JPH08177895A - Disk brake - Google Patents

Abstract

PURPOSE: To surely prevent generation of tilt on a cylinder head at the time of no-brake. CONSTITUTION: A pair of brake pads 3, 4 are arranged opposing in a face to face in condition in which a disk rotor 1 is held. The brake pads 3, 4 are slidably supported to a torque member 2. Shaft parts of slide pins 14, 15 are inserted in a pair of sliding holes 16a, 17a which are arranged on the torque member 2. A pair of slide pins 14, 15 are fixed to a cylinder body 9. Dust protective boots 18, 19 are interposed between respective slide pins 14, 15 and the sliding holes 16a, 17a. Each elastic ratio of a pair of boots 18, 19 is uniformalized, and the boots 18, 19 are set so as to make the length (a natural length) at the time of no-load differ.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake in which a cylinder body for pressing a pair of brake pads against a disc rotor is slidably supported by a torque member via slide pins. .

[0002]

2. Description of the Related Art As a conventional disc brake, for example, there is one described in Japanese Patent Laid-Open No. 1-176822. As shown in FIG. 22, the disc brake has a structure in which a pair of brake pads 51 are arranged to face each other with the disc rotor 50 interposed therebetween and the torque member 5 is disposed.
2 is slidably supported. The torque member 52 is provided with a pair of cylinder body holding members 53 extending in the axial direction of the disc rotor 50. The slide pins 54 are slidably inserted into the slide holes of the cylinder body holding members 53 extending in the axial direction of the disc rotor 50. The pair of slide pins 5
4 is fixed to the cylinder body 56 via the arm 55. In the conventional example, the slide pin 54 is provided between the head side of the slide pin 54 and the opening position of the slide hole.
A dustproof boot 59 for protecting the shaft portion of the is installed.

Further, the cylinder body 56 is arranged so as to straddle the disc rotor 50, and the claw portion 56a at the tip end thereof faces the outer surface of one brake pad 51, and the base portion of the cylinder body 56. The piston 58 arranged in the cylinder hole 57 on the side can come into contact with the other brake pad 51. The sliding holes of the pair of cylinder body holding members 53 have the same hole diameter, and one slide pin is used to prevent rattling of the cylinder body 56 due to the clearance between the sliding hole and the slide pin 54. By setting the shaft diameter of the (main pin) large, the clearance on the side of the main pin is set small. In the non-braking state, the cylinder body 56 is supported by the torque member 52 on the main pin side.

Further, in the above disc brake, the cylinder body 5 is slid in the sliding direction of the cylinder body 56.
The position of the center of gravity of 6 is set so as to be located within the sliding portion area between the slide pin 54 and the sliding hole. That is,
The position of the center of gravity of the cylinder body 56 is set between the contact portion between the opening end of the sliding hole and the shaft portion of the slide pin 54 and the contact portion between the sliding hole and the tip of the slide pin 54. As described above, the slide pin 54 and the cylinder body holding member 53 extend in the axial direction. This prevents the cylinder body 56 from tilting during non-braking.

[0005]

However, even in the disc brake having the above structure, the position of the center of gravity of the cylinder body 56 slides between the slide pin 54 and the sliding hole due to wear of the brake pad or the like. If it is located outside the moving sub-region, the cylinder body 56 may still tilt.

In the above conventional disc brake,
A dustproof boot 59 is provided to protect the shaft portion of the slide pin 54 protruding from the opening of the sliding hole from water, dust, and the like. The abrasion causes a sliding displacement in the axial direction to change the length protected by the dustproof boot 54. Therefore, as the dustproof boot 54, an elastic body made of a bellows-shaped rubber body or the like that can expand and contract in the axial direction of the slide pin may be used.

However, when the dustproof boot 54 is made of the above elastic body, the dustproof boot has a predetermined elastic force due to the change in the length thereof. Since this elastic force acts on the cylinder body 56 as a rotation moment, even if the position of the center of gravity of the cylinder body 56 is located within the sliding contact area between the main pin and the sliding hole,
There is a problem that the posture of the cylinder body 56 with respect to the torque member 52 may tilt.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a disc brake in which the cylinder body is surely prevented from tilting during non-braking.

[0009]

In order to achieve the above-mentioned object, the invention described in claim 1 of the present invention is a pair of brakes which are arranged to face each other substantially in parallel with a friction surface of a disk rotor rotating together with a wheel. A pad, a torque member fixed to the vehicle body side for receiving a braking torque from the brake pad, a cylinder body provided with a piston that is disposed across the disc rotor and can press the brake pad toward the disc rotor, and the cylinder A slide pin fixed to one of the body and the torque member and extending in the axial direction of the disc rotor, and a slide hole provided in the other of the cylinder body and the torque member to support the slide pin so as to be slidable only in the axial direction, respectively. A cylinder body holding member having a Cylinder body rotation supporting means for generating a biasing force capable of canceling a rotation moment generated in the cylinder body due to the displacement between the center of gravity of the inner body and the sliding contact position of the slide pin and the cylinder body holding member is provided. Is characterized by.

The invention described in claim 2 is different from the structure described in claim 1 in that it is interposed between the slide pin and the cylinder body holding member and is predetermined in the axial direction of the slide pin. Along with the dustproof boot that is elastically expandable and contractible, the cylinder body rotation supporting means is
The rotation moment generated in the cylinder body due to the deviation between the position of the center of gravity of the cylinder body and the position of the sliding contact end of the slide pin and the cylinder body holding member, and the position of the sliding contact end due to the elastic force of the dustproof boot are fulcrums. Is generated to generate a biasing force capable of canceling out the rotational moment generated in the cylinder body.

Further, the invention described in claim 3 is characterized in that, in addition to the configuration described in claim 1 or 2, the cylinder body rotation supporting means is made of an elastic body. Further, according to the invention described in claim 4, in addition to the configuration described in any one of claims 1 to 3, the cylinder body rotation supporting means is interposed between the slide pin and the cylinder body holding member. It is characterized by wearing.

Further, in the invention described in claim 5, in addition to the structure described in claim 3 or 4, the cylinder body rotation supporting means is interposed between the slide pin and the cylinder body holding member. It is characterized in that it is equipped with a dustproof boot. The invention described in claim 6 is different from the configuration described in claim 5 in that a pair of slide pins and a cylinder body holding member are provided, and the dustproof boot is provided between each slide pin and the cylinder body holding member. It is characterized in that the two dustproof boots have different elastic moduli while being interposed.

The invention described in claim 7 is different from the structure described in claim 5 in that a pair of slide pins and a cylinder body holding member are provided, and the above-mentioned structure is provided between each slide pin and the cylinder body holding member. The dustproof boots are interposed, and the initial strain amounts of the two dustproof boots in the sliding direction of the cylinder body when not braking are different.

Further, the invention described in claim 8 is different from the structure described in claim 5, in that a pair of slide pins and a cylinder body holding member are provided, and the above-mentioned structure is provided between each slide pin and the cylinder body holding member. It is characterized in that the dustproof boots are interposed and the lengths of the two dustproof boots at the time of no load are different. In addition, the invention described in claim 9 is different from the configuration described in claim 7 or 8 in that
At least one mounting position of each of the two dustproof boots on each slide pin or the cylinder body holding member is offset in the cylinder body sliding direction.

Further, the invention described in claim 10 is different from the structure described in any one of claims 8 to 9 in that at least the end of the dustproof boot and the slide pin or the cylinder body holding member are provided. It is characterized in that a spacer is interposed between the one side and the other side. Further, the invention described in claim 11 is different from the configuration described in any one of claims 1 to 10 in that it is provided with a pair of slide pins and a cylinder body holding member, and the cylinder body rotation supporting means is provided. , At least one of the pair of slide pin arrangement positions.

