JPH0326307Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a pressure increasing device that increases fluid pressure and outputs the increased pressure.

Conventionally, pistons in a pair of cylinders that are connected through a partition wall are connected by a rod that passes through the partition wall, and air pressure is alternately applied to the drive chamber formed on the outer surface of each piston through a switching valve. A pressure increase device that drives these pistons reciprocatingly by supplying the pistons to increase the pressure of air in a pressure increase chamber formed on the rod side of both pistons and outputs it is, for example, As already known from Publication No. 193101, in this pressure booster, the arrival of the piston at the stroke end is detected by a detector, and the detection signal is used to switch the switching valve. Therefore, there are problems such as the need for a detector and associated piping and wiring.

In order to solve this problem, it is possible to use the reciprocating motion of the piston to directly change the switching valve, and the inventor tried this experimentally. During operation, the switching of the switching valve is performed without any problem due to the reciprocating movement of the piston, but the consumption of secondary pressure decreases and it approaches the set pressure, or the supply pressure decreases. , when the piston is driven at a low speed, when the switching valve reaches near the neutral position, the piston's operating force no longer acts on the switching valve, causing the piston to stop at the intermediate position and not restart. I found out that there are also.

Problems to be Solved by the Invention The object of the present invention is to provide a pressure increase device that can reliably switch pistons even when the pistons operate at low speeds.

Means for Solving the Problems In order to achieve the above object, the pressure increasing device of the present invention connects the pistons in a pair of cylinders that are connected through a partition wall by a rod that penetrates the partition wall, and By alternately supplying air pressure to the drive chambers formed on the outer surface side via the switching valve, these pistons are driven back and forth, and the air pressure is increased in the pressure increase chambers formed on the rod side of both pistons, In a device configured to output it, a switching valve provided on the partition wall has a spool and a
A section comprising a pilot chamber at both ends of the spool and a push rod that is biased by a spring and projects from the pilot chamber to the pressure intensifying chamber, and the spool switches and communicates the valve output port with the valve input port and the valve exhaust port. a head that closes the through hole when the push rod is pressed by the piston; and a head that closes the through hole when the push rod is pressed by the piston, and a head that increases pressure when the spool moves to a substantially neutral position. It is characterized by being equipped with a guide hole that communicates between the chamber and the pilot chamber.

Operation In the pressure increase device configured as described above, when the piston presses one of the push rods, the push rod moves the spool to a substantially neutral position. At this time, the guide hole of the push rod opens into the pilot chamber, and the pressure boosting fluid from the pressure booster chamber flows into the pilot chamber through the push rod guide hole, and the fluid pressure of this pressure boost fluid adds to the pushing force of the piston. be sure to move the spool to the switching position. When the pressing force of the piston is removed and the push rod returns to its original state due to the biasing force of the spring, the above-mentioned guide hole closes, and at the same time, fluid from the valve input port enters the pilot chamber through the through hole, and the spool is filled with fluid. Maintain the switching state. Therefore, the piston is prevented from stopping near the neutral position.

Embodiment First, the outline of the pressure increasing device of the present invention will be explained with reference to FIG.

In the pressure booster schematically shown in FIG. 3, the pressure booster main body 1 includes an inlet port 2 and an outlet port 3, and the line air in the factory supplied to the inlet port 2 is pressurized and output from the outlet port 3. Ru.

The pressure booster main body 1 includes a pair of cylinders 5a and 5b that are connected to each other via a partition wall 4. Pistons 6a and 6b in each cylinder 5a and 5b are connected by a rod 7, and the rod 7 is connected to the partition wall 4. It is slidably penetrated in the axial direction in an airtight manner.
Each cylinder 5a, 5b has pressure increasing chambers 9a, 9 located on the partition wall 4 side divided by pistons 6a, 6b.
b and drive chambers 10a, 10b on the outer end surface side of the piston.
The inlet port 2 is communicated with the pressure intensifier chambers 9a, 9b via a pair of inlet check valves 11a, 11b disposed in the partition wall 4, and the line air is supplied from the inlet port 2 to the pressure intensifier chambers 9a, 9b. It allows the inflow into the intensifying chamber 9 and prevents its reverse flow.
a, 9b are communicated with the outlet port 3 via a pair of outlet check valves 12a, 12b disposed in the partition wall 4, allowing air compressed and pressurized in the pressure increase chambers 9a, 9b to flow out to the outlet port 3. At the same time, it prevents the backflow.

