JP2002340056A - Disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disc brake capable of reducing squeal in proceeding in either direction. SOLUTION: This disc brake comprises a brake pad 2 disposed at a facing position to a disc rotor 1, a torque bearing member 3 to movably support the brake pad 2 in the perpendicular direction to the disc rotor 1, and a piston 4 movable in the perpendicular direction to the disc rotor 1. It also comprises a pressing device 5 for pressing the brake pad 2 to the disc rotor 1 by a piston 4. The brake pad 2 is moved to a trailing side by friction with the disc rotor 1, so that contact surface pressure of the piston 4 on the trailing side to the brake pad 2 becomes larger than contact surface pressure on a leading side to the brake pad 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake, and more particularly, to reduction of so-called squeal during braking.

[0002]

2. Description of the Related Art A disc brake is provided at a position opposed to a disc rotor fixed to a rotating shaft (not shown) with a disc rotor interposed therebetween, and the brake pad can be moved in a direction perpendicular to the disc rotor. A torque receiving member that supports the brake pad, at least one piston movable in a direction perpendicular to the disk rotor, and a pressing device that presses the brake pad against the disk rotor by pressing the brake pad with the piston. It is configured.

In such a disk brake, noise called squeal may be generated. This is a self-excited vibration phenomenon caused by a frictional force between the brake pad and the disk rotor. When the squealing occurs, the occupants of the vehicle and the people around them are uncomfortable.

[0004] As a method of reducing such a squeal,
There are a method of reducing the vibration energy itself generated by self-excitation due to the frictional force between the brake pad and the disk rotor, and a method of attenuating the vibration energy to increase the dissipated energy.

As a method of reducing the self-excited vibration energy generated by the frictional force, it is effective to reduce the frictional force on the leading side between the brake pad and the disk rotor and increase the frictional force on the trailing side. It is known that a part of the leading side of the brake pad is cut, or a shim with the leading side notched is interposed between the piston and the brake pad.

[0006] The brake pad described in Japanese Patent Application Laid-Open No. 2000-120736 reduces the contact surface pressure on the leading side between the brake pad and the disk rotor by reducing the hardness of the sliding material on the leading side. The frictional force on the leading side is reduced, the hardness of the sliding material on the trailing side is increased, and the contact surface pressure between the brake pad and the trailing side of the disc rotor increases.
By increasing the frictional force on the trailing side, self-excited vibration of the brake pad is suppressed, preventing the occurrence of squeal.

On the other hand, as a method of increasing the dissipated energy due to the damping, an anti-vibration shim is attached to a brake pad, or a material having a high damping ability is used as a sliding material of the brake pad. . In the disc brake described in Japanese Patent Application Laid-Open No. Hei 7-301261, the contact surface between the piston and the brake pad is inclined in a direction approaching the disc rotor toward the leading end, so that the contact between the piston and the brake pad is increased. By inclining the direction of the force, the sliding resistance between the cylinder supporting the piston and the piston increases, and the absorption of vibration energy of the brake pad and the piston increases, thereby preventing squeal.

[0008]

A method of dissipating vibration energy by increasing the damping capacity of a disc brake structure is as follows.
This is not a fundamental solution in that the self-excited vibration energy is not reduced, and a squeal may occur when the damping capacity is reduced due to aging or the like. Also, the method of adding damping capacity to the brake pad is effective for high-frequency squeal generated by deformation of the brake pad, but is effective for low-frequency squeal generated by the rigid movement of the brake pad. There is a problem that there is no.

On the other hand, the conventional method of reducing the self-excited vibration energy by reducing the frictional force on the leading side between the brake pad and the disk rotor is effective only when the traveling direction is one direction. For example, when the traveling direction is not one direction such as a railway vehicle, the leading side and the trailing side of the brake pad are switched depending on the traveling direction, so that there is a problem that occurrence of squeal cannot be prevented when traveling in either direction. .

Therefore, the disk brake according to the present invention has been made to solve the above-mentioned problems of the prior art. Even when the traveling direction is not one direction, the disk brake reduces self-excited vibration energy. Another object of the present invention is to provide a disc brake capable of reducing high frequency noise and low frequency noise.

[0011]

A disk brake according to the present invention has a brake pad disposed at a position opposed to a disk rotor, and the brake pad can be moved in a direction perpendicular to the disk rotor. And at least one piston movable in a direction perpendicular to the disk rotor, and pressing the brake pad with the piston to press the brake pad against the disk rotor. In the disc brake having the device, the brake pad moves to the trailing side of the disc rotor by a frictional force when pressed against the disc rotor, so that the piston comes into contact with the brake pad on the trailing side. The area of the brake pad on the leading side of the piston It is characterized in that it has configured to be larger than the contact area.

[0012] Another structure of the disk brake according to the present invention includes a brake pad provided at a position facing the disk rotor and a torque for supporting the brake pad movably in a direction perpendicular to the disk rotor. A disk having a receiving member and at least one piston movable in a direction perpendicular to the disk rotor, and having a pressing device for pressing the brake pad against the disk rotor by pressing the brake pad with the piston. In the brake, by moving the brake pad to the trailing side of the disk rotor by frictional force when pressing the disk rotor, the trailing side rigidity of the contact portion of the brake pad with the piston is Characterized by being higher than the rigidity on the leading side of the contact portion. It is.

Still another configuration of a disk brake according to the present invention is a brake pad disposed at a position opposed to a disk rotor, and supports the brake pad movably in a direction perpendicular to the disk rotor. It has a torque receiving member and at least one piston movable in a direction perpendicular to the disk rotor, and has a pressing device for pressing the brake pad against the disk rotor by pressing the brake pad with the piston. In the disk brake, the frictional force between the brake pad and the disk rotor causes the brake pad to move to the trailing side, so that the trailing side rigidity of the contact portion of the piston with the brake pad is reduced. It is configured to be higher than the rigidity on the leading side of the contact part It is an feature.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a disc brake according to the present invention will be described with reference to FIGS.

