JPS635980Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a control valve for a brake oil exchange device used in a brake oil exchange device that extracts obsolete brake oil from the hydraulic brake circuit of automobiles, railway vehicles, etc. and replaces it with new brake oil. It is something.

Brake oil is replaced by draining old brake oil from the outlet of the hydraulic brake circuit and then supplying new brake oil from the master cylinder. However, since air bubbles are generated when new brake oil flows into the emptied hydraulic brake circuit, the first portion of the new brake oil containing air bubbles must be drained out of the hydraulic brake circuit. For this reason, in the past, workers visually checked the condition of the brake oil flowing out from the vinyl hose connected to the discharge valve of the hydraulic brake circuit, and confirmed that the discharge of old and dirty brake oil was completed and that the brake oil containing air bubbles was leaking. At the end, confirm that new brake oil that does not contain air bubbles has started flowing out, and the worker who presses the brake pedal notifies the worker visually checking the condition of the brake oil when the brake pedal is pressed. The work was carried out by opening the discharge valve of the brake cylinder only when pressure was applied to prevent discharged brake oil from flowing back into the hydraulic brake circuit. However, this conventional method requires a skilled worker, is time consuming, and has low work efficiency. , a control valve consisting of an oil discharge pipe that can be connected at one end to a brake cylinder of a vehicle, and a movable valve that slides in the valve chamber in accordance with the oil flow resistance in the middle part of the oil discharge pipe. proposed a brake oil exchange system equipped with a brake oil exchange system, but there is no control valve for this type of brake oil exchange system that is optimal for this system. Development was necessary.

The present invention was completed with the aim of providing a control valve for a brake oil exchange device developed in view of the above-mentioned circumstances, and will be described in detail below with reference to illustrated embodiments.

As is well known, in a vehicle A, such as an automobile, in which oil is to be changed, a piston 2 of a master cylinder 1 is moved forward and backward by depression of a brake pedal 3, and pressure oil is sent to a brake cylinder 4 from an oil supply cup 18. . An oil discharge pipe 6 is connected at one end to each brake cylinder 4 via a discharge valve 42 so as to be easily attachable and detachable. A control valve A for a brake oil exchange device is provided. A main flow path 6a and a bypass flow path 6b are formed at the front end of this oil discharge pipe 6, and the main flow path 6a includes a pump 8 driven by a motor 7, a pressure switch 10, and a needle valve 9. On the other hand, a check valve 11 is provided in the bypass flow path 6b. In addition, the control valve 1 is normally operated by the elastic force of the spring 14.
3 is pressed against the seat portion 15 on the inlet side, and the brake cylinder 4 and the discharge end 16 of the oil discharge pipe 6 are
communication with is cut off. Further, the brake pedal 3 is automatically pressed by a pedaling device 17 that repeatedly presses the brake pedal 3. Here, to explain the control valve I according to the present invention in detail, 5 is a cylinder that forms the main body of the control valve I, and at one end of the cylinder 5 is a thin cylinder 28 that connects with a discharge pipe. Screw on the tip and attach the protruding part to the discharge pipe connection part 5.
a, and the base end surface of the narrow cylinder 28 located inside the cylinder 5 is formed into a seat part 28', and
A flange portion 5' is provided at the other end of the cylinder 5, and the inner surface of the narrow opening provided at the other end is connected to the seat portion 1.
5, and the sheet portion 15 and the sheet portion 2
A spherical movable valve 13, which is elastically supported by a spring 14 whose one end is supported by a step on the inner surface of a narrow cylindrical body 28, is loosely fitted into the valve chamber 12 formed between the valve chamber 12 and the valve chamber 12 through a gap 12'. . 31 is brake cylinder 4
This is a discharge valve connection portion of the brake cylinder provided at the other end of the cylinder body 5 to connect to the discharge valve 42 of the cylinder body 5, and the discharge valve connection portion 31 is slidably fitted into the flange portion 5' side of the cylinder body 5. The tip to be installed is connected to the short cylindrical part 32.
an outer cylindrical body 33 formed in the form of a cylindrical body 33; a spring 35 having one end supported by a retaining ring 34 provided on the inner surface of the lower end and the other end supported by a flange portion 5' of the cylindrical body 5 to spring the outer cylindrical body 33; , slide grooves 36, 36 provided oppositely on both sides of the base of the short cylindrical portion 32.
a tapered edge 37' that is engaged with and guided to slide;
It consists of a slide plate 38 in which a slide hole 37 with 37' is transparent, and the tapered edge 37' of the slide hole 37 of the slide plate 38,
37' is the short cylindrical part 32 through the slide grooves 36, 36.
It is designed to penetrate into the interior of the brake cylinder and lock the discharge valve 42 of the brake cylinder regardless of the difference in its outer diameter. In addition, in the figure, 39 is a retaining ring of the slide plate 38, 40 is a seal plate with a hole attached to the cylinder 5, and 41 is a pull portion provided vertically at the front and rear of the slide plate 38.

