JP2023002350A - Booster - Google Patents

Abstract

To provide a booster which can suppress a stop of a selector valve in a neutral position by accelerating a motion speed of a spool.SOLUTION: A booster comprises an opening/closing valve 25a which takes an open position P1 for making a first boosting chamber 22a and a first spool chamber 76a communicate with each other, and a closed position for blocking the communication of the first boosting chamber 22a and the first spool chamber 76a. The closed position is formed of a seal state with respect to a first pin 71 by a first rod packing 75a. The closed position P1 is formed by a release of a seal with respect to the first pin 71 by the first rod packing 75a. In a state that the opening/closing valve 25a is in the closed position, the opening/closing valve 25a takes the open position P1 by a time at which an air feed port 32 communicates with a second output port 34 which is different from a communicating first output port 33 due to a press of the first pin 71 by a first piston 15a.SELECTED DRAWING: Figure 3

Description

The present invention relates to a pressure booster.

As shown in FIGS. 15 and 16, the pressure booster 90 disclosed in Patent Document 1 includes a main body block 91 having an air supply port, an exhaust port, and an output port (not shown), and a pair of cylinders sandwiching the main body block 91. 92 and a pair of pistons 93 that reciprocate within the pair of cylinders 92 . A pair of pistons 93 are connected by a rod 94 passing through the body block 91 . Each cylinder 92 is partitioned by each piston 93 into a drive chamber 95 positioned outside in the axial direction of the cylinder 92 and a pressure boosting chamber 96 positioned inside. The body block 91 also incorporates an inlet check valve 97 a , an outlet check valve 97 b and a switching valve 98 . Both ends of the rod 94 are provided with air discharge slits 101 extending in the axial direction of the rod 94 .

The switching valve 98 is provided with a pair of pins 99 protruding into each pressure increasing chamber 96 . Further, the switching valve 98 is provided with a spool 100 sandwiched between a pair of pins 99 . When each pin 99 is pressed by each reciprocating piston 93 , the spool 100 is moved to switch the communication between the ports of the switching valve 98 . By switching communication between the ports, each drive chamber 95 is alternately communicated with the air supply port and the exhaust port. In addition, by connecting the pressure increasing chamber 96 and the driving chamber 95 through the atmosphere discharge slit 101 immediately before the piston 93 contacts the pin 99, the operating speed of the piston 93 is increased, and the spool 100 of the switching valve 98 is moved more. switching fast.

Japanese Utility Model Laid-Open No. 5-75501

However, in the pressure intensifying device 90 of Patent Document 1, the pressure in the pressure intensifying chamber 96 is lowered to the same pressure as the pressure in the drive chamber 95 in order to speed up the switching of the switching valve 98, but the pressure in the pressure intensifying chamber 96 It takes time until the pressure drops. As a result, it takes an extra time from when the pressure in the pressure increasing chamber 96 starts to decrease until the operating speed of the piston 93 increases. In particular, when the pressure in the pressure intensifying chamber 96 rises close to the set value set in the pressure intensifying device 90, the pressure in the piston 93 immediately before the pressure intensifying chamber 96 and the drive chamber 95 are communicated with each other via the air discharge slit 101 is particularly slow. Therefore, it becomes impossible to switch the switching valve 98 by moving the spool 100 at once. If the spool 100 cannot be moved all at once, there is a risk that the switching valve 98 will stop at the neutral position where both of the two drive chambers 95 are open.

A pressure intensifying device for solving the above problem comprises a main body block, a pair of cylinder chambers sandwiching the main body block, a shaft member extending through the main body block, and connected to both ends of the shaft member and arranged in each cylinder chamber. a pressure increasing chamber positioned on the main block side of the piston in each cylinder chamber; a drive chamber positioned on the opposite side of the pressure increasing chamber; and a pin pressed by each piston. and a switching valve for switching and connecting each of the drive chambers to an output port or an exhaust port via an air supply port, wherein the switching valve connects the air supply port, the exhaust port and the output port. a sleeve that reciprocates in the axial direction within the sleeve; a spool chamber that is defined outside both ends of the spool in the axial direction within the sleeve; a pair of pins having tip portions penetrating the sleeve in the axial direction; a return spring accommodated in a spring accommodation chamber arranged between the pair of pins in the axial direction; and tip portions of the pins. and a seal member for sealing between the sleeve and an open position for communicating the pressure intensifying chamber and the spool chamber; and an open position for disconnecting the pressure intensifying chamber from the spool chamber. An on-off valve is provided that assumes a closed position, the closed position being formed by sealing the pin with the sealing member, the open position being formed by releasing the sealing of the pin by the sealing member, and the In a state in which the on-off valve is in the closed position, the on-off valve is in the open position until the pin is pressed by the piston and the air supply port communicates with an output port different from the output port to which the on-off valve communicates. It is said that

According to this, the pressure of the air in the pressure increasing chamber is higher than that of the air in the spool chamber because the pressure is increased. Therefore, when the on-off valve is positioned at the open position, the air pressure-increased in the pressure-increasing chamber flows into the spool chamber at once, and the spool of the switching valve can be pressed at once. Compared to the case where the spool is moved by pressing the pin by the piston, the operating speed of the spool can be made higher, so that the switching valve can be prevented from stopping at the neutral position.

In the above pressure booster, the pin has a base portion arranged in the spool and a slit provided in the base portion and extending in the axial direction, and the slit is located at the position of the spool in the switching valve. , the spool chamber and the spring housing chamber may be communicated with each other.

According to this, after the spool is pressed by the air introduced from the pressure increasing chamber into the spool chamber, the spool chamber and the spring housing chamber communicate with each other through the slit. Then, the pressure in the spool chamber and the spring housing chamber become the same, and the thrust of the pin due to the pressure in the spool chamber can be suppressed, so that the compressed return spring can easily return. As a result, the pin can be easily returned to the position before being pressed by the return spring.

In the pressure intensifying device, the spool has a pressure receiving portion that receives air introduced from the pressure intensifying chamber into the spool chamber, and the sleeve has a valve seat on which the pressure receiving portion is seated to seal the spool chamber. and the pressure receiving portion and the valve seat are metal-sealed.

According to this, the spool can be moved faster than when it is not metal-sealed.
In the above pressure booster, the switching valve has a throttle channel that connects the spool chamber and the exhaust port, and when the on-off valve takes the closed position, the air in the spool chamber passes through the throttle channel. should be exhausted.

According to this, the switching valve has a function as a three-way valve with the on-off valve and the throttle channel.
In the pressure intensifying device described above, the throttle channel may be a fitting gap between the sleeve and the spool.

According to this, the switching valve can be made to function as a three-way valve without providing a restricted flow path in addition to the fitting gap between the sleeve and the spool. Therefore, the configuration of the switching valve can be simplified as compared with the case where the throttle channel is provided separately from the fitting gap between the sleeve and the spool.

In the above pressure booster, the switching valve has a valve seat that seals with the pressure boosting chamber, and is switched by the spool being moved by the thrust of the pin, and the fluid supplied from the pressure boosting chamber. and the switching operation by the thrust force of the pin, whichever is faster.

According to this, the switching valve is switched by the faster switching operation of the switching operation by the fluid and the switching operation by the thrust force of the pin. As a result, the reliability of the pressure booster is improved and the switching speed of the switching valve is improved.

According to the present invention, it is possible to prevent the switching valve from stopping at the neutral position by increasing the operating speed of the spool.