[Embodiment 1] FIG. 1 is a sectional view of a disc brake according to an embodiment of the present invention. As shown in the figure, the disk brake is disposed at a position opposed to a disk rotor 1 fixed to a rotating shaft (not shown) and rotatable about the rotating shaft and friction surfaces 1a on both sides of the disk rotor 1. A pair of brake pads 2, a torque receiving member 3 for supporting the brake pads 2 movably in a direction perpendicular to the disk rotor 1, and a cylinder 8 containing a piston 4 for pressing the brake pads 2.
And a pressing device 5 comprising a caliper 7 for connecting the pair of brake pads 2.

The disk rotor 1 is fixed to a rotating shaft (not shown) and is rotatable around the rotating shaft. The rotating direction is indicated by an arrow R, and its reciprocating side (left side in the figure) is a leading side. The circulation side (the right side in the figure) is called a trailing side.

The brake pads 2 are provided one by one at positions facing each other with the disk rotor 1 interposed therebetween, slidably supported by a torque receiving member 3, and a friction member 21 slidably in contact with the disk rotor 1. And a metal back metal 20 attached to the friction member 21. The metal backing metal 20 is not always necessary and reinforces the friction member 21. Depending on the material of the friction member 21, the brake pad 2 is integrally formed. Therefore.
In the present specification, for example, “the provided on the metal backing metal 20 of the brake pad 2...”, “The provided on the brake pad 2...”, And “the friction member 21 of the brake pad 2 "Pressing the disk rotor 1 ..." means "the brake pad 2 presses the disk rotor 1 ...".

The caliper 7 of the pressing device 5 is formed in a saddle shape straddling the pair of brake pads 2 and the disk rotor 1, and is connected by a connecting portion passing through the outer peripheral side of the disk rotor 1. On both sides of the brake pad 2, 1
The cylinder 8 is provided in
Is formed with a cylinder bore 22. A piston 4 of the pressing device 5 is fitted to the cylinder bore 22 so as to be movable in a direction perpendicular to the disk rotor 1, and a hydraulic chamber 9 is formed between the piston 4 and the cylinder bore 22. . A circular concave portion 10 having a diameter Lh is formed in the piston 4, and a circular convex portion 11 having a diameter Lp is formed on a contact surface of the brake pad 2 pressed by the piston 4 with the piston 4. ing.

The torque receiving member 3 slidably supports the leading end and the trading end of the brake pad 2 in a direction perpendicular to the rotation direction R of the disk rotor 1. The hydraulic chamber 9 is connected to a pressurizing chamber (not shown) of the master cylinder through a hydraulic oil flow path.
An annular seal groove 17 is formed in the cylinder 8, and a seal member 18 is mounted in the seal groove 17 to maintain the liquid tightness between the piston 4 and the cylinder 8.

FIG. 2 is a sectional view of the disk brake shown in FIG.
It is sectional drawing. As shown in FIG.
Has an end parallel to the moving direction R of the disk rotor 1 and an end perpendicular thereto, and has a horizontally long rectangular shape. At the vertical end of the metal back metal 20 of the brake pad 2, the leading side and the trailing side are respectively provided.
In the moving direction of the disk rotor 1, a torque receiving groove 6 having a predetermined width and length, one end of which is open, and the other end of which is terminated is provided.

The torque receiving groove 6 has the disk rotor 1
The torque receiving member 3 is inserted so as to be in contact with the width direction of the torque receiving groove 6 in a direction perpendicular to the above. The torque receiving member 3 is fixed to a non-rotating member continuous with the caliber 7. Between the torque receiving member 3 and the end of the torque receiving groove 6, a gap 19 having a length G is formed on each of the leading side and the trailing side. The end of the torque receiving groove 6 and the side surface of the torque receiving member 3 receive the rotational torque in the circumferential direction of the disk rotor 1 received when the brake pad 2 slides on the disk rotor 1. I have.

With reference to FIGS. 1, 2, 3, and 4, the operation of the disk brake having the above-described structure will be described. FIG. 3 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 1, and FIG. 4 is a cross-sectional view of the disc brake of FIG.

In the initial stage of braking, when a hydraulic pressure is generated in the pressurizing chamber of the master cylinder, the hydraulic pressure is transmitted to the hydraulic pressure chamber 9, and the piston 4 moves forward in a direction perpendicular to the disk rotor 1, and the brake pad 2 is pressed against the disk rotor 1. At this time, the piston 4 and the brake pad 2
2 is in contact with the cross-hatched ring shown in FIG. 2, and the trailing side and the leading side of the brake pad 2 are in contact with the same area.

When the braking progresses, the brake pad 2
Rotates together with the disk rotor 1 by frictional force with the disk rotor 1. As a result, the brake pad 2
Abuts on the trailing side torque receiving member 3 at a position shifted toward the trailing side by the length G of the gap 19 between the torque receiving groove 6 and the torque receiving member 3. This gap 1
The length of 9 is approximately 1.2 mm to 2 mm in comparison between the reliability of the brake and the effect of reducing the squeal. FIG. 3 illustrates this state. The torque receiving member 3 receives the movement of the brake pad 2 due to the frictional force between the disk rotor 1 and the brake pad 2, and stops the movement of the brake pad 2. As a result, a braking torque is generated between the brake pad 2 and the disk rotor 1.

When the brake pad 2 moves to the trailing side by a distance G with respect to the piston 4, the contact surface between the brake pad 2 and the piston 4 shifts to the right, and the annular cross-section shown in FIG. The hatched portion changes to the portion shown by cross hatching of the right chord circular arc shown in FIG. That is, the contact area between the piston 4 on the trailing side and the brake pad 2 with respect to the center of the brake pad 2 is larger than the contact area between the piston 4 on the leading side with respect to the center of the brake pad 2 and the brake pad 2.

For this reason, the pressing force from the piston 4 to the brake pad 2 is greater on the trailing side than on the leading side, and the contact surface pressure between the brake pad 2 and the disc rotor 1 is greater on the trailing side. The squeal can be reduced by being larger than the leading side.

In the present embodiment, the leading side and the trailing side of the piston 4 and the brake pad 2 are symmetrical to each other, so that the rotation direction of the disk rotor 1 is reversed and the traveling direction of the vehicle is reversed. However, the squeal can be reduced by changing the contact surface pressure by moving the brake pad 2 in the rotation direction.

