JP2001242941A - Device for fluid pressure control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for fluid pressure control which controls fluid pressure so as to be able to easily confirm the work completion time, when it is used for a hydraulic caulking apparatus or the like. SOLUTION: The device comprises the first cylindrical fluid chamber 41 which is the smaller in diameter, the second fluid chamber 42 which is concentrically placed to the chamber 41 and is larger in diameter than the chamber 41, a valve body 51 which is tightly closing the end edge of the chamber 41 so as to open and close the opening between the chamber 41 and the chamber 42, a piston 52 which can slide tightly inside the chamber 42 and moves integrally with the valve body 51, a spring member 37 which is pressing on the piston 52 for the valve body 51 to close the end edge of the chamber 41, and a check valve which allows a free flow from the chamber 42 to the chamber 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the pressure of a fluid such as a hydraulic pressure, and is used, for example, for pressure control of a hydraulic caulking device.

[0002]

2. Description of the Related Art Conventionally, a mechanical caulking device has been used for caulking small parts and connecting them to other parts or frames.

A mechanical caulking device includes a table on which a work such as a small part is placed, a plunger arranged above the table and moving in a vertical direction, a pedal for an operator to step on with a foot, and a plunger by depressing a pedal. And a link mechanism configured to lower and increase the force.

[0004]

However, in the above-mentioned conventional mechanical caulking device, the mechanism is complicated, the operation sound is loud, and the timing when the caulking is completed cannot be easily confirmed. .

[0005] Therefore, it is conceivable to use a conventional caulking device of a hydraulic type. In such a case, the hydraulic caulking device includes a pedal, a cylinder for generating hydraulic pressure connected to the pedal, a piping material such as a hose, a hydraulic cylinder, and the like. An operator generates a hydraulic pressure by depressing a pedal, sends the generated hydraulic pressure to a hydraulic cylinder via a hose, and operates the plunger by the hydraulic cylinder.

[0006] This simplifies the mechanism and reduces the operation noise, but it is not possible for an operator to easily confirm the timing at which the swaging is completed with only the above-described configuration.

That is, when the operator depresses the pedal, hydraulic pressure is generated, and the plunger presses the work by the operation of the hydraulic cylinder. Whether the plunger presses the work with a predetermined force is determined by pressing the worker's pedal. I have to rely on the feeling of stepping on it. If the pressing force of the plunger is too small, the caulking will not be sufficiently performed, and if the pressing force of the plunger is too large, the caulked portion may be crushed, and any of these causes defective products.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. For example, when the present invention is used in a hydraulic caulking device or the like, the pressure control of the fluid is performed so that the timing at which caulking is completed can be easily confirmed. It is intended to provide an apparatus for performing the above.

[0009]

According to the first aspect of the present invention, there is provided a pressure regulating valve for discharging a fluid to an outflow point when the pressure of the fluid at the inflow point becomes higher than a set pressure,
An accumulator for accumulating the pressure of the fluid flowing out to the outflow point, and a check valve for free flow from the outflow point toward the inflow point are provided.

[0010] In the apparatus according to the second aspect of the present invention, the pressure regulating valve and / or the accumulator are provided with a small-diameter cylindrical first fluid chamber and the first fluid chamber concentrically with the first fluid chamber. A second fluid chamber having a diameter larger than the fluid chamber, and a valve body provided to close an end face of the first fluid chamber to open and close between the first fluid chamber and the second fluid chamber; A piston provided so as to be in sliding contact with an inner peripheral surface of the second fluid chamber and move integrally with the valve body; and a piston provided in a direction in which the valve body closes an end face of the first fluid chamber. A biasing spring member.

