Brake caliper and method for manufacturing the same

Abstract

To obtain, for example, a brake caliper whose appearance can be improved.SOLUTION: A brake caliper according to one embodiment includes a cylinder provided with a bore, and a claw that is located away from the cylinder in a first axial direction along a central axis and is provided with a passage. An end of the bore in the first axial direction is opened to the outside of the cylinder. The brake caliper includes a body where the passage passes through the claw along the central axis, and a cover that is disposed at least partially inside the passage and is fixed to the claw.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to brake calipers and methods of manufacturing brake calipers. [Background technology]

[0002] A conventional brake caliper includes a caliper body and a piston that presses against brake pads. The caliper body has a cylinder with a bore and a pawl spaced from the cylinder. A pair of brake pads are disposed between the cylinder and the pawl and are pressed against a rotor by the pawl and the piston fitted in the bore.

[0003] A passage such as a notch is provided in the claw for machining a bore and for accommodating the bore of an internal part such as a piston. For example, a cover that covers the claw from the outside and hides the passage is known. The cover is fastened to the claw with a screw (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5715932 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the appearance of the brake caliper can be improved by blocking the passage with a configuration other than the conventional configuration, without being limited to the conventional configuration.

[0006] Therefore, the present invention has been made in view of the above, and provides a brake caliper and a method for manufacturing a brake caliper that can improve the appearance. [Means for solving the problem]

[0007] A brake caliper according to an embodiment of the present invention includes, for example, a cylinder having a bore, a pawl spaced from the cylinder in a first axial direction along the central axis of the bore and having a passage formed therein, the end of the bore in the first axial direction being open to the outside of the cylinder, and the passage penetrating the pawl along the central axis, and a cover disposed at least partially inside the passage and fixed to the pawl. Thus, for example, the brake caliper allows internal components such as a piston and a rotary-to-linear motion conversion mechanism to be housed in the bore through the passage, improving operability. Furthermore, the brake caliper's appearance can be improved by closing the passage with a cover. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view schematically showing a braking device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the braking device of the first embodiment taken along line F2-F2 in FIG. [Figure 3] FIG. 3 is a perspective view showing the caliper body and the cover of the first embodiment. [Figure 4] FIG. 4 is a perspective view showing the caliper body and the cover of the first embodiment from a different direction than that of FIG. [Figure 5] FIG. 5 is a cross-sectional view schematically showing a part of the EPB of the first embodiment taken along line F5-F5 in FIG. [Figure 6] FIG. 6 is a perspective view schematically illustrating the cover and the claws separated from each other according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a cover and a claw to be friction stir welded according to the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view schematically showing the cover and the claws to be cut in the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view schematically showing a part of the EPB according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) The first embodiment will be described below with reference to FIGS. 1 to 8. In this specification, components according to the embodiment and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0010] In the following description, "suppress" is defined as, for example, preventing an event, action, or influence from occurring, or reducing the severity of an event, action, or influence. Also, in the following description, "restrict" is defined as, for example, preventing movement or rotation, or allowing movement or rotation within a predetermined range and preventing movement or rotation beyond the predetermined range.

[0011] FIG. 1 is a front view that schematically shows a braking device 10 according to a first embodiment. FIG. 2 is a cross-sectional view that schematically shows the braking device 10 of the first embodiment along line F2-F2 in FIG. 1. The braking device 10 is a disc brake that is mounted on a vehicle 1 such as a four-wheeled automobile. However, the braking device 10 is not limited to this example. As shown in FIG. 1, the braking device 10 has a disc rotor 11 and an electric parking brake (EPB) 12.

[0012] The disc rotor 11 rotates around a central axis Axd integrally with the wheel of the vehicle 1. The central axis Axd is, for example, the central axis of an axle, the central axis of the disc rotor 11, and also the central axis of rotation of the disc rotor 11. Note that the central axis Axd is not limited to this example.

[0013] Hereinafter, the direction along the central axis Axd will be referred to as the axial direction, the direction perpendicular to the central axis Axc as the radial direction, and the direction around the central axis Axc as the circumferential direction. The axial direction is a direction that roughly follows the width of the vehicle 1 and includes the outward direction Do and inward direction Di shown in FIG. 2. The outward direction Do is a direction that follows the central axis Axd and is an example of a first axial direction. The inward direction Di is the opposite direction to the outward direction Do and is an example of a second axial direction. For example, the outward direction Do is a direction toward the outside of the vehicle 1, and the inward direction Di is a direction toward the inside of the vehicle 1.

[0014] 1, the disc rotor 11 has a rotor body 11a and a hat portion 11b. The rotor body 11a is formed in a disk shape that is substantially perpendicular to the central axis Axd. The hat portion 11b is formed in a substantially cylindrical shape and is coupled to, for example, an axle of the vehicle 1.

[0015] The EPB 12 can operate as a hydraulic service brake and can also operate as an electric brake. As shown in Fig. 2, the EPB 12 of this embodiment has a brake caliper 21, a pair of brake pads 22, and a drive unit 23. The drive unit 23 may also be referred to as a motor gear unit (MGU).