In the present embodiment, the length Lp of the protrusion 11 of the brake pad 2 in the rotation direction of the disk rotor 1 in the disk rotor 1 is set.
However, this is a case where the length Lh of the recess 10 of the piston 4 in the rotation direction of the disk rotor 1 in the rotation direction is slightly shorter than the sum of twice the length G of the gap 19. In this case, when the brake pad 2 moves to the trading side by the length G of the gap 19 due to the frictional force with the disk rotor 1, the trading side end of the convex portion 11 of the brake pad 2 comes into contact with the piston 4, and The leading end of the projection 11 does not come into contact with the piston 4.

Therefore, the contact force on the leading side between the brake pad 2 and the piston 4 becomes very small, and the contact force on the trading side between the brake pad 2 and the piston 4 becomes very large. As a result, the contact surface pressure on the leading side between the brake pad 2 and the disk rotor 1 is small, and the contact surface pressure on the trailing side is large, so that squeal can be effectively reduced.

When the difference between the lengths Lp and Lh exceeds twice the length G of the gap 19, ie, 2G, the convex portion 1 of the brake pad 2
Since the leading side end of 1 is in contact with the piston 4, the difference between the contact areas on both sides is reduced, and the effect of reducing squeal is reduced. Also in this case, the contact area between the piston 4 on the trailing side from the center of the brake pad 2 and the brake pad 2 becomes larger than the contact area on the leading side, so that an effect of reducing squeal can be expected.

The shape of the protrusion 11 of the brake pad 2 and the shape of the recess 10 of the piston 4 may be a shape other than a circle or an ellipse, and may be constituted by a plurality of protrusions 11 or recesses 10. Absent. When there are a plurality of protrusions 11 of the brake pad 2, a leading end of the protrusion 11 that is closest to the leading side of all the protrusions 11 and a trailing end of the protrusion 11 that is closest to the trailing side of all the protrusions 11. The distance from the side end is Lp. The same applies to the case where there are a plurality of recesses 10 of the piston 4, the leading end of the most recessed side among all the recesses 10, and the trailing side of the most trailing side of all the recesses 10. The distance between the ends is L
h.

[Embodiment 2] Another embodiment of the disc brake according to the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view of another embodiment of the disc brake according to the present invention, and FIG. 6 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. [Embodiment 2] of FIG.
1 is substantially the same as [Embodiment 1] in FIG. 1, but in [Embodiment 2], the concave portion 10 of the piston 4 has the same specification, but the convex portion 11 of the brake pad 2 is elliptical. The points are different. This difference will be mainly described. FIG.
[Embodiment 2] in FIG. 1 [Embodiment 1]
The members having the same reference numerals as those of the reference numerals have the same functions and the same specifications, and the description thereof will not be repeated.

As shown in FIG. 5, the inner diameter Lh in the concave portion 10 of the piston 4 is parallel to the rotation direction of the disk rotor 1.
(Hereinafter, the inside diameter Lh of the concave portion 10) is the minor axis Lp (hereinafter, the minor axis Lp of the convex portion 11) of the convex portion 11 of the brake pad 2 parallel to the rotation direction of the disk rotor 1 and the length of the gap 19. This is the case where it is slightly shorter than the sum of twice G. In this case, it is necessary that the length of the major axis Lq in the direction perpendicular to the length Lp of the convex section 11 is longer than the internal diameter Lh of the concave section 10. This is brake pad 2
Is to prevent the protrusion 11 from being inserted into the recess 10 of the disk rotor 1.

In the initial stage of braking, between the piston 4 and the brake pad 2, the elliptical leading end and the trading end of the convex portion 11 of the brake pad 2 do not contact the concave portion 10 of the piston 4. FIG. 5 shows this state. However, the upper and lower arcs indicated by cross hatching are in contact with each other, and the trailing side and the leading side of the brake pad 2 are in contact with the same area.

When braking is in progress, the brake pad 2 moves to the leading side by the length G of the gap 19 due to the frictional force with the disk rotor 1, and the brake pad 2
, The leading end of the elliptical projection 11 does not contact the piston 4, but the trailing end of the elliptical projection 11 contacts the piston 4.

Accordingly, as shown in FIG. 6, the contact portion is formed as an arc in which the upper and lower right chords are continuous, the contact force between the piston 4 and the brake pad 2 on the leading side is small, and the contact force on the trailing side is small. growing. As a result, the contact surface pressure on the leading side between the brake pad 2 and the disk rotor 1 is small, and the contact surface pressure on the trailing side is large, so that squeal can be effectively reduced.

When the difference between the inner diameter Lh of the concave portion 10 of the piston 4 and the minor diameter Lp of the convex portion 11 of the brake pad 2 exceeds 2 G, the trailing end of the convex portion 11 of the brake pad 2 also becomes 4, the effect of reducing the squeal becomes small. Even in this case, the bi-convex recesses 11
The contact portion of 10 is an arc in which the upper and lower right strings are discontinuous,
Since the contact area between the piston 4 and the brake pad 2 on the trailing side is larger than the contact area on the leading side from the center of the brake pad 2, an effect of reducing squeal is produced.

From the above, the difference between the short diameter Lp of the convex portion 11 of the brake pad 2 and the inner diameter Lh of the concave portion 10 of the piston 4 is determined by the gap between the torque receiving groove 6 and the torque receiving member 3 of the brake pad 2. When the length is smaller than twice the 19-length G, the squeal can be reduced particularly effectively. In the above, the recess 1
Although the case where the inner diameter Lh of 0 is larger than the shorter diameter Lp of the convex portion 11 has been described, the squeal can be effectively reduced even if the size relationship is reversed.

[Embodiment 3] Still another embodiment of the disc brake according to the present invention will be described with reference to FIGS. FIG. 7 is a cross-sectional view of still another embodiment of the disc brake according to the present invention, and FIG. 8 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. [Embodiment 3] of FIG. 7 is substantially the same as [Embodiment 2] of FIG. 5, in which the convex portion 11 of the brake pad 2 is elliptical, but the length Lh of the concave portion 10 of the piston 4 is small. This is a case where the length Lp of the protrusion 11 of the brake pad 2 is substantially equal.
In this case as well, the length of the major axis Lq in the direction perpendicular to the minor axis Lp of the projection 11 needs to be longer than the internal diameter Lh of the recess 10.