In addition, in the invention described in claim 12, in addition to the structure described in any one of claims 1 to 11, the cylinder body rotation supporting means changes the rotation by changing the movement of the cylinder body. It is characterized in that it comprises a canceling means capable of canceling the change in the moment value. Further, in the invention described in claim 13, in addition to the structure described in claim 12, the cylinder body rotation supporting means is composed of an elastic body, and the canceling means includes the sliding amount of the cylinder body and the elasticity. It is characterized in that it is configured such that the amount of strain of the body is interlocked and that it has an elastic modulus capable of canceling the change of the rotational moment by the change of the amount of strain of the elastic body.

Further, the invention described in claim 14 is different from the structure described in any one of claims 1 to 13 in that the slide pin and the cylinder body holding member are arranged in the sliding direction of the cylinder body. It is characterized in that the center of gravity of the cylinder body is set in the sliding area. Further, the invention described in claim 15 is
In addition to the configuration according to any one of claims 1 to 14, a pair of slide pins and a cylinder body holding member are provided, and the diameters of the sliding holes of the pair of cylinder body holding members are different from each other. The slide pins have the same diameter.

[0018]

According to the invention described in claim 1, the rotational moment generated on the cylinder body due to the weight of the cylinder body itself with the slide contact end position between the slide pin and the cylinder body holding member as a fulcrum is a cylinder body rotation support. It is canceled by the urging force of the means. Therefore, the cylinder body is prevented from tilting during non-braking.

According to the second aspect of the invention, the rotational moment generated by the weight of the cylinder body itself as well as the rotational moment generated by the elastic force of the dustproof boot with the sliding contact end position as the fulcrum are also measured. It is canceled by the urging force of the body rotation support means. Therefore, even if the dustproof boot has a predetermined elastic force and the elastic force adversely affects the tilting of the cylinder body, the cylinder body does not tilt during non-braking.

According to the third aspect of the present invention, the cylinder body rotation supporting means is made of an elastic body, so that the urging force of the cylinder body rotation supporting means can be changed in accordance with the movement of the cylinder body. At this time, as the position of the center of gravity of the cylinder body changes as the cylinder body moves, the rotational moment input to the cylinder body changes. Therefore, in the invention described in claim 3,
The urging force of the cylinder body rotation supporting means can be changed according to the change of the rotation moment.

Further, in the invention described in claim 4, the cylinder body rotation supporting means is interposed between the slide pin and the cylinder body holding member, so that a displacement amount equivalent to the movement of the cylinder body is obtained. Can be input to. Further, in the invention described in claim 5, since the dustproof boot is provided with the cylinder body rotation supporting means, it is not necessary to provide the cylinder body rotation supporting means as a separate member. In addition, by positively providing the dustproof boot with elastic force, the cylinder body is prevented from tilting due to the displacement of the position of the center of gravity of the cylinder body, and at the same time, the dustproof boot has a negative effect on the tilting of the cylinder body. It can be prevented.

Further, in the invention described in claim 6, by making the elastic forces of the two dustproof boots different from each other, it is possible to generate by both dustproof boots as compared with the conventional case where the elastic forces of both dustproof boots are equal. The range of selection of each elastic force is widened, and by appropriately selecting the elastic force of each dustproof boot, it becomes possible to cancel the rotational moment generated in the cylinder body.

Further, in the invention described in claim 7, by making the elastic moduli of the two dustproof boots different, it is possible to generate by the both dustproof boots as compared with the conventional case where the elastic moduli of both dustproof boots are equal. The range of selection of each elastic force is widened, and by appropriately selecting the elastic modulus of each dustproof boot, the rotational moment generated by each elastic force of both dustproof boots can cancel the rotational moment generated in the cylinder body. It will be possible.

Further, in the invention described in claim 8, since the two dustproof boots constituting the cylinder body rotation supporting means have different initial strains, the two conventional dustproof boots have the same initial strains. Compared with this, the range of selection of each elastic force that can be generated by both dustproof boots is widened, and by appropriately selecting the initial strain amount of each dustproof boot, the rotation moment generated by each elastic force of both dustproof boots causes the cylinder It becomes possible to cancel the rotational moment generated in the body.

Further, in the invention described in claim 9, since the two dustproof boots have different unloaded lengths, the two dustproof boots have the same unloaded length as compared with the conventional case. The range of selection of each elastic force by the two dustproof boots is widened, and by appropriately selecting the length of each dustproof boot when there is no load, the cylinder body is generated by the rotation moment generated by each elastic force of both dustproof boots. It is possible to cancel the rotational moment generated in the.

According to the tenth aspect of the invention, since the mounting positions of at least one of the slide pins or the cylinder body holding member of the two dustproof boots are offset in the cylinder body sliding direction, both dustproof boots are provided. The distance between the attachment points on each end of the boot is different. As a result, the amount of initial strain and the like of the two assembled dustproof boots differ.

Further, in the invention as set forth in claim 11, by interposing the spacer, the distance between the attachment points of both ends of the dustproof boot changes according to the thickness of the spacer, and the initial strain amount of the dustproof boot is changed. Is changed. Further, according to the invention described in claim 12, by providing the cylinder body rotation supporting means at the slide pin arrangement position, the cylinder body rotation supporting means can be arranged integrally with or in the vicinity of the dustproof boot, and the elastic force of the dustproof boot. It is possible to effectively cancel the rotation moment due to. Further, when the dustproof boot is provided with the cylinder body rotation supporting means, even if there is a pair of dustproof boots, only one of the dustproof boots can be provided with the cylinder body rotation supporting means.

Further, in the invention described in claim 13, since the offsetting means offsets the fluctuation of the rotational moment due to the displacement of the position of the cylinder body during non-braking, the position of the cylinder body during non-braking is displaced. However, the tilting of the cylinder body is reliably prevented. Further, in the invention described in claim 14, the strain amount of the elastic body provided with the cylinder body rotation supporting means changes in accordance with the movement of the cylinder body, and the change amount of the elastic force of the elastic body due to the change causes the cylinder body to change. The change amount of the rotation moment due to the change of the position is offset.

According to the fifteenth aspect of the invention, even when the slide pins having the same diameter are used as the pair of slide pins, the diameters of the slide holes are made different so that the slide pins are separated from each other. The clearances can be different, and one of the slide pins can be set as the main pin. That is, by setting the diameter of one of the sliding holes to be relatively small, rattling on the main pin side can be prevented.

[0030]

An embodiment of the present invention will be described with reference to the drawings.
1 to 4 are diagrams for explaining the first embodiment.
FIG. 1 is a plan view showing the overall structure of the disc brake of this embodiment, FIGS. 2 and 3 are sectional views showing the respective dustproof boots, and FIG. 4 is a diagram showing the setting of the elastic force of each dustproof boot. It is a figure for explaining a value etc. Here, the rotor entry side in the following description is the side indicated by C in FIG. 1 and the side where the disc rotor 1 enters the disc brake, and the rotor entry side is 1 is the side indicated by D in FIG. 1 and the side where the disc rotor 1 exits from within the disc brake.

First, the structure will be described. As shown in FIG. 1, a disk rotor 1 which is rotatable integrally with a wheel and a torque member 2 which is fixed to a vehicle body side member such as an axle and receives a torque are provided. The torque member 2
A pair of brake pads 3 and 4 are slidably supported with the disc rotor 1 sandwiched therebetween. The torque member 2 has a pair of cylinder body holding members 1 extending in parallel to the axial direction of the disc rotor 1 from a position on the rotor turn-in side C and a position on the turn-out side D thereof.
6, 17 are provided. Each of the cylinder body holding members 16 and 17 has an opening at one end surface, and the disk rotor 1
Are provided with sliding holes 16a and 17a extending in the axial direction, and the shaft portions of the slide pins 14 and 15 are slidably inserted into the sliding holes 16a and 17a, respectively. The heads 12, 13 of the pair of slide pins 14, 15 have arms 10, 1 extending parallel to the friction surface of the disk rotor 1.
It is fixed to the cylinder body 9 via 1. Of the pair of slide pins 14 and 15, the slide pin 14 physically on the upper side has a relatively large diameter and constitutes a main pin, and the lower slide pin 15 constitutes a sub pin.

