013] The bottom surface may be disposed in parallel with the advancing and retreating direction of the piston.

[0014] The first surface may have a first inclined surface formed to be inclined toward the backing plate, and the second surface may have a second inclined surface formed to be inclined toward an opposite side of the backing plate.

[0015] The first inclined surface may be formed to have a depth of about 45% to 55% of a depth of the bottom surface.

[0016] The second inclined surface may be formed to have a depth of about 25% to 35% of a depth of the bottom surface.

[0017] The radius of curvature of the curved surface may be 0.7 mm to 2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] These and / or other aspects of the present disclosure will become apparent and more easily understood through the following description of embodiments in conjunction with the accompanying drawings:

[0019] Figure 1 is a schematic cross-sectional view of a caliper brake according to an embodiment of the present disclosure;

[0020] Figure 2 yes Figure 1 An enlarged cross-sectional view of section A;

[0021] Figure 3 is an enlarged cross-sectional view of a sealing member and a sealing groove of a caliper brake according to an embodiment of the present disclosure;

[0022] Figure 4 is an enlarged cross-sectional view of a sealing groove of a caliper brake according to an embodiment of the present disclosure;

[0023] Figure 5 is a cross-sectional view showing the operation of the sealing member when the piston of the caliper brake according to the embodiment of the present disclosure advances; and

[0024] Figure 6 is a cross-sectional view illustrating the operation of the sealing member when the piston of the caliper brake according to the embodiment of the present disclosure retreats. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the ideas of the present disclosure. The present disclosure is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly illustrate the present disclosure, parts not related to the description are omitted in the accompanying drawings, and for convenience, the width, length, thickness, etc. of the components may be exaggerated.

[0026] Figure 1 is a schematic cross-sectional view of a caliper brake according to an embodiment of the present disclosure.

[0027] Reference Figure 1 The caliper brake 100 according to the embodiment of the present disclosure includes: a disc D, which rotates with a wheel (not shown) of a vehicle; a support (not shown) on which a pair of backing plates 151 and 152 are mounted for advancing and retreating to press the disc D; a brake caliper housing 140, which is slidably mounted on the support (not shown) and is provided with a cylinder 141; a piston 130, which is mounted in the cylinder 141 and is configured to advance and retreat toward the backing plate 152 by brake hydraulic pressure; and an annular sealing member 110, which is in close contact with the outer surface of the piston 130 and the inner surface of the cylinder 141.

[0028] like Figure 1 As shown, the caliper brake 100 according to the embodiment of the present disclosure may be configured to implement only hydraulic braking, and although not shown in the drawings, may be configured to implement both hydraulic braking and electromechanical braking using a spindle nut or the like.

[0029] In the following description, the direction in which the piston 130 advances toward the backing plate 152 (the left side in the figure) is referred to as a forward direction, and the direction in which the piston 130 retreats from the backing plate 152 (the right side in the figure) is referred to as a backward direction.

[0030] Figure 2 yes Figure 1 A magnified cross-sectional view of section A. Figure 3 is an enlarged cross-sectional view of a sealing member and a sealing groove of a caliper brake according to an embodiment of the present disclosure, and Figure 4 is an enlarged cross-sectional view of a seal groove of a caliper brake according to an embodiment of the present disclosure.

[0031] Reference Figures 2 to 4 The sealing member 110 formed in an annular shape may be accommodated in the sealing groove 120 so that its inner peripheral surface 114 contacts the outer peripheral surface 131 of the piston 130, and the outer peripheral surface 113 of the sealing member 110 contacts the inner surface of the sealing groove 120. The cross section of the sealing member 110 may preferably be set to a rectangular shape.

[0032] The thickness of the sealing member 110, that is, the thickness of the sealing member 110 between the inner circumferential surface 114 and the outer circumferential surface 113, may be greater than the depth h1 of the sealing groove 120. Therefore, the sealing member 110 may seal between the outer circumferential surface 131 of the piston 130 and the bottom surface 123 of the sealing groove 120 while having elastic restoring force.

[0033] The sealing member 110 has a front surface 111 located in the advancing direction of the piston 130 and a rear surface 112 located in the retreating direction of the piston 130 , and the front surface 111 and the rear surface 112 may be disposed in parallel.