In the initial stage of braking, between the piston 4 and the brake pad 2, the elliptical leading end and the trading end of the convex portion 11 of the brake pad 2 do not contact the concave portion 10 of the piston 4. In the discontinuous arc of the upper and lower chords indicated by cross-hatching, they are in contact with each other, and the trailing side and the leading side of the brake pad 2 are in contact with the same area. FIG. 7 shows this state.

As the braking progresses, the brake pad 2 moves to the leading side by the length G of the gap 19 due to the frictional force with the disk rotor 1. At this time, the leading end of the elliptical convex portion 11 of the brake pad 2 does not come into contact with the concave portion 10 of the piston 4.
The trailing side end of the abutment 1 is in contact with the recess 10. Therefore, as shown in FIG. 8, the contact portion is an arc having a continuous width G in a right chord shape.

Therefore, the brake pad 2 and the piston 4
And the contact force on the leading side with the trailing side increases. As a result, the contact surface pressure on the leading side between the brake pad 2 and the disk rotor 1 is small, and the contact surface pressure on the trailing side is large, so that squeal can be effectively reduced.

[Embodiment 4] Still another embodiment of the disc brake according to the present invention will be described with reference to FIG. FIG. 9 is a sectional view of still another embodiment of the disc brake according to the present invention. [Embodiment of FIG.
4] is almost the same as [Embodiment 1] of FIG. As shown in FIG. 9, the difference is that the protrusion 11 of the brake pad 2 is a shim 12 which is a separate component from the brake pad 2. This difference will be mainly described. In [Embodiment 4] of FIG. 9, members having the same reference numerals as those of [Embodiment 1] of FIG.

The shim 12 is provided on the protrusion 11 of the brake pad 2.
The piston 4 presses the brake pad 2 via the shim 12 at the initial stage of braking, in which the entire height including the central portion and both end portions has the same size. Will do. Therefore, it is preferable that the shim 12 is fixed to the brake pad 2. FIG. 9 shows this state.

As the braking progresses, the brake pad 2
Attempts to rotate with the disk rotor 1 due to frictional force with the disk rotor 1. As a result, the brake pad 2 has a gap 1 between the torque receiving groove 6 and the torque receiving member 3.
At a position moved to the trailing side by a length G of 9, it comes into contact with the torque receiving member 3 on the trailing side. The shim 12 also moves to the trailing side by the length G of the gap 19, and is pressed by the piston 4 in that state.

At this time, the relationship between the length Lp of the shim 12, the length Lh of the concave portion of the piston 4, and the length G of the gap 19 is as follows.
Since it is almost the same as [Embodiment 1], the piston 4 on the trailing side of the center of the brake pad 2 and the shim 1
2 is larger than the contact area between the piston 4 and the shim 12 on the leading side of the center of the brake pad 2. As a result, the contact surface pressure on the trailing side between the brake pad 2 and the disk rotor 1 increases, and squeal is suppressed. When the shim 12 is used, selection of materials and structures can be diversified.

[Embodiment 5] Still another embodiment of the disk brake according to the present invention will be described with reference to FIGS. FIG. 10 is a cross-sectional view of still another embodiment of the disc brake according to the present invention, and FIG. 11 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG.

[Embodiment 5] of FIG. 10 is substantially the same as [Embodiment 1] of FIG. 1, except that the piston 4 does not form a concave portion having a central portion formed therein, and has a columnar, cylindrical or cylindrical shape. The present embodiment is different from the first embodiment in that the contact surface between the piston 4 and the protrusion of the brake pad 2 is formed in a V-shape. This difference will be mainly described. In [Embodiment 5] of FIG. 9, members having the same reference numerals as those of [Embodiment 1] of FIG. 1 have the same functions and the same specifications, and thus the description thereof will not be repeated.

In FIG. 10, the projection 11 provided on the columnar, cylindrical or square member provided on the brake pad 2 has an inverted V-shaped surface in contact with the piston 4. The concave portion 10 provided on the columnar, cylindrical or square member of the piston 4 is formed in an inverted V-shaped surface so as to be in close contact with the inverted V-shaped convex portion 11 provided on the brake pad 2. Have been.

As shown in FIG. 10, at the beginning of braking,
The piston 4 and the brake pad 2
When viewed from the center, both the leading end and the trading end are in contact with the recess 10 of the piston 4 in the same area.

As shown in FIG. 11, when braking progresses, there is a gap 19 having a length G between the torque receiving member 3 and the torque receiving groove 6 of the brake pad 2, so that when the disc rotor 1 rotates, The brake pad 2 moves to the trailing side by a distance G. At this time, the inverted V-shaped contact surface between the piston 4 and the brake pad 2 forms a gap on the slope of the inverted V-shaped contact surface on the leading side from the center of the brake pad 2 and does not contact. On the other hand, the trailing side from the center of the brake pad 2 comes into contact with the slope of the inverted V-shaped contact surface. Therefore, the pressing force from the piston 4 to the brake pad 2 increases on the trailing side.

Therefore, the contact surface pressure between the brake pad 2 and the disk rotor 1 is greater on the trailing side than on the leading side, so that squeal can be reduced. The shape of the contact surface between the piston 4 and the brake pad 2 may be a constant V-shaped surface formed in a direction perpendicular to the rotation axis, or a conical surface concentric with the center of the piston 4. No problem.

The disc brake according to the first to fifth embodiments has a gap 19 between the brake pad 2 and the torque receiving member 3 for allowing the brake pad 2 to move in the rotation direction of the disc rotor 1. By moving the brake pad 2 toward the trailing side by the frictional force between the brake pad 2 and the disc rotor 1, the contact area between the piston 4 and the brake pad 2 on the trailing side of the center of the brake pad 2 is increased. Is larger than the contact area on the leading side of the center of the brake pad 2. The contact surface pressure between the brake pad 2 and the disk rotor 1 is also greater on the trailing side than on the leading side, and squeal is reduced.

