JP2000309262A - Master cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly respond to the fluctuation of hydraulic pressure caused when a traction control system and vehicle stability control system are released by reducing the amount of operating fluid flowing to a reservoir at the start of a master cylinder operation and. SOLUTION: This master cylinder is provided with a throttle valve mechanism 43 which consists of a throttle function 46b which throttles flow of operating fluid from pressure generating chambers 29, 30 to a reservoir 19 during the forward stroke of pistons 27, 28 of a master cylinder 20; a valve function which opens a valve and permits flow of operating fluid from the reservoir 19 to the pressure generating chambers 29, 30 during the backward stroke of pistons 27, 28; and a relief valve function which permits flow of a large amount of operating fluid from the pressure generating chambers 29, 30 to the reservoir 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master cylinder, and more particularly to a master cylinder for a vehicle provided with a device (such as a traction control device or a vehicle stability control device) for performing brake control by pressurizing hydraulic fluid in a wheel cylinder by pumping up. The present invention relates to a master cylinder that is suitable for a vehicle that returns hydraulic fluid from a wheel cylinder to a reservoir via a hydraulic fluid passage of the master cylinder when brake control is released, and that reduces a piston invalid stroke of the master cylinder during normal operation.

[0002]

2. Description of the Related Art FIG. 20 is a sectional view showing an example of a conventional master cylinder, which is disclosed in Japanese Patent Application Laid-Open No. Hei 10-53120. The master cylinder 1 has a piston 3 slidably fitted in a cylinder hole 2 a formed in a cylinder body 2, and has a pressure generating chamber 4 defined by the piston 3 and a supply passage 5. The piston 3 has
A valve mechanism 6 and a floating throttle valve mechanism 7 are mounted on the extension of the axis. In response to the piston 3 being retracted to the return position by the return spring 8 installed in the pressure generating chamber 4, the valve mechanism 6 moves the flange 10 integral with the rod 9 away from the annular member 11 and the axial hole 12. And the flange 10 contacts the annular member 11 to close the axial hole 12 in response to the piston 3 moving forward from the return position.

The floating throttle valve mechanism 7 has a throttle hole 13a.
When the hydraulic fluid flows from the pressure generating chamber 4 through the axial hole 12 to the reservoir (not shown), the throttle action position exerts a throttle effect on the flow of the hydraulic fluid. When the floating member 13 is moved, and there is a flow of the hydraulic fluid from the reservoir to the pressure generating chamber 4 through the axial hole 12, the floating member 13 is moved to a non-throttling operation position where the throttle effect is not exerted on the flow of the hydraulic fluid. The floating member 13
To move.

Then, the piston 3 is actuated from the state where the valve mechanism 6 is open, moves forward in the left direction in the figure to close the valve mechanism 6, and the communication between the pressure generating chamber 4 and the supply passage 5 is cut off. It is. After that, the piston 3 further moves to the left,
Pressure is generated in the pressure generating chamber 4, and the working fluid is discharged from the output port 14. During the period from when the piston 3 starts to advance to when the valve mechanism 6 closes, the hydraulic fluid in the pressure generating chamber 4 escapes to the supply passage 5 through the floating throttle valve mechanism 7 and the valve mechanism 6 due to the advance of the piston 3. Due to the flow of the hydraulic fluid at that time, the floating member 13 of the floating throttle valve mechanism 6 is connected to the communication hole 1 of the case 15.
5a is closed. As a result, the hydraulic fluid in the pressure generation chamber 4 escapes to the supply passage 5 through the throttle hole 13a of the floating member 13, and the amount of the hydraulic fluid that escapes from the pressure generation chamber 4 to the supply passage 5 is reduced. Is reduced as compared with the case where the flow of the hydraulic fluid that escapes from the supply passage 5 to the supply passage 5 is not restricted.

[0005]

However, at the start of operation (when the piston advances), the master cylinder used in a vehicle equipped with a traction control device and a vehicle stability control device escapes from the pressure generating chamber 4 to the reservoir. When a throttle valve mechanism (for example, an orifice) for reducing the amount of hydraulic fluid is provided, when the traction control device or the vehicle stability control device is released, a wheel cylinder is connected to the master cylinder via a replenishing fluid passage. When the hydraulic fluid is returned to the reservoir, a throttle valve mechanism is interposed on the path, so that the return of the hydraulic fluid to the reservoir is delayed,
There has been a problem that a delay in hydraulic pressure drop of the pressure generating chamber 4 occurs.

In the case where the throttle valve mechanism is provided at a connection portion between the master cylinder and the reservoir, when the liquid is returned from the pressure generating chamber to the reservoir, a connection portion between the reservoir and the master cylinder is provided. As a result, a high pressure is generated, and a force acts in a direction in which the reservoir tank comes out, so that there is a problem that the cost is increased due to an increase in the strength of the tank holding structure. For this reason, the throttle valve mechanism has a structure that can quickly respond to an increase or decrease (ie, a pressure change) in the hydraulic fluid flow rate of the hydraulic pressure return when the traction control device or the vehicle stability control device is released. Was long awaited.

