JP2003322111A - Fluid pressure cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply pressure on an object with high accuracy via a piston rod driven by fluid pressure. <P>SOLUTION: A piston 15 is incorporated in a cylinder body 12 reciprocatingly and a piston rod 11 is supported to the piston 15 reciprocatingly. The leading end of the piston rod 11 projects outwardly from the cylinder body 12. The piston 15 and a diaphragm 33 for pressurizing define a pressurizing chamber 42, and the piston 15, the piston rod 11, a diaphragm 31 for balancing, and a diaphragm 32 for blocking define a balancing pressure chamber 34. The piston rod 11 is pressed in an advancing direction by supplying fluid pressure P3 to the chamber 42 in a state that thrust in a retreat direction is generated in the piston rod 11 by supplying fluid pressure P4 to the chamber 34, and gravity applied on the piston rod 11 is offset. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure cylinder which linearly reciprocates a piston rod by fluid pressure such as compressed air.

[0002]

2. Description of the Related Art A fluid pressure cylinder that converts fluid energy such as compressed air into linear movement of a piston rod has a cylinder tube in which a piston is mounted so as to be reciprocally movable in an axial direction. End covers are provided at both ends of the cylinder tube, and the cylinder body is formed by the cylinder tube and the end covers. A piston rod is attached to the piston so as to project from the end of the cylinder body. By supplying fluid pressure to a pressure chamber formed in the cylinder body, the piston and the piston rod are integrally driven in the axial direction. .

The fluid pressure cylinders are classified into a double-acting type and a single-acting type due to structural differences. The double-acting fluid pressure cylinder has pressure chambers formed on both sides of the piston.
While the piston rod is a type of cylinder that performs forward movement and backward movement by fluid pressure, a single-acting fluid pressure cylinder has a pressure chamber only on one side of the piston, and either the forward movement or the backward movement is performed. It is a type of cylinder that performs fluid pressure while performing the other with external force such as spring force. A type in which the piston rod projects from one end of the cylinder body is called a single rod, and a type in which the piston rod projects from both ends is called a double rod. Compressed air may be used as fluid energy for driving the piston, and liquid such as hydraulic oil may be used.

In any type of fluid pressure cylinder, conventionally, the piston rod is fixed to the piston, and the piston rod linearly reciprocates integrally with the piston. Since the piston moves while contacting the inner peripheral surface of the cylinder body, in order to ensure airtightness between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder tube, a seal such as an O-ring or packing is provided on the outer peripheral surface of the piston. The member is installed. For the basic structure of such a fluid pressure cylinder, for example, issued by Ohm Co., Ltd.
It is described on pages 486 to 488 of the Oil and Air Handbook issued on the 25th of each month.

[0005]

In such a fluid pressure cylinder, since the seal member makes sliding contact with the inner peripheral surface of the cylinder tube when the piston moves, sliding resistance is applied to the piston. It will be. Therefore, the output of the piston rod, which is determined by the pressure receiving area of the piston on which the fluid pressure in the pressure chamber acts and the fluid pressure, is affected by the sliding resistance, and the stability of the output of the piston rod decreases. . For this reason, when applying pressure to the object by the piston rod after moving the piston rod forward, the pressure becomes unstable due to the sliding resistance of the seal member, and a constant pressure can be applied to the object. Disappear. In particular, in a pneumatic cylinder that operates a piston rod with a pressure lower than that of a hydraulic cylinder, the sliding resistance of the seal member has a large effect and the applied pressure becomes unstable.

Further, in a fluid pressure cylinder in which the piston rod is reciprocally moved in the vertical direction, gravity acts on the piston rod and the piston.
In addition to the thrust set by the fluid pressure, gravity is applied to the downward pressure applied to the object via the piston rod. For this reason, it is difficult to obtain a highly accurate pressing force, and it is not possible to set a pressing force smaller than the gravity acting on the piston or the piston rod.

An object of the present invention is to enable a piston rod driven by a fluid pressure to apply a constant pressing force to an object with high accuracy.

[0008]

A fluid pressure cylinder of the present invention comprises a piston that is axially reciprocally mounted in a cylinder body, and a piston that is supported by the piston so as to axially reciprocate and is pressurized by the piston. A piston rod that partitions the chamber and projects from the end of the cylinder body;
Mounted between the piston and the piston rod,
A balance diaphragm for partitioning and forming a balance pressure chamber, and the piston rod is moved forward by the fluid pressure of the pressure chamber in a state where the fluid pressure of the balance pressure chamber is applied to the piston rod in the backward direction. It is characterized by pressing in the direction.

