JP2007198407A - Disk brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique to reduce unevenness of mating face pressure between a disk rotor and a brake pad. <P>SOLUTION: The disk brake device consists of a friction material 32 provided to face against a friction sliding surface of the disk rotor 26 rotating with a wheel, a back metal member 30 having a supporting surface 64 for supporting a surface which is not facing against the disk rotor of the friction material 32 and a surface with a slant surface 60 formed in it, a contact member 34 contacting with the slant surface 60 and a piston 46 for pressing the contact member 34 in a direction parallel to a rotation shaft of the disk rotor 26 and pressing the friction material 32 to the friction sliding surface of the disk rotor 26. The slant surface 60 formed in the back metal member 30 is provided to face against it in approximately parallel and the contact member 34 has a slant surface 70 contacting with the slant surface 60. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disc brake device, and more particularly to a technique for reducing uneven contact surface pressure between a disc rotor and a brake pad.

  In general, in a disc brake device, a pair of brake pads composed of a friction material and a back metal member are disposed with a disc rotor sandwiched between calipers. During vehicle braking, the disc rotor is clamped by the pair of brake pads. In such a disc brake device, since the pressing force of the piston concentrates on the pressing position of the friction material, the brake pad may not be pressed uniformly against the disc rotor. In this case, brake vibration or brake squeal due to uneven surface pressure may occur during braking, or uneven wear of the brake pads may occur.

Various techniques for solving various problems caused by uneven surface pressure of brake pads are known. For example, Patent Document 1 discloses a technique for forming a friction material for a brake pad so that the thickness of a portion where the pressing force is concentrated during braking is larger than the thickness of other portions. Here, since the compression rigidity of the thick part of the friction material is lower than the compression rigidity of the thin part, even if the pressing force by the piston is not uniform, the non-uniform surface pressure of the entire friction material is It is said to be reduced.
JP-A-9-280284

  However, in the technique disclosed in Patent Document 1 described above, it is necessary to secure a certain thickness even for a thin portion, and therefore, if a part of the friction material is increased, the brake pad itself is also increased. In addition, if the thickness of the backing metal member in contact with the part where the friction material is thick is reduced so as not to change the thickness of the brake pad, the thin part of the backing metal member is deformed due to frictional heat generated during braking. May end up.

  The present invention has been made in view of such a situation, and an object thereof is to provide a technique for reducing non-uniform contact surface pressure between a disk rotor and a brake pad.

  In order to solve the above-described problems, a disc brake device according to an aspect of the present invention includes a friction material disposed to face a friction sliding surface of a disc rotor that rotates together with a wheel, and a surface that does not face the disc rotor of the friction material. A back metal member having a first surface for supporting the first surface and a second surface on which a slope is formed; a contact member in contact with the slope formed on the second surface; and a contact member in a direction parallel to the rotational axis of the disk rotor. Pressing means for pressing and pressing the friction material against the friction sliding surface of the disk rotor.

  According to this aspect, when the pressed contact member is pressed against the inclined surface formed on the second surface of the back metal member, a component force of pressing force is generated in a direction perpendicular to the inclined surface. This force propagates in the direction from the pressing position toward the end of the back metal member. This prevents the pressing force from concentrating on the pressing position of the friction material and suppresses the occurrence of uneven surface pressure (hereinafter also referred to as “pad surface pressure”) when the brake pad is pressed against the disc rotor. it can.

  The back metal member and the contact member may be formed such that the front end surface of the contact member does not contact the back metal member when the contact member is in contact with the slope formed on the second surface. According to this aspect, it is possible to avoid the pressing force in the direction parallel to the rotation axis of the disk rotor from directly propagating from the front end surface of the contact member to the friction material. Thereby, it is possible to avoid the pressing force from being concentrated on a part of the friction material, and it is possible to better suppress the situation where the pad surface pressure becomes uneven.