[0007] The present invention has been made in view of such a point,
The object is to solve the above problems, a vehicle provided with a traction control device and a vehicle stability control device,
Simple and non-large valve structure that can reduce the amount of hydraulic fluid that escapes to the reservoir at the start of operation of the master cylinder and can quickly respond to hydraulic pressure fluctuations when the traction control device or the vehicle stability control device is released And a master cylinder for reducing the invalid stroke of the piston.

[0008]

According to a first aspect of the present invention, a piston is slidably disposed in a cylinder hole formed in a cylinder body, and a pressure is generated by the piston and the cylinder body. A chamber for partitioning the pressure generation chamber and the reservoir, and a liquid passage for replenishing the pressure generation chamber with the hydraulic fluid, and an output port for the hydraulic fluid pressurized in the pressure generation chamber when the piston is operated. In the master cylinder that discharges to

A restricting function for restricting a flow of hydraulic fluid from the pressure generating chamber to the reservoir when the piston is operated;
At the time of return of the piston, a valve function that opens the valve to allow the flow of the hydraulic fluid from the reservoir to the pressure generating chamber, and a relief valve function that allows the flow of the hydraulic fluid from the pressure generating chamber to the reservoir. Is disposed in the liquid passage.

The throttle valve mechanism has a valve seat provided at a distal end of a connection portion of the reservoir with the cylinder body, a valve seat surface seated on the valve seat, a throttle hole, and a plurality of throttle holes substantially at the center. And a floating valve body made of an elastic material having a slit formed therein.

Alternatively, the throttle mechanism is formed at a distal end of a connecting portion between the thin plate-like or thin film-like valve seat made of an elastic material and the cylinder body of the reservoir, and the valve seat is provided on the pressure generating chamber side. And a rib that abuts from
A locking portion for locking the valve seat, and in a normal state where the valve seat is not deformed, a throttle is provided between the outer peripheral edge of the valve seat and the inner peripheral surface of the connection portion tip of the reservoir. Slits are formed.

[0012] Alternatively, the throttle mechanism may include two large-diameter and small-diameter thin plate-shaped or thin film-shaped valve seats made of an elastic material, and the large-diameter valve seat interposed between the small-diameter valve seats. A rib formed at the distal end of a connection portion of the reservoir with the cylinder body for contacting from the pressure generating chamber side, and a locking portion for locking the two valve seats at a substantially central portion. In the portion of the large-diameter valve seat surface, which overlaps with the small-diameter valve seal,
While forming a through-hole, in a normal state where the large-diameter valve seat is not deformed, a slit for diaphragm is formed between the outer peripheral edge of the large-diameter valve seat and the inner peripheral surface of the connection portion tip of the reservoir. Is formed.

Alternatively, the throttle mechanism may include a floating valve body made of an elastic material having a throttle hole formed therein and a valve seat for abutting the floating valve body floating in the valve axis direction, and a through-hole may be formed at the tip of the valve seat. The floating valve element moves toward the reservoir on the inner peripheral surface of the valve chamber, which has a groove, and is connected to the distal end of the reservoir with the cylinder body, and is a passage between the connection part and the cylinder body. And a seal surface formed to be inclined with respect to the valve shaft so that the valve is closed when the valve moves to the cylinder body side.

Since the present invention is constructed as described above, when the operation of the piston of the master cylinder is started, when there is a flow of the hydraulic fluid from the pressure generating chamber to the reservoir, the hydraulic fluid flows only through the throttle mechanism. Acting like flowing,
Reduce the amount of hydraulic fluid that escapes to the reservoir. Conversely, when the piston returns (when a negative pressure is generated in the pressure generation chamber), including when the traction control device (or the vehicle stability control device) of the vehicle is operated, the flow of the hydraulic fluid from the reservoir to the pressure chamber is reduced. In some cases, the check valve mechanism is opened by the flow of the hydraulic fluid, and the hydraulic fluid acts to flow mainly through the check valve mechanism.

When the traction control device (or the vehicle stability control device) is released, if a large amount of high-pressure hydraulic fluid flows from the pressure generating chamber to the reservoir,
The relief valve mechanism is opened by the large flow of the hydraulic fluid, and the hydraulic fluid acts so as to flow through the relief valve mechanism, thereby quickly responding to fluctuations in the hydraulic pressure of the master cylinder. At the same time, the mechanism can reduce the piston invalid stroke of the master cylinder.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 5 show a first embodiment of a master cylinder according to the present invention. FIG. 1 is a longitudinal sectional view of the master cylinder, and FIG. 2 is a throttle valve provided at a connection portion between a cylinder body and a reservoir. FIG. 3 is a bottom view showing the floating valve element of the throttle valve mechanism of FIG. 2, FIG. 4 is a cross-sectional view of the throttle valve mechanism in an open state, and FIG. It is sectional drawing of the valve-open state by a hydraulic fluid. The throttle valve mechanism shown in the present embodiment can be applied to both a center valve type master cylinder and a plunger type master cylinder.

In FIG. 1, the cylinder body 21 of the master cylinder 20 comprises a cylinder body 22 and a cap 23 attached thereto.
2 has two connection receiving portions 41 and 42 with the reservoir 19, and a slanted liquid passage 23 a is provided on the peripheral wall of the cap 23. A piston guide 24 is fitted in the cylinder body 22, and a sleeve 26 is fitted in the cap 23.

