JPS6220401B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a self-acting amplifier used in the field of fluid equipment. (Tokuko Akira
This invention relates to an improvement of the "self-acting pressure intensifier" described in Japanese Patent Publication No. 59-26802).

Prior Art In a conventional pressure intensifier, a large diameter piston part and a small diameter rod part of a pressure intensifying piston are slidably fitted into a large diameter hole and a small diameter hole provided in the pressure intensifier body. A return side piston chamber is formed on the rod end side of the rod, and a feed side piston chamber is formed on the head end side of the rod, and a pressure intensifying chamber is formed on the rod end side of the rod part, with the feeding side piston chamber serving as an inflow port and the pressure increasing chamber serving as an outflow port. Since the configuration is such that the pressure intensifier is connected to each port in series, when only this pressure intensifier is connected in series in the middle of the cylinder's working fluid supply piping, the amount of working fluid in the cylinder is determined by the pressure intensifying piston. When the amount of extrusion of the working fluid is limited and the volume of the cylinder is large, the pressure intensifier must be extremely large, which poses the problem of greatly limiting the range of use. Therefore, in reality, a sequence and check valve is connected in series on the supply side of the working fluid supply piping connected to the pressure booster, and a bypass pipe is provided in parallel to the pressure booster and the sequence and check valve. A pilot check valve that opens when the pressure on the return side of the cylinder is higher is connected in the middle of this bypass piping, or a solenoid valve is connected in series in the middle of the supply side of the working fluid supply piping connected to the pressure intensifier. A bypass pipe is provided in parallel to the solenoid valve, a pilot check valve is connected in the middle of this bypass pipe, and a pressure switch is provided that detects the pressure on the sending side of the cylinder and operates the solenoid valve. Therefore, the pressure intensifier is not operated while the main piston of the cylinder is moving, but is operated after the main piston of the cylinder has stopped. However, when using the pressure booster described above, it is necessary to connect various devices and piping in addition to the pressure booster connection, which makes assembly extremely troublesome and difficult to install in a narrow space. In addition, the number of parts required for the entire pressure booster increases, making handling complicated and increasing the overall price, which limits the range of applications for pressure boosters, both directly and indirectly. It was hot.

Therefore, in order to solve the above-mentioned problems, the applicant of the present application filed Japanese Patent Application Laid-open No. 53-21376 (Japanese Patent Publication No. 59-21376) prior to the earlier application.
-26802), by simply connecting the cylinder in series in the middle of the working fluid supply piping and supplying the working fluid to this working fluid supply piping, it is necessary to move the main piston of the cylinder. The required amount of working fluid can be supplied, and the pressure can be increased automatically after the main piston stops moving, and the supply of working fluid to the working fluid supply piping can be simply switched to discharge. We have developed a self-acting pressure booster that can discharge as much working fluid as necessary from the feed side of the cylinder.

Problems to be solved by the invention Regarding the self-acting pressure booster developed above,
Since the pressure booster piston is returned by a return spring or pressure oil, if the former return spring is used, the pressure increase force of the pressure booster piston is reduced by an amount corresponding to the spring force of the return spring. Failures are likely to occur due to the return spring, and when using the latter method, such as pressure oil, it is necessary to detect the sliding end of the pressure booster piston and switch the flow of pressure oil each time, which complicates the attached equipment. There was a problem.

