JPH1182563A - Wet multiple disc brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously perform a brake and stop and prevent frictional vibration and squeak during braking by constructing each disc in such a manner that the relationship between the sliding velocity and the coefficient of friction between the discs is fixed or slightly increased at a fixed sliding velocity or more. SOLUTION: A wet multiple disc brake device X comprises a braking shaft 1, and a piston 3 for pressing a brake disc 2 for braking the braking shaft 1 and a disc 2 to each other. Each disc 2 is so constructed that the relationship between the sliding velocity and the coefficient of friction between the pressed discs 2 is fixed or slightly increased at a fixed sliding velocity or more. Thus, a hydraulic controlled piston 3 is slid to the brake disc 2 so that many discs 2 are pressed to each other with suitable pressing force by the piston 3. Accordingly, the braking force to the braking shaft 1 connected to the drive side can be controlled steplessly and also stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet-type multi-disc brake device capable of braking or stopping a drive side by pressing a plurality of disc plates against each other.

[0002]

2. Description of the Related Art Conventionally, there has been a brake such as a disc brake which brakes or stops by pressing a disc plate against a rotating rotating body as a means for braking the drive on the driving side.

[0003]

However, in a conventional disk brake as a brake, the rotating body can be stopped by controlling the braking by adjusting the force of pressing the disk plate against the rotating body. Continuous use is difficult due to frictional heat between the rotor and the rotating body, and frictional vibration during braking and squealing due to friction are likely to occur. There are also brakes that continuously brake, but these generally do not have the purpose of stopping.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and it is an object of the present invention to provide a wet-type multi-disc brake device capable of continuously braking and stopping to suppress frictional vibration and squeal during braking. It is in.

[0005]

In order to solve the above-mentioned problems, a wet-type multi-plate brake device according to the present invention comprises a braking shaft connected to a driving side and rotatably supported by a case main body; A plurality of disk plates alternately arranged on the braking shaft, and a piston slid by hydraulic pressure to press the disk plates against each other, wherein each disk plate has a sliding speed between the pressed disk plates and The relationship between the friction coefficients is such that the friction coefficient is constant or slightly increased at a certain sliding speed or higher. This allows the hydraulically controlled piston to slide on the disc brake plate and press the plurality of disc plates against each other with an appropriate pressing force by the piston, so that the braking force on the brake shaft connected to the drive side is increased. Can be controlled steplessly and stopped.

Further, the disk plates are pressed against each other, and the relationship between the sliding speed and the friction coefficient is configured so that the friction coefficient is constant or slightly increased at a certain sliding speed or higher. If the lubrication is performed sequentially, the wear of the disk plate can be extremely reduced, so that the braking can be continuously performed and the maintenance is not required.

Further, by controlling the hydraulic pressure of the piston, the braking of the control shaft (driving side) due to the pressure contact between the disc plates can be constantly maintained, and the braking can be performed accurately.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wet multiple disc brake device according to an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, a wet-type multi-disc brake device X (hereinafter simply referred to as “brake device X”)
A brake shaft 1, a multi-plate type brake disk plate 2 for braking the brake shaft 1, and a piston 3 for pressing the brake disk plate 2 are mainly constituted. Brake device X
Has a case body 7 composed of a front lid 5 and a bottom lid 6 that close both ends of a cylindrical case 4 by bolt connection. It protrudes. The brake shaft 1 is rotatably supported on each of the lids 5 and 6 via bearings 8 and 9. In addition, a cooling hole 10 is formed in the case body 1 at an interval in the axial direction inside the braking shaft 1, and the cooling hole 10 is formed through a through hole 11 of the bottom cover 6 through a pipe. It is connected to a hydraulic circuit (not shown) for supplying cooling oil. Reference numeral 12 denotes a tank, which is communicated with the inside of the case 4 to discharge the cooling oil.

The multi-plate type brake disk plate 2 is composed of a number of thin annular steel plates 15 and a plurality of friction plates 16 in which a friction material is bonded to a core of the thin annular steel plates. I have. The annular steel plates 15 and the friction plates 16 are located between the case 4 of the case body 1 and the braking shaft 1 and are alternately arranged in the axial direction of the braking shaft 1 as shown in FIG. Each steel plate 15 is fixed to the inner periphery of the case 2 and protrudes toward the brake shaft 1, and each friction material 16 is fixed to the outer cylindrical portion 18 of the double cylindrical member 17 integrated with the brake shaft 1. The cylindrical member 17 has a plurality of cooling oil holes 25 which are opened at the inner and outer circumferences of the outer cylindrical portion 18 and are located between the steel plates 15 and the friction plates 16. In addition, a plurality of communication holes 26 communicating with the front and rear sides of the case body 7 are formed in the torso portion 30. Also, each steel plate 15 and the friction plate 1
As shown in FIG. 3, the piston 6 can be freely pressed by the piston 3 at a predetermined interval.