The fluid pressure cylinder of the present invention is characterized in that it is provided between the piston and the piston rod, and has a closing diaphragm that partitions and forms the balance pressure chamber together with the balancing diaphragm.

The fluid pressure cylinder of the present invention is characterized in that it has a pressurizing diaphragm which is mounted between the piston and the piston rod and which partitions and forms the pressurizing chamber.

The fluid pressure cylinder of the present invention is a single-acting cylinder in which a forward pressure chamber for applying fluid pressure in the forward direction to the piston is provided in the cylinder body, and an external force in the backward direction is applied to the piston. It is characterized by

In the fluid pressure cylinder of the present invention, a forward pressure chamber for applying a fluid pressure in the forward direction to the piston is provided in the cylinder body, and a backward pressure chamber for applying a fluid pressure in the backward direction to the piston is provided. It is a double-acting type cylinder.

In the fluid pressure cylinder of the present invention, the piston is formed by a main piston member through which the piston rod penetrates, and a sub-piston member attached to the main piston member for restricting a movement stroke of the piston rod with respect to the main piston member. Is formed.

In the fluid pressure cylinder of the present invention, a pressure rod having a fluid supply passage communicating with the balance pressure chamber is projected from the other end of the cylinder body and mounted on the sub piston member. To do.

The fluid pressure cylinder of the present invention is characterized in that a fluid supply passage communicating with the pressurizing chamber is formed in the pressure rod.

The fluid pressure cylinder of the present invention is characterized in that a communication hole for communicating the pressurizing chamber and the advancing pressure chamber is formed in the sub piston member.

The fluid pressure cylinder of the present invention is characterized in that a fluid supply passage communicating with the balance pressure chamber is formed in the piston rod.

The fluid pressure cylinder of the present invention is characterized in that a fluid supply passage communicating with the pressurizing chamber is formed in the piston rod.

The fluid pressure cylinder of the present invention is characterized in that a rotation stopper is provided between the piston and the piston rod.

According to the present invention, by supplying the fluid pressure to the balance pressure chamber defined by the balancing diaphragm, a thrust force against the gravity can be applied to the piston rod in the backward direction, and the piston The gravity acting on the rod can be offset. Further, by supplying the fluid pressure to the pressure chamber defined by the piston and the piston rod, the piston rod can be pressed in the forward direction. With these, after moving the piston rod using the piston, it is possible to press the piston rod with high precision and stable output without being affected by the gravity acting on the piston rod or the sliding resistance of the piston. You can

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 2 are vertical sectional views showing a fluid pressure cylinder 10a according to an embodiment of the present invention. FIG. 1 shows a state in which a piston rod 11 is retracted, that is, raised, and FIG. In other words, it indicates a lowered state. 3 is a transverse sectional view taken along the line AA in FIG. 1, and FIG. 4 is an enlarged sectional view showing a part of FIG.

The fluid pressure cylinder 10a is a single-acting pneumatic cylinder using compressed air as a working fluid. The fluid pressure cylinder 10a is vertically attached to various devices (not shown) and projects from a cylinder body 12 to a piston rod 11a.
It is applied in order to press an object W made up of a work, a jig, a tool, or the like provided at the tip of the object R against an object R made up of various devices or equipment with a predetermined pressure.

As shown in FIG. 1, the cylinder tube 13
And the end covers 14a and 14b provided at both ends of the cylinder tube 13 form a cylinder assembly, that is, the cylinder body 12. In the illustrated fluid pressure cylinder 10a, for convenience of drawing, the cylinder tube 13 and the end covers 14a and 14b at both ends thereof are illustrated.
However, the cylinder main body 12 may be assembled by a screw member using these members as separate parts, and the two end covers 14a, 14b may be assembled.
Either one of them may be formed integrally with the cylinder tube 13. Also, the cylinder tube 13 is
As shown in FIG. 3, the cylinder tube is formed of a cylindrical member having a uniform thickness in the circumferential direction as a whole, but a member whose outer peripheral surface has a substantially rectangular cross section is used. 13 may be formed.

