JPS61252901A - Fluid circuit provided with booster device - Google Patents

Abstract

PURPOSE:To make pressure raisable only in case of being necessitated, by forming both low-pressure side and high-pressure side interconnecting ports in a peripheral part of a cylinder and, when a plunger exists an end of the high-pressure side, making the high pressure side interconnecting port so as to be closed. CONSTITUTION:A low-pressure side interconnecting port 4c and a high-pressure side interconnected port 4b both are formed in each position where both come into a state of being opened when a plunger 3 on a peripheral part of a cylinder 4 exists in an end of the low-pressure side but when this plunger 3 exists in an end of the high-pressure side, the high-pressure side alone comes into a state of being opened. And, the low-pressure side interconnecting port 4c is connected to each of check valves 9 and 12. With this constitution, when the low-pressure side interconnecting port 4c is closed, high pressure oil is discharged out of the high-pressure side port 4b, and when the low-pressure side interconnecting port 4c is opened, steady-state pressure is discharged, so that only in case of being necessitated, fluid pressure is raisable.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a fluid circuit equipped with a pressure increase device, and in particular to a fluid circuit that can increase the pressure of fluid in the fluid circuit to a required fluid pressure only when necessary. Regarding.

[Technical background of the invention and its problems]

Generally, in a machine tool such as an O-ring grinder, a hydraulically driven clamp device operated by a fluid circuit is used to engage a clamp member with a workpiece, press and hold the workpiece with the clamp member, and then Processing is performed on a workpiece. In this case, an oil motor is usually used as the actuator of the hydraulically driven clamping device, and a hydraulic screw clamp, hydraulic wedge clamp, or the like is used as the clamping member.

By the way, when the ramp member is engaged with the workpiece in this way, the clamp member may get caught in the workpiece due to the inertia of the oil motor, etc., and after the machining operation is completed,
When releasing the engagement between the clamp member and the workpiece, a large initial W! Low friction resistance occurs. Therefore, as a hydraulically driven clamping device and fluid circuit, 1.4
It is necessary to have an output of about 3.0 times as much and be able to overcome the above-mentioned initial frictional resistance.

Conventionally, oil motors or hydraulic pumps with enough output to overcome this initial frictional resistance have been used. During operation, it is necessary to operate a pressure reducing valve to reduce the pressure, making the equipment larger and more expensive.

(Object of the invention) The present invention has been made in consideration of these points,
It is an object of the present invention to provide a fluid circuit equipped with a pressure increase device that can increase the pressure of fluid in the fluid circuit to a required fluid pressure only when necessary, and can downsize the fluid circuit.

[Summary of the Invention] The present invention provides a fluid circuit equipped with a pressure booster, comprising: a plunger having two end faces having different fluid action areas; and the plunger is slidably disposed and communicates with a pressure fluid supply source. a cylinder having a low-pressure side port, an intermediate port, and a high-pressure side port, and a fluid supply pipe connecting the intermediate port and the fluid machine via a check valve; The intermediate port is arranged such that the side with a larger area faces the low pressure side port and the side with a smaller action area faces the high pressure side port, and when the plunger is at the sliding end on the low pressure side port side. The high pressure side port is cut off from the low pressure side port and is bored at a position communicating with the low pressure side port when the plunger is at the sliding end on the high pressure side port side, and the high pressure side port is connected to the check valve and the fluid machine. It is characterized by being connected to the fluid supply piping between the two.

According to the present invention, when pressure fluid is supplied to the low pressure side port while the low pressure side port and the intermediate port are blocked by the plunger, the end face of the plunger facing the low pressure side port is on the high pressure side. Since the fluid action area is larger than the end face facing the port, the fluid pressure discharged from the high pressure side port is greater than the pressure of the fluid supplied to the low pressure side port, and the increased pressure fluid operates the fluid machine. let Also, when the plunger moves and the low pressure side port and intermediate port communicate with each other, the pressure fluid supplied to the low pressure side port flows through the fluid supply piping through the intermediate port, and the fluid machine is operated with pressure fluid at a steady pressure. let

As described above, according to the present invention, it is possible to increase the pressure of the fluid in the fluid circuit to a required fluid pressure only when necessary, and in other cases, it is possible to flow fluid at a constant pressure.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

1 to 5 show a first embodiment of a fluid circuit according to the present invention, and reference numeral 1 represents an oil motor connected to a clamp mechanism (not shown). Also, code 2
1 shows a pressure increasing device that supplies pressurized fluid, such as pressurized oil, to the oil motor 1.

