JP3518021B2 - Vehicle braking system - Google Patents

Abstract

PURPOSE: To provide a vehicular brake device provided with a damper effective in restraining squeal of all oscillation frequencies. CONSTITUTION: A damper 7 for damping oscillation of an inner pad 2 is constituted of a weight 8, an elastic body 9, a displacement sensor 10 for detecting the moving amount of the weight 8, and a force generating means 11 composed of a magnet 11a and an electromagnet 11b, and the force corresponding to the output of the displacement sensor 10 of the weight 8 is changed into the direction to stop the movement of the weight 8 by the force generating means 11. Therefore, the apparent mass of the weight 8 changed, the resonance frequency of the weight agrees with the oscillation of any frequency, and the damper function is exhibited.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system for a vehicle, and more particularly to a brake system for damping vibration of a brake pad with a damper to suppress so-called squeal generated during braking. To improved braking systems. 2. Description of the Related Art A technique disclosed in Japanese Utility Model Laid-Open No. 2-101139 is an example of a technique for suppressing vibration of a brake pad by damping a vibration of a brake pad generated during vehicle braking. The damper disclosed in this publication is configured by attaching an elastic body with a weight to a free end to a brake pad or a brake piston to which vibration is transmitted from the pad, and the timing of the weight is caused by the vibration of the brake pad. It vibrates in a shifted state, whereby the vibration of the pad is attenuated and the squeal is suppressed. A conventional device of this type operates as a damper only for a vibration at a resonance frequency ω = √k / m determined by a spring constant k of an elastic body and a mass m of a weight. In addition, the vibration of the pad can be attenuated. That is, it is effective only for the squeal generated at the frequency of ω = √k / m. This is because k is a constant and the mass m of the weight is constant. [0004] However, in general, squealing occurs at a plurality of frequencies even with one brake, and therefore, in this type of conventional device which can cope with only one frequency,
There is a problem that the effect of suppressing the squeal becomes inadequate. [0005] It is an object of the present invention to solve such a problem and make it possible to deal with squeals of all frequencies. [0006] In order to solve the above-mentioned problems, according to the present invention, a brake device for a vehicle, which brakes the wheels by pressing a brake pad with an actuator against a rotor that rotates together with the wheels. A damper for attenuating vibration of the pad; an elastic body for attaching the damper to a brake pad or a member to which vibration is transmitted from the pad; a weight fixed to a free end side of the elastic body; and a movement amount of the weight. It comprises a displacement sensor to be detected, and a force generating means for applying a force corresponding to the output of the displacement sensor to the weight in a direction to hold down the weight. When the moving amount of the weight is Δ 移動 (the moving amount from the equilibrium point), the force F1 exerted on the weight by the elastic body is as follows: F1 = k1 * Δχ (k1 is a spring constant) (1) . Further, the force F2 exerted on the weight by the force generating means for generating a force corresponding to the output of the displacement sensor is expressed by F2 = k2 * Δχ (2). Here, k2 is a constant determined by the displacement detecting means. Therefore, if the mass of the weight is m, the resonance frequency ω of the weight is as follows: ω = √ (k1 + k2) / m (3) Here, k2 can be electrically adjusted, and the resonance frequency can be made variable by changing the apparent spring constant of the elastic body by the force F2 determined by this k2 and the movement amount Δχ of the weight. , To be able to respond to all squeals. FIG. 1 shows a first embodiment of the present invention. 1 in FIG.
Is a disk-shaped disk rotor (hereinafter simply referred to as a disk), which rotates together with the wheels of the vehicle. On both sides of the disk 1, an inner pad 2 and an outer pad 3 are supported so as to be able to narrow the disk. The support may be performed by the caliper 4 or by a torque member (not shown). The cylinder 6 of the caliper 4 has a built-in piston 5 for pressing the inner pad 2 in the axial direction of the disc and sliding the inner pad 2 against the disc 1. And the outer pad 3 is also pressed against the disk 1. Inside the piston 5, a damper 7 which characterizes the present invention is provided. This damper 7 has a weight 8
And a weight 8 is integrally fixed to the free end, and the other end is an elastic body 9 attached to the inner pad 2.
(The figure shows a leaf spring), a displacement sensor 10 for detecting the amount of movement of the weight 8 in the χ direction in the figure, a magnet 11a attached to the weight 8,
It comprises a force generating means 11 composed of two members, an electromagnet 11b attached to the inner surface of the piston 5 and facing the magnet 11a, and a control circuit 12 for controlling an exciting current of the electromagnet 11b. An output signal from the displacement sensor 10 is input to the control circuit 12, and based on the signal, the control circuit 12 controls the exciting current of the electromagnet 11b so as to satisfy the above equation (2). Accordingly, a force corresponding to the output of the displacement sensor 10, that is, the force F2 of the above-described equation (2) proportional to the amount of movement of the weight 8 in the χ-axis direction is applied to the weight 8. The direction of the force is such that the polarity of the magnet 11a or the output polarity of the control circuit 12 is such that the weight 8 is applied in the −χ direction when the weight 8 moves in the + χ direction, and is applied in the + χ direction when the weight 8 moves in the −χ direction. Therefore, the force acting on the weight 8 is increased by the force F2, and the resonance frequency of the weight 8 is obtained by the above-described equation (3). In this embodiment, as the displacement sensor 10, an optical displacement detector for obtaining displacement from a change in the intensity of reflected light or the like is used, but other principles such as a capacitance type and a magnetic type are applied. A displacement detector may be used. Further, the force generating means 11 is not limited to the one using the magnetic force shown. Other than this, for example, a device that applies a necessary force to the weight 8 using the force of static electricity can be used. FIG. 2 shows a specific example of the control circuit 12. The control circuit 12 arithmetically processes the output signal of the displacement sensor 10 so that a force proportional to the displacement amount Δ 量 of the weight 8 is applied to the weight 8 by the arithmetic processing circuit 13. Further, the frequency of the output signal of the displacement sensor 10 is converted into an electric signal by the F / V converter 15 and further passed through the arithmetic processing circuit 16 to obtain a gain adjustment signal. Then, the gain of the amplifying circuit 14 is adjusted {the k2 of the equations (2) and (3)} by the gain adjustment signal, and the coil current of the electromagnet 11b is controlled. The gain adjustment signal is processed by the arithmetic processing circuit 16 so that the resonance frequency of the weight 8 matches the frequency of the output signal of the displacement sensor 10. In this way, the frequency of the output signal of the displacement sensor 10 matches the vibration frequency of the inner pad 2, so that the resonance frequency of the weight 8 also matches the vibration frequency of the inner pad 2. The weight 8 works effectively as a damper for all vibration frequencies of the pad 2,
All squeals can be controlled. Although the output signal of the displacement sensor 10 is used as an input signal to the F / V converter 15, a vibration detecting means (piezoelectric element, acceleration sensor, etc.) for directly detecting the vibration of the inner pad 2 is used. ) May be added and the signal detected by the means may be input to the F / V converter 15. FIG. 3 shows a second embodiment of the present invention. In the present embodiment, the weight 8 is a magnetic material, and the magnetic attraction force of the electromagnet 11b is applied to the weight 8 of the magnetic material, so that the force F
2 is added. Other configurations and operations are almost the same as those of the first embodiment. In this configuration, the weight 8
Since only a pulling force in the −χ direction acts between the electromagnet 11b and the electromagnet 11b, a force in the + χ direction is applied to the movement of the weight 8 in the −χ direction. Direction force) is applied to the weight 8 in advance, and + χ
It is necessary to cover the force of F2 required in the direction by the elastic restoring force of the elastic body 9. FIG. 4 shows a third embodiment. In this embodiment,
As in the second embodiment, the weight 8 is made of a magnetic material, and an electromagnet 11b is provided on the opposite side with the weight 8 interposed therebetween.
The force in the direction is the attractive force of the upper electromagnet 11b in the figure, and
The force in the χ direction is generated by the attraction force of the lower electromagnet 11b in the figure. In this case, it is not necessary to apply the offset force required in the second embodiment. In this configuration, the control circuit 12 needs to control the two electromagnets so that when one is excited, the other is demagnetized. It is also conceivable to apply a current in which the forces are balanced to two electromagnets in advance so that the attraction force of the electromagnet to which the force of F2 is applied exceeds the attraction force of the other electromagnet. Also available. As described above, the braking device of the present invention can be used as a damper for damping the vibration of a brake pad.
A new spring has been developed, in which the apparent spring constant of the elastic body changes according to the output of the displacement sensor that detects the amount of movement of the weight, and the resonance frequency of the weight always matches the vibration frequency of the brake pad. Since the adoption is adopted, the effect of suppressing the squeal of all the frequencies appears, and it is possible to meet the demand for the further suppression of the squeal.

