BR112021002800A2 - pressure intensifier - Google Patents

Abstract

PRESSURE Boost. A pressure intensifier (10) in which actuating cylinders (14, 16) are arranged on both sides of an intensifying cylinder (12), and which is equipped with: a pair of pilot valves (72, 74) equipped with impact pins (90) that contact the pistons (36, 38) of the drive cylinders at a moving end; and a pair of actuating valves (48, 52) for switching the supply state of a pressure fluid with respect to the pressure chambers (24a, 26a) of the actuating cylinders. When a piston presses against an impact pin and one or the other pilot valve thus switches to a first position, the state in which pressure fluid is supplied to the pair of actuation valves is switched and a prescribed fluid pressure acts on the pin of impact mode to keep the pilot valve in the first position.

Description

PRESSURE Boost Technical field

[0001] The present invention relates to a pressure intensifier to increase the pressure of a pressurized fluid and emit the pressurized fluid. Background

[0002] Conventionally, pressure intensifier devices are known that consecutively increase the pressure of pressurized fluid by reciprocating the pistons and then release the pressurized fluid.

[0003] For example, Japanese Patent Publication No. 08-021404 discloses a pressure intensifier in which a pair of intensifying cylinders having their respective pistons directly connected to a piston rod are arranged so as to face one another. another, and an energy collection cylinder is provided between the pair of boost cylinders. In this pressure intensifier, compressed air is supplied to the compression chamber and operating chamber of one of the intensifying cylinders and to the compression chamber of the other intensifying cylinder, and then the air supplied to the compression chamber of that cylinder. intensifying is intensified and emitted. The air supply switching operation between the intensifying cylinders and the flow channels connected to the collection cylinder is performed by reed switches that detect the positions of the pistons in the intensifying cylinders to thus turn on and off solenoids of a switching valve accordingly.

[0004] In the pressure intensifier of Japanese Patent Publication No. 08-021404, the pair of intensifying cylinders each has the operating chamber to drive the piston and the compression chamber to compress the fluid. This can limit design flexibility. In addition, as reed switches and solenoids are used to carry out the switching operation, electrical means including electrical wiring are required.

[0005] Consequently, the applicant of the present invention has filed a patent application for an invention relating to a pressure intensifier in which cylinders for driving the pistons and a cylinder for pressurized fluid compression are separately arranged in an organized manner, and which is capable of performing switching operations without the use of electrical means (Japanese Patent Application No. 2017-164945).

[0006] The pressure intensifier of the above patent application includes drive cylinders provided respectively on both sides of an intensifier cylinder, a pair of pilot valves each having a thrust rod with which the corresponding drive cylinder piston contacts at its displacement end, and a pair of operating valves to switch the pressurized fluid supply state from a pressurized fluid supply source to the pressurization chambers of the individual drive cylinders. Invention Summary

[0007] With the pressure intensifier of the above patent application, the force with which the piston of each drive cylinder pushes the thrust rod becomes weak, for example, when the output of the pressure intensifier becomes close to the saturation, and then the push rod can be disadvantagedly returned by the spring force without the pilot valve being sufficiently switched. The pressure intensifier was therefore not entirely satisfactory. The present invention was conceived considering such a situation, and an object of the present invention is to provide a pressure intensifier capable of reliably switching pilot valves even when the pistons of the actuating cylinders push the pilot valves with a weak force.

[0008] According to the present invention, a pressure intensifier in which drive cylinders are respectively provided on both sides of an intensifying cylinder includes: a pair of pilot valves each including an impact pin with which a piston from a corresponding one of the drive cylinders contacts a displacement end of the piston, and a pair of operating valves each configured to switch the supply state of a pressurized fluid from a pressurized fluid supply source to a chamber pressurization of a corresponding one of the drive cylinders. When either of the pilot valves switches to a first position by the pilot valve impact pin being pushed by the corresponding piston, then the supply state of the pressurized fluid to the pair of operating valves is switched and a certain fluid pressure acts on the impact pin to hold the pilot valve in the first position.

[0009] According to the above pressure intensifier, an impact pin that has come into contact with the drive cylinder piston can be pushed all the way out by certain fluid pressure, and the pilot valve can be held in a position fully switched.

