JPH10267002A - Pressure booster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a change of output pressure due to that a pressure booster is formed into compactness and a set up attitude is changed, by forming a switch valve as a pilot type. SOLUTION: A switch valve 28 provided in a center body 22 of a pressure booster 21 is formed as a switch valve of pilot type having a main valve 46 supplying driving compressed air to and discharging it from drive chambers 38A, 38B by supplying pilot air to and discharging it from a pilot chamber 49 and pilot valves 47A, 47B operated by pressing of pistons 34a, 34b to supply pilot air to and discharge it from the pilot chamber, to separately set up the main valve 46 in a direction orthogonal to a moving direction of the piston and the pilot valve in a direction orthogonal to a moving direction of the piston.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to compressed air or nitrogen gas (hereinafter referred to as "pressure fluid") using compressed air.
The present invention relates to a pressure increasing device for increasing the pressure.

[0002]

2. Description of the Related Art Compressed air boosters for increasing the pressure of compressed air supplied to a pressure increasing chamber with driving compressed air supplied to a driving chamber are already known. FIG. 7 shows a schematic configuration of a known compressed air pressure intensifier. This pressure intensifier 1 sandwiches a center body 5 having an inlet port 2, an outlet port 3, and an exhaust port 4 for compressed air. , Cylinders 6a and 6b connected to both sides thereof, pistons 7a and 7b sliding in the cylinders in an airtight manner, and a rod 8 for integrally reciprocating the pistons.
The outer periphery of the rod 8 penetrating the center body 5 is hermetically sealed by rod packings 8a, 8a.

The cylinders 6a and 6b are provided with a piston 7
The pressure boost chambers 9A, 9B and the drive chambers 10A, 10B on the outside are hermetically partitioned by the pressure boost chambers 9A, 9B, and the pressure boost chambers 9A, 9B are provided in the center body 5. Check valve 11 that allows only fluid to flow into
a and 11b communicate with the inlet port 2 and
It communicates with the outlet port 3 through outlet check valves 12a and 12b that allow only fluid outflow from the pressure intensifying chamber.
On the other hand, the drive chambers 10A and 10B communicate with a direct-acting switching valve 13 for switching these drive chambers installed in the center body 5 to the inlet port 2 and the exhaust port 4 for communication.
Push rod 13 for switching this switching valve 13
a and 13b have their tips projecting into the pressure-increasing chambers 9A and 9B, respectively. Further, the pressure intensifier 1 has an outlet port 3
And a governor 16 for adjusting the secondary pressure (output pressure) of the pressurized fluid in the above. The governor 16 can adjust the secondary pressure of the pressurized air by adjusting the biasing force of the pressure adjusting spring.

[0004] The pressure intensifier 1 uses pistons 7a, 7a by compressed air supplied from a switching valve 13 to a driving chamber 10A.
When b moves to the left, the pressure of the compressed air in the pressure increasing chamber 9A is increased,
It is output from the outlet port 3 through the outlet check valve 12a. When the piston 7a presses the push rod 13a near the end of the left movement stroke, the switching valve 13 is switched and compressed air is supplied to the drive chamber 10B, so that the pistons 7a and 7b move rightward, thereby increasing the pressure in the pressure increasing chamber 9B. Is increased and output from the outlet port 3 through the outlet check valve 12b. When the piston 7b pushes the push rod 13b near the end of the rightward movement stroke, the switching valve 13 switches to the state shown in FIG.
A is supplied with compressed air.

However, in the above-mentioned known pressure intensifier, since the switching valve 13 for supplying and discharging the drive compressed air to and from the drive chambers 10A and 10B is a direct-acting type, the supply compressed air pressure is reduced due to the end of the work or the like. When the pistons 7a and 7b are driven at a low speed, when the switching valve 13 reaches near the neutral position, the pressing force of the pistons 7a and 7b does not act on the switching valve and the switching valve 13 stops at the neutral position. In some cases, the pressure intensifier cannot be restarted.
Further, since the direct-acting type switching valve 13 has a long axial length, the axial length of the center body 5 in which the switching valve 3 is installed becomes long, so that it is difficult to make the pressure booster 1 compact. It is. Further, the pressure increasing device 1 is connected to the pistons 7a, 7
b, the switching valve 13
Because of the influence of gravity, there is a problem that the output pressure of the pressure intensifying chamber fluctuates due to a change in the installation posture of the pressure intensifying device.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a pressure booster which can be reliably restarted even if the air pressure of compressed air drops and which can be downsized. Is to provide. A second object of the present invention is to provide a pressure booster in which the output pressure does not fluctuate due to a change in the installation posture.

