JP4424234B2 - Disc brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk brake device capable of securing sufficient braking force also when thrust force of a brake pad with respect to a disk rotor is periodically fluctuated. <P>SOLUTION: When the thrust force of the brake pad 5 with respect to the disk rotor 2 is periodically fluctuated, applied pressure by piezoelectric elements 6A, 6B is set in accordance with braking requirement amount, and the brake pad 5 is pressurized at multiple points of which radial distances from a rotational center of the disk rotor 2 vary with each other. Therefore, sufficient braking force corresponding to the braking requirement amount is secured. At that time, applied force of the piezoelectric element arranged in the position of which radial distance from the the rotational center of the disk rotor 2 is long is set larger than that of the piezoelectric element arranged in the position of which radial distance is short, and is set much larger when the periodic fluctuation amount of the thrust force of the brake pad 5 is large, compared to the case where the periodic fluctuation amount is small. As a result, braking vibration can be securely suppressed, and sufficient braking force of which effective braking radius is large can be securely acquired. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a disc brake device equipped as a braking device in a vehicle, for example.

  In a disc brake device that obtains braking force by frictional contact between the brake pads against the outer peripheral side surface of the disc rotor, surface runout on the outer peripheral side surface due to thermal deformation of the disc rotor or uneven wear of the brake pad As a result, a so-called brake vibration or brake squeal phenomenon may occur.

Therefore, in order to solve such problems, the brake pad is composed of a plurality of pad pieces and each pad piece can be independently displaced so as to prevent uneven wear of the brake pads. A disc brake device that is uniformly pressed has been proposed (see, for example, Patent Document 1). In order to reduce brake vibration, a technique for controlling the pressing force of the brake pad in accordance with the variation in the thickness of the outer peripheral portion of the disc rotor has also been proposed (see, for example, Patent Document 2).
Japanese Utility Model Publication No. 62-114226 JP 2001-88669 A

  By the way, in the prior art described in patent document 1, since the several pad piece which comprises a brake pad is only comprised so that independent displacement is possible, when there exists a surface runout in the outer peripheral part side surface of a disc rotor. The pressing force of each pad piece may periodically fluctuate and brake vibration may occur.

  Therefore, an object of the present invention is to provide a disc brake device capable of ensuring a sufficient braking force while suppressing brake vibration even when the pressing force of the brake pad against the disc rotor periodically varies. .

The disc brake device according to the first aspect of the invention is provided between the caliper pressing portion that presses the brake pad toward the disc rotor and the brake pad, and the brake pad has a different radial distance from the rotation center of the disc rotor. A plurality of pressurizing means capable of pressurizing at a point position, a pressing force fluctuation amount detecting means for detecting a periodic fluctuation amount of the pressing force of the brake pad due to the surface vibration of the disk rotor, and the pressing force fluctuation amount detecting means. A pressing force setting means for setting the pressing force of the plurality of pressurizing means according to the braking request amount based on the detected cyclic fluctuation amount of the pressing force, and the pressing force setting means includes the pressing force fluctuation amount detecting means. In accordance with the increase in the amount of periodic fluctuation of the pressing force detected by the step, the pressing force of the pressing means arranged at a position where the radial distance from the rotation center of the disk rotor is long is set to be large. Characterized in that it is configured.

In the disc brake device according to the first aspect of the present invention, when the pressing force of the brake pad periodically fluctuates due to the surface vibration of the disc rotor , the pressurizing forces of the plurality of pressurizing means are determined according to the braking request amount based on the cyclic variation amount. Is set, and the plurality of pressurizing units pressurize the brake pads at multiple points at different radial distances from the rotation center of the disk rotor, so that a sufficient braking force according to the required braking amount is ensured. At that time, the pressurizing force of the pressurizing means arranged at a position where the radial distance from the rotation center of the disk rotor is long is set to increase according to the increase in the periodic fluctuation amount of the pressing force of the brake pad. And a sufficient braking force with a large effective braking radius is ensured.

