JPH0949507A - Fluid pressure cylinder device - Google Patents

Abstract

(57) [PROBLEMS] To provide a low-cost fluid pressure cylinder device capable of switching the piston speed in the middle of a stroke with a simple structure without providing a sensor, a pilot valve, or the like outside. To do. SOLUTION: On the outer peripheral surface of a piston 12, packings 21 and 22 or packings 22 and 22 are provided at two axial positions.
Partition chambers 35 and 36 partitioned by 23 are provided, and the partition chamber is the throttle hole 3 provided in the piston 12.
9 and 40 communicate with one of the pressure chambers 31 and 32, and ports 33 and 34 for supplying and discharging pressure fluid to and from the pressure chambers 31 and 32 are provided in the cylinder tube 11 depending on the stroke position of the piston 12. From the peripheral surface to the one pressure chamber 3
1, 32 or the partition chambers 35, 36 are provided so as to open.

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 device capable of changing speed during a stroke.

[0002]

2. Description of the Related Art Conventionally, in order to switch the piston speed of a fluid pressure cylinder device in the middle of a stroke, the stroke position of the piston is detected by an externally mounted sensor or pilot valve, and the main valve is switched by the detection signal. The flow rate is controlled.

In order to reduce the speed at the stroke end, a cushion boss is provided so as to project from the end face of the piston, and the boss is fitted into a cushion hole provided in the cylinder cover. Fluid pressure cylinder device is used.

[0004]

However, when a sensor or a pilot valve is used, the number of components becomes large, the overall structure becomes complicated and the cost becomes high, and many adjustments and maintenances are required. It takes time.

Further, when a fluid pressure cylinder device with a cushion is used, it is necessary to provide a boss for a cushion and to machine a cushion hole to be fitted therein, which increases the number of parts and complicates the structure. I cannot escape.

The present invention has been made in view of the above problems, and is a low-cost fluid pressure that can change the piston speed in the middle of a stroke with a simple structure without providing a sensor or a pilot valve outside. An object is to provide a cylinder device.

[0007]

According to a first aspect of the present invention, there is provided a cylinder tube, a piston which slides in the cylinder tube and partitions the cylinder tube into left and right pressure chambers, and A fluid pressure cylinder device comprising a rod-side cover and a head-side cover for closing both ends, wherein a partition chamber partitioned by packings provided at two axial positions is provided on an outer peripheral surface of the piston. The partition chamber is provided in communication with one of the pressure chambers through a throttle hole provided in the piston, and a port for supplying / discharging pressure fluid to / from the one pressure chamber has a stroke position of the piston. According to the above, it is provided so as to open from the inner peripheral surface of the cylinder tube to either the one pressure chamber or the partition chamber.

In the apparatus according to the second aspect of the present invention, the piston is provided with a check valve connected in parallel with the throttle hole. For example, in FIG. 1, the right port 34
When the compressed air is supplied from the port 33 and the compressed air is exhausted from the port 33 on the left side, the compressed air supplied from the port 34 flows into the partition chamber 36, and from the partition chamber 36 to the pressure chamber 32 via the throttle hole 40. Inflow. As a result, pressure is generated in the pressure chamber 32 and the piston 12 moves leftward in the drawing. At this time, that is, while the compressed air from the port 34 passes through the throttle hole 40, the flow rate is throttled by the throttle hole 40, and the piston 12 moves at a low speed.

When the piston 12 moves, the packing 23 eventually passes through the opening of the port 34, and the port 34 directly communicates with the pressure chamber 32. Then, the compressed air from the port 34 flows into the pressure chamber 32 without passing through the throttle hole 40, so a large amount of compressed air flows into the pressure chamber 32, and the piston 12 moves at high speed. That is, the moving speed of the piston 12 is switched from low speed to high speed before and after the packing 23 passes through the opening of the port 34 by the movement of the piston 12.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional front view of a pneumatic cylinder device 1 according to the present invention, FIG. 2 is a left side view of the pneumatic cylinder device 1, and FIG. FIG.