Here, in the axial direction of the disc rotor 1, the position of the center of gravity of the cylinder body 9 is set so as to be located within the sliding area between the slide pins 14 and 15 and the sliding holes 16a and 17a. . That is, the sliding holes 16a, 1
Between the contact portion between the opening end of 7a and the shaft portion of the slide pins 14 and 15, and the contact portion between the inner peripheral surfaces of the slide holes 16a and 17a and the tip portions of the slide pins 14 and 15. , The slide pins 14 and 15 and the cylinder body holding members 16 and 17 so that the position of the center of gravity of the cylinder body 9 is set.
Are extended in the axial direction. This prevents tilting of the cylinder body 9 in the unloaded state.

Further, the cylinder body 9 is arranged so as to straddle the disk rotor 1 in the axial direction, and the claw portion 9a at the tip of the cylinder body 9 has one brake pad 4 (outer
The outer surface of the pad) can be opposed to and abutted. On the base side of the cylinder body 9, a cylinder hole 21 is formed with the opening facing the outer surface of the other brake pad 3 (inner pad), and the piston 7 is arranged in the cylinder hole 21. ing. The piston 7 is regulated by the cylinder hole 21, and can be stroked toward the friction surface of the disc rotor 1 according to the hydraulic oil supplied to and discharged from the cylinder through the pipe 23.

Further, between the mounting portions of the slide pins 14 and 15 on the head portions 12 and 13 and the positions of the opening portions of the slide holes 16a and 17a, the slide pins protruding from the slide holes 16a and 17a. Dustproof boots 18 and 19 are interposed so as to cover the shaft portions of 14 and 15. The dustproof boot 1
8 and 19 are formed of a rubber body in a bellows shape, and can extend and contract with a predetermined elastic force in the sliding direction of the slide pins 14 and 15. The dustproof boots 18 and 19 also serve as a cylinder body rotation supporting means and a canceling means.

The pair of dustproof boots 18 and 19 are
2 and 3, the elastic modulus in the expansion / contraction direction is the same, but the length without load (natural length) S
1 and S2 are set to be different. That is, both the dustproof boots 18 and 19 are made of the same material, but unlike the conventional ones, their natural lengths S1 and S2 are intentionally different.

At this time, the distance between the mounting portions of the slide pins 14 and 15 on the head portions 12 and 13 and the positions of the opening portions of the sliding holes 16a and 17a, to which both ends of the dustproof boots 18 and 19 are attached, are both set. Since they are the same, the expansion and contraction amounts (distortion amounts) of the dustproof boots 18 and 19 at the time of non-braking are different.
As a result, the initial elastic forces of the dustproof boots 18 and 19 are different from each other, and the initial elastic force cancels the rotational moment generated in the cylinder body 9 due to the displacement of the position of the center of gravity of the cylinder body 9. The initial expansion / contraction amount and elastic modulus of 18 and 19 are set.

Next, the elastic force as the biasing force generated by the initial expansion and contraction amount set in each of the dustproof boots 18, 19 and the value of each elastic modulus for constructing the canceling means will be described with reference to FIG. Explain. Here, the initial elastic forces set in the dustproof boots 18 and 19 and directed in the axial direction are F1 and F2, respectively. Further, in the following description, the contact position between the tip of the slide pin 14 forming the main pin and the sliding hole 16a is called point A, and the slide pin 14 forming the main pin and the opening end of the sliding hole 16a are called. The contact position with the section is called point B. The points A and B are the sliding contact end positions in this embodiment.

First, the elastic forces F1 and F2 of the dustproof boots set as the urging forces on the dustproof boots 18 and 19 will be described. As shown in FIG. 4, the disc brake of this embodiment has a configuration in which the slide pin 14 that constitutes the main pin is arranged on the upper side (the upper side in the direction of gravity). The cylinder body 9 is supported by the torque member 2 by the side of the slide pin 14 that forms the main pin, and the side of the slide pin 15 that forms the lower sub pin is in a floating state.

Considering the rotation moment with the point A as the fulcrum, the rotation moment M1 as shown in the following formula (1) acts on the point A from FIG. In the following description, for the sake of simplicity, the pair of slide pins 14 and 15
The shaft diameters of are described as being equal. M1 = L1.mg + (h / 2) .F1- (2.L3- (h / 2)). F2 (1) where L1: fulcrum A and cylinder body of cylinder body sliding direction Deviation from the center of gravity position G L2: Deviation between the fulcrum B and the position of the center of gravity G of the cylinder body in the cylinder body sliding direction L3: Up to the position of the cylinder body center of gravity G from both slide pins in the direction of rotation of the disk rotor Distance: mg: Weight of cylinder body h: Diameter of slide pin shaft F1: Elastic force by dustproof boot on slide pin side that composes main pin F2: Represents elastic force by dustproof boot on slide pin side that composes sub pin There is.

When M1 becomes M1 <0, the cylinder body 9 tilts counterclockwise in the figure. On the other hand, B
Considering the rotation moment with the point as the fulcrum, the following (2)
A moment M2 around the point B as shown by the formula is generated in the cylinder body 9. M2 = -L2 * mg + (h / 2) * F1- (2 * L3- (h / 2)) * F2 (2) Then, when this M2 becomes M2> 0, the cylinder body 9 becomes It tilts around the middle clock.

From the above, it can be seen that in order to prevent the cylinder body 9 from tilting, it is sufficient to satisfy the conditions of M1 ≧ 0 and M2 ≦ 0. That is, L1 · mg ≧ (2 · L3- (h / 2)) · F2- (h / 2) · F1 (3) and −L2 · mg ≦ (2 · L3- (h / 2) ) .F2- (h / 2) .F1 (4).

Therefore, based on the above equations (3) and (4),
By setting the initial expansion and contraction amounts of the dustproof boots 18 and 19 so that the values F1 and F2 satisfy the following expression (5), the cylinder body 9 is displaced due to the position G of the center of gravity of the cylinders 9 It can be seen that the rotational moment generated in the body 9 is canceled and the tilting of the cylinder body 9 during non-braking can be prevented.

-L2 · mg ≦ (2 · L3- (h / 2)) · F2- (h / 2) · F1 ≦ L1 · mg (5) And the above L1, L2, L3, h, Since each mg is a predetermined value, based on the above formula, "(2.L3- (h
/ 2)) · F2- (h / 2) · F1 ”can be selected, and the initial elastic forces F1 and F2 to be applied to the dustproof boots 18 and 19 are selected from the obtained values.

For example, the initial elastic force F1 of the dustproof boot 18 on the slide pin 14 side constituting the main pin is zero,
That is, when the initial expansion / contraction amount is set to zero, the initial elastic force F2 on the slide pin 15 side that constitutes the sub pin is selected from the above formula (5) so as to satisfy the following formula (6). -L2 · mg / (2 · L3) ≦ F2 ≦ L1 · mg / (2 · L3) (6) In the above formula (6), compared with L3, (h / 2)
Is negligible, so (h / 2) is ignored.