Sectional drawing which shows the pressure booster in embodiment. The circuit diagram which shows a pressure booster. FIG. 4 is a cross-sectional view showing a switching mechanism when increasing the pressure in the first pressure increasing chamber; FIG. 4 is a circuit diagram showing a switching mechanism when increasing the pressure in the first pressure increasing chamber; FIG. 5 is a cross-sectional view showing a switching mechanism when switching from the pressure increase in the first pressure increase chamber to the pressure increase in the second pressure increase chamber; FIG. 4 is a circuit diagram showing a switching mechanism for switching from pressure increase in the first pressure increase chamber to pressure increase in the second pressure increase chamber; FIG. 4 is a cross-sectional view showing a switching mechanism when increasing the pressure in the second pressure increasing chamber; FIG. 4 is a circuit diagram showing a switching mechanism when increasing the pressure in the second pressure increasing chamber; FIG. 4 is a cross-sectional view showing a switching mechanism when switching from the second pressure increase chamber to the pressure increase in the first pressure increase chamber; FIG. 4 is a circuit diagram showing a switching mechanism when switching from the second pressure increasing chamber to the pressure increasing of the first pressure increasing chamber; A table showing the relationship between the on-off valve and the booster chamber. FIG. 4 is a partial cross-sectional view showing an enlarged part of the valve seat of the on-off valve of the switching mechanism; FIG. 11 is a partial cross-sectional view showing an enlarged part of a valve seat of an on-off valve of a switching mechanism according to another embodiment; FIG. 11 is a partial cross-sectional view showing an enlarged part of a valve seat of an on-off valve of a switching mechanism according to another embodiment; Sectional drawing which shows the pressure booster of patent document 1. FIG. FIG. 2 is an enlarged cross-sectional view of a switching valve of the pressure booster of Patent Document 1;

An embodiment embodying a pressure booster will be described below with reference to FIGS. 1 to 12. FIG.
<Overall Configuration of Pressure Booster 10>
As shown in FIGS. 1 and 2 , the pressure booster 10 has a main body block 13 and a pair of cylindrical members 11 sandwiching the main body block 13 . One end of each cylindrical member 11 in the axial direction is connected to the main block 13, and the other axial end of each cylindrical member 11 is closed by closing members 12a and 12b.

The direction in which the axis of the tubular member 11 extends is defined as the axial direction X of the pressure increasing device 10 . The pressure booster 10 has a first cylinder chamber 14a as a cylinder chamber on one side in the axial direction X, and a second cylinder chamber 14b as a cylinder chamber on the other side in the axial direction X. As shown in FIG. Therefore, the pressure booster 10 has a pair of cylinder chambers 14a and 14b sandwiching the body block 13 therebetween. The first cylinder chamber 14a is partitioned by closing one cylinder member 11 with the body block 13 and one closing member 12a, and the second cylinder chamber 14b is partitioned by the body block 13 and the other closing member 12b. It is partitioned by closing member 11 . A first piston 15a as a piston is arranged in the first cylinder chamber 14a. A second piston 15b is arranged in the second cylinder chamber 14b.

The pressure booster 10 includes a shaft member 16 that passes through the main body block 13 in the axial direction X. As shown in FIG. A first piston 15a is connected to one end of the shaft member 16 in the axial direction X, and a second piston 15b is connected to the other end of the shaft member 16 in the axial direction X. As shown in FIG. The first piston 15 a and the second piston 15 b are fastened to the shaft member 16 by fastening members 17 .

The first piston 15a divides the first cylinder chamber 14a into a first pressure-increasing chamber 22a as a pressure-increasing chamber and a first drive chamber 21a as a drive chamber. The first pressure increasing chamber 22a is positioned on the main body block 13 side in the axial direction X. As shown in FIG. The first drive chamber 21a is located on the side opposite to the first pressure increasing chamber 22a. The first drive chamber 21a is positioned closer to the closing member 12a than the first pressure increasing chamber 22a. Air as a fluid is supplied to and discharged from the first drive chamber 21a, so that the first pressure increasing chamber 22a increases the pressure of the air.

The second piston 15b divides the second cylinder chamber 14b into a second pressure-increasing chamber 22b as a pressure-increasing chamber and a second drive chamber 21b as a drive chamber. The second drive chamber 21b is located on the opposite side in the axial direction X from the second pressure increasing chamber 22b. The second drive chamber 21b is located closer to the closing member 12b than the second pressure increasing chamber 22b. As air is supplied to and discharged from the second drive chamber 21b, the second pressure increasing chamber 22b increases the pressure of the air.

The first pressure-increasing chamber 22a and the second pressure-increasing chamber 22b are each connected to the air supply source 1 via an inlet check valve 18a. The inlet check valve 18a only allows air to flow from the air supply source 1 into the first pressure-increasing chamber 22a and the second pressure-increasing chamber 22b. Also, the first pressure-increasing chamber 22a and the second pressure-increasing chamber 22b are each connected to the discharge port 2 via an outlet check valve 18b. The outlet check valve 18b only allows air to flow out to the discharge port 2 from the first pressure increasing chamber 22a and the second pressure increasing chamber 22b.

The pressure booster 10 has a regulating valve 19 . The regulating valve 19 has a pressure setting (not shown) by spring setting. As shown in FIG. 2 , the output pressure of the discharge port 2 is fed back to the regulating valve 19 . The regulating valve 19 supplies the air supplied from the air supply source 1 to a switching valve 24 of the switching mechanism 20, which will be described later, by adjusting the air supplied from the air supply source 1 according to the discharge pressure.

The first drive chamber 21 a and the second drive chamber 21 b are connected to the air supply source 1 via the switching valve 24 and the adjusting valve 19 of the switching mechanism 20 . The switching mechanism 20 includes a 5-port 2-position switching valve 24 and a pair of opening/closing switches for opening and closing a flow path between the pressure chambers at both ends of the switching valve 24 and the first pressure increasing chamber 22a or the second pressure increasing chamber 22b. valves 25a and 25b. The switching valve 24 is a fluid pressure operated valve that is operated by the fluid pressure of air. Each of the on-off valves 25a and 25b is a mechanically operated valve operated by operating a first pin 71 and a second pin 72, which will be described later, by a first piston 15a and a second piston 15b. The switching mechanism 20 is configured as a pilot type switching valve that pilot-operates a switching valve 24 by opening/closing valves 25a and 25b. At this time, the first pin 71 and the second pin 72 mechanically operate the on-off valves 25a and 25b, and also function as valve elements of the on-off valves 25a and 25b.

In addition, the first piston 15a and the second piston 15b are arranged radially inside each cylindrical member 11 . Piston packings 23 are attached to the outer peripheral surface 150a of the first piston 15a and the outer peripheral surface 150b of the second piston 15b, respectively.

<Structure of Switching Mechanism 20>
Next, the switching mechanism 20 will be described in detail.
As shown in FIG. 3 , the switching mechanism 20 has a switching valve 24 . The switching valve 24 has a sleeve 31 and a spool 38 reciprocally arranged within the sleeve 31 . In this embodiment, the spool 38 is a metal spool. The switching mechanism 20 has a first pin 71 and a second pin 72 as pins and a return spring 79 . The first pin 71 is arranged on one end side of the spool 38 in the axial direction, and the second pin 72 is arranged on the other end side of the spool 38 in the axial direction. Each of the first pin 71 and the second pin 72 is arranged on the inner peripheral side of the spool 38 in a sealable state. Also, each of the first pin 71 and the second pin 72 is arranged in a slidable state on the inner peripheral side of the spool 38 . The first pin 71 and the second pin 72 are push pins. A return spring 79 is arranged between the first pin 71 and the second pin 72 .

The switching valve 24 can be directly operated by engaging the first pin 71 with the spool 38 in the axial direction X when the first pin 71 is pressed by the first piston 15a. That is, the pressure booster 10 can move the spool 38 by the thrust of the first pin 71 . Similarly, the switching valve 24 can be directly operated by engaging the second pin 72 with the spool 38 in the axial direction X when the second pin 72 is pressed by the second piston 15b. That is, the pressure booster 10 can move the spool 38 by the thrust of the second pin 72 . In this case, the first pin 71 and the second pin 72 function as mechanically operated valves for mechanically operating the switching valve 24 . Therefore, the switching mechanism 20 constitutes a fluid pressure operation valve and a mechanical operation valve.

