JPH0129750B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a master cylinder of different diameters used in automobiles, etc., and in particular, a master cylinder of different diameters in which a pressure control valve is provided between a hydraulic chamber and a reservoir of the master cylinder of different diameters. This relates to a quick-filling master cylinder.

[Prior Art] A conventional quick-filling master cylinder of this type is, for example, as shown in Japanese Patent Laid-Open No. 57-22949, in which a piston of a different diameter is fitted into a cylinder hole of a different diameter in a fluid-tight and movable manner. A valve chamber is interposed in a fluid passage that communicates both hydraulic pressure chambers and a reservoir, and a flat first valve chamber is provided at the bottom of the valve chamber to define a small hydraulic pressure chamber and a large diameter hydraulic chamber. A first valve body forming a valve seat and seated on the first valve seat is provided at the bottom of the bell-shaped valve case, and a spherical second valve body is seated on a second valve seat around the opening at the top of the valve case. A pressure control valve, which is housed in a valve case, is disposed within the valve chamber, and the first valve body is biased by a valve spring in a direction opposite to the reservoir and is seated on the first valve seat. There is a known valve in which the first valve element is moved away from the second valve seat to allow the hydraulic fluid to flow toward the reservoir, and the second valve element is moved away from the second valve seat to allow the hydraulic fluid to flow in the opposite direction to the reservoir. It is being

[Problem to be solved by the invention]

However, in the pressure control valve of the quick-filling master cylinder configured in this way, the first valve body that allows flow toward the reservoir is formed in a planar shape at the bottom of the valve case. If an imbalance occurs in the valve spring that biases the valve in the direction away from the reservoir, causing the entire valve to tilt, there is a risk that prompt valve operation and reliable sealing may be prevented.

In addition, there were also problems in manufacturing, such as the need for advanced technology to form a ring-shaped high-precision sealing surface on the first valve seat or the first valve body of the pressure control valve.

The present invention has been made in view of the above points, and an object of the present invention is to provide a quick-filling master cylinder equipped with a pressure control valve that provides accurate valve operation and reliable sealing, and is easy to manufacture.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a piston of different diameters having a small diameter head and a large diameter head in a modified master cylinder having a small diameter cylinder hole and a large diameter cylinder hole connected in series. It is fitted in a fluid-tight and movable manner, and defines a small-diameter side hydraulic chamber in the small-diameter cylinder hole in front of the small-diameter head, and a large-diameter side hydraulic chamber between the rear of the small-diameter head and the front of the large-diameter head, and a reservoir. A valve chamber is interposed in the liquid passage between the two hydraulic pressure chambers, and a first valve body is pressed into contact with a first valve seat at the bottom of the valve chamber by a valve spring within the valve chamber, and the hydraulic pressure chamber moves toward the reservoir. a first valve part that allows flow; a bell-shaped valve case that is locked to the first valve body and has an opening at the top and a second valve seat around the opening; Second
In a quick-filling master cylinder equipped with a pressure control section that includes a second valve body that is seated on a valve seat and that allows flow in an anti-reservoir direction, the pressure control valve has a first valve The body of the body is integrally fitted into the bubble case of the second valve part, and the first valve body has a communication hole passing through the body in the axial direction and a flange-like part at the bottom of the body. A valve spring receiving part formed in the above, a guide part formed on the outer periphery of the valve spring receiving part so as to extend so that the tip thereof is guided in contact with the peripheral wall of the valve chamber, and a part of the peripheral edge of the guide part formed by notching the guide part. and a hemispherical valve head formed near the guide portion around the opening end of the communication hole.

[Embodiment] Next, an embodiment in which the rapid filling type master cylinder according to the present invention is applied to a tandem type master cylinder will be described based on the drawings.

