JP2012121404A - Cylinder, and hydraulic system provided with the cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unpleasant feelings caused by abnormal noise and ensure silence in a cabin.SOLUTION: Pistons 4a and 4c slidably fit in a cylinder hole 42, and communication holes 20a and 21a making an inner peripheral side communicate with the outer peripheral side are formed at desired positions. When the communication holes 20a and 21a penetrate through a seal member 45 disposed at a desired position of the cylinder hole 42, hydraulic chambers 4b and 4d are demarcated in the cylinder hole 42. Furthermore, when the pistons 4a and 4c slide in an actuation-position direction, the inner pressures in the hydraulic chambers 4b and 4d are increased in the cylinder. The shapes of the communication holes 20a and 21a are formed to have the shapes of which opening areas are gradually increased when the pistons 4a and 4c return from actuation positions to non-actuation positions.

Description

  The present invention relates to a technical field of a brake or clutch cylinder in a vehicle such as an automobile, and a hydraulic system including the cylinder.

  2. Description of the Related Art Conventionally, in a hydraulic brake system or a hydraulic clutch system of an automobile, a master cylinder that generates a hydraulic pressure corresponding to a pedal force of a brake pedal or a clutch pedal is used to operate the brake device or the clutch device. As the master cylinder, a cylinder main body having a cylinder hole, a piston that slidably inserts the cylinder inner hole to define a hydraulic pressure chamber, a communication path that is provided in the cylinder main body and communicates with a reservoir tank, A communication hole formed in the piston and communicating with the communication passage and the hydraulic chamber, and is accommodated in a recess in the peripheral surface of the cylinder inner hole of the cylinder body, and the piston slidably penetrates, A master cylinder provided with a seal member that seals between a hole peripheral surface and the piston outer peripheral surface is known. The communication holes have a relatively small diameter and are arranged at a predetermined position and a predetermined interval of the piston. (For example, refer to Patent Document 1).

JP 2009-234491 A

In the cylinder described in Patent Document 1 and the hydraulic system including this cylinder, the following points are concerned.
When the brake pedal is depressed by the driver, the piston slides from the non-operating position to the operating position against the force of a return spring disposed in the hydraulic chamber of the master cylinder, and the communication hole As a result of passing through the seal member, a hydraulic pressure is generated in the hydraulic pressure chamber, the hydraulic pressure is transmitted to the brake device, and a braking force is generated on the vehicle.
Thereafter, when the driver releases the depression of the brake pedal, the piston tries to return from the operating position to the non-operating position by the force of the return spring. At this time, the hydraulic pressure chamber has a negative pressure, and immediately after the piston passes through the seal member and communicates with the inside of the reservoir tank through the communication hole, the hydraulic fluid in the reservoir tank passes through the communication hole. Through the fluid pressure chamber side.
At this time, the kinetic energy of the flow of the hydraulic fluid causes a sudden pressure rise in the hydraulic chamber, thereby generating a pressure wave (vibration), which is transmitted to the cylinder body, and this cylinder body is mounted. An abnormal sound (vibration sound) is transmitted to the inside of the bonnet or the cabin, and it is considered that the driver causes discomfort due to the abnormal sound and it is difficult to ensure quietness in the cabin.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cylinder capable of solving the above-described problems by preventing or suppressing the generation of the abnormal noise, and the cylinder. A hydraulic system is provided.

  In order to solve the above problems, the cylinder of the present invention is slidably inserted into the cylinder hole, and a communication hole is formed at the desired position to connect the inner peripheral side and the outer peripheral side. A piston that slides from the non-operating position to the operating position, and the piston receives the input, and the communication hole passes through a seal member that is disposed at a desired position of the cylinder hole. In the cylinder device in which the hydraulic chamber pressure is increased by receiving the input, the shape of the communication hole increases when the piston returns from the operating position to the non-operating position. It is characterized by being formed into a shape to make.

  Further, the cylinder of the present invention is characterized in that a plurality of the communication holes are formed, the arrangement is substantially equal, and the shape is substantially the same.

Furthermore, the hydraulic system of the present invention includes a reservoir tank that stores hydraulic fluid, a master cylinder that is supplied with hydraulic fluid in the reservoir tank and generates hydraulic fluid pressure during operation, and hydraulic pressure from the master cylinder. And the master cylinder is any one of the above-described cylinders of the present invention.

Furthermore, the hydraulic system according to the present invention is a brake system or a clutch system.