Further, the disc brake device according to the second invention is provided between the caliper pressing portion that presses the brake pad toward the disc rotor and the brake pad, and the brake pad has a radial distance from the rotation center of the disc rotor. A plurality of pressurizing means (piezoelectric elements) capable of pressurizing at different multipoint positions, a pressing force fluctuation amount detecting means for detecting a periodic fluctuation amount of the pressing force of the brake pad, and the pressing force fluctuation amount detecting means A pressing force setting means for setting the pressing force of a plurality of pressurizing means according to the braking request amount based on the detected cyclic fluctuation amount of the pressing force, and the pressing force setting means detects the pressing force fluctuation amount. When the periodic fluctuation amount of the pressing force detected by the means exceeds a predetermined value, the pressure of the pressurizing means arranged at a position where the radial distance from the rotation center of the disk rotor is long is applied to the rotation of the disk rotor. Wherein the radial distance from the center is configured to set larger in comparison with the pressure of the deployed pressurizing means a short position.

In the disc brake device according to the second aspect of the present invention, when the pressing force of the brake pad periodically fluctuates due to the surface vibration of the disc rotor , the pressurizing forces of the plurality of pressurizing means are determined according to the braking request amount based on the cyclic variation amount. Is set, and the plurality of pressurizing units pressurize the brake pads at multiple points at different radial distances from the rotation center of the disk rotor, so that a sufficient braking force according to the required braking amount is ensured. When the periodic fluctuation amount of the pressing force of the brake pad exceeds a predetermined value, the applied pressure of the pressurizing means arranged at a position where the radial distance from the rotation center of the disk rotor is long becomes the radius from the rotation center of the disk rotor. Since the distance is set larger than the pressing force of the pressurizing means arranged at a short position, the brake vibration is reliably suppressed, and a sufficient braking force with a large braking effective radius is surely ensured.

According to the disc brake device according to the first aspect of the present invention, when the pressing force of the brake pad periodically fluctuates due to the surface vibration of the disc rotor , a plurality of pressurizing means are provided according to the braking request amount based on the cyclic variation amount. A pressing force is set, and a plurality of pressurizing means pressurize the brake pad at multiple points with different radial distances from the center of rotation of the disc rotor, so that a sufficient braking force according to the required braking amount can be secured. it can. At that time, the pressurizing force of the pressurizing means arranged at a position where the radial distance from the rotation center of the disk rotor is long is set to increase according to the increase in the periodic fluctuation amount of the pressing force of the brake pad. while suppressing, it is possible to secure a large enough braking force of the brake effective radius.

In the disc brake device according to the second aspect of the present invention, when the pressing force of the brake pad fluctuates periodically due to the surface vibration of the disc rotor , a plurality of pressurizations are performed according to the braking request amount based on the cyclic variation amount. The pressurizing force of the means is set, and a plurality of pressurizing means pressurize the brake pad at multiple points with different radial distances from the rotation center of the disk rotor, so that sufficient braking force according to the required braking amount is secured. be able to. When the periodic fluctuation amount of the pressing force of the brake pad exceeds a predetermined value, the applied pressure of the pressurizing means arranged at a position where the radial distance from the rotation center of the disk rotor is long becomes the radius from the rotation center of the disk rotor. Since the distance is set larger than the pressing force of the pressurizing means arranged at a short position, it is possible to reliably secure a sufficient braking force with a large braking effective radius while reliably suppressing the brake vibration. .

  Embodiments of a disc brake device according to the present invention will be described below with reference to the drawings. In the drawings to be referred to, FIG. 1 is a perspective view showing a schematic structure of a disc brake device according to an embodiment of the present invention, and FIG. 2 is a portion schematically showing a cross-sectional structure of a caliper portion of the disc brake device shown in FIG. FIG. 3 is a side view schematically showing the disc brake device shown in FIG.