Means for Solving the Problems Therefore, the present invention solves the above problems, and by simply incorporating it directly into a fluid supply circuit for pressurizing equipment, etc., it normally functions as a mere supply passage without performing a pressure increase action. When the pressurizing equipment enters the pressurized state, it can automatically increase the pressure, and the pressure of the supplied fluid can be reduced by changing the primary pressure of the supplied fluid. The aim is to provide a self-acting pressure intensifier that is extremely easy to install and operate, and can automatically repeat the pressure increase action continuously each time the pressure is increased. A pressure booster piston having a large diameter part and a small diameter part is slidably fitted into the cylinder body, thereby forming large diameter front and rear piston chambers and a small diameter secondary pressure chamber in the cylinder body. The cylinder body is provided with a supply port for supplying pressurized fluid, a drain port that communicates with the front piston chamber, and a discharge port that communicates with the secondary pressure chamber, and the pressure booster piston has a supply port that is connected to the supply port at all times. A communicating primary pressure chamber is provided, and a first communicating passage for communicating the primary pressure chamber with the secondary pressure chamber, a second communicating passage for communicating the primary pressure chamber with the rear piston chamber, and a rear side. A third communicating passage is provided for communicating the piston chamber with the front piston chamber, and the first communicating passage includes a valve seat and a secondary pressure chamber side of the valve seat that is biased to press against the valve seat. a check valve consisting of a valve body which is in pressure contact with the valve seat; A return valve consisting of a valve seat and a valve body whose position is regulated by being biased away from the valve seat on the piston chamber side in front of the valve seat is interposed in the third communication passage. The valve bodies of the valve, the pressure booster valve, and the return valve are disposed on the same axis so as to move in the same direction as the sliding axis of the pressure booster piston, and at least the valve body of the return valve is in the primary pressure chamber. A movable body is provided which moves integrally with the valve body during the movement stroke until it comes into pressure contact with the valve seat of the return valve, and the movable body normally moves the valve body of the check valve away from the valve seat against the urging force. A push-up protrusion is provided to separate the valve body, and the biasing force of the valve body of the pressure increase valve is such that the valve body of the return valve is moved backward by the primary pressure of the pressurized fluid in the primary pressure chamber, and the return valve and the check valve are closed. After the pressure increase valve is set to a size such that it is opened by pressurized fluid, and when the primary pressure becomes higher than the set pressure, the check valve and the return valve are closed by the backward movement of the valve body of the return valve. The pressure increase valve is opened by pressure fluid, and when the primary pressure becomes lower than the set pressure, the pressure increase valve is closed by force, and then the check valve and the return valve are opened by force. It is characterized by

Function When the discharge port is connected to a pressurizing device, the supply port is connected to a pressurized fluid source, and the drain port is connected to a drain receiver to supply pressurized fluid to the primary pressure chamber, this pressurized fluid will be released when its pressure is below a specified pressure. It is supplied to pressurized equipment through a check valve. When this pressurizing device is pressurized and the pressure in the primary pressure chamber exceeds a predetermined pressure, the pressurized fluid moves the valve body of the return valve backward against the urging force, causing the valve body to move backward against the biasing force. At the same time, the movable body moves backward to release the pushing up of the check valve valve body by the push-up protrusion, and as a result, the check valve valve body presses against the valve seat and closes the check valve. will be closed. Thereafter, the pressure fluid in the primary pressure chamber pushes up the valve body of the pressure increase valve against the urging force to open the pressure increase valve. As a result, the pressurized fluid in the primary pressure chamber flows into the rear piston chamber, and the pressure increasing piston is slid forward to increase the pressure of the pressurized fluid in the secondary pressure chamber.
In addition, when the pressure in the primary pressure chamber becomes lower than the predetermined pressure,
The valve element of the pressure increase valve is pressed against the valve seat by the force to close the pressure increase valve, and then the valve element of the return valve is moved forward by the force to open the return valve. Therefore, the pressure fluid in the rear piston chamber flows to the front piston chamber and is discharged from the drain port, and the pressure fluid in the primary pressure chamber flows into the secondary pressure chamber, causing the pressure booster piston to slide rearward and return. .

Embodiments Hereinafter, drawings showing embodiments of the present invention will be described in detail.

Incidentally, in the drawings of the embodiments, some parts of the drawings ignore assembly and manufacturing relationships for the sake of explanation, but it goes without saying that these parts can be changed as necessary.