In the master cylinder 20, a primary piston 27 is slidably fitted to a flanged sleeve 26, and a secondary piston 28 is slidably fitted to the piston guide 24 and the sleeve 26.
A primary pressure chamber 29 and a secondary pressure chamber 30 are defined by 7 and 28.

The primary piston 27 and the secondary piston 28 have a bottomed cylindrical shape, and small holes 27a and 28a are formed in their peripheral walls. The pistons 27 and 28 are connected to a return spring 31 and an end wall 2 of the cylinder body 22 disposed therebetween.
2a and the return spring 32 disposed between
It is urged in the backward movement direction (the rightward non-operation position direction in the figure).

The primary pressure chamber 29 has a small hole 27a provided in the primary piston 27, a liquid passage 23a provided in the cap 23, and a liquid passage 2 in the cylinder body 22.
Via 2b, it can communicate with one connection receiving part 41. The secondary pressure chamber 30 can communicate with the other connection receiving portion 42 via a small hole 28a provided in the secondary piston 28, a liquid passage 24a opened in the piston guide 24, and a liquid passage 22c of the cylinder body 22. . The pressure chambers 29 and 30 can communicate with front and rear wheel cylinders (not shown) through output ports 33 and 34 formed in the cylinder body 22.

The connection portions 19a and 19b of the reservoir 19 are fitted to the two connection receiving portions 41 and 42 via seal members 40, respectively. Chambers 29 and 30 and the reservoir 1
The floating throttle valve mechanisms 43, 43, which are a kind of throttle valve mechanism, are respectively disposed in the respective liquid passages communicating with the liquid passages 9 and 9.

As shown in FIGS. 2 and 4, floating throttle valve mechanisms 43 provided in the liquid passages of the connecting portions 19a and 19b are connected to the connecting portion 1 of the reservoir 19, respectively.
A valve seat 44 formed at the distal end of each of 9a and 19b, and a valve chamber 45 defined by connecting portions 19a and 19b in each of the connection receiving portions 41 and 42, and a floating valve body is provided in the valve chamber 45. 4
6 are accommodated.

The floating valve body 46 is made of an elastic material having a valve seat surface seated on the valve seat 44, for example, a synthetic resin material.
As shown in FIG. 3, a throttle hole 46b is opened at the center, and a plurality of
For example, a disc-shaped valve body 46a in which two slits 46c having a cross shape are formed, and a disc-shaped valve body 46a
And four ribs 46d formed downward at equal angular intervals along the outer periphery of the liquid crystal panel. Notched liquid passages (replenishment liquid passages) 46e, 46e are formed between the adjacent ribs 46d, 46d. I have. The notched liquid passages 46e, 46e
Instead of e, a plurality of grooves may be provided on the cylinder body 21 side.

Normally, the floating throttle valve mechanism 43 is provided in a liquid passage in each of the connection receiving portions 41 and 42 of the cylinder body 21 of the master cylinder 20 to which the connection portions 19a and 19b of the reservoir 19 are fitted. Although each is arranged,
The present invention is not limited to this as long as it is on the working fluid replenishment passage from the pressure generating chambers 29, 30 to the reservoir 19.

When the operation of the master cylinder 20 is started, as shown in FIG.
When there is a flow of the hydraulic fluid from 9, 30 to the reservoir 19, the floating throttle valve mechanism 43 floats the floating valve body 46 by the flow of the hydraulic fluid, abuts the valve seat 44, and is in a closed state. The working fluid acts to flow upward only through the throttle hole 46b. Therefore, at the start of operation, the pressure chamber 29,
The amount of hydraulic fluid that escapes from 30 to the reservoir 19 can be reduced.

Conversely, as shown in FIG. 4, when there is a flow of the hydraulic fluid from the upper side to the lower side, that is, from the reservoir 19 to the pressure chambers 29 and 30, the floating valve body is formed by the flow of the hydraulic fluid and its own weight. 46 descends and separates from the valve seat 44 to open the valve, and the hydraulic fluid in the reservoir 19 is flushed with the valve seat 44 and the floating valve body 4.
6, it acts so as to flow to the lower pressure chambers 29, 30 through the liquid passage 46e on the outer periphery of the floating valve body 46. Therefore, when the master cylinder 20 returns, the reservoir 1
9 is a pressure chamber 29, 3 without resistance (less resistance).
Can be refilled to zero.

Also, when the traction control device or the vehicle stability control device shown in FIG. 5 is released, the operation is returned from the lower side to the upper side, that is, from the pressure chambers 29 and 30 of the master cylinder 20 to the reservoir 19. When the amount of the fluid is large, the floating throttle valve mechanism 43 is closed as described above due to the large flow of the hydraulic fluid, but the pressing force of the flow of the hydraulic fluid causes the slit 46 of the floating valve body 46 to be closed.
c is elastically deformed so as to be pushed to the reservoir 19 side, and acts to flow upward while expanding the passage. Therefore, the hydraulic fluid is returned to the reservoir 19 without resistance (low resistance). The floating valve body 46 may be configured to apply a small upward biasing force by a compression spring.

