JPH0536096Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an opposed piston type disc brake device in which pistons are provided on both sides of a brake rotor.

BACKGROUND ART This type of opposed piston type disc brake device is, for example, an opposed type disc brake device disclosed in Fig. 4.38 on pages 190 and 191 of Automotive Engineering Zensho, Vol. 12, published by Sankaido (January 1982). Also known as a brake.

That is, in this opposed piston type disc brake device, as shown in FIG. 2, cylinders 3 and 3a are formed in a caliper 2 disposed straddling both sides of the brake rotor 1, respectively, and Pistons 5, 5a for pressing brake pads 4, 4a are housed in the cylinders 3, 3a.

Then, by supplying hydraulic pressure into the cylinders 3, 3a from a master cylinder (not shown), the pistons 5, 5a housed in the cylinders 3, 3a move the brake pads 4, 4a to the brake rotor 1.
Braking is performed by pressing against both sides of the brake.

The pair of cylinders 3, 3a are communicated with each other via a hydraulic pressure passage (not shown), and master cylinder hydraulic pressure is introduced into the cylinders 3, 3a from a hydraulic pressure inlet 6 provided in the caliper 2. When the brake is released, that is, when the brake pedal (not shown) is released, the hydraulic fluid is returned to the master cylinder from the hydraulic pressure inlet 6.

In the brake release state, the pistons 5, 5a are returned by a certain amount due to the deformation restoring force of the seals 7, 7a, and a predetermined clearance δ is provided between the brake rotor 1 and the brake pads 4, 4a. At this time, hydraulic fluid remains in the cylinders 3 and 3a.

Problems to be Solved by the Invention However, in such a conventional opposed piston type disc brake device, when the brake rotor 1 is installed inclined in the thickness direction, the brake rotor 1 rotates in a non-braking state. Then, one side of the pistons 5, 5a is pressed inward of the cylinders 3, 3a by the fallen portion of the brake rotor 1.

At this time, in the opposed piston type disc brake device, the caliper 2 is connected to the brake rotor 1.
Because it is fixed to the support member side (suspension side in the case of automobiles) that rotatably supports the
The piston 5 pressed by the brake rotor 1,
5a is pushed into the cylinders 3, 3a while discharging the hydraulic fluid from the hydraulic pressure inlet 6, thereby increasing the clearance δ.

However, once the pistons 5, 5a are pushed into the cylinders 3, 3a in this way, the amount of hydraulic fluid that has been pushed has been removed, so the pistons 5, 5a are not returned again, and the above-mentioned situation occurs. The increased clearance δ is maintained.

Therefore, in order to press the brake pads 4, 4a against the brake rotor 1 during subsequent braking, it is necessary to supply more hydraulic fluid in proportion to the increased clearance δ, resulting in a significant delay in braking timing. I had the problem of putting it away.

Therefore, in view of such conventional problems, the present invention is
Even if one piston is pushed into the cylinder,
It is an object of the present invention to provide an opposed piston type disc brake device capable of returning the piston to its original position when the pressing force of the piston is released and keeping the clearance between the brake rotor and the brake pad constant at all times.

Means for Solving the Problems In order to achieve the above object, the present invention comprises: a caliper disposed across both sides of a brake rotor and attached to a support member that rotatably supports the brake rotor; The brake pad includes brake pads arranged on both sides, cylinders formed on both sides of the brake rotor of the caliper and communicated with each other via a hydraulic passage, and a piston housed in the cylinder and capable of pressing the back side of the brake pad. By operating the brake operating member, the hydraulic pressure supplied from the master cylinder is supplied to the cylinder, so that the piston presses the brake pad, and the brake pad is pressed against the brake rotor, so that the brake is applied. In the opposed piston type disc brake device, a hydraulic pressure inlet for introducing the master cylinder hydraulic pressure into the cylinder is connected to a brake operation member that operates the master cylinder to open a hydraulic pressure introduction passage during braking and when not braking. It is constructed by providing a check valve that closes the hydraulic pressure introduction passage.

Operation With the above configuration, the opposed piston type disc brake device of the present invention is provided with a check valve that opens and closes in conjunction with the brake operation member at the hydraulic pressure inlet, so the check valve can be closed when braking is not being applied. This allows the hydraulic fluid to be contained within the caliper.

Then, the piston on one side is pressed by the inclined brake rotor, and the piston is forced into the cylinder and the hydraulic fluid removed from the cylinder is supplied to the other cylinder via the hydraulic passage. It is held within Calipa.