[0007]

In order to solve the above-mentioned first problem, a pressure booster according to the present invention comprises a center body and a pair of cylinders sandwiching the center body, and a pair of cylinders reciprocating in these cylinders. The piston is connected so as to be integrally movable by a rod that penetrates the center body in an airtight manner, and a pair of drive chambers defined by one piston are connected to an air inlet port and an outlet port via a switching valve provided in the center body. And a pair of pressure-intensifying chambers defined by the other piston are connected to the above-mentioned inlet port or another fluid inlet port through an inlet check valve that allows only the inflow of fluid, and only the outflow of fluid is performed. And a pair of pistons with compressed air for driving supplied and discharged from the switching valve to a pair of driving chambers through an outlet check valve that permits the A pressure intensifier that reciprocates and increases and outputs compressed air or nitrogen gas supplied to a pressure intensifying chamber, wherein the switching valve is actuated by pilot air supplied to and exhausted from a pilot chamber. A main valve that switches and outputs compressed air to a pair of drive chambers, and a pilot valve that operates by pressing a piston to supply and discharge pilot air to and from the pilot chamber. The main valve and pilot valve are separated into a center body. It is characterized by being installed.

In order to solve the second problem, the main valve in the pressure booster is installed in a direction orthogonal to the moving direction of the piston, and the pilot valve is installed in a direction parallel to the moving direction of the piston. Features.

When the pilot air is supplied to the pilot chamber of the main valve, the compressed air is supplied to one of the driving chambers and the compressed air of the other driving chamber is discharged to the outside. And the pressure fluid is supplied to the other pressure intensifying chambers through the inlet check valve. Therefore, the pressure of one of the pressure intensifying chambers is increased by the sum of the fluid pressures of the pressure fluids supplied to these chambers. The fluid is pressurized and output from the fluid outlet port through an outlet check valve. When the piston presses the pilot valve near the end of the stroke in the predetermined direction, the main valve switches to supply compressed air to the other drive chamber and discharge compressed air from one drive chamber to the outside. This causes the pair of pistons to stroke in the direction opposite to the above direction, so that the pressure fluid in the other pressure-intensifying chamber is increased in pressure and output from the fluid outlet port through the outlet check valve.

In this pressure booster, a switching valve for supplying and discharging compressed air for driving to and from the driving chamber is a pilot switching valve.
Even if the piston is driven at a low speed due to a decrease in air pressure in the line or the like, when the piston presses the pilot valve, pilot air is supplied to and discharged from the pilot chamber, so that the main valve can be switched reliably. Therefore, since the main valve does not stop at the neutral position, the pressure booster can be restarted. In addition, since the main valve and pilot valve are separated from the center body and installed, the axial length of the entire switching valve can be shortened. Since the impact force due to the piston pressing does not directly act on the main valve, wear of the packings around the main valve due to the impact can be reduced.

Further, by providing the main valve in a direction perpendicular to the moving direction of the piston and the pilot valve in a direction parallel to the moving direction of the piston, compressed air for driving is supplied to the driving chamber by pressing the piston. Even if the pressure booster is installed in the vertical direction perpendicular to the direction of movement of the piston, the main valve is not affected by gravity. Fluctuations in pressure can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. In FIG. 1 showing a schematic configuration of the present invention, a flow path of compressed air for driving is indicated by a solid line, and a flow path of a pressure fluid for pressure increase (nitrogen gas in the illustrated example) is indicated by a dotted line. The pressure intensifier 21 shown in FIG. 1 includes a center body 22 and cylinders 23a and 23b mounted on both axial sides thereof. The center body 22 has a fluid inlet port 24 for supplying nitrogen gas for increasing pressure on the front surface, a fluid outlet port 25 for outputting nitrogen gas having increased pressure, and an inlet port for supplying compressed air for driving on the rear surface. A switching valve 28 having a main valve 46 and pilot valves 47A and 47B, which will be described later, and a governor 29 are provided. On the lower surface, a pressure intensifier 2
A center base 30 (see FIGS. 2 and 4) for attaching the unit 1 to an appropriate member (not shown) is attached by bolts.