The main part of this pressure booster F2 is a rod-shaped plunger 3 which has a large diameter part 3a and a small diameter part 3b, and is formed so that the areas of action on oil at both ends thereof are different, and this plunger 3 is slidable. It is composed of a cylinder 4 that is held in place. Among these, the large diameter portion 3a of the plunger 3 is provided with a small diameter communication hole 5 that communicates between one end surface and the end surface on the small diameter portion 3b side. On the other hand, a low pressure side port 4a and a high pressure side port 4b are formed at both sliding ends of the plunger 3 of the cylinder 4, respectively. Also, cylinder 4
Inside is 1. A large-diameter sliding region 41 that allows the large-diameter portion of the plunger 3 to slide and a small-diameter guide region 42 that guides the small-diameter portion of the plunger 3 are formed. A low pressure supply port 4 that opens into the sliding area 41 is provided on the circumference of the cylinder 4.
C and a high pressure side communication port 4d are formed. This low pressure procurement common port 4C and high pressure side communication port 4
d indicates that when the plunger 3 is located at the low pressure side end (right end) in the sliding area 41 as shown in FIG.
, 4d are both in the open state, and when the plunger 3 is located at the high pressure side end (left end) as shown in FIG.
Only the low pressure procurement port 4C is in an open state, and the high pressure side communication port 4d is formed in a position where it is closed by the large diameter portion 3a of the plunger 3. Further, a drain port 4e is formed on the circumference of the cylinder 4. This drain port 4e is a sliding area 4 of the large diameter portion 3a of the plunger 3.
It is formed at the high pressure side end (left end) of 1.

Further, the low pressure side port 4a of the cylinder 4 is communicated with an oil supply/discharge section (not shown) via a pipe 6. On the other hand, the high pressure side port 4b of the cylinder 4 is communicated with the oil motor 1 via a pipe 7, and the oil motor 1 is further communicated with another oil supply/discharge section (not shown) via a pipe 8. In addition, a check valve 9 is installed in the low pressure supply common port 4C! One end of the low pressure side communication pipe 10 is connected to the pipe 6, while the other end of the low pressure side communication pipe 10 is connected to the pipe 6. Note that the check valve 9 installed in the low-pressure side communication pipe 10 prevents oil from flowing from the pipe 6 to the low-pressure procurement port 4C, and prevents oil from flowing from the low-pressure side communication port 4C to the pipe 6. It has the function of allowing the distribution of Moreover, one end of the high pressure procurement common pipe 11 is connected to the high pressure side communication port 4d, and the other end of this high pressure procurement common pipe 11 is connected to the pipe 7.
It is connected to the oil motor 1 as well as to the oil motor 1 . Furthermore, the upstream side of the check valve 9 of the low pressure side communication piping 10 and the high pressure side are connected! ! 11 are connected to each other through a communication pipe 13 in which a check valve 12 is interposed. Note that the check valve 12 installed in this communication pipe 13 is connected to the high-pressure procurement common pipe 1.
1 to the low-pressure side communication pipe 10, and from the low-pressure side communication pipe 10 to the high-pressure procurement communication pipe 11.
It has the function of allowing oil to flow to. In addition, a drain pipe 15 with a check valve 14 interposed in the drain port 4e.
One end of the drain pipe 15 is connected to the drain pipe 15, while the other end of the drain pipe 15 is connected to the distribution IF8. In addition, this drain pipe 15
A check valve 14 installed in the drain port 4e prevents oil from flowing from the pipe 8 to the drain port 4e.
Distributed from e! ! It has a function of allowing oil to flow to 8.