For example, if the air pressure is high enough, the air pressure will cause the spool 38 to move. On the other hand, when the spool 38 cannot move stably due to the air pressure, such as when the air pressure is low, the thrust of the first pin 71 and the second pin 72 moves the spool 38 . In this way, the pressure booster 10 moves the spool 38 by performing fluid pressure operation with air or mechanical operation with the first pin 71 and the second pin 72 according to the pressure of the air. Between the fluid pressure operation by air and the mechanical operation by the first pin 71 and the second pin 72, priority is given to the one having a higher operating speed. The direction in which the axis L of the sleeve 31 extends is the direction of the axis of the switching valve 24 . Since the axial direction of the switching valve 24 coincides with the axial direction X of the pressure booster 10, the axial direction of the switching valve 24 is described as "axial direction X".

The sleeve 31 is formed with an air supply port 32 , a first output port 33 , a second output port 34 , a first exhaust port 35 and a second exhaust port 36 . The air supply port 32 , the first output port 33 , the second output port 34 , the first exhaust port 35 , and the second exhaust port 36 extend from one end side to the other end side in the axial direction X of the sleeve 31 . , the first output port 33, the air supply port 32, the second output port 34, and the second exhaust port 36 are arranged in this order.

A receiving hole 37 extending in the axial direction X is formed inside the sleeve 31 . The accommodation hole 37 communicates with the air supply port 32, the first output port 33, the second output port 34, the first exhaust port 35, and the second exhaust port 36, respectively.

A first valve seat 41 is formed on the inner peripheral surface of the sleeve 31 on the first pressure increasing chamber 22a side along the axial direction X. As shown in FIG. A second valve seat 42 is formed between the first exhaust port 35 and the first output port 33 along the axial direction X on the inner peripheral surface of the sleeve 31 . A third valve seat 43 is formed between the first output port 33 and the air supply port 32 along the axial direction X on the inner peripheral surface of the sleeve. Further, a fourth valve seat 44 is formed between the air supply port 32 and the second output port 34 along the axial direction X on the inner peripheral surface of the sleeve 31 . A fifth valve seat 45 is formed between the second output port 34 and the second exhaust port 36 along the axial direction X on the inner peripheral surface of the sleeve 31 . A sixth valve seat 46 is formed on the inner peripheral surface of the sleeve 31 on the second pressure increasing chamber 22b side along the axial direction X. As shown in FIG.

A spool 38 for switching air flow paths is accommodated in the accommodation hole 37 so as to be able to reciprocate in the axial direction X. As shown in FIG.
A first valve portion 51 , a second valve portion 52 , a first pressure receiving portion 61 , and a second pressure receiving portion 62 are formed in the spool 38 so as to be separated from each other in the axial direction X. As shown in FIG. The first valve portion 51, the second valve portion 52, the first pressure receiving portion 61, and the second pressure receiving portion 62 are arranged in the axial direction X from one end to the other end such that the first pressure receiving portion 61, the first valve portion 51, The second valve portion 52 and the second pressure receiving portion 62 are arranged in order. The outer diameter of the spool 38 at the first pressure receiving portion 61 , the first valve portion 51 , the second valve portion 52 and the second pressure receiving portion 62 is slightly smaller than the inner diameter of the sleeve 31 .

The first pressure receiving portion 61 is formed on one end side of the spool 38 in the axial direction X. As shown in FIG. The first pressure receiving portion 61 is flange-shaped. The outer peripheral surface 61 a of the first pressure receiving portion 61 overlaps the inner peripheral surface 410 of the first valve seat 41 in the axial direction X. As shown in FIG.

Between the first pressure receiving portion 61 and the first valve seat 41, a first throttle passage 80a is formed as a fitting gap. The first throttle channel 80 a functions as a communication channel that connects the first spool chamber 76 a and the first exhaust port 35 . When air is supplied to the first spool chamber 76a, the operating pressure of the air to the spool 38 is maintained even though the air leaks slightly from the first throttle passage 80a. When the air is no longer supplied to the first spool chamber 76a, the air is discharged from the first throttle channel 80a to the first exhaust port 35, so that the pressure in the first spool chamber 76a becomes atmospheric pressure. In this manner, the first throttle channel 80a is formed so as to suppress air leakage during movement of the spool 38 within an allowable range. The first throttle channel 80a is a metal seal.

The second pressure receiving portion 62 is formed on the other end side in the axial direction X of the spool 38 . The second pressure receiving portion 62 is flange-shaped. The outer peripheral surface 62 a of the second pressure receiving portion 62 overlaps the inner peripheral surface 460 of the sixth valve seat 46 in the axial direction X. As shown in FIG.

Between the second pressure receiving portion 62 and the sixth valve seat 46, a second throttle passage 80b, which is a fitting clearance, is formed. The second throttle passage 80b functions as a communication passage that connects the second spool chamber 76b and the second exhaust port 36. As shown in FIG. When air is supplied to the second spool chamber 76b, the operating pressure of the air to the spool 38 is maintained even though the air leaks slightly from the second throttle passage 80b. When air is no longer supplied to the second spool chamber 76b, the air is discharged from the second throttle channel 80b to the second exhaust port 36, so that the pressure in the second spool chamber 76b becomes atmospheric pressure. In this manner, the second throttle channel 80b is formed so as to suppress air leakage during movement of the spool 38 within an allowable range. The second throttle channel 80b is a metal seal.

In order to function in this way, the first throttle channel 80a and the second throttle channel 80b are set so that the length in the axial direction X differs between the location where sealing is required and the location where sealing is not required. ing. Therefore, the discharge flow rates of air from the first throttle channel 80a and the second throttle channel 80b are different.

Therefore, in the pressure booster 10, air is supplied to the first pressure receiving portion 61 and the second pressure receiving portion 62 from the on-off valves 25a and 25b, and air is supplied by the first throttle passage 80a and the second throttle passage 80b. Discharge allows for hydraulic operation.

As shown in FIG. 2 , the first drive chamber 21 a is configured to alternately communicate with the air supply source 1 and the exhaust port 5 via the first flow path 3 , switching valve 24 and regulating valve 19 . Similarly, the second drive chamber 21 b is configured to alternately communicate with the air supply source 1 and the exhaust port 5 via the second flow path 4 , the switching valve 24 and the regulating valve 19 .

The switching valve 24 can take two positions, a first position P1 and a second position P2.
3 and 4 show a state in which the switching valve 24 is in the first position P1 and the pressure in the first pressure increasing chamber 22a is increased. At this time, both the on-off valves 25a and 25b are closed.

7 and 8 show a state in which the pressure in the second pressure increasing chamber 22b is increased when the switching valve 24 is at the second position P2. At this time, both the on-off valves 25a and 25b are closed.
5 and 6 show a state in which the pressure increasing chamber to be increased is switched from the first pressure increasing chamber 22a to the second pressure increasing chamber 22b. The on-off valve 25a is at the open position P4, the on-off valve 25b is at the closed position P5, and the switching valve 24 is switched to the second position P2.

9 and 10 show a state in which the pressure increasing chamber to be increased is switched from the second pressure increasing chamber 22b to the first pressure increasing chamber 22a. The on-off valve 25a is at the closed position P3, the on-off valve 25b is at the open position P6, and the switching valve 24 is switched to the first position P1.

FIG. 11 shows the relationship between the on-off valves 25a and 25b, the first pressure-increasing chamber 22a, and the second pressure-increasing chamber 22b. The states shown in these figures will be described below.
As shown in FIG. 3 or 4 , at the first position P1, the first valve portion 51 is seated on the second valve seat 42 and the second valve portion 52 is seated on the fourth valve seat 44 . At the first position P<b>1 , the first pressure receiving portion 61 is seated on the first valve seat 41 and part of the second pressure receiving portion 62 is seated on the sixth valve seat 46 .

