JPH0244065Y2 - - Google Patents

Description

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

[Prior Art] 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 a drive chamber formed on the outside of each piston through a switching valve. These pistons are reciprocated by supplying air to the pistons to increase and output air pressure in a pressure intensifying chamber formed inside the pistons, and the switching valves are mechanically switched by the reciprocating movements of the pistons. A pressure increasing device according to the above is known from Japanese Utility Model Application Publication No. 116084/1984.

However, in such pressure boosters, when the secondary pressure reaches the set pressure or when the primary supply pressure decreases due to factory closures, etc., the switching valve is closed due to the piston moving at a low speed. When switching at low speed, there is a possibility that both supply ports will be blocked or supply will be supplied to both supply ports due to stopping during the switching, and consideration must be taken to prevent this from occurring. .

[Problems to be solved by the invention] The invention has an extremely simple structure, and allows the switching valve to be reliably switched by the fluid pressure acting on the valve body of the switching valve, and to maintain the switching position. This is the problem we are trying to solve.

[Means for Solving the Problems] In order to solve the above problems, the pressure increase device of the present invention includes a partition wall, a pressure increase cylinder and a drive cylinder sandwiching the partition wall, and a piston that reciprocates within these cylinders. , are connected by a rod that passes through the partition wall airtightly, and the pressure intensifying chambers on both sides of the piston in the pressure intensifying cylinder are communicated with the inlet port via an inlet check valve that only allows fluid to flow in, and also allows only fluid to flow out. In the pressure increase device, the pressurized air for driving is alternately supplied and discharged to the drive chambers on both sides of the piston in the drive cylinder by communicating with the outlet port through an outlet check valve that allows , A switching valve for supplying and discharging pressurized air to both drive chambers is provided on the partition wall, and the push rod of the valve body projects into the pressure increase chamber and the drive chamber on both sides of the partition wall, and an exhaust valve is provided on both sides of the valve body. A technical measure is adopted in which a back pressure chamber is formed and the area ratio of the drive chamber side cross-sectional area to the pressure intensification chamber side cross-sectional area of the push rod is slightly larger than the pressure increase ratio of the fluid.

[Operation] When the switching valve supplies pressure fluid to one drive chamber and exhausts the other drive chamber, the pistons of the drive cylinder and the pressure increase cylinder move together, thereby increasing the pressure. Pressurizes indoor air and sends it out from the output port. In this case, the switching valve is held in the switching position by the difference in the fluid pressure acting on the push rod in the pressure boosting chamber and the driving chamber.

When the piston reaches near the end of its stroke and presses the push rod, the valve element of the switching valve is switched to a position where supply and discharge of pressure fluid to and from the drive chamber are reversed.
In this case, due to the slight sliding of the valve body, the pressure fluid that had been flowing into one of the drive chambers passes through the back pressure chamber, and back pressure due to exhaust gas is generated against the valve body, which causes an effect. The switching valve is reliably switched and maintained in its switching position by the force and the acting force of the fluid in the drive chamber or intensifier chamber.

Switching the valve body and maintaining the switching position are as follows:
Since this is done based on the cross-sectional area difference of the push rods and the back pressure of the switching valve, the configuration is simplified.

[Embodiment] Fig. 1 shows an embodiment of the present invention. The partition walls 3 are airtightly connected via a gasket.

The inside of the pressure increase cylinder 1 is divided into pressure increase chambers 7a and 7b by a piston 6 that reciprocates within the cylinder chamber, and these pressure increase chambers 7a and 7b allow pressurized air to flow in and discharge it. It communicates with the inlet port 9 by means of inlet check valves 8a and 8b which prevent the pressurized air from flowing out, and with the outlet port 11 by means of outlet check valves 10a and 10b which allow the pressurized air to flow out and block its inflow. ing.

On the other hand, the drive cylinder 2 is moved into drive chambers 14a and 14b by a piston 13 that slides inside the cylinder chamber.
These drive chambers 14a, 14
b includes passages 15a, 15b and a partition wall 4 to be described later.
Pressure fluid is alternately supplied from the inlet port 9 by a switching valve 16 within the inlet port 9 .
The pistons 6 and 13 are integrated by a rod 17 that passes through the partition wall 4 in an airtight manner.