Next, the operation of the fluid circuit of this embodiment will be explained using FIGS. 1 to 5.

FIG. 1 shows the state of the fluid circuit immediately before the clamp and workpiece are released from each other. In this case, the plunger 3 is present at the low-pressure side end (right sliding end) of the cylinder 4, and the low-pressure procurement common port 4CJ5 and the high-pressure procurement common port 4d are in an open state. When the clamp and the workpiece are to be disengaged, oil is supplied from the oil supply/discharge section to the low pressure side port 4a through the piping 6.

In this case, the plunger 3 is gradually moved toward the high pressure side (left sliding end) by the oil.

As the plunger 3 moves, when the low pressure procurement common port 4C and the high pressure procurement common port 4d are closed by the large diameter portion 3a of the plunger 3 as shown in FIG. The pressure oil discharged from the port 4b is increased in pressure from the pressure oil supplied from the low-pressure side port 4a and presses the large diameter portion 3a, and this increased pressure oil is supplied to the oil motor 1. The oil motor 1 is then driven to start and rotate by this pressure oil, operating the connected clamp and releasing the engagement with the workpiece. Note that while the plunger 3 is moving toward the high pressure side, pressure oil is discharged from the drain port 4e to the pipe 8 via the drain pipe 15. Also, by the way, the oil pressure P of the high pressure side port 4b
2 represents the hydraulic pressure of the low pressure side port 4a as Pl and the diameter of the plunger 3 on the low pressure side.

Further, FIG. 3 shows the state of the fluid circuit when the clamp is retracted from the work after the engagement between the clamp and the work is released. In this case, the plunger 3 is present on the high-pressure side (left end) of the cylinder 4, and only the low-pressure procurement port 4c is open. Therefore, in this case, the pressure oil supplied to the low pressure side port 4a passes through the cylinder 4, a part of the low pressure side communication pipe 10, the evacuation pipe 13, and the high pressure side communication pipe 11 to the oil motor 1.
It will be supplied to The operating pressure of the oil motor 1 during this clamp retraction does not require a high pressure like that at the time of starting, and the oil motor 1 is operated at a steady pressure without requiring the operation of the pressure increase device 2.

On the other hand, FIGS. 4 and 5 show the process of returning the fluid circuit to the state shown in FIG. 1 again, and this can be used as the fluid circuit when engaging the clamp with the workpiece. In this case, high pressure as required when releasing the clamp is not required.

First, in order to operate in the opposite direction to that at the time of release, pressure oil is supplied to the oil motor 1 from the oil supply/discharge section through the pipe 8.

In this case, the oil motor 1 is rotated by the pressure oil in the opposite direction to that described above, and the pressure oil after passing through the oil motor 1 flows into the cylinder 3 from the high pressure side port 4b. This pressure oil causes the plunger 3 to gradually move toward the low pressure side. During this movement, oil in the low pressure side port 4a flows through the communication hole 5 to the large diameter portion 3 of the plunger 3.
It will flow into the sliding area of a. Then, the plunger 3 further moves to the low pressure side, and the low pressure side communication port 4C
When the high pressure side communication port 4d is opened (FIG. 5), the pressure oil after passing through the oil motor 1 is transferred to a part of the piping 7,
It flows to the pipe 6 through the high-pressure side communication pipe 11, the high-pressure side communication port 4d, the low-pressure side communication port 4C, and the low-pressure side communication pipe 10.

The fluid circuit of this embodiment having such a configuration and operation provides the following effects.

That is, it is possible to increase the pressure in the necessary circuit to the necessary force only when starting the oil motor 1, such as when disengaging the clamp from the workpiece, and then maintain the pressure at a steady state.

The main part of the pressure booster 2 includes a plunger 3 which has a large diameter part 3a and a small diameter part 3b, and has different areas of action on oil at both ends thereof, and a plunger 3 which is slidably connected to the plunger 3. Since the fluid circuit is composed of a holding cylinder 4, the construction of the fluid circuit is simple and compact, resulting in a reduction in cost compared to a conventional fluid circuit equipped with a special pressure increase device.