Note that when the movement of the spool 38 is stopped at the first position P1 as shown in FIG. They are separated by X. That is, the length of the fitting gap between the second pressure receiving portion 62 and the sixth valve seat 46 is short by the distance in the axial direction X from the inner peripheral surface 460 of the sixth valve seat 46 . Therefore, compared to the case where the entire outer peripheral surface 62a of the second pressure receiving portion 62 is in contact with the inner peripheral surface 460 of the sixth valve seat 46 while the spool 38 is moving, the The contact area between the outer peripheral surface 62a of the second pressure receiving portion 62 and the inner peripheral surface 460 of the sixth valve seat 46 is small. As a result, the second throttle channel 80b can easily discharge air from the second spool chamber 76b to the second exhaust port 36. As shown in FIG.

The second spool chamber 76b communicates with the second exhaust port 36 through a second throttle channel 80b. A second pin 72 functioning as a valve element of the on-off valve 25b is closed by a second rod packing 75b functioning as a valve seat. Therefore, the pressure in the second spool chamber 76b becomes the atmospheric pressure by discharging the air to the second exhaust port 36 through the second throttle channel 80b.

At this time, the second slit 74b is not closed by the spool 38, so the spring housing chamber 78 and the second spool chamber 76b are in communication. Spring chamber 78 is therefore at atmospheric pressure as well. On the other hand, since the first slit 74a is closed by the spool 38, the spring housing chamber 78 and the first spool chamber 76a are isolated.

At the first position P1, the air supply port 32 and the first output port 33 communicate, and the second output port 34 and the second exhaust port 36 communicate. Also, the air supply port 32 and the first output port 33 are blocked from the first exhaust port 35, and the second output port 34 and the second exhaust port 36 communicate with the second spool chamber 76b.

Therefore, when the switching valve 24 takes the first position P1, the air supplied from the air supply source 1 through the regulating valve 19 flows from the first output port 33 through the first passage 3 into the first drive chamber 21a. supplied. At the same time, the air in the second drive chamber 21b is discharged from the second exhaust port 36 through the second flow path 4. As shown in FIG. In the state shown in FIG. 3, the air in the second spool chamber 76b is discharged from the second exhaust port 36 through the second throttle passage 80b.

As shown in FIG. 7 or 8, at the second position P2, the first valve portion 51 is seated on the third valve seat 43 and the second valve portion 52 is seated on the fifth valve seat 45. As shown in FIG. At the second position P<b>2 , the first pressure receiving portion 61 is separated from the first valve seat 41 and the second pressure receiving portion 62 is seated on the sixth valve seat 46 .

7 or 8 where the movement of the spool 38 is stopped at the second position P2, a part of the outer peripheral surface 61a of the first pressure receiving portion 61 is is spaced apart in the axial direction X from . That is, the length of the fitting gap between the first pressure receiving portion 61 and the first valve seat 41 is short by the distance in the axial direction X from the inner peripheral surface 410 of the first valve seat 41 . Therefore, compared to the case where the entire outer peripheral surface 61a of the first pressure receiving portion 61 is in contact with the inner peripheral surface 410 of the first valve seat 41 while the spool 38 is moving, the The contact area between the outer peripheral surface 61a of the first pressure receiving portion 61 and the inner peripheral surface 410 of the first valve seat 41 is small. As a result, the first throttle channel 80 a facilitates discharging air from the first spool chamber 76 a to the first exhaust port 35 .

The first spool chamber 76a communicates with the first exhaust port 35 through a first throttle channel 80a. A first pin 71 functioning as a valve body of the on-off valve 25a is closed by a first rod packing 75a functioning as a valve seat. Therefore, the pressure in the first spool chamber 76a becomes the atmospheric pressure by discharging the air to the first exhaust port 35 through the first throttle channel 80a.

At this time, since the first slit 74a is not closed by the spool 38, the spring housing chamber 78 and the first spool chamber 76a are in communication. Therefore, the spring housing chamber 78 is also at atmospheric pressure. On the other hand, since the second slit 74b is closed by the spool 38, the spring housing chamber 78 and the second spool chamber 76b are isolated. Therefore, the first slit 74 a and the second slit 74 b are opened and closed by the spool 38 .

At the second position P2, the air supply port 32 and the second output port 34 communicate, and the first output port 33 and the first exhaust port 35 communicate. Also, the air supply port 32 and the second output port 34 are blocked from the second exhaust port 36, and the first output port 33 and the first exhaust port 35 communicate with the first spool chamber 76a.

Therefore, when the switching valve 24 takes the second position P2, the air supplied from the air supply source 1 through the regulating valve 19 flows from the second output port 34 through the second flow path 4 into the second drive chamber 21b. supplied. At the same time, the air in the first drive chamber 21 a is discharged from the first exhaust port 35 through the first flow path 3 . In the state shown in FIG. 7 or 8, the air in the first spool chamber 76a is discharged from the first exhaust port 35 through the first throttle passage 80a.

By switching the switching valve 24 between the first position P1 and the second position P2, the supply destination of the air is switched to the first drive chamber 21a or the second drive chamber 21b, and the pressure increasing chamber for compressing the air is switched to the first pressure chamber. It is switched to the first pressure increasing chamber 22a or the second pressure increasing chamber 22b. That is, the switching valve 24 switches the first drive chamber 21a to communicate with the first output port 33 or the first exhaust port 35 via the air supply port 32 . Also, the switching valve 24 switches the second drive chamber 21 b to communicate with the second output port 34 or the second exhaust port 36 via the air supply port 32 .

The sleeve 31 has a first rod cover 63a at one end in the X-axis direction and a second rod cover 63b at the other end in the X-axis direction.
The switching valve 24 is surrounded by an inner surface 630a of the first rod cover 63a in the axial direction X, an inner peripheral surface 410 of the first valve seat 41, and an outer surface 610 of the first pressure receiving portion 61 in the axial direction X. It has one spool chamber 76a.

The switching valve 24 is surrounded by an inner end surface 630b of the second rod cover 63b in the axial direction X, an inner peripheral surface 460 of the sixth valve seat 46, and an outer surface 620 of the second pressure receiving portion 62 in the axial direction X. It has a second spool chamber 76b.

Therefore, the switching valve 24 includes a first spool chamber 76a and a second spool chamber 76b that are defined outside both ends of the spool 38 in the axial direction X within the sleeve 31 .
A first rod packing 75a as a sealing member made of resin is arranged via an annular groove inside the first rod cover 63a in the radial direction. A second rod packing 75b as a sealing member made of resin is arranged via an annular groove inside the second rod cover 63b in the radial direction.

The switching mechanism 20 has a first pin 71 and a second pin 72 arranged at both ends of the sleeve 31 in the axial direction X. As shown in FIG.
The first pin 71 has a first tip portion 71a, a first base portion 71b, and a first connection portion 71c. The first tip portion 71a is a rod-shaped tip portion that penetrates the first rod packing 75a and protrudes toward the first piston 15a. The first base portion 71 b is arranged inside the sleeve 31 . The first base portion 71b has a columnar shape positioned radially inward of the spool 38 . The first connection portion 71c has a disc shape connecting the first tip portion 71a and the first base portion 71b in the axial direction X. As shown in FIG.