The cylinder body 1 has a small-diameter cylinder hole 2 and a large-diameter cylinder hole 3 whose one end is open at the rear thereof. The piston 4 is fluid-tightly and movably inserted through cup seals 4c and 4c respectively ringed on both heads 4a and 4b.
A first hydraulic pressure chamber 6 on the small diameter side is defined between the cylinder bottom 1a and the head 4a.

Further, a piston 5 of different diameters having a small diameter front part 5a and a large diameter rear part 5b is arranged, with the small diameter front part 5a disposed in the small diameter cylinder hole 2 and the large diameter rear part 5b in the large diameter cylinder hole 3. The second small-diameter side is fitted between the small-diameter head portions 5a of the small-diameter piston 4 and the different-diameter piston 5 by liquid-tightly and movably fitted with cup seals 5c, 5c ringed in the parts 5a, 5b, respectively.
A hydraulic pressure chamber 7 is defined, and a large diameter side hydraulic pressure chamber 8 is defined between the small diameter front end 5a and the large diameter rear end 5b of the different diameter piston 5. A small diameter opening 5a is provided with a pore 5e that communicates both the hydraulic chambers 7 and 8, and is normally closed with a cup seal 5c.

Furthermore, a first return spring 9 for biasing the small diameter piston 4 in the anti-braking direction is contracted in the small diameter first hydraulic pressure chamber 6, and a first return spring 9 is compressed in the small diameter first hydraulic pressure chamber 6.
A second return spring 10 is compressed inside.

Further, the first hydraulic pressure chamber 6 on the small diameter side has a first discharge port 11 for delivering pressurized liquid to the wheel cylinder (not shown) of the rear wheel, and the second hydraulic pressure chamber 7 on the small diameter side has a first discharge port 11 for delivering pressurized liquid to the wheel cylinder (not shown) of the rear wheel. Second discharge ports 12 are respectively provided for delivering pressurized fluid to wheel cylinders (not shown).

Furthermore, a reservoir attachment boss portion 13 is integrally formed on the upper side of the cylinder body 1, and a reservoir 14 is externally fitted onto the boss portion 13 and fixed with a band 15.

Also, inside the reservoir attachment boss portion 13, a first distillation chamber 13b and a second distillation chamber 13 are separated by a partition wall 13a.
A relief port 16 and a supply port 17 are formed at the bottom of the first distillation chamber 13b.

A thick ridge portion 1 extends from the reservoir mounting boss portion 13 toward the rear of the cylinder body 1.
8 is formed with a liquid passage 19 penetrating from its end surface 18a to the second liquid storage chamber 13c of the reservoir attachment boss portion 13, and its open end is sealed by a steel ball 18b.

A valve chamber 20 is formed in the liquid passage 19, and a spherical first valve seat 2 corresponding to a hemispherical valve head 24g of a pressure control valve 23, which will be described later, is provided at the bottom of the valve chamber 20.
0a is formed, and in the center of the first valve seat 20a,
A first liquid passage hole 21 is opened at a position communicating with the second hydraulic pressure chamber 7 on the small diameter side when the different diameter piston 5 returns to the backward position. A second liquid passage hole 22 communicating with the chamber 8 is provided.

Further, a pressure control valve 23 is disposed within the valve chamber 20, and the pressure control valve 23 is composed of a first valve portion 24 and a second valve portion 25.

The first valve portion 24 includes a first valve body 24a made of synthetic resin.
An axial communication hole 24c is provided in the body portion 24b, and a flanged valve spring receiving portion 24d is formed in the lower part of the body portion 24b.
A guide portion 24e in contact with the peripheral wall 20b of 0 is extended, a part of this guide portion 24e is cut out to form a liquid passage portion 24f, and a valve chamber is formed around the communication hole 24c on the lower surface of the valve spring receiving portion 24d. A hemispherical valve head 24g liquid-tightly abuts the first valve seat 20a which is recessed into a spherical shape of 20; It forms a plurality of tapered grooves 24h that serve as liquid passages when seated on the second valve seat, and is activated when the valve head 24g seated on the first valve seat 20a leaves the first valve seat 20a. The liquid is allowed to flow in the direction of the reservoir 14.

