Caliper for opposed-piston disc brakes

Abstract

To realize a caliper for a facing piston type disc brake which secures rigidity and achieves reduction of the weight.SOLUTION: A band-like outer side reinforcement rib 17b is provided at an outer body 6 forming a caliper 2. The outer side reinforcement rib 17b is connected at both circumferential ends to a turn-in side connection part 7 and a turn-out side connection part 8 and covers bottom portions 16a, 16b, 16c of outer cylinder portions 14a, 14b, 14c from an axially outer side so as to cross the bottom portions 16a, 16b, 16c in a circumferential direction. Bottomed cut-out portions 18a, 18b recessed in an axial direction are provided on circumferentially outer side portions of the outer side reinforcement rib 17b.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a caliper that constitutes an opposed piston type disc brake device.

Background Art

[0002] Disk brake devices are widely used to brake automobiles and motorcycles. When braking with a disk brake device, a pair of pads arranged on both axial sides of a rotor that rotates together with a wheel are pressed against both axial side surfaces of the rotor by pistons. As such disk brake devices, various structures have been conventionally known, but an opposed piston type disk brake device having pistons on both axial sides of a rotor has an increasing number of usage examples in recent years because stable braking force can be obtained.

[0003] An opposed piston type disk brake device is arranged to cover a rotor that rotates together with a wheel from the radially outer side, and includes a caliper fixed to a vehicle body, and a pair of pads that are supported so as to be axially movable with respect to the caliper and are arranged on both axial sides of the rotor.

[0004] A caliper that constitutes a disk brake device for an automobile includes an inner body arranged on the inner side in the axial direction of the rotor, an outer body arranged on the outer side in the axial direction of the rotor, and an inward side connecting portion and an outward side connecting portion that are arranged on the radially outer side of the outer peripheral edge of the rotor and connect both outer ends in the circumferential direction of the inner body and both outer ends in the circumferential direction of the outer body.

[0005] The inner body has an inner cylinder portion, and an inner piston is fitted in the inner cylinder portion. The inner cylinder portion opens to the outer axial surface of the inner body facing the rotor. The outer body has an outer cylinder portion, and an outer piston is fitted in the outer cylinder portion. The outer cylinder portion opens to the inner axial surface of the outer body facing the rotor.

[0006] During braking, brake fluid is supplied from the master cylinder to both the inner and outer cylinder sections. This pushes the inner piston, fitted into the inner cylinder section, axially, pressing the pads, supported by the inner body, against the axially inner surface of the rotor. Similarly, the outer piston, fitted into the outer cylinder section, is pushed axially, pressing the pads, supported by the outer body, against the axially outer surface of the rotor. As a result, the rotor is firmly gripped from both axial sides by the pair of pads, and the vehicle is braked.

[0007] During braking, the inner and outer pistons press a pair of pads against both sides of the rotor in the axial direction, and as a reaction, a force is applied to both the inner and outer bodies in the axial direction, separating them from each other. Therefore, if the caliper's rigidity is insufficient, these inner and outer bodies may elastically deform in the axial direction, potentially preventing the desired braking force from being achieved. Furthermore, if the caliper's rigidity is insufficient, during braking, the outer body may elastically deform in the direction of the rotor's rotation relative to the inner body, potentially generating vibration and noise.

[0008] In light of these circumstances, for example, Japanese Patent Publication No. 2012-514166 (Patent Document 1) discloses a structure in which band-shaped (strip-shaped) reinforcing ribs are provided on the axially outer portion of the outer body. Specifically, in the conventional structure described in Japanese Patent Publication No. 2012-514166, band-shaped reinforcing ribs are provided to connect the outer ends on both sides in the circumferential direction to the inlet-side connecting portion and the outlet-side connecting portion, and these reinforcing ribs cover the bottom portions of the two outer cylinder portions provided on the outer body from the axially outer side. In a conventional structure having such a configuration, the rigidity of the outer body can be improved. This is advantageous in terms of obtaining the desired braking force, as well as in suppressing the generation of vibration and noise. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Special Publication No. 2012-514166 [Overview of the project] [Problems that the invention aims to solve]

[0010] Since the disc brake system is located on the road surface side of the vehicle, below the springs that make up the suspension system, it becomes part of the unsprung weight. For this reason, the calipers that make up the disc brake system are required to be lightweight in order to improve the vehicle's fuel efficiency and driving performance. However, the conventional structure described in Japanese Patent Publication No. 2012-514166 still has room for improvement in terms of achieving both rigidity and weight reduction.

[0011] The present invention was made to solve the above problems, and aims to provide a caliper for opposed-piston type disc brakes that can achieve both rigidity and weight reduction. [Means for solving the problem]

[0012] The opposing piston type disc brake caliper of the present invention comprises an inner body, an outer body, an inlet-side connecting portion, and an outlet-side connecting portion. The inner body has an inner cylinder portion and is positioned axially inward of the rotor. The outer body has an outer cylinder portion and is positioned axially outward from the rotor. The entry-side connecting portion and the exit-side connecting portion are positioned radially outward from the outer peripheral edge of the rotor and connect the outer ends of the inner body and the outer ends of the outer body in the circumferential direction in the axial direction. The inlet-side connecting portion and the outlet-side connecting portion each have a rotor path portion on their inner circumferential surface. The outer body is provided with band-shaped reinforcing ribs that are connected to the entry-side connecting portion and the exit-side connecting portion at both outer ends in the circumferential direction, and cover the bottom of the outer cylinder portion from the axial outside so as to cross in the circumferential direction. The reinforcing rib has a bottomed or bottomless recessed portion in the axial direction, that is, a portion that opens outward in the axial direction, on at least one of the two outer portions in the circumferential direction. The aforementioned material-reduced portion is located in the radially intermediate part of the reinforcing rib, has a circumferentially elongated shape, and is positioned axially outward from the rotor path portion. The reinforcing rib has side ribs extending in the circumferential direction on both radial sides of the missing portion. The aforementioned side ribs consist of two or more in total, and each extends in a direction that approaches the central axis of the outer cylinder portion as it moves inward in the circumferential direction. Of the multiple side ribs, the side rib positioned radially outward of the missing portion has its circumferentially outward end connected to the circumferentially inward portion of the inward-facing connecting portion or the outward-facing connecting portion, and is inclined radially inward as it moves circumferentially inward, and its radial thickness is greater than that of the side rib positioned radially inward of the missing portion. Of the multiple side ribs, the side rib positioned radially inward of the missing portion has its circumferentially outer end connected to the circumferentially outer end of the inward-facing connecting portion or the outward-facing connecting portion, and is inclined radially outward as it moves circumferentially inward.

[0013] In a caliper for an opposed-piston type disc brake according to one aspect of the present invention, the side rib, which is located radially inward of the missing material portion when viewed from radially outward, can be made to protrude outward from the side rib, which is located radially outward of the missing material portion.