[Brief description of the drawings] FIG. 1 is a sectional view showing a first embodiment of a braking device according to the present invention. FIG. 2 is a diagram showing a specific example of a control circuit. FIG. 3 is a sectional view showing a main part of a second embodiment. FIG. 4 is a sectional view showing a main part of a third embodiment. [Explanation of symbols] 1 disk rotor 2 Inner pad 3 Outer pad 4 Caliper 5 piston 6 Cylinder section 7 Damper 8 Weight 9 Elastic body 10 Displacement sensor 11 Force generation means 11a magnet 11b electromagnet 12 Control circuit 13 Arithmetic processing circuit 14 Amplifier circuit 15 F / V converter 16 Arithmetic processing circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-117480 (JP, A) JP-A-1-169141 (JP, A) JP-A 8-128478 (JP, A) JP-A-2- 171371 (JP, A) Japanese Utility Model Showa 54-179376 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 49/00-71/04

Claims (1)

(1) A vehicle braking device for braking a wheel by pressing a brake pad with an actuator against a rotor that rotates with the wheel, the vehicle including a damper for damping vibration of the brake pad. An elastic body for attaching the damper to a brake pad or a member to which vibration is transmitted from the pad, a weight fixed to a free end of the elastic body, a displacement sensor for detecting a moving amount of the weight, and a displacement sensor for the displacement sensor. in addition to the direction in which detain the previous SL weight a force corresponding to the output frequency
And a force generating means for changing the resonance frequency of the weight .