According to a third aspect of the present invention, there is provided a first fluid chamber having a small diameter and a cylindrical shape, and a second fluid chamber provided concentrically with the first fluid chamber and having a larger diameter than the first fluid chamber. A valve body provided to close an end face of the first fluid chamber for opening and closing between the first fluid chamber and the second fluid chamber, and a valve body provided with an inner peripheral surface of the second fluid chamber. A piston provided to slidably contact the valve body and move integrally with the valve body; a spring member for urging the piston in a direction in which the valve body closes an end surface of the first fluid chamber; and a second fluid chamber. And a check valve that flows freely from the first fluid chamber toward the first fluid chamber.

In the present invention, the valve body and the piston can be formed integrally. In other words, it can be considered that the part that functions as a valve is the valve body, and the part that functions to slide in the second fluid chamber is the piston.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a hydraulic circuit diagram of a caulking device 1 using a fluid pressure control device 13 according to the present invention, and FIG. 2 shows a relationship between a stroke of a cylinder 12 and a change in pressure of a pipeline HS. FIG.

In FIG. 1, a caulking device 1 includes a pedal 1
1, a cylinder 12, a pipeline HS, a pressure control device 13, a hydraulic cylinder 14, a plunger 15, a spring 16, a table 17, and the like.

The pressure control device 13 comprises a pressure regulating valve 21, an accumulator 22, and a check valve 23. The pressure regulating valve 21 causes the pressure oil to flow out to the accumulator 22 when the pressure of the pipeline HS becomes equal to or higher than the set pressure. The set pressure can be variably adjusted.

When the operator steps on the pedal 11,
The rod and piston of the cylinder 12 move, thereby generating hydraulic pressure and sending out pressure oil to the pipeline HS. The pressure oil sent via the line HS flows into the hydraulic cylinder 14 and moves its piston and piston rod downward.

The plunger 15 is pushed downward by the movement of the piston rod of the hydraulic cylinder 14, and the tip of the plunger 15 caulks the work WK set on the table 17.

In the pressure control device 13, an accumulator 22 accumulates pressure oil flowing out of the pressure regulating valve 21. Further, a predetermined preload is always applied to the stored pressure oil, and when the pressure in the pipeline HS is lower than that, the pressure oil in the accumulator 22 is transmitted through the check valve 23 by the preload. Returned to line HS.

Here, the set pressure P1 of the pressure control device 13
Is adjusted to a pressure at which the work WK can be exactly caulked by the hydraulic cylinder 14 and the caulking can be completed there.

As shown by the solid line in FIG. 2, as the worker steps on the pedal 11 and the stroke becomes deeper, the oil pressure gradually increases. During this time, the plunger 15
As a result, a pressure corresponding to an increase in the reaction force by the spring 16 is generated. When the plunger 15 hits the work WK, caulking is started, and the pressure rises sharply.

When the pressure rises and the pressure in the line HS reaches the set pressure P1, the actual caulking by the plunger 15 is completed, and the pressure oil in the line HS is supplied to the accumulator 22 via the pressure control device 13. Flow into As a result, the pressure in the pipeline HS drops rapidly, and the accumulator 2
2, the preload P2 decreases.

The preload P2 acts on the total area of the valve element pressure receiving area and the piston pressure receiving area, that is, the area of the second fluid chamber 42 in the pressure control device 13B described later.
The valve element 51 is kept open.

As a result, the pedal 11 suddenly becomes lighter, and it feels as if the pedal 11 is free, so that the operator can easily know that the caulking has been completed. Then, the operator loosens the pedal 11. Even if the pedal 11 is further depressed after the completion of the caulking, the pressure of the pipeline HS does not increase, so that the caulking is not excessively performed.

When the operator releases the pedal 11, the pressure oil in the accumulator 22 is returned to the pipeline HS via the check valve 23 by the preload P2. At the same time, the plunger 15 is raised by the spring 16, and the pressure oil in the hydraulic cylinder 14 is also returned to the pipeline HS. Since the preload P2 of the accumulator 22 is larger than the return hydraulic pressure (back pressure) from the hydraulic cylinder 14 by the spring 16, the accumulator 22
Most of the internal pressure oil returns to the pipeline HS, and the accumulator 22 also returns to the initial state.