  The slope formed on the second surface may be provided so as to face the substantially parallel surface, and the contact member may have a surface in contact with the slope provided so as to face the second surface. According to this aspect, a component force is generated in a direction perpendicular to the slope by applying a pressing force to the second surface. This force propagates away from the slope. Thereby, the force transmitted from the back metal member to the friction material can be generated in a wider range. Therefore, the pressing force can be propagated to the vicinity of the end portion of the friction material, and the situation where the pad surface pressure becomes uneven can be suppressed more favorably.

  The inclined surface formed on the second surface may be a tapered surface, and the contact member may be a tapered member having a surface in contact with the tapered surface formed on the second surface. According to this aspect, a component force is generated in a direction perpendicular to the slope by applying a pressing force to the second surface. This force propagates radially from the tapered surface. Thereby, the force transmitted from the back metal member to the friction material can be generated in a wider range. Therefore, the pressing force can be propagated to the vicinity of the end portion of the friction material, and the situation where the pad surface pressure becomes uneven can be suppressed more favorably.

  Another aspect of the present invention is also a disc brake device. This device includes a friction material disposed opposite to a friction sliding surface of a disk rotor that rotates with a wheel, a backing member that supports a surface of the friction material that does not face the disk rotor, and a rotation axis of the disk rotor. Pressing means for pressing the backing member in the direction and pressing the friction material against the friction sliding surface of the disk rotor. A slit is formed in a direction substantially parallel to the short direction of the back metal member in the vicinity of the position pressed by the pressing means in the back metal member.

  According to this aspect, when the friction material expands in the longitudinal direction due to heat generation due to friction with the friction sliding surface of the disk rotor, the back metal member that supports the friction material becomes longer than the back metal member due to the expansion of the friction material. Pulled in the direction. At this time, the slit formed in the short direction of the back metal member opens, and the back metal member deforms following the expansion of the friction material. This prevents the back metal member from following the deformation due to the expansion of the friction material and deforming its end to warp. As a result, the situation where the pad surface pressure becomes non-uniform can be suppressed.

  According to the disc brake device of the present invention, nonuniform pad surface pressure can be reduced.

  FIG. 1 is a cross-sectional view of the disc brake device according to the present embodiment cut perpendicularly to the disc rotor. The disc brake device 10 includes a mounting for fixing to a vehicle body (not shown) and a caliper 16 supported by the mounting so as to be displaceable in the left-right direction in FIG. The caliper 16 includes a cylinder portion 58 having a piston 46 therein, and a claw portion 56 that faces the cylinder portion 58 across the disk rotor 26.

  Between the cylinder portion 58 and the claw portion 56, the friction material 32 and the friction material 42 are disposed to face each other with the disk rotor 26 rotating coaxially with the wheels. Back metal members 30 and 40 are attached to the sides of the friction material 32 and the friction material 42 not facing the disk rotor 26, respectively. The back metal member 30 is the friction material 32, and the back metal member 40 is the friction material 42. I support it. Here, the friction material 32, the back metal member 30, the contact member 34 described later, the disc spring 36 and the pin 38 constitute the inner brake pad 33, and the friction material 42 and the back metal member 40 constitute the outer brake pad 43. Hereinafter, the side facing the friction material 32 in the disk rotor 26 is also referred to as “inner side”, and the side facing the friction material 42 is also referred to as “outer side”.

  On the surface of the back metal member 30 that is not attached to the friction material 32, an inclined surface 60 facing substantially parallel is provided. The contact member 34 having an inclined surface in contact with the inclined surface 60 is attached to the back metal member 30 by a pin 38 via a disc spring 36. In a state where the contact member 34 is attached to the back metal member 30, the inclined surface 60 of the back metal member 30 and the inclined surface of the contact member 34 are preferably in contact with each other, and the respective inclined surfaces are angled at the same angle. The structures of the back metal member 30 and the contact member 34 will be described in detail with reference to FIGS.

