JP2000320504A - Fluid pressure cylinder and tail-end cover thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure cylinder capable of increasing the moving velocity of a piston. SOLUTION: A first supply/discharge port 23 is communicated with a left side pressure acting chamber 19 distant from each port 23, 24 via both through- holes 16a, 16b. The second supply/discharge port 24 is communicated with a right side pressure actin chamber 20 near from each port 23, 24. The first supply/discharge port 23 is communicated with one pressure acting chamber 19 placed on an opposite side to each port 23, 24 via both the through-holes 16a, 16b. An effective sectional area of a channel can be thereby made approximately 2 times as large as those of the conventional ones to increase moving velocity of a piston 14 and a piston yoke 15, without enlarging a diameter of each through hole 16a, 16b even though the pressure acting chamber 19 is located at a distant from each port 23, 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic cylinder and its end cover.

[0002]

2. Description of the Related Art Conventionally, among various cylinders utilizing fluid pressure, a rodless cylinder 81 shown in FIGS. The rodless cylinder 81 includes a cylinder tube 83 having a piston housing space 82. The housing space 82 is formed by a pair of pressure action chambers 85 by a piston 84 provided therein.
a, 85b. Also, the cylinder tube 8
3, a through hole 88a is formed along the longitudinal direction.

[0003] At both ends of the cylinder tube 83, two end covers 86 and 87 are provided. The right end cover 87 has first and second supply / discharge ports 90, 9.
1 is formed. And the first supply / discharge port 90 is
The port 90 is communicated with a left pressure action chamber 85a on the opposite side of the port 90 through a through hole 88a and an air passage 92 formed in the left end cover 86. On the other hand, the second supply / discharge port 91 is connected to the port 91 without passing through the through hole 88a.
And directly communicates with the right side pressure action chamber 85b on the same side as.

According to the rodless cylinder 81 configured as described above, when air is supplied to the first supply / discharge port 90, air is introduced into the left pressure action chamber 85a, and the piston 84 is moved to the right side in FIG. Go to On the other hand, when air is supplied to the second supply / discharge port 91, air is introduced into the right pressure action chamber 85b, and the piston 84 moves to the left.

A rodless cylinder 81 of the type described above
, Another through hole 88b is formed separately from the through hole 88a. Both through holes 88a, 88b are
The positions are symmetrical about the axis of the rodless cylinder 81. As shown in FIG. 4A, when centralized piping is performed on the right side of the rodless cylinder 81, only the one through hole 88a communicates with the other through hole 88.
The openings at both ends of b are closed by both end covers 86 and 87. On the other hand, as shown in FIG. 5, when centralized piping is performed on the left side of the rodless cylinder 81, only the other through-hole 88b communicates with the other through-hole 8b.
Openings at both ends of 8 a are closed by both end covers 86 and 87. As described above, the two through holes 88a, 88b
The reason is that centralized piping can be performed from either the left or right side of the rodless cylinder 81.

[0006]

However, in the conventional rodless cylinder 81, when centralized piping is performed, only one of the two through holes 88a and 88b is used, and Is not used. Therefore, the pressure action chamber 8 on the opposite side to the ports 90 and 91
5a (85b), when air is introduced, the through holes 8
The effective cross-sectional area of the flow path 8a (88b) becomes smaller than the actual cross-sectional area. In short, the effective cross-sectional area of the passage 88a (88b) decreases in inverse proportion to the length of the rodless cylinder 81. In particular, if the rodless cylinder 81 is a long type (having a length of 1 m or more), the through holes 88a (8
The effective cross-sectional area of the passage 8b) becomes extremely small. Therefore,
There is a problem that the moving speed of the piston 84 decreases.

Therefore, in order to solve the above-mentioned problem, it is conceivable to increase the diameter of the through holes 88a (88b) and increase the effective sectional area of the flow passage. However, when the diameter of the through-hole 88a (88b) is increased, the above-described problem can be solved, but the axis of the through-hole 88a (88b) tends to be displaced during molding. That is, there is a problem that the processing accuracy of the cylinder tube 83 is deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fluid pressure cylinder capable of increasing a moving speed of a piston and an end cover thereof.