[00010] According to the pressure intensifier of the invention, a certain fluid pressure acts on the impact pins so as to keep the pilot valves in fully switched positions. Consequently, even if the piston of a drive cylinder pushes the impact pin with a weak force, the impact pin can be pushed all the way in and the pilot valve can be reliably switched. Brief Description of Drawings

[00011] FIG. 1 is a perspective view illustrating the appearance of a pressure enhancer in accordance with an embodiment of the present invention; FIG. 2 is a side view of the pressure intensifier of FIG. 1; FIG. 3 is a cross-sectional view taken along III-III of FIG. two; FIG. 4 is a cross-sectional view taken along IV-IV of FIG. two; FIG. 5 is a general schematic diagram illustrating the pressure enhancer of FIG. 1 using a circuit diagram; FIG. 6 is a cross-sectional view of a first pilot valve of the pressure intensifier of FIG. 1; FIG. 7 is a diagram corresponding to FIG. 6, where the impact pin of the first pilot valve has moved to a different position;

FIG. 8 is a diagram corresponding to FIG. 6, where the impact pin of the first pilot valve has moved further to a different position; and FIG. 9 is a diagram corresponding to FIG. 5, where the pressure enhancer has switched from the state of FIG. 5 to another state. Description of Modalities

[00012] The pressure intensifier of the present invention will be described below in detail in connection with preferred embodiments while referring to the accompanying drawings. A pressure intensifier 10 in accordance with an embodiment of the invention is installed between a pressurized fluid supply source (compressor; not shown) and an actuator (not shown) which operates with the pressurized fluid whose pressure has been increased.

[00013] As shown in FIGS. 1 and 3, the pressure intensifier 10 has a triple cylinder structure including an intensifying cylinder 12, a first drive cylinder 14 disposed at one end of the intensifying cylinder 12 (one end on an A1 direction side), and a second drive cylinder 16 arranged at the other end of the intensifying cylinder 12 (one end on a direction side A2), which are connected in a row. That is, in the pressure intensifier 10, the first drive cylinder 14, the intensifier cylinder 12, and the second drive cylinder 16 are arranged in this order from direction A1 to direction A2.

[00014] A first cap member 18 in the form of a block is interposed between the first drive cylinder

14 and intensifying cylinder 12, and a second cap member 20 in the form of a block is interposed between intensifying cylinder 12 and second driving cylinder 16.

[00015] The intensifying cylinder 12 includes an intensifying chamber 22 therein, and the first driving cylinder 14 and the second driving cylinder 16 include a first driving chamber 24 and a second driving chamber 26 therein, respectively. In this case, a third cap member 28 is fixed at one end of the first drive cylinder 14 at side A1, and the first cap member 18 is disposed at one end thereof at side A2, thus forming the first drive chamber.

24. In addition, the second cover member 20 is disposed at one end of the second drive cylinder 16 at side A1, and one end thereof at side A2 is closed off by a wall 30, thus forming the second drive chamber.

26.

[00016] As shown in FIG. 3, a piston rod 32 is provided to pass through the first cap member 18, the intensifying cylinder 12, and the second cap member 20. One end of the piston rod 32 extends into the first actuating chamber 24, and the other end of the piston rod 32 extends to the second actuating chamber 26.

[00017] In the intensifying chamber 22, an intensifying piston 34 is coupled to an intermediate portion of the piston rod 32. The intensifying chamber 22 is therefore divided into a first intensifying chamber 22a on the A1 side and a second intensifying chamber 22b on side A2 (see FIG. 5). In the first actuation chamber 24, a first actuation piston 36 is coupled to one end of the piston rod 32. The first actuation chamber 24 is then divided into a pressurizing chamber 24a on the A1 side and a back pressure chamber 24b on the side A2 (see FIG. 5). Furthermore, in the second actuating chamber 26, a second actuating piston 38 is coupled to the other end of the piston rod 32. The second actuating chamber 26 is therefore divided into a pressurizing chamber 26a on the A2 side and a back pressure chamber. 26b on side A1 (see FIG. 5). Intensifying piston 34, first actuating piston 36, and second actuating piston 38 are integrally connected through piston rod 32.

[00018] As shown in FIG. 1, intensifying cylinder 12 includes, on an upper portion of the front surface, a supply port 40 to which pressurized fluid is supplied from a pressurized fluid supply source (not shown). As shown in FIGS. 4 and 5, a fluid feed mechanism is provided within the intensifying cylinder 12, the first cover member 18, and the second cover member 20. The fluid feed mechanism communicates with the feed port 40 and supplies the pressurized fluid supplied to the first intensifying chamber 22a and the second intensifying chamber 22b. The fluid feed mechanism includes a first feed port 42a that allows the feed port 40 and the first intensifying chamber 22a to communicate with each other, and a second feed passage 42b that allows the feed port 40 and the second intensifying chamber 22b communicate with each other.

[00019] The first feed passage 42a is provided with a first feed check valve 42c which allows fluid flow from the feed port 40 to the first intensifying chamber 22a and blocks fluid flow from the first intensifying chamber 22a to the feed port 40. The second feed passage 42b is provided with a second feed check valve 42d which permits fluid flow from the feed port 40 to the second intensifying chamber 22b and blocks fluid flow from the second intensifying chamber 22b to feed port 40.