In a vehicle constructed in this way, when replacing the brake oil, it is first necessary to remove the old brake oil. For this purpose, after sliding the slide plate 38 so that the tapered edges 37', 37' of the slide hole 37 are at approximately the same position as the inner diameter of the short cylinder part 32, the discharge valve 42 of the brake cylinder 4 is inserted into the cylinder. The slide plate 3 is pressed against the seal plate 40 of the body 5, and then the outer cylinder body 33 is pushed up against the elastic force of the spring 35.
8 in the opposite direction to the above, and the tapered edges 37 of the slide hole 37 are inserted into the inner surface of the short cylindrical portion 32 so that the tapered edges 37 of the slide hole 37 are inserted into the stepped portion of the discharge valve 42. ', 37' and then release the push-up of the outer cylinder 33, the outer cylinder 33 descends due to the elastic force of the spring 35 and closes the discharge valve 4.
2, the control valve A is connected to the discharge valve connection part 31.
It is connected to the discharge valve 42 with a. Next, the pump 8 is operated to suck the brake oil in the hydraulic brake circuit through the brake cylinder 4 and the oil discharge pipe 6 and discharge it through the discharge end 16 thereof. At this time, the pressure inside the valve chamber 12 of the cylindrical body 5 is lower than that of the inlet hole of the cylindrical body 5 connected to the discharge valve 42, so this differential pressure causes the spherical movable body to be resiliently supported by the spring 14. Valve 13 is spring 1
It slides downward against the elastic force of 4 and leaves the seat portion 15, thereby communicating the oil discharge pipe 6 and the hydraulic brake circuit. If the brake oil should flow backward during this suction operation, the movable valve 13 will come into contact with the seat portion 15 of the cylindrical body 5 and close the conduit. The gap 12' between the movable valve 13 and the valve chamber 12 also functions as a fixed orifice circuit during the suction operation to maintain the suction pressure at a constant value. If there are multiple brake cylinders 4, these brake cylinders 4
This function as a fixed orifice circuit is particularly effective when simultaneously sucking brake oil from the brake cylinder 4, and even after one brake cylinder 4 is emptied, suction from the other brake cylinder 4 continues. , the brake oil of the entire hydraulic brake circuit is completely drained. When the discharge of the old brake oil is completed in this way, the main flow path 6a, which is the piping on the discharge side of the pump 8, which had been exhibiting high pressure due to the action of the needle valve 9,
Since the internal pressure drops rapidly, this pressure change is detected by the pressure switch 10, and the pump 8 is stopped, an indication indicating completion of extraction is issued, and at the same time, a signal is issued instructing the start of filling with new brake oil. Filling with new brake oil is started by supplying new brake oil to the oil supply cup 18 of the master cylinder 1 from the oil supply passage 19. A switching valve 20 is provided in the oil supply passage 19, and works in conjunction with a liquid level gauge 21 attached to the oil supply cup 18 to maintain a constant level of the liquid level in the oil supply cup 18. New brake oil is in the refueling cup 18
When the predetermined amount is filled, the brake pedal 3 is forcibly pressed repeatedly in order to fill the hydraulic brake circuit with the predetermined amount. For this purpose, a pedaling device 17 as shown in FIG. 3 is provided. The pedaling device 17 shown in the illustrated embodiment is composed of an air cylinder 22, a cylinder switching valve 23, cylinder back pressure detection valves 24, 25, etc. In the illustrated state, compressed air is supplied to the cylinder switching valve 23 through the valve 26. Then, compressed air enters the right end of the air cylinder 22, and the piston 27 moves forward to the left to press the brake pedal 3. When the brake pedal 3 is pressed to its limit in this way, the piston 2
7 stops, but as the piston 27 stops, the back pressure of the piston 27 drops to near atmospheric pressure, which is detected by the cylinder back pressure detection valve 24.