In the illustrated embodiment, since the piston 6 and the piston 13 are formed to have the same diameter, the pressure increase ratio n is 2, as will be understood from the following explanation. piston 6
It is also possible to make the pressure increase ratio n larger than 2 by making the diameter larger.

In order to provide a switching valve 16 for reciprocating the piston 13, the partition wall 4 is provided with a through hole, into which the sleeve 19 and the push rod guides 20a, 20b on both sides thereof are inserted. a valve input port 22 communicating with the inlet port 9;
and the passages 15a and 15b on both sides thereof, respectively.
Valve output ports 23a, 23b are provided which communicate with the drive chambers 14a, 14b via
Valve exhaust ports 25a and 25b are provided which communicate with the valves a and 24b.

The spool valve body 26 inserted into the sleeve 19 is
A land 27 that switches and communicates the valve output ports 23a, 23b with the valve input port 22 and the valve exhaust ports 25a, 25b.
Push rods 28a and 28b, which are formed at both ends, are connected to the push rod guide 20.
a and 20b are hermetically fitted and protrude into the drive chamber 14a and the pressure increase chamber 7b. And the drive chamber 14
The cross-sectional area of the push rod 28a protruding into the pressure increase chamber 7b is set to NA (N=n+α), which is slightly larger than the pressure increase ratio n, with respect to the cross-sectional area A of the push rod 28b protruding into the pressure increase chamber 7b.

Back pressure sleeves 29a, 29b are provided on the sleeve sides of the push rod guides 20a, 20b, and extend to a position close to the outer periphery of the spool valve body 26.
Back pressure chambers 30a and 30b are formed between 29b and lands 27a and 27b to temporarily store exhaust gas,
Although the configuration is such that the exhaust pressure acts as back pressure on the spool valve body 26 at the beginning of the outflow of exhaust gas from the valve output ports 23a and 23b, the back pressure sleeves 29a and 29b as described above are not provided. Even though
Although there are differences in degree, back pressure can be applied to the spool valve body 26.

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

FIG. 1 shows that the pistons 6 and 13 reach the end of their rightward stroke due to the pressurized air supplied to the drive chamber 14a, and the piston 6 switches the switching valve 16 to release the pressurized fluid from the inlet port 9. Valve output port 2
3b and the passage 15b to the drive chamber 14b, and the drive chamber 14a is supplied to the passage 15a and the valve output port 23a.
The state in which the valve is communicated with the exhaust port 24a through the valve exhaust port 25a is shown.

When the spool valve body 26 is in the switching position shown in FIG. , moves to the left in the figure, the pressure air in the pressure increase chamber 7a is increased, and the air in the drive chamber 14a is discharged to the atmosphere.

In this case, if the atmospheric pressure is P ₀ and the primary pressure at the inlet port 9 is P ₁ , then the push rod 28a
An acting force NAP ₀ is acting on the push rod 28b, and an acting force AP ₁ is acting on the push rod 28b. Typically,
The primary pressure P ₁ is sufficiently greater than NP ₀ , but by making it at least slightly greater than NP ₀ ,
Even if the piston starts moving, the spool valve body 26
is held in the switched state shown by fluid pressure.

The piston presses the push rod 28a near the end of its leftward stroke, and as shown in FIG. When the switching valve 16 is switched, primary pressure air flows into the drive chamber 14a through the valve output port 23a, and air in the drive chamber 14b begins to flow out from the valve output port 23b through the valve exhaust port 25b.

However, since the exhaust gas from the valve output port 23b temporarily flows into the back pressure chamber 30b, the back pressure chamber 30b
A relatively large back pressure acts on the spool valve body 26 at this time.

In this case, even if the back pressure does not act on the spool valve body 26, the push rods 28a, 28
Since b has a difference in cross-sectional area, the fluid pressure that moves the spool valve body 26 to the left ultimately acts, but the fluid pressure of the fluid flowing into the drive chamber 14a is P ₃ and the back pressure of the back pressure chamber is Pe, if the effective cross-sectional area of the back pressure chamber is A ₁ ,
The force pushing the spool valve body 26 to the left is NAP ₃ +
A ₁ Pe, the force pushing rightward is AP ₁ , so when the fluid pressure P ₃ flowing into the drive chamber 14a rises to at least P ₁ /N- A ₁ Pe/NA or more, the spool valve body 26 is pushed to the left. Since the force pushing the spool valve body 26 is larger than the force pushing it rightward, the spool valve body 26 moves to the left. Therefore, when the spool valve body 26 is slightly slid by the piston 13, the spool valve body 26 is moved even if no pressing force is applied by the piston.
is switched.