[Embodiment 6] FIGS. 12, 13, and 1
Referring to FIG. 4, still another embodiment of the disc brake according to the present invention will be described. FIG. 12 is an explanatory view of still another embodiment of the disc brake according to the present invention.
FIG. 14 is a sectional view taken along line AA of the disc brake shown in FIG.
FIG. 13 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG.

[Sixth Embodiment] In FIG. 12, a slit 13 is provided in the leading and trailing portions of the back metal members 20a and 20b of the brake pad 2 so that the brake pad 2 contacts the piston 4. The difference is that the rigidity of the contact portion decreases from the center of the brake pad 2 toward the leading and trailing ends. This difference will be mainly described. In [Embodiment 6] of FIG. 12, members having the same reference numerals as those of [Embodiment 1] of FIG. 1 have the same functions and the same specifications, and thus the description thereof will not be repeated.

As shown in FIG. 12, the brake pad 2
A slit 13 having a predetermined length is arranged along the center in the thickness direction in a direction parallel to the moving direction of the disk rotor 1. Therefore, the rigidity of the contact portion with the piston 4 is the highest in the central portion, and the rigidity is reduced so that the rigidity becomes the same from the central portion to the leading and trailing ends. As shown in FIG. 13, the center of the piston 4 is cut, and only the left and right arc portions (hatched portions) press the brake pad 2.

In the initial stage of braking, as shown in FIG. 12, the leading and trailing pistons 4 and the brake pad 2 are viewed from the center of the brake pad 2.
Are arranged symmetrically, and the rigidity on the leading side and the rigidity on the trailing side are also the same. The right and left arc portions of the piston 4 shown in FIG. 13 also press the brake pad 2 at symmetric positions. Therefore, when viewed from the center of the brake pad 2, the contact surface pressure on the leading side and the contact surface pressure on the trailing side are the same.

As the braking progresses, the disk rotor 1 rotates and moves in the R direction in the figure, and the disk rotor 1 is changed from the state of the disk brake at the initial braking shown in FIG.
The friction force between the brake pad 2 and the brake pad 2
Moves to the leading side, and the state of the disc brake shown in FIG. 14 is obtained. Therefore, the rigidity of the contact portion of the brake pad 2 with the piston 4 is higher on the trailing side than on the center of the piston 4 than on the leading side than the center of the piston 4. As shown in FIG. 13, the left and right arc portions of the piston 4 also do not press the brake pad 2 at symmetrical positions, the trailing side is at a position outside the slit 13, and the leading side is at the center of the slit 13. Press each in the vicinity.

Therefore, the brake pad 2 and the piston 4
The contact area on the leading side with the disc rotor 1 and the brake pad 2 on the leading side is smaller than the contact area on the leading side with respect to the trailing side. Can be reduced.

[Embodiment 7] Still another embodiment of the disc brake according to the present invention will be described with reference to FIGS. FIG. 15 is an explanatory view of still another embodiment of the disc brake according to the present invention, and FIG. 16 is an explanatory view of a state where the brake pad has moved to the training side in the disc brake of FIG.

In this embodiment, since the change in the contact area is used in [Embodiment 4] of FIG. 9, the shim 12 provided with the brake pad 2 has a central portion and both ends have a disk-like shape having the same thickness. The shim 1 has a small thickness at the leading and trailing ends from the center of the brake pad 2 in order to utilize the change in rigidity.
2 is different. This difference will be mainly described. In [Embodiment 7] of FIG. 15, members having the same reference numerals as those of [Embodiment 4] of FIG. 9 have the same functions and the same specifications, and thus the description thereof will not be repeated.

As shown in FIG. 15, in the initial stage of braking, the thickness of the shim 12 from the center of the brake pad 2 to the leading and trailing ends is reduced toward the ends. Therefore, the brake pad 2 comes into contact with the piston 4 in a state where the rigidity is high at the central portion of the brake pad 2 and the rigidity is substantially the same at the leading and trailing ends from the central portion.

As the disk rotor 1 rotates,
From the state of the disk brake in the initial stage of the braking shown in FIG. 15, the state of the disk brake shown in FIG. 16 in which the brake pad 2 and the shim 12 move to the leading side by the frictional force between the disk rotor 1 and the brake pad 2 is obtained.
Therefore, the shim 12 is pressed by the thin portion of the shim 12 at the leading end of the piston 4 and by the thick portion of the shim 12 at the trailing end.

As a result, the rigidity of the contact portion of the brake pad 2 with the piston 4 is higher on the trailing side than on the center of the piston 4 than on the leading side than the center of the piston 4. Therefore, the brake pad 2
The contact force at the leading contact surface between the piston and the piston 4 is smaller than the contact force at the trailing contact surface on the trailing side. Since the contact pressure is lower than the contact surface pressure, the squeal is reduced.

[Embodiment 9] Referring to FIG. 17, another embodiment of the disc brake according to the present invention will be described. FIG. 17 is an explanatory diagram of still another embodiment of the disc brake according to the present invention.

In the shim 12 of [Embodiment 4] of FIG.
The center and both ends have the same height, and the whole has a disk-like shape made of the same material. However, in the shim 12 shown in FIG. 17 [Embodiment 9], the metal material 14 shown by hatching and the cross hatching This is different from the above in that it is composed of a damping material 15 (for example, rubber having damping properties). In [Embodiment 9] of FIG. 17, [Embodiment 9] of FIG.
Members having the same reference numerals as those of [4] are members having the same functions and the same specifications, and thus the description thereof will not be repeated.

In FIG. 17, the shim 12 is composed of a metal material 14 for maintaining rigidity indicated by hatching and a damping material 15 indicated by cross hatching. The structure is such that the proportion of the damping material 15 increases as it approaches the end on the ring side.

In the initial stage of braking, the metal material 14 of the shim 12 and the vibration damping material 1 are viewed from the center of the brake pad 2.
5 has the same ratio at any of the contact positions of the piston 4 and the brake pad 2. For this reason, the rigidity of the shim 12 on the leading side and the trailing side is the same, and the function based on the metal material 14 and the vibration damping material 15 is also the same. Therefore, when the piston 4 presses the brake pad 2 via the shim 12, the contact surface pressures on the leading side and the trailing side when viewed from the center of the brake pad 2 are the same.