  The piston 46 is hollow and is disposed at a position where the surface of the contact member 34 that is not in contact with the back metal member 30 can be pressed. In the cylinder portion 58, the piston seal 45 is fitted in an annular groove formed by cutting out the inner peripheral surface of the storage portion 59 for storing the piston 46 along the inner periphery. The piston seal 45 is an annular member for adjusting the distance between the friction material 32 and the disk rotor 26 to be constant, and the inner peripheral surface thereof is in contact with the outer peripheral surface of the piston 46. Further, a pressing surface 50 is formed at the tip of the claw portion 56 so as to come into contact with the surface of the back metal member 40 on the side that does not support the friction material 42. When the piston 46 protrudes in the direction of the disk rotor 26 by the hydraulic pressure supplied from the outside, the friction material 32 is pressed against the inner side of the disk rotor 26 and the reaction force causes the caliper 16 to move in the direction in which the piston 46 protrudes. Is moved in the opposite direction, and the friction material 42 is pressed against the outer side of the disk rotor 26 by the pressing surface 50 of the claw 56. As a result, the disc rotor 26 is clamped by the friction material 32 and the friction material 42, and the wheel is braked.

  FIG. 2 is a view showing the inner brake pad 33 in the AA cross section of FIG. 1. As described above, the back metal member 30 supports the friction material 32 on the surface 64 (hereinafter also referred to as “support surface 64”) to be adhered to the friction material 32. The back metal member 30 is formed with a recess formed by cutting out a surface 66 (hereinafter also referred to as “upper surface 66”) parallel to the support surface 64 on the piston 46 side. This recess is formed in the back metal member 30 by a bottom surface 62 and two slopes 60 extending in the depth direction of FIG. Here, the inclined surfaces 60 are formed so as to face each other in parallel, and the width of the recesses increases from the bottom surface 62 toward the top surface 66.

  The contact member 34 has a surface 70 that contacts the inclined surface 60 (hereinafter also referred to as “inclined surface 70”). The slope 60 and the slope 70 are formed at least at a part of the pressing position of the piston 46. In a state where the slope 60 and the slope 70 are in contact, the bottom surface 72 of the contact member 34 does not contact the bottom surface 62 of the back metal member 30. At the center of each of the back metal member 30 and the contact member 34, a hole for inserting the pin 38 is formed. The pin 38 is inserted through the contact member 34 via the disc spring 36 and the back metal member 30 is also inserted and fixed to the friction material 32, and the contact member 34 is fixed in contact with the back metal member 30. In this way, by fixing the contact member 34 to the back metal member 30, it is possible to suppress the generation of noise due to the contact member 34 vibrating and hitting the back metal member 30 or the piston 46 during traveling of the vehicle.

  FIG. 3 is a view of the inner brake pad 33 as viewed from the upper surface 66 side of the back metal member 30 in a direction parallel to the rotation axis of the disk rotor 26. As described above, the inclined surface 60 of the back metal member 30 and the inclined surface 70 (not shown) of the contact member 34 face each other in parallel over the entire short direction of the back metal member 30.

  Returning to FIG. 2, the piston 46 and the disk rotor 26 are indicated by a two-dot chain line. During vehicle braking, the piston 46 presses the upper surface 74 of the contact member 34 in the direction of the arrow 80 parallel to the rotational axis of the disk rotor 26. As a result, the slope 70 of the contact member 34 is pressed against the slope 60 of the backing member 30 by the pressing force of the piston 46. Here, since the slope 60 and the slope 70 are formed at an angle with respect to the direction of the arrow 80 on which the pressing force acts, the component force of the pressing force in the direction of the arrow 80 on the slope 60, that is, the force perpendicular to the slope 60. And a force parallel to the slope 60 is generated.

  The force perpendicular to the inclined surface 60 propagates in the back metal member 30 while spreading toward the direction away from each other, that is, toward both ends in the longitudinal direction. Thus, since the direction of the force propagating through the inside of the back metal member 30 can be dispersed, the difference due to the portion of the pad surface pressure is reduced. As a result, the pressure of the backing member 30 and the friction material 32, that is, the pressing force concentrates in the vicinity of the center and the pad surface pressure becomes non-uniform, resulting in brake squeal, braking vibration and friction material 32 during braking. Uneven wear can be suppressed.