In the present embodiment, since the natural lengths S1 and S2 of both dustproof boots 18 and 19 at the time of no load are different, only the dustproof boot 19 on the slide pin side which constitutes the sub pin satisfies the above formula (6). The amount of expansion and contraction of each of the dustproof boots 18 and 19 can be set so as to obtain the elastic force F2. Next, the elastic moduli k1 and k2, which are set in the dustproof boots 18 and 19 and constitute a canceling means, that is, a means for canceling a change in the rotational moment value that changes due to the sliding of the cylinder body 9, will be described.

Considering now the condition that the outer brake pad 4 is worn by Δx, the cylinder body 9 is slidably displaced to the inner brake pad 3 side (right side in FIG. 4) by the wear amount Δx. At this time, since the point A is integrated with the cylinder body 9, the point A is displaced toward the inner brake pad 3 side by the same amount, and the relationship between the point A and the position of the center of gravity of the cylinder body 9, that is, L1 does not change. . But B
Since the point is located at the opening end of the sliding hole 16a, it relatively approaches the center of gravity point position G of the cylinder body 9 by Δx.

Further, due to the displacement Δx, the respective dustproof boots 18 and 19 are contracted by that amount, so that both dustproof boots 18 and 1 are
The elastic forces F1 and F2 caused by 9 are F1 ′ and F2 ′, respectively.
Changes to At this time, the condition that the cylinder body 9 does not rotate due to the rotation moment when the point A becomes the fulcrum when not braking is the following formula (7) based on the above formula (1). L1 · mg + (h / 2) · F1 ′ − (2 · L3- (h / 2)) · F2 ′ ≧ 0 (7) Here, the elastic moduli set for the dustproof boots 18 and 19 are respectively set. Assuming k1 and k2, the elastic forces F1 'and F2' generated in the dustproof boot are expressed by the following equations.

F1 ′ = F1 + k1 · Δx (8) F2 ′ = F2 + k2 · Δx (9) Substituting this into the above equation (7) and transforming, L1 · mg + (h / 2) · F1- (2 ・ L3- (h /
2)) · F2 + Δx · {k1 · (h / 2) −k2 · (2
・ L3− (h / 2))} ≧ 0, and k2 · (2 · L3− (h / 2)) − k1 · (h / 2) ≦ (1 / Δx) · {L1 · mg + (h / 2 ) .F1- (2.L3- (h / 2)). F2} ... (10).

On the other hand, the condition that the cylinder body 9 does not rotate around the point B as a fulcrum when it is worn by Δx is that the following formula is satisfied based on the formula (2). -L2 '・ mg + (h / 2) ・ F1'-(2 ・ L3-
(H / 2)) · F2 ′ ≦ 0 By substituting the equations (8) and (9) into this equation and transforming it, −L2 · mg + (h / 2) · F1- (2 · L3- (H /
2)) ・ F2 + Δx ・ {mg + k1 ・ (h / 2) -k2
· (2 · L3- (h / 2))} ≦ 0, and k2 · (2 · L3- (h / 2)) − k1 · (h / 2) ≦ mg + (1 / Δx) · {−L2 · mg + (h / 2) .F1- (2.L3- (h / 2)). F2} (11).

Therefore, even if the brake pads 3 and 4 wear, in order to cancel the change in the rotational moment generated in the cylinder body 9 and prevent the cylinder body 9 from tilting, from the above equations (10) and (11), It is understood that the elastic moduli k1 and k2 may be set so as to satisfy the following expression (12). mg + (1 / Δx) * {-L2 * mg + (h / 2) * F1- (2 * L3- (h / 2)) * F2} <(2 * L3- (h / 2)) * k2-k1 · (H / 2) ≦ (1 / Δx) · {L1 · mg + (h / 2) · F1− (2 · L3- (h / 2)) · F2} (12) As Δx above Is calculated by the maximum wear amount allowed for the brake pad.

Here, in this embodiment, both dustproof boots 1 are used.
Since the elastic moduli k1 and k2 of 8 and 19 are equal,
3) Set the value to satisfy the equation. (Mg / 2 · L3)-(L2 · mg / 2 · Δx · L3)-(F2 / Δx) ≦ k1, k2 ≦ (L1 · mg / 2 · Δx · L3)-(F2 / Δx) ... (13) Since (h / 2) is much smaller than L3,
(H / 2) and F1 · (h / 2) are calculated as negligible.

By setting the elastic moduli k1 and k2 of the dustproof boots 18 and 19 and the initial expansion and contraction amounts, that is, the elastic forces F1 and F2 based on the above equations, the dustproof boots 18 and 19 are set. Includes a cylinder body rotation support means and a canceling means. Next, the operation and the like of the above configuration will be described. When the brake pads 3 and 4 are not worn and in a non-braking state, the position of the center of gravity of the cylinder body 9 and the sliding contact end positions of the slide pin 12 and the cylinder body holding member 16 are displaced in the cylinder body sliding direction. The rotational moment generated in the cylinder body 9 is canceled by the initial elastic forces F1 and F2 of the dustproof boots 18 and 19 set as described above. Therefore, the cylinder body 9 does not tilt during non-braking.

Further, even if the position of the cylinder body 9 moves due to wear of the brake pads 3 and 4 and the rotational moment input to the cylinder body 9 changes, the wear of the brake pads 3 and 4 is followed. The dustproof boots 18,1
The expansion and contraction amount of 9 changes, and the dustproof boots 18, 1 due to the expansion and contraction
The change in the elastic force of 9 cancels out the amount of change in the rotational moment, thereby preventing the cylinder body 9 from tilting.

This prevents the cylinder body 9 from falling. Therefore, the brake pads 3 and 4 do not receive the force from the cylinder body 9, and
It does not increase the sliding resistance of the cylinder body 9. Therefore, it is possible to reduce the contact of the brake pads 3 and 4 with the disc rotor 1 during non-braking, reduce wear of the disc rotor 1 and the brake pads 3 and 4, especially uneven wear, and extend the life.

Further, the brake judder phenomenon caused by the variation in the thickness of the disc rotor 1 can be suppressed. That is, during braking, the fluctuation of the braking torque is suppressed, so that even if the brake pads 3 and 4 are worn, it is possible to obtain a stable braking torque, and at the same time, the discomfort transmitted to the occupant via the vehicle body and the hydraulic system is increased. Vibration can be reduced. In the above embodiment, the natural length S1 of both dustproof boots 18 and 19 when there is no load,
By changing S2, the initial elastic force of both dustproof boots 18, 19 is made different, that is, the amount of initial expansion and contraction is made different so as to also serve as the cylinder body rotation support means. The means for varying the amount is not limited to this.

For example, as shown in FIGS. 5 to 7, the positions 24a of the dustproof boot mounting portions provided on the head side of the shaft portions 24 and 25 of the pair of slide pins 14 and 15,
By making 25a different in the sliding direction of the cylinder body 9, the distance between the both ends of the dustproof boots 18, 19 is made different, and the initial expansion / contraction amount (distortion amount) of both dustproof boots 18, 19 is changed. You may make it different. In this case, as the dustproof boots 18 and 19, the same members having the same natural length can be adopted as in the conventional case.

Alternatively, as shown in FIGS. 8 and 9, by axially offsetting the dustproof boot mounting portions 16b and 17b of the cylinder body holding members 16 and 17, the initial expansion and contraction of both dustproof boots 18 and 19 can be performed. Amount (distortion amount)
May be different. Also in this case, as the dustproof boots 18 and 19, the same members having the same natural length can be adopted as in the conventional case.

Alternatively, as shown in FIG. 10, the ring-shaped spacer 26 as shown in FIG. 11 is inserted into the mounting portion on the one arm 10 side of the cylinder body 9 so that one of the dustproof boots can be mounted. The mounting portion of the cylinder body 18 on the cylinder body side may be brought close to the sliding hole 16a so that the initial expansion and contraction amounts of the dustproof boots 18 and 19 are different. Also in this case, the same members having the same natural length can be adopted as the dustproof boots 18 and 19.