A piston 15 is incorporated in the cylinder body 12 so as to be reciprocally movable in the axial direction. This piston 1
5 has a main piston member 16 and a sub piston member 17, which are connected via a screw connection portion 18. The main piston member 16 includes an end plate portion 16a and a cylindrical portion 16
It has b and the annular part 16c, and these are integrally formed. On the other hand, the sub piston member 17 has the end plate portion 17
It has an a and an annular portion 17b which is integral with the a, and the screw coupling portion 18 is constituted by a female screw and a male screw formed on the respective annular portions 16c and 17b. However, the main piston member 16 and the sub piston member 17 may be connected by caulking without screwing them together, or may be connected by using a screw member.

The cylindrical portion 16b of the main piston member 16 has two
Two sleeves 20 and 21 are inserted in series. The inner peripheral surfaces of the sleeves 20 and 21 are smoothly cut, and a substantially cylindrical pressure receiving member 22 is incorporated in the sleeves 20 and 21 so as to be axially reciprocable. A rod collar 2 having a flange portion on the lower end surface of the pressure receiving member 22.
The rod member 24 is mounted via the pressure receiving member 22, the rod collar 23, and the rod member 24 to form the piston rod 11. The piston rod 11 is assembled so as to penetrate through the through holes 25 and 26 formed in the end plate portion 16a of the main piston member 16 and the end cover 14b of the cylinder body 12 and project from the cylinder body 12. . A large-diameter head 27 is integrally provided at the base end of the rod member 24.
The lower end surface of the piston abuts against the end plate portion 16a, so that the downward movement of the piston rod 11 is restricted. Further, the end cover 14b is provided with a slide bearing 28 for guiding the axial movement of the piston rod 11.

FIG. 4 is an enlarged vertical sectional view showing a part of FIG. As shown in FIG. 4, three diaphragms 31 to 33 partitioning and forming each pressure chamber are mounted in the piston 15. The diaphragm is a thin film component formed by laminating a cloth layer made of polyester or the like and a rubber layer, and divides each pressure chamber having a different pressure to convert a pressure change into a positional displacement. The diaphragm has a disk-shaped central portion 31a to 33a and an annular flange portion 31b to 3a.
3b, and the folded-back portions 31c to 33c are provided between the central portions 31a to 33a and the flange portions 31b to 33b.
The cylindrical portions 31d to 33d having an inner and outer double structure are provided through the. When the diaphragm operates, the folding portions 31c to 33c roll, so that sliding resistance does not occur.

Central part 3 of diaphragm 31 for balancing
1a is mounted between the pressure receiving member 22 and the rod collar 23, and the flange portion 31b is mounted between the two sleeves 20 and 21. The central portion 32a of the closing diaphragm 32 is mounted between the rod collar 23 and the head portion 27 of the rod member 24, and the flange portion 32b is mounted between the sleeve 21 and the main piston member 16. In this way, the diaphragm 3 for balancing and closing
A balance pressure chamber 34 is defined by the reference numerals 1 and 32, and a fluid supply passage communicating with the balance pressure chamber 34 is provided between the sleeves 20 and 21 and the sub piston member 17 in order to supply the fluid pressure to the balance pressure chamber 34. 35-37 are formed. Further, a pressure rod 39 projecting from a communication hole 38 formed in the end cover 14a is provided at the upper end of the sub piston member 17, and a pressure is supplied from a supply / discharge port 40 formed at the end of the pressure rod 39. Via the fluid supply passage 41 of the rod 39, the sub piston member 17
The compressed air is supplied to the fluid supply passage 37.

The balance pressure chamber 34 is formed by the rod member 2
Diaphragm 32 for closing provided on the head 27 of No. 4
And the balancing diaphragm 31 provided on the pressure receiving member 22 having a diameter larger than that of the head portion 27, the effective pressure receiving area of the balancing diaphragm 31 is set to be larger than that of the closing diaphragm 32. Will be. Therefore, when pressure is supplied to the balance pressure chamber 34, the balance pressure chamber 3 has a difference in effective pressure receiving area between the balancing diaphragm 31 and the closing diaphragm 32.
Thrust multiplied by the pressure in 4 is applied upward. At this time, when the piston rod 11 rises, the folded-back portion 31 of the diaphragms 31 and 32 for balancing and closing.
Both c and 32c rise, and when the piston rod 11 descends, both folding parts 31c and 32c descend. In this way, even when the piston rod 11 operates, the volume change of the balance pressure chamber 34 is suppressed, and the pressure fluctuation of the fluid pressure P4 is also suppressed low, so that stable thrust can be obtained from the balance pressure chamber 34. Become.

