KR20100030463A - Master cylinder - Google Patents

Abstract

PURPOSE: A master cylinder is provided to minimize brake releasing delay by connecting a through-hole and a flow path of an oil tank. CONSTITUTION: A master cylinder comprises a cylinder main body(20), a piston(30), and a sealing member. The cylinder main body comprises an oil inflow hole(25) and a liquid pressure chamber(23). The piston comprises through-holes which connects an oil inflow hole and a liquid pressure chamber and increases the pressure of the inside of the liquid pressure chamber. The sealing member is formed between the cylinder main body and the piston and selectively blocks the circulation of the oil through the through-hole of the piston.

Description

Master Cylinder {MASTER CYLINDER}

The present invention relates to a master cylinder, and more particularly, to a master cylinder in which the communication port of the piston and the oil passage on the oil tank side are quickly communicated.

The master cylinder is a device for generating hydraulic pressure in the hydraulic brake system. 1 exemplarily illustrates a general tandem master cylinder and an oil tank applied to a vehicle.

As shown in FIG. 1, the master cylinder includes a cylinder body 1 and a first piston 3 and a second piston 4 which are installed to be retractable in the bore 2 of the cylinder body 1. do.

The first piston 3 and the second piston 4 face the first hydraulic chamber 7 and the second hydraulic chamber 8 through the first and second oil inlets 6 communicating with the oil tank 5. It is provided with a plurality of communication ports (9) for allowing oil to flow in, respectively.

When the first piston 3 and the second piston 4 are advanced, communication between the first and second oil inlets 6 and the plurality of communication ports 9 is blocked by the sealing members 11. The hydraulic pressures of the first hydraulic chamber 7 and the second hydraulic chamber 8 rise.

On the contrary, when the first piston 3 and the second piston 4 retreat, the plurality of communication ports 9 are moved to the rear of the sealing members 11, respectively, so that the first and second oil inlets 5 and 6 In communication with. Accordingly, the oil in the first hydraulic chamber 7 and the second hydraulic chamber 8 returns to the oil tank 5, and the hydraulic pressure in the first hydraulic chamber 7 and the second hydraulic chamber 8 drops. , The braking pressure is released.

As shown in Figure 2a, the sealing member 11 is provided in a ring shape and is installed in the receiving groove (1a) of the cylinder body (1). The sealing member 11 is also called a cup chamber because it has an inner blade portion 11a in contact with the outer surface of the piston 4 and an outer wing portion 11b in contact with the inner surface of the receiving groove 1a and has a cup-shaped cross-sectional structure. .

As shown in FIG. 2B, since the pressure of the hydraulic chamber 8 acts on the inner surface of the sealing member 11 when the piston 4 moves forward, the inner blade portion 11a and the outer blade portion 11b are pistons. (4) The pressure of the hydraulic chamber 8 is increased by being in close contact with the outer surface and the inner surface of the receiving groove 1a to block the flow of oil. As the pressure in the hydraulic chamber 8 rises, the deformation of the inner and outer blade portions 11a and 11b also increases, and the adhesion force also increases.

However, as shown in FIG. 2C, even when the piston 4 is retracted, the deformation state of the sealing member 11 is maintained by the hydraulic pressure so that the inner blade portion 11a blocks the communication port 9 to return the oil. It happens when you block it. Accordingly, there is a problem that the piston (3) causes the operation (Lost travel) to retreat irrelevantly a predetermined section, and delay the release of braking. This phenomenon is exacerbated when the temperature of the oil rises in the summer and the pressure in the hydraulic chamber 8 increases.

The present invention is to solve such a problem, an object of the present invention is to provide a communication between the communication port of the piston and the oil tank side when the brake is quickly communicated to the master to minimize the meaningless retraction and braking release delay of the piston To provide a cylinder.

The master cylinder according to the present invention for achieving this object has a cylinder body having an oil inlet and a hydraulic chamber; and a plurality of communication ports for communicating the oil inlet and the hydraulic chamber, in the bore of the cylinder body. And a piston for advancing and elevating the pressure in the hydraulic chamber; and a sealing member provided between the cylinder body and the piston to selectively block the flow of oil through the communication port of the piston. When the pressure is released, the pressure in the hydraulic chamber is preliminarily discharged through at least one of the plurality of communication ports.