Further, the second valve portion 25 has an opening 2 at the top of the spherical surface.
5a and a metal bell-shaped valve case 25c with a flange portion 25b formed at the bottom.
and a second valve body 25d, which is a spherical float valve built into the valve case 25c.The second valve body 25d, which is seated on a second valve seat formed around the opening 25a, By moving away from the valve seat, the hydraulic fluid is allowed to flow in a direction opposite to the reservoir.

Then, the body portion 24b of the first valve body 24a is fitted into the valve case 25c, and the first valve portion 24 and the second valve body 24b are fitted into the valve case 25c.
The pressure control valve 23 is constructed by integrally incorporating the valve portion 25.

The pressure control valve 23 is arranged within the valve chamber 20,
Female threaded portion 20c formed on the upper opening side of the valve chamber 20
The end surface 26b of the valve holding bolt 26 is screwed into the valve holding bolt 26 liquid-tightly through the packing 26a, and the first valve body 2
4a valve spring receiving part 24d and valve case 25
The valve spring 27 is compressed between the valve spring 27 and the overlapping part of the flange part 25b of the valve body 25c, so that under normal conditions, the valve head 24g of the first valve body 24a liquid-tightly contacts the first valve seat 20a to close the valve. It is located in Sho 25
e is an orifice formed on the side wall of the valve case 25c.

Also, the reservoir 14, the first liquid reservoir chamber 13b, the second liquid reservoir chamber 13c, the liquid passage 19, the valve chamber 20, the relief port 16, the supply port 17, the first liquid passage hole 21, the second liquid passage hole 22, the small diameter The first hydraulic pressure chamber 6 on the side, the second hydraulic pressure chamber 7 on the small diameter side, and the hydraulic pressure chamber 8 on the large diameter side are filled with hydraulic fluid.

Next, the operation of this embodiment configured as described above will be explained.

The cylinder body 1 is installed in the engine room at an angle such that the working fluid level in the reservoir 14 attached to the mounting boss portion 13 is horizontal at a predetermined position. In normal state, the pressure control valve 23 disposed inside the first valve body 24
The hemispherical valve head 24g of a is in liquid-tight contact with the first valve seat 20a formed at the bottom of the valve chamber 20 by the action of the valve spring 27, and the opening 25a of the second valve part 25
is closed by the second valve body 25d which receives the buoyancy of the hydraulic fluid.

When the brake pedal or the like is operated for braking, a push rod (not shown) whose tip is inserted into the fitting recess 5d of the different diameter piston 5 is moved forward, thereby pushing the different diameter piston 5 and the small diameter piston 4 and moving the large diameter side. The pressure inside the hydraulic pressure chamber 8 is increased to a higher pressure than the inside of the second hydraulic pressure chamber 7 on the small diameter side, and the pressure liquid inside the large diameter side hydraulic pressure chamber 8 is passed through the small hole 5e provided in the small diameter front part 5a. from the back of the cup seal 5c and from the second liquid passage hole 22 to the first
The liquid is supplied to the second hydraulic pressure chamber 7 on the small diameter side via the liquid passage hole 21 .

The pressure inside the small-diameter second hydraulic chamber 7 supplied with pressure liquid from the large-diameter hydraulic pressure chamber 8 is rapidly increased, and the second discharge port 12
The supply of pressurized fluid to the wheel cylinder (not shown) of the front wheel is started.

At this time, the pressure control valve 2 disposed in the valve chamber 20
The first valve part 24 and the second valve part 25 of No. 3 maintain the closed state.