It should be noted that the pressure oil in the pipeline HS is placed in an extra eye so that even if the piston of the cylinder 12 returns to the stroke end, the piston of the hydraulic cylinder 14 does not return to the stroke end. Thereby, the pipeline HS
, A certain low pressure (a pressure lower than the pre-pressure P2) is always generated, and a state without play or backlash can be achieved.

As described above, according to the pressure control device 13,
When the pressure reaches the set pressure P1, the pressure in the pipeline HS decreases rapidly, so that the operator can easily confirm the timing when the caulking is completed.

Therefore, the crimping becomes insufficient by stopping the pedal 11 before the pressure reaches the set pressure P1 as in the prior art. Further, even if the pedal 11 is depressed after the caulking is completed, since the pressure does not increase, there is no possibility that the caulked portion is excessively crimped or the caulked portion is crushed.

Thus, the pressure control device 13 is connected to the line H
It performs two functions of setting the maximum pressure of S and detecting that the pressure has been reached. Next, an example of the structure of the pressure control device 13 will be described.

FIG. 3 is a sectional view showing a specific example of the pressure control device 13B, and FIG. 4 is a right side view of the pressure control device 13B. 3 and 4, the pressure control device 13B includes:
A cover 32 is attached to the block 31 with bolts and is integrated. A screw shaft 33 is screwed into the cover 32.
3 moves in the axial direction with respect to the cover 32. Screw shaft 33
Spring holder 35 and adjustment body 36 rotatably abutting on the tip of
A spring 37 is mounted between the spring 37 and the spring receiver 53.

The block 31 has a cylindrical first fluid chamber 41 having a small diameter, a second fluid chamber 42 provided concentrically with the first fluid chamber 41 and having a larger diameter than the first fluid chamber 41, and a first fluid chamber 42. Room 4
1, a communication path 43 communicating with the first port, a port PT1, and a second port.
A check valve 44 is provided which is free-flowing from the fluid chamber 42 toward the first fluid chamber 41.

The adjusting body 36 includes a conical valve body 51 provided at the tip, a cylindrical piston 52, and a spring receiver 53.
Consists of The valve element 51 is provided so as to seal the end face of the first fluid chamber 41 by contacting the edge of the end face of the first fluid chamber 41, and the first fluid chamber 41 and the second fluid chamber 42 are moved by the movement thereof. Open and close between.

The piston 52 is provided with a packing 58, which moves in close contact with the inner peripheral surface of the second fluid chamber 42. The spring receiver 53 is urged by the spring 37 as described above, whereby the entire adjustment body 36 is urged leftward in the drawing. The pressure (set pressure P1) at which the valve element 51 opens is set according to the magnitude of the urging force, that is, according to the axial position of the screw shaft 33.

Therefore, by connecting the port PT1 to the pipeline HS, the pressure oil flows into the first fluid chamber 41 through the communication passage 43. The port PT1 or the communication passage 43 corresponds to an inflow point in the present invention.

When the pressure in the conduit HS reaches the set pressure P1, the valve element 51 opens, and the pressure oil flows into the second fluid chamber 42. The inlet of the second fluid chamber 42 corresponds to the outflow point in the present invention. As the valve element 51 and the piston 52 move, the volume of the pressure oil that can flow into the second fluid chamber 42 increases, and the pressure oil is accumulated therein.

In the second fluid chamber 42, the effective pressure receiving area of the valve element 51 is larger than in the first fluid chamber 41, so that the pressure of the pressure oil is reduced. Therefore, the pressure in the pipeline HS decreases to the preload P2. The ratio between the set pressure P1 and the preload P2 is equal to the ratio between the cross-sectional area of the first fluid chamber 41 and the cross-sectional area of the second fluid chamber 42. Therefore, for example, the second fluid chamber 42
Is set to be four times the cross-sectional area of the first fluid chamber 41, the preload P2 becomes one-fourth of the set pressure P1.