[0009]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a piston accommodating space and a plurality of through holes are formed in a cylinder main body and extend along the longitudinal direction thereof. The housing space is divided into a pair of pressure action chambers by a piston provided therein, and fluid is alternately supplied to each pressure action chamber from first and second supply / discharge ports provided at one end of the cylinder body. Thereby, in the fluid pressure cylinder in which the piston is moved along the longitudinal direction of the housing space, the first supply / discharge port is connected to at least two other end portions of the cylinder body through at least two or more of the through holes. And the second supply / discharge port is connected to the other pressure action chamber.

[0010] According to the second aspect of the present invention, the first and second supply units are arranged at the end of a cylinder tube having a piston accommodating space and a plurality of through holes, and supply fluid to the piston accommodating space. In a fluid pressure cylinder end cover provided with a discharge port, a branch passage for communicating the first supply / discharge port with at least two or more of the through holes, and the second supply / discharge port is directly connected to the piston housing space. The gist of the invention is to provide a communication path for communication.

According to the third aspect of the present invention, the first and second supply units are arranged at the end of a cylinder tube having a piston accommodating space and a plurality of through holes, and for supplying a fluid to the piston accommodating space. In the end cover for a fluid pressure cylinder provided with a discharge port, the gist is that a plurality of fluid passages for communicating all of the through holes with the piston accommodating space are provided.

The "action" of the present invention will be described below. According to the first aspect of the invention, the fluid supplied to the first supply / discharge port is introduced into one of the pressure action chambers on the opposite side to the port through the branch passage and the two or more through holes. . Thereby, even if the pressure action chamber is located far from the port, the fluid flows through the two or more through-holes, so that the effective cross-sectional area of the through-hole increases. Therefore, the moving speed of the piston can be increased, and as a result, the operability of the hydraulic cylinder is improved.

According to the second aspect of the invention, the fluid supplied to the first supply / discharge port is introduced into the piston accommodating space via the branch passage and the two or more through holes. Therefore,
Since the effective cross-sectional area of the flow path is increased, the moving speed of the piston can be increased, and as a result, the operability of the fluid pressure cylinder is improved.

According to the third aspect of the invention, the fluid supplied to all the through holes is introduced into the piston accommodating space via the fluid passage. Therefore, the effective cross-sectional area of the flow path increases, so that the moving speed of the piston can be increased, and as a result, the operability of the fluid pressure cylinder is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is embodied in a rodless cylinder will be described in detail with reference to the drawings.

As shown in FIGS. 1A and 1B, a cylinder tube 12 constituting a rodless cylinder 11 is
It is a long member having a substantially rectangular cross section and a cylindrical shape. The cylinder tube 12 is an extruded product such as aluminum. In addition,
The cylinder tube 12 may be a pultruded product. A slit 13 is formed in the center of the upper surface 12a of the cylinder tube 12. The slit 13 extends along the tube longitudinal direction and communicates inside and outside the cylinder tube 12.

Inside the cylinder tube 12, there is a space (piston accommodating space) 12b for accommodating the entire piston 14 and a part of the piston yoke 15. The pistons 14 are provided in a left and right pair with the piston yoke 15 interposed therebetween. Due to the presence of the piston 14 and the piston yoke 15, the space 12b in the cylinder tube 12 has a left pressure action chamber 19 and a right pressure action chamber 20.
Is divided into two areas.

A pair of through holes 16a and 16b are formed in the lower part of the cylinder tube 12 and extend in the longitudinal direction. Each of the through holes 16a and 16b is formed at a position farthest from the slit 13. this is,
This is because the shape of the edge of the slit 13 is complicated, so that the number of formed portions such as holes around the slit 13 is reduced, so that the cylinder tube 12 can be easily extruded.