Alternatively, as shown in FIGS. 12 and 13,
Arms 10 and 11 extending from the cylinder body 9 to the left and right
By offsetting S3 in the sliding direction of the cylinder body 9 so as to make the distance between both ends of the dustproof boots 18 and 19 different so that the initial expansion and contraction amounts of the dustproof boots 18 and 19 are made different. May be. Also in this case,
As the dustproof boots 18 and 19, the same members having the same natural length can be adopted.

Further, in the above embodiment, both dustproof boots 1
Although it has been described that the elastic moduli 8 and 19 have the same elastic modulus, the elastic moduli of the dustproof boots 18 and 19 are made different by making the thicknesses of the dustproof boots 18 and 19 different so that Even if the dustproof boots 18 and 19 have the same natural length and the same initial expansion and contraction amount, both dustproof boots 18 and 1
The initial elastic force of 9 can be set to be different. In this case, the initial elastic force of the dustproof boots 18 and 19 is selected and set based on the equation (5), and the elastic modulus of the dustproof boots 18 and 19 is determined based on the equation (12). It is sufficient to select and set k1 and k2.

Next, the second embodiment will be described. The same members as those in the first embodiment will be designated by the same reference numerals for description. Here, FIG. 14 is a cross-sectional view of the dustproof boot. The basic structure of the second embodiment is the same as that of the first embodiment, but the structure of the cylinder body rotation supporting means is different. That is, in the first embodiment, the dustproof boots 18, 1
In the second embodiment, the cylinder body holding member 16,
In addition to the dustproof boots 14 and 15, a coil spring 27 as an elastic body that constitutes a cylinder body rotating means and a canceling means is interposed between the head 17 of the slide pin 14 and the slide pin 14 and 15.

That is, as the dustproof boots 18 and 19, the dustproof boots 18 and 19 having the same elastic modulus as the conventional ones and having the same natural lengths under no load are adopted. Then, as shown in FIG. 14, a coil spring 27 as an elastic body is disposed coaxially with the inner peripheral surfaces of the dustproof boots 18 and 19, and the cylinder spring is also provided by the coil spring 27 in addition to the dustproof boot. The body rotation supporting means and the offsetting means are configured.

Next, the initial values of the elastic force and elastic modulus set in the coil spring 27 to constitute the cylinder body rotation supporting means and the canceling means will be described. In the case of the second embodiment, the upper and lower slide pins 1
An elastic force, which is the sum of the elastic force of the dustproof boots 18 and 19 and the elastic force of the coil spring 27, is applied to the arrangement positions of 4 and 15.

If the elastic forces constituting the urging force of each coil spring 27 are FA1 and FA2 and the elastic forces of the dustproof boots 18 and 19 are F, the initial elastic force applied to each pin position is , Becomes the following formula. FB1 = F + FA1 (14) FB2 = F + FA2 (15) Therefore, in the equation (5) of the first embodiment, F1,
In order to be able to replace F2 with FB1 and FB2 and prevent the cylinder body 9 from tilting when not braking,
It is understood that the setting may be made so as to satisfy the following expression (16).

−L2 · mg ≦ (2 · L3- (h / 2)) · FB2- (h / 2) · FB1 ≦ L1 · mg (16) Furthermore, the above (14) is added to the equation (14). ) And (15)
By substituting the equations and transforming, the following equation (17) is obtained. By selecting the initial elastic forces FA1 and FA2 that satisfy this equation (17) as the elastic force of the coil spring 27, the cylinder body 9 during non-braking The tilting of is suppressed.
Therefore, in the second embodiment, the initial elastic forces FA1 and FA2 of the coil spring 27 are set based on the following equation (17).

-L2 · mg-2 · L3 · F ≦ 2 · L3 · FA2- (h / 2) · FA1 ≦ L1 · mg-2 · L3 · F (17) Here, compared to L3 Since h is small enough, (L3-
h3 is L3.

For example, when both dustproof boots 18 and 19 are set so as not to have elastic force during initial assembly,
It may be set based on the following equation (18). -L2 · mg ≦ 2 · L3 · FA2- (h / 2) · FA1 ≦ L1 · mg (18) Further, the initial elastic force FA1 of the coil spring 27 on the slide pin 14 side constituting the main pin is When it is set to zero, it may be set based on the following equation (19).

−L2 · mg / 2 · L3 ≦ FA2 ≦ L1 · mg / 2 · L3 (19) Further, each coil spring 2 for constituting the canceling means.
If the elastic moduli set to 7 are kA1 and kA2, and the elastic moduli of the dustproof boots 18 and 19 are k, the brake pad is
Force F generated at each pin position when worn by x
1'and F2 'are given by the following equations.

F1 ′ = (F + FA1) + Δx (k + kA1) F2 ′ = (F + FA2) + Δx (k + kA2) Therefore, the condition that the cylinder body 9 does not tilt even if the brake pad wears by Δx is based on the above formula (12). Is expressed by the following equation (20). mg + (1 / Δx) ・ {-L2 ・ mg + (h / 2) ・ (F + FA1)-(2 ・ L3- (h / 2)) ・ (F + FA2)} ≦ (2 ・ L3- (h / 2))・ (K + kA2)-(k + kA1) ・ (h / 2) ≦ (1 / Δx) ・ {L1 ・ mg + (h / 2) ・ (F + FA1)-(2 ・ L3- (h / 2)) ・ (F + FA2) } (20) For example, at the time of initial assembly, the elastic force F of the dustproof boots 18 and 19 is set to zero, and both coil springs 27
When the elastic forces of are set to be equal, they may be set based on the following equation (21). (Mg / 2 · L3) − (L2 · mg / 2 · Δx · L3) − (FA2 / Δx) ≦ k + kA1, k + kA2 ≦ (L1 · mg / 2 · Δx · L3) − (FA2 / Δx) ... (21) Since (h / 2) is much smaller than L3,
(H / 2) and F1 · (h / 2) are ignored.

By setting the elastic moduli kA1 and kA2 in accordance with the equation (21), tilting can be surely prevented. Next, the operation and the like of the above configuration will be described in detail. First, when the brake pads 3 and 4 are not worn and in a non-braking state, the position G of the center of gravity of the cylinder body 9, the slide pins 14 and 15, and the cylinder body holding member 1 are used.
The rotational moment generated in the cylinder body 9 due to the displacement of the sliding contact end positions of 6 and 17 in the cylinder body sliding direction and the rotational moment generated in the cylinder body 9 by the elastic force of the dustproof boots 18 and 19 are , Are canceled by the initial elastic force of the coil spring 27. Therefore, the cylinder body 9 does not tilt.

Further, the brake pads 3 and 4 are worn out,
Even if the rotational moment changes due to the displacement of the center of gravity of the cylinder body 9 or the elastic force due to the dustproof boots 18 and 19 changes, by setting the elastic moduli kA1 and kA2 of the coil spring 27 as described above, The expansion and contraction amount of the coil spring 27 changes in accordance with the wear of the brake pads 3 and 4 to offset the change in the rotational moment, and the tilting of the cylinder body 9 is prevented.

Further, in the second embodiment, the dustproof boot 1
Since the coil springs 27 constituting the cylinder body rotation supporting means and the offsetting means are provided separately from 8 and 19, the cylinder body rotation supporting means and the offsetting means are not affected by the deterioration of the dustproof boots 18 and 19 with time. The stable action of can be exhibited. Other actions and effects are the same as those of the first
It is similar to the embodiment.