The operation of the master cylinder 20 in the first embodiment will be described focusing on the primary side, and the description of the secondary side performing the same operation will be omitted. In the non-operating state shown in FIG. 1, the piston 27 is located at the right end by the urging force of the spring 31, and the floating throttle valve mechanism 43 is in an open state. In this state, when the piston 27 operates and moves forward, the pressure in the pressure chamber 29 increases, and the hydraulic fluid is sent out from the output port 33. In the above operation, during the period from the opening to the closing of the small hole 27a of the piston 27, the pressure chamber 2
9 flows into the valve chamber 45 of the floating throttle valve mechanism 43.
Due to the flow of the hydraulic fluid at this time, the floating valve body 46 of the floating throttle valve mechanism 43 floats and comes into contact with the valve seat 44. By this abutment, the hydraulic fluid in the pressure chamber 29 is returned to the reservoir 19 only through the throttle hole 46b, but the amount of the hydraulic fluid returned is very small.

When the operation of the piston 27 is released,
The piston 27 is retracted by the urging force of the spring 31, and the pressure in the pressure chamber 29 decreases to a negative pressure.
The small hole 27a is opened, and the pressure chamber 29 is connected to the reservoir 19.
Communicate with At this time, the floating valve element 46 of the floating throttle valve mechanism 43 separates from the valve seat 44, and the pressure chamber 29
The working fluid flows with only a small resistance and is replenished.

Next, when the traction control device and the vehicle stability control device mounted on the vehicle are released, the hydraulic fluid is rapidly returned to the pressure chamber 29, and when the brake pedal is depressed, The piston 27 retreats, the small hole 27a opens, and the pressure chamber 29 communicates with the reservoir 19. At this time, there is a large flow of the hydraulic fluid from the pressure chamber 29 to the reservoir 19, and due to the flow,
As described above, the floating throttle valve mechanism 43 is in a closed state. However, the pressing force of the flow of the hydraulic fluid pushes and widens the slit 46c of the floating valve body 46, so that a large amount of the hydraulic fluid flows to the reservoir 19 immediately. Will be returned.

According to the master cylinder 20 of the first embodiment of the present invention, the vehicle is provided with a traction control device and a vehicle stability control device, and is a simple and small floating throttle valve mechanism. 43, the function of reducing the amount of hydraulic fluid escaping to the reservoir 19 at the start of the operation of the master cylinder 20 and quickly responding to the fluid pressure fluctuation when the traction control device or the vehicle stability control device is released. Can be done. At the same time, the invalid stroke of the piston of the master cylinder 20 can be reduced.

FIGS. 6 to 9 show a second embodiment of the master cylinder according to the present invention. In place of the floating throttle valve mechanism 43 as the throttle valve mechanism shown in the first embodiment, a throttle with a valve seat is used. FIG. 6 is an enlarged sectional view of the throttle valve mechanism with a valve seat of the master cylinder in a closed state, FIG. 7 is a bottom view of the throttle valve mechanism of FIG. 6, and FIG. 6 is a cross-sectional view of the throttle valve mechanism of FIG. 6 in an open state, and FIG. 9 is a cross-sectional view of the throttle valve mechanism of FIG. The throttle valve mechanism shown in the present embodiment can be applied to both a center valve type master cylinder and a plunger type master cylinder.

This throttle valve mechanism 53 with a valve seat is
As shown in FIGS. 6 and 7, connection portions 19 a and 19 b between a thin plate or a thin film valve seat 56 made of an elastic material that can be elastically deformed, for example, a synthetic resin material, and the cylinder body 21 of the reservoir 19. A rib 55 formed at the tip of the valve seat 56 and forming a valve seat 54 with which the valve seat 56 comes into contact with the pressure generating chambers 29 and 30;
And a locking portion 57 for locking the center portion of the rib 6 to the center portion 55a of the rib 55. In a normal state where the valve seat 56 is not deformed, a throttle slit 58 is formed between the outer peripheral edge of the valve seat 56 and the inner peripheral surface at the tip of the connection portion 19a, 19b of the reservoir 19. I have.

Normally, the throttle valve mechanism 5 with the valve seat is provided.
3 is a cylinder body 21 of the master cylinder 20 to which the connecting portions 19a and 19b of the reservoir 19 are fitted.
Are provided in the liquid passages in the respective connection receiving portions 41, 42, but are not limited as long as they are on the hydraulic fluid replenishment passage from the pressure generating chambers 29, 30 to the reservoir 19.

When the operation of the master cylinder 20 is started, the pressure chambers 29 and 30 are moved upward from the lower side in FIG.
When there is a flow of hydraulic fluid from the reservoir to the reservoir 19, the flow causes the valve seat 56 to abut against the valve seat 54, and the hydraulic fluid from the pressure chambers 29 and 30 flows from the outer peripheral edge of the valve seat 56 to the reservoir 19. It flows into the reservoir 19 only through the diaphragm slit 58 formed between the inner peripheral surface at the tip of each of the connecting portions 19a and 19b. Therefore, at the start of operation, the amount of the hydraulic fluid that escapes from the pressure chambers 29 and 30 to the reservoir 19 can be reduced.