First and second end covers 21 and 2 as end-face closing members are provided at both ends of the cylinder tube 12.
2 are provided. Each of the end covers 21 and 22 is detachably attached to the cylinder tube 12 by screws (not shown). Therefore, the first end cover 21 on the left side in FIG. 1A can be attached to the right side in FIG. Also, the second end cover 22 on the right side of FIG. 1A can be attached to the left side of FIG.

A first supply / discharge port 23 and a second supply / discharge port 24 are formed in the second end cover 22 located on the right side of FIG. Both supply / discharge ports 23 and 24 are respectively opened on the same surface (ie, outer end surface) of the second end cover 22. Therefore, the rodless cylinder 1
A centralized pipe is provided on the right side of 1. In the present embodiment, the cylinder body is constituted by the cylinder tube 12 and both end covers 21 and 22.

A branch passage 25 is formed in the second end cover 22, and the branch passage 25 is branched into two on the left side in FIG. The first supply / discharge port 23 communicates with the through holes 16a and 16b via the branch passage 25. Around the branch opening of the branch passage 25,
The packing 26 is interposed. This packing 26
It functions to prevent air as a fluid flowing through the branch passage 25 from leaking from between the cylinder tube 12 and the second end cover 22.

The second end cover 22 has a communication passage 27.
Is formed, and this communication passage 27 is located above the branch passage 25. The second supply / discharge port 24 communicates with the right pressure chamber 20 via the communication passage 27. That is, the second supply / discharge port 24 is connected to each through hole 16a,
It is directly communicated with the right pressure action chamber 20 without passing through 16b.

The first end cover 21 has a plurality of (two in this embodiment) fluid passages 30a and 30b. Each fluid passage 30a, 30b is formed in a horizontal U-shape. One end of each of the fluid passages 30a, 30b is opened corresponding to the through holes 16a, 16b.
The other end of each fluid passage 30a, 30b is connected to the left pressure action chamber 1
9 respectively. And each through-hole 16a,
16b communicates with the left pressure action chamber 19 via the respective fluid passages 30a and 30b. That is, all of the two through holes 16a and 16b are
Is communicated to. Further, a part of the fluid passages 30a and 30b is shared. And the common part 31 is
It is open to the left pressure action chamber 19.

The common portion 31 of each fluid passage 30a, 30b
Packings 32 are interposed around the openings on the opposite side from the opening. The packing 32 is provided in each of the fluid passages 3.
It functions to prevent the air flowing through Oa and 30b from leaking from between the cylinder tube 12 and the first end cover 21.

Next, the operation of the thus constructed rodless cylinder 11 will be described. When pressurized air is supplied from a pressure supply source (not shown) to the first supply / discharge port 23, the pressurized air is supplied to the left pressure action chamber 19 via the branch passage 25, the through holes 16a, 16b, and the fluid passages 30a, 30b. Introduced within. Then, the piston 14 is pressed rightward in FIG. 1A by the pressure of the pressurized air. As a result, the piston 14 and the piston yoke 15 are
Move linearly and integrally to the right side of. At the same time, the air in the right pressure action chamber 20 is discharged outside through the communication passage 27 and the second supply / discharge port 24.

When pressurized air is supplied to the second supply / discharge port 24, the pressurized air is supplied to the right pressure action chamber 2 through the communication passage 27.
0 is introduced. Then, the piston 14 is pressed in the leftward direction in FIG. 1A by the pressure of the pressurized air. As a result, the piston 14 and the piston yoke 15
(A) linearly and integrally moving toward the left side. At the same time, the air in the left pressure action chamber 19 is
Oa and 30b, the through holes 16a and 16b, the branch passage 25, and the first supply / discharge port 23 discharge the air to the outside.