[00020] As shown in FIG. 1, intensifying cylinder 12 includes an outlet port 44 formed in a lower portion of the front surface. The fluid whose pressure is intensified by the intensifying operation, which will be described later, is sent from the outlet port 44 to the outside. As shown in FIGS. 4 and 5, a fluid outlet mechanism is provided within the intensifying cylinder 12, the first cap member 18, and the second cap member 20. The fluid outlet mechanism communicates with the outlet port 44, and emits, from the outlet port 44, fluid whose pressure has been intensified in the first intensifying chamber 22a or in the second intensifying chamber 22b. The fluid outlet mechanism includes a first outlet passage 46a that allows the first intensifier chamber 22a and outlet port 44 to communicate with each other, and a second outlet passage 46b that allows the second intensifier chamber 22b and output port 44 communicate with each other.

[00021] The first outlet passage 46a is provided with a first outlet check valve 46c which allows fluid flow from the first intensifying chamber 22a to the outlet port 44 and blocks fluid flow from the outlet port 44 to the first intensifying chamber 22a. The second outlet passage 46b is provided with a second outlet check valve 46d which allows fluid flow from the second intensifying chamber 22b to the outlet port 44 and blocks fluid flow from the outlet port 44 to the second chamber. of intensification 22b.

[00022] Next, a configuration of the operating valves will be described. As shown in FIG. 1, the first actuating cylinder 14 includes, at an upper part thereof, a first housing 50 having a first operating valve 48, and the second actuating cylinder 16 includes, at an upper part thereof, a second housing 54 having a second operating valve 52.

[00023] As shown in FIG. 5, the first operating valve 48 has first through fifth ports 56A to 56E as port switching and connection points. The first operating valve 48 is configured to be able to switch between a first position to actuate the first actuating piston 36 and a second position to allow the first actuating piston 36 to follow the movement of the second actuating piston 38 being triggered.

[00024] The first port 56A is connected to the pressurizing chamber 24a on the first drive cylinder 14 through a passage 58a. The second port 56B is connected to the back pressure chamber 24b in the first drive cylinder 14 through a passage 58b. The third port 56C is connected to the first feed passage 42a via a passage 58c. The fourth port 56D is connected through a passage 58d to a first silencer 62 having an exhaust port. Fifth port 56E is connected to an intermediate point of passageway 58a through passageway 58e. Passage 58d has a first fixed hole 60 interposed therein.

[00025] When the first operating valve 48 is in the first position, the first port 56A and the third port 56C communicate with each other, and the second port 56B and the fourth port 56D communicate with each other. Then, pressurized fluid from the supply port 40 is supplied to the pressurizing chamber 24a through passage 58c and passage 58a, and the fluid in the back pressure chamber 24b is discharged through passage 58b and passage 58d and through the first fixed orifice. 60 and the first silencer 62.

[00026] When the first operating valve 48 is in the second position, the first port 56A and the fourth port 56D communicate with each other, and the second port 56B and the fifth port 56E communicate with each other. Then, part of the fluid in pressurizing chamber 24a is collected in backpressure chamber 24b through passage 58a, passage 58e, and passage 58b, and the remainder is discharged through passage 58d and through first fixed orifice 60 and first silencer 62.

[00027] The first operating valve 48 further includes a pilot port 56F for introducing pilot pressure from a second pilot valve 74 which will be described later. The first operating valve 48 is in the first position when pressurized fluid (pilot pressure) is being supplied to pilot port 56F, and is in the second position when pressurized fluid (pilot pressure) is not being supplied to pilot port 56F.

[00028] The second operating valve 52 has first through fifth ports 64A to 64E as port switching and connection points. The second operating valve 52 is configured to be able to switch between a first position to actuate the second actuating piston 38 and a second position to allow the second actuating piston 38 to follow the movement of the first actuating piston 36 being triggered.

[00029] The first port 64A is connected to the pressurizing chamber 26a in the second drive cylinder 16 through a passage 66a. The second port 64B is connected to the back pressure chamber 26b in the second drive cylinder 16 through a passage 66b. The third port 64C is connected to the second feed passage 42b via a passage 66c. The fourth port 64D is connected through a passage 66d to a second silencer 70 having an exhaust port. Fifth port 64E is connected to an intermediate point of passage 66a through passage 66e. Pass 66d has a second fixed hole 68 interposed therein.

[00030] When the second operating valve 52 is in the first position, the first port 64A and the third port 64C communicate with each other, and the second port 64B and the fourth port 64D communicate with each other. Thereafter, the pressurized fluid from the supply port 40 is supplied to the pressurizing chamber 26a through passage 66c and passage 66a, and the fluid in the back pressure chamber 26b is discharged through passage 66b and passage 66d and through the second fixed orifice. 68 and the second silencer 70.

[00031] When the second operating valve 52 is in the second position, the first port 64A and the fourth port 64D communicate with each other, and the second port 64B and the fifth port 64E communicate with each other. Then, part of the fluid in pressurizing chamber 26a is collected in backpressure chamber 26b through passage 66a, passage 66e, and passage 66b, and the remainder is discharged through passage 66d and through second fixed orifice 68 and second silencer 70.

[00032] The second operating valve 52 further includes a pilot port 64F for introducing pilot pressure from a first pilot valve 72 which will be described later. The second operating valve 52 is in the first position when pressurized fluid (pilot pressure) is being supplied to pilot port 64F, and is in the second position when pressurized fluid (pilot pressure) is not being supplied to pilot port 64F.

[00033] Next, a configuration of the pilot valves will be described. First pilot valve 72 is provided within first cap member 18, and second pilot valve 74 is provided within second cap member 20.

[00034] The first pilot valve 72 has first through fourth ports 76A to 76D. The first pilot valve 72 is configured to be able to switch between a first position to generate pilot pressure for the second operating valve 52 and a second position to eliminate pilot pressure.

[00035] The first port 76A is connected to the pilot port 64F of the second operating valve 52 through a first pilot passage 78b. The second port (feed port) 76B is connected to the first feed passage 42a via a passage 78a. The third port 76C constitutes a discharge port. The fourth port (cooperating port) 76D is connected to a first port 80A of the second pilot valve 74, which will be described later, through a branch passage 82c and a second pilot passage 82b described later. In addition, a branch passage 78c connecting to a fourth port 80D of the second pilot valve 74, which will be described later, branches from the first pilot passage 78b.

[00036] When the first pilot valve 72 is in the first position, the first port 76A and the second port 76B communicate with each other. Thereafter, pressurized fluid from supply port 40 is supplied to pilot port 64F of second operating valve 52 through passage 78a, and first pilot passage 78b, and pressurized fluid is also supplied to fourth port 80D of second pilot valve. 74 (described later) through branch passage 78c branching from first pilot passage 78b.

[00037] When the first pilot valve 72 is in the second position, the first port 76A and the third port 76C communicate with each other. Then, pressurized fluid that was supplied to pilot port 64F of second operating valve 52 is discharged through first pilot passage 78b, and pressurized fluid supplied to fourth port 80D of second pilot valve 74 is discharged through branch passage 78c and first pilot pass 78b.

[00038] The second pilot valve 74 has first through fourth ports 80A to 80D. Second pilot valve 74 is configured to be able to switch between a first position to generate pilot pressure for first operating valve 48 and a second position to eliminate pilot pressure.

[00039] The first port 80A is connected to the pilot port 56F of the first operating valve 48 through the second pilot passage 82b. The second port (feed port) 80B is connected to the second feed passage 42b via a passage 82a. The third port 80C constitutes a discharge port. Fourth port 80D (cooperating port) is connected to first port 76A of first pilot valve 72 through branch passage 78c and first pilot passage 78b. In addition, the branch passage 82c connecting to the fourth port 76D of the first pilot valve 72 branches from the second pilot passage 82b.

[00040] When the second pilot valve 74 is in the first position, the first port 80A and the second port 80B communicate with each other. Thereafter, pressurized fluid from supply port 40 is supplied to pilot port 56F of first operating valve 48 through passage 82a and second pilot passage 82b, and pressurized fluid is also supplied to fourth port 76D of first pilot valve 72 through the branch passage 82c which branches from the second pilot passage 82b.

[00041] When the second pilot valve 74 is in the second position, the first port 80A and the third port 80C communicate with each other. Then, pressurized fluid that was supplied to pilot port 56F of first operating valve 48 is discharged through second pilot passage 82b, and pressurized fluid supplied to fourth port 76D of first pilot valve 72 is discharged through branch passage 82c. and second pilot run 82b.

[00042] Now, with reference to FIGS. 6-8, a specific structure of the first pilot valve 72 will be described. The second pilot valve 74 has the same structure as the first pilot valve 72, and therefore will not be described here.

[00043] The first pilot valve 72 includes a valve seat 86 accommodated in a valve container hole 84 formed in the first cap member 18, a valve seat retainer 88, and an impact pin 90. The container hole valve 84 is closed on the side of the intensifying cylinder 12 and opens on the side of the first drive cylinder 14. The valve container hole 84 includes, at the closed end, a large diameter hole portion 84a, and the fourth port 76D communicates with this large diameter bore portion 84a.

[00044] The valve container bore 84 further has a small diameter bore portion 84b connecting to the large diameter bore portion 84a and a medium diameter bore portion 84c disposed on the opening side of the valve container bore and connecting to the small diameter hole portion 84b. The first port 76A, the second port 76B and the third port 76C communicate with the small diameter bore portion 84b of the valve container bore 84. Of these three ports, the second port 76B is located closest to the fourth port 76D, and the third port 76C is located farther away from the fourth port 76D.

[00045] The valve seat 86 having a thin wall cylindrical shape, and the valve seat retainer 88 having a thick wall cylindrical shape are inserted and fitted in the small diameter bore portion 84b of the valve container bore 84 The valve seat retainer 88 includes an end surface located at one end in the axial direction and another end surface located at the other end in the axial direction, the one end surface facing the back pressure chamber 24b of the first drive cylinder 14, the other end surface abutting the valve seat 86. A snap ring 92 abutting the valve seat retainer 88 is secured to the medium diameter bore portion 84c of the valve container bore 84. The valve seat 86 and the valve seat retainer 88 are thus positioned and secured in the axial direction within the valve container bore 84. The valve seat 86 is engaged and locked with a step f formed at an intermediate position of the small diameter hole portion 84b.

[00046] An annular groove 86a facing the first port 76A is formed on the outer periphery of a middle portion of the valve seat 86 in the axial direction, and an annular recess 86b facing the third port 76C is formed on the outer periphery of one end valve seat 86 in the axial direction on one side that abuts the valve seat retainer

88. The annular groove 86a of the valve seat 86 communicates with the inner peripheral side of the valve seat 86 through a first through hole 86c which penetrates through the valve seat 86 in the radial direction, and the annular recess 86b of the seat The valve seat 86 communicates with the inner peripheral side of the valve seat 86 through a second through hole 86d which penetrates through the valve seat 86 in the radial direction.

[00047] A first sealing member 94a and a second sealing member 94b abutting against the small diameter bore portion 84b of the valve container bore 84 are fitted into grooves formed in the outer peripheral surface of the valve seat 86. first sealing member 94a prevents first port 76A and second port 76B from communicating with each other through the clearance between valve seat 86 and valve container bore 84, and second sealing member 94b prevents first port 76A and the third port 76C to communicate with each other through the clearance between the valve seat 86 and the valve container bore.

84.

[00048] A third sealing element 96a abutting the small diameter bore portion 84b of the valve container bore 84 is fitted in a groove formed in the outer peripheral surface of the valve seat retainer 88, and a fourth sealing element 96b in sliding contact with the impact pin 90 is fitted into a groove formed in the inner peripheral surface of the valve seat retainer 88. The third sealing member 96a and the fourth sealing member 96b provide a seal between the third port 76C and the back pressure chamber 24b of the first drive cylinder 14.

[00049] The impact pin 90 has a large diameter shaft portion 90a, a medium diameter shaft portion 90b, and a small diameter shaft portion 90c. The large diameter shaft portion 90a is inserted and fitted into the small diameter bore portion 84b of the valve container bore 84. The medium diameter shaft portion 90b is inserted and fitted into the valve seat 86 in such a manner that part of the shaft portion 90b projects from the valve seat 86, and the part that projects from the valve seat 86 faces the small diameter bore portion 84b of the valve container bore 84 in a certain range in the radial direction. The small diameter shaft portion 90c is inserted and fitted into the valve seat retainer 88.

[00050] A first gasket 98a in sliding contact with the small diameter bore portion 84b of the valve container bore 84 is fitted in a groove formed in the large diameter shaft portion 90a of the impact pin

90. The first gasket 98a provides a seal between the second port 76B and the fourth port 76D. A second gasket 98b and a third gasket 98c which may be in sliding contact with the inner peripheral surface of the valve seat 86 are fitted into grooves formed in the mid-diameter shaft portion 90b of the impact pin 90. The mid-diameter shaft 90b of the impact pin 90 has, formed therein, an annular groove 90d between the portion where the second gasket 98b is fitted and the portion where the third gasket 98c is fitted.

[00051] The impact pin 90 can slide between a position where its end on the large diameter shaft portion 90a contacts the lower surface (closed end surface) of the valve container bore 84 and a position where a step surface 90e between the medium diameter shaft portion 90b and the small diameter shaft portion 90c contacts the end surface of the valve seat retainer 88. When the impact pin 90 contacts the end surface of the valve seat retainer 88, the length that the small diameter shaft portion 90c of the impact pin 90 projects into the back pressure chamber 24b of the first drive cylinder 14 (hereinafter referred to as "impact pin projection length") becomes maximum. The first drive piston 36 contacts the end of the impact pin 90 on its small diameter shaft portion 90c and presses the impact pin 90 towards the lower surface of the bore d and valve container 84.

[00052] The annular groove 90d of the impact pin 90 communicates with the annular groove 86a through the first through hole 86c in the valve seat 86, regardless of the projection length of the impact pin 90. In other words, the annular groove 90d of the impact pin 90 always communicates with the first port 76A regardless of the position of the impact pin 90. Furthermore, the second port 76B always communicates with the clearance formed between the mid-diameter shaft portion 90b of the impact pin 90 and the small diameter bore portion 84b of the valve container bore 84.

[00053] When the projection length of the impact pin 90 is large, the second gasket 98b contacts the inner surface of the valve seat 86, and the third gasket

98c separates from the inner surface of valve seat 86 (see FIG. 6). Consequently, the first port 76A communicates with the third port 76C through the clearance between the inner surface of the valve seat 86 and the impact pin 90 including the annular groove 90d of the impact pin 90, and through the second through hole 86d and the annular recess 86b of the valve seat 86.

[00054] When the first drive piston 36 makes contact with the impact pin 90 and the projection length of the impact pin 90 becomes a little shorter than in the state described above, then both the second gasket 98b the third gasket 98c contacts the inner surface of the valve seat 86 (see FIG. 7). Consequently, the first port 76A does not communicate with either the second port 76B and the third port 76C.

[00055] When the projection length of the impact pin 90 is short, the second gasket 98b separates from the inner surface of the valve seat 86 and the third gasket 98c contacts the inner surface of the valve seat 86 (see FIG. 8) . Consequently, the first port 76A communicates with the second port 76B through the clearance between the inner surface of the valve seat 86 and the impact pin 90 including the annular groove 90d of the impact pin 90 and through the gap formed between the impact pin portion. medium diameter shaft 90b of impact pin 90 and small diameter bore portion 84b of valve container bore 84.

[00056] When pressurized fluid is supplied to the fourth port 76D, then the impact pin 90 is pushed in a direction that increases its projection length. This is because the area (pressure receiving area) in which the fluid pressure at the fourth port 76D acts in the direction of increasing the projection length of the impact pin 90 is larger than the area (pressure receiving area) at the which fluid pressure in the second port 76B acts in the direction to reduce the projection length of the impact pin 90.

[00057] On the other hand, when pressurized fluid is not supplied to the fourth port 76D, then the impact pin 90 is pressed in a direction that its projection length decreases. This is because the fluid pressure in the fourth port 76D acting in the direction to increase the projection length of the impact pin 90 disappears, while the fluid pressure in the second port 76B acting in the direction to reduce the projection length of the impact pin 90 is maintained.

[00058] The pressure intensifier 10 of the first embodiment of the present invention is configured basically as described above. Next, its operations, functions and effects will be described. As shown in FIG. 5, it is assumed that, in the initial position, the first operating valve 48 has switched to the second position, the second operating valve 52 has switched to the first position, and the intensifying piston 34 is positioned near the center in the intensifying chamber. 22. In the description below, in order to distinguish the first pilot valve impact pin 72 and the second pilot valve impact pin 74, the former will be referred to as "90-1 impact pin" and the latter will be referred to as " impact pin 90-2". Also, in order to distinguish the valve container hole of the first pilot valve 72 and the valve container hole of the second pilot valve 74, the former will be referred to as

"84-1 valve container hole" and the latter will be referred to as "84-2 valve container hole".

[00059] In this initial position, pressurized fluid is supplied from the pressurized fluid feed source to the feed port 40, and then the pressurized fluid flows to the first feed passage 42a and the second feed passage 42b . Then, pressurized fluid is introduced into the first intensifying chamber 22a and the second intensifying chamber 22b of the intensifying cylinder 12 through the first feed check valve 42c and the second feed check valve 42d.

[00060] Part of the pressurized fluid supplied from the supply port 40 is supplied to the pressurizing chamber 26a in the second actuating cylinder 16 through the passage 66c, the second operating valve 52 being in the first position, and the passage 66a. Pressurized fluid supplied to pressurizing chamber 26a drives second drive piston 38 in direction A1. Then, the intensifying piston 34, which is integrally coupled to the second actuating piston 38, slides to intensify the pressurized fluid pressure in the first intensifying chamber 22a of the intensifying cylinder.

12. The intensified pressurized fluid is guided through the first outlet passage 46a and the first outlet check valve 46c to the outlet port 44 and is sent therefrom.

[00061] On the other hand, the first drive piston 36, which is integrally coupled to the second drive piston 38, slides and then the volume of the pressurizing chamber 24a in the first drive cylinder 14 becomes small. Once the first operating valve 48 is in the second position, part of the pressurized fluid in pressurizing chamber 24a is collected in backpressure chamber 24b through passage 58a, passage 58e, and passage 58b, and the remainder of it is discharged through passage 58d.

[00062] As explained above, in the process in which the intensifying piston 34 moves from the initial position a certain distance in the direction A1, the first pilot valve 72 is in the first position and therefore the fluid is pressurized from the port of supply 40 is being supplied to the fourth port 80D of the second pilot valve 74 through the first pilot valve 72. On the other hand, the second pilot valve 74 is in the second position, and therefore pressurized fluid is not supplied to the fourth port 76D of the first pilot valve 72. Consequently, in the first pilot valve 72, the impact pin 90-1 is urged in the direction to reduce the projection length of the impact pin 90-1, and therefore the first pilot valve 72 is stably held in the first position. On the other hand, in the second pilot valve 74, the impact pin 90-2 is pushed in the direction to increase the projection length of the impact pin 90-2, and therefore the second pilot valve 74 is stably held in the second position. .

[00063] Then, as shown in FIG. 9, in the vicinity of the stroke end of the displacement of the intensifying piston 34 in the direction A1, the second actuating piston 38 contacts the impact pin 90-2 of the second pilot valve 74. The impact pin 90-2 is pushed and displaced by the second actuating piston 38, causing the first port 80A and the second port 80B of the second pilot valve 74 to communicate with each other. Thereafter, pressurized fluid from the supply port 40 is supplied to the pilot port 56F of the first operating valve 48 through the second pilot passage 82b, and also supplied to the fourth port 76D of the first pilot valve 72 through the branch passage 82c. This causes the first operating valve 48 to switch to the first position and the first pilot valve 72 to switch to the second position.

[00064] When the first pilot valve 72 has switched to the second position, pressurized fluid being supplied to the pilot port 64F of the second operating valve 52 flows through the first pilot passage 78b and is then discharged from the third port 76C of the first pilot valve 72. This causes the second operating valve 52 to switch to the second position.

[00065] Furthermore, when the first pilot valve 72 has switched to the second position, pressurized fluid that was being supplied to the fourth port 80D of the second pilot valve 74 is discharged from the third port 76C of the first pilot valve 72 through the branch passage 78c and the first pilot pass 78b. Consequently, in the second pilot valve 74, fluid pressure acts in the direction to reduce the projection length of the impact pin 90-2. Then, the impact pin 90-2, which has been pushed by the second actuating piston 38 and moved to a position in which the first port 80A and the second port 80B of the second pilot valve 74 communicate with each other, is further subjected to fluid pressure, and is maintained at the position where the impact pin 90-2 abuts the lower surface of the valve container bore 84-2. That is, the second pilot valve 74 is stably held in the first position. The state in which the second pilot valve 74 is held in the first position is maintained until the first drive piston 36 is driven in direction A2 and moves the impact pin 90-1, as will be described later.

[00066] This time, part of the pressurized fluid supplied from the supply port 40 is supplied to the pressurizing chamber 24a in the first actuation cylinder 14 through passage 58c, the first operating valve 48 being in the first position, and the passage 58a. Pressurized fluid supplied to pressurizing chamber 24a drives first drive piston 36 in direction A2. This causes the intensifying piston 34, which is integrally coupled to the first actuating piston 36, to slide to intensify the pressure of pressurized fluid in the second intensifying chamber 22b of the intensifying cylinder 12. The intensified pressurized fluid is guided through the second outlet passage 46b and from the second outlet check valve 46d to the outlet port 44 and is sent therefrom.

[00067] On the other hand, the second drive piston 38, which is integrally coupled to the first drive piston 36, slides, and then the volume of the pressurizing chamber 26a in the second drive cylinder 16 becomes small. Once the second operating valve 52 is in the second position, part of the pressurized fluid in pressurizing chamber 26a is collected in backpressure chamber 26b through passage 66a, passage 66e, and passage 66b, and the remainder of same is discharged through passage 66d.

[00068] Then, in the vicinity of the stroke end of the displacement of the intensifying piston 34 in the direction A2, the first actuating piston 36 contacts the impact pin 90-1 of the first pilot valve 72. The impact pin 90 -1 is pressed and displaced by the first actuating piston 36, causing the first port 76A and the second port 76B of the first pilot valve 72 to communicate with each other. Thereafter, pressurized fluid from supply port 40 is supplied to pilot port 64F of second operating valve 52 through first pilot passage 78b, and also supplied to fourth port 80D of second pilot valve 74 through branch passage 78c. This causes the second operating valve 52 to switch to the first position and the second pilot valve 74 to switch to the second position.

[00069] When the second pilot valve 74 has switched to the second position, pressurized fluid being supplied to the pilot port 56F of the first operating valve 48 is discharged from the third port 80C of the second pilot valve 74 through the second pilot passage 82b. This causes the first operating valve 48 to switch to the second position.

[00070] Furthermore, when the second pilot valve 74 has switched to the second position, pressurized fluid that was being supplied to the fourth port 76D of the first pilot valve 72 is discharged from the third port 80C of the second pilot valve 74 through the passage. branch 82c and second pilot pass 82b. Consequently, in the first pilot valve 72, fluid pressure acts in the direction to reduce the projection length of the impact pin 90-1. Then, the impact pin 90-1, which has been pushed by the first actuating piston 36 and moved to a position in which the first port 76A and the second port 76B of the first pilot valve 72 communicate with each other, is further subjected to fluid pressure, and is held in the position where the impact pin 90-1 abuts the lower surface of the valve container bore 84-1. That is, the first pilot valve 72 is stably held in the first position. The state in which the first pilot valve 72 is held in the first position is held until the second actuating piston 38 is actuated again in direction A1 and moves the impact pin 90-2. Thereafter, in the same way, the intensifying piston 34 repeats the reciprocal motion and the intensified pressurized fluid is continuously sent from the outlet port 44.