FIG. 6 shows a second embodiment of the fluid circuit according to the present invention, and the fluid circuit of this embodiment can also be used when engaging the clamp and the workpiece by combining two pressure increasing devices. The clamp device is configured to be able to supply pressurized fluid to the clamp device. The pressure increasing device in this case is indicated by the reference numeral 2' in FIG. Note that this pressure booster 2' has the same configuration as the pressure booster 2 described above, so the reference numerals of each component include a dash (') in the code of each corresponding component of the pressure booster @2.
It is shown with .

Further, FIG. 7 shows a third embodiment of the fluid circuit according to the present invention, and in the fluid circuit of this third embodiment,
The plunger 23 is formed into a cup shape with a recess formed in the center.

Further, the cylindrical member 21 into which the recess of the plunger 23 is fitted is inserted.
is formed in the cylinder 24 in the axial direction, and a drain port 4e is bored through this cylindrical member 21.

The fluid circuit of the third embodiment can also achieve the same functions and effects as the first embodiment, and furthermore, according to this fluid circuit, the longitudinal dimension of the plunger 23 can be shortened, so pressure can be increased. It becomes possible to downsize the device itself.

It should be noted that the present invention is not limited to the first to third embodiments, and for example, a variable throttle valve for fine adjustment may be provided in the ta 8.

Furthermore, in the description of this embodiment, the case of increasing the pressure of pressure oil has been described, but it can also be used as a pressure increasing device for fluids such as air and gas. Furthermore, the object to be operated is not limited to a clamp device, but can be favorably applied to equipment that requires a large operating pressure at the time of starting, finishing, etc.

(Effects of the Invention) As explained above, the pressure increase device according to the present invention can be easily installed in a general fluid circuit, increases the pressure of the fluid circuit only when necessary, and maintains a steady pressure in other cases. can be activated. This eliminates the need for large pumps, oil motors, etc. that were conventionally required to accommodate large outputs during startup, etc., and also eliminates the need to install a pressure reducing valve. In addition, the pressure booster is composed of a plunger formed to have different fluid action areas at both ends, and a cylinder that slides and holds the plunger.It has a simple structure and can be installed to There is no need to increase the size of the circuit.

As described above, according to the present invention, a compact and efficient fluid circuit can be obtained.

[Brief explanation of drawings]

1 to 5 are circuit diagrams showing a first embodiment of the fluid circuit according to the present invention. FIG. 1 is a diagram showing a state immediately before pressure increase, and FIG. 2 is a diagram showing a state immediately before pressure increase. Figure 3 shows the state in which the pressure has returned to steady state after pressure increase, and Figures 4 and 5 show the process of returning the fluid circuit from the state in Figure 3 to the state in Figure 1. FIG. 6 is a circuit diagram showing a second embodiment of the invention, and FIG. 7 is a circuit diagram showing a third embodiment of the invention. 1... Oil motor, 2.2'... Pressure booster, 3゜3'... Plunger, 4.4'... Cylinder, 4a
. 4a'...Low pressure side port, 4b, 4b'...High pressure side port. Applicant's representative Inomata Emotion 1st item 2nd item 3rd figure j$4

Claims (1)

[Claims] a plunger having two end faces with different fluid action areas; a cylinder in which the plunger is slidably disposed and has a low pressure side port communicating with a pressure fluid supply source, an intermediate port, and a high pressure side port; a fluid supply pipe connecting the intermediate port and the fluid machine via a check valve; the plunger has a side with a large action area facing the low pressure side port, and a side with a small action area facing the high pressure side port; The intermediate port is arranged toward the side port, and the intermediate port is arranged toward the side port.
When the plunger is at the sliding end on the low-pressure side port side, it is cut off from the low-pressure side port, and when the plunger is at the sliding end on the high-pressure side port side, it is bored at a position that communicates with the low-pressure side port, A fluid circuit equipped with a pressure booster, characterized in that a high pressure side port is connected to a fluid supply pipe between the check valve and the fluid machine.