Figures 1, 2, and 3 show a first embodiment implemented as a general-purpose type that can be widely applied. Reference numeral 1 denotes a cylinder body, which is composed of a cylinder tube 2, a head end cap 3 and a rod end cap 4 fixed to the ends of the cylinder tube 2. This cylinder body 1 has a large diameter hole 1a and a small diameter hole 1b arranged in a stepped manner, and the ratio of the diameters of the large diameter hole 1a and the small diameter hole 1b is set to an appropriate size depending on the desired pressure increase ratio. is set to . 5 is a hollow pressure increasing piston consisting of a large diameter part 5a and a small diameter part 5b;
and a small diameter hole 5b are slidably fitted into the large diameter hole 1a and the small diameter hole 1b of the cylinder body 1, respectively, so that a large diameter front piston chamber 6 is formed in the cylinder body 1.
A rear piston chamber 7 and a small diameter secondary pressure chamber 8 are defined. Reference numeral 9 denotes a central tube provided in the head end cap 3, which protrudes into the cylinder body 1 with the same axis line, and is provided with a considerable clearance between the large diameter hole 10 and the small diameter hole 11 formed in the pressure booster piston 5. It's coming. The bore of the central tube 9 constitutes a fluid passage 13 communicating with a supply port 12 provided in the head end cap 3. Reference numeral 14 denotes a discharge port provided in the rod end cap 4, which communicates with the secondary pressure chamber 8. A drain port 15 is provided in the cylinder tube 2 and communicates with the front piston chamber 6. Next, reference numeral 16 denotes a primary pressure chamber 16 formed in the small diameter hole 11 of the pressure boosting piston 5. The distal end of the central tube 9 is inserted into the primary pressure chamber 16, and the fluid passage 13 is opened. Reference numeral 17 designates a valve body storage chamber formed at the tip of the small diameter portion 5b of the pressure boosting piston 5, which is open into the secondary pressure chamber 8 and is connected to the primary pressure chamber 16.
A part of it is partitioned by a painting wall 18, and this painting wall 1
A valve hole 19 provided in the center of the primary pressure chamber 16
is communicated with. This valve hole 19 and the valve body storage chamber 1
7 constitutes a first continuous passage A for communicating the primary pressure chamber 16 with the secondary pressure chamber 8. Reference numeral 20 denotes a presser metal fitting fixed to the rear part of the large diameter hole 10 of the pressure booster piston 5, which has a sliding hole 21 in the center with a diameter larger than the diameter of the central tube 9, and the inside of this sliding hole 21 is inserted into the central tube. 9 penetrates with plenty of room. 22 is large diameter hole 1
It is a hollow chamber formed within 0. 23 is small diameter hole 1
A stopper stepped portion formed in the middle of the valve 1 engages with an engaging flange of a second valve body, which will be described later, to prevent the second valve body from moving to the right. Although this stopper step portion 23 is formed by having different hole diameters, it may also be formed by a cutout groove or a protrusion.
Reference numeral 24 denotes a sliding hole formed in a part of the head end side of the small diameter hole 11 so as to communicate with the primary pressure chamber 16 and the hollow chamber 22. This sliding hole 24, the hollow chamber 22, and the sliding hole 21 constitute a second communication path B for communicating the primary pressure chamber 16 with the rear piston chamber 7. Reference numeral 26 denotes a communication hole provided in the large diameter portion 5a of the pressure boosting piston 5, which allows the hollow chamber 22 and the front piston chamber 6 to communicate with each other. This communication hole 26, the hollow chamber 22, and the sliding hole 21 are connected to the rear piston chamber 7.
A third communication passage C is configured to communicate the front piston chamber 6 with the front piston chamber 6.