[00071] According to the pressure intensifier 10 of the modality, the impact pin 90-1 is pushed by the first actuating piston 36 and moved to a position so as to make the first port 76A and the second port 76B of the first pilot valve 72 communicate with each other, then the impact pin 90-1 is further pushed by a certain fluid pressure to a position where the impact pin 90-1 abuts the lower surface of the valve container bore 84-1 , and as a result, the impact pin 90-1 can be held in this position. In the same way,

after the impact pin 90-2 is pushed by the second actuating piston 38 and moved into a position so as to cause the first port 80A and the second port 80B of the second pilot valve 74 to communicate with each other, the impact pin 90-2 is further pushed by a certain fluid pressure to a position where the impact pin 90-2 abuts the lower surface of the valve container bore 84-2, and as a result, the impact pin 90-2 may be kept in this position.

[00072] In addition, the first operating valve 48 switches to the first position when pilot pressure is supplied from the second pilot valve 74 configured to switch its position in cooperation with the first pilot valve 72, and the first operating valve 48 switches to the second position when the pilot pressure supply from the second pilot valve 74 disappears. Likewise, the second operating valve 52 switches to the first position when pilot pressure is supplied from the first pilot valve 72 configured to switch its position in cooperation with the second pilot valve 74, and the second operating valve 52 switches to the second position when the pilot pressure supply from the first pilot valve 72 disappears. Thus, the first operating valve 48 and the second operating valve 52 operate stably and switch at the same time.

[00073] In addition, part of the fluid that was supplied to the pressurizing chamber 24a in order to drive the first actuating piston 36 is collected to the backpressure chamber 24b when the first actuating piston 36 is actuated in conjunction with the movement of the second actuating piston 38, and thus it is possible to reduce the consumption of the pressurized fluid. Likewise, part of the fluid that has been supplied to the pressurizing chamber 26a in order to drive the second actuating piston 38 is collected in the backpressure chamber 26b when the second actuating piston 38 is actuated in conjunction with the movement of the first actuating piston. drive 36, and thus it is possible to reduce the consumption of pressurized fluid.

[00074] The pressure intensifier according to the present invention is not limited to the modalities described above, but can, of course, adopt various configurations without departing from the essence and foundation of the present invention.

Claims (5)

1. Pressure intensifier in which actuating cylinders (14, 16) are respectively provided on both sides of an intensifying cylinder (12), the pressure intensifier characterized in that it comprises: a pair of pilot valves (72, 74) each including an impact pin (90) with which a piston (36, 38) of a corresponding one of the drive cylinders contacts a displacement end of the piston; and a pair of operating valves (48, 52), each configured to switch a supply state of a pressurized fluid from a pressurized fluid supply source to a pressurizing chamber (24a, 26a) of a corresponding one of the cylinders. actuation, in which, when one or the other of the pilot valves switches to a first position by the pilot valve impact pin being pushed by the corresponding piston, then a pressurized fluid supply state to the pair of operating valves is switched and a certain fluid pressure acts on the impact pin to keep the pilot valve in the first position. 2. Pressure intensifier according to claim 1, characterized in that a position of another of the operating valves is switched depending on the presence or absence of a pilot pressure supplied from one of the pilot valves, and a position of one of the operating valves is switched depending on the presence or absence of a pilot pressure supplied from another of the pilot valves. 3. Pressure intensifier according to claim 1, characterized in that one of the pilot valves has a supply port to which pressurized fluid is always supplied and a cooperation port to which pressurized fluid is supplied through one of the pilot valves, and the other one of the pilot valves has a supply port to which pressurized fluid is always supplied and a cooperating port to which pressurized fluid is supplied through one of the pilot valves, and in which, when pressurized fluid is supplied to the cooperating port of either pilot valve, then the pilot valve impact pin is urged in a direction in which the pilot valve moves towards a second position, and when the fluid pressurized is not supplied to the cooperating port, so a certain fluid pressure acts on the impact pin. 4. Pressure intensifier according to claim 3, characterized in that when one of the pilot valves is in the first position, a pilot pressure is supplied to the other of the operating valves and the pressurized fluid is supplied to the cooperation port of the other of the pilot valves, and when the other of the pilot valves is in the first position, pilot pressure is supplied to one of the operating valves and pressurized fluid is supplied to the cooperating port of one of the pilot valves. 5. Pressure intensifier according to claim 1, characterized in that each of the operating valves switches between a state in which the pressurized fluid is supplied to the pressurization chamber of a corresponding one of the drive cylinders and a pressurized fluid in a backpressure chamber (24b, 26b) of the drive cylinder is discharged, and a state in which part of the pressurized fluid in the pressurization chamber of the drive cylinder is collected in the backpressure chamber of the drive cylinder.