The braking proceeds, the disk rotor 1 rotates,
When moved in the R direction, a detailed illustration is omitted from the state of the disc brake in the initial stage of braking shown in FIG.
By the frictional force between the disc rotor 1 and the brake pad 2,
The brake pad 2 moves to the trail leading side. For this reason, the contact portion between the piston 4 and the brake pad 2
On the trailing side, the ratio of the damping material 15 of the shim 12 is low, and the shim 12 moves to a position where the ratio of the metal material 14 is high. On the leading side, the ratio of the damping material 15 of the shim 12 is high, and Move to a position with a small percentage.
Therefore, the rigidity of the shim 12 is higher on the trail leading side than on the center of the piston 4 than on the leading side.

As a result, the rigidity of the contact portion of the brake pad 2 with the piston 4 is higher on the trailing side than on the center of the piston 4 than on the leading side than the center of the piston 4. For this reason, the contact force between the brake pad 2 and the piston 4 on the trading side contact surface becomes larger than the contact force on the leading side contact surface.
Since the contact surface pressure on the leading side between the disk rotor 1 and the brake pad 2 is lower than the contact surface pressure on the trailing side, squeal can be reduced.

[Embodiment 10] With reference to FIGS. 18 and 19, still another embodiment of the disc brake according to the present invention will be described. FIG. 18 is an explanatory diagram of still another embodiment of the disc brake according to the present invention, and FIG. 19 is an explanatory diagram of a state where the brake pad has moved to the training side in the disc brake of FIG.

[Embodiment 10] In the tenth embodiment, as shown in FIG. 18, the piston 4 is provided with a cantilever which comes into contact with the brake pad 2, and the brake pad 2 is provided with a projection which comes into contact with the cantilever. Is different. This difference will be mainly described. In [Embodiment 9] of FIG. 18, members having the same reference numerals as those of [Embodiment 1] of FIG. 1 are members having the same function and the same specifications, and thus the description thereof will not be repeated.

In FIG. 18, the concave portion 10 of the piston 4 is provided with a cantilever La on the leading side toward the inside of the concave portion 10 on the contact surface with the brake pad 2 and the cantilever Lb on the trading side. ing. For this reason, the rigidity of the contact surface of the piston 4 with the brake pad 2 increases as the positions on the trading side and the leading side increase. Further, the brake pad 2 is provided with protrusions Ca and Cb so as to abut against the cantilever beams La and Lb, respectively.

In the initial stage of braking, the cantilever beams La, Lb and the convex portions Ca, Cb abut at symmetrical positions on the trading side and the leading side, respectively, as viewed from the center of the brake pad 2. Accordingly, the rigidity of the abutting portion between the trailing-side and leading-side piston 4 and the brake pad 2 is the same, and the rigidity of the trailing-side and leading-side viewed from the center of the brake pad 2 is the same. Therefore, the contact force and the contact surface pressure between the piston 4 and the brake pad 2 are the same on both the trailing side and the leading side.

As the braking progresses and the brake pad 2 moves to the trailing side due to the frictional force between the disc rotor 1 and the brake pad 2 as shown in FIG. The position of the contact portion is closer to the trailing end of the concave portion 10 of the piston 4, and the position of the contact portion between the cantilever Lb and the convex portion Cb is far from the leading end of the concave portion 10 of the piston 4. Move,
The rigidity on the trailing side of the center of the brake pad 2 is higher than the rigidity on the leading side of the center of the brake pad 2.

Therefore, the piston 4 and the brake pad 2
The contact force on the leading side with the disc rotor 1 and the brake pad 2 on the leading side is smaller than the contact force on the leading side with respect to the trailing side. Squeal can be reduced. The cantilever shown in FIG. 18 may be a disc-shaped flange.

[Embodiment 11] Still another embodiment of the disc brake according to the present invention will be described with reference to FIGS. FIG. 20 is an explanatory view of still another embodiment of the disc brake according to the present invention, and FIG. 21 is an explanatory view of a state where the brake pad has moved to the trailing side in the disc brake of FIG.

[Embodiment 11] As shown in FIG. 20, the piston 4 does not have the recess 10 provided in [Embodiment 1] or the like, and leads and trails the contact surface with the brake pad 2. Piston shims 16a and 16b are provided on the sides, respectively. In [Embodiment 11] of FIG. 20, members having the same reference numerals as those of [Embodiment 1] of FIG. 1 have the same functions and the same specifications, and thus the description thereof will not be repeated.

Each of the piston shims 16a and 16b has a predetermined wedge shape, and the leading ends of the wedge-shaped tips on the leading side are directed toward the trailing side, and the leading ends of the wedge-shaped tips on the trailing side are directed toward the leading side. The piston 4 is fixed to a contact portion with the brake pad 2 on the leading and trailing side of the piston 4.

The piston shims 16a and 16b have thicker ends on the trailing side and the leading side, and the rigidity is higher at the trailing and leading ends than at the center of the piston 4.

In the initial stage of braking, the piston shims 16a, 16b and the brake pad 2 are located on the trading side and the leading side when viewed from the center of the brake pad 2.
Abuts with the convex portions 11 of the back metal 20 at symmetrical positions. Accordingly, the rigidity of the contact portion between the piston 4 on the trailing side and the leading side and the brake pad 2 is the same, and the contact force and the contact surface pressure are also the same.

As the braking progresses, as shown in FIG.
The frictional force between the disc rotor 1 and the brake pad 2 causes the brake pad 2 to move to the trailing side,
The contact portion between the piston shim 16b and the convex portion 11 of the brake pad 2 is located at a position near the trailing end of the piston 4, and the contact portion between the piston shim 16a and the convex portion 11 of the back metal 20 of the brake pad 2. Is located farther from the leading end of the piston 4, and the rigidity of the brake pad 2 on the trailing side from the center is lower than that of the brake pad 2.
The stiffness on the leading side is higher than the center.

For this reason, the brake pad 2 and the piston 4
The contact force on the leading side with the disc rotor 1 and the brake pad 2 on the leading side is smaller than the contact force on the leading side with respect to the trailing side. Squeal can be reduced. The piston shims 16a and 16b may be discontinuous at the center of the convex portion 11 of the back metal 20 of the brake pad 2 with which the piston 4 abuts, or may be connected at another position in the radial direction of the disk rotor 1. Or a circular link.