The first tip portion 71 a of the first pin 71 has a columnar first small diameter portion 711 , a first tapered portion 712 , and a columnar first large diameter portion 713 . The diameter of the first tapered portion 712 increases along the axial direction X from the first small diameter portion 711 toward the first connection portion 71c. The first large diameter portion 713 is continuous with the first tapered portion 712 along the axial direction X. As shown in FIG. The diameter of the first large diameter portion 713 is larger than the diameter of the first small diameter portion 711 . Also, the diameters of the first small diameter portion 711 and the first tapered portion 712 are smaller than the inner diameter of the first rod packing 75a. Therefore, the peripheral surface 711a of the first small diameter portion 711 and the peripheral surface 712a of the first tapered portion 712 do not contact the inner peripheral edge of the first rod packing 75a. Therefore, a flow path is formed between the peripheral surface 711a of the first small diameter portion 711, the peripheral surface 712a of the first tapered portion 712, and the inner peripheral edge of the first rod packing 75a.

Therefore, the first pin 71 takes the open position P4. At the open position P4, the peripheral surface 711a of the first small diameter portion 711 or the peripheral surface 712a of the first tapered portion 712 is not in contact with the inner peripheral edge of the first rod packing 75a. is released, the flow path between the first spool chamber 76a and the first pressure increasing chamber 22a is opened. That is, when the first pin 71 is positioned at the open position P4, the first spool chamber 76a and the first pressure increasing chamber 22a communicate with each other.

On the other hand, the diameter of the first large diameter portion 713 is larger than the inner diameter of the first rod packing 75a. Therefore, the peripheral surface 713a of the first large-diameter portion 713 contacts the inner peripheral edge of the first rod packing 75a, and no flow path is formed between the peripheral surface 713a and the inner peripheral edge of the first rod packing 75a.

Therefore, the first pin 71 assumes the closed position P3. At the closed position P3, the peripheral surface 713a of the first large diameter portion 713 contacts the inner peripheral edge of the first rod packing 75a, and the first spool chamber 76a and the first spool chamber 76a are in a sealed state with respect to the first pin 71 by the first rod packing 75a. 1 Closes the passage to the pressure increasing chamber 22a. That is, when the first pin 71 is positioned at the closed position P3, the first spool chamber 76a and the first pressure increasing chamber 22a are blocked by the first rod packing 75a. Therefore, the first pin 71 can take two positions, a closed position P3 and an open position P4.

When the inner peripheral edge of the first rod packing 75a faces the peripheral surface 712a of the first tapered portion 712 of the first pin 71, the first pressure increase by the first rod packing 75a increases as the diameter of the first tapered portion 712 decreases. The disconnection between the chamber 22a and the first spool chamber 76a is gradually released. Thus, the opening and closing by the first tapered portion 712 reduces wear of the first rod packing 75a.

The second pin 72 has a second tip portion 72a, a second base portion 72b, and a second connection portion 72c. The second tip 72a is a rod-shaped tip that penetrates the second rod packing 75b and protrudes toward the second piston 15b. The second base portion 72b is arranged inside the sleeve 31 . The second base portion 72b has a columnar shape positioned radially inside the spool 38 . The second connection portion 72c has a disc shape connecting the second tip portion 72a and the second base portion 72b in the axial direction X. As shown in FIG.

The second tip portion 72 a of the second pin 72 has a cylindrical second small diameter portion 721 , a second tapered portion 722 , and a cylindrical second large diameter portion 723 . The diameter of the second tapered portion 722 increases along the axial direction X from the second small diameter portion 721 toward the second connecting portion 72c. The second large diameter portion 723 is continuous with the second tapered portion 722 along the axial direction X. As shown in FIG. The diameter of the second large diameter portion 723 is larger than the diameter of the second small diameter portion 721 . Also, the diameters of the second small diameter portion 721 and the second tapered portion 722 are smaller than the inner diameter of the second rod packing 75b. Therefore, the peripheral surface 721a of the second small diameter portion 721 and the peripheral surface 722a of the second tapered portion 722 do not contact the inner peripheral edge of the second rod packing 75b. Therefore, an air flow path is formed between the peripheral surface 721a of the second small diameter portion 721, the peripheral surface 722a of the second tapered portion 722, and the inner peripheral edge of the second rod packing 75b.

Therefore, the second pin 72 takes the open position P6. At the open position P6, the peripheral surface of the second small diameter portion 721 or the second tapered portion 722 is not in contact with the inner peripheral edge of the second rod packing 75b, and the sealing of the second pin 72 by the second rod packing 75b is released. In this state, the flow path between the second spool chamber 76b and the second pressure boosting chamber 22b is opened. That is, when the second pin 72 is positioned at the open position P6, the second spool chamber 76b and the second pressure increasing chamber 22b communicate with each other.

On the other hand, the diameter of the second large diameter portion 723 is larger than the inner diameter of the second rod packing 75b. Therefore, the peripheral surface 723a of the second large diameter portion 723 contacts the inner peripheral edge of the second rod packing 75b, and no flow path is formed between the peripheral surface 723a and the inner peripheral edge of the second rod packing 75b.

Therefore, the second pin 72 assumes the closed position P5. At the closed position P5, the peripheral surface 723a of the second large diameter portion 723 contacts the inner peripheral edge of the second rod packing 75b, and the second spool chamber 76b is sealed against the second pin 72 by the second rod packing 75b. and the second pressure increasing chamber 22b. That is, when the second pin 72 is positioned at the closed position P5, the second spool chamber 76b and the second pressure increasing chamber 22b are blocked by the second rod packing 75b. Therefore, the second pin 72 can take two positions, a closed position P5 and an open position P6.

In a state in which the inner peripheral edge of the second rod packing 75b faces the peripheral surface 722a of the second tapered portion 722 of the second pin 72, as the second tapered portion 722 becomes smaller in diameter, the second pressure is increased by the second rod packing 75b. The blockage between the chamber 22b and the second spool chamber 76b is gradually released. Thus, the wear of the second rod packing 75b is reduced by opening and closing the second tapered portion 722. As shown in FIG.

In this embodiment, the first tip portion 71a of the first pin 71 and the first rod packing 75a are used to open and close the flow path between the first spool chamber 76a of the switching valve 24 and the first pressure increasing chamber 22a. 25a is configured. The second end portion 72a of the second pin 72 and the second rod packing 75b constitute an on-off valve 25b that opens and closes the flow path between the second spool chamber 76b of the switching valve 24 and the second pressure increasing chamber 22b. It is Therefore, in the pressure booster 10, the first spool chamber 76a and the second spool chamber 76b are partitioned by the first pin 71 and the second pin 72, so that the first spool chamber 76a and the second spool chamber 76b receive pressure. It is divided into an operation side and an atmospheric pressure side.

A first tip portion 71a of the first pin 71 and a second tip portion 72a of the second pin 72 function as valve bodies of the on-off valves 25a and 25b. The first rod packing 75a and the second rod packing 75b function as valve seats for the on-off valves 25a and 25b. The first pin 71 and the second pin 72 also function as a mechanical operating shaft of the switching valve 24 by engaging the first connecting portion 71c and the second connecting portion 72c with both ends of the spool 38. .

Here, the spring accommodating chamber 78 partitioned between the first base portion 71b of the first pin 71 and the second base portion 72b of the second pin 72 in the axial direction X will be described. A return spring 79 is housed in the spring housing chamber 78 . One end of the return spring 79 is in contact with the inner end surface 710b in the axial direction X of the first base portion 71b of the first pin 71 . The other end of the return spring 79 is in contact with the inner end surface 720 b of the second pin 72 in the axial direction X. As shown in FIG.

When the first pin 71 is positioned at the open position P4 and the pressurized air rushes into the first spool chamber 76a, the pressurized air moves the first pin 71 and the spool 38 along the axial direction X to the second position. It is pressed towards pin 72 . The return spring 79 is compressed by the first pin 71 . Therefore, a compression reaction force is generated in the return spring 79 . When the spool 38 moves until it contacts the second connection portion 72c of the second pin 72, the movement of the spool 38 toward the second pin 72 is restricted.