Further, the different diameter piston 5 moves forward and supplies the increased hydraulic pressure in the second hydraulic pressure chamber 7 on the small diameter side to the wheel cylinder of the front wheel.
After the small-diameter piston 4 in the front is pushed by the hydraulic pressure in the second hydraulic pressure chamber 7 on the small-diameter side, and the cup seal 4c of the small-diameter piston 4 closes the relief port 16, the pressure inside the first hydraulic pressure chamber 6 on the small-diameter side is pushed. Pressurized fluid is supplied from the first discharge port 11 to the wheel cylinder (not shown) of the rear wheel to quickly fill the gap between brake applications and shorten the operating time at the initial stage of braking.

When the insides of the small-diameter first hydraulic pressure chamber 6 and the second hydraulic pressure chamber 7 reach a predetermined hydraulic pressure, the pressure fluid flows from the large-diameter side hydraulic chamber 8 to the small-diameter second hydraulic pressure chamber 7. stops, and the pressure inside the hydraulic chamber 8 increases further, so the valve chamber 2
The pressure control valve 23 disposed inside the valve is opened against the valve spring 27, and a liquid passage is formed between the first valve seat 20a and the hemispherical valve head 24g, and the large diameter side liquid pressure is The pressure liquid sent out from the chamber 8 is transferred to the second liquid passage hole 22, the first liquid passage hole 21, the circulation part 24f, the valve chamber 20, and the liquid passage 19.
It is discharged to the reservoir 14 side through the.

Furthermore, when the braking operation of the brake pedal or the like reaches its maximum, the delivery of pressure fluid from the large diameter side hydraulic pressure chamber 8 is stopped, and the hemispherical valve head 24g of the first valve body 24a of the pressure control valve 23 is stopped. is again seated on the first valve seat 20a by the action of the valve spring 27 while being prevented from being eccentric and tilted by the guide portion 24e. However, at this time, if an imbalance occurs in the action of the valve spring 27, the pressure control valve 23 Even if it is tilted, the valve head 24g has a hemispherical shape, so it comes into liquid-tight contact with the first valve seat 20a, and closes the valve with a reliable seal.

Then, when the brake operation is released, the first return spring 9 and the second return spring 1
Due to the action of 0, the small diameter piston 4 and the different diameter piston 5 start retracting.

At this time, the pressure inside the large diameter side hydraulic chamber 8 is reduced,
Since the pressure is lower than that on the reservoir 14 side of the pressure control valve 23, the pressure on the second valve portion 25 of the pressure control valve 23 is
The valve body 25d is operated to open, and the opening 25a communicates to allow the flow of hydraulic fluid in the direction opposite to the reservoir, and the hydraulic fluid in the reservoir 14 is transferred to the fluid passage 19, the valve chamber 20, the opening 25a, and the communication hole 24c. , the first liquid passage hole 21 and the second liquid passage hole 22 into the large diameter side hydraulic pressure chamber 8 .

After the first liquid passage hole 21 opens into the second hydraulic pressure chamber 7 on the small diameter side, the hydraulic fluid from the reservoir 14 side is transferred from the first liquid passage hole 21 into the second hydraulic pressure chamber 7 on the small diameter side. Upon suction, the different diameter piston 5 and the small diameter piston 4 move back and return to their initial positions.

Further, when the second valve portion 25 of the pressure control valve 23 opens and the hydraulic fluid flows in the direction opposite to the reservoir, the second valve portion 25
Even if the second valve body 25d of the valve part 25 comes into contact with the upper end of the body 24b of the first valve body 24a due to the fluid pressure of the hydraulic fluid, the tapered groove 24h is formed in the upper part of the body 24b. The hydraulic fluid can flow into the hydraulic pressure chambers 7 and 8 via the tapered groove 24h.

When the small diameter piston 4 and the different diameter piston 5 return to their initial positions, the second valve portion 2 of the pressure control valve 23
The flow of hydraulic fluid from the opening 25a of 5 to the hydraulic pressure chambers 7 and 8 side is stopped, and the second valve body 25 of the second valve part 25 stops.
When d rises due to buoyancy and sits on the second valve seat,
The opening 25a is closed, and the second valve portion 25, which allows flow in the opposite direction to the reservoir, is closed.