  Further, as shown in FIG. 3, the surface where the inclined surface 60 and the inclined surface 70 are in contact is formed over the entire lateral direction of the backing member 30, so that the component force in the direction perpendicular to the inclined surface 60 of the pressing force is the friction material 32. It is caused to spread upward. As a result, compared to the case where the pressing force from the piston 46 is transmitted to the friction material 32 in the direction of the arrow 80, the situation in which the pad surface pressure becomes nonuniform is better suppressed, and the above-described brake squeal and the like are suppressed. The effect of increases.

  Further, the bottom surface 72 of the contact member 34 does not contact the bottom surface 62 of the back metal member 30 in the inner brake pad 33. Accordingly, the pressing force applied by the piston 46 does not directly propagate from the bottom surface 72 of the contact member 34 to the bottom surface 62 of the friction material 32. Accordingly, since the pressing force is dispersed while avoiding being concentrated on the pressing position of the friction material 32, that is, near the center of the friction material 32, the difference due to the portion of the pad surface pressure can be reduced. As a result, the effect of suppressing the above-described brake squealing can be obtained better.

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. . For example, the following modifications can be considered.

  FIG. 4 is a cross-sectional view of an inner brake pad according to a modification of the present embodiment cut perpendicularly to the disk rotor 26. In the figure, the same members as those shown in FIG. The inner brake pad 133 includes a friction material 132, a back metal member 130, a contact member 134 and a spring 136. Basically, the configuration is the same as that of the inner brake pad 33 described above with reference to FIG. Here, the difference will be described. As shown in FIG. 4, the back metal member 130 is formed with a recess formed by cutting out the upper surface 166, and the contact member 134 is fixed to the recess by a spring 136. In the inner brake pad 133 shown in FIG. 4, the concave portion of the back metal member 130 and the contact member 134 are formed in a circular shape. The concave portion of the back metal member 130 is formed so that the diameter of the concave portion increases from the bottom surface 162 toward the upper surface 166.

  FIG. 5 is a view of the inner brake pad according to the modification in the direction parallel to the rotation axis of the disk rotor 26 from the upper surface 166 side of the back metal member 130. As shown in the figure, the contours of the upper surface 174 of the contact member 134 and the recesses of the back metal member 130 are circular. That is, the concave portion of the back metal member 130 has a mortar shape in which the diameter of the concave portion increases from the bottom surface 162 toward the upper surface 166, that is, a tapered shape, and the contact member 134 is a tapered member.

  Returning to FIG. 4, the concave portion of the back metal member 130 is formed by the tapered surface 160 and the bottom surface 162. The contact member 134 has a tapered surface 170 that contacts the tapered surface 160. The tapered surface 160 and the tapered surface 170 are formed at the pressing position of the piston 46. In a state where the tapered surface 160 and the tapered surface 170 are in contact, the bottom surface 172 of the contact member 134 does not contact the bottom surface 162 of the recess of the back metal member 130. The contact member 134 is fixed to the back metal member 130 by a spring 136 in a state where the tapered surface 160 and the tapered surface 170 are in contact with each other. Thus, by fixing the contact member 134, it is possible to prevent the contact member 134 from vibrating and hitting the back metal member 130 and the piston 146 while the vehicle is running and generating noise.

  In FIG. 4, the piston 46 and the disk rotor 26 are indicated by a two-dot chain line. During vehicle braking, the piston 46 presses the upper surface 174 of the contact member 134 in the direction of an arrow 80 parallel to a rotation axis (not shown) of the disk rotor 26. As a result, the tapered surface 170 of the contact member 134 is pressed against the tapered surface 160 of the backing member 130 by the pressing force of the piston 46. Here, the taper surface 160 and the taper surface 170 are formed at an angle with respect to the direction of the arrow 80 on which the pressing force acts. Accordingly, as in the case described with reference to FIG. 2, a component force of the pressing force in the direction of the arrow 80 on the tapered surface 160, that is, a force perpendicular to the tapered surface 160 and a force parallel to the tapered surface 160 are generated.