  A disc brake device according to an embodiment is configured for a vehicle. For example, as shown in FIG. 1, a disc rotor 2 fixed to an axle hub 1 and integrally rotated, a suspension part of a vehicle body, and the like (not shown) ) And a torque member (mounting) 3 arranged so as to straddle the outer periphery of the disk rotor 2, and the outer periphery of the disk rotor 2 is mounted on the torque member 3 so as to be movable in the axial direction of the disk rotor 2. And a floating caliper 4 arranged so as to straddle the section. As shown in FIG. 2, a pair of brake pads 5 and 5 are arranged inside the caliper 4 so as to face both the inner and outer surfaces of the outer peripheral edge of the disc rotor 2.

  As shown in FIG. 2, the caliper 4 has a cylinder portion 4A facing the inner surface side of the disk rotor 2 and a pair of claw portions 4B and 4B facing the outer surface side of the disk rotor 2, and the cylinder portion 4A has a piston. 4C is inserted. The piston 4C is configured to advance and retreat in a direction orthogonal to the inner surface of the disc rotor 2 in accordance with brake hydraulic pressure supplied to the cylinder portion 4A via a brake pipe of a vehicle (not shown).

  Each brake pad 5 has a structure in which a pad member 5A is joined to a back metal 5B. In one brake pad 5, the pad member 5A faces the outer surface of the outer peripheral edge of the disk rotor 2, and the back metal 5B is a caliper 4. It faces the claw part 4B. In the other brake pad 5, the pad member 5 </ b> A faces the inner surface of the outer peripheral edge portion of the disk rotor 2, and the back metal 5 </ b> B faces the piston 4 </ b> C fitted into the cylinder portion 4 </ b> A of the caliper 4.

  As shown in FIG. 3, engagement protrusions 5C and 5C are formed at both ends of the back metal 5B of each brake pad 5. Correspondingly, a pair of locking grooves 3B, 3B for receiving and engaging the engaging protrusions 5C, 5C of the back metal 5B of each brake pad 5 with the arm portions 3A, 3A at both ends of the torque member 3, respectively. Is formed. The pair of locking grooves 3B and 3B are fitted with a predetermined clearance so that the engaging protrusions 5C and 5C of the back metal 5B of each brake pad 5 can be moved in the axial direction of the disc rotor 2, respectively. .

  When such a disc brake device advances the piston 4C of the caliper 4 shown in FIG. 2 and pushes the back metal 5B of the other brake pad 5 by the brake hydraulic pressure corresponding to the depression operation of the brake pedal of the vehicle, The claws 4B and 4B of the caliper 4 push the back metal 5B of one brake pad 5 by force, and the pad members 5A and 5A of the pair of brake pads 5 and 5 are both inner and outer surfaces of the outer peripheral edge of the disc rotor 1. Brake force is generated by frictional contact with

  Here, as shown in FIG. 2, the pressing portion of the caliper 4 that presses the brake pads 5, 5 toward the disc rotor 2, that is, the tip surface of the piston 4 </ b> C and the inner surface of the claw portion 4 </ b> B, A plurality of piezoelectric element groups 6A and 6B that can pressurize the brake pads 5 and 5 at multipoint positions with different radial distances from the rotation center are implanted as pressurizing means.

  As shown in FIG. 4, the piezoelectric element group 6 </ b> A includes, for example, eight piezoelectric elements 6 </ b> A <b> 1 to 6 </ b> A <b> 8 arranged along the circumferential direction of the tip surface of the piston 4 </ b> C. Here, the piezoelectric elements 6A1 to 6A3 are arranged at positions where the radial distance from the rotation center of the disk rotor 2 is long, and the piezoelectric elements 6A5 to 6A7 are arranged at positions where the radial distance from the rotation center of the disk rotor 2 is short. ing. The piezoelectric elements 6A4 and 6A8 are arranged at positions where the radial distance from the rotation center of the disk rotor 2 is medium.