Next, 25 is the valve body storage chamber 17 of the first communication path A.
A check valve body of the check valve 28 is a check valve body fitted inside the check valve 28 so as to be slidable in the left-right direction, and the right end thereof is provided with a tapered valve portion 25a and a communication hole 25b. This check valve body 25 is a receiver 27a.
The valve portion 25a is pressed to the right by a spring 27 compressed and sealed between the check valve 28 and the fixed valve seat 18a of the partition wall 18, which constitutes the valve seat of the check valve 28. Valve part 25a and fixed valve seat 1
8a constitutes a check valve 28 that reverses the flow of fluid from the secondary pressure chamber 8 to the primary pressure chamber 16 side. Reference numeral 29 denotes a snap spring that prevents the receiver 26 from being removed. A first valve body 30 is housed in the hollow chamber 22 of the pressure increase piston 5, and constitutes the valve body of the pressure increase valve 46 and the return valve 53.
0a is provided with sliding parts 30b and 30c having the same axes at both ends, and these sliding parts 30b,
30c is fitted in a sliding hole 24 of the pressure boosting piston 5 and a sliding hole of a movable valve seat body, which will be described later, in an airtight manner. The first valve body 30 has a valve hole 31 having a larger diameter than the center pipe 9 in its center over its entire length, and forms an annular communication path 32 with the center pipe 9. Further, a valve portion 33 is formed at the front end (left end in FIG. 1) of the first valve body 30, and a tapered valve portion 34 is formed at the rear end. Furthermore, the flange 30a of the first valve body 30 has a through hole 35, into which a stopper pin 36 is fitted. 37 is the flange portion 30a of the first valve body 30
The collar portion 30a is pressed against the front end surface of the hollow chamber 22 of the pressure intensifying piston 5 by a spring having a predetermined elastic force that is compressed and sealed between the presser fitting 20 and the presser fitting 20.
A second valve body 38 is a cap-shaped movable body housed in the primary pressure chamber 16 of the pressure booster piston 5, and has a sliding hole 38a that opens at the rear end surface, and the sliding hole 38a is hollow. It is slidably fitted to the outer periphery of the tip of the tube 9 in an airtight manner. This second valve body 38 has a communication hole 39 in its front end portion that communicates the inside and outside,
The primary pressure chamber 16 is constantly communicated with the supply port 12 via the sliding hole 38a and the fluid passage 13. Further, at the front end of the second valve body 38, there is a push-up protrusion 40 for opening the check valve 28 that faces inside the valve hole 19, and on the outer periphery there is an engagement flange 41 that can be engaged with the stopper step 23.
However, a tapered valve seat 42 that can come into contact with the valve portion 33 is formed at the rear end. Moreover, between this second valve body 38 and the small diameter hole 11, the second valve body 38 is made smaller in diameter than the small diameter hole 1b, and the second valve body 3
A notch groove 43 is provided on the outer periphery of the second valve body 8 to form a communication passage 44 that communicates the front and rear sides of the second valve body 38. Note that this communication passage 44 may be formed by providing a long groove in the second valve body 38. Reference numeral 45 denotes a spring with a weak elastic force compressed and sealed between the engagement flange 41 of the second valve body 38 and the front end surface of the small diameter hole 11, which urges the second valve body 38 rearward and pushes the valve seat 42. The pressure increase valve 46 is brought into pressure contact with the valve seat 33 of the first valve body 30 described above, and the valve portion 42 and the valve portion 33 constitute a pressure increase valve 46 that reverses the flow from the primary pressure chamber 16 to the rear piston chamber 7. In the state where the valve seat 42 is in pressure contact with the valve portion 33 of the first valve body 30 that is in contact with the front end surface of the hollow chamber 22 as described above,
Engagement collar 41 of second valve body 38 and stopper stepped portion 23
There is a margin of stroke L2 between the two, and the push-up protrusion 40 pushes back the check valve body 25 by a stroke L1, which is smaller than this stroke L2.
The dimensional relationship is set so that the check valve 28 is opened. 47 is the hollow chamber 22 of the pressure boosting piston 5
It is a movable valve seat body housed inside, and has a sliding part 47a and a flange part 47b, and this sliding part 47a is attached to the presser fitting 20.
is slidably fitted in a sliding hole 21 in an airtight manner. This movable valve seat body 47 has a valve hole 48 with a larger diameter than the central pipe 9 in the center of the sliding part 47a, and a communication passage that communicates the front and rear of the sliding part 47a with the central pipe 9. 49 is formed. Further, the flange portion 47b has a sliding hole 50 that is continuous with the communication path 49, and the sliding portion 30c of the first valve body 30 is fitted into the sliding hole 50 so as to be able to slide in an airtight manner. Furthermore, the flange portion 47d has a communication hole 51 that communicates the communication passage 49 with the hollow chamber 22, and a valve seat that can come into contact with the valve portion 34 is provided in the middle between the communication hole 51 and the communication passage 49. 52 is formed. This valve seat 52 constitutes a return valve 53 together with the valve portion 34 of the first valve body 30. The diameter of the valve seat 52 of this return valve 53 is set smaller than the diameter of the sliding hole 24 and the sliding hole 21, and the second
The first valve body 30 and the movable valve seat body 4 in the pressure increasing state shown in the figure.
7 so that they do not separate. Reference numeral 54 denotes a spring with a weak elastic force compressed and sealed between the flange 47b of the movable valve seat body 47 and the presser fitting 20, which urges the movable valve seat body 47 forward to release the stopper pin 36.
It is in contact with the In this case, the return valve 53 closes before the pressure increase valve 46 opens, and is opened by a stroke L3 smaller than the stroke L2 so that it opens after the pressure increase valve 46 closes. In addition, the first valve body 3
There is a gap L4 larger than the stroke L3 between the flange 30a of 0 and the flange 47b of the movable valve seat body 47 so that the valve part 34 and the valve seat 52 can come into contact with each other. A distance L5 is provided between the portion 47b and the presser metal fitting 20, which is larger than the difference between the stroke L3 and the stroke L2.

Next, the operation will be described in the case where the pressure intensifier as described above is installed in series in, for example, a pressure oil supply line to a press-in device.