[0014] In a caliper for an opposing piston type disc brake according to one aspect of the present invention, the reinforcing rib has a flat design surface formed by the axial outer surface of the reinforcing rib on its circumferentially inner portion, and the design surface and the axial outer surface of the side rib can be smoothly connected without any steps.

[0015] In one aspect of the present invention, the opposing piston type disc brake caliper can be made to incline the axial outer surface of each of the side ribs in a direction that increases from the circumferential outer surface toward the axial inner surface toward the outer surface toward the outer surface toward the circumferential side.

[0016] In one aspect of the present invention, a caliper for an opposed-piston type disc brake can have at least one of the side ribs equipped with a passage for brake fluid to pass through inside.

[0017] In the caliper for the opposed piston type disc brake according to one aspect of the present invention, the recessed portions can be provided one by one at the radial intermediate portions on both outer circumferential sides of the reinforcing ribs, and each of the recessed portions can have a substantially triangular shape when viewed axially and can have a larger radial width toward the outer circumferential direction. And, the portion of the reinforcing rib excluding the recessed portion can have a substantially X-shaped configuration when viewed axially. In this case, the axial thickness of the portion of the reinforcing rib excluding the recessed portion can be made larger at the portion deviated outward in the circumferential direction from the outer cylinder portion than at the portion covering the bottom of the outer cylinder portion.

[0018] In the caliper for the opposed piston type disc brake according to one aspect of the present invention, the recessed portion can have a bottom, that is, can be a concave portion (bottomed hole). Alternatively, the recessed portion can be bottomless, that is, can be a through hole.

Advantages of the Invention

[0019] According to the caliper for the opposed piston type disc brake of the present invention, it is possible to achieve both ensuring rigidity and weight reduction.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a plan view of an opposed piston type disc brake device according to an example of an embodiment as viewed from the radially outer side. [Figure 2] FIG. 2 is a front view of the opposed piston type disc brake device according to the first example of the embodiment with the caliper taken out as viewed from the axially outer side. [Figure 3] FIG. 3 is a rear view of the opposed piston type disc brake device according to the first example of the embodiment with the caliper taken out as viewed from the axially inner side. [Figure 4] FIG. 4 is an end view of the opposed piston type disc brake device according to the first example of the embodiment with the caliper taken out as viewed from the retracting side. [Figure 5]Figure 5 is an end view taken from the discharge side of a caliper removed from a opposed-piston type disc brake device according to the first embodiment. [Figure 6] Figure 6 is a bottom view taken from the radially inner side of a caliper removed from a first example of an opposed-piston type disc brake device according to the embodiment. [Figure 7] Figure 7 is a perspective view showing a caliper removed from a first example of an opposed-piston type disc brake device according to the embodiment. [Figure 8] Figure 8 is a perspective view taken from the radially outer side of a caliper removed from a first example of an opposed-piston type disc brake device according to the embodiment. [Figure 9] Figure 9 is a diagram corresponding to Figure 2, showing a second example of the embodiment. [Figure 10] Figure 10 is a diagram corresponding to Figure 2, showing a third example of the embodiment. [Figure 11] Figure 11 is a diagram corresponding to Figure 2, showing a reference example relating to the present invention. [Figure 12] Figure 12 is a diagram corresponding to Figure 7, showing a reference example relating to the present invention. [Modes for carrying out the invention]

[0021] [First example of an embodiment] A first example of the embodiment will be described using Figures 1 to 8.

[0022] The opposed-piston disc brake system 1 in this example is used for automobiles and comprises a caliper 2 and a pair of pads 3 (inner pad and outer pad).

[0023] In this specification and in the claims, "axial direction," "circumferential direction," and "radial direction" refer to the axial, circumferential, and radial directions of the disc-shaped rotor 4 (see Figure 1), unless otherwise specified. Furthermore, the inner circumferential direction refers to the circumferential center side of the opposed piston type disc brake device 1, and the outer circumferential direction refers to both sides of the opposed piston type disc brake device 1 in the circumferential direction. Furthermore, the entry side refers to the side of the outer circumferential direction on which the rotor 4, which rotates with the wheel when the vehicle is moving forward, enters the inside of the caliper 2, and the exit side refers to the side of the outer circumferential direction on which the rotor 4 exits to the outside of the caliper 2.

[0024] <Caliper> The caliper 2 is positioned to cover the rotor 4 from the radially outer side and supports a pair of pads 3 so that they can move in the axial direction (up and down direction in Figures 1, 6, and 8, front and back direction in Figures 2 and 3, and left and right direction in Figures 4 and 5). It is integrally formed from a light alloy such as aluminum alloy or an iron-based alloy by forging or other processes.

[0025] The caliper 2 has an overall boat-shaped form and a roughly bow-shaped form when viewed in the axial direction. The caliper 2 includes an inner body 5 and an outer body 6 arranged to sandwich the rotor 4 from both sides in the axial direction, and an inlet-side connecting portion 7 and an outlet-side connecting portion 8 that connect the outer ends of both the inner and outer bodies 5 and 6 in the circumferential direction in the axial direction.

[0026] 《Inner Body》 The inner body 5 is positioned axially inward of the rotor 4. The inner body 5 comprises three inner cylinder sections 9a, 9b, and 9c, and two mounting holes 10a and 10b.

[0027] The three inner cylinder sections 9a, 9b, and 9c are spaced apart in the circumferential direction. Each of the inner cylinder sections 9a, 9b, and 9c is constructed as a bottomed cylindrical shape and has a substantially cylindrical cylinder space inside. An inner piston (not shown) is fitted into the cylinder space of each of the inner cylinder sections 9a, 9b, and 9c so as to be able to move in the axial direction. Each of the inner cylinder sections 9a, 9b, and 9c is located on the circumferential inner side of the inner body 5 and opens onto the axial outer surface of the inner body 5 facing the rotor 4.

[0028] The inner body 5 reveals a portion of the outer shape of the bottomed cylindrical inner cylinder portions 9a, 9b, and 9c. Specifically, as shown in Figure 1, the radially outer surface of the inner body 5 reveals the outer peripheral portions of the cylindrical portions 11a, 11b, and 11c that constitute the inner cylinder portions 9a, 9b, and 9c. Also, as shown in Figure 6, the radially inner surface of the inner body 5 reveals the inner peripheral portions of the cylindrical portions 11a, 11b, and 11c that constitute the inner cylinder portions 9a, 9b, and 9c. Furthermore, as shown in Figure 3, the axially inner surface of the inner body 5 reveals the circular bottom portions 12a, 12b, and 12c that constitute the inner cylinder portions 9a, 9b, and 9c.