  On the other hand, as shown in FIG. 5, the piezoelectric element group 6 </ b> B includes, for example, four piezoelectric elements 6 </ b> B <b> 1 to 6 </ b> B <b> 8 arranged on the inner surface of each claw portion 4 </ b> B of the caliper 4. Here, the piezoelectric elements 6B1 to 6B4 are arranged in a line at a position where the radial distance from the rotation center of the disk rotor 2 is long, and the piezoelectric elements 6B5 to 6B8 are positions where the radial distance from the rotation center of the disk rotor 2 is short. Are arranged in approximately one row.

  The driving of the piezoelectric element groups 6A and 6B as the pressurizing means is controlled by, for example, the control means 7 shown in FIG. The control means 7 is configured by using microcomputer hardware and software such as an ECU (Electric Control Unit) (not shown) mounted on the vehicle, and includes an input / output interface I / O, an A / D converter, A ROM (Read Only Memory) that stores programs and data, a RAM (Random Access Memory) that temporarily stores input data, and a CPU (Central Processing Unit) that executes programs are provided as hardware.

  Here, in the control means 7, a pressing force fluctuation amount detecting unit 7A as a pressing force fluctuation amount detecting means and a piezoelectric element driving signal setting unit 7B as a pressing force setting means are configured as software, and the piezoelectric element driving circuit. 7C is configured as hardware. Detection signals from the brake hydraulic pressure sensor 8 and the rotor rotation sensor 9 are input to the pressing force fluctuation amount detection unit 7A, and detection signals from the stroke sensor 10 are input to the piezoelectric element drive signal setting unit 7B. ing. A predetermined drive voltage is supplied from the piezoelectric element drive circuit 7C to the piezoelectric element groups 6A and 6B.

  The brake hydraulic pressure sensor 8 detects a brake hydraulic pressure supplied to the cylinder portion 4A of the caliper 4 via a brake pipe of a vehicle (not shown), and outputs a detection signal to the pressing force fluctuation amount detection portion 7A. Further, the rotor rotation sensor 9 detects the rotation of the disk rotor 2 shown in FIG. 1 and outputs a detection signal to the pressing force variation detecting unit 7A. Then, the stroke sensor 10 detects a depression stroke of a brake pedal of a vehicle (not shown) as a braking request amount, and outputs the detection signal to the piezoelectric element drive signal setting unit 7B.

  The pressing force fluctuation amount detecting unit 7A as the pressing force fluctuation amount detecting means calculates the fluctuation amount of the brake hydraulic pressure during one rotation of the disc rotor 2 based on the detection signals respectively input from the brake hydraulic pressure sensor 8 and the rotor rotation sensor 9. This is detected as a periodic variation amount of the pressing force of the brake pad 5, and the detection signal is output to the piezoelectric element drive signal setting unit 7B.

  The piezoelectric element drive signal setting unit 7B as the pressure setting means is a piezoelectric element group 6A as a pressure satisfying the required braking amount based on detection signals respectively input from the pressing force fluctuation amount detection unit 7A and the stroke sensor 10. , 6B are configured to set drive signals for the respective piezoelectric elements. In addition, when a drive signal is input from the piezoelectric element drive signal setting unit 7B, the piezoelectric element drive circuit 7C supplies a drive voltage corresponding to the level of the drive signal to each piezoelectric element constituting the piezoelectric element groups 6A and 6B. And these are inflated.

  Here, in the piezoelectric element drive signal setting unit 7B, the periodic fluctuation amount of the brake hydraulic pressure (periodic fluctuation amount of the pressing force of the brake pad 5) detected by the pressing force fluctuation amount detection unit 7A is a predetermined value (for example, 0. 1 MPa), the piezoelectric elements (piezoelectric elements 6A1 to 6A3 shown in FIG. 4 and the piezoelectric elements 6B1 to 6B4 shown in FIG. 5) disposed at positions where the radial distance from the rotation center of the disk rotor 2 is long. The drive signal is used as a drive signal for each piezoelectric element (piezoelectric elements 6A5 to 6A7 shown in FIG. 4 and piezoelectric elements 6B5 to 6B8 shown in FIG. 5) disposed at a position where the radial distance from the rotation center of the disk rotor 2 is short. It is configured to be set larger than that.