Conversely, as shown in FIG. 8, when there is a flow of hydraulic fluid from the upper side to the lower side, that is, from the reservoir 19 to the pressure chambers 29 and 30, the valve seat 56 is moved by the flow and its own weight. The hydraulic fluid from the reservoir 19 is separated from the seat 54 and elastically deforms toward the pressure chambers 29 and 30 outside the valve seat 56. The hydraulic fluid from the reservoir 19 passes through an enlarged passage between the valve seat 54 and the valve seat 56 and passes through the pressure chamber. It flows to 29 and 30. Therefore, when the master cylinder 20 returns, the hydraulic fluid in the reservoir 19 is displaced by the pressure chamber 29 without resistance (less resistance).
30 can be replenished.

Also, when the traction control device or the vehicle stability control device shown in FIG. 9 is released, the operation is returned from the lower side to the upper side, that is, from the pressure chambers 29 and 30 of the master cylinder 20 to the reservoir 19. When the amount of the liquid is large, the valve seat 56 is elastically deformed toward the reservoir 19, and the passage is expanded. Therefore, the hydraulic fluid is returned to the reservoir 19 without resistance (low resistance).

FIGS. 10 to 14 show a third embodiment of the master cylinder according to the present invention. In place of the floating throttle valve mechanism 43 as the throttle valve mechanism shown in the first embodiment, FIG.
FIG. 10 is an embodiment in which a throttle valve mechanism with a double valve seat is used. FIG. 10 is an enlarged sectional view of the throttle valve mechanism with a double valve seat of the master cylinder in a closed state, and FIG. 11 is a throttle valve of FIG. FIG. 12 is an enlarged sectional view of a portion A in FIG. 10, FIG. 13 is a sectional view of the throttle valve mechanism in an open state of FIG. 10, and FIG. 14 is an operation of the throttle valve mechanism in FIG. It is sectional drawing of the valve-open state by a liquid. The throttle valve mechanism with a double valve seat shown in the present embodiment can be applied to both a center valve type master cylinder and a plunger type master cylinder.

This throttle valve mechanism 73 with a double valve seat 73
As shown in FIGS. 10 to 12, a large-diameter valve seat 76, a small-diameter valve seat 77, a thin plate or a thin film made of an elastic material which can be elastically deformed, for example, a synthetic resin material, and the reservoir 19 Said cylinder body 2
1 are formed at the tips of the connecting portions 19a and 19b,
While overlapping the small diameter valve seats 76 and 77 at the center,
A rib 75 having a valve seat 74 with which the large-diameter valve seat 76 abuts from the pressure generating chambers 29, 30 side with the small-diameter valve seat 77 interposed therebetween; And a locking portion 78 for locking the central portion of the rib 75 at the central portion 75a of the rib 75.

Then, the large-diameter valve seat 76
A plurality of through holes 76a as relief ports are formed in a portion overlapping with the small-diameter valve seal 77, and in a normal state where the large-diameter valve seat 76 is not deformed, the outer peripheral edge of the large-diameter valve seat 76 and Reservoir 1
An aperture slit 79 is formed between the connection portion 19a and the inner peripheral surface of the distal end of the connection portion 19b.

Normally, the throttle valve mechanism 73 with a double valve seat is provided in the connection receiving portions 41 and 42 of the cylinder body 21 of the master cylinder 20 to which the connecting portions 19a and 19b of the reservoir 19 are fitted. Although they are respectively disposed in the liquid passages, the present invention is not limited to this as long as they are on the hydraulic fluid replenishment passage from the pressure generating chambers 29 and 30 to the reservoir 19.

When the operation of the master cylinder 20 is started, as shown in FIG.
When there is a flow of hydraulic fluid from zero to the reservoir 19, the flow causes the large-diameter valve seat 76 to abut against the valve seat 74, and the hydraulic fluid from the pressure chambers 29 and 30 causes the outer peripheral edge of the large-diameter valve seat 76 to flow. And the connecting portion 19a, 1 of the reservoir 19
The fluid flows into the reservoir 19 only through the throttle slit 79 formed between the tip 9b and the inner peripheral surface of the tip 9b (at this time, the through hole 76a as a relief port is closed). Therefore, at the start of operation, the amount of the hydraulic fluid that escapes from the pressure chambers 29 and 30 to the reservoir 19 can be reduced.

Conversely, as shown in FIG.
That is, when there is a flow of the hydraulic fluid from the reservoir 19 to the pressure chambers 29 and 30, the flow causes the large-diameter valve seat 76 to separate from the valve seat 74 and elastically deform to the pressure chambers 29 and 30 side. Outside the seat 76, the hydraulic fluid from the reservoir 19 is flushed with the valve seat 74 and the large diameter valve seat 76.
Flows into the pressure chambers 29 and 30 through the enlarged passage. Therefore, when the master cylinder 20 returns, the hydraulic fluid in the reservoir 19 can be replenished to the pressure chambers 29 and 30 without resistance (less resistance).

As in the case of releasing the traction control device and the vehicle stability control device shown in FIG.
When the amount of hydraulic fluid returned from the lower side to the upper side, that is, from the pressure chambers 29 and 30 of the master cylinder 20 to the reservoir 19 is large, the small-diameter valve seat 77 is elastically deformed toward the reservoir 19 and the large-diameter valve seat A through hole 76a as a relief port formed in 76 opens. As a result, the passage is enlarged. Therefore, the hydraulic fluid is returned to the reservoir 19 without resistance (low resistance).