  According to the cylinder of the present invention configured as described above, the inside of the cylinder hole is slidably inserted, and the communication hole that connects the inner peripheral side and the outer peripheral side is formed at a desired position. A piston that slides from the operating position to the operating position, and the piston receives the input, and the communication hole passes through a seal member disposed at a desired position of the cylinder hole, so that a hydraulic chamber is formed in the cylinder hole. In the cylinder device that is partitioned and further receives the input, the hydraulic chamber pressure rises. When the piston returns from the operating position to the non-operating position, the opening area of the communicating hole increases for a while. It is molded into a shape. Therefore, immediately after the reservoir tank and the hydraulic chamber communicate with each other through the communication hole, the hydraulic fluid flowing into the hydraulic chamber from the reservoir tank gradually increases, Suppressing supply of hydraulic fluid at a stretch (the flow rate can be reduced). Thereby, generation | occurrence | production of abnormal noise can be prevented or suppressed, and the quietness in a cabin can be ensured or suppressed, without causing discomfort by the said abnormal noise.

Further, a plurality of the communication holes are formed, the arrangement is substantially equal, and the shape is substantially the same. Therefore, the above-mentioned effect can be obtained while the function of the communication hole is surely achieved.

  Further, according to the hydraulic system using the cylinder of the present invention, a reservoir tank that stores hydraulic fluid, a master cylinder that supplies hydraulic fluid in the reservoir tank and generates hydraulic fluid pressure during operation, At least an actuator that operates with hydraulic pressure from the master cylinder, and the master cylinder is any one of the above-described cylinders of the present invention, and can prevent or suppress the generation of abnormal noise. As a result, no uncomfortable feeling is caused, and the quietness in the cabin can be ensured or suppressed.

It is a figure showing typically a hydraulic system provided with an example of an embodiment of a cylinder concerning the present invention. It is sectional drawing of an example of embodiment of the cylinder concerning this invention. (A) is sectional drawing of the single body of the primary piston 4a described in FIG. 2, (b) is a fragmentary sectional view of (a). (A) is a partial cross-sectional view of the communication hole in the primary piston 4a of another example, and FIG. (B) is a partial cross-sectional view of the communication hole in the primary piston 4a of still another example.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a hydraulic system including an example of an embodiment of a cylinder according to the present invention.

As shown in FIG. 1, the hydraulic brake device 1 of this example is basically the same as a conventionally known two-system hydraulic brake device. That is, the hydraulic brake device 1 includes a brake pedal 2, a booster 3, a master cylinder 4, a reservoir tank 5, and a brake actuator 6. The reservoir tank 5 is attached to a master cylinder 4 fixed to the vehicle body. In this case, the reservoir tank 5 is attached so that the longitudinal direction thereof is the front-rear direction of the vehicle or substantially the front-rear direction of the vehicle.
Further, the reservoir tank 5 may be directly attached to the vehicle body and connected to the master cylinder 4 from the reservoir tank 5 by a hose or the like due to the structure of the vehicle or the layout.

Further, a fluid pressure control device 15 is interposed between the master cylinder 4 and the brake actuator 6, and between the master cylinder 4 and the fluid pressure control device 15, and between the fluid pressure control device 15 and the brake actuator 6. Are connected by respective brake pipes 16 and 17.

  When the driver depresses the brake pedal 2, the booster 3 is activated to boost and output the pedal effort with a predetermined servo ratio. The primary piston 4a of the master cylinder 4 is actuated by the output of the booster 3, and the hydraulic fluid in the primary hydraulic chamber 4b is supplied to the primary hydraulic pressure chamber 4b via the primary side output port 22, the brake pipe 16, the hydraulic pressure control device 15, and the brake pipe 17. While supplying to the brake actuator 6 of one system, the secondary piston 4c operates and the hydraulic fluid in the secondary hydraulic pressure chamber 4d is passed through the secondary side output port 23, the brake piping 16, the hydraulic pressure control device 15, and the brake piping 17. Then, the brake actuator 6 of one system is fed to the brake actuator 6 of the other system. When the loss stroke of each brake system disappears, the master cylinder 4 generates hydraulic pressure. The hydraulic pressure in the master cylinder 4 is transmitted to each brake actuator 6, and each brake actuator 6 generates a braking force so that each wheel 7 is braked.

  FIG. 2 is a cross-sectional view of an example of an embodiment of a cylinder according to the present invention. As shown in FIG. 2, the master cylinder 4 is a plunger-type master cylinder and includes a cylinder body 41. A cylinder hole 42 is formed in the cylinder body 41.