Pressure oil is accumulated in the second fluid chamber 42 according to the movement of the valve element 51 and the piston 52, and the second fluid chamber 42
Performs the function of an accumulator. When the pedal 11 is loosened, the pressure in the conduit HS becomes lower than the preload P2, so that the adjusting body 36 starts to return to the original position by being pushed by the spring 37, and the pressure oil in the second fluid chamber 42 Returns from the port PT1 to the pipeline HS via the first fluid chamber 41 or the check valve 23.

Thus, according to the pressure control device 13B, one device fulfills all the functions of the pressure control device 13 described above. In particular, when the pressure at the port PT1 exceeds the set pressure P1, it is necessary to release the pressure oil to the accumulator and return the released pressure oil from the accumulator again, so that the conventional relief valve cannot be used. However, the pressure control device 13 described above
B can be used for that purpose, and the set pressure P1 can be easily adjusted by turning the handle.

In the above-described embodiment, the communication path 43
Is closed with a steel ball, but instead of closing, a port may be provided and connected to the pipeline HS. In addition, the structure, shape, number, material, dimensions, circuit, and the like of each part of the pressure control devices 13B and 13 or the caulking device 1 can be various other than those described above.

[0039]

According to the present invention, when the pressure reaches the set pressure, the pressure sharply drops, so that, for example, when used in a hydraulic caulking device, the timing at which caulking is completed can be easily confirmed. .

According to the second or third aspect of the present invention, the pressure control device can be integrally formed with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a caulking device using a fluid pressure control device according to the present invention.

FIG. 2 is a diagram illustrating a relationship between a stroke of a cylinder and a change in pressure in a pipeline.

FIG. 3 is a sectional view showing an example of a specific pressure control device.

FIG. 4 is a right side view of the pressure control device.

[Explanation of symbols]

 13, 13B Pressure control device 21 Pressure regulating valve 22 Accumulator 23 Check valve 37 Spring member 41 First fluid chamber 42 Second fluid chamber 44 Check valve 51 Valve body 52 Piston

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H059 AA06 BB05 CC03 CD05 CE01 EE01 EE13 FF03 3H086 AA07 AB03 AD04 AD22 AF02 AF03 AF04 3H089 AA10 BB15 BB17 CC01 DA16 DB03 DB33 DC02 GG02 HH05 JJ03 5H316 AA18 EE03 BB03 JJ01 KK01 LL01

Claims (3)

[Claims] A pressure control valve for discharging the fluid to an outflow point when the pressure of the fluid at the inflow point is equal to or higher than a set pressure; an accumulator for accumulating the fluid flowing to the outflow point; And a check valve that allows free flow from a point to the inflow point. 2. The pressure regulating valve and / or the accumulator according to claim 1, wherein the first fluid chamber has a cylindrical shape having a small diameter, and a first fluid chamber provided concentrically with the first fluid chamber and having a larger diameter than the first fluid chamber. A two-fluid chamber, a valve element provided to close an end face of the first fluid chamber to open and close between the first fluid chamber and the second fluid chamber, and an inner periphery of the second fluid chamber A piston provided to slidably contact a surface and move integrally with the valve body; and a spring member for urging the piston in a direction in which the valve body closes an end surface of the first fluid chamber. The fluid pressure control device according to claim 1. 3. A first fluid chamber having a cylindrical shape having a small diameter, a second fluid chamber provided concentrically with the first fluid chamber and having a diameter larger than that of the first fluid chamber, and the first fluid chamber. A valve body provided so as to close an end face of the first fluid chamber to open and close the second fluid chamber; and a valve body which comes into close sliding contact with an inner peripheral surface of the second fluid chamber and is integrated with the valve body. A piston provided so as to move in a vertical direction; a spring member for urging the piston in a direction in which the valve element closes an end surface of the first fluid chamber; and a direction from the second fluid chamber to the first fluid chamber. And a check valve which is free-flowing.