A switching valve 13 for reciprocating the piston is provided within the partition wall 4 of the pressure booster main body. In order to provide this switching valve 13, a through hole 20 is provided in the partition wall 4 as shown in FIG.
A valve input port 22 that communicates with via a regulating valve 15,
First and second valve output ports 23a, 23b communicating with the drive chambers 10a, 10b are provided on both sides thereof, and first and second valve exhaust ports 24a, 24b communicating with outside air are provided on both sides thereof. Each mouth of
Each of them communicates with a groove provided on the inner surface of the through hole 20. The sleeve 21 fitted into the through hole 20 has each groove airtightly partitioned by a seal member 33 provided on its outer periphery, and each groove is provided with an opening that communicates with each groove separately.

The spool 34 inserted into the sleeve 21 is
A land 35 for switching and communicating the valve input port 22 in the center
is provided with lands 36a and 36b at both ends thereof for opening and closing the valve exhaust ports 24a and 24b, and both end surfaces thereof are respectively recessed to form pilot chambers 37a and 37b between them and the push rod guide described later.
These pilot chambers 37a, 37b are connected to the spool 3.
A through hole 38a provided in the axial direction from the end surface of 4,
38b and a radial opening 39 from within the through hole.
a, 39b, the above land 35 and land 3
The compartments 40a and 40b between the 6a and 36b are communicated with each other, respectively. Push rod guides 41a and 41b that close both ends of the sleeve 21 are airtightly attached to the through hole 20 in the same manner as the sleeve 21, and push rod guides 45a and 45 are installed in the center thereof.
A hole 44 whose outer side is enlarged into which b is slidably inserted.
a, 44b are provided, and push rod guides 45a, 45b are hermetically inserted into these holes 44a, 44b by means of seal members 46a, 46b.

The inner ends of the push rods 45a, 45b are enlarged heads 47a, 47b that close the through holes 38a, 38b provided in the spool 34, but the enlarged heads 47a, 47b do not necessarily close the through holes 38.
It is not necessary to close a, 38b in an airtight manner. Also,
Retaining rings 49 are attached to the protruding portions of the push rods 45a and 45b that pass through the push rod guides 41a and 41b and protrude into the pressure increase chambers 9a and 9b.
Spring seats 50a, 50b by a, 49b
are locked, and the spring seats 50a, 50b
Springs 51a, 51b are provided between the inner surfaces of the push rod guides 41a, 41b and the outer surfaces of the push rod guides 41a, 41b to urge the push rods 45a, 45b outward.

Further, the push rods 45a, 45b have grooves 52a, 5 provided in the outer end surface thereof in the diametrical direction.
A guide hole 53a extends from 2b in the axial direction of the push rod.
53b is provided, and the guide holes 53a, 53b are provided in the openings 54 provided in the side surfaces of the push rods 45a, 45b.
a, 54b.

Next, the operation of the pressure increase device will be explained.

FIG. 1 shows the state of the switching valve 13 when pressure fluid is supplied to the drive chamber 10b and the fluid in the pressure increase chamber 9b is outputted with increased pressure. Spool 3
4 is in the state shown in FIG. 1, pressurized air from the valve input port 22 flows into the drive chamber 10b from the first valve output port 23a through the compartment chamber 40a. In this case, since the first valve exhaust port 24a is closed by the land 36a, the pressurized air flowing into the pilot chamber 37a from the compartment 40a through the opening 39a of the spool 34 and the through hole 38a is directed outward. The spool 34 is pressed without any leakage.
Further, the second valve output port 23b opens the drive chamber 10a to the atmosphere by communicating with the second valve exhaust port 24b via the compartment 40b. Then, the piston 6b moves to the right by the pressurized air flowing into the drive chamber 10b from the first valve output port 23a, increasing the pressure of the air in the second pressure intensifying chamber 9b, and this increased pressure passes through the outlet check valve 12b. and is sent out from outlet port 3.

By the rightward movement of the piston 6b, the piston 6b
When the push rod 45b is pressed against the biasing force of the spring 51b, the push rod 45b
moves to the right, and its enlarged head 47b presses the spool 34 while closing the through hole 38b of the spool 34, moving the spool to a substantially neutral position. When the spool 34 reaches near this neutral position, the opening 54b of the push rod 45b closes to the sealing member 46b.
It passes through and communicates with the pilot chamber 37b, so
The pressurized air in the pressure intensifying chamber 9b flows through the groove 52b and the guide hole 5.
3b, flows into the pilot chamber 37b through the opening 54b, and adds the increased air pressure to the pressing force of the piston 6b to reliably move the spool 34 to the right,
The flow path is switched so that air from the valve input port 22 flows to the second valve output port 23b.