First, when pressurized oil is supplied from the supply port 12 in order to operate the press-fitting device in the state shown in FIG. 19 and the communication hole 25b of the check valve body 25, it enters the secondary pressure chamber 8, flows out from the outflow port 14, and slides the press-fit piston of the press-fit device. In this case, primary pressure chamber 1
Since the pressure oil flowing through the chamber 6 only slides the unloaded press-fit piston, the primary pressure of the pressure oil inside the primary pressure chamber 16 will not rise above the predetermined set pressure P, and the above-mentioned The pressure increase valve 46 is maintained in a closed state as shown in FIG. Thereafter, the press-fitting piston of the press-fitting device comes into contact with the object to be press-fitted, and when a load is applied to the press-fitting piston, the primary pressure of the pressure oil in the primary pressure chamber 16 increases. When the primary pressure of the pressure oil in the primary pressure chamber 16 rises above the set pressure P, this primary pressure is applied directly to the left pressure receiving surface of the first valve body 30 or indirectly through the second valve body 38. The first valve body 30 is caused to slide to the right against the elastic force of the spring 37. When the first valve body 30 slides to the right in this manner, the second valve body 38 also slides to the right together with it, and as a result, the pressing protrusion 40 first releases the push-up of the check valve body 25. Therefore, the check valve body 25 is slid to the right by the elastic force of the spring 27, and the valve portion 25a is brought into airtight pressure contact with the valve seat 18a, and the valve hole 19 is brought into contact with the valve seat 18a.
is closed, and the check valve 28 restores its check function. Further, when the first valve body 30 is slid rearward as described above, the valve portion 34 engages with the valve seat 52 to close the return valve 53, and the first valve body 30 is then moved to the movable valve seat body. 47 are slid together toward the rear against the spring 54. The closing of the return valve 53 by the first valve body 30 may be earlier or later than the closing of the check valve 28. By closing the return valve 53, communication between the rear piston chamber 7 and the hollow chamber 22 is closed. After that, when the first valve body 30 and the second valve body 38 are further slid rearward, the engagement flange 41 of the second valve body 38 engages with the stopper step 23, and the second valve body 38 After the sliding is stopped, the first valve body 3
0 slides backward, the valve portion 33 is separated from the valve seat 42, and the pressure increase valve 46 is opened. Therefore, the pressure oil supplied into the primary pressure chamber 16 is supplied to the communication passage 44 formed on the outer periphery of the second valve body 38, the communication passage 32 formed within the first valve body 30, and the communication passage formed within the movable valve seat body 47. It flows into the rear piston chamber 7 through the communication passage 49. Further, even after the first valve body 30 is separated from the second valve body 38, it is further slid backward due to the difference in pressure receiving area between the sliding portion 30b and the sliding portion 47a of the movable valve seat body 47, and the movable body seat The flange 47b of the body 47 is the presser metal fitting 2
0 and its position is regulated. In this case, since the diameter of the valve seat 52 of the movable valve seat body 47 is smaller than the diameter of the sliding portion 47a, the return valve 53 is reliably kept closed. When the check valve 28 recovers its non-return function as described above and pressure oil at the primary pressure flows into the rear piston chamber 7, the primary pressure of this pressure oil is transferred to the pressure booster piston 5.
It acts on the large diameter part 5a of the large diameter part 5a and the small diameter part 5b.
Pressure oil in the secondary pressure chamber 8 is increased at a pressure ratio determined by the ratio of the cross-sectional areas. The increased secondary pressure of the pressurized oil in the secondary pressure chamber 8 acts on the press-fitting piston of the press-fitting device, and the pressure-increasing piston 5 slides forward to perform a predetermined press-fitting operation. When the work is completed, the pressure increasing piston 5 stops sliding as shown in FIG. 2, and this state is maintained. In addition, when the gripping piston does not slide any further after gripping the workpiece, such as in a clamping device, the pressure increase piston 5 does not slide much as in the above embodiment, and returns to its original position. The pressure oil in the secondary pressure chamber 8 is increased in pressure. When the pressure booster piston 5 increases the pressure of the pressure oil in the secondary pressure chamber 8 as described above, the primary pressure of the pressure oil flowing into the rear piston chamber 7 is the maximum supply pressure supplied to the inflow port 12 by a pump or the like. Under this maximum supply pressure, the pressure of the pressure oil in the secondary pressure chamber 8 is increased.