The central portion 33a of the pressure-applying diaphragm 33 is attached to the end surface of the pressure-receiving member 22, and the flange portion 3
3b is mounted between the sleeve 20 and the sub piston member 17, and the pressurization chamber 42 is defined by the diaphragm 33 for pressurization and the sub piston member 17. In order to supply pressure to the pressurizing chamber 42, the sub piston member 1
A communication hole 44 communicating with the fluid supply passage 43 of the pressure rod 39 is formed in 7, and compressed air is supplied to the pressurizing chamber 42 from a supply / discharge port 45 formed at the end of the pressure rod 39. ing. When pressure is supplied to the pressurizing chamber 42, downward thrust is applied to the piston rod 11 via the pressure receiving member 22.

As shown by the broken line in FIG. 4, the annular groove 4 formed in the sleeve 20 and the main piston member 16
6 to 48 are engaged with the diaphragm 31 respectively.
Beads may be provided on the flange portions 31b to 33b of the to 33. Further, a retainer may be attached to the end portion of the pressure receiving member 22 so as to cover the central portion 33a of the pressing diaphragm 33.

The downward movement of the piston rod 11 due to the supply of pressure to the pressurizing chamber 42 causes the end plate portion 1 of the main piston member 16 to move.
6a and the head 27 of the rod member 24 contact each other, and the upward movement of the piston rod 11 is restricted by the end plate portion 17a of the sub piston member 17 and the pressure receiving member 22 contacting each other. Therefore, the piston rod 11 is movable in the axial direction with a predetermined stroke with respect to the piston 15. As shown in FIG. 4, even when the piston rod 11 is at the most lowered position with respect to the piston 15, the folded portions 31c to 33c are formed on the three diaphragms 31 to 33. In addition, when the piston rod 11 rises and the pressure receiving member 22 and the sub piston member 17 come into contact with each other, the three diaphragms 31 to 31 are also brought into contact.
3, so that the folded-back portions 31c to 33c are formed,
The end plate portion 17a of the sub piston member 17 is set.

Further, in order to prevent the movement of the diaphragms 31 to 33 from being obstructed, a bleed port, that is, a breathing hole 51, is provided outside between the diaphragms 31 and 33 for balancing and pressurizing through the rod member 24. Is opened,
End plate portion 1 provided below the closing diaphragm 32
A breathing hole 52 is also formed in 6a.

Sealing members 53, 5 are provided on the outer circumference of the piston 15 to keep the space between the piston 15 and the inner circumference of the cylinder tube 13 airtight.
4, a descending pressure chamber 55 that supplies a pressure for moving the piston 15 in the descending direction with respect to the cylinder body 12 is defined as a forward pressure chamber between the piston 15 and the end cover 14a. A supply / discharge port 56 communicating with the pressure chamber is formed in the end cover 14a.

A spring chamber 57 is formed between the piston 15 and the end cover 14b, and a compression coil spring 58 for applying a spring force in the upward direction to the piston 15 is incorporated in the spring chamber 57. There is. Therefore, when compressed air is supplied from the supply / exhaust port 56, a downward thrust is applied to the piston 15, and the piston 15 moves downward together with the piston rod 11 against the spring force.
The lower limit position of the piston 15 is restricted by the stopper surface 59 provided on the end cover 14b.

On the other hand, when compressed air is discharged from the supply / discharge port 56, the piston 15 is moved by the thrust of the compression coil spring 58 in the upward direction. A breathing hole 60 is formed in the cylinder tube 13 for allowing the flow of air between the spring chamber 57 and the outside during these movements.

Further, the piston rod 11 is provided with a rotation stopping key 61 which engages with a key groove formed in the main piston member 16 so that the piston rod 11 does not rotate with respect to the piston 15. However, if the rod member 24 has a quadrangular cross-sectional shape, the rotation stop key 61 is not necessary. The cross-sectional shape is not limited to a quadrangle, and any shape other than a circle such as a polygon or an ellipse can be used. It can be applied even if there is.

