JPH0953670A - Brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an opposed piston system by a single set of electric motor- driven system, by connecting first/second fluid chambers by a fluid path, and distributing pressing force, generated in the third piston provided in the third cylinder communicating with any of the first/second fluid chambers and the fluid path, to the first/second pistons. SOLUTION: First/second cylinders 31, 32 are provided to be opposed to a brake caliper 4, and first/second pistons 7, 8 are provided advanceably/ retreatably in the first/second cylinders 31, 32. A first fluid chamber 21 in a back surface side of the first piston 7 in the first cylinder 31 and a second fluid chamber 22 in a back surface side of the second piston 8 in the second cylinder 32 are connected by a fluid path 23, and a third cylinder 33, communicating with any of the first/second fluid chambers 21, 22 and the fluid path 23, is provided. A third piston 9, advanced/retreated by an electric motor 5, is provided in the third cylinder 33, and pressing force generated in the third piston 9 is distributed to the first/second pistons 7, 8.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a brake control device.

[0002]

2. Description of the Related Art The applicant of the present invention has previously proposed a brake device in which a brake is controlled by an electric motor.

This is a method in which a disk to be braked is pressed by a motor instead of the conventional hydraulic system. Numerical control is easy and electric wiring is required. It has the advantage that it can be installed and replaced. A specific structure is such that the rotating shaft of the motor is a rod, and the rod is screwed onto the piston to move the piston forward and backward in response to the rotation of the motor, thereby pressing the brake pad against the disc.

As described above, when the apparatus is operated by one motor, only one brake pad can be moved, so that the floating caliper method is inevitably adopted as the brake system. In this floating caliper system, the disk can be substantially crimped from both sides by making the caliper semi-fixed.

However, it goes without saying that the fixed caliper system, which can completely fix the caliper, is ideal in terms of accuracy. In this fixed caliper type, two independent sets of pistons are required, and the brake pads contacting the respective pistons sandwich the disc from both sides (opposing pistons). Therefore, the structure of the device becomes complicated and the cost becomes high.

[0006]

In order to realize such a fixed caliper (opposing piston) system by the above-mentioned electric system, two independent electric motors and peripheral mechanisms are required, and the power source is hydraulically operated. It is inevitable that the structural complexity will increase beyond the reliance on conventional hydraulic brakes. For this reason, there is a problem that the size and weight of the device are increased and the cost is increased.

The present invention has been made in view of the above-mentioned matters, and an opposed piston (fixed caliper) is provided by a set of electric drive systems.
It is a technical object to provide a brake control device capable of realizing the method. Further, it is a technical object to provide a brake control device in which the opposed piston type electric brake device can be configured to be lightweight, small-sized, and inexpensive.

[0008]

The present invention has the following configuration in order to solve the above technical problems. That is, in the brake caliper 4 having the first cylinder 31 and the second cylinder 32 that are provided opposite to each other, the first piston 7 that is provided in the first cylinder 31 so as to be movable back and forth,
The second piston 8 provided in the second cylinder 32 so as to be movable back and forth, and the first piston 7 in the first cylinder 31.
Liquid chamber 21 formed on the back side of the second cylinder 32, a second liquid chamber 22 formed on the back side of the second piston 8 in the second cylinder 32, and the first liquid chamber 21 and the second liquid chamber. A liquid passage 23 communicating with the first liquid chamber 21 and the second liquid chamber 2
The third cylinder 33 communicating with either the liquid passage 23 or the liquid passage 23.
And a third piston 9 provided in the third cylinder 33 and moved forward and backward by the electric motor 5, and configured to distribute the pressing force generated by the third piston 9 to the first piston 7 and the second piston 8. did.

Further, the first cylinder 31 and the third cylinder 33 are integrally provided on the same axis, and the first liquid chamber 2
1 may be formed by the back surface of the first piston 7 and the front surface of the third piston 9 in the first cylinder 31 and the third cylinder 33.

The brake caliper 4 is installed so that the disc 1 to be braked is located between the first piston 7 and the second piston 8.
The disk 1 is generally directly connected to the wheels of the vehicle, but is not necessarily limited to the brake for the vehicle in the present invention, and therefore is fixed to the rotating part of all industrial equipment. I am trying.

Each of the cylinders 31, 32 and 33 is formed in the caliper 4. The first cylinder 31 and the second cylinder 32 are generally arranged coaxially. Further, the third cylinder 33 may be formed at any position as long as it communicates with any of the first liquid chamber 21, the second liquid chamber 22, and the liquid passage 23. It is desirable that they are formed coaxially and integrally. When the first cylinder 31 and the third cylinder 33 are integrally provided, the cylinder inner diameters may be the same.

Further, the caliper 4 can be formed of metal die-cast or pressed steel plate which is less deformable. The electric motor 5 can be installed inside or outside the caliper 4.

The electric motor 5 is preferably a DC servo or a stepping motor, but in short, an AC motor, a linear motor or an ultrasonic motor can be used as long as it functions as an actuator.

One end of the first piston 7 is exposed outside the caliper 4 and presses the brake pad 11. Further, one end of the second piston 8 is exposed to the outside of the caliper 4 and presses the brake pad 12, and the disc 1 is positioned between the brake pads 11 and 12.

The torque generated by the electric motor 5 is directly or indirectly transmitted to the third piston 9 to move forward / backward. The fluid pressure is generated by the advance and retreat, and the first piston 7 and the second piston 8 are driven.