[0016] For example, the brake caliper 21 and the brake pad 22 constitute a hydraulic service brake, and the brake caliper 21, the brake pad 22, and the drive unit 23 constitute an electric brake. The braking device 10 may omit the drive unit 23 and simply provide a hydraulic service brake. The EPB 12 is configured so that the braking state provided by the electric brake function is maintained when the vehicle is parked. The electric brake may be activated when the vehicle is traveling or when the vehicle is temporarily stopped.

[0017] The brake caliper 21 is, for example, a floating caliper. The brake caliper 21 is disposed so as to straddle the rotor body 11a. The brake caliper 21 includes a mounting 31, a caliper body 32, a piston seal 33, a cover 34, a piston 35, and a rotary-to-linear motion conversion mechanism 36. The caliper body 32 is an example of a body.

[0018] The mounting 31 is fixed to a non-rotating portion of the vehicle 1. For example, the mounting 31 is attached to the body of the vehicle 1. The mounting 31 supports the brake pads 22 and the caliper body 32 so that they are axially movable.

[0019] The caliper body 32 is made of a metal such as an aluminum alloy, and includes a cylinder 41, a pawl 42, and a bridge 43. However, the caliper body 32 is not limited to this example.

[0020] The cylinder 41 has an outer end surface 41a and an inner end surface 41b. The outer end surface 41a is provided at the end of the cylinder 41 in the outward direction Do. The inner end surface 41b is provided at the end of the cylinder 41 in the inward direction Di. The cylinder 41 is provided with a bore 45, an insertion hole 46, a seal groove 47, and a flow path 48.

[0021] The bore 45 is recessed in an inward direction Di from the outer end surface 41a along the central axis Axc. That is, the end of the bore 45 in the outward direction Do opens at the outer end surface 41a and is open to the outside of the cylinder 41. The central axis Axc is the central axis of the bore 45, extending substantially parallel to the central axis Axd of the disc rotor 11. Because the central axis Axc is substantially parallel to the central axis Axd, the outward direction Do and the inward direction Di are also directions along the central axis Axc.

[0022] The cylinder 41 further has an inner circumferential surface 45a and a bottom surface 45b that define the bore 45. The inner circumferential surface 45a is a substantially cylindrical curved surface extending along the central axis Axc. The end of the inner circumferential surface 45a in the outward direction Do is connected to the outer end surface 41a. The bottom surface 45b is located at the end of the bore 45 in the inward direction Di and is connected to the end of the inner circumferential surface 45a in the inward direction Di. The inner end surface 41b of the cylinder 41 is located opposite the bottom surface 45b.

[0023] The insertion hole 46 extends along the central axis Axc between the inner end surface 41b and the bottom surface 45b. The insertion hole 46 communicates between the bore 45 and the outside of the cylinder 41. The diameter of the insertion hole 46 is smaller than the diameter of the bore 45.

[0024] The seal groove 47 opens to the inner circumferential surface 45a. The seal groove 47 extends around the central axis Axc. The piston seal 33 is fitted in the seal groove 47. The flow passage 48 is spaced inward from the seal groove 47 in the inward direction Di and opens to the inner circumferential surface 45a. Brake fluid is supplied to or discharged from the bore 45 through the flow passage 48.

[0025] Fig. 3 is a perspective view showing the caliper body 32 and the cover 34 of the first embodiment. As shown in Fig. 2, the pawl 42 is spaced from the cylinder 41 in the outward direction Do. The pawl 42 is formed in a plate shape arranged approximately perpendicular to the axial direction. A space S is provided between the cylinder 41 and the pawl 42. The space S is open radially inward and circumferentially.

[0026] The bridge 43 connects the ends of the cylinder 41 and the claws 42 on the radially outer side. In other words, the claws 42 protrude radially inward from the bridge 43. A space S is provided on the radially inner side of the bridge 43.

[0027] Fig. 4 is a perspective view showing the caliper body 32 and cover 34 of the first embodiment from a different direction than Fig. 3. Fig. 5 is a cross-sectional view schematically showing a portion of the EPB 12 of the first embodiment along line F5-F5 in Fig. 1. As shown in Figs. 4 and 5, the claw 42 has an outer surface 42a, an inner surface 42b, and an end surface 42c. The inner surface 42b is an example of a third side surface.

[0028] As shown in FIG. 5, the outer surface 42a is provided at the end of the claw 42 in the outward direction Do. In other words, the outer surface 42a is the end face of the claw 42 in the outward direction Do. The inner surface 42b is located opposite the outer surface 42a and is provided at the end of the claw 42 in the inward direction Di. In other words, the inner surface 42b is the end face of the claw 42 in the inward direction Di. The inner surface 42b faces the cylinder 41 through the space S. As shown in FIG. 4, the end face 42c is provided at the end of the claw 42 on the radially inner side.

[0029] Fig. 6 is a perspective view schematically showing the cover 34 and the claw 42 of the first embodiment separated from each other. As shown in Fig. 6, a notch 50 is provided in the claw 42. The notch 50 is an example of a passage. Note that the passage is not limited to the notch 50 having one open end, but may be a closed hole. The notch 50 has a through-hole portion 51 and an open portion 52.

[0030] The through-hole portion 51 has a circular cross-section that is concentric (coaxial) with the bore 45, and penetrates the claw 42 along the central axis Axc. The diameter of the through-hole portion 51 is equal to or greater than the diameter of the bore 45. That is, the through-hole portion 51 can expose the entire bore 45. The cutout 50 includes an open portion 52 in addition to the through-hole portion 51. Therefore, in a projection view taken along the central axis Axc, the notch 50 is larger than the bore 45.

[0031] The open portion 52 opens to the outer surface 42 a, the inner surface 42 b, and the end surface 42 c. Therefore, the notch 50 as a whole opens to the outer surface 42 a, the inner surface 42 b, and the end surface 42 c. The width of the open portion 52 in the circumferential direction is equal to or greater than the diameter of the through-hole portion 51.

[0032] 5, the pawl 42 further has a first inner circumferential surface 50a, a second inner circumferential surface 50b, and a support surface 50c that define a notch 50. The first inner circumferential surface 50a extends inwardly from the outer surface 42a along the central axis Axc. The second inner circumferential surface 50b extends inwardly from the inner surface 42b along the central axis Axc. The portion of the notch 50 that is on the inside of the second inner circumferential surface 50b is smaller than the portion of the notch 50 that is on the inside of the first inner circumferential surface 50a.

[0033] The support surface 50c extends between an end of the first inner circumferential surface 50a in the inward direction Di and an end of the second inner circumferential surface 50b in the outward direction Do. The support surface 50c is, for example, formed to be substantially flat and faces the outward direction Do. Note that the support surface 50c is not limited to this example.

[0034] The cross section of the notch 50 perpendicular to the central axis Axc gradually decreases in the inward direction Di. However, the notch 50 is not limited to this example. For example, the cross section of the notch 50 may be constant, may continuously decrease in the inward direction Di, or may decrease in the outward direction Do.

[0035] The cover 34 is fixed to the claws 42. The material of the cover 34 is, for example, an aluminum alloy, which is the same as the material of the caliper body 32. However, the material of the cover 34 may be another material such as iron, or may be different from the material of the caliper body 32.

[0036] The cover 34 is formed in a plate shape and arranged so as to be approximately perpendicular to the central axis Axc. The cover 34 has an outer surface 34a and an inner surface 34b. The outer surface 34a is an example of a first side surface. The inner surface 34b is an example of a second side surface.

[0037] The outer surface 34a is provided at an end of the cover 34 in the outward direction Do. In other words, the outer surface 34a is the end face of the cover 34 in the outward direction Do. The inner surface 34b is located opposite the outer surface 34a and is provided at an end of the cover 34 in the inward direction Di. In other words, the inner surface 34b is the end face of the cover 34 in the inward direction Di. The inner surface 34b faces the piston 35, the cylinder 41, and the bore 45 through the space S.

[0038] The cover 34 is disposed inside the notch 50. Note that the cover 34 may be disposed partially inside the notch 50 and partially outside the notch 50. As shown in FIG. 6, the cover 34 further has an end face 34c and an outer peripheral surface 34d. The end face 34c and the outer peripheral surface 34d extend between the edge of the outer surface 34a and the edge of the inner surface 34b. The end face 34c is provided at an end of the cover 34 on the inside in the radial direction.

[0039] 5, the inner surface 34b of the cover 34 faces the support surface 50c of the claw 42 with a small gap therebetween. Therefore, the cover 34 is farther from the cylinder 41 than the inner surface 42b of the claw 42. The inner surface 34b may come into contact with the support surface 50c.

[0040] The outer peripheral surface 34d of the cover 34 faces the first inner peripheral surface 50a of the claw 42 with a small gap therebetween. The outer peripheral surface 34d may be in contact with the first inner peripheral surface 50a of the claw 42. The shape of the outer peripheral surface 34d is approximately the same as the shape of the first inner peripheral surface 50a.

[0041] The outer surface 34a of the cover 34 and the outer surface 42a of the claw 42 are substantially continuous. As shown in Fig. 4, the end surface 34c of the cover 34 and the end surface 42c of the claw 42 are substantially continuous. The cover 34 may protrude or be recessed from the outer surface 42a and the end surface 42c of the claw 42.

[0042] 5, the cover 34 of this embodiment is fixed to the claws 42 by friction stir welding (FSW). In other words, the brake caliper 21 has a joint Pf where the cover 34 and the claws 42 are friction stir welded together. Note that the cover 34 may also be fixed to the claws 42 by welding, screwing, or another method.

[0043] At the joint Pf, the cover 34 and the claw 42 are integrated. Note that the cover 34, the claw 42, and the joint Pf can be distinguished from one another based on, for example, appearance, crystal orientation, material composition, or other factors. Therefore, even if the cover 34 completely covers the notch 50, it can be determined that the notch 50 is provided in the claw 42 and that the cover 34 covers the notch 50.

[0044] In this embodiment, the joint Pf joins the entire edge (entire periphery) of the outer surface 34a connected to the outer peripheral surface 34d to the claws 42. Furthermore, the joint Pf joins a portion of the edge of the end surface 34c connected to the outer peripheral surface 34d and a portion of the outer peripheral surface 34d to the claws 42. However, the length (depth) of the joint Pf in the axial direction is shorter than the length (thickness) of the cover 34. Therefore, the other portion of the edge of the end surface 34c connected to the outer peripheral surface 34d and the other portion of the outer peripheral surface 34d are not joined to the claws 42. Furthermore, the joint Pf is spaced apart from the inner surface 34b.

[0045] The entire outer peripheral surface 34d may be joined to the claws 42. In this case, the edges of the inner surface 34b connected to the outer peripheral surface 34d are also joined to the claws 42. Furthermore, the edges of the outer surface 34a connected to the outer peripheral surface 34d may be partially joined to the claws 42. That is, the cover 34 may be fixed to the claws 42 by friction stir spot welding (FSSW), and a plurality of joints Pf may be provided.

[0046] 5, the overall cross section of the joint Pf is formed, for example, in a semicircular or trapezoidal shape tapering in the inward direction Di. In other words, the cross section of the joint Pf tapers from the outer surface 34a toward the inner surface 34b. However, the shape of the joint Pf is not limited to this example.

[0047] The brake caliper 21 further has a coating C and a logotype (logo) L. The coating C is, for example, paint. The logo L may also be referred to as printing. The coating C is provided on the outer surface 34a of the cover 34 and the outer surface 42a of the claw 42, straddling the joint Pf. The coating C may also be provided on other portions of the caliper body 32 and the cover 34. The logo L is provided on the coating C or on the outer surface 34a of the cover 34 and the outer surface 42a of the claw 42, straddling the joint Pf. The brake caliper 21 may have a picture, pattern, or other printing in addition to or instead of the logo L.

[0048] 2, the piston 35 is formed in a generally cylindrical shape that is open inwardly Di. The piston 35 has an outer peripheral surface 35a. The outer peripheral surface 35a is a generally cylindrical curved surface that extends along the central axis Axc.

[0049] The piston 35 is fitted into the bore 45 so as to be movable along the central axis Axc. In other words, the piston 35 is housed in the bore 45. A portion of the piston 35 may be located outside the bore 45. The diameter of the outer peripheral surface 35a of the piston 35 is slightly smaller than the diameter of the inner peripheral surface 45a that defines the bore 45. The outer peripheral surface 35a and the inner peripheral surface 45a face each other.

[0050] When the piston 35 is fitted into the bore 45, the piston seal 33 fitted in the seal groove 47 comes into contact with the outer circumferential surface 35a of the piston 35. As a result, the piston seal 33 seals the gap between the piston 35 and the cylinder 41 watertightly.

[0051] The piston 35 and the cylinder 41 define a pressure chamber R that is part of the bore 45. The pressure chamber R communicates with a flow path 48. The piston seal 33 provides a watertight seal between the pressure chamber R and the outside.

[0052] The rotary-linear motion conversion mechanism 36 has a rotary member 61, a linear motion member 62, and a bearing 63. The rotary member 61 may also be referred to as a bolt. The linear motion member 62 may also be referred to as a nut. The caliper body 32 accommodates at least a portion of the rotary member 61, at least a portion of the linear motion member 62, and the bearing 63 in the bore 45.

[0053] The rotation member 61 is supported by the cylinder 41 so as to be rotatable about a central axis Axc. The rotation member 61 has a flange 65, a connecting shaft 66, and a screw shaft 67.

[0054] The flange 65 is formed in a disk shape that is approximately perpendicular to the central axis Axc. The diameter of the flange 65 is smaller than the diameter of the bore 45. The flange 65 is supported on the bottom surface 45b of the cylinder 41 via a bearing 63. The bearing 63 is, for example, a thrust bearing. The flange 65 is located between the connecting shaft 66 and the screw shaft 67.

[0055] The connecting shaft 66 and the screw shaft 67 are each formed in a generally cylindrical shape extending along the central axis Axc. In this embodiment, the central axis Axc also serves as the central axis of the flange 65, the connecting shaft 66, and the screw shaft 67.

[0056] The coupling shaft 66 extends inwardly Di from the flange 65 and is fitted into the insertion hole 46. A gap between the inner peripheral surface of the insertion hole 46 and the coupling shaft 66 is sealed watertight. The threaded shaft 67 extends outwardly Do from the flange 65. The threaded shaft 67 has an outer peripheral surface 67a and a male thread 67b. The outer peripheral surface 67a is formed in a substantially cylindrical shape extending along the central axis Axc. The outer peripheral surface 67a faces the inner peripheral surface 45a of the bore 45 via a gap. The male thread 67b is provided on the outer peripheral surface 67a.

[0057] The linear motion member 62 is attached to the rotating member 61 so as to move in an outward direction Do or an inward direction Di in response to rotation of the rotating member 61. The linear motion member 62 is formed in a substantially cylindrical shape extending along the central axis Axc. The linear motion member 62 has an inner circumferential surface 62a and a female thread 62b.

[0058] The inner circumferential surface 62a is a substantially cylindrical curved surface extending along the central axis Axc and facing the central axis Axc. The female thread 62b is provided on the inner circumferential surface 62a. The screw shaft 67 of the rotating member 61 is fitted into the inside of the linear motion member 62, and the female thread 62b and the male thread 67b mesh with each other. In this way, the linear motion member 62 is attached to the screw shaft 67.

[0059] The linear motion member 62 and at least a portion of the screw shaft 67 are housed inside the piston 35. The linear motion member 62 is attached to the piston 35, for example, with its rotation around the central axis Axc restricted. Meanwhile, the linear motion member 62 can move away from the piston 35 in the inward direction Di.

[0060] The pair of brake pads 22 are located in a space S between the cylinder 41 and the pawl 42. The pair of brake pads 22 are spaced apart from each other along the central axis Axc. The rotor body 11a of the disc rotor 11 is disposed between the pair of brake pads 22.

[0061] One of the brake pads 22 contacts the piston 35. The other brake pad 22 contacts the inner surface 42b of the claw 42 and is spaced apart from the cover 34. The cover 34 may contact the brake pad 22.

[0062] The driving device 23 is attached to the cylinder 41. The driving device 23 includes, for example, a motor and a reducer. The reducer of the driving device 23 is coupled to the connecting shaft 66 of the rotating member 61. The driving device 23 is driven by driving power based on a control signal, and rotates the rotating member 61 around the central axis Axc.

[0063] Brake fluid fills the pressure chamber R. For example, a master cylinder or pump of the braking device 10 increases the pressure in the pressure chamber R through the flow path 48 in response to brake pedal operation or ECU control. The increase in pressure in the pressure chamber R moves the piston 35 outward Do, pressing one brake pad 22 against the rotor body 11a.

[0064] When one brake pad 22 is pressed against the rotor body 11a, the caliper body 32 moves inward in reaction to the force Di. This causes the claws 42 of the caliper body 32 to press the other brake pad 22 inward in the direction Di. This causes the pair of brake pads 22 to be pressed against the rotor body 11a.

[0065] The pair of brake pads 22 receive a circumferential force from the disc rotor 11 due to friction between the brake pads 22 and the rotor body 11a. The mounting 31 receives the braking force (braking torque) transmitted via the pair of brake pads 22 and transmits it to the body of the vehicle 1. In this way, the braking device 10 brakes the disc rotor 11 as a service brake.

[0066] The piston seal 33 has a retraction function that, as the pressure in the pressure chamber R decreases, retracts the piston 35 in the inward direction Di toward the pressure chamber R, separating the piston 35 from the brake pad 22. In other words, as the pressure in the pressure chamber R decreases, the piston 35 is released from pressing the brake pad 22, and the piston 35 releases the brake pad 22 from pressing against the rotor body 11a. This causes the braking device 10 to enter a brake release state in the service brake.

[0067] When the driving device 23 rotates the rotating member 61 in one direction around the central axis Axc, the linearly moving member 62 moves linearly in the outward direction Do. The piston 35 is pushed in the outward direction Do by the linearly moving member 62 moving in the outward direction Do, and presses the brake pad 22 against the rotor body 11a. As a result, the braking device 10 attains a braking state by the electric brake, in which the wheel of the vehicle 1, which rotates integrally with the disc rotor 11, is braked.

[0068] When the driving device 23 rotates the rotating member 61 in the reverse direction around the central axis Axc, the linear motion member 62 moves linearly in the inward direction Di. The piston 35 moves in the inward direction Di due to the retraction function of the piston seal 33. The pressing force of the piston 35 on the brake pad 22 decreases, and the piston 35 releases the brake pad 22 from pressing against the rotor body 11a. This causes the braking device 10 to enter a released state (non-braking state) in which braking by the electric brake is released.

[0069] The EPB 12 is manufactured, for example, as follows. Note that the manufacturing method of the EPB 12 is not limited to the following method, and other methods may also be used. First, the caliper body 32 is manufactured by casting. Next, a drill is inserted through the notch 50 into a recess formed in the cylinder 41 by casting, thereby forming the bore 45. Note that various other tools, such as a milling cutter, may be used to form the bore 45.

[0070] Next, the piston 35 and the rotary-to-linear motion conversion mechanism 36 are accommodated in the bore 45 through the notch 50. The piston 35 and the rotary-to-linear motion conversion mechanism 36 are an example of built-in components. In the axial direction, the rotating member 61 is longer than the distance between the cylinder 41 and the pawl 42. Therefore, the rotary-to-linear motion conversion mechanism 36 can be easily accommodated in the bore 45 by passing through the notch 50. The piston 35 does not have to pass through the notch 50.