  At that time, when the piezoelectric element drive signal setting unit 7B is larger than when the periodic variation amount of the brake hydraulic pressure (periodic variation amount of the pressing force of the brake pad 5) detected by the pressing force variation detection unit 7A is small. Further, the drive signal of each piezoelectric element (piezoelectric elements 6A1 to 6A3 shown in FIG. 4 and piezoelectric elements 6B1 to 6B4 shown in FIG. 5) arranged at a position where the radial distance from the rotation center of the disk rotor 2 is long is further increased. Configured to set.

  In the disc brake device of the embodiment configured as described above, when a brake pedal (not shown) is depressed and braked while the vehicle is running, the brake hydraulic sensor 8 and the rotor rotation sensor 9 shown in FIG. Based on the input detection signals, the pressing force fluctuation amount detector 7 </ b> A detects the fluctuation amount of the brake hydraulic pressure during one rotation of the disc rotor 2 as the periodic fluctuation amount of the pressing force of the brake pad 5.

  Here, if there is a runout due to thermal deformation or the like on the side surface of the outer periphery of the disc rotor 2 that rotates together with the hub 1 of the axle, the pressing force of the brake pad 5 periodically fluctuates. When the brake hydraulic pressure detected by the sensor 8 periodically varies, the amount of periodic variation is detected by the pressing force variation detection unit 7A.

  Then, the piezoelectric element groups 6A and 6B are configured so that the piezoelectric element drive signal setting unit 7B has a value satisfying the required braking amount based on the detection signals respectively input from the pressing force fluctuation amount detection unit 7A and the stroke sensor 10. A drive signal for each piezoelectric element is set. Then, the piezoelectric element drive circuit 7C to which the drive signal is input supplies a drive voltage corresponding to the level of the drive signal to each piezoelectric element constituting the piezoelectric element groups 6A and 6B to expand them.

  As a result, the piezoelectric element group 6A implanted on the tip surface of the piston 4C shown in FIG. 2 and the piezoelectric element group 6B implanted on the inner surface of the claw portion 4B attach the back metal 5B of each brake pad 5 to the disk rotor 2. Pressurization is performed at multiple points with different radial distances from the center of rotation, thus ensuring a sufficient braking force according to the required braking amount.

  Here, when the periodic fluctuation amount of the brake hydraulic pressure detected by the pressing force fluctuation amount detection unit 7 </ b> A exceeds a predetermined value of, for example, 0.1 MPa, the piezoelectric element drive signal setting unit 7 </ b> B starts from the rotation center of the disk rotor 2. The drive signal of each piezoelectric element (piezoelectric elements 6A1 to 6A3 shown in FIG. 4 and piezoelectric elements 6B1 to 6B4 shown in FIG. 5) arranged at a position where the radial distance is long is used as the radial distance from the rotation center of the disk rotor 2. It is set larger than the drive signal of each piezoelectric element (piezoelectric elements 6A5 to 6A7 shown in FIG. 4 and piezoelectric elements 6B5 to 6B8 shown in FIG. 5) arranged at a short position. Therefore, in this case, a sufficient braking force with a large effective braking radius is ensured.

  Further, when the periodic fluctuation amount of the brake hydraulic pressure detected by the pressing force fluctuation amount detection unit 7A increases, the piezoelectric element drive signal setting unit 7B causes the piezoelectric elements 6A1 to 6A3 illustrated in FIG. 4 and the piezoelectric element illustrated in FIG. The drive signals for the elements 6B1 to 6B4 are set to be larger. Therefore, in this case, a sufficient braking force with a large braking effective radius and a larger applied pressure is ensured.

  Therefore, according to the disc brake device of one embodiment, even when the outer peripheral side surface of the disc rotor 2 has surface runout due to thermal deformation or the like and the pressing force of the brake pad 5 fluctuates periodically, the brake Sufficient braking force can be secured while reliably suppressing vibration.