By this rightward movement of the spool 34, the land 36
a opens the first valve exhaust port 24a, so the air in the drive chamber 10b flows through the first valve output port 23a and the compartment chamber 40.
a, the first valve exhaust port 24a is opened to the atmosphere, and the air in the pilot chamber 37a is also discharged from the spool 3.
Since the pilot chamber 37a is opened to the atmosphere through the through hole 38a and the opening 39a of the pilot chamber 37a, the air in the pilot chamber 37a does not interfere with the rightward movement of the spool 34.

Next, when the movement of the piston is reversed and the pressing force on the push rod 45b is removed, the push rod 45b returns to the state shown in FIG. 1 due to the biasing force of the spring 51b.
4b closes the communication between the pressure boosting chamber 9b and the pilot chamber 37b, while the pilot chamber 37b has an opening 3
9b, supply air flows in through the through hole 38b to maintain the rightward movement of the spool.

The supply air flowing into the compartment 40b from the valve input port 22 by the rightward movement of the spool is transferred to the second valve output port 2.
3b into the first drive chamber 10a and the piston 6
A is moved to the left, and the spool 34 is returned to the state shown in FIG. 1 by an operation similar to that described above, and this operation is repeated thereafter.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, locking pieces 60a and 60b that lock onto push rod guides 41a and 41b are fixed to push rods 45a and 45b, and springs 61 and 60b are fixed to push rods 45a and 45b.
a, 61b are provided in the pilot chambers 37a, 37b, and the spring seat of the previous embodiment is omitted. In this embodiment, the locking pieces 60a, 60b
prevents the push rods 45a, 45b from coming off, so the insides of the push rods 45a, 45b do not need to have enlarged heads as long as they have a diameter that can substantially close the through holes 38a, 38b.

According to the second embodiment, the left and right springs 61
The difference in the stretching force between a and 61b acts on the spool, but the whole can be made compact, and
By making the forces of the left and right springs 61a and 61b different, it is possible to shift the equilibrium position of the forces applied to the spool, effectively preventing the spool from stopping at the neutral position.
Rebooting can be facilitated.

According to the present invention, the switching valve is operated not only by the pressing force of the piston of the pressure booster, but also by causing the fluid whose pressure has been increased by the pressure booster to flow into the pilot chamber of the switching valve. By adding fluid pressure to the above-mentioned pressing force, the operating force of the spool becomes large and its operation becomes reliable.

Furthermore, when the spool is slid under this fluid pressure, the pilot chamber on the opposite side is opened to the outside air through the valve exhaust port, so the air in the pilot chamber does not interfere with the spool's sliding movement.

Furthermore, even if the pushing force of the piston no longer acts on the push rod of the switching valve due to the reversal of the piston, the supply fluid pressure will flow into the pilot chamber on the side where the fluid has flowed, and the spool will remain stable in its switching position. is maintained. Therefore, it is possible to prevent the piston from stopping near the neutral position and becoming unable to restart.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing a first embodiment of the switching valve of the present invention, Fig. 2 is a longitudinal cross-sectional view showing the second embodiment of the same, and Fig. 3 is a schematic diagram of the pressure booster of the present invention. 22... Valve input port, 23a, 23b... Valve output port, 24a, 24b... Valve exhaust port, 34... Spool, 37a, 37b... Pilot chamber, 38
a, 38b...through hole, 39a, 39b...opening,
45a, 45b... push rod, 51a, 5
1b, 61a, 61b... Spring, 54a,
54b...Opening.

Claims (1)

[Claims for Utility Model Registration] Pistons in a pair of cylinders that are connected through a partition wall are connected by a rod that passes through the partition wall, and air pressure is supplied to a drive chamber formed on the outer surface of each piston through a switching valve. In this device, the pistons are reciprocated by alternately supplying the pistons to increase the pressure of air in the pressure intensifying chambers formed on the rod sides of both pistons, and output it. The switching valve includes a spool, a pilot chamber at both ends of the spool, and a push rod that is biased by a spring and projects from the pilot chamber to the pressure booster chamber, and the spool connects the valve output port to the valve input port and the valve exhaust port. A head for closing the through hole when the push rod is pressed by a piston; A pressure intensifier characterized by comprising a conduit hole that communicates between a pressure intensifier chamber and a pilot chamber when the pressure intensifier moves to a pilot chamber.