FIGS. 15 to 19 show a fourth embodiment of the master cylinder of the present invention. FIG. 15 is a longitudinal sectional view of the master cylinder and the reservoir, and FIG. FIG. 17 is an enlarged sectional view of the valve,
15 is an enlarged sectional view of a throttle valve mechanism provided at a connection portion between the cylinder body and the reservoir in a closed state, FIG. 18 is a sectional view of the throttle valve mechanism in an open state of FIG. 15, and FIG.
It is sectional drawing of the valve-opening state by the hydraulic fluid of the throttle valve mechanism of No. 5. The throttle valve mechanism shown in the present embodiment can be applied to both a center valve type master cylinder and a plunger type master cylinder.

15 to 17, the master cylinder 100 has a slidable primary piston 104 and a secondary piston 105 inserted into a cylinder hole 103 formed in a cylinder body 102 of a cylinder body 101. A primary pressure chamber 106 is defined between 104 and the secondary piston 105, and a secondary pressure chamber 107 is defined on the outer end side of the secondary piston 105.

The master cylinder 100 is seated when the piston 104 operates, restricts the flow of the hydraulic fluid from the pressure chamber 106 to the reservoir 119, and has a floating valve body 146 that opens when the piston 104 is not operating. The throttle valve mechanisms 143, 143 are disposed in the replenisher passages 108, 109. Each of the floating throttle valve mechanisms 143 and 143 has a floating valve body 146 made of an elastic material having a throttle hole 146b (see FIG. 17) at its center, for example, a synthetic rubber material.
And a valve seat 144 with which the floating valve body 146 comes in contact with or separates from the cylinder body 1 of the reservoir 119.
01 are formed at the ends of the connecting portions 119a and 119b.

The cylinder body 101 includes the cylinder body 1
02, two cylindrical connection receiving portions 141 and 141 protruding upward.
142 and an end wall 102a for closing the end of the cylinder hole 103
And output ports 113 and 114 corresponding to the pressure chambers 106 and 107 respectively. A plug 115 is fitted in a liquid-tight manner at one end of the cylinder hole 103 and is prevented from coming off by a snap ring 116. And each connection receiving section 14
1, 142, connecting portions 119a, 119 of the reservoir 119;
b are fitted via seal members 140, respectively. In addition, the cylinder body 101 is
Liquid passages 110 and 111 extending in the radial direction are provided on the inner surface of the peripheral wall of each of the 06 and 107 and communicate with the connecting portions 119a and 119b of the reservoir 17.

The primary piston 104 and the secondary piston 105 are provided with slits 120,
Pins 122, 123 fixed to the cylinder body 101 along the diameter direction pass through the slits 120, 121, respectively.
Liquid passages 124 and 125 are opened in the center of the front end portion further forward. The primary piston 104 and the secondary piston 105 are provided with a return spring 126 and an end wall 1 of the cylinder body 101 disposed therebetween.
02a is biased in the direction of the non-operation position (rightward in FIG. 15) by a return spring 127 disposed between the return spring 127a and the return spring 02a.

A center valve 130 is provided at the tip of each of the pistons 104 and 105. This center valve 1
Since 30 is the same for each of the pistons 104 and 105, only one will be described. Center valve 130
As shown in FIG. 16, an annular valve seat member 131 made of an elastic material fitted to the piston 105 and a rod 13
And a piston-like valve body 133 integrally having
And a conical spring 135 disposed between the retainer 134 fixed to the end of the valve 05 and the flange-shaped valve body 133, and the conical spring 135 urges the flange-shaped valve body 133 in a direction of seating on the valve seat member 131. are doing. The rod 132 passes through the valve seat member 131 and the liquid passage 125, and the rear end of the rod 132 is a pin 1.
23.

The primary pressure chamber 106 includes the piston 10
4, the fluid passage 110 formed in the cylinder body 101, the floating throttle valve mechanism 143, the reservoir 1
It can communicate with the reservoir 119 via the 19 connection portions 119a. The secondary pressure chamber 107 has a piston 105
The liquid passage 125 at the tip, the liquid passage 111 formed in the cylinder body 101, the floating throttle valve mechanism 143, the connecting portion 119b
Can communicate with the reservoir 19 via the The two pressure chambers 106 and 107 communicate with front and rear wheel cylinders (not shown) through corresponding output ports 113 and 114 formed in the cylinder body 102, respectively.

The floating throttle valve mechanism 143, 143
As shown in the figure, a valve seat 144 formed at the tip of the connection portion 119a, 119b, and a valve chamber 145 defined by the connection portion 119a, 119b in each of the connection receiving portions 141, 142 are provided. The floating valve body 146 is accommodated therein. Usually, the floating throttle valve mechanism 143 is connected to the cylinder body 101 of the master cylinder 100 in which the connection portions 119a and 19b of the reservoir 119 are fitted.
Are provided in the liquid passages in the connection receiving portions 141 and 142, respectively, but are not limited to this as long as they are on the hydraulic fluid replenishment passage from the pressure generating chambers 106 and 107 to the reservoir 119.

