JPS625638Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a master cylinder inspection device for detecting flaws such as blowholes on the inner surface of a cylinder.

For example, a master cylinder is used in an automobile brake system. This master cylinder is the part that generates the required hydraulic pressure when the brake pedal is depressed, and has an oil reservoir at the top of the cylinder.
This oil reservoir and the inside of the cylinder are communicated through a supply port and a relief port.
Oil is supplied into the cylinder from the supply port,
When the brake pedal is depressed, the piston in the cylinder advances, and the cup seal attached to this piston blocks the relief port.As the piston advances further, the brake fluid in the cylinder is pressurized and the oil supply section of the cylinder ( When the check valve installed in the fluid supply passage (fluid supply passage) is pushed open, hydraulic pressure is applied to each wheel cylinder via the brake pipe, and the brake pedal is released, the piston is pushed back by the force of the return spring inside the cylinder. ing.

However, in such conventional master cylinders, since the cylinder is made by casting, blowholes sometimes occur on the inner surface of the cylinder. If there are cavities on the inner surface of the cylinder, the desired oil pressure may not be obtained or the cup seal may be damaged, so the inside of the cylinder is inspected every time. However, since this inspection is a visual inspection, it is easy to overlook defects such as blowholes, and the inspection is not only time-consuming and inefficient, but also has the drawbacks of being difficult to inspect and placing a heavy burden on the operator. Ta.

This idea was made in view of the above circumstances,
By connecting a negative pressure source and a negative pressure detection member to the recess of the piston, supplying negative pressure into the recess, and detecting the drop in negative pressure within the recess by sliding the piston within the cylinder, the casting inside the cylinder is detected. It is an object of the present invention to provide a master cylinder inspection device that can easily and reliably and automatically detect flaws such as cavities, improve work efficiency, and significantly reduce the burden on inspection workers. purpose.

An embodiment of this invention will be described below based on the drawings. In the figure, 1 is a cylinder, and one end of this cylinder 1 is closed and the other end is open. Moreover, the cylinder 1 has two cylinders spaced apart from each other on its upper part.
It has two reservoirs 2. The reservoir 2 and the inside of the cylinder 1 are communicated through a supply port 3 and a relief port 4 formed in the cylinder wall. The supply port 3 is arranged on the open end side of the cylinder 1, and the relief port 4 is arranged on the closed end side, with a slight distance from each other. Also, cylinder 1
has two oil supply sections (fluid supply passages) 5 at its bottom.
have. This oil supply section 5 is provided with a check valve 6. Further, pistons 7 and 8 are slidably provided within the cylinder 1. A primary cup (first
A cup seal) 9 and a secondary cup (second cup seal) 10 are provided, respectively.
A recess 11 is formed between these. Further, a primary cup (first cup seal) 12, a secondary cup (second cup seal) 13, and a pressure cup (third cup seal) 14 are provided at predetermined locations on the piston 8, and the primary cup 12, the secondary cup A recess 15 is formed between the holes 13. The primary cups 9 and 12, the secondary cup 1
0, 13, and pressure cup 14 are each tightly fitted into the cylinder 1. First pressure chambers 1a, 1b are formed on the cylinder closed end sides of the primary cups 9, 12. Further, a main spring 16 is interposed between the pistons 7 and 8. Further, a return spring 17 is provided between the closed end of the cylinder 1 and the primary cup 12. In addition, primary cup 9,1
2, when the pistons 7, 8 enter into the cylinder 1, the recesses 11,
15 and when the pistons 7 and 8 are returned to the cylinder opening end side by the return spring 17, the fluid in the recesses 11 and 15 is passed through the small holes provided in the pistons 7 and 8 to the first Pressure chamber 1
a, 1b. Further, the relief port 4 is located closer to the cylinder closed end than the primary cups 9, 12 when the pistons 7, 8 are returned to the cylinder open end side by the return spring 17, and is located in the first pressure chambers 1a, 1.
It is formed on the cylinder wall so as to communicate with b.

In addition, the reservoir 2 has a sealing lid 2 that can be opened and closed freely.
1 is provided. A gasket 22 is attached to the lower surface of this airtight lid 21. A second pressure chamber 23 is airtightly formed inside the airtight lid 21, and a piston 24 with a piston rod is slidably provided in the second pressure chamber 23 to form a cylinder mechanism. ing. A gasket 25 is attached to the tip of the piston rod of the piston 24, and the gasket 25 allows the relief port 4 to be opened and closed. A pneumatic source 27 is connected to the second pressure chamber 23 via a connecting pipe and a directional control valve 26 . Further, the two sealing lids 21 are connected at the same height level by a connecting bar 28, and a piston 30 of a cylinder mechanism 29 is connected to the connecting bar 28. A pneumatic source 27 is connected to the cylinder mechanism 29 via a connecting pipe and a directional switching valve 31. In addition, the airtight lid 21
A communication path 32 communicating with the inside of the reservoir 2 is formed in the reservoir 2 . A negative pressure source (vacuum pump) 35 is connected to this communication path 32 via a connecting pipe, a directional switching valve 33, and a pressure regulating valve 34. A negative pressure detection member 36 is connected to a connecting pipe between the communication passage 32 and the directional control valve 33 via a connecting pipe. In addition, 3
7 is a pressure gauge of the negative pressure source 35.