The pneumatic cylinder device 1 slides on the cylinder tube 11, the inner peripheral surface 11a of the cylinder tube 11, and the left and right pressure chambers 3 inside the cylinder tube 11.
A piston 12, which is partitioned into 1 and 32, a piston rod 13 which is connected to the piston 12, a rod side cover 14 which closes both ends of the cylinder tube 11, and a head side cover 15.
Etc. The piston rod 13 penetrates the rod-side cover 14 airtightly and slidably and projects to the outside.

The cylinder tube 11 is made by cutting an extruded material of aluminum alloy into a length dimension corresponding to the stroke length. The cylinder tube 11 has a rectangular outer shape and a circular inner surface 11a. A part of the cylinder tube 11 in the circumferential direction is thick,
Ports 33 and 34 for supplying and discharging compressed air are
It is provided at a position distant from the inner end face position of each cover 14, 15 toward the center in the axial direction. Ports 33,34
The diameter of the opening to the inner peripheral surface 11a of the
The width is smaller than or substantially the same as the width of No. 3.

The piston 12 is formed of aluminum alloy or the like into a cylindrical shape. On the outer peripheral surface of the piston 12, peripheral grooves for packing are formed at both ends and a central portion, respectively, and packings 21, 22 and 23 are attached to the peripheral grooves, respectively, and between the inner peripheral surface 11a of the cylinder tube 11 and the inner peripheral surface 11a. Is sealed. On the outer peripheral surface of the piston 12, an outer diameter between the packings 21 and 22 and between the packings 22 and 23 is slightly smaller than the inner diameter of the inner peripheral surface 11a of the cylinder tube 11, and a partition chamber is provided between them. 35 and 36 are formed.

Deep grooves 37 and 38 are formed in the partition chambers 35 and 36 near the packings 21 and 23, and the pistons 12 are provided in the grooves 37 and 38, respectively.
2. Throttle holes 39 and 40 are formed so as to penetrate from the respective end faces. The partition chamber 3 is formed by the throttle holes 39 and 40.
5, 36 communicate with the pressure chamber 31 or 32.

The ports 33 and 34 described above are positioned so that when the piston 12 reaches the stroke end positions on the respective sides, the ports 33 and 34 open in positions close to the central packing 22 in the respective partition chambers 35 and 36. It is provided.

Gum pads 24 and 25 for cushions are attached to both end surfaces of the piston 12.
The piston 12 is fixed to the piston rod 13 with a screw 26.

Next, the operation of the above pneumatic cylinder device 1 will be described. In the state shown in FIG. 1, when a valve (not shown) is switched so that the compressed air is supplied from the right port 34 and the compressed air is discharged from the left port 33, the compressed air supplied from the port 34 is separated from the partition chamber 36.
Flow into the pressure chamber 32 from the partition chamber 36 via the circumferential groove 38 and the throttle hole 40. As a result, the pressure chamber 32
A pressure is generated on the piston 12 and the piston 12 moves to the left in the figure.
At this time, that is, the compressed air from the port 34
While passing 0, the flow rate is throttled by the throttle hole 40,
The piston 12 moves at a low speed.

When the piston 12 moves, the packing 23 eventually passes through the opening of the port 34, and the port 34 directly communicates with the pressure chamber 32. Then, the compressed air from the port 34 flows into the pressure chamber 32 without passing through the throttle hole 40, so a large amount of compressed air flows into the pressure chamber 32, and the piston 12 moves at high speed. That is, the moving speed of the piston 12 is switched from low speed to high speed before and after the packing 23 passes through the opening of the port 34 by the movement of the piston 12.

The piston 12 moves to the left, and the packing 2
When 1 passes through the opening of the port 33, the back pressure in the pressure chamber 31, which has been directly exhausted from the port 33, becomes
It passes through the partition hole 35 and the circumferential groove 37, passes through the partition chamber 35, and reaches the port 33, and is throttled by the throttle hole 39 on the way. As a result, the displacement is reduced and the back pressure is increased, and the moving speed of the piston 12 is switched from high speed to low speed.