[0034] The sealing groove 120 is formed to be recessed in an annular shape on the inner surface of the cylinder 141 provided in the caliper housing 140 in a hollow shape, and accommodates the sealing member 110 .

[0035] Specifically, the sealing groove 120 includes a bottom surface 123 on which the outer circumferential surface 113 of the sealing member 110 is located, a first surface 121 facing the front surface 111 of the sealing member 110 , and a second surface 122 facing the rear surface 112 of the sealing member 110 .

[0036] The bottom surface 123 seals between the sealing member 110 and the cylinder 141 by friction with the outer peripheral surface 113 of the sealing member 110 .

[0037] The bottom surface 123 is formed to be parallel to the central axis or the advancing and retreating directions of the piston 130. Specifically, the bottom surface 123 is formed so that the angle of the surface on which the outer peripheral surface 113 of the sealing member 110 is located is parallel to the central axis of the piston 130 or the inner peripheral surface 141a of the cylinder 141. In other words, the depth d1 of the bottom surface 123 or the distance between the bottom surface 123 and the outer peripheral surface 131 of the piston 130 is formed to be constant.

[0038] Therefore, even when the sealing member 110 elastically deforms forward when the piston 130 advances, since the depth d1 of the bottom surface 123 is constant, the sealing performance of the sealing member 110 can be maintained compared to the case where the depth decreases forward. The detailed operation thereof will be described later.

[0039] Furthermore, even when the sealing member 110 elastically deforms backward when the piston 130 retreats, since the depth d1 of the bottom surface 123 is constant, less resistance can be generated and dragging can be reduced compared to a case where the depth decreases backward.

[0040] The front side of the bottom surface 123 is connected to the first surface 121 , and the rear side of the bottom surface 123 is in contact with the curved surface 124 and connected to the second surface 122 through the curved surface 124 .

[0041] The curved surface 124 is formed in an arc shape so that one side contacts the bottom surface 123 and the other side contacts the second surface 122. The curvature radius of the curved surface 124 may be 0.7 to 2 mm, preferably 1 mm. Therefore, the depth d2 of the curved surface 124 is formed to be smaller toward the rear.

[0042] When brake fluid pressure is applied, brake fluid is introduced from the rear of the sealing member 110 , and in this case, the sealing function of the rear of the sealing member 110 is improved by the curved surface 124 provided at the rear of the bottom surface 123 , thereby preventing brake fluid leakage.

[0043] In addition, due to the provision of the above-mentioned curved surface 124, the excessive rolling back phenomenon that occurs when the sealing member 110 is elastically deformed backward can be prevented. Specifically, when the sealing member 110 rolls back, the sealing member 110 can be elastically deformed backward or can slide backward, so that the sealing member 110 can move backward. At this time, as the depth d2 of the curved surface 124 decreases toward the rear, the sealing member 110 is elastically deformed while being subjected to the tightening force in the forward and radial directions, and the elastic deformation force of the sealing member 110 can prevent the sealing member 110 from being excessively rolled back.

[0044] The first surface 121 may be formed to be curved in a direction from the bottom surface 123 toward the piston 130 to face the front surface 111 of the sealing member 110. Preferably, the first surface 121 may be disposed perpendicular to the bottom surface 123. In this case, an edge connecting the first surface 121 and the bottom surface 123 may be formed to be rounded, and a radius of curvature of the edge is set to be smaller than a radius of curvature of the curved surface 124.

[0045] When the piston 130 advances, the first surface 121 may be in close contact with the front surface 111 due to elastic deformation of the sealing member 110 , thereby restricting movement of the sealing member 110 .

[0046] The second surface 122 may be formed to be bent in a direction from the bottom surface 123 toward the piston 130 to face the rear surface 112 of the sealing member 110 .

[0047] In the case where the sealing member 110 excessively rolls back due to the elastic reaction force when the piston 130 retreats, the second surface 122 may be in close contact with the rear surface 112 to restrict the movement of the sealing member 110 .

[0048] The first surface 121 may have a first inclined surface 121 a formed to be inclined in the advancing direction of the piston 130 , and the second surface 122 may have a second inclined surface 122 a formed to be inclined in the retreating direction of the piston 130 .