[0029] In the illustrated example, the cylinder diameters of the three inner cylinder sections 9a, 9b, and 9c are all different. Specifically, the cylinder diameter of the three inner cylinder sections 9a, 9b, and 9c is smallest for inner cylinder section 9a, which is located on the inlet side, and largest for inner cylinder section 9c, which is located on the outlet side.

[0030] The two mounting holes 10a and 10b are located on the outer sides in the circumferential direction of the inner body 5, sandwiching the three inner cylinder portions 9a, 9b, and 9c from both sides in the circumferential direction. The caliper 2 is fixed either directly to the knuckle constituting the vehicle's suspension system or via an adapter (not shown) using bolts (not shown) inserted through the mounting holes 10a and 10b from the radially outer side. Therefore, the caliper 2 in this example is a radially mounted caliper.

[0031] The inner body 5 is provided with an inner reinforcing rib 13 on its axially inner side. The inner reinforcing rib 13 has a greater wall thickness than other parts and is a thick-walled section that protrudes inward in the axial direction. As a result, the inner body 5 has increased wall thickness and improved rigidity in the area where the inner reinforcing rib 13 is provided.

[0032] The inner reinforcing rib 13 is configured as a band extending in the circumferential direction, with both outer ends in the circumferential direction connected to the inlet-side connecting portion 7 and the outlet-side connecting portion 8. The inner reinforcing rib 13 covers the bottom portions 12a, 12b, and 12c, which constitute the inner cylinder portions 9a, 9b, and 9c, respectively, from the axially inward direction, crossing them in the circumferential direction.

[0033] The inner body 5 supports the inner pad 3, which is positioned axially inward of the rotor 4, so that it is axially movable. For this purpose, the inner body 5 has inner overhangs 28 that protrude axially on both circumferential outer portions of its axial outer surface.

[0034] Outer body The outer body 6 is positioned axially outward from the rotor 4. The outer body 6 comprises three outer cylinder sections 14a, 14b, and 14c.

[0035] The three outer cylinder sections 14a, 14b, and 14c are spaced apart in the circumferential direction. Each of the outer cylinder sections 14a, 14b, and 14c is constructed as a bottomed cylindrical shape and has a substantially cylindrical cylinder space inside. An outer piston (not shown) is fitted into the cylinder space of each of the outer cylinder sections 14a, 14b, and 14c so as to be able to move in the axial direction. Each of the outer cylinder sections 14a, 14b, and 14c is located on the circumferential inner side of the outer body 6 and opens onto the axial inner surface of the outer body 6 facing the rotor 4.

[0036] The outer body 6 reveals a portion of the outer shape of the bottomed cylindrical outer cylinder portions 14a, 14b, and 14c. Specifically, as shown in Figure 1, the radial outer surface of the outer body 6 reveals the outer peripheral portions of the cylindrical portions 15a, 15b, and 15c that constitute the outer cylinder portions 14a, 14b, and 14c. Also, as shown in Figure 6, the radial inner surface of the outer body 6 reveals the inner peripheral portions of the cylindrical portions 15a, 15b, and 15c that constitute the outer cylinder portions 14a, 14b, and 14c. Furthermore, as shown in Figure 2, the axial outer surface of the outer body 6 reveals the circular bottom portions 16a, 16b, and 16c that constitute the outer cylinder portions 14a, 14b, and 14c.

[0037] In the illustrated example, the cylinder diameters of the three outer cylinder sections 14a, 14b, and 14c are all different. Specifically, the cylinder diameter of the three outer cylinder sections 14a, 14b, and 14c is smallest for outer cylinder section 14a, which is located on the inlet side, and largest for outer cylinder section 14c, which is located on the outlet side.

[0038] The outer cylinder sections 14a, 14b, and 14c are arranged coaxially with the inner cylinder sections 9a, 9b, and 9c, respectively.

[0039] The outer body 6 is provided with an outer-side reinforcing rib 17 on its axially outer portion. The outer-side reinforcing rib 17 is thicker than other parts and is a thick-walled portion that protrudes axially outward. As a result, the outer body 6 has increased thickness and improved rigidity in the portion where the outer-side reinforcing rib 17 is provided. In this example, the outer-side reinforcing rib 17 corresponds to the reinforcing rib described in the claims.

[0040] The outer reinforcing rib 17 is configured as a band extending in the circumferential direction, with both outer ends in the circumferential direction connected to the inlet-side connecting portion 7 and the outlet-side connecting portion 8. The outer reinforcing rib 17 covers the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c, respectively, from the axial outside, crossing them in the circumferential direction.

[0041] The radially outer surface of the outer reinforcing rib 17 is a partially cylindrical surface that is slightly curved in an arc shape so that the radially inner side is convex. In contrast, the radially inner surface of the circumferential inner part of the outer reinforcing rib 17 is a partially cylindrical surface that is curved in an arc shape so that the radially outer side is convex. As a result, the radial width of the circumferential inner part of the outer reinforcing rib 17 decreases from the circumferential outer side to the circumferential inner side, and is smallest in the part that covers the bottom 16b of the outer cylinder part 14b located in the circumferential middle part.

[0042] The outer reinforcing rib 17 has one axially recessed section (weight-reducing section) 18a and 18b in the radially intermediate portion of both outer sides in the circumferential direction. In this example, each of the weight-reducing sections 18a and 18b is a bottomed recess.

[0043] Each of the missing sections 18a and 18b has a circumferentially elongated shape, with a circumferential width greater than its radial width. Specifically, each of the missing sections 18a and 18b has a roughly triangular shape when viewed axially. The radial width of each of the missing sections 18a and 18b increases as it moves outward in the circumferential direction.

[0044] The material-depleted portion 18a located on the entry side opens outwards in the axial direction and outwards in the circumferential direction (entry side). Similarly, the material-depleted portion 18b located on the exit side opens outwards in the axial direction and outwards in the circumferential direction (exit side).

[0045] In the illustrated example, the inner corner (end) of the circumferentially oriented corner of the defective section 18a located on the entry side is positioned circumferentially outward from the outer cylinder section 14a located on the entry side, and is constructed with a concave curved surface to prevent stress concentration. Similarly, the inner corner of the defective section 18b located on the exit side is also positioned circumferentially outward from the outer cylinder section 14c located on the exit side, and is constructed with a concave curved surface. However, when implementing the present invention, the inner corners of the circumferentially oriented corners of the defective sections on the entry and exit sides can be positioned to overlap with the bottom of the outer cylinder section, or they can be constructed with corners instead of concave curved surfaces.

[0046] In this example, the band-shaped outer reinforcing rib 17 is curved such that the radially outer surface is convex on the radially inner side, and the radially inner surface is curved such that the radially outer side is convex. Furthermore, it has one approximately triangular cut section 18a and 18b in the radial middle of both outer circumferential parts when viewed in the axial direction. As a result, both outer circumferential parts of the outer reinforcing rib 17 have a bifurcated shape, and as a whole, it has an approximately X shape when viewed in the axial direction.