The piston 3 is located on the bottom cover 6 side of the brake disc plate 2. As shown in FIG. 3, the piston 3 is provided with a sealing material (O
Ring) is slidable with a stepped hole 1
A pressure oil chamber a is defined between the pressure oil chamber 9 and the step portion 19a of the ninth, and is slid toward the brake disk plate 2 by control oil supplied to the pressure oil chamber a. The pressure oil chamber a is connected to a hydraulic circuit (not shown) by an introduction hole 20 formed in the case 4. The inside of the piston 3 has a plurality of pressing springs 21 arranged between the piston 3 and the bottom cover 6. This allows
The pressing force against each steel plate 15 and the friction plate 16 is adjusted by sliding the piston 3 against the pressing spring 21 by the control oil supplied from the hydraulic circuit to the pressure oil chamber a.

The friction material of the friction plate 16 is selected from the viewpoint of obtaining a high dynamic friction coefficient and a static friction coefficient close to the friction coefficient. For example, a filler material is added to a raw paper made of cellulose fiber or the like to be treated. A material which is rich in elasticity, circulated in the case body 7, and has excellent absorption of cooling oil and excellent friction characteristics, which has been developed for preventing vibration and squeal, is used. As described above, when the friction material of the friction plate 16 is selected, when the slip occurs while the steel plates 15 and the friction plate 16 are pressed against each other, as shown in FIG.
c) and the coefficient of friction (μ), generally the curves A and B
As the sliding speed (m / sec) increases, the friction coefficient (μ) decreases as shown by the curve C. After the sliding speed (m / sec) reaches a certain speed as shown by the curve C,
As the speed becomes higher, the friction coefficient (μ) becomes constant or rises little by little. Thereby, when braking the rotation of the prime mover (rotating body) connected to the braking shaft 1, even if each of the steel plates 15 of the disk plate 2 is pressed against the friction plate 16 and the disk plate 2 begins to slip, the frictional movement is prevented. Sliding speed (m / se
Regardless of the speeding-up of c), braking can be performed with a constant transmission torque (without reducing the transmission torque), and the slip becomes a positive resistance, thereby preventing the occurrence of frictional vibration and squeal due to friction. In curves A and B, in which the friction coefficient (μ) decreases as the sliding speed (m / sec) increases, the sliding becomes a negative resistance, the friction vibration is amplified, and the components constituting the brake device X are reduced. Resonates as a speaker and squeals due to friction. The friction plate 16 may be formed by adding an appropriate amount of tin powder, graphite powder, iron powder, or the like to a material mainly composed of copper powder, press-forming into a plate shape, and sintering the metal plate. ,
In short, with a high dynamic friction coefficient and a static friction coefficient close to the high dynamic friction coefficient, the slip velocity (m / s) as shown by the curve C in FIG.
Any material can be used as long as the relationship between ec) and the friction coefficient (μ) can be obtained.

Next, the operation of the wet multi-disc brake device X will be described with reference to FIG. The braking shaft 1 of the braking device X is
It is connected to the drive side composed of a motor (not shown),
The piston 3 is separated from the brake disc plate 2 against the pressing spring 21 by the control oil supplied to the pressure oil chamber a.

In this state, the control oil supplied to the pressure oil chamber a is discharged to the hydraulic circuit in order to brake the driving side including the prime mover and the like. The piston 3 is slid toward the brake disk plate 2 until the hydraulic pressure in the pressure oil chamber a and the spring force of the pressing spring 21 are balanced, and a pressing force obtained by subtracting the hydraulic pressure from the spring force of the pressing spring 21. To contact the steel plate 15 and the friction plate 16 with each other. Thereby, the brake shaft 1 (the prime mover) can be braked by an appropriate braking force by pressing the steel plates 15 of the brake disc plate 2 and the friction plates 16, and the steel plates 15 and the friction plates 16 slide when the braking is continued. To begin with, since there is a relationship between the sliding speed (m / sec) and the friction coefficient (μ) as shown in FIG. 4, there is no occurrence of squeal due to frictional vibration or friction with the transmission torque kept constant. In particular, each oil hole 1 of the cylindrical member 17
Since the cooling oil is lubricated between each steel plate 15 and the friction plate 16 from 8, the continuous braking is achieved without the occurrence of friction vibration and squeal.