[0049] The first inclined surface 121a may be formed from the first surface 121 to a depth h1 of approximately 45% to 55% relative to the depth d1 of the bottom surface 123. However, the shape of the first inclined surface 121a is not limited thereto and may have various variations. That is, the depth and angle of the first inclined surface 121a may be changed according to the required rollback amount and should be understood in the same manner.

[0050] The second inclined surface 122a may be formed from the second surface 122 to a depth h2 of approximately 25% to 35% relative to the depth d1 of the bottom surface 123. However, the shape of the second inclined surface 122a is not limited thereto and may have various variations. That is, the depth and angle of the second inclined surface 122a may be changed according to the required amount of brake fluid, etc., and should be understood in the same manner.

[0051] Therefore, the volume of the space formed by the first inclined surface 121 a may be greater than the volume of the space formed by the second inclined surface 122 a .

[0052] The space formed by the first inclined surface 121a is a space formed between the first inclined surface 121a and the outer peripheral surface 131 of the piston 130, and can be filled by the sealing member 110 through the elastic deformation of the sealing member 110 when the piston 130 advances. The space formed by the first inclined surface 121a can provide an additional space, and the sealing member 110 can be elastically deformed forward even when the piston 130 is pressed forward, so that the occurrence of sliding between the inner peripheral surface 114 of the sealing member 110 and the outer peripheral surface 131 of the piston 130 can be reduced.

[0053] The space formed by the second inclined surface 122a is a space formed between the second inclined surface 122a and the outer peripheral surface 131 of the piston 130, and can be filled by the sealing member 110 through the elastic deformation of the sealing member 110 when the piston 130 retreats. The space formed by the second inclined surface 122a can provide an additional space, and the sealing member 110 can be elastically deformed backward even when the piston 130 retreats, thereby preventing the occurrence of sliding between the inner peripheral surface 114 of the sealing member 110 and the outer peripheral surface 131 of the piston 130.

[0054] Hereinafter, the operation of the sealing member 110 when the piston 130 of the caliper brake 100 according to the embodiment of the present disclosure advances will be described.

[0055] Figure 5 is a cross-sectional view illustrating the operation of the sealing member when the piston of the caliper brake according to the embodiment of the present disclosure advances.

[0056] Reference Figure 1 and Figure 5 When the brake hydraulic pressure changes from low pressure to high pressure, the piston 130 advances from a stationary state, and thus the sealing member 110 is elastically deformed. However, in addition to the brake hydraulic pressure, the piston 130 may also be advanced by a pressing operation of an actuator (not shown) such as a spindle nut (not shown), and it should be understood that the operation of the sealing member 110 caused by the pressing operation and the release operation of the actuator is the same as the operation of the sealing member 110 caused by the operation of the brake hydraulic pressure.

[0057] During a braking operation, the sealing member 110 is elastically deformed forward in a state where the outer circumferential surface 113 and the inner circumferential surface 114 are in close contact with the bottom surface 123 of the sealing groove 120 and the outer circumferential surface 131 of the piston 130 , respectively.

[0058] As the brake hydraulic pressure increases, the front surface 111 of the sealing member 110 closely contacts the first surface 121 of the sealing groove 120 , and a portion of the sealing member 110 closely contacts the first inclined surface 121 a to fill the front space of the sealing member 110 .

[0059] Since the depth d1 of the bottom surface 123 is set to be constant, even if the sealing member 110 is elastically deformed, the sealing state between the piston 130 and the sealing member 110 may be maintained.

[0060] For example, in the case where the depth d1 of the bottom surface 123 is formed to decrease toward the front, when the sealing member 110 is elastically deformed forward by the brake hydraulic pressure, the rear portion of the sealing member 110 has a weaker tightening force than the front portion of the sealing member 110. In this case, since the high-pressure brake hydraulic pressure is applied to the rear portion of the sealing member 110, the brake fluid may leak between the inner peripheral surface 114 of the sealing member 110 and the outer peripheral surface 131 of the piston 130.

[0061] However, in the caliper brake 100 according to the embodiment of the present disclosure, since the depth d1 of the bottom surface 123 is set to be constant, even if the sealing member 100 is elastically deformed forward, the tightening force acting on the sealing member 100 in the radial direction does not change, so that the sealing state between the piston 130 and the sealing member 110 can be maintained.