In the above embodiment, the second valve body 25 which is a spherical float valve is attached to the second valve part 25 of the pressure control valve 23.
d, but instead of the float valve, a spherical valve or the like may be pressed against the valve seat by a spring.

[Effects of the Invention] As described above, the present invention uses a pressure control valve of a quick-filling master cylinder as a first valve portion that allows flow toward the reservoir, and has a communication hole that communicates in the axial direction and a liquid surrounding the pressure control valve. A first valve body having a flange-shaped valve spring receiving portion forming a guide portion having a passage portion, and a hemispherical valve head connected to the valve spring receiving portion and formed around a liquid passage hole. The second valve part also includes a bell-shaped valve case that has an opening at the top that allows flow in the opposite direction to the reservoir and accommodates the second valve body inside. Since the two valve bodies are integrally assembled, the guide portion of the first valve body prevents eccentricity and inclination of the pressure control valve when the pressure control valve is opened and closed. Even if the valve head is tilted and sits on the first valve seat, the spherical valve head provides reliable sealing performance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view showing one embodiment of the present invention;
FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 1...Cylinder body, 2...Small diameter cylinder hole,
3...Large diameter cylinder hole, 4...Small diameter piston, 5
...Different diameter piston, 5a...Small diameter head, 5b...
...Large diameter occiput, 6...Small diameter side first hydraulic chamber, 7...
Small diameter side second hydraulic pressure chamber, 8... Large diameter side hydraulic pressure chamber, 11...
...First discharge port, 12...Second discharge port, 13...Reservoir mounting boss portion, 14...Reservoir, 16...
Relief port, 17... Supply port, 19
...Liquid passage, 20... Valve chamber, 20a... First valve seat, 21... First communication hole, 22... Second liquid communication hole,
23...Pressure control valve, 24...First valve portion, 24a
...First valve body, 24b...Body part, 24c...Communication hole, 24d...Valve spring receiving part, 24e...Guide part, 24f...Liquid passage part, 24g...Semispherical valve head, 24h...Tapered groove, 25...Second valve portion, 2
5a...opening, 25b...flange, 25c
... Valve case, 25d ... Second valve body, 25e
... Orifice, 26 ... Presser bolt, 27 ...
Valve spring.

Claims (1)

[Claims] 1. A piston with a different diameter having a small diameter head and a large diameter head is fluid-tightly and movably inserted into an irregularly shaped master cylinder having a small diameter cylinder hole and a large diameter cylinder hole arranged in series, and the small diameter head A small-diameter hydraulic pressure chamber is defined in the front small-diameter cylinder hole, a large-diameter hydraulic chamber is defined between the rear of the small-diameter head and the front of the large-diameter head, and a valve is installed in the fluid passage between the reservoir and both hydraulic pressure chambers. A first valve part having a chamber interposed therein, and within the valve chamber, a first valve body is brought into pressure contact with a first valve seat at the bottom of the valve chamber by a valve spring to allow flow toward the reservoir due to a hydraulic pressure difference, and a first valve. A bell-shaped valve case that is fixed to the body and has an opening at the top and a second valve seat around the opening, and a second valve body that is seated on the second valve seat within the valve case. In a quick-filling master cylinder equipped with a pressure control valve having a second valve part that allows flow in a direction opposite to the reservoir, the pressure control valve connects the body of the first valve body to the bubble of the second valve part. The first valve body is integrally fitted into the case, and includes a communication hole passing through the body in the axial direction, a valve spring receiving portion formed in the shape of a brim at the lower part of the body, and a valve spring receiving portion formed in the lower part of the body. A guide portion formed on the outer periphery of the spring receiving portion so as to extend so that the tip thereof is guided in contact with the peripheral wall of the valve chamber, a liquid passage portion formed by partially notching the peripheral edge of the guide portion, and an opening of the communication hole. A quick filling type master cylinder comprising a hemispherical valve head formed near the guide portion around the end.