The pressing operation of the object W against the object R performed using the fluid pressure cylinder 10a will be described below. As shown in FIG. 1, when compressed air is supplied from the supply / discharge port 56 to the descending pressure chamber 55 while the piston 15 is at the upper limit position, the piston 15 is pushed down. At this time, the object W is placed in the pressure chamber 42.
Fluid pressure P3 according to the pressing force when pushing the object R
Is supplied from the supply / discharge port 45, and the balance pressure chamber 34 has a fluid pressure P4 corresponding to the gravity acting on the piston rod 11.
Is supplied from the supply / discharge port 40. Therefore, the piston 15 moves downward against the spring force while the piston rod 11 is placed at the lower limit position, and the air in the spring chamber 57 is discharged to the outside from the breathing hole 60.

When the piston rod 11 descends as the piston 15 descends, as shown in FIG.
The piston rod 11 stops its downward movement when it contacts the object R, but the piston 15 continues its downward movement until it contacts the stopper surface 59. Due to the forward movement of only the piston 15, the head portion 27 of the rod member 24 is moved to the end plate portion 1.
The piston rod 11 moves away from 6a in the upward direction relative to the piston 15. Therefore,
The piston rod output applied to the object W from the piston rod 11 is set by the product of the fluid pressure P3 in the pressurizing chamber 42 and the effective pressure receiving area of the pressurizing diaphragm 33,
The sliding resistance between the seal members 53, 54 provided on the piston 15 and the inner peripheral surface of the cylinder tube 13 does not affect the piston rod output.

The fluid pressure P4 supplied to the balance pressure chamber 34 gives an upward thrust to the piston rod 11 against gravity. That is, a thrust force from the balance pressure chamber 34 is applied to the piston rod 11 that transmits the pressing force generated from the pressurizing chamber 42 to the object W so as to cancel the gravity acting on the piston rod 11. Therefore, for example, even when the object W is pressed by setting a pressure force that is less than the gravity acting on the piston rod 11, the piston rod output can be set with high accuracy.

A constant pressure is applied to the object W in this way, as shown in FIG. 2, a gap S1 is formed above the pressure receiving member 22, and a gap S2 is formed below the head 27. When the piston rod 11 is in the floating state when it occurs, even if an error occurs in the lower limit position of the piston rod 11, if the floating state is secured, a constant pressing force is applied to the object W. Is added.
As described above, the pressure applied to the object W is set by the product of the fluid pressure P3 applied to the pressure-applying diaphragm 33 and the effective pressure receiving area, and acts on the piston rod 11 due to the influence of the sliding resistance of the seal members 53 and 54. Since it is not affected by gravity, the pressing force can be set with high accuracy. Further, even if a rotational force is applied to the piston rod 11 during floating, the rotation stop key 61 does not cause relative rotation between the piston 15 and the piston rod 11, and damage to the diaphragms 31 to 33 due to twisting is prevented.

Next, when the compressed air is discharged from the supply / discharge port 56 after the pressurizing work of the object W on the object R is completed, first, the piston 15 moves upward by the spring force. Due to the subsequent upward movement, the head 27 is moved to the end plate portion 16a.
After coming into contact with the piston 15, the piston 15 ascends together with the piston rod 11 to the ascending limit position.

FIG. 5 is a vertical cross-sectional view showing a fluid pressure cylinder 10b according to another embodiment of the present invention. In FIG. 5, the same members as those in the above-described embodiment are designated by the same reference numerals. It is attached. This fluid pressure cylinder 10
In FIG. 1b, the fluid pressure cylinder 10a shown in FIG. 1 is modified into a double-acting type, and pressure chambers are formed on both sides of the piston 15. One pressure chamber is a backward pressure chamber for the piston 15, that is, an ascending pressure chamber 62, and the other pressure chamber is a descending pressure chamber 55. A supply / discharge port 63 communicating with the rising pressure chamber 62 is formed in the cylinder tube 13, and when the piston 15 is moved up from the lower limit position to the upper limit position, compressed air is supplied from the supply / discharge port 63. Compressed air will be discharged from the supply / discharge port 56.
In order to prevent the air in the rising pressure chamber 62 from leaking to the outside, the end cover 14b is provided with a seal member 64. Then, the breathing hole 60 of the cylinder tube 13 provided in the fluid pressure cylinder 10a is closed.
Further, in order to prevent inversion that may occur in the folded portion 32c of the closing diaphragm 32, the fluid pressure P2 supplied to the rising pressure chamber 62 is set smaller than the fluid pressure P4 supplied to the balance pressure chamber 34. To be done.