[0047] The axial thickness of the outer reinforcing rib 17 is not constant in the circumferential direction, but varies depending on the circumferential position. Specifically, the axial thickness of the outer reinforcing rib 17, excluding the missing sections 18a and 18b, is greater in the portion that extends circumferentially outward from the bottoms 16a, 16b, and 16c of the outer cylinder sections 14a, 14b, and 14c than in the portion that covers the bottoms 16a, 16b, and 16c of the outer cylinder sections 14a, 14b, and 14c.

[0048] The outer reinforcing rib 17 is provided with two side ribs 19a and 19b on both radial sides of the material-reduced portion 18a located on the inward side, and two side ribs 20a and 20b on both radial sides of the material-reduced portion 18b located on the outward side. Furthermore, the outer reinforcing rib 17 is provided with one center rib 21 between the two side ribs 19a and 19b located on the inward side and the two side ribs 20a and 20b located on the outward side. Therefore, the outer reinforcing rib 17 in this example consists of one center rib 21 that constitutes the circumferential inner part of the outer reinforcing rib 17 and a total of four side ribs 19a, 19b, 20a, and 20b that constitute the circumferential outer parts of the outer reinforcing rib 17.

[0049] Of the two side ribs 19a and 19b positioned on the entry side, the circumferentially outer end of side rib 19a, which is located radially outside the missing portion 18a, is connected to the circumferentially inner portion of the entry side connecting portion 7. Furthermore, the circumferentially inner end of side rib 19a is connected to the circumferentially outer end of the radially outer portion of the center rib 21. In contrast, of the two side ribs 19a and 19b, the circumferentially outer end of side rib 19b, which is located radially inside the missing portion 18a, is located circumferentially further out than the circumferentially outer end of side rib 19a, and is connected to the circumferentially outer end of the entry side connecting portion 7. Also, the circumferentially inner end of side rib 19b is connected to the circumferentially outer end of the radially inner portion of the center rib 21 at approximately the same circumferential position (X1 position) as the circumferentially inner end of side rib 19a. Furthermore, when implementing the present invention, the circumferential inner portion of the side rib can be connected to the circumferential outer end of the center rib, and it can also be directly connected to the cylindrical portion of the outer cylinder on the entry side.

[0050] The two side ribs 19a and 19b have slightly different radial thicknesses. Specifically, in the same circumferential position, the radial thickness of the side rib 19a located radially outside the missing portion 18a is slightly greater than the radial thickness of the side rib 19b located radially inside the missing portion 18a. Also, as shown in Figure 1, when the caliper 2 is viewed from the radial outside, a portion of the side rib 19b located radially inside the missing portion 18a protrudes slightly outward from the side rib 19a located radially outside the missing portion 18a. When implementing the present invention, it is also possible to have most of the side rib located radially inside the missing portion protrude outward from the side rib located radially outside the missing portion.

[0051] Each of the two side ribs 19a and 19b positioned on the entry side is aligned with the central axis O of the outer cylinder portion 14a positioned on the entry side. 14aThey extend in a direction that approaches the circumferential direction. For this reason, the two side ribs 19a and 19b are arranged non-parallel to each other. The side rib 19a, which is positioned radially outward, is inclined radially inward as it moves circumferentially inward. In contrast, the side rib 19b, which is positioned radially inward, is inclined radially outward as it moves circumferentially inward. The inclination angle between the two side ribs 19a and 19b is approximately 10° to 60°, more preferably approximately 20° to 50°.

[0052] The axial outer surfaces of the side ribs 19a and 19b are inclined approximately linearly, with the inward axial direction increasing as the outward circumferential direction increases.

[0053] Of the two side ribs 20a and 20b positioned on the exit side, the circumferentially outer end of side rib 20a, which is positioned radially outside the missing portion 18b, is connected to the circumferentially inner portion of the exit side connecting portion 8. Furthermore, the circumferentially inner end of side rib 20a is connected to the circumferentially outer end of the radially outer portion of the center rib 21. In contrast, of the two side ribs 20a and 20b, the circumferentially outer end of side rib 20b, which is positioned radially inside the missing portion 18b, is located circumferentially further out than the circumferentially outer end of side rib 20a, and is connected to the circumferentially outer end of the exit side connecting portion 8. Also, the circumferentially inner end of side rib 20b is connected to the circumferentially outer end of the radially inner portion of the center rib 21 at approximately the same circumferential position (X2 position) as the circumferentially inner end of side rib 20a. Furthermore, when implementing the present invention, the circumferential inner portion of the side rib can be connected to the circumferential outer end of the center rib, and also directly connected to the cylindrical portion of the outer cylinder on the discharge side.

[0054] The two side ribs 20a and 20b have slightly different radial thicknesses. Specifically, in the same circumferential position, the radial thickness of the side rib 20a located radially outside the missing portion 18b is slightly greater than the radial thickness of the side rib 20b located radially inside the missing portion 18b. Also, as shown in Figure 1, when the caliper 2 is viewed from the radial outside, a portion of the side rib 20b located radially inside the missing portion 18b slightly protrudes outward from the side rib 20a located radially outside the missing portion 18b. When implementing the present invention, it is also possible to have most of the side rib located radially inside the missing portion protrude outward from the side rib located radially outside the missing portion.

[0055] Each of the two side ribs 20a and 20b located on the rotating side is aligned with the central axis O of the outer cylinder portion 14c located on the rotating side. 14c They extend in a direction that approaches the circumferential direction. For this reason, the two side ribs 20a and 20b are arranged non-parallel to each other. The side rib 20a, which is positioned radially outward, is inclined radially inward as it moves circumferentially inward. In contrast, the side rib 20b, which is positioned radially inward, is inclined radially outward as it moves circumferentially inward. The inclination angle between the two side ribs 20a and 20b is the same as the inclination angle between the two side ribs 19a and 19b, which are positioned on the inlet side.

[0056] The axial outer surfaces of the side ribs 20a and 20b are inclined approximately linearly in the direction from the circumferential outer side toward the axial inner side.

[0057] The outer reinforcing rib 17 in this example has a symmetrical shape with respect to the axial direction. Therefore, the two side ribs 19a and 19b located on the inlet side and the two side ribs 20a and 20b located on the outlet side have a symmetrical shape with respect to the axial direction.

[0058] The center rib 21 is located on the circumferential inner portion (intermediate portion) of the outer reinforcing rib 17. The center rib 21 extends in the circumferential direction and covers the radial intermediate portion of the bottom portions 16a, 16b, and 16c of the three outer cylinder portions 14a, 14b, and 14c from the axial outer side, traversing in the circumferential direction. As a result, the radially outer and radially inner portions of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c are not covered by the center rib 21 and protrude radially from the center rib 21.