  The disc brake device of the present invention is not limited to the above-described embodiment. For example, in the block diagram shown in FIG. 6, the brake hydraulic pressure sensor 8 that detects the brake hydraulic pressure as the pressing force of the brake pad 5 is changed to the piezoelectric element groups 6 </ b> A and 6 </ b> B that generate a voltage signal corresponding to the pressing force of the brake pad 5. May be.

  The hydraulically driven piston 4C built in the caliper 4 shown in FIG. 2 can be changed to a conventionally known electric piston. Further, the caliper 4 can be changed to a fixed structure in which pistons are arranged on both sides of the disk rotor 2.

  The disc brake device of the present invention can be applied not only for vehicles but also for braking rotating parts of various mechanical devices.

1 is a perspective view showing a schematic structure of a disc brake device according to an embodiment of the present invention. It is a fragmentary sectional view which shows typically the cross-section of the caliper part of the disc brake apparatus shown in FIG. FIG. 2 is a side view schematically showing the disc brake device shown in FIG. 1. It is a front view of the piston which shows the arrangement | positioning condition of the piezoelectric element attached to the piston of the caliper shown in FIG. 2 as a pressurizing means. FIG. 3 is a front view of the inner surface of the claw portion showing a state of arrangement of piezoelectric elements attached as pressure means to the claw portion of the caliper shown in FIG. It is a block diagram which shows the structure of the piezoelectric element drive control means which controls the drive of the piezoelectric element as a pressurization means shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub 2 Disc rotor 3 Torque member 3A Arm part 3B Locking groove 4 Caliper 4A Cylinder part 4B Claw part 4C Piston 5 Brake pad 5A Pad member 5B Back metal 5C Engagement protrusion 6A, 6B Piezoelectric element group (pressure means)
7 Control means 7A Pressure variation detection unit (Pressure variation detection means)
7B Piezoelectric element drive signal setting unit (pressure setting means)
7C Piezoelectric element drive circuit 8 Brake hydraulic pressure sensor 9 Rotor rotation sensor 10 Stroke sensor

Claims (3)

A plurality of calipers that press the brake pads toward the disc rotor are provided between the brake pads and the brake pads, and the brake pads can be pressed at multiple points with different radial distances from the rotation center of the disc rotor. A pressurizing means, a pressing force fluctuation amount detecting means for detecting a periodic fluctuation amount of the pressing force of the brake pad due to the surface vibration of the disk rotor, and a periodicity of the pressing force detected by the pressing force fluctuation amount detecting means. A pressurizing force setting unit that sets the pressurizing force of the plurality of pressurizing units according to a braking request amount based on a variation amount;
The pressurizing force setting means is a pressurization disposed at a position where the radial distance from the rotation center of the disk rotor is long in accordance with an increase in the periodic fluctuation amount of the pressing force detected by the pressing force fluctuation amount detecting means. A disc brake device characterized in that the pressing force of the means is set large. A plurality of calipers that press the brake pads toward the disc rotor are provided between the brake pads and the brake pads, and the brake pads can be pressed at multiple points with different radial distances from the rotation center of the disc rotor. A pressurizing means, a pressing force fluctuation amount detecting means for detecting a periodic fluctuation amount of the pressing force of the brake pad due to the surface vibration of the disk rotor, and a periodicity of the pressing force detected by the pressing force fluctuation amount detecting means. A pressurizing force setting unit that sets the pressurizing force of the plurality of pressurizing units according to a braking request amount based on a variation amount;
The pressing force setting means is disposed at a position where the radial distance from the rotation center of the disk rotor is long when the periodic fluctuation amount of the pressing force detected by the pressing force fluctuation amount detection means exceeds a predetermined value. A disc brake device characterized in that the pressing force of the pressing means is set larger than the pressing force of the pressing means arranged at a position where the radial distance from the rotation center of the disc rotor is short. . 3. The disc brake device according to claim 1, wherein the pressurizing means is constituted by a piezoelectric element.

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