When the second pin 72 is positioned at the open position P6 and the pressurized air rushes into the second spool chamber 76b, the pressurized air pushes the second pin 72 and the spool 38 along the axial direction X to the first position. It is pressed towards pin 71 . The return spring 79 is compressed by the second pin 72 . Therefore, a compression reaction force is generated in the return spring 79 . When the spool 38 moves until it contacts the first connection portion 71c of the first pin 71, the movement of the spool 38 toward the first pin 71 is restricted.

The spring force of the return spring 79 is adjusted so that the return force is greater than or equal to the sum of all the forces shown below. The force that determines the spring force is the thrust generated on the rod diameter of the first pin 71 by the pressure in the first pressure-increasing chamber 22a in the closed position P3, and the force of the second pressure-increasing chamber 22b in the closed position P5. A thrust generated in the rod diameter of the second pin 72 due to pressure can be mentioned. Forces that determine the spring force include the sliding resistance between the first rod packing 75a and the first pin 71 and the sliding resistance between the second rod packing 75b and the second pin 72 . Forces that determine the spring force include sliding resistance between the spool 38 and the first pin 71 and sliding resistance between the spool 38 and the second pin 72 .

A first slit 74a as a slit extending in the axial direction X is formed in the outer peripheral surface of the first base portion 71b. One end of the first slit 74a in the axial direction X is located on the outer peripheral surface of the first base portion 71b, and the other end of the first slit 74a in the axial direction X is located on the end surface 710b of the first base portion 71b. The first slit 74a communicates with the spring accommodating chamber 78 at the other end in the axial direction X. As shown in FIG.

Similarly, a second slit 74b as a slit extending in the axial direction X is formed on the outer peripheral surface of the second base portion 72b. One end of the second slit 74b in the axial direction X is located on the outer peripheral surface of the second base portion 72b, and the other end of the second slit 74b in the axial direction X is located on the end surface 720b of the second base portion 72b. The second slit 74b communicates with the spring accommodating chamber 78 at the other end in the axial direction X. As shown in FIG.

When the first pin 71 is displaced from the closed position P3 to the open position P4 and the switching valve 24 is displaced from the first position P1 to the second position P2, the length of the first slit 74a along the axial direction X is It is the length that allows the spring housing chamber 78 and the first spool chamber 76a to communicate with each other. Therefore, the switching valve 24 has a communication position P7 in which the spring housing chamber 78 and the first spool chamber 76a are communicated by the first slit 74a, and a blocking position P8 in which the spring housing chamber 78 and the first spool chamber 76a are blocked. take.

When the second pin 72 is displaced from the closed position P5 to the open position P6 and the switching valve 24 is displaced from the second position P2 to the first position P1, the length of the second slit 74b along the axial direction X is It is the length that allows the spring housing chamber 78 and the second spool chamber 76b to communicate with each other. Therefore, the switching valve 24 has a communication position P9 in which the spring housing chamber 78 and the second spool chamber 76b are communicated by the second slit 74b, and a blocking position P10 in which the spring housing chamber 78 and the second spool chamber 76b are blocked. take.

When the switching valve 24 is positioned at the open position P4 and the communication position P7, the first spool chamber 76a and the spring housing chamber 78 are communicated with each other, and the pressure becomes the same. When the first piston 15a is disengaged from the first pin 71, the compressed state of the return spring 79 is released, and the compression reaction force of the return spring 79 pushes the first pin 71 toward the closed position P3. A pressing force acts.

Similarly, when the switching valve 24 is positioned at the open position P6 and the communication position P9, the second spool chamber 76b and the spring housing chamber 78 are communicated with each other and the pressure becomes the same. When the second piston 15b is separated from the second pin 72, the compressed state of the return spring 79 is released, and the compression reaction force of the return spring 79 moves the second pin 72 toward the closed position P5. A pressing force acts. Therefore, the return spring 79 and the first slit 74a constitute a return mechanism for returning the first pin 71 from the open position P4 to the closed position P3. Similarly, the return spring 79 and the second slit 74b constitute a return mechanism for returning the second pin 72 from the open position P6 to the closed position P5.

<Action>
Next, the operation of this embodiment will be described. In the pressure intensifying device 10, the compression of air in the second pressure intensifying chamber 22b is completed, the switching valve 24 is in the first position P1, the first pin 71 is in the closed position P3, the second pin 72 is in the closed position P5, and The first slit 74a is located at the blocking position P8, the second slit 74b is located at the communicating position P9, and the first piston 15a and the second piston 15b are in the middle of their strokes.

When the pressure of the air in the first pressure increasing chamber 22a is increased, the air supplied from the air supply source 1 passes through the inlet check valve 18a and is supplied to the first pressure increasing chamber 22a.
As shown in FIG. 3 or 4, in a state where the switching valve 24 is positioned at the first position P1, the air supplied from the air supply port 32 passes through the first output port 33 and the first flow path 3 to the first drive valve. It is supplied to the chamber 21a. The air supplied to the first drive chamber 21a presses the first piston 15a toward the first pressure increasing chamber 22a. At the same time, the air supplied from the air supply source 1 passes through the inlet check valve 18a and is supplied to the second pressure increasing chamber 22b. These compress the air in the first pressure increasing chamber 22a.

At this time, the on-off valve 25a of the first pin 71 is positioned at the closed position P3, and the communication between the first pressure increasing chamber 22a and the first spool chamber 76a is cut off. The on-off valve 25b of the second pin 72 is positioned at the closed position P5, and the communication between the second pressure increasing chamber 22b and the second spool chamber 76b is cut off. The first spool chamber 76a and the second spool chamber 76b are connected to the first exhaust port 35 and the second exhaust port 36 by a first throttle channel 80a and a second throttle channel 80b. At this point, the first spool chamber 76a and the second spool chamber 76b are at atmospheric pressure. Also, the first slit 74a of the first pin 71 is located at the blocking position P8, and the spring housing chamber 78 and the first spool chamber 76a are not communicated with each other. The second slit 74b of the second pin 72 is positioned at the communication position P9, the spring housing chamber 78 and the second spool chamber 76b are in communication, and the spring housing chamber 78 is at atmospheric pressure.

As the pressure increasing operation progresses in the state shown in FIG. 3 or 4, the state shown in FIG. 5 or 6 is reached.
As shown in FIG. 5, FIG. 6, or FIG. 11, the first piston 15a is pressed toward the first pressure increasing chamber 22a, and when the first piston 15a pushes the first pin 71, the first rod packing 75a The sealed state of the first pin 71 is released. As a result, the on-off valve 25a is positioned at the open position P4. Then, the pressurized air in the first pressure increasing chamber 22a flows into the first spool chamber 76a at once. At this time, the pressure in the first spool chamber 76a is much higher than the pressure in the second spool chamber 76b, which is atmospheric pressure. Therefore, the air that has flowed into the first spool chamber 76a quickly moves the spool 38 toward the second spool chamber 76b. Then, the switching valve 24 is positioned at the second position P2. As a result, the first spool chamber 76a communicates with the spring housing chamber 78 via the first slit 74a. Further, as the spool 38 moves toward the second spool chamber 76b, communication between the second spool chamber 76b and the spring housing chamber 78 is blocked via the second slit 74b, and the second slit 74b is moved to the blocking position. Located at P10. If the spool 38 cannot be quickly moved by the pressure of the increased air in the first pressure increasing chamber 22a, the spool 38 is moved by the thrust of the first piston 15a.

By positioning the switching valve 24 at the second position P2, the drive chamber controlled by the adjustment valve 19 is switched from the first drive chamber 21a to the second drive chamber 21b, and the pressure controlled by the adjustment valve 19 is increased. The chamber is switched from the first pressure increasing chamber 22a to the second pressure increasing chamber 22b. Then, the directions in which the first piston 15a and the second piston 15b operate are reversed. Then, when the contact between the first piston 15a and the first pin 71 is released, the state shown in FIG. 7 or 8 is obtained.