On the contrary to the above, when compressed air is supplied from the port 33 to move the piston 12 to the right in the figure, the same operation as described above switches between low speed / high speed / low speed.

According to the pneumatic cylinder device 1, the piston speed can be switched in the middle of the stroke with a simple structure without providing a sensor or a pilot valve outside. Moreover, the structure is simple and the cost is low.
The speed at low speed is adjusted by the diameter and length of the throttle holes 39, 40.

The clearance (distance in the radial direction) between the partition chambers 35 and 36 is several tenths of mm to 1 mm.
Degree is fine. Processing for providing the partition chambers 35 and 36 is extremely easy. Although the partition chambers 35 and 36 are formed over the entire area of the outer peripheral surface of the piston 12 in the circumferential direction, a plurality of axial grooves may be provided in the circumferential direction to form the partition chamber. Instead of the circumferential grooves 37, 38, radial holes may be used. Inner peripheral surface 11 of piston 12 and cylinder tube 11
A wear ring made of synthetic resin or the like may be provided in the vicinity of the packings 21, 23 on the outer peripheral surface of the piston 12 in order to slide with a.

Next, another embodiment of the pneumatic cylinder device 1 will be described. Pneumatic cylinder device 1 of another embodiment
As for a, a check valve having a known structure is provided in the piston 12 so as to be connected in parallel with the throttle holes 39 and 40. Due to the free flow of the check valve, the compressed air flows without being throttled and the piston 12 moves at high speed. By selecting the direction of free flow of the check valve, it is possible to select which of the rising speed (starting time) and the stopping time of the piston 12 is set to be high speed.

The pneumatic cylinder device 1b of another embodiment is
Only one partition chamber 36 is provided, and the piston 12 does not exist in the partition chamber 35 portion. The port 33 is provided at an end face position (AA position in FIG. 1) inside the rod side cover 14 in the cylinder tube 11. The speed of the pneumatic cylinder device 1b switches from low speed to high speed when moving leftward in FIG. 1, and switches from high speed to low speed when moving rightward.

The structure, shape, size, material, etc. of the whole or each part of the pneumatic cylinder devices 1, 1a, 1b can be appropriately changed in accordance with the gist of the present invention. In addition to the pneumatic cylinder device, it can be applied to a hydraulic cylinder device, a hydraulic cylinder device, and the like.

[0026]

According to the first aspect of the present invention, the piston speed can be switched in the middle of the stroke with a simple structure and at low cost without providing a sensor, a pilot valve or the like outside.

According to the second aspect of the invention, the speed switching state can be changed depending on the moving direction of the piston.

[Brief description of drawings]

FIG. 1 is a sectional front view of a pneumatic cylinder device according to the present invention.

FIG. 2 is a left side view of the pneumatic cylinder device.

FIG. 3 is a cross-sectional view showing an enlarged main part of the pneumatic cylinder device.

[Explanation of symbols]

 1 Pneumatic Cylinder Device (Fluid Cylinder Device) 11 Cylinder Tube 12 Piston 13 Piston Rod 14 Rod Side Cover 15 Head Side Cover 21,22,23 Packing 31,32 Pressure Chamber 33,34 Port 35,36 Partition Chamber 39,40 Throttle hole

Claims (2)

[Claims] 1. A cylinder tube, a piston that slides in the cylinder tube and partitions the inside of the cylinder tube into left and right pressure chambers, and a rod side cover and a head side cover that close both ends of the cylinder tube. A fluid pressure cylinder device having, wherein a partition chamber partitioned by packings provided at two axial positions is provided on an outer peripheral surface of the piston, and the partition chamber is provided on the piston. The pressure chamber communicates with one of the pressure chambers by a throttle hole, and a port for supplying and discharging a pressure fluid to and from the one pressure chamber,
The fluid pressure cylinder device is provided so as to open from the inner peripheral surface of the cylinder tube to either the one pressure chamber or the partition chamber depending on the stroke position of the piston. 2. The fluid pressure cylinder device according to claim 1, wherein the piston is provided with a check valve connected in parallel with the throttle hole.