As shown in FIG. 15, the spring 28 as the cylinder body rotation supporting means is provided inside the dustproof boots 18 and 19 with sliding holes 16a and 17a.
May be interposed between the opening end of the cylinder body and the mounting portion on the cylinder body 9 side facing the end. Alternatively, as shown in FIG. 16, a V-shaped spring as shown in FIGS. 17 and 18 is provided between the cylinder body holding members 16 and 17 and the arms 10 and 11 on the outer peripheral side of the dustproof boots 18 and 19. Member 2
9 and 30 may be installed to serve as a cylinder body rotation supporting means and a canceling means in addition to the dustproof boot.

Alternatively, a seal ring or the like is provided between the shaft portions of the slide pins 14 and 15 and the slide holes 16a and 17a to form a seal structure, and as shown in FIG. 15 lengths or a pair of sliding holes 16
The cylinder body rotation support means may be configured by making a and 17a different in depth. In this case, the slide holes 16a and 17a formed on the tip side of the slide pins 14 and 15 are formed.
The inner space 33 is an air spring, and the air spring constitutes a cylinder body rotation supporting means. And (1
The elastic force of each air spring is selected based on equation (7).

Next, the third embodiment will be described. The same members as those in the first embodiment will be designated by the same reference numerals for description. Here, FIG. 20 is a plan view for explaining the elastic force as the urging force of the cylinder body rotation supporting means and the elastic modulus as the offsetting means in the third embodiment. The basic structure of the third embodiment is similar to that of the first embodiment, and the dustproof boots 18 and 19 also serve as a cylinder body rotation supporting means and a canceling means. However, FIG.
As shown in FIG. 3, the only difference is that the slide pin 14 on the lower side is physically set to constitute the main pin. The other structure is similar to that of the first embodiment.

Next, each of the above dustproof boots 1 of the third embodiment.
The elastic force as the biasing force due to the initial expansion / contraction amount and the value of each elastic modulus set to 8 and 19 will be described with reference to FIG. Here, the initial elastic forces of the dustproof boots 18 and 19 toward the axial direction are F1 and F2 (the initial elastic force on the slide pin side that constitutes the main pin is F1).

As shown in FIG. 20, the disc brake of this embodiment has the slide pin 14 constituting the main pin on the lower side (lower side in the direction of gravity). Then, the cylinder body 9 is supported by the torque member 2 by the lower slide pin 14 side constituting the main pin, and the slide pin 15 side constituting the upper sub pin does not contribute to the support of the cylinder body 9. It is in a state of floating from the sliding hole 17a.

Therefore, in the non-braking state, the lower side of the shaft of the lower slide pin 14 and the lower side portion of the sliding hole 16a come into contact with each other, and the point A in FIG. A rotation moment acts on the cylinder body 9 with the point B as a fulcrum. Then, similar to the first embodiment, the initial expansion and contraction amounts of the respective dustproof boots 18 and 19 are given based on the rotation moments around the points A and B so that the values satisfy the following expressions. By doing so, tilting of the cylinder body during non-braking is prevented.

-L1 · mg ≦ (2 · L3 + (h / 2))
・ F2 + (h / 2) ・ F1 ≦ L2 ・ mg For example, when the initial elastic force F1 of the dustproof boot 18 on the slide pin 14 side that constitutes the main pin is set to zero, that is, when the initial expansion / contraction amount is set to zero. On the basis of the above equation, selects the initial elastic force F2 on the slide pin side that constitutes the sub pin so that the following equation is obtained.

-L1 · mg / (2 · L3) ≦ F2 ≦
L2 · mg / (2 · L3) Since (h / 2) is smaller than L3 in the above formula, (h / 2) is ignored. In this embodiment,
For example, the initial elastic force F2 that satisfies the above formula can be applied only to the dustproof boots 18 and 19 on the side of the slide pin 15 that constitutes the sub-pin, by making the natural lengths of both dustproof boots 18 and 19 different when no load is applied. Is.

Next, the elastic modulus set for both the dustproof boots 18 and 19 will be described. Here, each dust boot 1
The elastic moduli of 8 and 19 are k1 and k2, respectively. Even in the third embodiment, by considering the same as in the first embodiment, the following formula may be satisfied in order that the cylinder body 9 does not tilt even if the brake pads 3 and 4 wear. I understand.

-(1 / Δx) · {L1 · mg + (h /
2) ・ F1 + (2 ・ L3 + (h / 2)) ・ F2} ≦ k2
・ (2 ・ L3 + (h / 2)) + k1 ・ (h / 2) ≦ −m
g + (1 / Δx) ・ {L2 ・ mg- (h / 2) ・ F1-
(2 · L3 + (h / 2)) · F2} The Δx is calculated by the maximum wear amount allowed for the brake pads 3 and 4.

Here, for example, both dustproof boots 18, 19
When the elastic moduli of are equal, the values are set so as to satisfy the following formula. − (L1 · mg / 2 · Δx · L3) + (F2 / Δx) ≦
k1, k2 ≦-(mg / 2 · L3) + (L1 · mg / 2
.DELTA.x.L3)-(F2 / .DELTA.x) Since (h / 2) is much smaller than L3,
(H / 2) and F1 · (h / 2) are calculated as negligible.

By setting in this way, the dustproof boots 18 and 19 also serve as a cylinder body rotation supporting means and a canceling means. Next, the operation and the like of the above configuration will be described. The operation of the third embodiment is similar to that of the first embodiment,
When the brake pads 3 and 4 are not worn and in a non-braking state, the position of the center of gravity of the cylinder body 9 and the end position of the sliding contact portion between the slide pin and the cylinder body holding member are in the cylinder body sliding direction. The moment generated in the cylinder body due to the deviation is due to the initial elastic force F1, F which is the elastic force of the dustproof boots 18, 19.
Canceled by 2. Therefore, the cylinder body 9 is prevented from tilting.

Even if the brake pads 3 and 4 wear and the rotational moment input to the cylinder body 9 changes, the amount of expansion and contraction of the dustproof boots 18 and 19 also follows the wear of the brake pads 3 and 4. The change of the rotational moment is offset by the change of the elastic force of the dustproof boots 18, 19 due to the expansion and contraction, and the tilting of the cylinder body 9 is prevented.

Next, a fourth embodiment will be described. Fourth
In this embodiment, the same basic structure as that of the third embodiment is adopted, and the same structure as that of the second embodiment is adopted in each of the dustproof boots 18 and 19. Therefore, although not particularly shown,
In the following description, with reference to FIGS. 14 and 20, the same members as those in each of the above-described embodiments are designated by the same reference numerals.

The basic construction of the fourth embodiment has the same construction as that of the third embodiment, and the slide pin 14 constituting the main pin is set on the lower side. However, in addition to the dustproof boots 18 and 19, a coil spring 27 is interposed between the cylinder body holding members 16 and 17 and the heads of the slide pins 14 and 15. The coil spring 27 together with the dustproof boot constitutes the cylinder body rotation supporting means and the canceling means.

Next, the initial values of the elastic force and elastic modulus set in the coil spring 27 in order to configure the cylinder body rotation supporting means and the canceling means will be described. Like the third embodiment, the disc brake of the present embodiment has a configuration in which the slide pin 14 that constitutes the main pin is disposed on the lower side (lower side in the direction of gravity), so that in the non-braking state, The cylinder body 9 is supported by the torque member 2 by the side of the slide pin 14 that constitutes the main pin, and the side of the slide pin 15 that constitutes the upper sub-pin is
It does not contribute to the support of the cylinder body 9 and floats from the sliding hole 17a.

Therefore, in the non-braking state, the lower part of the shaft of the lower slide pin 14 and the lower part of the sliding hole 16a come into contact with each other, and point A in FIG. A rotation moment acts on the cylinder body 9 with the point B as a fulcrum. Then, similar to the second embodiment, based on the rotation moments about the points A and B, the initial expansion and contraction amounts of the respective dustproof boots 18 and 19 are given so that the values satisfy the following expressions. By doing so, tilting of the cylinder body during non-braking is prevented.