After performing the press-fitting work as described above, in order to retreat the press-fit piston, the supply of pressure oil to the supply port 12 is switched to discharge to release the primary pressure, and the primary pressure drops below the set pressure P. First, the first valve body 30 and the movable valve seat body 47 are slid forward by the elastic force of the springs 37 and 54 with the return valve 53 closed.
3 engages with the valve seat 42 of the second valve body 38 and the pressure increase valve 4
6 is closed, and then the first valve body 30 closes the second valve body 3.
Press 8 and slide it forward. As a result, the push-up protrusion 40 of the second valve body 38 pushes up the check valve body 25 against the spring 27, thereby opening the check valve 28. Therefore, the pressure oil in the secondary pressure chamber 8 is supplied to the supply port 1.
2, allowing the press-fit piston to return. On the other hand, when the first valve body 30 and the movable valve seat body 47 are slid forward as described above, the sliding movement of the movable valve seat body 47 is stopped by the stopper pin 36 after the pressure increase valve 46 is closed as described above. Then, the return valve 53 is opened by sliding the first valve body 30 forward, and then the first valve body 30 is inserted into the inner surface of the hollow chamber 22 of the pressure boosting piston 5 as shown in FIG. It makes contact and returns to its original position. The return valve 53 may be opened before or after the check valve 28 is opened. When the return valve 53 is opened with the pressure increase valve 46 closed as described above, the pressure of the pressure oil in the rear piston chamber 7 is released, and this rear piston chamber 7
The oil inside flows out from the drain port 15. In this case, even when the oil in the primary pressure chamber 16 and the secondary pressure chamber 8 is discharged from the supply port 12, there is still considerable residual pressure, so the pressure boosting piston 5 is moved backward by this residual pressure. It will automatically slide back into the state shown in Figure 1. Therefore, the next press-fitting operation can be carried out immediately by supplying pressure oil to the supply port 12 again. In order to reduce the primary pressure below the set pressure, instead of switching the supply of pressure oil to the supply port 12 to discharge, a bypass circuit equipped with a relief valve or the like may be opened.

In the above operation, if the amount of oil required for press-fitting is greater than the amount of pressure applied by the pressure booster piston 5, the pressure booster piston 5 slides to the stroke end on the rod end side while increasing the pressure and then stops. When the supply of pressure oil is temporarily stopped, the pressure increasing piston 5 automatically returns to its original position as described above, and the pressure can be increased again. That is, by intermittent supply of pressure oil to the supply port 12, the press-fit piston can be slid in a large amount in a press-fit state.

Furthermore, when the pressure intensifier configured as described above is used to increase the pressure in a punching press, etc., the punching press completes punching while the pressure intensifier piston is performing the pressure increasing action, and the pressure in the secondary pressure chamber 8 is increased. When the secondary pressure of the pressure oil decreases, the pressure booster piston 5 slides toward the rod end and the primary pressure decreases, and when the pressure falls below a predetermined set pressure, the check valve 28 is opened as described above and the primary pressure chamber 16 is The pressure oil inside flows into the secondary pressure chamber 8 again, and the pressure boosting piston 5 is automatically returned to its original position. In this case, even if the pressure of the supplied fluid does not fall below the predetermined set pressure, the check valve body 25 is pushed up by the pressure oil in the primary pressure chamber 16 after the pressure booster piston 5 has slid to the stroke end on the rod end side. , whereby the primary pressure is reduced below a predetermined set pressure and the operation is performed as described above.

Next, FIG. 4 shows a second embodiment of the present application, in which pressure oil is supplied to the primary pressure chamber 16e from the head end side of the cylinder body 1 using the center pipe 9 as in the first embodiment. Instead, this is done from the side of the cylinder tube 2e. That is, 12e is a supply port provided in the cylinder tube 2e, 9e is an annular space provided on the inner surface of the small diameter hole 16a of the cylinder body 1e in correspondence with this supply port 12e, and 55 is a connection between this annular space 9e and the primary pressure chamber 1.
6e, the supply port 12e and the primary pressure chamber 16e are always in communication via the annular space 9e and the communication hole 55 even when the pressure booster piston 5e slides. It is becoming more and more maintained. As described above, the pressure increasing operation can be performed in substantially the same manner as in the first embodiment. This embodiment has the advantage that it can be manufactured more easily because no central pipe is used, and that the pressure oil supply piping can be provided from the side of the cylinder body 1e. It should be noted that portions that are considered to have the same or equivalent configuration as those of the first embodiment are given the same reference numerals with an alphanumeric letter "e" and redundant explanation will be omitted. Similarly, in FIG. 5 shown below, elements that are considered to have the same or equivalent configuration as those in the previous figure are given the letter f, and redundant explanation will be omitted.