Further, by adjusting the brake oil supplied to the pressure oil chamber a, the piston 3 is moved by the pressing force obtained by subtracting the oil pressure of the pressure oil chamber a from the spring force of the pressing spring 21 so that the disc brake plate 2 is pressed.
The steel plate 15 and the friction plate 16 can be pressed against the friction plate 16 with an appropriate pressing force by the piston 3 so that the braking force on the braking shaft 1 connected to the driving side of the motor or the like can be controlled steplessly. it can. Further, by discharging all the control oil supplied to the pressure oil chamber a to the hydraulic circuit, the piston 3 presses the steel plates 15 of the brake disk plate 2 and the friction material 16 by the spring force of the pressing spring 21. Then, the rotation of the brake shaft 1 is stopped. Therefore, the spring force of the pressing spring 21 needs to be sufficient to stop the rotation of the brake shaft 1 (drive side).

Further, each steel plate 15 of the brake disk plate 2 is pressed against the friction plate 16 so that the mutual sliding speed (m / sec) is obtained.
When the relationship between c) and the friction coefficient (μ) is as shown in FIG. 4 and the space between each steel plate 15 and the friction plate 16 is sequentially lubricated with cooling oil, the wear frequency of the friction material of the friction plate 16 is reduced. Since it can be reduced, braking can be performed continuously and there is no need for maintenance.

Furthermore, by controlling the piston 3 by hydraulic pressure, the braking of the control shaft 1 (drive side) by the pressure contact between the steel plates 15 of the brake disc plate 2 and the friction plates 16 can be constantly maintained at a high accuracy. It becomes possible.

In the wet multi-disc brake device X of the present invention, as a structure for applying a brake, the steel plate 15 and the friction plate 16 are pressed against each other by sliding the piston 3 by the spring force of the pressing spring 21. However, the present invention is not limited to this, and the steel plate 1 can be slid by sliding the piston 3 only by hydraulic control for supplying and discharging control oil without providing the pressing spring 21.
5 and the friction plate 16 may be configured to be pressed against each other.

[0019]

According to the wet multi-disc brake system of the present invention, each disk plate determines the relationship between the sliding speed and the friction coefficient between the disk plates so that the friction coefficient is constant or slightly higher than a certain sliding speed. Even if the piston controlled by the hydraulic pressure is slid toward the disk brake plate side and the plurality of disk plates are pressed against each other with an appropriate pressing force by the piston, the transmission is constant. Brake shaft (drive side) while preventing friction vibration and squeal due to friction with torque
Braking force can be continuously controlled and stopped.

Further, the disk plates are pressed against each other, and the relationship between the sliding speed and the friction coefficient is configured so that the friction coefficient is constant or slightly increased at a certain sliding speed or more, and the cooling oil is applied between the disk plates. If the lubrication is performed sequentially, the abrasion of the disk plate can be extremely reduced, so that it is possible to continuously brake and eliminate the necessity of maintenance, and it is possible to obtain a brake device having a long life.

Furthermore, by controlling the hydraulic pressure of the piston, the braking of the control shaft (drive side) due to the pressure contact between the disk plates is always kept constant, and it is possible to perform the braking with high accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a wet-type multi-plate brake device.

FIG. 2 is a sectional view showing a configuration of a wet-type multi-plate brake device.

FIG. 3 is an enlarged view of a main part of the wet multi-plate brake device shown in FIG.

FIG. 4 is a graph showing a relationship between a sliding speed and a friction coefficient between brake disc plates in a wet-type multi-disc brake device.

[Explanation of symbols]

 X Wet multi-plate brake device 1 Brake shaft 2 Brake disc plate 3 Piston 7 Case body 21 Press spring

Claims (2)

[Claims] A brake shaft connected to a driving side and rotatably supported by a case body; a plurality of disk plates alternately arranged on the case body and the brake shaft; A piston for pressing the disk plates against each other, wherein each of the disk plates has a relationship between a sliding speed and a friction coefficient between the pressed disk plates, and the friction coefficient is constant or slightly increased at a certain sliding speed or more. A wet-type multi-plate brake device characterized by being configured as described above. 2. The wet multi-disc brake device according to claim 1, wherein cooling oil is lubricated between the disc plates.