[0059] The radial width of the center rib 21 is greater than the radial widths of the side ribs 19a, 19b, 20a, and 20b, respectively, and smaller than the diameters of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c. Specifically, the radial width of the center rib 21 is approximately 2 to 3 times the radial width of the side ribs 19a, 19b, 20a, and 20b at the outermost circumferential portions with the largest radial width, and approximately 1.2 to 1.5 times the radial width of the side ribs 19a, 19b, 20a, and 20b at the central circumferential portion with the smallest radial width.

[0060] The outer ends of the center rib 21 in the circumferential direction are connected in the circumferential direction to the inner ends of the side ribs 19a and 19b located on the inward side, and to the inner ends of the side ribs 20a and 20b located on the outward side. The boundary position between the outer end of the center rib 21 on the inward side and the inner ends of the side ribs 19a and 19b located on the inward side is indicated by X1 in Figure 2, and the boundary position between the outer end of the center rib 21 on the outward side and the inner ends of the side ribs 20a and 20b located on the outward side is indicated by X2 in Figure 2.

[0061] The center rib 21 has a flat design surface 22 at the circumferential center of its axial outer surface, which can be used to display characters, figures, etc., and curved portions 23 on both circumferential outer sides of its axial outer surface. The design surface 22 of the center rib 21 and the axial outer surfaces of the four side ribs 19a, 19b, 20a, and 20b are smoothly connected without steps via the curved portions 23. In addition, when implementing the present invention, the design surface of the center rib and the axial outer surfaces of the side ribs can also be directly and smoothly connected without steps.

[0062] The radially outer surface of the center rib 21 is a partially cylindrical surface that is slightly curved in an arc shape so that the radially inner side is convex, and the radially inner surface of the center rib 21 is a partially cylindrical surface that is curved in an arc shape so that the radially outer side is convex. In this example, the radially outer surface of the center rib 21 and the radially outer surfaces of a pair of side ribs 19a and 20a located on the radially outer side are smoothly connected in the circumferential direction. In addition, the radially inner surface of the center rib 21 and the radially inner surfaces of a pair of side ribs 19b and 20b located on the radially inner side are smoothly connected in the circumferential direction.

[0063] The outer body 6 supports the pads 3, which are positioned axially outward from the rotor 4, so that they can move in the axial direction. For this purpose, the outer body 6 has outer-side overhangs 29 that protrude in the axial direction on both circumferential outer portions of its axially inner surface.

[0064] 《Inlet-side connecting section and outlet-side connecting section》 The entry-side connecting portion 7 and the exit-side connecting portion 8 are positioned radially outward from the outer peripheral edge of the rotor 4. The entry-side connecting portion 7 axially connects the entry-side outer circumferential end of the inner body 5 to the entry-side outer circumferential end of the outer body 6. The exit-side connecting portion 8 axially connects the exit-side outer circumferential end of the inner body 5 to the exit-side outer circumferential end of the outer body 6. The entry-side connecting portion 7 and the exit-side connecting portion 8 have a partially cylindrical shape that is curved in an arc, and cover the rotor 4 from the radially outward side. The inner circumferential surfaces of the entry-side connecting portion 7 and the exit-side connecting portion 8 are provided with rotor path portions 24, which are recesses for the outer peripheral edge of the rotor 4 to enter. The area surrounded on all four sides by the inner and outer bodies 5 and 6 and the entry-side and exit-side connecting portions 7 and 8 forms a radially penetrating, substantially rectangular opening 25 in plan view.

[0065] 《Communication path》 As shown in Figure 8, the caliper 2 is equipped with a passage 26 for the passage of brake fluid. Brake fluid is supplied to the passage 26 from the master cylinder. The passage 26 consists of a total of eight through holes, from the first through hole 27a to the eighth through hole 27h.

[0066] Each of the first through-holes 27a to the third through-holes 27c is located inside the inner body 5. The first through-hole 27a extends linearly in the circumferential direction, crossing each of the inner cylinder portions 9a, 9b, and 9c. The second through-hole 27b is located on the inward side of the inward-side inner cylinder portion 9a and communicates with the first through-hole 27a. The second through-hole 27b extends diagonally in the direction toward the inward side as it moves axially outward. The third through-hole 27c is mostly located on the outward side of the outward-side inner cylinder portion 9c and communicates with the first through-hole 27a. The third through-hole 27c extends diagonally in the direction toward the outward side as it moves axially outward.

[0067] The fourth through-hole 27d is located inside the inlet-side connecting portion 7 and extends in the axial direction. The axially inner portion of the fourth through-hole 27d communicates with the second through-hole 27b. The fifth through-hole 27e is located inside the outlet-side connecting portion 8 and extends in the axial direction. The axially inner portion of the fifth through-hole 27e communicates with the third through-hole 27c.

[0068] Each of the 6th through-hole 27f to the 8th through-hole 27h is located inside the outer body 6. The 6th through-hole 27f extends linearly in the circumferential direction, crossing each of the outer cylinder portions 14a, 14b, and 14c. The 7th through-hole 27g is located on the inward side of the inward-side outer cylinder portion 14a and communicates with each of the 4th through-hole 27d and the 6th through-hole 27f. The 7th through-hole 27g extends diagonally in the direction toward the inward side as it moves axially inward. The 8th through-hole 27h is mostly located on the outward side of the outward-side outer cylinder portion 14c and communicates with each of the 5th through-hole 27e and the 6th through-hole 27f. The 8th through-hole 27h extends diagonally in the direction toward the outward side as it moves axially inward.

[0069] In this example, a seventh through-hole 27g, which constitutes the communication passage 26, is formed inside the radially outer side rib 19a of the pair of side ribs 19a and 19b arranged on the entry side. The seventh through-hole 27g is open on the axially outer surface of the side rib 19a. In addition, an eighth through-hole 27h, which constitutes the communication passage 26, is formed inside the radially outer side rib 20a of the pair of side ribs 20a and 20b arranged on the exit side. The eighth through-hole 27h is open on the axially outer surface of the side rib 20a.

[0070] <pad> As shown in Figure 1, each of the pair of pads 3 consists of a lining (friction material) 30 and a metal backing plate (pressure plate) 31 that supports the back surface of the lining 30.

[0071] In this example, the inner pad 3 (inner pad), which is positioned axially inward of the rotor 4, is placed between a pair of inner protrusions 28, and the outer ends of both sides in the circumferential direction of the backing plate 31 constituting the inner pad 3 are engaged with the pair of inner protrusions 28 so as to allow axial movement. This supports the inner pad 3 so as to be axially movable relative to the inner body 5.