-L1 · mg-2 · L3 · F ≦ 2 · L3 ·
FA2 + (h / 2) ・ FA1 ≦ L2 ・ mg-2 ・ L3 ・
F Here, since h is sufficiently smaller than L3, (L3-
h3 is L3. For example, both dustproof boots 18,1
When 9 has no initial elastic force, it is set based on the following formula.

-L1 · mg ≦ 2 · L3 · FA2 + (h /
2) .FA1.ltoreq.L2.mg Further, when the initial elastic force FA1 of the coil spring 27 on the slide pin 14 side that constitutes the main pin is set to be zero, it is set based on the following formula. -L1 · mg / 2 · L3 ≦ FA2 ≦ L2 · mg / 2 · L3 Further, if the elastic moduli of the coil springs 27 constituting the canceling means are kA1 and kA2 and the elastic modulus of the dustproof boot is k, the fourth embodiment is performed. Even in the example, by considering the same as in the second embodiment, it can be understood that the following formula may be satisfied so that the cylinder body 9 does not tilt even if the brake pads 3 and 4 wear.

-(1 / Δx) · {L1 · mg + (h /
2) ・ (F + FA1) + (2 ・ L3 + (h / 2)) ・
(F + FA2)} ≦ (k + kA2) · (2 · L3 + (h
/ 2)) + (k + kA1) · (h / 2) ≦ −mg +
(1 / Δx) ・ {L2 ・ mg- (h / 2) ・ (F + FA
1) − (2 · L3 + (h / 2)) · (F + FA2)} The above Δx is calculated by the maximum wear amount allowed for the brake pad.

For example, the dustproof boot 1 at the time of initial assembly
When the initial elastic force F is not set in 8 and 19 and the elastic forces of both coil springs 27 are equal, it is set based on the following equation. (-L1 ・ mg / 2 ・ Δx ・ L3)-(FA2 / Δx)
≦ k + kA1, k + kA2 ≦ − (mg / 2 · L3) +
(L2 · mg / 2 · Δx · L3) − (FA2 / Δx) Since (h / 2) is much smaller than L3,
(H / 2) and F1 · (h / 2) are calculated as negligible.

With this setting, the coil spring 27 of the dustproof boot constitutes a cylinder body rotation supporting means and a canceling means. Next, the operation and the like of the above configuration will be described. The operation and the like of the fourth embodiment are similar to those of the second embodiment, and when the brake pads 3 and 4 are not worn and in the non-braking state, the position of the center of gravity of the cylinder body 9, the slide pin, and the cylinder body holding member. The rotational moment generated in the cylinder body due to the displacement of the sliding contact end position in the cylinder body sliding direction and the rotational moment generated in the cylinder body by the elastic force of the dustproof boot are both the initial elasticity of the coil spring 27. It has been canceled by force. Therefore, the cylinder body 9 is prevented from tilting.

Further, the brake pads 3 and 4 are worn,
Even if the rotational moment changes due to the displacement of the center of gravity of the cylinder body 9 or the elastic force due to the dustproof boots 18 and 19 changes, by setting the elastic moduli kA1 and kA2 of the coil spring 27 as described above, The expansion and contraction amount of the coil spring 27 also changes following the wear of the brake pads 3 and 4, and the rotational moment is offset by the change in the elastic force of the dustproof boots 18 and 19 due to the expansion and contraction.
The occurrence of tilting of the cylinder body 9 is prevented.

In all the above embodiments, the slide pin 1
Although an example in which the cylinders 4 and 15 are fixed to the cylinder body 9 side has been described, the slide pins 14 and 15 are fixed to the torque member 2 side and the cylinder body holding member 1
6 and 17 may be applied to the disc brake provided on the cylinder body 9 side. Further, in all of the above-described embodiments, the slide pins 14 constituting the main pin and the slide pin 15 constituting the sub-pin having different shaft diameters are used as in the conventional case, but the slide pins 14 and 15 have the same diameter. The same member is used, and the diameters of the sliding holes 16a and 17a of the cylinder body holding members 16 and 17 are made different so that the slide pin 14 serves as a slide pin constituting a main pin. You may have it. In this case, the same member can be commonly used as the pair of slide pins 14 and 15.

When the cylinder body rotation supporting means is provided at only one of the positions of both slide pins 14 and 15, it is preferable to provide it on the side of the slide pin 15 which constitutes the sub pin. Since the arm of the rotation moment with respect to the cylinder body 9 is much longer on the side of the slide pin 15 which constitutes the sub pin, the biasing force by the cylinder body rotation supporting means can be set small, which is advantageous.

Further, in all the above-described embodiments, the position G of the center of gravity of the cylinder body 9 is set in the sliding part area between the slide pins 14 and 15 and the slide holes 16a and 17a in the sliding direction of the cylinder body 9. However, the center of gravity of the cylinder body 9 may be located outside the sliding portion. However,
In this case, the range of selection of the elastic force and elastic modulus as the urging force of the cylinder body rotation supporting means is narrowed. For example,
Taking the expression (5) as an example, it can be seen that the value of L1 becomes a negative value and the width becomes narrow.

In the second and fourth embodiments, the disc brake provided with the dustproof boot is described as an example. However, the disc brake is dustproofed by grease instead of the dustproof boot. May be. In this case,
The initial elastic force and elastic modulus due to the dustproof boot in each formula of the above-mentioned embodiment may be regarded as zero. In the first and third embodiments, the dustproof boot is provided with the cylinder body rotation support means and the canceling means, and the initial elastic forces of the pair of dustproof boots are set to be different, but they are not necessarily the same. No need. However, when the initial elastic forces of the pair of dustproof boots are made to coincide with each other, the range of selection of the initial elastic forces becomes narrower, which is disadvantageous as compared with the case where the initial elastic forces are made different as in the above-described embodiment.

Further, in the above equations for obtaining the elastic modulus and the initial elastic force, the implicit condition is that the pair of slide pins are on the same vertical plane, but the pair of slide pins are on the same vertical plane. If it is not on the surface, the weight mg of the cylinder body is mg · cos θ according to the inclination angle θ.
Can be used instead of. Further, in the above embodiment,
Although an example in which the urging direction of the cylinder body rotation supporting means is set to the sliding direction of the cylinder body 9 has been described, the urging direction is not limited to this. For example, FIG.
As shown in FIG. 5, an elastic body as a cylinder body rotation supporting means that generates an elastic force F0 as a biasing force between the cylinder body 9 and the cylinder body holding member 17 in a direction oblique to the cylinder body sliding direction. 31 may be interposed.

In this case, assuming that the initial elastic force of the elastic body 31 is F0 and the arm length of the moment from the center of gravity position G of the cylinder body 9 to the elastic body 31 is L0, the elastic body is The rotational moment applied to the cylinder body 9 by 31 is M0 = F0 · L0. Therefore, it suffices to set M0 to a value that cancels the rotational moment generated in the cylinder body during non-braking.

For example, in the disc brake in which the slide pin constituting the main pin is arranged on the upper side as in the above-described first and second embodiments, by setting so as to satisfy the following equation, The tilting of the cylinder body during braking is prevented. M1 + M0 ≧ 0 and M2 + M0 ≦ 0 Therefore, −M1 ≦ M0 ≦ −M2

[0103]

As described above, in the disc brake of the present invention, the occurrence of tilting of the cylinder body during non-braking is avoided, so that even if the disc rotor has surface wobbling due to mounting errors or manufacturing errors, There is an effect that the partial wear of the disk rotor is reduced or eliminated, and the occurrence of brake judder can be suppressed.