When the piston 15 of the fluid pressure cylinder 10b descends, compressed air is discharged from the supply / exhaust port 63 and compressed air is supplied from the supply / exhaust port 56, while when the piston 15 rises, the compressed air is compressed to the supply / exhaust port 63. By supplying air and discharging compressed air from the supply / discharge port 56, it can be used in the same manner as the fluid pressure cylinder 10a described above.

6 and 7 are vertical sectional views showing fluid pressure cylinders 10c and 10d according to still another embodiment of the present invention. In FIGS. 6 and 7, the same members as those in the above-described embodiment are used. The same reference numerals are given to the members that perform. These fluid pressure cylinders 10c and 10d are
In the fluid pressure cylinders 10a and 10b, the pressurizing chamber 42 defined by the diaphragm 33 for pressurization is
Pressure receiving member 2 without using a diaphragm 33 for pressurization
2 and the sub piston member 17 are used to form a partition.

As shown in FIGS. 6 and 7, the pressurizing chamber 42 for pressing the piston rod 11 is defined by the pressure receiving member 22 and the sub piston member 17, and is transmitted to the object W via the piston rod 11. The pressure applied by the pressure receiving member 2
It is set by the product of the effective pressure receiving area of 2 and the fluid pressure P3. Further, in order to prevent inversion that may occur at the folded back portion of the balancing diaphragm 31, the fluid pressure P3 supplied to the pressurizing chamber 42 is set smaller than the fluid pressure P4 supplied to the balance pressure chamber 34. It in this way,
When the piston rod output is set to be relatively small, the pressurizing diaphragm 33 can be removed and the breathing hole 51 formed in the piston rod 11 can be eliminated. Accordingly, the fluid pressure cylinder having a simple structure can be provided, and the low cost fluid pressure cylinder can be provided.

The fluid pressure cylinders 10a to 10a described above.
10d uses the piston 15 to move the piston rod 11 down to a predetermined position.
1 is being moved, and when applying a pressing force to the object W from the piston rod 11, the piston rod 11 is floated with respect to the piston 15, and the pressing force is set by the fluid pressure P3 of the pressurizing chamber 42. Therefore, when applying a pressure to the object W, the seal member 5 is attached to the piston rod 11.
Since the sliding resistance of 3, 54 is not applied and the deformation stroke of the diaphragm can be set short by the downward movement of the piston rod 11 by the piston 15, even when the piston rod 11 is reciprocated with a long stroke, It is possible to stably apply a highly accurate pressing force with a small error to the object W. Further, by forming the balance pressure chamber 34 that cancels the gravity applied to the piston rod 11, it is possible to set a highly accurate pressing force that is not affected by the gravity when the object W is pressurized.

As described above, since the pressing force can be applied to the object with high accuracy, it can be used, for example, to press the squeegee head in screen printing with a constant pressure. In screen printing, ink is silk-screened using a rubber squeegee,
The mesh of a paint screen, a stencil screen, etc. is pressed against paper or cloth, and the fluid pressure cylinder 10a of the present invention is used to drive the squeegee.
-10d can be used. In addition, what kind of thing, such as a chip mounter that mounts a semiconductor chip on a mounting board or a tension roller of a winding machine, if a certain pressing force is applied to the object after moving the object by a predetermined stroke The present invention can also be applied to.

The present invention is not limited to the above-described embodiment, but various modifications can be made without departing from the scope of the invention. For example, in the illustrated embodiment, the compressed air is used for the operation, but hydraulic oil may be used as the working fluid. Further, the balance pressure chamber 34 is not only partitioned and formed by the balancing and closing diaphragms 31 and 32, but also the breathing hole 52 provided in the end plate portion 16 a of the main piston member 16.
The obstructing diaphragm 32 may be removed, and the balance pressure chamber 34 may be defined by only the balancing diaphragm 31.

Further, as shown by the chain double-dashed line in FIG. 6, a communication hole 65 may be formed in the sub piston member 17 to connect the advancing pressure chamber 55 and the pressurizing chamber 42. In this case, the supply / discharge port 45 formed in the pressure rod 39 and the fluid supply passage 4
3 is removed. During the operation of the fluid pressure cylinder 10c, the fluid pressure P1 from the supply / discharge port 56 is changed to the forward pressure chamber 5
5, the piston 15 is moved downward, and the piston rod 11 is pressed by the fluid pressure P1 that is also supplied to the pressurizing chamber 42. At this time, the fluid pressure P1 is set smaller than the fluid pressure P4 in order to prevent inversion that may occur in the folded-back portion 31c of the balancing diaphragm 31. The communication hole 65 is formed in the fluid pressure cylinder 10.
It can also be formed in a, 10b, and 10d.