Switch the cylinder switching valve 23. As a result, the piston 27 returns to the right, that is, to the rear, but stops at the end of the stroke, so the cylinder back pressure detection valve 25 detects the resulting drop in back pressure and switches the cylinder switching valve 23 again. In this way, the brake pedal 3 is automatically and repeatedly pressed. By repeatedly pressing the brake pedal 3 in this way, the piston 2 of the master cylinder 1 sequentially supplies new brake oil in the oil supply cup 18 into the hydraulic brake circuit, and the new brake oil is supplied in accordance with the amount of supply. Brake oil is automatically replenished from the oil supply path 19. The hydraulic brake circuit is thus filled with new brake oil, and as mentioned at the beginning, the brake oil containing air bubbles overflows from the oil discharge pipe 6 through the cylinder 5 and the bypass passage 6b. To explain the operation of the control valve A in this case, the cylindrical body 5 has a spherical movable valve 13 having a smaller diameter than the inner diameter of the valve chamber 12 loosely fitted inside the valve chamber 12 through a gap 12', and a spring 14. As shown in FIG. 1, the movable valve 13 is normally pressed against the seat portion 15 on the inlet side by the force of the spring 14. However, when new brake oil fills the hydraulic brake circuit and the pressure applied by the piston 2 of the master cylinder 1 is transmitted to the brake oil in the inlet hole of the cylinder 5, the pressure of the brake oil resists the force of the spring 14 and the movable valve 13 is moved downward from the seat portion 15, and new brake oil containing air bubbles flows into the oil discharge pipe 6.
At this time, since the pump 8 is stopped, the brake oil flows to the discharge end 16 through the check valve 11 of the bypass passage 6b. While the brake oil containing air bubbles is flowing in this way, the movable valve 1 is closed as shown by the dashed line in Fig. 2.
3 is seat part 1 due to brake oil flow resistance.
It is kept at a position slightly apart from 5. Note that when the piston 2 of the master cylinder 1 returns, the pressure inside the hydraulic brake circuit is reduced, so the movable valve 13 returns to the position shown in FIG. 1 by the force of the spring 14.
It prevents backflow and maintains a negative pressure inside the hydraulic brake circuit, thereby reducing the generation of air bubbles and facilitating the filling of new brake oil. When the brake oil containing air bubbles is discharged from the oil discharge pipe 6 in this manner, the inside of the hydraulic brake circuit is filled with brake oil that does not contain air bubbles, and the brake oil overflows through the cylinder 5. . However, brake oil that does not contain air bubbles has a higher apparent density than brake oil that contains air bubbles, and the movable valve 13 receives a large flow resistance and resists the force of the spring 14 as shown by the two-dot chain line in FIG. It is pressed against the sheet portion 28' on the outlet side and blocks the flow. Therefore, the cylindrical body 5 has the function of allowing brake oil containing air bubbles to pass therethrough, but automatically blocking brake oil that does not contain air bubbles to prevent unnecessary leakage. As the air bubbles in the hydraulic brake circuit decrease, the stroke of the piston 2 of the master cylinder 1 gradually becomes smaller, and when the hydraulic brake circuit reaches a state filled with bubble-free brake oil, the stroke of the piston 2 decreases. is a constant stroke determined by the position of the communication hole 29 with the oil supply cup 18. The stroke of this piston 2 is detected by the stroke detector 30 of the pedaling device 17,
When the stroke reaches a certain level, it is assumed that the filling process with new brake oil has been completed and the operation of all devices is stopped. In addition, as mentioned above, the pedaling device 17
When the piston 27 of the air cylinder 22 stops, it detects a change in the back pressure and switches the cylinder switching valve 23, so when the stroke of the piston 2 gradually decreases and as a result, the stroke of the brake pedal 3 gradually decreases. Also, it is possible to repeat the reciprocating motion while following the change in the stroke of the brake pedal 3. In the manner described above, the removal of old brake oil and the filling of new brake oil are performed fully automatically. In addition, the cylindrical body 5
Of course, the structure of the discharge pipe connecting portion 5a provided at one end of the drain pipe is not limited to that of the embodiment described above.