  In the cylinder hole 42, a primary piston 4a and a secondary piston 4c are slidably fitted. The primary piston 4a is slidable in the left-right direction in the figure by the brake pedal 2 or the brake booster 3 that boosts and outputs the brake pedal depression force. By the primary piston 4a and the secondary piston 4c, a primary hydraulic chamber 4b is defined between the primary piston 4a and the secondary piston 4c in the cylinder hole 42, and the secondary hydraulic chamber 4d is connected to the secondary piston 4c. A compartment is formed between the bottom 43 of the cylinder hole 42.

  A primary return spring mechanism 10 is provided in the primary hydraulic pressure chamber 4b. The first return spring mechanism 10 is wound around the first shaft member 8 and the outer periphery of the first shaft member 8. The coil-shaped first spring 13 includes a first retainer 30 and a second retainer 31 disposed on both sides of the first spring 13 in the axial direction. The left end portion of the first shaft member 8 in the drawing passes through the second retainer 31 and is always fixed to the primary piston 4a, and the right end portion of the first shaft member 8 in the drawing is inactivated by the primary piston 4a. When the primary piston 4a is in the operating state, the locking is released when the primary piston 4a is in the operating state.

Further, the secondary hydraulic pressure chamber 4d is provided with a second return spring mechanism 11, and the second return spring mechanism 11 includes a coiled second spring 14 that is contracted, and the second spring 14 that is The third retainer 32 is disposed on the inner periphery and has one end of the second spring 14 seated thereon, and the fourth retainer 33 is seated on the other end of the second spring 14.
The third retainer 32 and the fourth retainer 33 are fitted to each other, and the fourth retainer 44 is always in contact with the bottom 43 of the cylinder hole 42 and is fitted to the inside of the third retainer 32. Presents. When the secondary piston 4c is in an inoperative state, the third retainer 32 and the fourth retainer 33 maintain an engaged state, and when the secondary piston 4c is in an activated state, the engaged state is canceled. The
In the above description, it has been described that the first return spring mechanism 11 is provided in the primary hydraulic chamber 4b. However, the second return spring mechanism 12 may be provided in the primary hydraulic chamber 4b.

A reservoir tank 5 for storing brake fluid as hydraulic fluid is provided immediately above the cylinder body 41. The reservoir tank 5 can communicate with the primary hydraulic chamber 4b through the first communication path 20 and a first communication hole 20a formed in the primary piston 4a.
The first communication hole 20a is formed in the cylindrical portion 4e on the left end side in the figure of the primary piston 4a to communicate the primary hydraulic chamber 4b on the inner peripheral side of the primary piston 4a and the first communication passage 20 on the outer peripheral side. It is composed of radial holes. The reservoir tank 5 can communicate with the secondary hydraulic chamber 4d through the second communication passage 21 and a second communication hole 21a formed in the secondary piston 4c. Similar to the first communication hole 20a, the second communication hole 21a is also formed in the cylindrical portion 4f of the secondary piston 4c, and the secondary hydraulic chamber 4d on the inner peripheral side of the secondary piston 4c and the second communication path on the outer peripheral side. 21 is formed by a radial hole that communicates with 21.

  A recess 44 is formed at a desired location on the inner peripheral wall of the cylinder hole 42. A seal member 45 is disposed in the recess 44, and the first and second communication holes 20a and 21a are sealed. By passing through the member 45, the flow of the hydraulic fluid is blocked between the reservoir tank 5 and the primary hydraulic chamber 4a, and between the reservoir tank 5 and the secondary hydraulic chamber 4c, and further, the primary piston 4a and the secondary hydraulic chamber 4c. As the piston 4c moves to the left in the figure, the hydraulic pressure in the primary hydraulic chamber 4a and the secondary hydraulic chamber 4c increases.

  Then, by stopping the brake depressing operation by the driver, the primary piston 4a and the secondary piston 4c are returned to the non-operating position direction by the spring force of the first and second return springs 13 and 14.

Next, FIG. 3A is a cross-sectional view of a single primary piston 4a shown in FIG. As can be seen from this drawing, a plurality of first communication holes 20a are formed in the cylindrical portion 4e substantially equally in the radial direction, and the shape of each one is substantially the same. In the above description, the primary piston 4a has been described, but the second communication hole 21a is similarly formed in the secondary piston 4c.
3 (b) is an enlarged view of one of the first communication holes 20a described in FIG. 3 (a), so that the area of the first communication hole 20a increases toward the right side in the drawing. Molded.