When braking, the check valve is closed and hydraulic fluid from the master cylinder is taken into the cylinder from the hydraulic pressure inlet, but when not braking, the required amount of hydraulic fluid is drawn into the caliper by closing the check valve. Since it is in the retained state, an extra amount of hydraulic fluid other than the preset amount is not required during braking, and delays in braking timing are prevented.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 1 shows an opposed piston type disc brake device 10 shown in a plan view as an embodiment of the present invention, and an example will be described in which the disc brake device 10 is used for braking a vehicle.

The disc brake device 10 includes a brake rotor 1 on a part of the outer circumference of the brake rotor 12.
A caliper 14 is provided which is disposed astride both sides of the brake rotor 12.
A pair of cylinders 16, 16a are formed on both sides of the cylinder.

The pair of cylinders 16, 16a are connected to each other via a hydraulic passage 18 formed in the caliper 14.

Pistons 20, 20a are slidably fitted into the cylinders 16, 16a, respectively, and by supplying hydraulic pressure into the cylinders 16, 16a, each piston 20, 20a moves toward the brake rotor 12. will be moved.

Further, a pair of brake pads 22, 22a are arranged on both sides of the brake rotor 12 between the pistons 20, 20a, and back metals 23, 23a of the brake pads 22, 22a are provided with a pair of brake pads 22, 22a.
The tip surfaces of each of the pistons 20, 20a are brought into contact with each other.

The brake pads 22, 22a are movably attached to a guide pin 24 attached to the caliper 14 so as to be oriented in the thickness direction of the brake rotor 12.
6 prevents the brake pads 22, 22a from rattling.

The caliper 14 is formed with a hydraulic pressure inlet 28 that communicates with one of the cylinders 16, and the hydraulic pressure supplied from the master cylinder 30 is introduced into the caliper 14 from the hydraulic pressure inlet 28. The hydraulic pressure introduced into the caliper 14 from the hydraulic pressure inlet 28 is transferred to the one cylinder 16.
and the other cylinder 16 via the hydraulic passage 18.
It is designed to be supplied to a.

The master cylinder 30 is operated by a brake pedal 32 as a braking operation member, and hydraulic pressure is generated in the master cylinder 30 by depressing the brake pedal 32.

Incidentally, the depression force of the brake pedal 32 is transmitted to the master cylinder 30 via a booster 34.

In this embodiment, the hydraulic pressure inlet 2
8 is provided with a solenoid valve 40 as a check valve.

The solenoid valve 40 is composed of an annular solenoid 42 and a valve body 44 inserted into the center of the solenoid 42. The valve body 44 is biased in the valve closing direction by a spring 46, and the solenoid The solenoid valve 40 is closed when the solenoid 42 is deenergized, and the solenoid valve 40 is opened when the solenoid 42 is energized.

Incidentally, the brake pedal 32 is normally provided with a stop lamp switch 50, so that the stop lamp is turned on when the brake pedal 32 is depressed to perform braking.

Therefore, the stop lamp switch 50 is activated when the brake pedal 32 is depressed.
ON, and OFF when the pedal is released,
The operating state of the brake pedal 32 is detected by the stop lamp switch 50.

Here, the output signal of the stop lamp switch 50 is output to the solenoid 42 of the solenoid valve 40, so that the solenoid 42 is energized and demagnetized.

That is, the stop lamp switch 50 is turned on.
When turned off, the solenoid 42 is energized, and when turned off, the solenoid 42 is demagnetized.

With the above configuration, in the opposed piston type disc brake device 10 of this embodiment, when the brake pedal 32 is depressed to brake the vehicle, the master cylinder 30 is actuated via the booster 34, and the master cylinder 30 is actuated via the booster 34. Hydraulic pressure is supplied from the cylinder 30 to the hydraulic pressure inlet 28 of the caliper 14 .

On the other hand, as the brake pedal 32 is depressed, the stop lamp switch 50 is turned on, and the ON signal from the stop lamp switch 50 energizes the solenoid 42 of the solenoid valve 40, so that the solenoid valve 40 is opened.

Then, the hydraulic pressure of the master cylinder 30 is
Through the opened solenoid valve 40,
Cylinder 1 in the caliper 14 from the hydraulic pressure inlet 28
6, 16a, and the piston 20,
20a is pressed to bring the brake pads 22, 22a into pressure contact with the brake rotor 12.

Then, when the brake pedal 32 is released from the brake pedal 32 to release the brake, the generation of hydraulic pressure in the master cylinder 30 is stopped, and the stop lamp switch 50 is turned OFF by releasing the brake pedal 32 from the depression. Therefore, the solenoid 42 is demagnetized and the solenoid valve 40
By closing the valve, the hydraulic pressure inlet 28 is shut off.