  Since the tapered surface 160 and the tapered surface 170 have a mortar shape, the force perpendicular to the tapered surface 160 in the back metal member 130 propagates radially from the tapered surface 160. In this way, the force that pushes the friction material 132 at an angle inside the back metal member 130 is widened, so that the difference due to the portion of the pad surface pressure is reduced. As a result, the brake squeal, brake vibration and friction during braking caused by the pressing force concentrated on the pressing position of the backing member 130 and the friction material 132, that is, near the center of the friction material 132 and the pad surface pressure becomes non-uniform. Uneven wear of the material 132 can be suppressed.

  Further, as described above, the bottom surface 172 of the contact member 134 does not contact the bottom surface 162 of the friction material 132 in the inner brake pad 133. Accordingly, as in the case of the inner brake pad 33 shown in FIG. 2, the pressing force applied by the piston 46 does not directly propagate from the bottom surface 172 of the contact member 134 to the bottom surface 162 of the friction material 132. Accordingly, since the pressing force is dispersed while avoiding being concentrated on the pressing position of the friction material 132, that is, near the center of the friction material 132, the difference due to the portion of the pad surface pressure can be reduced. As a result, the effect of suppressing the above-described brake squeal can be obtained better.

  Furthermore, the back metal member which concerns on the modification of this Embodiment is demonstrated. When the friction material is pressed against the disc rotor during vehicle braking, frictional heat is generated and the friction material expands. When the friction material expands, a force is also applied to the back metal member that supports the friction material in the direction in which the friction material expands greatly, for example, the longitudinal direction of the back metal member. When the coefficient of expansion of the friction material is higher than the coefficient of expansion of the back metal member, if the friction material expands, the friction material may be deformed so that the longitudinal end of the friction material warps toward the back metal member. As a result, at the time of vehicle braking, a portion near the center of the friction material is strongly pressed against the disc rotor, and the pressing force at the end in the longitudinal direction is weakened, resulting in brake squeal, brake vibration and vibration caused by uneven pad surface pressure. This can cause uneven wear of the friction material.

  FIG. 6 is a view of the backing member 230 according to the modification of the present embodiment as viewed from the direction in which the pressing force is applied. A plurality of slits 232 are formed in the back metal member 230 according to this modification at a position where a pressing force is applied by a piston (not shown). In the figure, the position pressed by the piston is indicated by a two-dot chain line. In order to avoid stress concentration at the tip when the slit 232 is opened and the back metal member 230 is broken, a small hole 234 is formed at the tip of each slit 232 as shown in FIG. The back metal member 230 supports a friction material (not shown) by sticking, for example, on a surface not shown in FIG.

  As shown in FIG. 6, the slits 232 formed in the back metal member 230 are formed in each of a plurality of straight lines parallel to the short direction of the back metal member 230. Here, as shown in the figure, the slits 232 are formed so as to be alternately cut from the lateral ends of the back metal member 230. Since the slits 232 are formed in the back metal member 230 in this way, each slit 232 spreads in the longitudinal direction when a longitudinal force is applied. Thereby, the back metal member 230 is deformed following the expansion of the friction material, so that it is possible to avoid deformation so that the longitudinal end of the friction material is warped toward the back metal member. As a result, the difference due to the portion of the pad surface pressure is reduced, and brake squeal, braking vibration and uneven wear of the friction material during braking can be suppressed.

  FIG. 7 is a view of a back metal member 330 according to a modified example different from the back metal member 230 shown in FIG. 6 as viewed from the direction in which the pressing force is applied. The back metal member 330 according to this modified example has a plurality of slits 332 formed at positions where a pressing force is applied by a piston, and a hole 334 for avoiding the back metal member 330 from being cracked at the tip of each slit 332. Is basically the same as the back metal member 230 shown in FIG. In FIG. 7, the position pressed by the piston is indicated by a two-dot chain line.