In this case, at least one communication port of the plurality of communication ports may be in communication with the oil inlet before other communication holes.

In addition, the diameter of the inlet of the at least one communication port of the plurality of communication ports may be formed larger than the other communication ports.

In addition, the inlet of the one or more communication ports of the plurality of communication ports may have an extension extending toward the rear of the piston.

In addition, the extension may be made in the form of a slit.

In addition, the center of the inlet of the at least one communication port of the plurality of communication ports may be formed behind the piston than the center of the inlet of the other communication ports.

In the master cylinder according to the present invention, since the pressure of the hydraulic chamber is preliminarily discharged through one or more communication ports of the plurality of communication ports at the time of brake release, it is easy to open the communication port by relieving the adhesive force between the sealing member and the piston. By doing so, there is an effect that the braking is released quickly.

Accordingly, the meaningless retraction of the piston and the brake release delay are minimized.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

3 is a cross-sectional view showing a master cylinder according to the first embodiment of the present invention, Figures 4a and 4b is a view showing the cylinder body and the piston during retraction according to the first embodiment of the present invention. 4B is an enlarged cross-sectional view of B of FIG. 3.

As shown in FIG. 3, the master cylinder has a cylinder body 20 having a bore 21 formed therein, and a first piston 30 installed in the bore 21 of the cylinder body 20 so as to be retractable. And a second piston 40.

A sealing member 50 is provided between the inner circumferential surface of the bore 21 of the cylinder body 20 and the outer circumferential surfaces of the pistons 30 and 40 to prevent leakage of oil and to form a high pressure hydraulic pressure.

The first sealing member 51 and the second sealing member 52 are provided between the inner surface of the bore 21 and the outer surface of the first piston 30, respectively, and the inner surface of the bore 21 and the second piston 40 are provided. Between the outer surface of the third sealing member 53 and the fourth sealing member 54 are respectively installed. Each of the sealing members 51, 52, 53, 54 is installed in the receiving grooves 22 formed on the inner surface of the bore 21 so that the pistons 30, 40 do not move even when the pistons 30, 40 move forward and backward. In this case, the second sealing member 52 and the fourth sealing member 54 may be formed of oil through the communication holes 100 and 100 ′ which will be described later according to the advancing and retracting operations of the first piston 30 and the second piston 40. The flow is selectively blocked, whereby the hydraulic pressure of the first hydraulic chamber 23 and the second hydraulic chamber 24 rises.

The cylinder body 20 is formed between the first hydraulic chamber 23 formed between the first piston 30 and the second piston 40, and the inner end surfaces of the second piston 40 and the bore 21. The second hydraulic chamber 24 is provided.

In addition, when the first hydraulic chamber 23 and the second hydraulic chamber 24 are pressurized by the first piston 30 and the second piston 40 to the cylinder body 20, the first hydraulic chamber 23 and The first oil outlet 25 is formed at the first hydraulic chamber 23 side so that the oil in the second hydraulic chamber 24 can be discharged, and the second oil outlet 26 is formed at the second hydraulic chamber 24 side. do. The oil of the first hydraulic chamber 23 and the second hydraulic chamber 24 is discharged to the first oil outlet 25 and the second oil outlet 26 and supplied to a wheel cylinder (not shown) on the wheel side.

In addition, the cylinder body 20 includes a first oil inlet 27 and a second oil inlet 28, and the first oil inlet 27 and the second oil inlet 28 are upper portions of the cylinder body 20. It is connected to the oil tank 60 provided in.

The first piston 30 and the second piston 40 are connected in series at a predetermined distance, and retreat inside the bore 21 of the cylinder body 20, and the first hydraulic chamber 23 and the second hydraulic chamber Raise the pressure of (24).

The first piston 30 and the second piston 40 have a first restoring spring 71 and a second restoring spring 72 for restoring the first piston 30 and the second piston 40 after the braking operation ends. Each of the spring receiving grooves 31 and 41 is provided.

At this time, each of the spring receiving grooves 31 and 41 of the first piston 30 and the second piston 40 is provided with support portions 32 and 42, and each of the support portions 32 and 42 has a first restoration spring 71. ) And retainers 33 and 43 for supporting the second restoring spring 72 on one side are fitted to be retractable. Reference numerals 35 and 45 denote steppings fitted to the support parts 32 and 42 to prevent the retainers 33 and 43 from being separated. As a result, one end of the first restoring spring 71 and the second restoring spring 72 is supported inside the spring receiving grooves 31 and 41, and the other end thereof is flanged end 34 of each retainer 33 or 43. 44).

In addition, the first piston 30 further includes a plurality of communication ports 100 for communicating the first hydraulic chamber 23 and the first oil inlet 27, and the second piston 40 includes the second hydraulic chamber. A plurality of communication ports (100 ') for communicating the 24 and the second oil inlet 28 is further provided. Hereinafter, the communication port according to the present embodiment will be described by taking the first piston 30 as an example, and the following description may be applied to the second piston 40 unless otherwise specified.

As shown in FIGS. 4A and 4B, the inlet 111 of the one or more communication ports 110 of the plurality of communication holes 100 extends toward the rear of the first piston 30. 112 is provided. At this time, the extension 112 may be formed by cutting one side of the communication port 110.

As shown in FIG. 4B, when the retracting operation of the piston 30 starts, the communication port 110 having the extension 112 communicates with the first oil inlet 27 before the other communication ports 120. As a result, a small amount of oil in the first hydraulic chamber 23 flows out through the extension 112 of the communication port 110 to the first oil inlet 27, and then a large amount of oil passes through the communication port 100. Spills. In other words, some of the communication ports 110 of the communication ports 100 closed by the sealing member 52 are first opened through the extension part 112, whereby the hydraulic pressure of the first hydraulic chamber 23 is increased. It is discharged preliminarily.

Therefore, in the master cylinder of the present embodiment, since the pressure in the hydraulic chamber is preliminarily released through some of the communication ports of the plurality of communication ports, the pressure between the sealing member and the piston is eased to facilitate opening of the communication holes, thereby providing braking. There is an effect that the release is made quickly.

In addition, the extension of the present embodiment can be formed by cutting the conventional communication port, there is an advantage that the processing is easy.

The following describes the overall operation of such a master cylinder.

5 is a cross-sectional view showing a master cylinder according to the first embodiment of the present invention, showing a state in which the piston is pressed. As illustrated in FIG. 5, when the first piston 30 is pressurized by the braking operation, the first hydraulic pressure chamber 23 is pressed while the first piston 30 moves forward, and the first hydraulic pressure chamber 23 is pressed. When pressurized, the second piston 40 is advanced by the pressure of the first restoring spring 71 and the first hydraulic pressure chamber 23, and accordingly, the second hydraulic pressure chamber 24 is pressurized. At this time, the second sealing member 52 and the fourth sealing member 54 block the communication between the first and second hydraulic chambers 23 and 24 and the first and second oil inlets 27 and 28. The pressure of the 1st hydraulic chamber 23 and the 2nd hydraulic chamber 24 rises. The oil in the first hydraulic chamber 23 and the second hydraulic chamber 24 is supplied to a wheel cylinder (not shown) on the wheel side through the first oil outlet 25 and the second oil outlet 26. Braking takes place.

When the brake is released (see FIGS. 3, 4A, and 4B), the first piston 30 and the second piston 40 are rearward due to the elasticity of the first restoring spring 71 and the second restoring spring 72. Since the first piston 30 and the second piston 40 are returned to their original positions. At this time, a small amount of oil in the first and second hydraulic chambers 23 and 24 starts to flow out first through the extension 112 of the communication port 110, and the hydraulic pressure in each of the hydraulic chambers 23 and 24 is preliminarily. As the retracting operation of the first piston 30 and the second piston 40 proceeds, the first and second communication ports 100 and 100 'and the first and second oil inlets 27 and 28 are discharged. Communication and braking are quick.

6A and 6B illustrate a cylinder body and a piston during retraction according to a second embodiment of the present invention, and FIGS. 7A and 7B illustrate a cylinder body and a piston during retreat according to a third embodiment of the present invention. 8A and 8B are views illustrating a cylinder body and a piston during retraction according to a fourth embodiment of the present invention, and FIGS. 9A and 9B illustrate a cylinder body and a piston during retraction according to a fifth embodiment of the present invention. It is a figure which shows. 6B, 7B, 8B, and 9B are diagrams corresponding to FIG. 4B.

Hereinafter, another embodiment according to the present invention will be described with reference to the above drawings, and the descriptions of the components of the first embodiment may be equally applied below unless otherwise specified.