FIG. 5 shows a third embodiment of the present application, in which the structures of the second communication passage Bf, the third communication passage Cf, the pressure increase valve 46f, and the return valve 53f are changed. 56 is a cylindrical valve seat body fitted and fixed in the large diameter hole 10f of the pressure booster piston 5f, and the central hole has a first valve chamber 57, a valve hole 58, a second valve chamber 59, and a sliding valve in order from the front end side. Moving hole 6
A first valve seat 52f and a second valve seat 33 are formed on both edges of the valve hole 58, respectively.
f is formed. 62 is a stop for the valve seat body 56. Reference numeral 20f denotes a presser fitting that fits into the rear end of the storage hole 61 and is prevented from coming out with a stopper 63, and has a sliding hole 21f in the center, and this sliding hole 21f is connected to the hollow tube 9.
f in a hermetically slidable manner. Reference numeral 64 denotes an annular communication chamber formed between the outer periphery of the valve seat body 56 and the inner periphery of the large diameter hole 10f, which communicates with the rear piston chamber 7f through the communication hole 65, and which communicates with the inside of the valve hole 58 through the communication hole 66. is communicated with. This communication hole 6
5. The communication chamber 64, the communication hole 66, the valve hole 58, the first valve chamber 57, and the communication hole 26f constitute a third communication path Cf. 38f is a second valve body as a movable body in which the sliding hole 38af is slidably fitted in the hollow tube 9f in an airtight manner, and the sliding part 67 formed on a part of the outer periphery constitutes the return valve 53f. Sliding hole 2 in the pressure booster piston 5f
4f, and is slidably fitted in an airtight manner. This second valve body 38f is formed with a tapered valve portion 34f that can engage with the first valve seat 52f, and this valve portion 34f and the first valve seat 52f constitute a return valve 53f. Further, the hollow chamber 68 of the second valve body 38f is communicated with the second valve chamber 59 through a communication hole 69. This communication hole 69, the second valve chamber 59, the valve hole 5
8, the communication hole 66, the communication chamber 64, the communication hole 65, the hollow chamber 68, and the communication hole 39f constitute a second communication path Bf. A biasing member 70 is fixed to the rear end of the second valve body 38f, and is slidably fitted into the hollow tube 9f. This biasing member 70 is biased forward by a disc spring 71 compressed and sealed between it and the presser fitting 20f, so that the sliding portion 67 of the second valve body 38f is pressed against the stopper 72 of the pressure increase piston 5f. There is. In this case, the return valve 53f has a stroke L
Only a stroke L3f larger than 1f is opened. 30f is a first valve body that is slidably fitted in the sliding hole 60 of the valve seat body 56 in an airtight manner;
It is slidably fitted in an airtight manner to the outer periphery of 8f.
This first valve body 30f has a communication hole 7 that constantly communicates the communication hole 69 of the second valve body 38f with the second valve body 59.
It has 3. Further, the front end of the first valve body 30f has a tapered valve portion 42 that engages with the second valve seat 38f.
f is formed, and this valve part 42f and the second valve seat 33f
and constitute a pressure increase valve 46f. The first valve body 30f is biased forward by the leaf spring 74, thereby closing the pressure increase valve 46f.

Since the present embodiment is configured as described above, when the primary pressure in the primary pressure chamber 16f becomes equal to or higher than the predetermined set pressure P1, the second valve body 38f is slid rearward against the disc spring 71. As a result, the check valve body 25f
The push-up by the push-up projection 40f is released and the check valve 28f is closed. After that, the second valve body 3
The valve portion 34f of 8f engages with the first valve seat 52f to close the return valve 53f, and at the same time, rearward sliding of the second valve body 38f is stopped. Thereafter, when the primary pressure of the pressure oil flowing into the second valve chamber 59 becomes equal to or higher than the set pressure P2, the first valve body 30f slides backward against the leaf spring 74, thereby opening the pressure increase valve 46f. Ru. Therefore, the pressure oil supplied into the primary pressure chamber 16f flows into the rear piston chamber 7f to perform a pressure increasing action. Next, when the primary pressure in the primary pressure chamber 16f drops below the set pressure P2, the first valve element 30f returns to its original position by the leaf spring 74 and closes the pressure increase valve 46f, and when the primary pressure further drops below the set pressure P1, The second valve body 38f is returned by the disk spring 71 and the return valve 53
f is opened, and check valve 28f is also opened. Therefore, the oil in the secondary pressure chamber 8f is supplied to the supply port 1.
It becomes possible to flow from 2f, and the pressure increase piston 5f
is automatically slid back to the rear.

Note that the present application is not limited to the above embodiment, and the first, second, and third passages are formed independently, and the check valve, pressure increase valve, and return valve provided in these passages are It goes without saying that the design may be changed as appropriate so that it opens and closes in a predetermined relationship depending on the magnitude of the pressure. Alternatively, the pressure intensifier may be connected to a fluid-operated device and the discharge port may be replaced by a small diameter hole in the cylinder body. In this way, the pressure intensifier itself can be attached to a gripping arm of a robot or a workpiece in a machine tool, for example. Can be used as a presser arm. In addition, the entire device is compact and convenient to handle.