[0071] 6, after the piston 35 and the rotary-to-linear motion conversion mechanism 36 are housed in the bore 45, the cover 34 is placed inside the notch 50. For example, the cover 34 is supported by the support surface 50c of the claw 42. The first inner circumferential surface 50a of the claw 42 and the support surface 50c can position the cover 34.

[0072] Fig. 7 is a cross-sectional view that schematically shows the cover 34 and the claws 42 to be friction stir welded in the first embodiment. As shown in Fig. 7, the caliper body 32 is attached to a jig J. The jig J supports, for example, the inner surface 34b of the cover 34 and the inner surface 42b of the claws 42. The cover 34 supported by the jig J may be supported by the support surface 50c of the claws 42, or may be spaced apart from the support surface 50c.

[0073] Next, a rotating friction stir welding tool T is pressed against the outer surfaces 34a, 42a of the cover 34 and the claws 42. The tool T softens the cover 34 and the claws 42, causing plastic flow of the cover 34 and the claws 42. As a result, a weld Pf is formed in which the cover 34 and the claws 42 are stirred, and the cover 34 is fixed to the claws 42. The jig J receives a load from the tool T via the cover 34 and the claws 42.

[0074] The tool T may be pressed against the end faces 34c, 42c of the cover 34 and the claws 42. Furthermore, when the length (thickness) of the cover 34 and the length (thickness) of the claws 42 in the axial direction are substantially the same and the inner surfaces 34b, 42b of the cover 34 and the claws 42 are disposed on approximately the same plane, the tool T may be pressed against the inner surfaces 34b, 42b. In these cases, the caliper body 32 and the cover 34 are supported by a jig in a different orientation from that shown in FIG. 7. The tool T may be pressed against the cover 34 and the claws 42 in a direction oblique to the axial direction.

[0075] Fig. 8 is a cross-sectional view that schematically shows the cover 34 and the claws 42 being cut in the first embodiment. As shown in Fig. 8, for example, a milling cutter F or an end mill cuts the cover 34, the claws 42, and the joint Pf. This removes burrs that occur during friction stir welding, and the outer surface 34a of the cover 34 and the outer surface 42a of the claws 42 become substantially continuous. Note that the milling cutter F or the end mill does not necessarily have to cut at least one of the cover 34 and the claws 42.

[0076] 5, a coating C is applied to the outer surface 34a of the cover 34 and the outer surfaces 42a of the claws 42. Furthermore, a logo L is printed on the coating C. Removal of burrs makes it easier to apply the coating C and print the logo L.

[0077] Next, the drive unit 23 and the mounting 31 are attached to the caliper body 32. Furthermore, the brake pads 22 are attached to the mounting 31. With the above steps, the manufacturing of the EPB 12 is completed.

[0078] In the braking device 10 according to the first embodiment described above, the pawl 42 is provided with the notch 50. The cover 34 is at least partially disposed inside the notch 50 and fixed to the pawl 42.

[0079] Internal components such as the piston 35 and the rotary-to-linear motion conversion mechanism 36 are accommodated in the bore 45 of the cylinder 41 through the notch 50. After the internal components are accommodated in the bore 45, the cover 34 is placed inside the notch 50 and fixed to the claws 42.

[0080] As described above, the brake caliper 21 allows built-in components such as the piston 35 and rotary-to-linear motion conversion mechanism 36 to be easily accommodated in the bore 45 through the cutout 50, improving workability. Furthermore, by closing the cutout 50 with the cover 34, the brake caliper 21 conceals, for example, the brake pad 22. Furthermore, the cover 34 can form continuous outer surfaces 34a, 42a of the cover 34 and the pawls 42. Therefore, the brake caliper 21 can have an improved appearance. By disposing the cover 34 inside the cutout 50, the brake caliper 21 can be prevented from becoming larger.

[0081] The cover 34 and the pawls 42 are friction stir welded at the joint Pf. Because the cover 34 and the pawls 42 are integrated, the brake caliper 21 can prevent the cover 34 from coming off the caliper body 32, improve the strength of the pawls 42, and reduce the number of parts, compared to when the cover 34 is screwed to the caliper body 32. Furthermore, the brake caliper 21 can improve the degree of freedom in the shape of the contact surfaces (inner surfaces 34b, 42b) of the cover 34 and the pawls 42 that come into contact with the brake pad 22. Furthermore, the brake caliper 21 can easily adjust the natural frequencies of the cover 34 and the pawls 42, thereby reducing vibration and noise. Because the cover 34 is fixed to the caliper body 32 by friction stir welding, the brake caliper 21 can prevent distortion of the cover 34 and the pawls 42, compared to when the cover 34 is fixed to the caliper body 32 by welding.

[0082] The cross section of the welded portion Pf tapers from the outer surface 34a toward the inner surface 34b of the cover 34. The friction stir welding tool T is pressed against the outer surface 34a, thereby forming the cross section of the welded portion Pf that tapers from the outer surface 34a toward the inner surface 34b. In other words, the friction stir welding tool T is not pressed against the inner surface 34b or the end face 34c, but forms the welded portion Pf by friction stir welding from one direction. Therefore, the brake caliper 21 can be made easier to work with than when the welded portion Pf is formed by friction stir welding from multiple directions.

[0083] The cover 34 is located farther from the cylinder 41 than the inner surface 42b of the claw 42. Therefore, the brake pad 22 contacts the inner surface 42b of the claw 42, but is located farther from the cover 34. Therefore, the cover 34 can be prevented from receiving a load from the brake pad 22, and furthermore, can be prevented from coming off the claw 42 due to the load.

[0084] (Second embodiment) The second embodiment will be described below with reference to Fig. 9. In the following description of the embodiment, components having the same functions as components already described are given the same reference numerals as the components already described, and further description may be omitted. Furthermore, multiple components given the same reference numerals do not necessarily have all the same functions and properties, and may have different functions and properties according to each embodiment.

[0085] 9 is a cross-sectional view that schematically shows a portion of an EPB 12 according to a second embodiment. As shown in FIG. 9, the brake caliper 21 of the second embodiment has a cover 200 instead of the cover 34. The cover 200 is substantially identical to the cover 34, except for the points described below. Instead of the outer surface 34a, the inner surface 34b, and the outer peripheral surface 34d, the cover 200 has an outer surface 200a, an inner surface 200b, a first outer peripheral surface 200d, a second outer peripheral surface 200e, and an intermediate surface 200f.

[0086] The outer surface 200a is provided at an end of the cover 34 in the outward direction Do. The outer surface 200a is generally continuous with the outer surface 42a of the claw 42. The inner surface 200b is located opposite the outer surface 200a and is provided at an end of the cover 200 in the inward direction Di. In other words, the inner surface 200b is an end face of the cover 200 in the inward direction Di.

[0087] The inner surface 200b faces the piston 35, the cylinder 41, and the bore 45 through the space S. The inner surface 200b is closer to the cylinder 41 than the inner surface 42b of the claw 42. That is, a portion of the cover 200 protrudes from the inner surface 42b of the claw 42 toward the cylinder 41. Therefore, in the second embodiment, the inner surface 200b of the cover 200 contacts the brake pad 22. On the other hand, the inner surface 42b of the claw 42 is spaced from the brake pad 22. Note that both the inner surfaces 42b and 200b may contact the brake pad 22.

[0088] The inner surface 200b includes, for example, a circular region that is approximately concentric (coaxial) with the bore 45. Therefore, the piston 35 and the inner surface 200b of the cover 200 can press the brake pad 22 on the central axis Axc. In other words, the piston 35 and the inner surface 200b of the cover 200 can press the brake pad 22 at approximately the same position in the radial direction and the circumferential direction.

[0089] The first outer peripheral surface 200d extends inwardly from the edge of the outer surface 200a along the central axis Axc in a direction Di. The second outer peripheral surface 200e extends inwardly from the edge of the inner surface 200b along the central axis Axc in a direction Do.

[0090] The intermediate surface 200f extends between an end of the first outer peripheral surface 200d in the inward direction Di and an end of the second outer peripheral surface 200e in the outward direction Do. The intermediate surface 200f is, for example, formed to be substantially flat and faces the inward direction Di. However, the intermediate surface 200f is not limited to this example.

[0091] The first outer peripheral surface 200d of the cover 200 and the first inner peripheral surface 50a of the claw 42 face each other with a small gap between them. The second outer peripheral surface 200e of the cover 200 and the second inner peripheral surface 50b of the claw 42 face each other with a small gap between them. The intermediate surface 200f of the cover 200 and the support surface 50c of the claw 42 face each other with a small gap between them. Note that the first outer peripheral surface 200d and the first inner peripheral surface 50a, the second outer peripheral surface 200e and the second inner peripheral surface 50b, and the intermediate surface 200f and the support surface 50c may be in contact with each other.

[0092] In this embodiment, the joint Pf joins the entire edge (entire periphery) of the outer surface 200a connected to the first outer peripheral surface 200d to the claw 42. Furthermore, the joint Pf joins a portion of the edge of the end surface 34c connected to the first outer peripheral surface 200d and a portion of the first outer peripheral surface 200d to the claw 42. However, the length (depth) of the joint Pf in the axial direction is shorter than the length of the first outer peripheral surface 200d. Therefore, the other portion of the edge of the end surface 34c connected to the first outer peripheral surface 200d, the other portion of the first outer peripheral surface 200d, the second outer peripheral surface 200e, and the intermediate surface 200f are not joined to the claw 42. Furthermore, the joint Pf is spaced from the inner surface 200b. Note that the joint Pf may be provided from the outer surface 200a to the inner surface 200b.

[0093] In the EPB 12 of the second embodiment described above, the inner surface 200b is closer to the cylinder 41 than the inner surfaces 42b of the pawls 42. Therefore, the piston 35 and the inner surface 200b of the cover 200 can press the brake pads 22 at approximately the same positions in the radial and circumferential directions. Therefore, the brake caliper 21 can efficiently press the brake pads 22 against the disc rotor 11.