  Specifically, FIG. 3B shows a triangle whose vertex is directed to the right side in FIG. With this structure, when the primary piston 4a tries to return from the operating position direction to the non-operating position direction by the spring force of the first spring 13 of the first return spring mechanism 10, the first communicating path 20 is first formed by the apex portion. And the first and second communication holes 20a communicate with each other, and the primary piston 4a moves toward the non-actuated position, so that the opening area of the first communication hole 20a is gradually increased.

This is because the internal pressure of the primary hydraulic pressure chamber 4a is negative immediately after the first communication hole 20a communicates with the first communication passage 20 and the reservoir tank 5 and the primary hydraulic pressure chamber 4a communicated with each other. Therefore, the opening area is reduced in order to prevent the hydraulic fluid in the reservoir tank 5 from flowing into the primary hydraulic pressure chamber 4a at a stroke due to the pressure difference, and the primary piston 4a further moves toward the non-actuated position. When returning to, it is possible to prevent the return delay of the primary piston 4a (prevent brake dragging).

  Next, FIG. 4A is a partial cross-sectional view of the communication hole in the primary piston 4a of another example, and FIG. 4B is a partial cross-sectional view of the communication hole in the primary piston 4a of still another example. . For convenience, FIGS. 4 (a) and 4 (b) will be described using other example communication holes in the primary piston, but the shape of this communication hole is also applicable to the secondary piston 4c. is there.

As can be seen from this figure, the shape of the first communication holes 120a and 220a is also the case where the primary piston 4a tries to return from the operating direction to the non-operating position direction by the spring force of the first spring 13 of the first return spring mechanism 10. First, the first communication holes 120a and 220a are connected to the first communication passage 20 at the narrower opening area, and the primary piston 4a is moved to the non-operation position, so that the first communication holes 120a and 220a are gradually moved. The opening area of the is increased.

Even in this case, as described above, the hydraulic fluid in the reservoir 5 is prevented from flowing into the primary hydraulic pressure chamber 4a at once due to the pressure difference between the primary hydraulic pressure chamber 4a and the reservoir 5, and the primary piston 4a When returning to the operation direction, it is possible to prevent the return delay of the primary piston 4a (prevention of brake dragging).

  In the cylinder of the present invention and the hydraulic system including the cylinder, a tandem master cylinder is used. However, the invention is not limited to this. For example, a single master cylinder may be used. Moreover, although the above-described embodiment for carrying out the present invention is an explanation using a brake system, the present invention is not limited to this and a clutch system may be used.

The cylinder according to the present invention can be suitably used for a plunger-type master cylinder that generates hydraulic pressure in the hydraulic pressure chamber when the piston moves forward and supplies hydraulic fluid to the hydraulic pressure chamber when the piston moves backward. In particular, it can be suitably used for a master cylinder of a brake or a clutch in a vehicle such as an automobile.
Moreover, the hydraulic system provided with this cylinder can be suitably used particularly for a brake system and a clutch system in a vehicle such as an automobile.

DESCRIPTION OF SYMBOLS 1 ... Hydraulic brake device, 2 ... Brake pedal, 3 ... Booster device, 4 ... Master cylinder, 4a ... Primary piston, 4b ... Primary hydraulic chamber, 4c ... Secondary repiston, 4d ... Secondary hydraulic chamber, 5 ... Reservoir tank, 6 ... Actuator, 7 ... Wheel, 13 ... First return spring, 14 ... Second return spring, 20 ... First communication path, 20a ... First communication hole, 21 ... Second communication path, 21a ... Second Communication hole 41 ... Cylinder body 42 ... Cylinder hole 43 ... Bottom part 44 ... Recess part 45 ... Seal member

Claims (4)

A piston that is slidably inserted into the cylinder hole and has a communication hole that connects the inner peripheral side and the outer peripheral side at a desired position. The piston slides from the non-operating position to the operating position in response to an input, and the piston. Receives the input, and the communication hole passes through a seal member disposed at a desired position of the cylinder hole, so that a hydraulic chamber is defined in the cylinder hole. In the cylinder where the pressure rises,
The cylinder is characterized in that the shape of the communication hole is formed such that the opening area of the piston increases for a while when the piston returns from the operating position to the non-operating position. 2. The cylinder according to claim 1, wherein a plurality of the communication holes are formed, the arrangement thereof is substantially equal, and the shapes thereof are substantially the same. A reservoir tank that stores hydraulic fluid; a master cylinder that supplies hydraulic fluid in the reservoir tank and generates hydraulic fluid pressure during operation; and an actuator that operates with hydraulic pressure from the master cylinder, and A hydraulic system, wherein the master cylinder is the cylinder according to claim 1 or 2. The hydraulic system according to claim 3, wherein the hydraulic system is a brake system or a clutch system.

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