The cylinders 23a and 23b are provided with cylinder tubes 31a and 31b, and side covers 32a and 32b for closing one end opening airtightly, and a plurality of (four in the illustrated example) penetrating the center body. Tie rod 3
3 (see FIG. 4), the pistons 34a, 34b reciprocating airtightly in the cylinders 23a, 23b are assembled to the center body 22 in an airtight manner.
Are connected so as to be movable integrally. The rod 35 is attached to the center body 22.
Packings 35a, 35 for hermetically sealing the outer periphery of
a, the intermediate chamber 3 opened to the outside by the flow path 36a
6 are formed.

In the cylinder 23a, a pair of drive chambers 38A and 38B are air-tightly partitioned by a piston 34a.
In the cylinder 23b, a pair of pressure-increasing chambers 41A and 41B are airtightly partitioned by a piston 34b. The drive chamber 38A on the center body 22 side (inside) is provided with the main valve 46.
The drive chamber 38B on the side (outside) of the side cover 32a communicates with the output port B of the main valve 46 via an air guide pipe 40a provided outside the cylinder tube 31a. On the other hand, the pressure increasing chamber 41A on the side of the center body 22 (inside) is connected to the center body 2 by a side plate 42a (see FIG. 2) attached to the center body.
2 is connected to the fluid inlet port 24 through an inlet check valve 43a incorporated in the outlet check valve 44a.
a, and communicates with the fluid outlet port 25 via a. Also,
The pressure increasing chamber 41B on the side (outside) of the side cover 32b is connected to the side cover 3b by a side plate 42b (see FIG. 2).
2b are connected to an inlet check valve 43b and an outlet check valve 44b, respectively.
b, 44b are connected to the fluid inlet port 2 by air guide pipes 40b, 40c provided outside the cylinder tube 31b.
4 and the fluid outlet port 25 respectively. The inlet check valves 43a and 43b are connected to the fluid inlet port 24.
To allow the inflow of nitrogen gas into the pressure intensifying chambers 41A and 41B to prevent the backflow of the nitrogen gas, and the outlet check valves 44a and 44b
Is for permitting outflow of nitrogen gas from the pressure intensifying chambers 41A and 41B and for preventing backflow thereof.

The switching valve 28 mounted on the center body 22 is configured as a pilot switching valve having a main valve 46 (see FIGS. 5A and 5B) and pilot valves 47A and 47B (see FIG. 6). , The main valve 46 is the piston 3
4a, 34b (in a direction perpendicular to the plane of FIG. 2), the pilot valves 47A, 47B
B is installed in a direction parallel to the movement direction of the piston. An air discharge member 27A having an air outlet port 27 at one end of the valve hole 48 of the main valve 46 is hermetically fitted with an air discharge member 27A, and a pilot chamber 49 having a smaller diameter than the valve hole 48 at the other end.
Are formed. The valve hole 48 has a supply port P for compressed air communicating with the air inlet port 26 and a drive chamber 3.
Output ports A and B communicating with 8A and 38B, respectively.
The back pressure sleeves 53a, 53a are provided on both sides in the axial direction of the sleeve 52 airtightly fitted in the valve hole 48.
b is fitted. A hollow cylindrical spool 54 slidably inserted into the sleeve 52 has locking step portions 55a and 55b on both sides in the axial direction of the inner peripheral surface, and has output ports A and B connected to the supply port P and the valve on the outer peripheral surface. The two lands which are switched to communicate with the inside of the hole 48 are both integrally formed.