Then, the hydraulic fluid is sealed in the caliper 14, and the pair of cylinders 16, 1
6a and the hydraulic passage 18 are filled with a certain amount of hydraulic fluid.

Therefore, when the brake rotor 12 is inclined with respect to the central axis, the inclined portion of the rotating brake rotor 12 causes one of the pistons 20 or 20a to be moved into one of the cylinders 16 in which the piston is housed. or pressed inward of 16a,
A so-called knockback phenomenon occurs.

Then, the piston 20 or 20 that received the pressing force
a is forced into its cylinder 16 or 16a and displaces hydraulic fluid from said cylinder 16 or 16a, which displaced hydraulic fluid is then transferred to the hydraulic passage 18.
It is supplied to the other cylinder 16a or 16 via the cylinder 16a or 16, and is stored in the cylinder 16a or 16.

At this time, the other cylinder 16a or 16
The inner piston 20a or 20 tries to be ejected, but since the brake rotor 12 is tilted in the opposite direction, the movement of said piston 20a or 20 is possible, and the operation eliminated in one cylinder 16 or 16a All of the liquid is stored in the other cylinder 16a or 16.

Therefore, when braking the vehicle next time, the solenoid valve 40 opens as described above and the hydraulic pressure of the master cylinder 30 is supplied to the caliper 14, but the hydraulic fluid in the caliper 14 is Since a constant amount of fluid is maintained even due to the knockback phenomenon, the amount of fluid required for braking will not increase beyond a preset amount, and therefore the amount of depression of the brake pedal 32 will be reduced. This does not increase the number of times, and delays in braking timing are prevented.

In addition, in the above-mentioned configuration, since there is a time lag until the residual pressure in the caliper 14 is released when the brake is released, when the brake pedal 32 is suddenly returned, the stop lamp switch 50 is turned off. By setting the solenoid 42 of the solenoid valve 40 to be demagnetized after the above time difference, the above residual pressure can be eliminated and a predetermined clearance is provided between the brake pads 22, 22a and the brake rotor 12. be able to.

Further, although a solenoid valve 40 is provided as a check valve provided in the hydraulic pressure inlet 28, it is not limited to the solenoid valve 40, and means for opening and closing the hydraulic pressure inlet 28, for example, a pin insertion type. A solenoid valve may also be used.

Furthermore, in this embodiment, a case is shown in which a pair of opposed pistons 20 and 20a are provided; however,
It goes without saying that the present invention can be applied even if two or more pairs of opposed pistons are provided.

Effects of the Invention As explained above, in the opposed piston type disc brake device of the present invention, a check valve is provided at the hydraulic pressure inlet for introducing master cylinder hydraulic pressure into the cylinder provided in the caliper, and the check valve is used to control the braking. Since the check valve is opened and closed in conjunction with the operating member, by closing the check valve when the brake is released, the hydraulic fluid is contained within the caliper, and even when the piston moves due to knockback, a certain amount of fluid remains inside the caliper. Can hold hydraulic fluid.

Therefore, the amount of hydraulic fluid supplied to the caliper during the next braking will not be increased beyond a predetermined constant amount, and this provides an excellent effect of preventing delays in braking timing. play.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional side view of a conventional opposed-piston type disc brake device. DESCRIPTION OF SYMBOLS 10... Opposed piston type disc brake device, 12... Brake rotor, 14... Caliper, 16, 16a... Cylinder, 18... Hydraulic pressure passage, 20, 20a... Piston, 22, 22a...
...Brake pad, 28...Hydraulic pressure inlet, 30...
... Master cylinder, 32 ... Brake pedal (braking operation member), 40 ... Solenoid valve (check valve), 50 ... Stop lamp switch.

Claims (1)

[Scope of Claim for Utility Model Registration] A caliper disposed astride both sides of a brake rotor and attached to a support member that rotatably supports the brake rotor; brake pads disposed on both sides of the brake rotor; and the caliper. cylinders formed on both sides of the brake rotor and communicated with each other via hydraulic passages, and a piston housed within the cylinder that can press the back side of the brake pad, and by operating a brake operating member, In an opposed piston type disc brake device in which the hydraulic pressure supplied from the master cylinder is supplied to the cylinder, the piston presses the brake pad, and the brake pad is then brought into pressure contact with the brake rotor to perform braking, A check valve is installed at the hydraulic pressure inlet port for introducing the master cylinder hydraulic pressure into the cylinder, and in conjunction with the brake operation member that operates the master cylinder, opens the hydraulic pressure introduction passage during braking, and closes the hydraulic pressure introduction passage when not braking. An opposed piston type disc brake device characterized by being provided with.