Further, an air-hydro cylinder 38 is disposed on an extension of the axis of the piston 7. The air pressure source 27 is connected to the air-hydro cylinder 38 via a connecting pipe and a directional switching valve 39.

Therefore, when inspecting the inner surface of the cylinder 1 for defects such as blowholes, first operate the negative pressure source (vacuum pump) 35 with the pistons 7 and 8 on the open end side of the cylinder 1, and press the The regulating valve 34 is adjusted to set the negative pressure of the negative pressure source 35 to a predetermined test pressure. Next, when the air pressure source 27 is opened, air flows into the directional valve 31
It flows into the cylinder mechanism 29 through the piston 30, and the piston 30 descends. Then, the sealing lid 21 is lowered via the connecting bar 28 to seal the reservoir 2. At the same time, air is supplied from the air pressure source 27 to the directional control valve 2.
6 into the second pressure chamber 23, the piston 24 descends and the gasket 25 closes the relief port 4. At the same time, air flows from the air pressure source 27 into the air-hydro cylinder 38 via the directional switching valve 39, and moves the piston therein to the rightmost end in the figure.

Next, when the directional switching valve 33 is switched, a predetermined negative pressure is supplied into the reservoir 2 via the switching valve 33, and the negative pressure is displayed on the negative pressure detection member 36. When the negative pressure in the reservoir 2 becomes stable, the directional control valve 33 is returned to its original state (the state shown in the figure).

Next, the directional switching valve 39 is switched. Then, the piston inside the air-hydro cylinder 38 moves to the left in the figure, and the piston rod presses the piston 7 inside the cylinder 1. As a result, the pistons 7 and 8 slide to the left in the figure with respect to the cylinder 1. Therefore, the air between the pistons 7 and 8 in the cylinder 1 and the air between the closed end of the cylinder 1 and the piston 8 are compressed. , flows into this wound, passes through the primary cups 9, 12, flows into the recesses 11, 15, flows through the supply port 3, flows into the reservoir 2, and drops the negative pressure in the reservoir 2. let This causes a negative pressure drop in the reservoir 2 and, in turn, in the recesses 11 and 1.
5 is displayed on the negative pressure detection member 36. Therefore, by displaying this negative pressure drop, it is detected that there is a flaw such as a blowhole on the inner surface of the cylinder 1.
After this, when the directional switching valve 26 is switched and the directional switching valves 31 and 39 are switched back to their original positions, the piston and piston rod inside the air-hydro cylinder 38 move to the right in the figure, and the sealing lid 21, piston 24, and packing 25 etc. will rise, so cylinder 1 can be replaced.

As explained above, according to this invention, a negative pressure source and a negative pressure detection member are connected to the recessed part of the piston to supply negative pressure into the recessed part, and the piston in the cylinder is slid to cause the negative pressure in the recessed part to be Since the structure detects the drop, if there is a damage such as a blow hole on the inner surface of the cylinder, the negative pressure inside the recess will change, and this can be easily detected by the negative pressure detection member, so it is possible to manually check the cylinder one by one. To easily, reliably, and automatically detect flaws such as blowholes inside a cylinder without inspecting the inside, improving work efficiency and significantly reducing the burden on inspection workers. It has the following effects:

[Brief explanation of the drawing]

The drawings are longitudinal sectional views showing an embodiment of the present invention. 1 ... cylinder, 1a, 1b ... first pressure chamber, 2 ... reservoir, 3 ... supply port, 4
. . . relief port, 5 . . . oil supply portion (fluid supply passage), 7, 8 . . . piston, 9, 12 . . . primary cup (first cup seal), 10, 1
3: secondary cup (second cup seal); 11, 15: recess; 14: pressure cup (third cup seal); 17: return spring; 21: sealing lid; 29: cylinder mechanism; 35: negative pressure source (vacuum pump); 36:
...negative pressure detection member, 38...air hydro cylinder.

Claims (1)

[Scope of utility model registration request] a cylinder with one end closed and the other end open;
a piston slidably provided in the cylinder; a recess provided on the outer periphery of the piston; a supply port provided in the cylinder so as to communicate with the recess; a first pressure on the cylinder closed end side of the recess when the piston enters the cylinder; a first cup seal that does not allow fluid to pass from the chamber to the recess and allows fluid in the recess to flow into the first pressure chamber through a small hole provided in the piston when the piston is returned by the spring; a second cup seal provided on the piston to be located on the cylinder open end side of the recess; and a second cup seal provided on the piston to be located on the cylinder open end side of the recess; a relief port provided in the cylinder so as to be located on the side and communicate with the first pressure chamber; and a relief port provided in the cylinder so as to communicate with the first pressure chamber when the piston enters the deepest into the cylinder. A master cylinder comprising a fluid supply passage provided in the cylinder, a means for closing the relief port, and a negative pressure supply means connected to the recess so as to freely supply and shut off negative pressure through the supply port. , a negative pressure detecting means communicating with the recess through the supply port, the negative pressure detecting means detects a drop in negative pressure in the recess by sliding the piston, and detects the inner surface of the cylinder. A master cylinder inspection device characterized by inspecting for scratches, etc.