As shown in FIG. 7, FIG. 8, or FIG. 11, when the switching valve 24 is positioned at the second position P2, the first slit 74a is positioned at the communicating position P7. 78 are in communication. The compression reaction force of the return spring 79 presses the first pin 71 toward the first piston 15a. The first pin 71 moves from the open position P4 toward the closed position P3, and seals between the first pressure increasing chamber 22a and the first spool chamber 76a. As a result, the first piston 15a moves toward the first drive chamber 21a. Then, the volume of the first pressure increasing chamber 22a increases and the pressure tends to decrease. Then, air is supplied from the air supply source 1 to the first pressure increasing chamber 22a through the inlet check valve 18a.

Air supplied from the adjustment valve 19 through the air supply port 32 is supplied through the second output port 34 and the second flow path 4 to the second drive chamber 21b. As a result, the second piston 15b is pressed toward the first pressure increasing chamber 22a. At the same time, the air supplied from the air supply source 1 passes through the inlet check valve 18a and is supplied to the first pressure increasing chamber 22a. Thus, the air in the second pressure increasing chamber 22b is compressed. At this time, the on-off valve 25b of the second pin 72 is positioned at the closed position P5, and the communication between the second pressure increasing chamber 22b and the second spool chamber 76b is cut off. Further, the second slit 74b is located at the blocking position P10, the second spool chamber 76b and the second slit 74b are not communicated with each other, and air is not supplied to the spring accommodating chamber 78.

Also, the residual pressure in the first spool chamber 76a is discharged to the first exhaust port 35 through the first throttle passage 80a. Then, the first spool chamber 76a and the spring housing chamber 78 are brought to atmospheric pressure.
As the pressure increasing operation progresses in the state shown in FIG. 5, the state shown in FIG. 6 is reached.

As shown in FIG. 9, FIG. 10, or FIG. 11, when the second piston 15b pushes the second pin 72, the sealing state of the second pin 72 by the second rod packing 75b is released, and the second pin 72 opens and closes. The valve 25b is located at the open position P6. Then, the pressurized air in the second pressure increasing chamber 22b flows into the second spool chamber 76b at once. At this time, the pressure in the second spool chamber 76b is much higher than the pressure in the first spool chamber 76a, which is atmospheric pressure. Therefore, the air that has flowed into the second spool chamber 76b quickly moves the spool 38 toward the first spool chamber 76a. Then, the switching valve 24 is positioned at the first position P1. Thereby, the second spool chamber 76b communicates with the spring housing chamber 78 via the second slit 74b. Further, as the spool 38 moves toward the first spool chamber 76a, communication between the first spool chamber 76a and the spring housing chamber 78 is blocked through the first slit 74a, and the first slit 74a is at the blocking position. Located on P8. If the spool 38 cannot be quickly moved by the pressure of the increased air in the second pressure increasing chamber 22b, the spool 38 is moved by the thrust of the second piston 15b.

Positioning the switching valve 24 at the first position P1 switches the drive chamber controlled by the adjustment valve 19 from the second drive chamber 21b to the first drive chamber 21a, and increases the pressure controlled by the adjustment valve 19. The chamber is switched from the second pressure increasing chamber 22b to the first pressure increasing chamber 22a. Then, the directions in which the first piston 15a and the second piston 15b operate are reversed. Then, when the contact between the second piston 15b and the second pin 72 is released, the state shown in FIG. 3 or 4 is obtained.

3 or 4 to the state shown in FIG. 9 or 10 until the compressed air reaches the pressure set by the regulating valve 19. By repeating the switching operation of the second pressure increasing chamber 22a and the second pressure increasing chamber 22b, the pressure increasing operation is continuously performed.

The regulating valve 19 compares the set pressure and the discharge pressure, and adjusts the valve opening of the regulating valve 19 according to the deviation. This adjusts the flow rate of air supplied to the first drive chamber 21a and the second drive chamber 21b. When the set pressure and the discharge pressure match, the regulating valve 19 stops the supply to the first drive chamber 21a and the second drive chamber 21b. In this manner, the output pressure of the discharge port 2 is adjusted to the set pressure.

<effect>
In the above embodiment, the following effects can be obtained.
(1) In the pressure intensifying device 10, the on-off valves 25a and 25b of the switching mechanism 20 are positioned at the open position, so that the pressure of the air intensified in the pressure intensifying chamber moves the spool 38 all at once, and furthermore, the moving speed of the piston increases. is slowed down, it can be moved by fluid drive. Therefore, the switching speed of the spool 38 can be increased. As a result, compared to the case where the spool 38 is moved by pressing the first pin 71 by the first piston 15a or by pressing the second pin 72 by the second piston 15b, the operating speed of the spool 38 can be increased, and the switching valve 24 can be suppressed from stopping at the neutral position.

(2) The pressure booster 10 can also move the spool 38 by mechanical operation using the first pin 71 or the second pin 72 . For example, when the movement of the spool 38 due to the pressure of the air is unstable, such as when the pressure of the supplied air is low, the first pin 71 and The thrust of the second pin 72 can also move the spool 38 . That is, the switching valve 24 is switched by the switching operation by the air pressure or the switching operation by the thrust of the first pin 71 and the second pin 72, whichever is faster. As a result, the reliability of the pressure booster 10 is improved, and the switching speed of the switching valve 24 is improved.

(3) In the pressure booster 10, the spool chamber located at the movement destination of the spool 38 can be communicated with the exhaust port. Therefore, residual pressure is less likely to remain in the spool chamber located at the destination of the movement of the spool 38 , and the residual pressure is less likely to hinder the movement of the spool 38 . As a result, the intensifier 10 can continue to alternate spools 38 at a fast rate until the set pressure is reached. Therefore, it is possible to prevent the switching valve 24 from stopping at the neutral position.

(4) Since the first pin 71 has the first slit 74a, after the spool 38 is pressed by the air introduced from the first pressure increasing chamber 22a to the first spool chamber 76a, the first pin 71 passes through the first slit 74a. The first spool chamber 76a and the spring housing chamber 78 communicate with each other. Then, the first spool chamber 76a and the spring housing chamber 78 have the same pressure, and the thrust of the first pin 71 due to the pressure in the first spool chamber 76a can be suppressed, so that the compressed return spring 79 is easily returned. Become.

Similarly, since the second pin 72 has the second slit 74b, after the spool 38 is pressed by the air introduced from the second pressure increasing chamber 22b to the second spool chamber 76b, the air flows through the second slit 74b. The second spool chamber 76b and the spring housing chamber 78 communicate with each other. Then, the second spool chamber 76b and the spring housing chamber 78 have the same pressure, and the thrust of the second pin 72 due to the pressure in the second spool chamber 76b can be suppressed, so that the compressed return spring 79 is easily returned. Become.

(5) The pressure booster 10 has a first throttle channel 80a and a second throttle channel 80b for discharging air to the atmosphere. Therefore, the switching valve 24 functions as a three-way valve with the opening/closing valves 25a and 25b and the first throttle channel 80a and the second throttle channel 80b.

(6) The first throttle channel 80a is formed by the fitting gap between the first pressure receiving portion 61 and the first valve seat 41, and the second throttle channel 80b is formed by the second pressure receiving portion 62 and the first valve seat 41. 6 is constituted by the fitting clearance between the valve seat 46 and the valve seat 46 . Therefore, the switching valve 24 can be made to function as a three-way valve without providing a restricted flow path in addition to the fitting gap between the sleeve 31 and the spool 38 . Therefore, the configuration of the switching valve 24 can be simplified as compared with the case where the throttle channel is provided separately from the fitting gap between the sleeve 31 and the spool 38 .