Further, with respect to the fluid pressure cylinders 10a to 10d, the supply / discharge ports 40 and 4 formed in the pressure rod 39.
5 and the fluid supply channels 41, 43 may be formed in the piston rod 11 so as to communicate with the balance pressure chamber 34 and the pressurizing chamber 42, respectively, whereby the pressure rod 39 can be removed, which is simple. Fluid pressure cylinder 10a
It is also possible to provide 10d.

Further, the pressure receiving member 22 and the rod collar 23
Needless to say, the piston rod 11 may be formed of one member by integrally forming the rod member 24 and the rod member 24. Needless to say, a precision pressure reducing valve may be provided on the upstream side of the supply / discharge port 40 so that the fluid pressure P4 is always kept constant.

The fluid pressure cylinders 10a to 10d may be mounted not only vertically on various devices but also may be mounted so as to be inclined. That is, even when a part of gravity acting on the piston rod 11 affects the operation of the piston rod 11, the fluid pressure cylinders 10a to 10d of the present invention can be applied.

[0053]

According to the present invention, by supplying the fluid pressure to the balance pressure chamber defined by the balancing diaphragm, the thrust force against the gravity can be applied to the piston rod in the backward direction. , It is possible to cancel the gravity acting on the piston rod. Further, by supplying the fluid pressure to the pressure chamber defined by the piston and the piston rod, the piston rod can be pressed in the forward direction. With these, after moving the piston rod using the piston, it is possible to press the piston rod with high precision and stable output without being affected by the gravity acting on the piston rod or the sliding resistance of the piston. You can

In addition to the balancing diaphragm, the closing pressure diaphragm mounted to the piston and the piston rod is used to define the balancing pressure chamber, thereby suppressing the volume change of the balancing pressure chamber with respect to the stroke of the piston rod. Therefore, it is possible to suppress the pressure fluctuation in the balance pressure chamber. As a result, the self-weight acting on the piston rod can be canceled with high accuracy.

By partitioning and forming the pressurizing chamber using the pressurizing diaphragm, the fluid pressure supplied to the pressurizing chamber can be increased and the piston rod can be pressed with high output.

A balance pressure chamber defined by a piston reciprocating with respect to the cylinder body is provided by projecting from the cylinder body a pressure rod in which a fluid supply passage communicating with the balance pressure chamber is formed and provided on the sub piston member. , The fluid pressure can be reliably and easily supplied.

By forming a fluid supply passage communicating with the pressure chamber in the pressure rod, the fluid pressure can be reliably and easily supplied to the pressure chamber defined by the piston that reciprocates with respect to the cylinder body. can do.

By forming the communication hole for communicating the pressurizing chamber and the advancing pressure chamber in the sub piston member, it is possible to provide a fluid pressure cylinder having a simple structure. Further, by forming the fluid supply passage communicating with the pressure chamber and the balance pressure chamber in the piston rod, it is possible to provide a fluid pressure cylinder having a simple structure.

By providing the rotation stopper, the relative rotation of the piston rod with respect to the piston is prevented, so that the durability of the diaphragm can be improved. As a result, the reliability of the fluid pressure cylinder and the accuracy of the applied pressure can be improved, and an excellent fluid pressure cylinder that is low in cost and easy to use can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a fluid pressure cylinder that is an embodiment of the present invention showing a state in which a piston has moved backward.

FIG. 2 is a vertical cross-sectional view of the fluid pressure cylinder of FIG. 1 showing a state in which a piston has moved forward.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an enlarged sectional view showing a part of the fluid pressure cylinder of FIG.

FIG. 5 is a vertical sectional view of a fluid pressure cylinder according to another embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a fluid pressure cylinder which is still another embodiment of the present invention.

FIG. 7 is a vertical sectional view showing a fluid pressure cylinder which is still another embodiment of the present invention.