As shown in FIGS. 6A and 6B, the diameter D1 of the inlet 211 of the one or more communication ports 210 of the plurality of communication ports 200 is larger than the diameter D2 of the other communication holes 220. It may be formed large, thereby preliminary pressure discharge may occur through the communication port 210 having a large diameter inlet 211. In this case, the preliminary pressure discharge means that a small amount of oil first flows out of the piston 230 through the communication port 210 to lower the pressure in the hydraulic chamber, and is used herein in the same sense. .

In addition, as shown in FIGS. 7A and 7B, the center 312 of the inlet 311 of the one or more communication ports 310 of the plurality of communication ports 300 is the inlet 321 of the other communication ports 320. It may be formed at the rear of the piston 330 than the center 322 of the.

8A and 8B, the inlet 411 of the one or more communication ports 410 of the plurality of communication ports 400 is the inlet 421 of the communication ports 420 whose center 412 is different from each other. At the same time as the rear of the piston 430 than the center 422 of the () may be further provided with an extension 423.

9A and 9B, the inlet 511 of the one or more communication ports 510 of the plurality of communication ports 500 may be formed in a straight shape. Of course, this is exemplary, and there is no limitation in the shape of the inlet if the rear end of the inlet is located behind the piston rather than the rear end of the other communication ports.

In addition, the present invention can be variously modified.

For example, the number of communication ports is not limited. Of course, there is no limit to the number of communication ports through which pressure is preliminarily discharged. However, the number of communication ports through which pressure is preliminarily discharged is preferably within half of the total number of communication holes.

1 is a cross-sectional view showing a conventional master cylinder.

FIG. 2A is an enlarged cross-sectional view of part A of FIG. 1.

FIG. 2B is a cross-sectional view corresponding to FIG. 2A, illustrating the advanced state of the piston. FIG.

FIG. 2C is a cross-sectional view corresponding to FIG. 2A, illustrating a retracted state of the piston. FIG.

3 is a cross-sectional view showing a master cylinder according to the first embodiment of the present invention.

4A and 4B are diagrams showing a cylinder body and a piston during retraction according to the first embodiment of the present invention.

5 is a cross-sectional view showing a master cylinder according to the first embodiment of the present invention, showing a state in which the piston is pressed.

6A and 6B are diagrams showing a cylinder body and a piston during retraction according to a second embodiment of the present invention.

7A and 7B show a cylinder body and a piston during retraction according to a third embodiment of the present invention.

8A and 8B are views showing a cylinder body and a piston during retraction according to a fourth embodiment of the present invention.

9A and 9B are views showing a cylinder body and a piston during retraction according to a fifth embodiment of the present invention.

* Description of symbols on the main parts of the drawings *

      20 Cylinder Body 21 Bore

      23 1st hydraulic chamber 24 2nd hydraulic chamber

      25 1st oil outlet 26 2nd oil outlet

      27 1st oil inlet 28 2nd oil inlet

      30 First piston 40 Second piston

      32 Support 33 Retainer

      34 end 35 stepping

      100 communication holes 110, 120 communication holes

      111 inlet 112 extension

Claims (6)

A cylinder body having an oil inlet port and a hydraulic chamber; and A piston having a plurality of communication ports for communicating the oil inlet port and the hydraulic chamber, advancing from the bore of the cylinder body and raising the pressure inside the hydraulic chamber; And a sealing member provided between the cylinder body and the piston to selectively block the flow of oil through the communication port of the piston. And when the pressure of the hydraulic chamber is released, the pressure of the hydraulic chamber is preliminarily discharged through at least one of the plurality of communication ports. The method of claim 1, At least one communication port of the plurality of communication ports communicates with the oil inlet before other communication holes. The method of claim 2, The diameter of the inlet of the at least one communication port of the plurality of communication port is a master cylinder, characterized in that formed larger than the other communication port. The method of claim 2, Inlet of at least one of the communication port of the plurality of communication port is characterized in that it has an extension extending toward the rear of the piston. The method of claim 4, wherein Master extension, characterized in that the extension is made of a slit form. The method according to claim 1, wherein The center of the inlet of the at least one communication port of the plurality of communication spheres is formed in the rear of the piston than the center of the inlet of the other communication spheres.

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