Here, in the rodless cylinder 11 shown in FIG. 1A, a centralized pipe is provided on the right side of the figure. In order to perform centralized piping on the left side, it is necessary to reverse the positional relationship between the first and second end covers 21 and 22. That is, the screws fixing the end covers 21 and 22 are loosened and removed. Then, as shown in FIG. 2, the first end cover 21 is attached to the right end of the cylinder tube 12 again, and the second end cover 22 is attached to the left end of the cylinder tube 12 again.

By changing the arrangement of the end covers 21 and 22, the first supply / discharge port 23 is connected to the branch passage 2.
5. Through holes 16a, 16b and fluid passages 30a, 30b
Is connected to the right side pressure action chamber 20 through the second side. Further, the second supply / discharge port 24 is connected to the left pressure action chamber 1 through the communication passage 27.
9 is communicated. Therefore, not only the case where the centralized piping is performed on the right side of the rodless cylinder 11 but also the two through holes 16a and 16b are not closed by the first and second end covers 21 and 22 on the left side. Therefore, the pressure action chamber 19 on the opposite side to the ports 24 and 33
In (20), when air is introduced, the effective cross-sectional area of the flow path of the pressurized air does not decrease.

When pressurized air is supplied to each of the supply / discharge ports 23, 24, the direction in which the second supply / discharge port 24 moves is opposite to that in the case described above. That is, when pressurized air is supplied to the first supply / discharge port 23 from a pressure supply source (not shown), the pressure of the pressurized air causes the piston 14 and the piston yoke 15 to linearly move toward the left side in FIG. Move together. When the pressurized air is supplied to the second supply / discharge port 24, the pressure of the pressurized air causes the piston 14 and the piston yoke 15 to move linearly and integrally in the rightward direction in FIG. 1A.

Therefore, according to the present embodiment, the following effects can be obtained. (1) When centralized piping is performed on the right side of the rodless cylinder 11, the first supply / discharge port 23 is connected to both through holes 16a, 1
6b, it is connected to the left pressure action chamber 19 far from each of the ports 23, 24. Further, the second supply / discharge port 24 is communicated with the right pressure action chamber 20 located near each of the ports 23, 24. On the other hand, rodless cylinder 1
If centralized piping is to be performed on the left side of
3 through each through-hole 16a, 16b, each port 23,
It is in communication with the right pressure action chamber 20 remote from 24. Further, the second supply / discharge port 24 is communicated with the left pressure action chamber 19 near each of the ports 23, 24.

For this reason, the first supply / discharge port 23 is connected to one of the pressure action chambers 19 (or 20) on the opposite side to each of the ports 23, 24 via the two through holes 16a, 16b. Therefore, even if the position of the pressure action chamber 19 (or 20) is far from each of the ports 23 and 24, each of the through holes 16a,
The effective cross-sectional area of the flow passage can be approximately doubled without increasing the diameter of 16b, and the moving speed of the piston 14 and the piston yoke 15 can be increased. As a result, the operability of the rodless cylinder 11 can be improved.

Further, the piston 14 and the piston yoke 1 can be formed without increasing the diameters of the through holes 16a and 16b.
Since the moving speed of the cylinder tube 12 can be increased, the processing accuracy of the cylinder tube 12 does not deteriorate.

(2) Each of the end covers 21 and 22 is detachable from the cylinder tube 12. Therefore, centralized piping can be performed from either the left or right side of the rodless cylinder 11. In addition, the first supply / discharge port 23 can be communicated with both the through holes 16a and 16b regardless of whether the centralized piping is performed from the left or the right. Therefore, the moving speed of the piston 14 and the piston yoke 15 can be increased irrespective of whether the centralized piping is performed from the left or the right.

(3) Each through-hole 16a, 16b is formed in the lower part of the cylinder tube 12. For this reason,
The cylinder tube 12 can be formed more easily than when the through holes 16a and 16b are near the slit 13. At the same time, the center positions of the through holes 16a and 16b are less likely to shift when the cylinder tube 12 is formed. Therefore, the cylinder tube 12 can be formed with high processing accuracy. (Second Embodiment) Next, a second embodiment in which the present invention is embodied in a hydraulic cylinder 1 with a rod will be described in detail.

As shown in FIGS. 3A to 3C, the fluid pressure cylinder 41 of this embodiment includes a cylindrical cylinder tube 42. Of the openings in the cylinder tube 42, the opening on the right side in FIG. 3B is closed by a head cover 43 as an end cover. The opening on the left side in FIG. 3B is closed by a rod cover 44 as an end cover. In this embodiment, a cylinder body includes a cylinder tube 42, a head cover 43, and a rod cover 44.

A pair of through holes 46a and 46b are formed in the upper part of the cylinder tube 42 and extend along the longitudinal direction. Each of the through holes 46a and 46b extends in parallel along the longitudinal direction of the cylinder tube 42. The head side openings of the through holes 46a and 46b are sealed
7 closed.

A piston 50 is provided in an internal space (piston accommodating space) 42b formed in the cylinder tube 42.
Are slidably received in the longitudinal direction of the tube. The internal space 42b is divided into two regions, a rod-side pressure operation chamber 51 and a head-side pressure operation chamber 52, by the presence of the piston 50. A base end of a rod 53 is fixed to the center of the piston 50. The distal end of the rod 53 projects outside through a rod insertion hole 54 formed at the center of the rod cover 44. An annular rod packing 55 is mounted on the inner peripheral surface of the rod insertion hole 54. This rod packing 5
5, sealing between the peripheral surface of the rod 53 and the inner wall surface of the rod insertion hole 54 is achieved.

A first supply / discharge port 57 and a second supply / discharge port 58 are formed in the head cover 43. The two supply / discharge ports 57 and 58 are respectively opened on the same surface of the head cover 43. Therefore, centralized piping is performed on the head side of the fluid pressure cylinder 41.

The first supply / discharge port 57 includes a branch passage 59 formed in the head cover 43, the through holes 46a,
It communicates with the rod side pressure action chamber 51 via 46b. The second supply / discharge port 58 is directly connected to the head-side pressure action chamber 52 via a communication passage 60 formed in the head cover 43. That is, the second supply / discharge port 58
It communicates with the head side pressure action chamber 52 without passing through the through holes 46a and 46b.

Next, the operation of the fluid pressure cylinder 41 configured as described above will be described. As shown in FIG. 1, when pressurized air is supplied to the second supply / discharge port 58 in a state where the piston 50 is at the stroke end on the head side, air is supplied into the head side pressure action chamber 52 via the communication passage 60. Introduced, the pressure in the same chamber 52 rises. Then, the piston 50 and the rod 53 move in the direction of the rod side (that is, the left side in FIG. 3B). At the same time, the air in the rod-side pressure action chamber 51 flows through the through holes 46a and 46b, the branch passage 59, and the first
It is discharged to the outside via the supply / discharge port 57.

Although not shown, the first supply / discharge port 57 is provided with the piston 50 at the rod-side stroke end.
Is supplied to the branch passage 59, the through holes 46a,
Air is introduced into the rod side pressure action chamber 51 via 46b, and the pressure in the chamber 51 rises. Then, the piston 50 moves in the direction of the head (ie, the right side in FIG. 3B). At the same time, the air in the head side pressure action chamber 52 is discharged to the outside through the communication passage 60 and the second supply / discharge port 58.

Therefore, in the second embodiment, substantially the same effects as in the first embodiment can be exerted. In short, the first supply / discharge port 57 communicates with the rod-side pressure action chamber 51 on the opposite side to each of the ports 57, 58 via the two through holes 46a, 46b. The second supply / discharge port 58 communicates with the head side pressure action chamber 52. Therefore, even if the position of the rod side pressure action chamber 51 is far from each of the ports 23 and 24, each of the through holes 46a and 4
Without increasing the diameter of 6b, it is possible to secure approximately twice the effective cross-sectional area of the flow passage, and to increase the moving speed of the piston 14 and the rod 53.