As described above, in the present invention, when the primary pressure of the supplied fluid is lower than the set pressure, the fluid supplied to the supply port is directly discharged from the discharge port, and when the primary pressure becomes higher than the set pressure, the pressure is automatically increased. Since the pressure booster oil is discharged when the action starts, there is no need to separately install a special booster circuit, switching device, pressure detection device, etc., and it can be connected directly in series to the normal fluid supply piping of fluid-operated equipment. Pressure can be increased just by connecting, which simplifies assembly work and reduces the time and labor required for assembly, making it economical. In addition, as mentioned above, since there is no need to attach any other attachments for pressure increase, the whole can be made extremely compact during manufacture, allowing for expansion of the range of use and convenient handling. effective. Furthermore, even if the pressure booster piston automatically starts pressure boosting action and moves forward when the primary pressure of the supply fluid becomes higher than the set pressure as described above, the pressure booster will not increase when the primary pressure becomes lower than the set pressure. After the pressure valve is closed, the check valve and return valve are opened, and the pressure booster piston is automatically moved backward by this primary pressure and returned to its original position. Pressurized oil can be repeatedly discharged without installing a separate return circuit, making it easy to operate. Moreover, since the pressure increase piston does not receive any resistance from the return spring etc. during pressure increase,
It has the characteristics of being able to perform an effective pressure increase action and to maintain a constant secondary pressure at all times.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the present invention, FIGS. 2 and 3 are sectional views showing the operating state of FIG. 1,
FIG. 4 is a sectional view showing the second embodiment, and FIG. 5 is a sectional view showing the third embodiment.
It is a sectional view showing an example. 1...Cylinder body, 1a...Large diameter hole, 1b...
...Small diameter hole, 5...Pressure booster piston, 5a...Large diameter part, 5b...Small diameter part, 6...Front side piston chamber, 7
... Rear piston chamber, 8 ... Secondary pressure chamber, 12 ...
Supply port, 14...Discharge port, 15...Drain port, 16...Primary pressure chamber, A...First communication passage, B...Second communication passage, C...Third communication passage, 28
... Check valve, 46 ... Pressure increase valve, 53 ... Return valve.

Claims (1)

[Claims] 1 A large diameter hole and a small diameter hole are continuously provided in the cylinder body, and the large diameter part and the small diameter part of the pressure booster piston, which has a large diameter part and a small diameter part, can freely slide in these large diameter holes and small diameter holes, respectively. The cylinder body has a supply port for supplying pressurized fluid, and a large-diameter front and rear piston chambers are formed in the large-diameter hole, and a small-diameter secondary pressure chamber is formed in the small-diameter hole. A drain port that communicates with the front piston chamber and a discharge port that communicates with the secondary pressure chamber are provided, and the pressure booster piston is provided with a primary pressure chamber that constantly communicates with the supply port. A first communication passage for communicating with the secondary pressure chamber, a second communication passage for communicating the primary pressure chamber with the rear piston chamber, and a third communication passage for communicating the rear piston chamber with the front piston chamber. A check valve consisting of a valve seat and a valve body which is urged to come into pressure contact with the valve seat on the side of the secondary pressure chamber of the valve seat is interposed in the first communication passage, and A pressure increase valve consisting of a valve seat and a valve body urged to come into pressure contact with the valve seat is interposed in the second communication passage, and a pressure increase valve consisting of a valve seat and a piston in front of the valve seat is disposed in the third communication passage. A return valve consisting of a valve body whose position is regulated by being biased away from the valve seat is provided on the chamber side, and the valve bodies of the check valve, pressure increase valve, and return valve are on the same axis. is arranged so as to move in the same direction as the sliding axis of the pressure booster piston, and the valve is disposed in the primary pressure chamber at least during the movement stroke until the valve body of the return valve comes into pressure contact with the valve seat of the return valve. a movable body that moves integrally with the pressure booster valve; the movable body is provided with a push-up protrusion that normally moves the valve body of the check valve away from the valve seat against the urging force; The biasing force is such that the valve body of the return valve is moved backward by the primary pressure of the pressure fluid in the primary pressure chamber, the return valve and the check valve are closed, and then the pressure booster valve is opened by the pressure fluid. A self-acting pressure booster characterized by: