JP2011240723A - Master cylinder and brake system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a master cylinder and a brake system using the master cylinder capable of reliably detecting the deterioration in sealing property of at least one of an isolation cup seal and a separation cup seal or no-mounting of at least one of both the seals.SOLUTION: Upon detection determining operation, an SEP 7 is pressed to the rear side like an arrow mark by an air pressure, the SEP 7 is moved to the rear side and the tip of an outer lip 22c of the SEP 7 is brought into contact with the rear wall 2c of an annular groove 2b. When the sealing property is deteriorated due to foreign matter such as contamination, air flows to the tip of the outer lip 22c through the outer circumference of the outer lip 22c. Further, the air flows to the rear side through a radial groove 22e and the tip of an inner lip 22b. By detecting the air pressure of the air that flows to the rear side, the deterioration of the sealing property of the SEP 7 is detected.

Description

  The present invention relates to the technical field of a master cylinder that is used in a hydraulic system such as a brake system to generate hydraulic pressure, and in particular, between the inside and outside of a cylinder hole into which a piston is slidably fitted and inserted. TECHNICAL FIELD OF THE INVENTION Technical Field of Master Cylinder with Isolation Cup Seal for Sealing or Master Cylinder with Isolation Cup Seal and Separation Cup Seal for Partitioning Multiple Hydraulic Chambers in Cylinder Holes, and Technical Field of Brake System Using the Same It is.

Conventionally, many brake systems using a master cylinder that generates brake fluid pressure have been proposed as brake systems for vehicles such as automobiles. As a conventional master cylinder, an isolation seal (ISO) that seals a cylinder hole into which a piston is slidably fitted and inserted, and a separation cup seal that separates two hydraulic chambers (separation) A tandem master cylinder having a seal (SEP) has been proposed (see, for example, Patent Document 1).

  FIG. 5 is a longitudinal sectional view showing a master cylinder described in Patent Document 1. As shown in FIG. In the following description, the front and the rear correspond to the left and right in FIG. In that case, the front indicates the direction of operation of the piston, and the rear indicates the direction of non-operation of the piston.

  In FIG. 5, 1 is a master cylinder, 2 is a cylinder body, 2a is a cylinder hole, 3 is a primary piston, 4 is a first cup seal, 5 is a second cup seal, 6 is a secondary piston, 7 is a third cup seal, 8 is a fourth cup seal, 9 is a primary hydraulic pressure chamber, 10 is a secondary hydraulic pressure chamber, 11 is a primary return spring, 12 is a secondary return spring, 13 is a first brake fluid supply / discharge hole, and 14 is a second brake fluid supply. Exhaust hole, 15 is a first radial hole, 16 is a second radial hole, 17 is a first reservoir connection port, 18 is a second reservoir connection port, 19 is a first output port, 20 is a second output port, and 21 is a reservoir.

When the master cylinder 1 is in an inoperative state, both pistons 3 and 6 are in the retreat limit position shown in FIG. In the retreat limit position of the primary piston 3, a part of the first radial hole 15 is located behind the front end portion of the inner lip of the second cup seal 5. At this time, the primary hydraulic chamber 9 communicates with the first reservoir connection port 17 and further communicates with the interior of the reservoir 21. In addition, at the retreat limit position of the secondary piston 6, a part of the second radial hole 16 is located behind the front end portion of the inner lip of the fourth cup seal 8. At this time, the secondary hydraulic chamber 10 communicates with the second reservoir connection port 18 and further communicates with the reservoir 21. Therefore, no hydraulic pressure is generated in the primary hydraulic chamber 9 and the secondary hydraulic chamber 10.

  The booster is activated by the brake operation by depressing the brake pedal, the primary piston 3 moves forward by the output of the booster, and the first radial hole 15 moves forward from the front end of the inner lip of the second cup seal 5. To do. Further, the secondary piston 6 advances by the advance of the primary piston 3, and the second radial hole 16 moves forward from the front end portion of the inner lip of the fourth cup seal 8. When the loss stroke of the brake system disappears, hydraulic pressure is generated in the primary hydraulic chamber 9 and the secondary hydraulic chamber 10. The hydraulic pressure in the primary hydraulic chamber 9 and the secondary hydraulic chamber 10 is supplied to a brake cylinder such as a wheel cylinder (not shown) through the first output port 19 and the second output port 20, respectively. As a result, the brake cylinder generates a brake amount, and the wheel is braked.

  When the brake pedal is released, the booster is deactivated and the output of the booster disappears. Then, the secondary piston 6 is retracted by the secondary return spring 12 and the primary piston 3 is retracted by the primary return spring 11, and the master cylinder 1 is brought into the inoperative state shown in FIG. Accordingly, the hydraulic pressure in the primary hydraulic chamber 9 and the secondary hydraulic chamber 10 disappears, and the hydraulic pressure in the brake cylinder disappears, and the brake is released.

  In the master cylinder described in Patent Document 1, the first cup seal 4 constitutes ISO, and the third cup seal 7 constitutes SEP (hereinafter also referred to as ISO4 and SEP7). The same cup seal 22 shown in FIG. 6 is used for these ISO4 and SEP7. As shown in FIG. 6, the cup seal 22 is formed in an annular shape as a whole, and the radial cross section is formed in a substantially U shape or a substantially inverted U shape. That is, the cup seal 22 includes an annular base 22a extending in the radial direction, an annular inner lip 22b extending in the axial direction from the base 22a, and an annular outer lip 22c extending in the axial direction from the base 22a outside the inner lip 22b. Have In that case, in the cup seal 22 described in Patent Document 1, the axial length of the outer lip 22c is longer than the axial length of the inner lip 22b.

  In ISO4, the cup seal 22 is mounted in an annular groove formed at the inlet of the cylinder hole 2a of the cylinder body 2 so that both the inner lip 22b and the outer lip 22c extend forward. And the primary piston 3 penetrates the cup seal 22 of ISO4 so that sliding is possible. At this time, the ISO 4 prevents the brake fluid in the primary hydraulic chamber 9 from leaking outside from the cylinder hole 2a.

  In SEP7, the cup seal 22 is mounted in an annular groove formed in the cylinder hole 2a of the cylinder body 2 so that the inner lip 22b and the outer lip 22c both extend rearward. And the secondary piston 6 penetrates the cup seal 22 of SEP7 so that sliding is possible. At this time, the SEP 7 prevents the brake fluid in the primary hydraulic chamber 9 from flowing toward the second brake fluid supply / discharge hole 14. That is, SEP7 partitions the primary side and the secondary side.

  On the other hand, a master cylinder has been proposed in which a radial groove is provided in a cup seal that divides and forms a primary hydraulic chamber and a secondary hydraulic chamber (see, for example, Patent Document 2). In that case, each cup seal described in Patent Document 2 corresponds to the second cup seal 5 and the fourth cup seal 8 described in Patent Document 1, respectively.

As shown in FIG. 7, the cup seal 23 described in Patent Document 2 is formed in an annular shape as a whole, and is formed from a base 23a, an inner lip 23b, and an outer lip 23c in a substantially U-shaped cross section. In this case, the axial length of the inner lip 23b is longer than the axial length of the outer lip 23c. The base 23a has a radial groove 23d and a radial groove 23e at the tip of the inner lip 23b. These radial grooves 23d and 23e enable smooth replenishment of brake fluid. Therefore, in the master cylinder described in Patent Document 2, the fluid tightness of the primary hydraulic chamber and the secondary hydraulic chamber is ensured, and the replenishability of the brake fluid from the reservoir is improved.

By the way, if foreign matters such as contamination are present in the annular grooves in which ISO4 and SEP7 described in Patent Document 1 are respectively mounted, even if ISO4 and SEP7 are mounted in the annular grooves, the sealing performance of ISO4 and SEP7 is deteriorated. . Further, if there is a forgotten mounting of ISO4 and SEP7, the sealing is not performed by ISO4 and SEP7. Therefore, in these cases, liquid leakage occurs. Therefore, conventionally, in the assembly process of the master cylinder 1, I
By performing the inspection confirmation work of the mounting state of SO4 and SEP7, the deterioration of the sealing performance of ISO4 and SEP7 or the non-mounting of ISO4 and SEP7 is detected.

For example, as shown in FIG. 8 (a), the inspection confirmation work of the mounting state of the SEP7 is as shown in FIG. 8 (b) in a state where the primary piston 3 and the secondary piston 6 are fitted and inserted into the cylinder hole 2a. The pipe 24 is attached to the primary first output port 19 and the open end of the pipe 24 is closed with a stopper. A pressure sensor 25 is attached to the pipe 24. Further, the second output port 20 on the secondary side is closed so that the pressure in the secondary hydraulic chamber 10 can be maintained. Then, a predetermined air pressure (for example, 0.5 MP) is supplied from the second reservoir connection port 18.
a) or the like (corresponding to the pressure fluid of the present invention) is supplied into the secondary hydraulic chamber 10. When the sealing performance of the SEP 7 is deteriorated due to contamination or the SEP 7 is not attached, the air supplied into the secondary hydraulic chamber 10 passes through the SEP 7 and flows into the primary hydraulic chamber 9. The air that has flowed into the primary hydraulic chamber 9 further flows into the pipe 24 through the first output port 19. For this reason, since the pressure in the pipe 24 is increased, the increased pressure is detected by the pressure sensor 25, so that a decrease in sealing performance due to contamination or the like or the non-installation of the SEP 7 is detected.

Japanese Patent Laid-Open No. 2007-308053. JP-A-2005-273714.

  By the way, in the inspection confirmation work of the mounting state of the SEP7 as described above, the SEP7 is moved in the annular groove by the air supplied into the secondary hydraulic pressure chamber 10, and the tip of the outer lip 22c of the cup seal 22 of the SEP7 is annular. In some cases, the groove abuts against the side wall of the groove. The abutting portion is sealed by the abutting of the outer lip 22c on the side wall of the annular groove.

  However, although the sealing performance of the outer peripheral portion of the outer lip 22c is deteriorated due to contamination or the like existing in the annular groove in this manner, the air flows into the primary hydraulic pressure by the sealing of the contact portion described above. It does not flow into the chamber 9. As a result, there is a problem that even if the air pressure is not detected by the pressure sensor 25 and the inspection confirmation work is performed, the SEP 7 is passed in the normal state. This problem may also occur with ISO4.

  Further, the cup seal that partitions the hydraulic pressure chamber of the master cylinder described in Patent Document 2 is provided with radial grooves for replenishing brake fluid at the tip of the base and the inner lip, respectively. However, in the master cylinder described in Patent Document 2, no consideration is given to the problems of ISO 4 and SEP 7 described in Patent Document 1 described above.

  The present invention has been made in view of such circumstances, and an object of the present invention is to more reliably detect deterioration or non-mounting of at least one of an isolation cup seal and a separation cup seal. A master cylinder and a brake system using the master cylinder are provided.

In order to solve the above-described problems, a master cylinder according to the present invention has a cylinder body, a cylinder hole of the cylinder body, a base, an inner lip, and an outer lip, and the radial cross section is formed in a substantially U shape. In addition, an annular isolation cup seal that is provided in the opening of the cylinder hole and seals the cylinder hole to the outside, and penetrates the isolation cup seal to be fluid-tight and slidable into the cylinder hole. A master cylinder having a fitted and inserted piston and a fluid pressure chamber formed in a cylinder hole of the cylinder body, in which fluid pressure is generated when the piston is operated and the fluid pressure disappears when the piston is not operated. The isolation cup seal is disposed in an annular groove provided in the cylinder hole, During the inspection confirmation operation of the isolation cup seal according to the above, the portion of the isolation cup seal that moves and contacts the rear wall of the annular groove or the isolation cup seal moves and contacts A radial groove is provided on the rear wall of the annular groove.

  Further, in the master cylinder according to the present invention, the isolation cup seal is disposed in the annular groove, and the inner lip and the outer lip extend in the operation direction of the piston. The part of the isolation cup seal that abuts is the base, and the radial groove is provided on a rear wall of the annular groove against which the base or the base abuts.

  Further, in the master cylinder according to the present invention, the piston includes two pistons, a primary piston and a secondary piston, which are arranged in series in the cylinder, and the hydraulic chamber includes the primary piston and the secondary piston. It consists of two hydraulic chambers: a primary hydraulic chamber provided between the cylinder body and a secondary hydraulic chamber provided between the cylinder body and the secondary piston. And an annular separation cup seal that divides the primary hydraulic chamber side and the secondary hydraulic chamber side between the primary hydraulic chamber and the secondary hydraulic chamber. And the separation cup seal is disposed in a second annular groove provided in the cylinder hole. When the separation cup seal is inspected and confirmed by pressure fluid, the separation cup seal moves and a part of the separation cup seal that contacts the rear wall of the second annular groove or the separation cup seal moves and contacts. A second radial groove is provided on the rear wall of the second annular groove.

  Further, in the master cylinder according to the present invention, the separation cup seal is disposed in the second annular groove so that the inner lip and the outer lip extend in a non-operating direction of the piston. Is the tip of the outer lip, and a second radial groove is provided on the rear wall of the second annular groove with which the tip of the outer lip or the tip of the outer lip contacts. It is characterized by being.

  Further, in the master cylinder according to the present invention, when the radial groove is provided in the base of the isolation cup seal and the second radial groove is provided in the outer lip of the separation cup seal, The isolation cup seal and the separation cup seal are composed of the same cup seal in which radial grooves are provided in the base and the outer lip, respectively, or the radial groove is provided in the rear wall of the annular groove and the first When the second radial groove is provided on the rear wall of the second annular groove, the isolation cup seal and the separation cup seal are configured by the same cup seal without the radial groove. It is a feature.

  Furthermore, the brake system according to the present invention operates a brake by a brake operation member, a master cylinder that operates by operating the brake operation member to generate brake fluid pressure, and a brake force that is generated by the fluid pressure of the master cylinder. In the brake system including the brake cylinder, the master cylinder is any one of the above-described master cylinders of the present invention.

  According to the master cylinder of the present invention configured as described above, the radial groove is provided in the base of the isolation cup seal disposed in the annular groove of the cylinder hole or the annular groove of the cylinder hole. Accordingly, it is possible to more reliably and easily detect a decrease in the sealing performance or non-mounting of the isolation cup seal due to foreign matters such as contamination during the inspection confirmation work.

  In addition, a second radial groove is provided in the outer lip of the separation cup seal disposed in the second annular groove of the cylinder hole or in the second annular groove of the cylinder. Therefore, it is possible to more reliably and more easily detect the deterioration or non-mounting of the separation cup seal due to foreign matters such as contamination during the inspection confirmation work.

  Furthermore, when a radial groove is provided in the base of the isolation cup seal and a second radial groove is provided in the outer lip of the separation cup seal, the same cup in which the radial groove is provided in the base and the outer lip, respectively. Seals are used for isolation cup seals and separation cup seals. When the radial groove is provided in the annular groove and the second radial groove is provided in the second annular groove, the same cup seal in which neither the base groove nor the outer lip is provided is isolated. Used for the separation cup seal and the separation cup seal. As a result, it is possible to effectively reduce the cost by sharing the cup seal components.

  In particular, when the radial groove or the second radial groove is provided in the annular groove or the second annular groove, it is not necessary to provide the radial groove in the cup seal, and a conventionally known cup in which no radial groove is provided. A seal can be used. Therefore, the cost of the master cylinder can be reduced.

  On the other hand, according to the brake system of the present invention, the above-described master cylinder of the present invention is used. Therefore, since it is possible to reliably detect a decrease in the sealing performance of the isolation cup seal and the separation cup seal, the brake can be operated more reliably, and the reliability of the brake operation can be improved.

It is a figure showing typically a brake system using an example of an embodiment of a master cylinder concerning the present invention. The cup seal used for the isolation cup seal and separation cup seal of the master cylinder of this example is shown, (a) is a sectional view taken along line IIA-IIA in (b) and (c), and (b) is from the base side. The figure seen, (c) is the figure seen from the outer lip side. (A) thru | or (d) is a figure explaining the behavior of the separation cup seal at the time of an inspection confirmation operation | work. The other example of embodiment of the master cylinder of this invention is shown, (a) And (b) is a figure similar to FIG. 3 (a) and (d) explaining the behavior of a separation cup seal, (c) These are the figures explaining the behavior of the isolation cup seal | sticker at the time of an inspection confirmation operation | work. It is a longitudinal cross-sectional view which shows the master cylinder of patent document 1. It is sectional drawing which shows the separation cup seal of patent document 1. 10 is a cross-sectional view showing a cup seal that partitions a hydraulic chamber described in Patent Document 2. FIG. (A) is a figure which shows the state before the air in the inspection confirmation operation | work of a cup seal is supplied, (b) is a figure explaining the inspection confirmation operation | work of a separation cup seal.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a brake system using an example of an embodiment of a master cylinder according to the present invention. The same components as those of the above-described conventional example are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 1, the brake system 31 of this example includes a brake pedal 32, a booster 33 such as a negative pressure booster, a tandem master cylinder 1, a reservoir 21, and a brake cylinder 34 such as a wheel cylinder. ing. The master cylinder 1 is basically the same as the master cylinder 1 described in Patent Document 1 described above. Therefore, like the master cylinder 1 described in Patent Document 1, the booster 33 is activated by depressing the brake pedal 32, and the primary hydraulic pressure chamber 9 and the secondary hydraulic pressure of the master cylinder 1 are output by the output of the booster 33. A hydraulic pressure is generated in the chamber 10. Then, the brake cylinder 34 generates a braking force by the hydraulic pressure of the master cylinder 1 and the wheels 35 are braked.

  The master cylinder 1 of this example also has first to fourth cup seals 4, 5.7, and 8 having a substantially U-shaped radial cross section. In that case, the second and fourth cup seals 5 and 8 are cup seals that partition the primary hydraulic pressure chamber 9 and the secondary hydraulic pressure chamber 10, respectively. The first cup seal 4 is the aforementioned ISO, and the third cup seal 7 is the aforementioned SEP. In that case, also in the master cylinder 1 of this example, the same cup seal 22 shown in FIG. 2A is used for ISO 4 and SEP 7. The cup seal 22 includes an annular base 22a extending in the radial direction, an annular inner lip 22b extending in the axial direction from the base 22a, and an annular outer lip 22c extending in the axial direction from the base 22a outside the inner lip 22b. Have. In that case, in the cup seal 22 of this example, the axial length of the outer lip 22c and the axial length of the inner lip 22b are substantially the same length. However, the present invention is not limited to this, and one of the axial length of the outer lip 22c and the axial length of the inner lip 22b can be increased.

As shown in FIGS. 2A and 2B, a predetermined number of radial grooves 22d are formed at predetermined intervals in the circumferential direction on the base 22a of the cup seal 22 of this example. Also, as shown in FIGS. 2A and 2C, a predetermined number of radial grooves 22e are formed at predetermined intervals in the circumferential direction at the tip of the outer lip 22c.

  Also in the master cylinder 1 of this example, as the ISO 4, the cup seal 22 is mounted in the annular groove formed at the inlet of the cylinder hole 2a of the cylinder body 2 so that both the inner lip 22b and the outer lip 22c extend forward. Has been. And the primary piston 3 penetrates the cup seal 22 of ISO4 so that sliding is possible. At this time, the ISO 4 prevents the brake fluid in the primary hydraulic chamber 9 from leaking outside from the cylinder hole 2a.

  Further, as SEP7 of this example, the cup seal 22 is mounted in an annular groove formed in the cylinder hole 2a of the cylinder body 2 so that both the inner lip 22b and the outer lip 22c extend rearward. And the secondary piston 6 penetrates the cup seal 22 of SEP7 so that sliding is possible. At this time, the SEP 7 prevents the brake fluid in the primary hydraulic chamber 9 from flowing toward the second brake fluid supply / discharge hole 14. That is, SEP7 partitions the primary side and the secondary side.

  In the master cylinder 1 of this example configured as described above, the inspection confirmation work of the mounting state of ISO 4 and SEP 7 is performed in the same manner as described above during the assembly process of the master cylinder 1 as described above. The behavior of ISO4 and SEP7 in this inspection confirmation work will be described.

  FIGS. 3A to 3D are diagrams for explaining the behavior of the SEP 7 in the inspection confirmation work. As shown in FIG. 3A, the cup seal 22 is mounted in the annular groove 2 b of the cylinder body 2. In this state, in the same manner as described above, the pipe 24 is attached to the first output port 19 on the primary side and the open end of the pipe 24 with the primary piston 3 and the secondary piston 6 fitted and inserted into the cylinder hole 2a. Is closed with a stopper. A pressure sensor 25 is attached to the pipe 24. Further, the second output port 20 on the secondary side is closed so that the pressure in the secondary hydraulic chamber 10 can be maintained. Then, air having a predetermined air pressure is supplied from the second reservoir connection port 18 into the secondary hydraulic pressure chamber 10.

  As shown in FIG. 3B, the air pressure of the air supplied into the secondary hydraulic chamber 10 pushes the SEP 7 backward as indicated by an arrow. For this reason, SEP7 moves back and the front-end | tip of the outer lip 22c of SEP7 contact | abuts to the rear wall 2c of the annular groove 2b. That is, the outer lip 22c is a contact portion that contacts the rear wall 2c of the annular groove 2b. At this time, since the radial groove 22e is formed at the tip of the outer lip 22c, even if the tip of the outer lip 22c contacts the rear wall 2c, the outer lip 22c is not sealed. If foreign matter such as contamination is present at the bottom of the annular groove 2b, the sealing performance between the outer peripheral surface of the outer lip 22c of the cup seal 22 and the bottom of the annular groove 2b is deteriorated. Therefore, the air supplied into the secondary hydraulic chamber 10 passes between the outer peripheral surface of the outer lip 22c whose sealing performance is lowered as indicated by the arrow and the bottom of the annular groove 2b, and the tip of the outer lip 22c. It flows toward.

  Further, as shown by an arrow in FIG. 3C, air flows through the radial groove 22e toward the inner lip 22b. Further, as shown by an arrow in FIG. 3D, air deflects the outer lip 22 toward the inner lip 22b, and the outer lip 22 deflects the inner lip 22b toward the secondary piston 6. The air flows toward the primary hydraulic chamber 9 through a gap between the tip of the inner lip 22b and the rear wall 2c. Since the air that has flowed into the primary hydraulic chamber 9 flows into the pipe 24 through the first output port 19, the pressure in the pipe 24 rises. This pressure increase is detected by the pressure sensor 25. Thus, in the master cylinder assembling process, a decrease in the sealing performance of the SEP 7 due to foreign matters such as contamination is detected. Similarly, non-mounting of the SEP 7 into the annular groove 2b is also detected. In that case, the non-mounting of the SEP 7 into the annular groove 2b can be detected separately from the decrease in the sealing performance of the SEP 7 because the pressure increase in the pipe 24 is quick and large.

  On the other hand, ISO4 is basically the same as in SEP7. However, in ISO4, the extending direction of inner lip 22b and outer lip 22c is opposite to that in SEP7. Comes into contact with the rear wall 2c of the annular groove 2b. In this case, the radial groove 22d of the base 22a does not seal between the rear surface of the base 22a and the rear wall 2c. In the case of ISO 4, air is supplied from the first reservoir connection port 17 to the primary hydraulic pressure chamber 9 during the inspection confirmation work. If foreign matter such as contamination is present in the annular groove in which the ISO 4 is disposed, the sealing performance between the outer peripheral surface of the outer lip 22c of the ISO 4 and the bottom of the annular groove is deteriorated. Therefore, the air supplied to the primary hydraulic pressure chamber 9 passes from the opening end of the cylinder hole 2a to the outside through the radial groove 22d between the outer peripheral surface of the outer lip 22c and the bottom of the annular groove whose sealing performance is lowered. leak. By detecting the air that has flowed out, a decrease in the sealing performance of ISO 4 is detected. The non-installation of ISO 4 is detected in the same manner.

According to the cup seal 22 and the master cylinder 1 of this example, the radial groove 22d is provided in the base 22a of the cup seal 22 of ISO4. Accordingly, it is possible to more reliably and more easily detect a decrease in the sealing performance or non-mounting of ISO 4 due to foreign matters such as contamination. Further, the radial groove 22 is formed in the outer lip 22c of the cup seal 22 of the SEP7.
e. Accordingly, it is possible to more reliably and more easily detect the deterioration or non-mounting of the SEP 7 due to contaminants such as contamination.

Moreover, since the same cup seal 22 can be used for ISO4 and SEP7, it is possible to effectively reduce the cost by sharing parts.
Other configurations and other operational effects of the master cylinder 1 of this example are the same as those of the master cylinder described in Patent Document 1 described above. In that case, the master cylinder described in Patent Document 1 has a flow control valve, but is not necessary in the master cylinder 1 of this example.

  On the other hand, according to the brake system 31 of this example, the master cylinder 1 of this example is used. Therefore, since it is possible to reliably detect a decrease in the sealing performance of ISO4 and SEOP7, the brake can be operated more reliably and the reliability of the brake operation can be improved.

  Note that the SEP 7 is moved backward by supplying air to the secondary hydraulic chamber 10 at the time of the inspection confirmation work, the tip of the inner lip 22b comes into contact with the rear wall 2c, and between the inner lip 22b and the rear wall 2c. In the case where a seal is generated, a radial groove similar to the radial groove 22e can also be provided at the tip of the inner lip 22b.

  FIG. 4 shows another example of the embodiment of the master cylinder of the present invention, and (a) and (b) are diagrams similar to FIGS. 3 (a) and 3 (d) for explaining the behavior of the separation cup seal, (C) is a figure explaining the behavior of the isolation cup seal at the time of the inspection confirmation work.

In the above-described example, the radial seals 22d and 22e are provided in the cup seal 22 of the master cylinder 1, but as shown in FIGS. 4A to 4C, the cup seal 22 constituting the SEP7 and ISO4 of this example. Then, the radial grooves 22d and 22e are not provided. In the master cylinder 1 of this example, a predetermined number of radial grooves 2d are provided at a predetermined interval in the circumferential direction on the rear wall 2c of the annular groove 2b. Even when the tip of the outer lip 22c or the rear end of the base 22a comes into contact with the rear wall 2c when the air pressure of the air acts on the cup seal 22 in the inspection confirmation work, the cup seal 22 moves rearward. Air flows through the radial groove 2d. Then, by detecting the air pressure of the pipe 24 with the pressure sensor 25 or detecting the outflow of air, the sealing performance of the cup seal 22 disposed in the annular groove 2b is lowered or the cup seal 22 is not attached. Detection and confirmation can be surely and more easily performed.

In this example, ISO 4 and SEP 7 do not need to be provided with a radial groove, and a conventionally known cup seal without a radial groove can be used. Therefore, the cost of the master cylinder 1 can be reduced.
Other configurations and other functions and effects of the master cylinder 1 in this example are the same as those in the above example.

In addition, this invention is not limited to each above-mentioned example, A various design change is possible. For example, in the above example, a tandem master cylinder is used, but the present invention can also be applied to a single master cylinder. In this case, since SEP7 is not provided, the radial groove may be provided only in the radial groove 22d provided in the base 22a of ISO4 or in the annular groove in which ISO4 is provided. In the above-described examples, the same cup seal is used for ISO4 and SEP7, but different cup seals can be used for ISO4 and SEP7. In such a case, the ISO 4 is provided with the radial groove 22d only in the base 22a, and the SEP 7 is provided with the radial groove 22e only in the outer lip 22c. 22b can also be provided with radial grooves). In short, various design changes are possible within the scope of the technical matters described in the claims.

  The master cylinder and the brake system according to the present invention are each a master cylinder or an isolation cup seal having an isolation cup seal that seals between the inside and the outside of a cylinder hole into which a piston is slidably fitted and inserted. The present invention can be suitably used for a master cylinder and a brake system having a separation cup seal that partitions a plurality of hydraulic chambers in a cylinder hole.

DESCRIPTION OF SYMBOLS 1 ... Master cylinder, 2 ... Cylinder body, 2a ... Cylinder hole, 2b ... Annular groove, 2c ... Rear wall, 2d ... Radial direction groove, 3 ... Primary piston, 4 ... 1st cup seal, 5 ... 2nd cup seal, 6 ... secondary piston, 7 ... third cup seal, 8 ... fourth cup seal, 9 ... primary hydraulic chamber, 10 ... secondary hydraulic chamber, 17 ... first reservoir connection port, 18 ... second reservoir connection port, 19 ... 1st output port, 20 ... 2nd output port, 21 ... Reservoir, 22 ... Cup seal, 22a ... Base, 22b ... Inner lip, 22c ... Outer lip, 22d, 22
e ... radial groove, 24 ... piping, 25 ... pressure sensor, 31 ... brake system, 32 ... brake pedal, 33 ... booster, 34 ... brake cylinder

Claims (6)

A cylinder body,
The cylinder hole of this cylinder body,
An annular isolation cup seal that is formed in a substantially U shape in cross section in the radial direction by the base, the inner lip, and the outer lip and is provided in the opening of the cylinder hole to seal the cylinder hole to the outside;
A piston that is inserted through the isolation cup seal in a liquid-tight and slidable manner in the cylinder hole;
In a master cylinder formed in a cylinder hole of the cylinder body and having a hydraulic chamber in which hydraulic pressure is generated when the piston is operated and the hydraulic pressure disappears when the piston is not operated,
The isolation cup seal is disposed in an annular groove provided in the cylinder hole;
During the inspection / confirmation work of the isolation cup seal with the pressure fluid, the isolation cup seal moves or the part of the isolation cup seal that abuts the rear wall of the annular groove or the isolation cup seal moves. A master cylinder, wherein a radial groove is provided on the rear wall of the annular groove in contact therewith. The isolation cup seal is disposed in the annular groove so that the inner lip and the outer lip extend in the operating direction of the piston,
The part of the isolation cup seal that contacts the rear wall of the annular groove is the base, and the radial groove is provided on the base or the rear wall of the annular groove that the base contacts. The master cylinder according to claim 1, wherein: The piston is composed of two pistons, a primary piston and a secondary piston arranged in series in the cylinder,
The fluid pressure chamber has two fluid pressure chambers: a primary fluid pressure chamber provided between the primary piston and the secondary piston, and a secondary fluid pressure chamber provided between the cylinder body and the secondary piston. Consists of
The base, the inner lip, and the outer lip have a substantially U-shaped radial cross section, and the primary hydraulic chamber side and the secondary hydraulic chamber are between the primary hydraulic chamber and the secondary hydraulic chamber. An annular separation cup seal that separates the sides,
The separation cup seal is disposed in a second annular groove provided in the cylinder hole;
When the separation cup seal is inspected and confirmed by pressure fluid, the separation cup seal moves and a part of the separation cup seal that contacts the rear wall of the second annular groove or the separation cup seal moves and contacts. The master cylinder according to claim 1 or 2, wherein a second radial groove is provided in a rear wall of the second annular groove. The separation cup seal is disposed in the second annular groove such that the inner lip and the outer lip extend in a non-operation direction of the piston;
The portion of the separation cup seal is a tip portion of the outer lip, and a second radial groove is formed on a rear wall of the second annular groove with which the tip portion of the outer lip or the tip portion of the outer lip contacts. The master cylinder according to claim 3, wherein the master cylinder is provided. When the radial groove is provided in the base of the isolation cup seal and the second radial groove is provided in the outer lip of the separation cup seal, the isolation cup seal and the separation cup seal are The base and the outer lip are each configured by the same cup seal provided with radial grooves, or the radial groove is provided on the rear wall of the annular groove and the second annular groove is provided with the first groove on the rear wall. 5. When two radial grooves are provided, the isolation cup seal and the separation cup seal are made of the same cup seal without a radial groove. Master cylinder. In a brake system comprising: a brake operation member; a master cylinder that operates by operating the brake operation member to generate a brake fluid pressure; and a brake cylinder that operates a brake by a brake force generated by the fluid pressure of the master cylinder.
The brake system according to claim 1, wherein the master cylinder is the master cylinder according to any one of claims 1 to 5.

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