The embodiment of the present invention may be modified as follows. -As another example of the first embodiment, the fluid passages 30a, 30
b, instead of forming a common portion 31 of each fluid passage 3
0a and 30b may be formed completely independently of each other.

As another example of the first and second embodiments,
Three or more through holes may be formed in the cylinder tubes 12 and 42. In this case, the branch passage 25 is branched into three or more places in accordance with the number of through holes, and the fluid passage 3
The number of 0a and 30b is also three or more. Therefore, according to this configuration, the effective sectional area of the flow path can be further increased, and the moving speed of the pistons 14, 50 can be further increased.

As another example of the first and second embodiments,
First supply / discharge ports 23, 57 and second supply / discharge ports 24, 5
The openings 8 may not be opened on the same plane, but may be opened on different planes.

As another example of the first and second embodiments,
First supply / discharge ports 23, 57 and second supply / discharge ports 24, 5
Another first and second supply / discharge ports may be opened on a surface different from the surface on which 8 is opened. When this configuration is adopted, unused ports are closed with a hermetic plug.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) A fluid pressure cylinder, wherein two through holes are provided. According to this configuration, since the number of through holes is minimized, the cylinder body can be formed with high accuracy.

(2) A piston accommodating space and a plurality of through holes are formed in the cylinder tube and extend in the longitudinal direction thereof. The accommodating space is divided into a pair of pressure action chambers by a piston provided therein. A cylinder extending along the longitudinal direction of the cylinder tube and communicating with the inside and outside of the cylinder tube; a piston yoke provided on the cylinder tube and connected to the piston via the slit; The piston and the piston yoke are provided by providing first and second end covers at both ends of a tube, and alternately supplying fluid to each pressure action chamber from first and second supply / discharge ports provided in each end cover. In the fluid pressure cylinder to move along the longitudinal direction of the storage space,
The first supply / discharge port is connected to one pressure action chamber on the opposite side to the port via at least two or more of the through holes, and the second supply / discharge port is connected to the other pressure action chamber. A rodless cylinder characterized in that: According to this configuration, the moving speed of the piston and the piston yoke can be increased.

(3) In the above (2), the first end cover has a branch passage for connecting the first supply / discharge port to at least two or more of the through holes, and the second supply / discharge port. And a communication passage that directly communicates with the piston housing space. According to this configuration, the operability of the rodless cylinder is improved because the effective cross-sectional area of the flow path is increased.

(4) In the above (2) or (3),
A rodless cylinder in which the second end cover is provided with a plurality of fluid passages for communicating all the through holes with the piston accommodation spaces. According to this configuration, the operability of the rodless cylinder is further improved because the effective cross-sectional area of the flow path is increased.

(5) The rodless cylinder according to any one of (1) to (4), wherein the two supply / discharge ports are open on the same surface. According to this configuration, since both ports are open on the same surface, centralized piping can be achieved. Therefore, the configuration is advantageous, for example, when the installation space is limited.

(6) The rodless cylinder according to (5), wherein each of the end covers is detachable. According to this configuration, the centralized piping can be performed on either one end side or the other end side of the cylinder body.

(7) The rodless cylinder according to any one of (4) to (6), wherein a part of each of the fluid passages is shared. According to this configuration, processing at the time of manufacturing the end cover is simplified.

(8) A piston accommodating space and a plurality of through holes are formed in the cylinder main body and extend along the longitudinal direction thereof, and the accommodating space is divided into a pair of pressure action chambers by a piston provided therein. A rod is protruded from one side of a piston, and fluid is alternately supplied to each pressure action chamber from first and second supply / discharge ports provided at an end of the cylinder body, whereby the rod is moved from the cylinder body. In the hydraulic cylinder adapted to be retracted, the first
A supply / discharge port is communicated with one of the pressure action chambers on the opposite side to the port through at least two or more of the through holes, and the second supply / discharge port is communicated with the other pressure action chamber. And a hydraulic cylinder. According to this configuration, the moving speed of the piston and the rod can be increased.