As is clear from the description of the above embodiments, the present invention has seat parts formed at both ends of the valve chamber, which is normally pressed against the seat part on the inlet side, but which slides depending on the magnitude of the oil flow resistance. A discharge pipe connection part is provided at one end of the cylinder in which a spherical movable valve is loosely fitted, which is held in a state pressed against the seat part on the exit side and in an intermediate state separated from both seat parts, and a brake cylinder is provided at the other end. Because it has a specially constructed discharge valve connection part that connects to the discharge valve of
The short cylindrical part of the outer cylinder constituting the discharge valve connection part is connected to the discharge valve of the brake cylinder through engagement with a slide plate, and the oil discharge pipe is connected to the discharge pipe connection part at one end. Therefore, the brake oil can be replaced efficiently by simply pressing the brake pedal repeatedly while filling the hydraulic brake circuit with new brake oil. Utilizing the difference in flow resistance between brake fluids containing air bubbles, it is possible to allow only the former to pass through first, and when the brake oil containing air bubbles has finished flowing out, the pipe can be automatically shut off. It is suitable for a brake oil exchange device that can completely automatically change the brake oil without requiring any monitoring work by a worker. Since the connection part consists of an outer cylinder with a short cylinder part, a spring that snaps this into the other end of the cylinder, and a slide plate with a slide hole, the diameter of the discharge valve of the brake cylinder Combined with the advantage that the connection to the discharge valve can be made accurately and easily even if the values are slightly different, the practical value is extremely great.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view of the same, and FIG. 3 is a circuit diagram of a brake oil exchange device using the present invention. 5... Cylindrical body, 5a... Discharge pipe connection part, 12...
Valve chamber, 13... Spherical movable valve, 14... Spring, 15... Seat part on the inlet side, 28'... Seat part on the outlet side, 31... Discharge valve connection part, 32...
Short cylinder part, 33...outer cylinder body, 35...spring,
36...Slide groove, 37...Slide hole, 3
7'...Tapered edge, 38...Slide plate.

Claims (1)

[Scope of utility model registration request] One end of the valve chamber 12 in the cylindrical body 5 provided with the discharge pipe connection part 5a at one end is formed as the seat part 15 on the inlet side, and the other end is formed as the seat part 28' on the outlet side,
Further, in the valve chamber 12, a spring 14 is normally resiliently supported by a seat part 15 on the inlet side, but depending on the magnitude of oil flow resistance, it slides and is pressed against a seat part 28' on the outlet side. A spherical movable valve 13 is loosely fitted therein and held in an intermediate state away from both seat portions 15 and 28', and an outer member having a short cylindrical portion 32 at the other end is fitted loosely into the cylindrical body 5. The cylindrical body 33 is slidably fitted under the spring 35, and the short cylindrical portion 32 is fitted with a slide plate 3.
8 is slidably fitted into the slide hole 37 through the slide hole 37, and the tapered edges 37', 37' formed at the edge of the slide hole 37 are opposed to the base of the short cylindrical portion 32. A control valve for a brake oil exchange device, characterized in that the control valve is engaged with slide grooves 36, 36 provided in the same manner.