[Embodiment 12] Referring to FIG. 22, another embodiment of the disc brake according to the present invention will be described. FIG. 22 is an explanatory diagram of still another embodiment of the disc brake according to the present invention. In the present embodiment, the piston shim 16 is composed of the metal material 14 and the vibration damping material 15. In [Embodiment 12] of FIG. 22, members having the same reference numerals as those of [Embodiment 1] of FIG.

The piston shim 16 is composed of a metal material 14 for maintaining rigidity and a vibration damping material 15 for damping vibration. As the distance from the center of the piston 4 to the leading and trailing ends increases, the piston shim 16 becomes more rigid. The ratio of the material 14 is large, and the ratio of the vibration damping material 15 is small.
Although not shown, the metal material 14 and the vibration damping material 15 may be changed continuously (see FIG. 17) or FIG.
As in the present embodiment shown in FIG. For this reason, the rigidity increases from the center of the piston 4 toward the leading and trailing ends.

In the initial stage of braking, the piston shim 16 and the brake shim 16 are symmetrically positioned on the leading side and the trailing side when the ratio of the metal material 14 to the damping material 15 is the same, as viewed from the center of the brake pad 2. The projections 11 of the pad 2 are in contact with each other. Therefore, the rigidity of the contact portions between the trailing-side and leading-side pistons 4 and the convex portions 11 of the brake pads 2 is the same,
The contact force and the contact surface pressure are also the same.

As the braking progresses, the frictional force between the disc rotor 1 and the brake pad 2 moves the brake pad 2 to the trailing side, and the contact between the piston shim 16 and the projection 11 of the brake pad 2 The position is far from the leading end of the piston 4. As a result, the piston 4 abuts at a position where the metal material 14 is large and the vibration damping material 15 is small on the trailing side, and is contacted at a position where the metal material 14 is small and the vibration damping material 15 is large on the leading side. .

Accordingly, the rigidity on the trailing side of the brake pad 2 is higher than the rigidity on the leading side of the brake pad 2. For this reason,
The contact force on the leading side between the brake pad 2 and the piston 4 becomes smaller than the contact force on the trailing side, and the contact surface pressure on the leading side between the disc rotor 1 and the brake pad 2 becomes smaller than the contact surface pressure on the trailing side. Squeal can be reduced.

[Embodiment 7] to [Embodiment 12]
Up to the contact surface of the brake pad 2 with the piston 4
The rigidity on the trailing side of the center of the piston 4 is higher than the rigidity on the leading side of the center of the piston 4. Alternatively, the rigidity of the contact surface of the piston 4 with the brake pad 2 on the trailing side of the center of the brake pad 2 is higher than the rigidity on the leading side of the center of the brake pad 2.

Therefore, the brake pad 2 and the piston 4
When the contact force on the leading side between the disk rotor 1 and the brake pad 2 becomes smaller than the contact surface pressure on the trailing side between the disk rotor 1 and the brake pad 2, the noise is generated. Can be reduced.

Embodiment 13 With reference to FIG. 23, still another embodiment of the disc brake according to the present invention will be described. FIG. 23 is an explanatory diagram of still another embodiment of the disc brake according to the present invention. In the embodiment described above, the disc brake fixed with the caliper and the disc rotor and having the pistons 4 disposed on both sides has been described.

However, as shown in FIG.
Is arranged on one side of the disk rotor 1 and the caliper 7 is movable in a direction perpendicular to the disk rotor 1, and the structure of the disk brake according to the present invention works effectively. Note that a plurality of pistons 4 may be provided on one side or both sides of the disk rotor 1.

In [Thirteenth Embodiment] in FIG. 23, members having the same reference numerals as those in [Embodiment 1] in FIG. 1 have the same functions and the same specifications. The following description focuses on the feature points of the floating type of mode 13].

As shown, the pressing device 5 includes a caliper 7
And the piston 4. The caliper 7 is formed in a saddle shape straddling a pair of brake pads 2 and the disc rotor 1, and has a cylinder 8 for housing the piston 4 on one brake pad 2 side. And the reaction part 3 on the other side
0, and the cylinder 8 and the reaction portion 30 are connected by a connecting portion passing through the outer peripheral side of the disk rotor 1.

One side of the brake pad 2 has a cylinder 8
And a cylinder bore 22 is formed in the cylinder 8. The piston 4 is fitted to the cylinder bore 22 so as to be movable in a direction perpendicular to the disk rotor 1, and a hydraulic chamber 9 is formed between the piston 4 and the cylinder bore 22. The hydraulic pressure chamber 9 is connected to a pressurizing chamber (not shown) of the master cylinder through a hydraulic oil flow path.

The rotation of the wheel causes the disk rotor 1 to rotate, and receives the rotational torque of the disk rotor 1 in the circumferential direction received when the disk rotor 1 comes into sliding contact with the brake pad 2. Is provided. Between the torque receiving groove 6 and the torque receiving member 3, a length G is provided on each of the leading side and the trailing side.
Gap 19 is formed.

The operation of the floating type disk brake will be described. When a hydraulic pressure is generated in the pressurizing chamber of the master cylinder, the hydraulic pressure is transmitted to the hydraulic chamber 9, and the piston 4 advances in a direction perpendicular to the disk rotor 1, and presses the brake pad 2 against the disk rotor 1. . At that time, the caliper 7 moves in a direction away from the disk rotor 1 by the reaction force, and the reaction portion 30 moves to the disk rotor 1 side, so that the brake pad 2 on the reaction portion 30 side is pressed against the disk rotor 1. .

As a result, the two brake pads 2 are pressed against the disk rotor 1, and a frictional force is generated between the brake pad 2 and the disk rotor 1. The frictional force causes the brake pad 2 to form a gap. 19, to the trailing side, and FIG.
Similarly to 1), the contact area and the contact surface pressure on the trailing side are larger than the contact area and the contact surface pressure on the leading side,
Squeal can be reduced.