The main valve 46 includes a pilot piston 57 that slides airtightly through the pilot chamber 49, and a locking step 55a.
A switching member 60 integrally connected by a valve rod to a first locking portion 58 that locks the first locking portion 58 and a second locking portion 59 that locks to the end of the spool 54 on the air outlet port side. And 5
A plurality of cutouts penetrating in the axial direction are formed on the outer periphery of 9. Further, the spring seat 6 fitted to the air discharging member 27A is provided.
A return spring 62 of the spool 54 is contracted between the first and second locking portions 59, and a plurality of notches in the axial direction are formed on the outer periphery of the flange of the spring seat 61. Therefore, the hollow portion of the spool 54 communicates with the air outlet port 27 by these cutouts.

The pilot valves 47A and 47B are provided on both sides in the axial direction of a through hole 64 penetrating the center body 22, and are fitted airtightly into the drive chamber 38A side and the pressure increasing chamber 41A side of the through hole 64. Sleeve 65a, 6
5b, valve seats 66a and 66b are formed to face each other. A radial passage is formed in the sleeve 65a to allow an annular groove 67 communicating with the air inlet port 26 to communicate with the inside of the sleeve, and an intermediate chamber (annular groove) 68 on the side of the pressure increasing chamber 41A and a valve are formed in the sleeve 65b. A radial passage is formed to individually communicate the annular pilot discharge groove 69 on the seat 66b side with the inside of the sleeve, and the intermediate chamber 68 and the pilot discharge groove 69 are formed.
Are individually opened to the outside by flow paths 68a and 69a.

The pilot valve bodies 71a, 71b which slide the sleeves 65a, 65b in an airtight manner are provided with valve seats 66a, 66b.
Push rods 73a having valve members 72a and 72b for opening and closing the valve and spring seats 75a and 75b inward in the axial direction. , 73b are slidably inserted, and push rod springs 74a, 74b are contracted between the bottom surface of the hollow portion and the base end of the push rod. A valve spring 76 having a smaller urging force than the push rod spring is contracted between the spring seats 75a and 75b having a plurality of notches in the axial direction on the outer periphery.
A chamber 77 between a and 66b communicates with the pilot chamber 49 through a pilot passage 49a. And the middle room 6
8 and the pilot discharge groove 69 are cut off from each other by a pilot valve body 71b.

The governor 2 attached to the center body 22 for adjusting the secondary pressure (output pressure) of nitrogen gas.
9, when the acting force of the secondary pressure of the nitrogen gas in the feedback chamber 83 is smaller than the set biasing force of the pressure regulating spring 87, the stem 79 a of the governor valve 79 closes the feedback passage 84 provided in the pressure regulating piston 80. , Governor valve 69
To lower the secondary pressure of the nitrogen gas in the feedback chamber 83 by supplying compressed air to the drive chambers 38A and 38B. If the pressure is large, the stem 79a opens the feedback passage 84 to open the feedback chamber 83.
The secondary pressure is adjusted by discharging the nitrogen gas to the primary side to lower the secondary pressure. This governor 29
Since the feedback path 84 communicates with the primary side of the nitrogen gas, wasteful consumption of the nitrogen gas discharged from the feedback path 84 can be eliminated. Further, a seal member 8 between the feedback chamber 83 and the governor valve 79 is provided.
Since the intermediate chamber 85 provided in 2 is opened to the outside by the flow path 85a, the compressed air and the nitrogen gas leaking to the intermediate chamber 85 can be discharged to the outside.

Adjustment of the set pressure by the governor 29 is performed by rotating a cap 90 rotatably mounted on a bonnet 89 in the same manner as in a known pressure intensifier.
By adjusting the biasing force of Reference numeral 94a in the figure denotes a pressure gauge that detects the primary pressure of the pressure fluid,
94b is a pressure gauge for detecting the secondary pressure.