(9) The end cover for a fluid pressure cylinder according to any one of claims 1 to 3, wherein the two supply / discharge ports are opened on the same surface. According to this configuration, since both ports are open on the same surface, centralized piping can be achieved. Therefore, the configuration is advantageous, for example, when the installation space is limited.

(10) In claim 3 or (9),
A rodless cylinder in which a part of each of the fluid passages is shared. According to this configuration, processing at the time of manufacturing the end cover is simplified.

[0057]

As described in detail above, according to the first aspect of the present invention, the moving speed of the piston can be increased.

According to the second and third aspects of the present invention, since the effective cross-sectional area of the flow path can be increased, the moving speed of the piston can be increased.

[Brief description of the drawings]

1A and 1B show a first embodiment, in which FIG. 1A is a plan sectional view of a rodless cylinder, and FIG. 1B is a side sectional view of the same cylinder.

FIG. 2 is a cross-sectional plan view of a rodless cylinder having a concentrated pipe on the opposite side of FIG. 1 (a).

3A and 3B show a second embodiment, in which FIG. 3A is a plan sectional view of a rodless cylinder, FIG. 3B is a side sectional view of the cylinder,
(C) is a front sectional view of the cylinder.

4A and 4B show a conventional technique, in which FIG. 4A is a plan sectional view of a rodless cylinder, and FIG. 4B is a side sectional view of the same cylinder.

FIG. 5 is a cross-sectional plan view of a rodless cylinder in which piping is concentrated on the opposite side of FIG. 4 (a).

[Explanation of symbols]

11: rodless cylinder, 12: cylinder tube (cylinder main body), 12b: space (piston accommodation space), 14: piston, 16a, 16b: through hole, 19
... left pressure action chamber, 20 ... right pressure action chamber, 21, 22
... End cover (cylinder body), 23 ... First supply / discharge port, 24 ... Second supply / discharge port, 25 ... Branch passage, 27 ... Communication passage, 30a, 30b ... Fluid passage, 41 ... Hydraulic cylinder, 42 ... Cylinder Tube (cylinder body), 42b
... space (piston accommodation space), 43 ... head cover (end cover, cylinder body), 44 ... rod cover (end cover, cylinder body), 46a, 46b ... through hole, 50 ... piston, 51 ... rod side pressure action chamber, 52
... head side pressure action chamber, 57 ... first supply / discharge port, 58 ...
Second supply / discharge port, 59: branch passage, 60: communication passage.

Claims (3)

[Claims] A piston accommodating space extending in a longitudinal direction of the cylinder main body and a plurality of through-holes, wherein the accommodating space is partitioned into a pair of pressure action chambers by a piston provided therein; A fluid pressure that moves the piston along the longitudinal direction of the housing space by alternately supplying fluid to each pressure action chamber from first and second supply / discharge ports provided at one end of the main body. In the cylinder, the first supply / discharge port communicates with one pressure action chamber at the other end of the cylinder body through at least two or more of the through holes, and the second supply / discharge port communicates with the other pressure action chamber. A fluid pressure cylinder characterized by being connected to a chamber. 2. A first and a second cylinder disposed at an end of a cylinder tube having a piston accommodating space and a plurality of through holes, and for supplying a fluid to the piston accommodating space.
In a fluid pressure cylinder end cover provided with a supply / discharge port, a branch passage for communicating the first supply / discharge port to at least two or more of the through holes; and a second supply / discharge port connected to the piston housing space. An end cover for a fluid pressure cylinder, comprising: a communication passage directly communicating with the end cover. 3. A first and a second housing disposed at an end of a cylinder tube having a piston housing space and a plurality of through holes, and for supplying a fluid to the piston housing space.
An end cover for a hydraulic cylinder having a supply / discharge port, comprising: a plurality of fluid passages for communicating all of the through holes with the piston housing space.