[0072] Furthermore, the outer pad 3 (outer pad), which is positioned on the axially outer side of the rotor 4, is placed between a pair of outer protrusions 29, and the circumferential outer ends of the backing plate 31 constituting the outer pad 3 are engaged with the pair of outer protrusions 29 so as to allow axial movement. In this way, the outer pad 3 is supported so as to be axially movable relative to the outer body 6.

[0073] Although not shown in the diagram, pad clips can also be interposed between the circumferential outer surfaces of the backing plate 31 that constitutes each of the pair of pads 3 and the circumferential inner surfaces of the inner protrusion 28 and the outer protrusion 29, respectively. When implementing the present invention, the support structure for the pair of pads 3 to the inner and outer bodies 5 and 6 is not limited to the structure described above, and various conventionally known structures can be adopted.

[0074] In the case of the opposed-piston type disc brake device 1 described above, during braking, brake fluid is supplied from the master cylinder through the communication passage 26 to each of the inner cylinder sections 9a, 9b, 9c and outer cylinder sections 14a, 14b, 14c. This pushes the inner pistons fitted in each of the inner cylinder sections 9a, 9b, 9c in the axial direction, pressing the inner pads 3 supported by the inner body 5 against the axially inner surface of the rotor 4. Similarly, the outer pistons fitted in each of the outer cylinder sections 14a, 14b, 14c are pushed in the axial direction, pressing the outer pads 3 supported by the outer body 6 against the axially outer surface of the rotor 4. As a result, the rotor 4 is strongly gripped from both axial sides by a pair of pads 3, and the vehicle is braked.

[0075] In particular, in this example, it is possible to achieve a high level of balance between ensuring rigidity and reducing weight with respect to the caliper 2 that constitutes the opposed-piston type disc brake system 1.

[0076] [Reasons why rigidity can be improved] In the caliper 2 of this example, the band-shaped outer reinforcing rib 17 (center rib 21) covers the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c from the axial outside. Therefore, the axial rigidity of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c of the outer body 6 can be improved. Consequently, when braking, the elastic deformation of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c in the axial outward direction can be suppressed, and thus the elastic deformation of the inner body 5 and the outer body 6 in the direction of moving away from each other in the axial direction can be suppressed. As a result, the desired braking force can be obtained with the opposed piston type disc brake device 1 of this example. Furthermore, the outer reinforcing rib 17 extends in the circumferential direction, and its ends on both sides in the circumferential direction are connected to the entry-side connecting portion 7 and the exit-side connecting portion 8, thereby improving the circumferential rigidity of the outer body 6. As a result, it is possible to suppress elastic deformation of the outer body 6 so that it is displaced in the circumferential direction (the rotational direction of the rotor 4) relative to the inner body 5 during braking, thereby suppressing vibration and noise.

[0077] Furthermore, in this example, each of the pair of side ribs 19a and 19b, which are located on the circumferential outer portion of the retractable outer reinforcing rib 17, is aligned with the central axis O of the retractable outer cylinder portion 14a. 14a The ribs are extended in a direction that approaches the central axis, and a pair of side ribs 19a and 19b are arranged non-parallel to each other. In addition, each of the pair of side ribs 20a and 20b, which are located on the circumferential outer part of the rotating side of the outer reinforcing rib 17, is aligned with the central axis O of the rotating outer cylinder portion 14c. 14cThe side ribs 20a and 20b are extended in a direction that approaches the axial direction, and are arranged non-parallel to each other. This improves the torsional rigidity of the outer body 6 and suppresses the elastic deformation of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c in the axial direction outward.

[0078] Furthermore, in this example, of the pair of side ribs 19a and 19b arranged on the entry side, the radial thickness of the radially outer side rib 19a is made slightly larger than the radial thickness of the radially inner side rib 19b. Also, of the pair of side ribs 20a and 20b arranged on the exit side, the radial thickness of the radially outer side rib 20a is made slightly larger than the radial thickness of the radially inner side rib 20b. As a result, the radial compressive stress of the radially outer side ribs 19a and 20a can be increased, thereby effectively suppressing the elastic deformation of the outer body 6 in the direction away from the inner body 5 in the axial direction during braking.

[0079] Furthermore, when viewing the caliper 2 from the radially outer side, of the pair of side ribs 19a and 19b located on the entry side, the side rib 19b located on the radially inner side is made to protrude outward from the side rib 19a located on the radially outer side. Similarly, of the pair of side ribs 20a and 20b located on the exit side, the side rib 20b located on the radially inner side is made to protrude outward from the side rib 20a located on the radially outer side. This increases the axial and / or circumferential tensile stress of the side ribs 19b and 20b located on the radially inner side, thereby effectively suppressing the elastic deformation of the outer body 6 in the direction away from the inner body 5 in the axial direction during braking.

[0080] [Reasons why weight reduction is possible] In this example, the caliper 2 has material-reduced sections 18a and 18b on both circumferential outer sides of the outer reinforcing rib 17. In other words, in areas that do not sufficiently contribute to improving rigidity, the outer reinforcing rib is omitted, and material-reduced sections 18a and 18b are provided instead. This makes it possible to reduce the weight of the caliper 2 while ensuring its rigidity. In particular, in this example, the material-reduced sections 18a and 18b are provided in areas that are circumferentially outward from the bottoms 16a and 16c of the outer cylinder sections 14a and 14c, respectively, so that the bottoms 16a, 16b, and 16c are sufficiently reinforced while reducing weight.

[0081] Furthermore, the radial width of the center rib 21 that constitutes the outer side reinforcing rib 17 is made smaller than the diameter of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c, respectively, so that the center rib 21 covers only the radially intermediate portions of the bottom portions 16a, 16b, and 16c of the outer cylinder portions 14a, 14b, and 14c. Therefore, by providing the outer side reinforcing rib 17, it is possible to prevent the weight of the caliper 2 from increasing unnecessarily.

[0082] Furthermore, in this example, a seventh through-hole 27g constituting the communication passage 26 is formed inside the side rib 19a located on the inlet side and radially outward, and an eighth through-hole 27h constituting the communication passage 26 is formed inside the side rib 20a located on the outlet side and radially outward. As a result, it is not necessary to provide external piping for the passage of brake fluid, thus reducing the number of parts and weight.

[0083] As a result, caliper 2 in this example can achieve a high level of balance between ensuring rigidity and reducing weight.

[0084] Furthermore, in this example, the design surface 22 of the center rib 21 and the axial outer surfaces of the four side ribs 19a, 19b, 20a, and 20b are smoothly connected without any steps via the curved surface portion 23. This improves the aesthetic appearance of the caliper 2 from the axial outer side. It also suppresses stress concentration at the connection point between the center rib 21 and the side ribs 19a, 19b, 20a, and 20b.

[0085] [Second example of an embodiment] A second example of the embodiment will be described with reference to Figure 9.