The first liquid chamber 21, the second liquid chamber 22,
The fluid passage 23 is filled with the hydraulic fluid (brake fluid) 10. In the present invention, it is possible to add a sensor for detecting the operation amount of the electric motor 5, specifically, a potentiometer or an optical sensor.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. The embodiment of the present invention applies the present invention to a vehicle disc brake. The caliper 4 is installed so as to straddle the disk 1 integrated with the wheel (not shown), and the first cylinder 31
And the second cylinder 32 are formed opposite to each other. Also,
The first cylinder 31 is formed integrally with the third cylinder 33 as a cylinder 34. The cylinder 34 is penetrated, and the electric motor 5 is attached to one end of the third cylinder 33 (one end of the cylinder 34). A DC servo is used for this electric motor 5, and a screw rod 5a is connected to its shaft.

The third cylinder 33 (the cylinder 34
The third piston 9 is fitted in one end side). The third piston 9 is formed into a hollow cylinder, and a hole 9b is provided at the center of one surface of the third piston 9. A thread having the same profile as that of the threaded rod 5a is formed on the inner surface of the perforated portion 9b, and both are threaded as shown in the drawing.

A first piston 7 is provided in the first cylinder 31 (the other end side of the cylinder 34) so as to be movable back and forth. The one end surface (back surface) of the first piston 7, the other end surface (front surface) of the third piston 9, and the cylinder 34
The first liquid chamber 21 is formed by the inner wall of the.

A part of the first piston 7 is exposed to the outside, and the exposed portion presses the brake pad 11. It should be noted that O-rings 9a and 7a are provided on the inner surface of the cylinder 34 so that the third piston 9 and the first piston 7 can be sealed respectively.

On the other hand, the second piston 8 is provided in the second cylinder 32 so as to be able to move back and forth. This second cylinder 3
In the inner part of 2, the rear surface of the second piston 8 and the second cylinder 3
A second liquid chamber 22 is formed by the inner wall of 2.
Further, like the first piston 7, a part of the second piston 8 is exposed to the outside, and the exposed portion presses the brake pad 12. Then, the disc 1 is located between the brake pad 11 and the brake pad 12. In addition, the O-ring 8 is also provided in the second cylinder 32.
a is provided, and the second piston 8 is sealed.

Further, the caliper 4 is provided with a liquid passage 23 having one end opening to the first liquid chamber 21 and the other end opening to the second liquid chamber 22. The inside of the first liquid chamber 21, the second liquid chamber 22 and the liquid passage 23 is filled with the brake fluid 10.

The operation of this apparatus will be described below. A predetermined voltage (or an AC signal or a pulse having a predetermined duty ratio) is applied to the electric motor 5 in accordance with the brake operation. As a result, the electric motor 5 rotates and the rod 5a rotates. With the rotation of the screw rod 5a, the third piston 9 moves forward to generate hydraulic pressure in the first liquid chamber 21. This hydraulic pressure is transmitted to the first piston 7 and simultaneously to the second piston 8 via the liquid passage 23 and the second liquid chamber 22, so that the pressure receiving areas of the first piston 7 and the second piston 8 are the same. Therefore, the pistons 7 and 8 move forward by the same pressure.

As a result, the disc 1 is sandwiched between the brake pads 11 and 12 and braked.
When the brake is released, the electric motor 5 is rotated in the reverse direction so that the pistons 7 and 8 are retracted.

As described above, since two pistons facing each other can be operated by one set of drive system (electric motor 5), a fixed caliper brake system can be realized easily and inexpensively.

[0026]

According to the present invention, an opposed piston type brake control device can be realized by a set of electric drive systems. Therefore, the fixed caliper brake control device can be constructed at low cost.

If the cylinder containing the piston driven by the electric motor is formed integrally with the cylinder containing any of the brake pistons, the device can be made more compact.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 ... disk 5 ... electric motor 5a ... screw rod 7 ... first piston 7a ... O ring 8 ... second piston 8a ... O ring 9 ... third piston 9a ... O ring 9b ... Part 10 Brake fluid 11 and 12 Brake pad 21 First liquid chamber 22 Second liquid chamber 23 Liquid passage 31 First cylinder 32 Second cylinder 33 Third cylinder 34 .. Cylinder (first cylinder and third cylinder)

Claims (2)

[Claims] 1. A first cylinder and a second cylinder which are provided to face each other.
In a brake caliper having a cylinder, a first piston provided to the first cylinder so as to be able to move forward and backward, a second piston provided to be able to move forward and backward at the second cylinder, and a rear side of the first piston in the first cylinder. A first liquid chamber formed and a second liquid chamber in the second cylinder.
The second liquid chamber formed on the back side of the piston and the first liquid chamber
A liquid passage that connects the liquid chamber and the second liquid chamber, a third cylinder that communicates with any one of the first liquid chamber, the second liquid chamber, and the liquid passage, and an electric motor that is provided in the third cylinder and moves back and forth. A brake control device, comprising: a third piston, wherein the pressing force generated by the third piston is distributed to the first piston and the second piston. 2. The first cylinder and the third cylinder are integrally provided on the same axis line, and the first liquid chamber is provided in the first cylinder and the third cylinder with a rear surface of the first piston and a third cylinder. The brake control device according to claim 1, wherein the brake control device is formed by the front surface of the piston.