In the first to thirteenth embodiments described above, in the disc brake, a gap is provided between the brake pad and the torque receiving member, and the brake pad moves within the gap. By doing so, it was configured to move a predetermined amount to the trailing side, but without being limited to this, by bending the torque receiving member, the brake pad, by bending the torque receiving member, It can be moved to the trailing side by a predetermined amount.

[0100]

As described above in detail, the disc brake according to the present invention has a larger contact area on the trailing side than a contact area on the leading side of the piston, and has a larger contact area between the brake pad and the piston. The rigidity on the trailing side is higher than the rigidity on the leading side of the piston. By reducing the contact surface pressure on the leading side between the rotor and the brake pad to be smaller than the contact surface pressure on the trailing side, even if the traveling direction is not one direction, by reducing the vibration energy generated by friction self-excitedly Thus, it is possible to provide a disc brake capable of reducing high frequency noise and low frequency noise.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disc brake according to an embodiment of the present invention.

FIG. 2 is a sectional view of the disk brake taken along line AA of FIG. 1;

FIG. 3 is a cross-sectional view showing a state where a brake pad has moved to a trailing side in the disc brake of FIG. 1;

FIG. 4 is a sectional view of the disk brake taken along line AA of FIG. 3;

FIG. 5 is a cross-sectional view of another embodiment of the disc brake according to the present invention.

FIG. 6 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 5;

FIG. 7 is a sectional view of still another embodiment of the disc brake according to the present invention.

FIG. 8 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 7;

FIG. 9 is a sectional view of a disc brake according to another embodiment of the present invention.

FIG. 10 is a sectional view of still another embodiment of the disc brake according to the present invention.

11 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 10;

FIG. 12 is a sectional view of still another embodiment of the disc brake according to the present invention.

FIG. 13 is a sectional view of the disk brake taken along line AA of FIG. 12;

14 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG.

FIG. 15 is a sectional view of still another embodiment of the disc brake according to the present invention.

16 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG.

FIG. 17 is a sectional view of still another embodiment of the disc brake according to the present invention.

FIG. 18 is a sectional view of still another embodiment of the disc brake according to the present invention.

19 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 18;

FIG. 20 is a sectional view of still another embodiment of the disc brake according to the present invention.

21 is a cross-sectional view showing a state where the brake pad has moved to the trailing side in the disc brake of FIG. 20;

FIG. 22 is a sectional view of still another embodiment of the disc brake according to the present invention.

FIG. 23 is a sectional view of still another embodiment of the disc brake according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc rotor 2 ... Brake pad 3 ... Torque receiving member 4 ... Piston 5 ... Pressing device 6 ... Torque receiving groove 7 ... Caliper 8 ... Cylinder 9 ... Hydraulic chamber 10 ... Recess of piston 11 ... Protrusion of brake pad 12 ... Shim 13 ... Slit of brake pad 14 ... Metal material 15 ... Damping control material 16 ... Piston shim 17 ... Seal groove 18 ... Seal member 19 ... Gap 22 ... Cylinder bore

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Takai 794, Higashi Toyoi, Kazamatsu, Kudamatsu City, Yamaguchi Prefecture Inside the Kasado Works, Hitachi, Ltd. (72) Katsuyuki Iwasaki 794, Higashi Toyoi, Kudamatsu, Yamaguchi Prefecture F term in the Kasado Plant of Hitachi, Ltd. (reference) 3J058 AA48 AA52 AA66 AA69 AA77 AA87 BA21 CA45 CA47 CA60 CC03 CC35 GA92

Claims (7)

[Claims] A brake pad disposed at a position facing the disk rotor, a torque receiving member for supporting the brake pad so as to be movable in a direction perpendicular to the disk rotor, and a brake pad perpendicular to the disk rotor. A disc brake having at least one piston movable in a direction, and pressing the brake pad with the piston to thereby press the brake pad against the disc rotor; The disc rotor moves to the trailing side where the disc rotor rotates by the frictional force at the time of pressing against the rotor, so that the contact area of the piston on the trailing side with the brake pad is reduced. From the contact area of the leading side to the brake pad A disc brake characterized by being configured to be large. 2. A brake pad disposed at a position facing the disk rotor, a torque receiving member for supporting the brake pad so as to be movable in a direction perpendicular to the disk rotor, and a brake pad perpendicular to the disk rotor. A disc brake having at least one piston movable in a direction, wherein the disc pad has a pressing device that presses the brake pad against the disc rotor by pressing the brake pad with the piston. By moving to the trailing side of the disc rotor by the frictional force at the time of pressing, the trailing side rigidity of the contact portion of the brake pad with the piston is higher than the leading side rigidity of the contact portion. Disc brake characterized by becoming. 3. A brake pad disposed at a position facing the disk rotor, a torque receiving member for supporting the brake pad so as to be movable in a direction perpendicular to the disk rotor, and a brake pad perpendicular to the disk rotor. A disc brake having at least one piston movable in a direction, wherein the piston presses the brake pad to press the brake pad against the disc rotor, wherein the brake pad and the disc rotor The frictional force between
By moving the brake pad to the trailing side, the trailing rigidity of the contact portion of the piston with the brake pad is configured to be higher than the leading rigidity of the contact portion. And disc brake. 4. The disc brake according to claim 1, wherein a gap is provided between the brake pad and the torque receiving member, and the brake pad moves within the gap, thereby causing the piston to move. A disc brake, wherein the disc brake moves a predetermined amount from the center to the trailing side. 5. The disc brake according to claim 1, wherein the torque receiving member is configured to bend, and the brake pad bends the torque receiving member to cause the trailing from the center of the piston. A disc brake characterized in that the disc brake is moved to a predetermined side. 6. The disc brake according to claim 4, wherein the piston has a concave portion at a contact portion with the brake pad, and the disc pad has a convex portion at a contact portion with the piston. The difference between the linear length between both ends in the circumferential direction of the disk rotor of the convex portion and the linear length between the circumferential ends of the disk rotor in the concave portion is a predetermined amount by which the brake pad moves to the trailing side. A disc brake characterized by being equal to or less than twice. 7. The disc brake according to claim 4, 5 or 6, wherein the predetermined amount by which the brake pad moves to the trailing side is from 1.2 mm to 2.0 mm.