[0086] In this example, only the structure of the outermost portions on both sides in the circumferential direction of the outer reinforcing rib 17a is modified compared to the structure of the first example of the embodiment.

[0087] Specifically, in this example, two bottomed, depleted sections 18c and 18d are provided radially in the middle of the radial direction of the circumferential outer portion on the entry side of the outer reinforcing rib 17a, and two bottomed, depleted sections 18e and 18f are provided radially in the middle of the radial direction of the circumferential outer portion on the exit side of the outer reinforcing rib 17a.

[0088] Each of the four missing sections 18c to 18f has a circumferentially elongated shape, with a circumferential width greater than its radial width. Specifically, each of the four missing sections 18c to 18f has a roughly triangular shape when viewed axially. The radial width of each of the missing sections 18c to 18f increases towards the circumferential outer edge.

[0089] Of the two defective sections 18c and 18d located on the entry side, the defective section 18d located radially inward has a longer circumferential length than the defective section 18c located radially outward. The circumferential outer end of the defective section 18d located radially inward is located circumferentially outward than the circumferential outer end of the defective section 18c located radially outward. Also, of the two defective sections 18e and 18f located on the exit side, the defective section 18f located radially inward has a longer circumferential length than the defective section 18e located radially outward. The circumferential outer end of the defective section 18f located radially inward is located circumferentially outward than the circumferential outer end of the defective section 18e located radially outward.

[0090] The outer reinforcing rib 17a is provided with three side ribs 19c, 19d, and 19e so as to sandwich each of the two missing sections 18c and 18d located on the inward side from both radial sides. Specifically, the side ribs 19c and 19d are provided on both radial sides of the radially outer missing section 18c, and the side ribs 19d and 19e are provided on both radial sides of the radially inner missing section 18d. In addition, the outer reinforcing rib 17a is provided with three side ribs 20c, 20d, and 20e so as to sandwich each of the two missing sections 18e and 18f located on the outward side from both radial sides. Specifically, the side ribs 20c and 20d are provided on both radial sides of the radially outer missing section 18e, and the side ribs 20d and 20e are provided on both radial sides of the radially inner missing section 18f. Therefore, the outer reinforcing rib 17a in this example has a total of six side ribs 19c, 19d, 19e, 20c, 20d, and 20e.

[0091] The three side ribs 19c, 19d, and 19e located on the entry side are arranged non-parallel to each other. The side rib 19c, located on the radially outer side, is inclined radially inward as it moves circumferentially inward. In contrast, the side rib 19d, located in the radial middle section, and the side rib 19e, located on the radially inner side, are inclined radially outward as they move circumferentially inward.

[0092] The circumferential outer end of the side rib 19c, which is positioned radially outward, is connected to the circumferential inner part of the entry-side connecting portion 7. The circumferential outer end of the side rib 19d, which is positioned radially in the middle, is connected to the circumferential middle part of the entry-side connecting portion 7. The circumferential outer end of the side rib 19e, which is positioned radially inward, is connected to the circumferential outer end of the entry-side connecting portion 7. The circumferential inner ends of the three side ribs 19c, 19d, and 19e, which are positioned on the entry side, are connected to the circumferential outer end of the entry side of the center rib 21.

[0093] The three side ribs 20c, 20d, and 20e, located on the exit side, are arranged non-parallel to each other. The side rib 20c, located on the radially outer side, is inclined radially inward as it moves circumferentially inward. In contrast, the side rib 20d, located in the radial middle section, and the side rib 20e, located on the radially inner side, are inclined radially outward as they move circumferentially inward.

[0094] The circumferential outer end of the side rib 20c, which is positioned radially outward, is connected to the circumferential inner part of the outlet-side connecting portion 8. The circumferential outer end of the side rib 20d, which is positioned radially in the middle, is connected to the circumferential middle part of the outlet-side connecting portion 8. The circumferential outer end of the side rib 20e, which is positioned radially inward, is connected to the circumferential outer end of the outlet-side connecting portion 8. The circumferential inner ends of the three side ribs 20c, 20d, and 20e, which are positioned on the outlet side, are connected to the circumferential outer end of the outlet side of the center rib 21.

[0095] In this example, compared to the structure of the first embodiment, the number of material-reduced sections can be increased by two, thus enabling further weight reduction of the caliper 2. The other configurations and effects are the same as in the first example of the embodiment.

[0096] [Third example of an embodiment] A third example of the embodiment will be described with reference to Figure 10.

[0097] In this example, only the structure of the outermost parts on both sides in the circumferential direction of the outer reinforcing rib 17b is changed compared to the structure of the first example of the embodiment.

[0098] Specifically, the outer reinforcing rib 17b in this example further has a radial rib 32a that radially connects the circumferential intermediate portions of the two side ribs 19a, 19b located on the inlet side. The radial rib 32a divides the gap 18a (see Figure 2) between the two side ribs 19a, 19b into two in the circumferential direction. In other words, the outer reinforcing rib 17b has two gaps 18g, 18h arranged circumferentially between the two side ribs 19a, 19b. Of the two gaps 18g, 18h, the gap 18g located on the circumferential inner side opens only axially outward, while the gap 18h located on the circumferential outer side opens both axially outward and circumferentially outward.

[0099] Furthermore, the outer reinforcing rib 17b has a radial rib 32b that radially connects the circumferential intermediate portions of the two side ribs 20a and 20b, which are located on the outward side. The radial rib 32b divides the gap 18b (see Figure 2) between the two side ribs 20a and 20b into two in the circumferential direction. In other words, the outer reinforcing rib 17b has two gaps 18i and 18j arranged circumferentially between the two side ribs 20a and 20b. Of the two gaps 18i and 18j, the gap 18i located on the circumferential inner side opens only axially outward, while the gap 18j located on the circumferential outer side opens both axially outward and circumferentially outward.

[0100] In this example, the two side ribs 19a and 19b positioned on the entry side are radially connected by the radial rib 32a, and the two side ribs 20a and 20b positioned on the exit side are radially connected by the radial rib 32b, thereby further improving the rigidity of the outer body 6. As a result, elastic deformation of the outer body 6 away from the inner body 5 in the axial direction during braking can be effectively suppressed. The other configurations and effects are the same as in the first example of the embodiment.

[0101] [ Reference example ] Reference examples relating to the present invention This will be explained using Figures 11 and 12.

[0102] Book reference In this example, the only change made from the structure of the first embodiment is the structure of the material-reducing portions 33a and 33b provided on both circumferential outer sides of the outer reinforcing rib 17c.

[0103] Specifically, this reference In this example, a bottomless, hollowed-out section 33a, which is a through hole, is provided in the radially intermediate portion of the circumferential outer part on the entry side of the outer reinforcing rib 17c, and a bottomless, hollowed-out section 33b, which is a through hole, is provided in the radially intermediate portion of the circumferential outer part on the exit side of the outer reinforcing rib 17c.