Further, there is an effect that uneven wear of the brake pad is eliminated, stable braking torque is secured, and the brake pad has a long life and reduces the occurrence of abnormal noise such as squeal. In addition, the fall of the cylinder body is prevented, the brake pad does not receive the force from the cylinder body, and the sliding resistance of the cylinder body does not increase.

At this time, when any one of the structures described in claims 5 to 11 is adopted, the elasticity of the dustproof boot is positively provided without providing a separate member as the cylinder body rotation supporting means. Since the force is used, the tilting of the cylinder body due to the dustproof boot can also be suppressed. Further, claim 13 or claim 14
By adopting the above configuration, even if the position of the cylinder body moves during non-braking due to wear of the brake pad or the like, it is possible to reliably prevent the cylinder body from tilting.

Further, when the structure described in claim 15 is adopted, the same member can be further adopted as the pair of slide pins.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a disc brake of a first embodiment according to the present invention.

FIG. 2 is a sectional view showing the structure of one dustproof boot in the disc brake of the first embodiment according to the present invention.

FIG. 3 is a sectional view showing the structure of the other dustproof boot in the disc brake of the first embodiment according to the present invention.

FIG. 4 is a diagram for explaining the values of elastic force and elastic modulus of the first embodiment according to the present invention.

FIG. 5 is a diagram showing another example of the disc brake of the first embodiment according to the present invention.

FIG. 6 is a sectional view showing the structure of the shaft portion of one slide pin of the disc brake of the first embodiment according to the present invention.

FIG. 7 is a sectional view showing the structure of the shaft portion of the other slide pin of the disc brake of the first embodiment according to the present invention.

FIG. 8 is a diagram showing another example of the disc brake of the first embodiment according to the present invention.

FIG. 9 is a cross-sectional view showing the structure of a cylinder body holding member of the disc brake of the first embodiment according to the present invention.

FIG. 10 is a diagram showing another example of the disc brake of the first embodiment according to the present invention.

FIG. 11 is a perspective view showing a spacer of the disc brake according to the first embodiment of the present invention.

FIG. 12 is a diagram showing another example of the disc brake of the first embodiment according to the present invention.

FIG. 13 is a view of the cylinder body showing the position of the arm portion of the disc brake of the first embodiment according to the present invention.

FIG. 14 is a sectional view showing a state in which a spring as a cylinder body rotation supporting means is arranged in a dustproof boot of a disc brake according to a second embodiment of the present invention.

FIG. 15 is a diagram showing another example of the disc brake of the second embodiment according to the present invention.

FIG. 16 is a diagram showing another example of the disc brake of the second embodiment according to the present invention.

FIG. 17 is a view showing a structure of a spring as a cylinder body rotation supporting means arranged on one slide pin side of a disc brake of a second embodiment according to the present invention.

FIG. 18 is a view showing a structure of a spring as a cylinder body rotation supporting means arranged on the other slide pin side of the disc brake of the second embodiment according to the present invention.

FIG. 19 is a diagram showing another example of the disc brake of the second embodiment according to the present invention.

FIG. 20 is a diagram for explaining the occurrence of tilting of the cylinder body in the state in which the slide pin forming the main pin is arranged on the lower side in the third embodiment.

FIG. 21 is a view showing another embodiment of the disc brake according to the present invention.

FIG. 22 is a diagram showing a conventional disc brake.

[Explanation of symbols]

 1 Disc Rotor 2 Torque Member 3 Brake Pad (Inner Brake Pad) 4 Brake Pad (Outer Pad) 7 Piston 8 Seal Ring 9 Cylinder Body 10, 11 Arm 14 Slide Pin (Main Pin) 15 Slide Pin (Sub Pin) 16,17 Cylinder body holding member 18,19 Dustproof boot

Claims (15)

[Claims] 1. A brake pad, which is arranged to face a friction surface of a disk rotor that rotates together with a wheel so as to be substantially parallel to the friction surface, a torque member that is fixed to the vehicle body side and receives a braking torque from the brake pad, and straddles the disk rotor. A cylinder body provided with a piston capable of pressing the brake pad toward the disc rotor, a slide pin fixed to one of the cylinder body or the torque member and extending in the axial direction of the disc rotor, the cylinder body or the torque member. A cylinder body holding member provided on the other side of the cylinder body holding member that slidably supports the slide pins only in the axial direction, and a center point of the center of gravity of the cylinder body, Sliding contact part of slide pin and cylinder body holding member Disc brake, characterized in that provided cylinder body rotation supporting means for generating a biasing force that can cancel the rotational moment generated in the cylinder body by displacement with. 2. A dustproof boot which is interposed between the slide pin and a cylinder body holding member and is capable of expanding and contracting in the axial direction of the slide pin with a predetermined elastic force, and the cylinder body rotation supporting means is A rotational moment generated in the cylinder body due to a deviation between the position of the center of gravity of the cylinder body and the sliding contact end positions of the slide pin and the cylinder body holding member, and the sliding contact end position due to the elastic force of the dustproof boot are used as fulcrums. The disc brake according to claim 1, wherein the disc brake generates a biasing force capable of canceling a rotational moment generated in the cylinder body. 3. The disc brake according to claim 1, wherein the cylinder body rotation supporting means is made of an elastic body. 4. The disc brake according to claim 1, wherein the cylinder body rotation supporting means is interposed between the slide pin and the cylinder body holding member. 5. The disc brake according to claim 3, wherein the cylinder body rotation support means is provided in a dustproof boot interposed between the slide pin and the cylinder body holding member. 6. A pair of slide pins and a cylinder body holding member are provided, the dustproof boot is interposed between each slide pin and the cylinder body holding member, and the elastic forces of the two dustproof boots are different. Disc brake according to claim 5, characterized in that 7. A pair of slide pins and a cylinder body holding member are provided, the dustproof boot is interposed between each slide pin and the cylinder body holding member, and the elastic moduli of the two dustproof boots are different. Disc brake according to claim 5, characterized in that 8. A pair of slide pins and a cylinder body holding member are provided, said dustproof boot is interposed between each slide pin and the cylinder body holding member, and said two of said slide boots with respect to the cylinder body sliding direction during non-braking. The disc brake according to claim 5, wherein the dustproof boots have different initial strain amounts. 9. A pair of slide pins and a cylinder body holding member are provided, and the dustproof boot is interposed between each slide pin and the cylinder body holding member, and the length of the two dustproof boots when no load is applied. The disc brake according to claim 5, wherein the disc brake is different. 10. The method according to claim 7, wherein the mounting positions of at least one of the slide pins or the cylinder body holding member of the two dustproof boots are offset in the cylinder body sliding direction. Disc brakes. 11. A spacer is inserted between the end of the dustproof boot and at least one of the slide pin and the cylinder body holding member.
The disc brake according to any one of claims 9 to 10. 12. A pair of slide pins and a cylinder body holding member are provided, and the cylinder body rotation support means is provided at at least one of a pair of slide pin arrangement positions. Disc brake listed in any of. 13. The cylinder body rotation supporting means comprises:
The disc brake according to any one of claims 1 to 11, further comprising a canceling unit capable of canceling a change in the rotational moment value that changes due to the movement of the cylinder body. 14. The cylinder body rotation supporting means is composed of an elastic body, and the canceling means is such that the sliding amount of the cylinder body and the strain amount of the elastic body are interlocked with each other, and the strain amount of the elastic body changes. The disc brake according to claim 12, wherein the disc brake has an elastic modulus capable of canceling the change of the rotation moment. 15. A pair of slide pins and a cylinder body holding member are provided, wherein the diameters of the sliding holes of the pair of cylinder body holding members are different and the diameters of the pair of slide pins are the same. 15. The disc brake according to claim 14.