[Explanation of symbols]

10a-10d Fluid pressure cylinder 11 piston rod 12 cylinder body 13 cylinder tube 14a, 14b end covers 15 pistons 16 Main piston member 16a End plate part 16b cylindrical part 16c annular part 17 Secondary piston member 17a End plate part 17b Ring part 18 Screw connection 20,21 sleeve 22 Pressure receiving member 23 Rod color 24 Rod member 25,26 through holes 27 heads 28 Sliding bearing 31 Balance diaphragm 32 Diaphragm for closure 33 Pressurizing diaphragm 31a to 33a Central part 31b-33b Flange part 31c-33c folding part 31d-33d cylindrical part 34 Balance pressure chamber 35-37 Fluid supply passage 38 communication holes 39 Pressure rod 40 supply / discharge port 41 Fluid supply passage 42 Pressurization chamber 43 Fluid supply passage 44 communication hole 45 supply / discharge port 46-48 annular groove 51,52 breathing hole 53,54 Seal member 55 Down pressure chamber (forward pressure chamber) 56 Supply / Discharge port 57 Spring chamber 58 Compression coil spring 59 Stopper surface 60 breathing hole 61 Rotation stop key (rotation stop) 62 Ascending pressure chamber (reverse pressure chamber) 63 supply / discharge port 64 seal member 65 communication holes P1 to P4 fluid pressure

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F15B 15/14 375 F15B 15/14 375 (72) Inventor Atsushi Sasaki 3-8 Iwamotocho, Chiyoda-ku, Tokyo No. 16 In stock company in Koganei (72) Inventor Kazutoshi Kono 3-8-16 Iwamotocho, Chiyoda-ku, Tokyo F term in stock company in Koganei (reference) 3H081 AA04 AA09 AA10 AA15 BB03 BB14 CC11 CC25 DD02 DD06 DD17 DD32 EE03 EE23 FF18 HH04

Claims (12)

[Claims] 1. A piston incorporated in a cylinder body so as to reciprocate in the axial direction, and a piston movably supported in the piston so as to reciprocate in the axial direction. The piston defines a pressurizing chamber and an end portion of the cylinder body. Mounted from between the piston and the piston rod,
A balance diaphragm for partitioning and forming a balance pressure chamber, wherein the piston rod is moved forward by the fluid pressure of the pressure chamber in a state where the fluid pressure of the balance pressure chamber is applied to the piston rod in the backward direction. A fluid pressure cylinder that presses in a direction. 2. The fluid pressure cylinder according to claim 1, further comprising a closing diaphragm that is mounted between the piston and the piston rod and that partitions the balance pressure chamber together with the balancing diaphragm. Characteristic fluid pressure cylinder. 3. A fluid pressure cylinder according to claim 1, further comprising a pressurizing diaphragm that is mounted between the piston and the piston rod and defines and forms the pressurizing chamber. Pressure cylinder. 4. The fluid pressure cylinder according to claim 1, wherein a forward pressure chamber that applies forward fluid pressure to the piston is provided in the cylinder body, and the forward pressure chamber is provided with respect to the piston. A fluid pressure cylinder characterized by being a single-acting type cylinder that applies an external force in the backward direction. 5. The fluid pressure cylinder according to claim 1, wherein a forward pressure chamber that applies forward fluid pressure to the piston is provided in the cylinder body, and the forward pressure chamber is provided with respect to the piston. A fluid pressure cylinder characterized by being a double-acting type cylinder provided with a retreating pressure chamber for applying a fluid pressure in a retreating direction. 6. The fluid pressure cylinder according to claim 1, wherein a main piston member through which the piston rod penetrates, and the piston rod attached to the main piston member with respect to the main piston member. A fluid pressure cylinder, characterized in that the piston is formed by an auxiliary piston member that regulates a movement stroke. 7. The fluid pressure cylinder according to claim 6, wherein a pressure rod having a fluid supply passage communicating with the balance pressure chamber is protruded from the other end of the cylinder body and is attached to the sub piston member. A fluid pressure cylinder characterized in that 8. The fluid pressure cylinder according to claim 7, wherein a fluid supply passage communicating with the pressurizing chamber is formed in the pressure rod. 9. The fluid pressure cylinder according to claim 6, wherein a communication hole that communicates the pressurization chamber and the forward pressure chamber is formed in the sub piston member. 10. The fluid pressure cylinder according to claim 1, wherein a fluid supply passage communicating with the balance pressure chamber is formed in the piston rod. 11. The fluid pressure cylinder according to claim 1, wherein a fluid supply passage communicating with the pressurizing chamber is formed in the piston rod. 12. The fluid pressure cylinder according to claim 1, further comprising a rotation stopper provided between the piston and the piston rod.