The floating valve body 146 is made of an elastic material, for example, a synthetic rubber material, has a throttle hole 146b at the center thereof, and has a disk shape having an outer diameter larger than the outer diameter of the distal end portions of the connecting portions 119a and 119b. The valve body has a valve portion 146c formed obliquely upward along the outer periphery. The connection part 11
The distal ends of 9a and 119b abut the floating valve body 146 floating in the valve axis direction, and have a through groove 119c at the distal end in the radial direction. And the reservoir 1
19, a connecting portion 119a with the cylinder body 101,
119b and the cylinder body 10 of the connecting portion.
When the floating valve element 146 moves to the reservoir 119 side, the valve portion 146c abuts on the inner peripheral surface of the valve chamber 145 between the cylinder body 101 and the cylinder body 101.
A seat surface 147 having a partly inclined surface with respect to the valve shaft is formed so as to open when moving to the side.

When the operation of the master cylinder 100 is started, in FIG. 17, when the hydraulic fluid flows from the lower side to the upper side, that is, when the hydraulic fluid flows from the pressure chambers 106 and 107 to the reservoir 119, the floating throttle valve mechanism 143 is turned off. The flow of the hydraulic fluid causes the floating valve body 146 to float and abut against the valve seat 144 to close the valve, thereby acting to flow the hydraulic fluid upward only through the throttle hole 146b. Therefore, at the start of operation, the amount of hydraulic fluid that escapes from the pressure chambers 106 and 107 to the reservoir 119 can be reduced.

Conversely, as shown in FIG. 18, from the upper side to the lower side,
That is, the pressure chambers 106 and 107 are
When there is a flow of the hydraulic fluid to the floating valve body 146, the floating valve body 146 descends and separates from the valve seat 144 due to the flow of the hydraulic fluid and its own weight, and the inclination of the floating valve body 146 The valve portion 146c is connected to the seat surface 147.
, And the valve 119 is opened, and the hydraulic fluid in the reservoir 119 flows between the valve seat 144 and the floating valve element 146, and between the valve element 146 and the floating valve element 146.
To flow to the lower pressure chambers 106 and 107 through the outside of the pressure chamber. Therefore, the master cylinder 100
When the pressure returns, the hydraulic fluid in the reservoir 119 can be replenished to the pressure chambers 106 and 107 without resistance (low resistance).

As in the case of releasing the traction control device and the vehicle stability control device shown in FIG.
When the amount of the hydraulic fluid returned from the lower side to the upper side, that is, from the pressure chambers 106 and 107 of the master cylinder 100 to the reservoir 119 is large, the valve closes as described above due to the large flow of the hydraulic fluid. The valve portion 146c of the valve body 146 is pushed and bent away from the seat surface 147 (elastically deformed) by the pressing force of the flow of the hydraulic fluid, and the passage is enlarged, while the passage at the distal end portion of the connection portion 119a, 119b is enlarged. It acts to flow upward through the groove 119c. Therefore, the hydraulic fluid is returned to the reservoir 19 without resistance (low resistance). In addition, the floating valve element 146 is provided in FIG.
As shown in FIG. 7, a small urging force may be applied upward by the compression spring 148.

Note that the technique of the present invention is not limited to the technique in the above-described embodiment, but may be implemented by means of another embodiment having the same function. Can be changed or added.

[0058]

As is apparent from the above description, according to the master cylinder of the present invention, when the piston is operated, the throttle function for restricting the flow of the hydraulic fluid from the pressure generating chamber to the reservoir is provided.
When the piston returns, a valve function that opens to allow the flow of hydraulic fluid from the reservoir to the pressure generating chamber, and a relief valve that allows a large amount of hydraulic fluid to flow from the pressure generating chamber to the reservoir Since a throttle valve mechanism having a function is disposed in the liquid passage, the vehicle includes a traction control device and a vehicle stability control device,
Simple and non-large valve structure that can reduce the amount of hydraulic fluid that escapes to the reservoir at the start of operation of the master cylinder and can quickly respond to hydraulic pressure fluctuations when the traction control device or the vehicle stability control device is released Is provided. At the same time, the invalid stroke of the piston of the master cylinder can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a master cylinder of the present invention.

FIG. 2 is an enlarged cross-sectional view of a throttle valve mechanism provided at a connection portion between a cylinder body and a reservoir in FIG. 1 in a closed state.

FIG. 3 is a bottom view showing a floating valve body of the throttle valve mechanism of FIG. 2;

4 is a cross-sectional view of the throttle valve mechanism of FIG. 2 in an open state.

FIG. 5 is a cross-sectional view of the throttle valve mechanism of FIG.

FIG. 6 is an enlarged cross-sectional view of a throttle valve mechanism in a valve closed state according to a second embodiment of the master cylinder of the present invention.

FIG. 7 is a bottom view of the throttle valve mechanism of FIG. 6;

8 is a cross-sectional view of the throttle valve mechanism of FIG. 6 in an open state.

FIG. 9 is a cross-sectional view of the throttle valve mechanism of FIG. 6 in a valve-opened state with hydraulic fluid.

FIG. 10 is an enlarged sectional view of a throttle valve mechanism of a third embodiment of the master cylinder of the present invention in a valve-closed state.