  The back metal member 330 is different from the slit 232 of the back metal member 230 shown in FIG. Each slit 332 is shorter than the slit 232, and a plurality of slits 332 are formed in each of a plurality of straight lines parallel to the lateral direction of the back metal member 330. Even with such a shape, the back metal member 330 is deformed following the expansion of the friction material during braking with the slits 332 extending in the longitudinal direction. Thereby, it can avoid deform | transforming so that the edge part of the longitudinal direction of a friction material may warp to the back metal member side. As a result, the difference due to the portion of the pad surface pressure is reduced, and brake squeal, braking vibration and uneven wear of the friction material during braking can be suppressed.

  The above-described back metal member 230 and back metal member 330 can also be applied to the brake disk device according to the present embodiment and its modifications. This makes it possible to better avoid uneven pad surface pressure, and increases the effect of suppressing brake noise during braking, brake vibration, and uneven wear of the friction material.

It is sectional drawing when the disc brake device which concerns on embodiment is cut | disconnected perpendicularly | vertically with a disc rotor. It is a figure which shows the inner brake pad in the AA cross section of FIG. It is the figure which looked at the inner brake pad from the upper surface side of the back metal member in the direction parallel to the rotation axis of the disc rotor. It is sectional drawing when the inner brake pad which concerns on the modification of embodiment is cut | disconnected perpendicularly to a disk rotor. It is the figure which looked at the inner brake pad which concerns on a modification in the direction parallel to the rotating shaft of a disk rotor from the upper surface side of a back metal member. It is the figure which looked at the back metal member which concerns on the modification of embodiment from the direction where pressing force is applied. It is the figure which looked at the back metal member which concerns on another modification different from the back metal member shown in FIG. 6 from the direction where pressing force is applied.

Explanation of symbols

  10 disc brake device, 16 caliper, 26 disc rotor, 30 backing metal member, 32 friction material, 33 inner brake pad, 34 contact member, 36 disc spring, 38 pin, 40 backing metal member, 42 friction material, 43 outer brake pad, 45 Piston seal, 46 Piston, 50 Press surface, 56 Claw part, 58 Cylinder part, 59 Storage part, 130 Back metal member, 132 Friction material, 133 Inner brake pad, 134 Contact member, 136 Spring, 230 Back metal member, 232 Slit, 330 Back metal member, 332 slit.

Claims (5)

A friction material disposed opposite to the friction sliding surface of the disk rotor rotating with the wheel;
A back metal member having a first surface that supports a surface of the friction material that does not face the disk rotor, and a second surface on which a slope is formed;
A contact member in contact with the slope formed on the second surface;
A pressing means that presses the contact member in a direction parallel to the rotation axis of the disk rotor and presses the friction material against a friction sliding surface of the disk rotor;
A disc brake device comprising:   The back metal member and the contact member are formed so that a front end surface of the contact member does not contact the back metal member when the contact member is in contact with the inclined surface formed on the second surface. The disc brake device according to claim 1. The slope formed on the second surface is provided to face substantially parallel,
The disc brake device according to claim 1, wherein the contact member has a surface in contact with an inclined surface provided to face the second surface. The slope formed on the second surface is a tapered surface,
The disc brake device according to claim 1, wherein the contact member is a tapered member having a surface in contact with a tapered surface formed on the second surface. A friction material disposed opposite to the friction sliding surface of the disk rotor rotating with the wheel;
A backing member that supports a surface of the friction material that does not face the disk rotor;
A pressing means that presses the backing member in a direction parallel to the rotation axis of the disk rotor and presses the friction material against the friction sliding surface of the disk rotor;
With
A disc brake device, wherein a slit is formed in a direction substantially parallel to the short direction of the back metal member in the vicinity of the position pressed by the pressing means in the back metal member.

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