Next, the operation of the above embodiment will be described with reference to FIG. In FIG. 1, pilot air is supplied to a pilot chamber 49 of a main valve 46, and a supply port P is connected to an output port A.
FIG. 5B shows a state in which the output port B communicates with the air outlet port 27 (see FIG. 5A), the compressed air is supplied to the drive chamber 38A, and the compressed air in the drive chamber 38B is discharged. As a result, the pistons 34a and 34b are moving rightward in the figure, so that the nitrogen gas in the pressure increasing chamber 41A is actuated by the compressed air pressure supplied to the driving chamber 38A and the nitrogen gas supplied to the pressure increasing chamber 41B. The pressure is increased by the sum of the acting force of the fluid pressure and output from the fluid outlet port 25 through the outlet check valve 44a. In this case, the ends of the push rods 73a and 73b are
4a, 74b and the urging force of the valve spring 76
8A and the pressure increasing chamber 41A, the pilot valve bodies 71a, 71b close the valve seats 66a, 66b.

When the piston 34b pushes the push rod 73b near the end of the rightward movement stroke, the pilot valve body 71b
Opens the valve seat 66b. Thereby, the pilot room 4
Nine pilot air flows through the pilot passage 49a and the valve seat 66.
Since the spool 54 moves rightward due to the urging force of the return spring 62 because the spool 54 is discharged to the outside through the b and the intermediate chamber 69, the supply port P and the output port B communicate with each other and the output port A is connected to the air outlet port 27. (See FIG. 5B). Therefore, the compressed air is supplied to the drive chamber 38B, the compressed air in the drive chamber 38A is discharged to the outside, and the pistons 34a and 34b move leftward, so that the nitrogen gas in the pressure increasing chamber 41B is increased in pressure and the outlet check valve 44b Through the fluid outlet port 25. In this case, since the pilot valve body 71a closes the valve seat 66a, the compressed air in the annular groove 67 communicating with the air inlet port 26 does not flow into the pilot chamber 49.

When the piston 34a pushes the push rod 37a near the end of the leftward stroke, the pilot valve body 71a is pushed by the urging force of the push rod spring 74a.
Opens the valve seat 66a. As a result, pilot air is supplied from the annular groove 67 to the pilot chamber 49 through the pilot passage 49a, and the switching member 60 moves to the left in the drawing, so that the spool 54 is locked to the locking step 55a. Is pressed by the first locking portion 58 and moves leftward (see FIG. 5A). Therefore, compressed air is supplied to the drive chamber 38A, and the pistons 34a and 34b move rightward in the drawing. In this case, the pilot valve body 71b is
6b is closed, so that the air in the pilot chamber 49 does not flow outside through the intermediate chamber 69.

In the above embodiment, the switching valve 28 is a pilot type switching, and the spool (valve element) 54 of the main valve 46 is switched by the pilot air supplied to and discharged from the pilot chamber 49. Even if the pistons 34a and 34b move at a low speed due to a decrease in the air pressure, the pistons 34a and 34b are not moved by the push rod springs 74a and 74b.
When the push rods 73a and 73b are pressed against the urging force of b, the pilot air is supplied to and exhausted from the pilot chamber 49, so that the main valve 46 can be switched reliably.
Also, when the pressing force of the pistons 34a, 34b is significantly reduced and the push rods 73a, 73b cannot be pressed against the urging force of the push rod springs 74a, 74b, the pilot air is supplied to the pilot chamber 49. Since it is not ejected, the switching position of the spool 54 does not change.
Therefore, since the main valve 46 does not stop at the neutral position, the pressure intensifier 21 can be reliably restarted. Also, push rods 73a, 73 by pistons 34a, 34b
Since the impact force of the 3b pressing does not directly act on the main valve 46, the main valve 46 and the pilot valves 47A and 47B are separately installed, so that the wear of the main valve 46 and packings and the like around the main valve 46 is reduced. be able to. Furthermore, since the axial length of the switching valve 28 is shorter than that of the direct acting switching valve, the axial length of the center body 22 is shorter, and the pressure intensifier 21 can be downsized.

The main valve 46 is connected to the pistons 34a and 34b.
The pressure intensifier 2
Even if 1 is installed in the vertical direction perpendicular to the direction of movement of the piston, the main valve 46 is not affected by gravity, so that fluctuations in output pressure due to a change in the installation position of the pressure intensifier can be eliminated. Further, the intermediate chamber 36 between the rod packings 35a, the intermediate chamber 68 of the pilot valve 47B, and the intermediate chamber 85 provided in the seal member 82 of the governor 29 are all opened to the outside by the flow paths. It is possible to prevent a decrease in purity of the nitrogen gas due to a mixture of the compressed air and the nitrogen gas leaking from each other at the location.