(7) The pressure booster 10 can prevent the spool 38 from stopping at the neutral position simply by providing the on-off valves 25a and 25b to the existing structure having the first pin 71 and the second pin 72 . Therefore, it is possible to prevent the switching valve 24 from stopping at the neutral position simply by processing the first pin 71 and the second pin 72 . As a result, the manufacturing cost of the pressure intensifying device 10 can be reduced while suppressing an increase in the size of the pressure intensifying device 10 .

(8) In the pressure booster 10, the first spool chamber 76a and the second spool chamber 76b are partitioned by the first pin 71 and the second pin 72, thereby separating the first spool chamber 76a and the second spool chamber 76b. It is divided into a pressure receiving side and an atmospheric pressure side. Therefore, for example, compared to the case where the first spool chamber 76a and the second spool chamber 76b are divided into the pressure receiving operation side and the atmospheric pressure side by a member other than the first pin 71 and the second pin 72, the pressure increasing The structure of the device 10 can be simplified.

<Change example>
This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- As shown in FIG. 13 , the opening/closing valve 25 a of the first pin 71 is not limited to the configuration in which the first tip portion 71 a has the first tapered portion 712 . For example, a configuration may be employed in which a slit 80 extending in the axial direction X is provided in a portion of the first tip portion 71a of the first pin 71 in the circumferential direction. Although not shown, the on-off valve 25b of the second pin 72 may have a configuration in which a slit extending in the axial direction X is provided in a part of the second tip portion 72a in the circumferential direction.

・ As shown in FIG. 14, the opening/closing valve 25a of the first pin 71 is formed by a valve seat 82 provided at a position surrounding the first tip portion 71a on the inner surface 630a of the first rod cover 63a, and the first connecting portion 71c. , and a valve portion 81 that can be seated on the valve seat 82 .

In this case, when the valve portion 81 is seated on the valve seat 82, the valve seat 82 forms a sealing state with respect to the first pin 71, and the closed position is formed. At this closed position, the flow path between the first pressure increasing chamber 22a and the first spool chamber 76a is blocked.

When the first pin 71 is pushed into the first piston 15a and the valve portion 81 is separated from the valve seat 82, the seal against the first pin 71 by the valve seat 82 is released, thereby forming the open position. At this open position, the first pressure increasing chamber 22a and the first spool chamber 76a communicate with each other.

- In the embodiment, the first throttle channel 80 a may be provided separately from the fitting gap between the first pressure receiving portion 61 and the first valve seat 41 .
- In the embodiment, the second throttle channel 80 b may be provided separately from the fitting gap between the second pressure receiving portion 62 and the sixth valve seat 46 .

- In embodiment, the 1st base 71b is not restricted to the structure which has the 1st slit 74a. The point is that, when the spool 38 is pushed to one end, the spool chamber of the pushed side communicates with the exhaust port, so that the residual pressure is exhausted.

In the embodiment, the timing at which the first pressure increasing chamber 22a and the first spool chamber 76a communicate is from the moment the first piston 15a contacts the first pin 71 to just before the first pin 71 contacts the spool 38. If so, any timing is acceptable.

- In the embodiment, the outer peripheral surface 61a of the first pressure receiving portion 61 in the radial direction and the inner peripheral surface 410 of the first valve seat 41 may be sealed by a sealing member such as a packing seal. Similarly, the outer peripheral surface 62a of the second pressure receiving portion 62 in the radial direction and the inner peripheral surface 460 of the sixth valve seat 46 may be sealed by a sealing member such as a packing seal. In this case, the first throttle channel 80a and the second throttle channel 80b, which are gaps to the atmosphere shown in the embodiment, need to be provided separately from the fitting gap. A detent effect can be expected when packing seals are used.

- In the embodiment, the spool 38 is not limited to being made of metal, and may be made of resin, for example.

DESCRIPTION OF SYMBOLS 10... Pressure booster 13... Main body block 14a... First cylinder chamber as a cylinder chamber 14b... Second cylinder chamber as a cylinder chamber 15a... First piston as a piston 15b... Second piston as a piston , 16... Shaft member 21a... First drive chamber as a drive chamber 21b... Second drive chamber as a drive chamber 22a... First pressure increase chamber as a pressure increase chamber 22b... Second pressure increase chamber as a pressure increase chamber Pressure increasing chamber 24 Switching valve 25a, 25b On-off valve 31 Sleeve 32 Air supply port 33 First output port as output port 34 Second output port as output port 35 First exhaust port as an exhaust port, 36... Second exhaust port as an exhaust port, 38... Spool, 41... First valve seat as a valve seat, 42... Second valve seat as a valve seat, 61... Pressure receiving portion 62... Second pressure receiving part as pressure receiving part 71... First pin as pin 72... Second pin as pin 71a... First tip part as tip part 71b... Base part 72a... second tip as tip part, 72b... second base as base part, 74a... first slit as slit, 74b... second slit as slit, 75a... as seal member First rod packing 75b Second rod packing as a sealing member 76a First spool chamber as a spool chamber 76b Second spool chamber as a spool chamber 78 Spring housing chamber 79 Return spring 80a .

Claims (6)

a body block;
a pair of cylinder chambers sandwiching the main body block;
a shaft member passing through the main body block;
a piston connected to both ends of the shaft member and arranged in each cylinder chamber;
In each cylinder chamber, a pressure increasing chamber located on the main block side with respect to the piston, and a drive chamber located on the opposite side to the pressure increasing chamber;
a switching valve that is driven by the pressing of the pin by each of the pistons to switch and communicate each of the drive chambers with an output port or an exhaust port via an air supply port;
a sleeve including the air supply port, the exhaust port, and the output port;
a spool axially reciprocating within the sleeve;
a spool chamber defined outside both ends of the spool in the axial direction within the sleeve;
a pair of said pins partially disposed in said respective spool chambers and having distal ends penetrating said sleeve in said axial direction;
a return spring housed in a spring housing chamber disposed between the pair of axial pins;
A pressure booster comprising a seal member for sealing between the tip of each pin and the sleeve,
an on-off valve that assumes an open position that allows communication between the pressure increasing chamber and the spool chamber and a closed position that isolates the pressure increasing chamber and the spool chamber,
The closed position is formed by a sealing condition with respect to the pin by the sealing member,
the open position is formed by releasing the seal against the pin by the seal member;
When the on-off valve is in the closed position, the on-off valve is opened until the pin is pressed by the piston and the air supply port communicates with an output port different from the output port to which the on-off valve communicates. A pressure intensifier, characterized in that: The pin is
a base disposed within the spool;
a slit provided in the base and extending in the axial direction;
2. The pressure booster according to claim 1, wherein the slit communicates the spool chamber and the spring housing chamber according to the position of the spool in the switching valve. The spool has a pressure receiving portion that receives air introduced from the pressure increasing chamber to the spool chamber,
the sleeve has a valve seat on which the pressure receiving portion is seated to seal the spool chamber;
3. The pressure booster according to claim 1, wherein the pressure receiving portion and the valve seat are metal-sealed. The switching valve has a throttle channel connecting the spool chamber and the exhaust port,
The pressure booster according to any one of claims 1 to 3, wherein air in the spool chamber is exhausted through the throttle channel when the on-off valve takes the closed position. 5. The pressure booster according to claim 4, wherein the throttle channel is a fitting gap between the sleeve and the spool. The switching valve has a valve seat that seals with the pressure increasing chamber, and is switched by moving the spool due to the thrust of the pin,
6. The switching operation according to any one of claims 1 to 5, wherein the switching operation is performed by the switching operation by the fluid supplied from the pressure increasing chamber or the switching operation by the thrust force of the pin, whichever is faster. A pressure intensifier according to any one of the preceding paragraphs.

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