By switching the spool valve body, the drive chamber 14a
When pressurized air flows in from the inlet port 9 and air in the drive chamber 14b passes through the passage 15b and the switching valve 16 and is discharged from the exhaust port 24b, the moving direction of the pistons 6 and 13 is reversed to the right in the figure. However, the pressure of the air in the pressure increase chamber 7b is increased, and pressurized air is supplied from the inlet port 9 to the pressure increase chamber 7a.

When the piston moves to the right, when the pressure air in the pressure increase chamber 7b is increased, NAP ₁ acts on the push rod 28a and force AnP ₁ acts on the push rod 28b, but N is slightly smaller than the pressure increase ratio n. Because of its large size, the spool valve body is held in its switched position by the fluid pressure force acting on the push rod 28a.

The piston presses the push rod 28b near the end of the rightward stroke, and the spool valve body 2
6 slightly to the right, the valve input port 22
The valve output port 23b, the valve output port 23a, and the valve exhaust port 25a are switched to a position where they are slightly in communication.

In this case, if the fluid pressure in the drive chamber 14a is _P3 , a leftward force _NAP3 and a rightward force _nP1A + _A1Pe act on the spool valve body 26, so _P3 = _P1. Also, the acting force A ₁ Pe due to back pressure is AP ₁ (N-
n), the spool valve body 26 is switched by this force difference. In reality, the value of N-n is small,
In addition, since P ₃ decreases rapidly, the spool valve body immediately switches to the right and maintains this state.

Furthermore, even if the switching valve 16 is stopped in a neutral state with no primary pressure being supplied to the pressure booster, when primary pressure is supplied to the pressure boosting chambers 7a and 7b, fluid pressure is applied to the push rod 28b. As a result, the spool valve body 26 slides to the right in the figure, thereby releasing the neutral (blocked) state of the switching valve, supplying primary pressure to the drive chamber 14b, and starting.

[Effects of the invention] The pressure booster of the invention has an extremely simple configuration, and the switching valve that alternately supplies pressure fluid to the drive chamber can be controlled by the fluid pressure acting on the valve body of the switching valve. It can be held in the switching position.

In addition, when switching the switching valve, the fluid pressure acting on the back pressure chamber at the back of the valve element is used to switch the valve element, so even when the piston moves at low speed, the switching valve can be switched reliably. .

[Brief explanation of the drawing]

1 and 2 are vertical sectional views showing the operating state of an embodiment of the present invention. 1... Pressure increase cylinder, 2... Drive cylinder, 3
...Bulkhead, 6, 13... Piston, 7a, 7b...
... Pressure boosting chamber, 8a, 8b... Inlet check valve, 9...
...Inlet port, 10a, 10b...Outlet check valve, 11...Outlet port, 14a, 14b...Drive chamber, 16...Switching valve, 26...Spool valve body,
28a, 28b... Pushrod, 30a, 3
0b...Back pressure chamber.

Claims (1)

[Claims for Utility Model Registration] A piston in the pressure increase cylinder comprising a partition wall, a pressure increase cylinder and a drive cylinder sandwiching the partition wall, and a piston reciprocating within these cylinders is connected by a rod that penetrates the partition wall in an airtight manner. The pressure increasing chambers on both sides of the intensifying chamber are communicated with the inlet port via an inlet check valve that only allows fluid to flow in, and
It communicates with the outlet port through an outlet check valve that only allows fluid to flow out, and by switching the switching valve, pressurized air for driving is alternately supplied and discharged to the drive chambers on both sides of the piston in the drive cylinder. In the pressure booster, the partition wall is provided with a switching valve for supplying and discharging pressurized air to both drive chambers, and the push rod of the valve body is made to protrude into the pressure increase chamber and the drive chamber on both sides of the partition wall, and the push rod of the valve body is A pressure booster characterized in that exhaust back pressure chambers are formed on both sides, and the area ratio of the drive chamber side cross-sectional area to the pressure booster chamber side cross-sectional area of the push rod is slightly larger than the pressure increase ratio of the fluid.