In the above embodiment, since the cylinders 23a and 23b have the same diameter, when the pressure of the compressed air supplied to the pressure intensifier 21 and the pressure of the nitrogen gas are the same, the pressure of the nitrogen gas is almost doubled. be able to. However, by making the diameter of the cylinder 23b on the pressure increasing side smaller than the diameter of the cylinder 23a on the driving side, the pressure of the nitrogen gas can be increased twice or more. In the above-described embodiment, as an example, the case where the pressure of nitrogen gas is increased and output is described. However, the pressure fluid to be increased in pressure in the pressure intensifier of the present invention is not limited to nitrogen gas. Can be increased, and in this case, the fluid inlet port 24 and the air inlet port 26 can be one common port, similarly to a known intensifier.

[0027]

According to the pressure booster of the present invention, the switching valve for supplying and discharging compressed air for driving to and from the driving chamber is a pilot switching valve having a main valve and a pilot valve, and the main valve is switched by pilot air. By doing so, the switching valve is reliably switched and does not stop at the neutral position, so that the pressure booster can be restarted. In addition, since the main valve and pilot valve are installed separately in the center body, the axial length of the switching valve is shortened. Therefore, the axial length of the center body is shortened and the pressure booster can be downsized. In addition, since the impact force due to the pressing of the piston does not directly act on the main valve, wear of the main valve and packings around the main valve is reduced, and the life can be extended.

The main valve is installed in a direction perpendicular to the direction of movement of the piston, and the pilot valve is installed in a direction parallel to the direction of movement of the piston. Even if the pressure booster is installed in a vertical position perpendicular to the direction of movement of the piston, the main valve is not affected by gravity. Fluctuations in output pressure can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment.

FIG. 2 is a vertical sectional view of a main part in the same manner.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a front view of the embodiment.

FIGS. 5A and 5B are diagrams showing an operation mode of a main valve of the switching valve.

FIG. 6 is a vertical sectional view of a pilot valve of the switching valve.

FIG. 7 is a schematic configuration diagram of a known pressure increasing device.

[Explanation of symbols]

 21 Pressure Booster 22 Center Body 23a, 24b Cylinder 24 Fluid Inlet Port 25 Fluid Outlet Port 26 Air Inlet Port 27 Air Outlet Port 28 Switching Valve 34a, 34b Piston 35 Rod 38A, 38B Drive Chamber 41A, 41B Booster Chamber 43a, 43b Inlet check valve 44a, 44b Outlet check valve 46 Main valve 47A, 47B Pilot valve 49 Pilot chamber

Claims (2)

[Claims] A center body and a pair of cylinders sandwiching the center body, and a pair of pistons reciprocating in the cylinders are connected so as to be integrally movable by a rod penetrating the center body in an airtight manner. And a pair of drive chambers defined by the piston are communicated with an air inlet port and an outlet port via a switching valve provided in the center body, and the pair of pressure boosting chambers defined by the other piston are connected to a fluid inflow chamber. Only the inlet port or another fluid inlet port through an inlet check valve that allows only fluid outflow is connected to a fluid outlet port through an outlet check valve that allows only outflow of fluid. A pair of pistons are reciprocated by the driving compressed air supplied to and discharged from the driving chamber of the pressure chamber, and the compressed air or nitrogen gas supplied to the pressure increasing chamber is increased in pressure and output. A pressure-intensifying device, wherein the switching valve is operated by pilot air supplied to and discharged from the pilot chamber to switch and output compressed air for driving to a pair of driving chambers; And a pilot valve for supplying and discharging pilot air to and from the pilot chamber, wherein the main valve and the pilot valve are separated from each other and installed in a center body. 2. The pressure booster according to claim 1, wherein the main valve is installed in a direction orthogonal to the direction of movement of the piston, and the pilot valve is installed in a direction parallel to the direction of movement of the piston.