[0104] Each of the missing portions 33a and 33b is a triangular hole having a roughly right-angled triangular shape in an axial view. Each of the missing portions 33a and 33b has a greater axial depth and a shorter circumferential dimension compared to the bottomed missing portions 18a and 18b of the first example of the embodiment (see Figure 2).

[0105] The above books reference In this example, the missing sections 33a and 33b provided on both circumferential outer sides of the outer reinforcing rib 17c are each made into bottomless through holes. Therefore, when the structure of the first embodiment and the weight of the caliper 2 are the same, the circumferential dimensions of the missing sections 33a and 33b can be shortened compared to the structure of the first embodiment. As a result, the irregularities on the axial outer surface of the outer body 6 can be reduced, improving the freedom of design. Furthermore, the heat dissipation effect of the caliper 2 can also be improved. The other configurations and effects are the same as in the first example of the embodiment.

[0106] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention. Furthermore, each of the embodiments is also described. and reference examples The structure can be combined and implemented as appropriate, as long as it does not create contradictions.

[0107] Examples of the Embodiments and reference examples We have now described a structure in which a gap is provided on both outer sides in the circumferential direction of the outer reinforcing rib. However, when implementing the present invention, the arrangement and number of gaps will vary depending on the embodiment. and reference examples The present invention is not limited to the structure shown. For example, when implementing the present invention, the material-removed portion may be provided only on the circumferential outer portion of the inlet side, or only on the circumferential outer portion of the outlet side. Furthermore, when providing multiple material-removed portions, a combination of bottomed and bottomless material-removed portions may be provided. In addition, the number and shape of the material-removed portions provided on the circumferential outer portion of the inlet side may be different from the number and shape of the material-removed portions provided on the circumferential outer portion of the outlet side.

[0108] When implementing the present invention, the opposing piston type disc brake caliper may be a monocoque structure (integrated structure) integrally constructed from a material such as an aluminum alloy, or it may be a structure in which the inner body and outer body are connected by bolts. Furthermore, the number of inner cylinders and outer cylinders is not limited to the three described in the embodiment, but may be one, two, or four or more. [Explanation of symbols]

[0109] 1. Opposed piston type disc brake system 2 Caliper 3 pads 4 rotors 5 Inner Body 6 Outer Body 7 Entry side connection part 8 Output side connection part 9a, 9b, 9c Inner cylinder section 10a, 10b Mounting holes 11a, 11b, 11c cylinder part 12a, 12b, 12c bottom 13. Inner reinforcing rib 14a, 14b, 14c Outer cylinder section 15a, 15b, 15c cylinder part 16a, 16b, 16c bottom 17, 17a~17c Outer side reinforcing ribs 18a~18j Missing part 19a~19e Side Ribs 20a~20e Side Ribs 21 Center Rib 22 Design surface 23 Curved part 24. Rotor path section 25 Opening 26 Communication path 27a~27h 1st through hole ~ 8th through hole 28 Inner side protrusion 29 Outer side protrusion 30 lining 31 Backing 32a, 32b Radial ribs 33a, 33b missing part

Claims

1. An inner body having an inner cylinder section and positioned axially inward of the rotor, An outer body having an outer cylinder portion and positioned axially outward of the rotor, The rotor comprises an inlet-side connecting portion and an outlet-side connecting portion, which are arranged radially outward from the outer peripheral edge of the rotor and axially connect the outer ends of the inner body and the outer ends of the outer body. The aforementioned inlet-side connecting portion and the aforementioned outlet-side connecting portion each have a rotor path portion on their inner circumferential surface. The outer body has band-shaped reinforcing ribs that are connected to the entry-side connecting portion and the exit-side connecting portion at both outer ends in the circumferential direction, and cover the bottom of the outer cylinder portion from the axial outside so as to cross in the circumferential direction. The reinforcing rib has a recessed, bottomed or bottomless portion on at least one of its outer circumferential portions, The aforementioned material-reduced portion is located in the radially intermediate part of the reinforcing rib, has a circumferentially elongated shape, and is positioned axially outward from the rotor path portion. The reinforcing rib has side ribs extending in the circumferential direction on both radial sides of the missing portion, The aforementioned side ribs are provided in a total of two or more, and each extends in a direction that approaches the central axis of the outer cylinder portion as it moves inward in the circumferential direction. Of the multiple side ribs, the side rib positioned radially outward of the missing portion has its circumferentially outward end connected to the circumferentially inward portion of the inward-facing connecting portion or the outward-facing connecting portion, and is inclined radially inward as it moves circumferentially inward, and its radial thickness is greater than the radial thickness of the side rib positioned radially inward of the missing portion. Of the multiple side ribs, the side rib positioned radially inward of the missing portion has its circumferentially outer end connected to the circumferentially outer end of the inward-facing connecting portion or the outward-facing connecting portion, and is inclined radially outward as it moves circumferentially inward. Caliper for opposed-piston disc brakes.

2. The opposing piston type disc brake caliper according to claim 1, wherein, when viewed from the radially outer side, the side rib located radially inward of the missing material portion protrudes outward from the side rib located radially outward of the missing material portion.

3. The reinforcing rib has a flat design surface on its circumferential inner portion, which is formed by the axial outer surface of the reinforcing rib. The design surface and the axial outer surface of the side rib are smoothly connected without any steps. A caliper for opposed-piston type disc brakes as described in claim 1.

4. The opposing piston type disc brake caliper according to claim 1, wherein the axial outer surface of each of the side ribs is inclined in a direction that increases from the circumferential outer side toward the axial inner side.

5. The opposing piston type disc brake caliper according to claim 1, wherein at least one of the side ribs has an internal passage for passing brake fluid.

6. The aforementioned material-reducing portions are provided one each in the radially intermediate portion of the circumferential outer portions of the reinforcing rib, Each of the aforementioned missing portions has a roughly triangular shape when viewed axially, and its radial width increases towards the outer circumferential direction. Of the reinforcing ribs, the portion excluding the material-deficient portion has a roughly X-shape when viewed in the axial direction. A caliper for opposed-piston type disc brakes as described in claim 1.

7. The opposing piston type disc brake caliper according to claim 6, wherein the axial thickness of the portion of the reinforcing rib excluding the material-deficient portion is greater in the portion that extends circumferentially outward from the outer cylinder portion than in the portion that covers the bottom of the outer cylinder portion.

8. The aforementioned material-depleted portion is bottomed, as described in claim 1, for a caliper for an opposed piston type disc brake.

9. The aforementioned material-reduced portion is bottomless, as described in claim 1, for a caliper for an opposed-piston type disc brake.

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