[0062] Hereinafter, the operation of the sealing member 110 during the brake releasing operation of the caliper brake 100 according to the embodiment of the present disclosure will be described.

[0063] Figure 6 is a cross-sectional view illustrating the operation of the sealing member when the piston of the caliper brake according to the embodiment of the present disclosure retreats.

[0064] Reference Figure 1 and Figure 6 When the brake hydraulic pressure is released in a state where the piston 130 is pressed forward, the piston 130 retreats by the elastic deformation force of the sealing member 110 and the elastic member (not shown), so the sealing member 110 is elastically deformed. However, the operation of retreating the piston 130 is not limited thereto, and it should be understood that retreating the piston 130 by other methods is the same as retreating the piston 130 by the elastic deformation force.

[0065] When the piston 130 retreats, the sealing member 110 elastically deforms rearward in a state where the outer circumferential surface 113 and the inner circumferential surface 114 are in close contact with the bottom surface 123 of the sealing groove 120 and the outer circumferential surface 131 of the piston 130 , respectively.

[0066] As the brake hydraulic pressure is released, the rear surface 112 of the sealing member 110 may be in close contact with the second surface 122 of the sealing groove 120 , and a portion of the sealing member 110 may be in close contact with the second inclined surface 122 a .

[0067] When the sealing member 110 elastically deforms backward while passing the curved surface 124 formed in an arc shape, the elastic deformation force acting forward on the sealing member 110 increases. This elastic deformation force presses the sealing member 110 forward to prevent excessive rolling back and improves the sealing function of the sealing member 110 to prevent brake fluid leakage.

[0068] In the caliper brake 100 according to the embodiment of the present disclosure as described above, since the depth d1 of the bottom surface 123 is set constant, the sealing member 100 can be smoothly elastically deformed to reduce the drag phenomenon. In addition, in the caliper brake 100 according to the embodiment of the present disclosure, since the curved surface 124 having the depth d2 that decreases toward the rear is provided, the tightening force applied to the rear of the sealing member 110 can be increased, so that the leakage of the brake fluid can be prevented and the excessive rolling back can be prevented.

[0069] It is apparent from the above that the caliper brake according to the embodiment of the present disclosure can fully realize the rollback function of the sealing member when the brake is released to prevent the drag phenomenon and improve the fuel efficiency of the vehicle.

[0070] Furthermore, the caliper brake according to the embodiment of the present disclosure can fully realize the sealing function of the sealing member even during high-pressure braking to prevent leakage of the brake fluid.

[0071] While the present disclosure has been described in detail with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure.

Claims

1. A caliper brake, comprising: a support on which a pair of pads are mounted for advancing and retreating; a brake caliper housing slidably mounted on the support and provided with a cylinder; a piston installed in the cylinder and configured to move forward and backward toward the backing plate by brake hydraulic pressure; a sealing groove formed as an annular recess in the inner surface of the cylinder; as well as an annular sealing member, in close contact with the outer surface of the piston and accommodated in the sealing groove, Wherein, the sealing groove comprises: a bottom surface, with which the outer peripheral surface of the sealing member is in close contact; a first surface, facing the front surface of the sealing member; a second surface, facing the rear surface of the sealing member; and a curved surface, in contact with the bottom surface and the second surface and arranged in an arc shape, wherein the first surface is arranged perpendicular to the bottom surface, The curvature radius of the curved surface is 0.7 mm to 2 mm, The depth of the bottom surface is constant, The depth of the curved surface is formed to decrease toward the rear, The first surface has a first inclined surface formed to be inclined toward the backing plate, and the second surface has a second inclined surface formed to be inclined toward an opposite side of the backing plate, and A depth of the first inclined surface is greater than a depth of the second inclined surface.

2. The caliper brake according to claim 1, wherein: The bottom surface is disposed parallel to the advancing and retreating directions of the piston.

3. The caliper brake according to claim 1, wherein: The first inclined surface is formed to have a depth of 45% to 55% of a depth of the bottom surface.

4. The caliper brake according to claim 3, wherein: The second inclined surface is formed to have a depth of 25% to 35% of a depth of the bottom surface.

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