[0094] At least one embodiment of the brake caliper described above includes, for example, a cylinder having a bore, a pawl spaced from the cylinder in a first axial direction along the central axis of the bore and having a passage formed therein, the end of the bore in the first axial direction being open to the outside of the cylinder, and the passage penetrating the pawl along the central axis, and a cover disposed at least partially inside the passage and fixed to the pawl. Thus, for example, the brake caliper allows internal components such as a piston and a rotary-to-linear motion conversion mechanism to be housed in the bore through the passage, improving workability. Furthermore, by closing the passage with the cover, the brake caliper can conceal, for example, brake pads. Furthermore, the cover can form a continuous outer surface for the cover and the pawl. Therefore, the brake caliper's appearance can be improved. By disposing the cover inside the passage, the brake caliper can be prevented from becoming large.

[0095] As an example, the above-mentioned brake caliper further includes a joint formed by friction stir welding the cover and the pawl. Therefore, as an example, because the cover and the pawl are integrated, the brake caliper can prevent the cover from coming off the body compared to when the cover is screwed to the body, improve the strength of the pawl, and reduce the number of parts. The brake caliper also allows for greater freedom in the shape of the contact surfaces of the cover and the pawl with the brake pad. Furthermore, the brake caliper allows for easy adjustment of the natural frequencies of the cover and the pawl, thereby reducing vibration and noise. Because the cover is fixed to the body by friction stir welding, the brake caliper can prevent distortion of the cover and the pawl compared to when the cover is fixed to the body by welding.

[0096] In the above-described brake caliper, as one example, the cover has a first side surface provided at an end of the cover in the first axial direction and a second side surface located opposite the first side surface, and the cross section of the weld tapers from the first side surface toward the second side surface. Thus, as one example, a friction stir welding tool is pressed against the first side surface to form a cross section of the weld tapering from the first side surface toward the second side surface. That is, the friction stir welding tool is not pressed against the second side surface or any other side surface, and the weld is formed by friction stir welding from one direction. Therefore, the brake caliper can be made more easily than when the weld is formed by friction stir welding from multiple directions.

[0097] In the above-described brake caliper, for example, the pawl has a third side surface provided at an end of the pawl in a second axial direction opposite the first axial direction and facing the cylinder, and the cover is spaced apart from the cylinder with respect to the third side surface. Therefore, for example, the brake pad positioned between the cylinder and the pawl contacts the third side surface of the pawl but is spaced apart from the cover. Therefore, the cover can be prevented from receiving a load from the brake pad, and thus can be prevented from coming off the pawl due to the load.

[0098] The manufacturing method of the brake caliper according to at least one embodiment described above includes, for example, accommodating an internal component in a bore of a cylinder through a passage penetrating a claw spaced from the cylinder in a first axial direction along the central axis of the bore, and after the internal component is accommodated in the bore, positioning at least a portion of a cover inside the passage and fixing the cover to the claw. Therefore, for example, the manufacturing method allows the internal component to be easily accommodated in the bore, improving workability. Furthermore, the cover closes the passage, improving the appearance of the brake caliper.

[0099] While the embodiments of the present invention have been described above, the above-described embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above-described embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the configurations and shapes of each embodiment and each modification can be partially interchanged. [Explanation of symbols]

[0100] 21...Brake caliper, 32...Caliper body (body), 34,200...Cover, 34a...Outer surface (first side), 34b...Inner surface (second side), 35...Piston (internal part), 36...Rotary-linear conversion mechanism (internal part), 41...Cylinder, 42...Pawl, 42b...Inner surface (third side), 45...Bore, 50...Notch (passage), Axc...Central axis, Do...Outer direction (first axial direction), Di...Inner direction (second axial direction), Pf...Joint.

Claims

1. a body including a cylinder having a bore, and a pawl spaced from the cylinder in a first axial direction along a central axis of the bore and having a passage formed therein, wherein an end of the bore in the first axial direction is open to the outside of the cylinder, and the passage passes through the pawl along the central axis; a cover disposed at least partially within the passage and secured to the pawl; A brake caliper comprising:

2. a joint formed by friction stir welding the cover and the claw; 10. The brake caliper of claim 1, further comprising:

3. the cover has a first side surface provided at an end of the cover in the first axial direction and a second side surface located opposite the first side surface, a cross section of the joint portion tapering from the first side surface to the second side surface; The brake caliper of claim 2.

4. the claw has a third side surface provided at an end of the claw in a second axial direction opposite the first axial direction and facing the cylinder; The cover is spaced further from the cylinder than the third side surface. The brake caliper of claim 1.

5. receiving an internal component in a bore of a cylinder through a passageway passing through a pawl spaced from the cylinder in a first axial direction along a central axis of the bore; After the built-in component is accommodated in the bore, disposing at least a portion of a cover inside the passage; fastening the cover to the nail; A method for manufacturing a brake caliper comprising:

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