FIG. 11 is a bottom view of the throttle valve mechanism of FIG. 10;

FIG. 12 is an enlarged sectional view of a portion A in FIG. 10;

13 is a cross-sectional view of the throttle valve mechanism of FIG. 10 in an open state.

FIG. 14 is a cross-sectional view of the throttle valve mechanism of FIG. 10 in a valve-opened state by a hydraulic fluid.

FIG. 15 is a longitudinal sectional view of a master cylinder and a reservoir, showing a fourth embodiment of the master cylinder of the present invention.

FIG. 16 is an enlarged sectional view of a center valve in the master cylinder of FIG.

17 is an enlarged cross-sectional view of a throttle valve mechanism provided at a connection portion between a cylinder body and a reservoir in FIG. 15 in a closed state.

FIG. 18 is a cross-sectional view of the throttle valve mechanism of FIG. 15 in an open state.

FIG. 19 is a cross-sectional view of the throttle valve mechanism of FIG. 15 in a valve-opened state with hydraulic fluid.

FIG. 20 is a longitudinal sectional view of a conventional master cylinder.

[Explanation of symbols]

 19, 119 Reservoir 19a, 19b, 119a, 119b Connection 20, 100 Master cylinder 21, 101 Cylinder body 22, 102 Cylinder main body 22b, 24a, 108, 109 Liquid passage 27, 104 Primary piston 28, 105 Secondary piston 29, 106 Primary pressure chamber 30, 107 Secondary pressure chamber 31, 32, 126, 127 Return spring 33, 34, 113, 114 Output port 41, 42, 141, 142 Connection receiving part 43, 143 Floating throttle valve mechanism 44, 54, 74, 144 Valve seat 46, 146 Floating valve body 46b, 146b, 161a Restriction hole 46c, 58, 79 Slit 53 Restrictor valve mechanism with valve seat 55, 75 Rib 56, 76, 77 Valve seat 73 Restrictor with double valve seat Structure 76a Through hole (relief port) 119c Through groove 146c Valve 147 Seat surface

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shusaku Chiba 2-11-6 Shinmeicho, Higashimatsuyama-shi, Saitama F-term (Reference) 3D047 BB20 BB47 CC17 CC28 CC30 FF09 FF13 HH10 KK01

Claims (5)

[Claims] A piston is slidably disposed in a cylinder hole formed in a cylinder body, a pressure generation chamber is defined by the piston and the cylinder body, and the pressure generation chamber communicates with a reservoir to communicate with a hydraulic fluid. A master cylinder which has a liquid passage for replenishing the pressure generating chamber with the pressure generating chamber and discharges a hydraulic fluid pressurized in the pressure generating chamber to an output port when the piston operates. A throttle function to throttle the flow of hydraulic fluid from the reservoir to the reservoir, a valve function to open the valve when the piston returns, and to allow the flow of hydraulic fluid from the reservoir to the pressure generation chamber; A master cylinder, wherein a throttle valve mechanism having a relief valve function for allowing a flow of hydraulic fluid to the reservoir is provided in the fluid passage. 2. The throttle valve mechanism according to claim 1, wherein the throttle valve mechanism has a valve seat provided at a distal end of a connection portion of the reservoir with the cylinder body, a valve seat surface seated on the valve seat, a throttle hole, and a substantially central portion. The master cylinder according to claim 1, wherein the master cylinder is a floating throttle valve mechanism including a floating valve body made of an elastic material and having a plurality of slits formed therein. 3. The throttle mechanism is formed at a distal end of a connecting portion between a thin plate-shaped or thin film-shaped valve seat made of an elastic material and the cylinder body of the reservoir, and the valve seat is provided on the pressure generating chamber side. And a locking portion for locking the valve seat, and in an ordinary state where the valve seat is not deformed, an outer peripheral edge of the valve seat and an inner peripheral surface of a tip of the connecting portion of the reservoir. Between
The master cylinder according to claim 1, wherein a slit for restricting is formed. 4. The throttle mechanism according to claim 1, wherein the large-diameter and small-diameter thin plate-shaped or thin-film-shaped valve seats made of an elastic material are interposed between the large-diameter valve seat and the small-diameter valve seat. A rib formed at the distal end of a connection portion of the reservoir with the cylinder body for contacting from the pressure generating chamber side, and a locking portion for locking the two valve seats at a substantially central portion. A through-hole is formed in a portion of the large-diameter valve seat surface that overlaps the small-diameter valve seal, and the outer periphery of the large-diameter valve seat and the reservoir are formed in a normal state where the large-diameter valve seat is not deformed. The master cylinder according to claim 1, wherein a slit for restricting is formed between the connecting portion and the inner peripheral surface of the connecting portion. 5. The throttle mechanism has a floating valve body made of an elastic material having a throttle hole formed therein, and a valve seat for contacting the floating valve body floating in the valve axis direction, and has a penetrating end. The floating valve element moves toward the reservoir on the inner peripheral surface of the valve chamber, which has a groove, and is connected to the distal end of the reservoir with the cylinder body, and is a passage between the connection part and the cylinder body. 2. A floating throttle mechanism comprising a seat surface inclined with respect to the valve shaft so as to close when the valve is closed and to open when moving to the cylinder body side. Master cylinder described in 1.