JPH094606A - Air cylinder device used in liquid - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a short air cylinder device that can be used in water for a long time. [Structure] Inside a cylinder 1, a stepped portion 6 is provided on the outer peripheral portion, and a piston 5 serving as a cylindrical portion 7 is slidably accommodated with a hollow inside on the side opposite to the rod 4. A spring 8 for automatic back is arranged on the outer periphery of the piston 5,
It is interposed between the stepped portion 6 and the end face plate 2 of the cylinder 1.
A bellows 12 is arranged in the tubular portion 7 of the piston 5 and is airtightly attached between the piston 5 and the cylinder 1. An air passage 13 for supplying and discharging compressed air for advancing the piston 5 to and from the bellows 12 is formed on the head-side end surface of the cylinder 1. An outer drainage hole 16 and an inner drainage hole 17 are provided in the end face plate 2 of the cylinder 1 and the cylindrical portion 7 of the piston 5, respectively, so that water can freely flow in and out of the cylinder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cylinder device which can be used in liquid for a long term operation.

[0002]

2. Description of the Related Art FIG. 3 shows an outline of a single-acting type air cylinder device as an example of a conventional fluid cylinder device, in which a piston c with a rod b is slidably housed in a cylinder a. The rod b of the piston c is made to penetrate the opening d of the end surface of the cylinder a on the rod side, and the air pipe e is connected to the head side of the cylinder a to form the air reservoir f on the head side of the piston c. A spring g for automatic backing of the piston c is provided around the rod b between the cylinder a and the piston c, and the air pipe e
By injecting compressed air into the air reservoir f through the air reservoir f, the piston c is moved forward and extended while compressing the automatic back spring g, and the air pipe e
The compressed air injected into the air reservoir f is discharged to the outside through the spring g for the automatic back.
The piston c is retracted and contracted by the elastic force of.

[0003]

However, when the single-acting type air cylinder device as described above is used in a liquid, for example, in water, as shown by a chain double-dashed line in the figure,
Used in water by providing a seal ring h on the inner peripheral surface of the opening d provided on the rod-side end surface of the cylinder a so as to be slidable with the rod b, and waterproofing the inside of the cylinder a. However, in practice, it is very difficult to completely waterproof the cylinder a, and when the air cylinder device subjected to such waterproofing is used in water for a long period of time, However, it is impossible to prevent water from accumulating in the air pool f and the air pipe e in the cylinder a and hindering the cylinder stroke, and the water is not collected in the air pool f and the air pipe e in the cylinder a. It may be possible to use water as the working fluid of the cylinder instead of the compressed air from the beginning to prevent any trouble in the cylinder stroke even if the water is accumulated. Peripherals such as a pump for injecting into the inner becomes very expensive compared with the case of using air, there is a problem that. Further, the automatic back spring g is arranged on the outer periphery of the rod b so as to intervene between the cylinder a and the piston c. Therefore, the entire length of the device itself becomes long, and the height of the device is low. There is also a problem that the stroke length of the cylinder must be shortened when used in a narrow space.

Therefore, the present invention is intended to provide an air cylinder device which can be used in a liquid for a long period of time and has a short total length.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention fixes a rod at its central portion inside a cylinder having an end face plate through which a rod of a piston penetrates and which has an opposite end. Except for the end on the rod fixing side, the diameter of the outer peripheral portion is reduced to provide a stepped portion, and the inside of the non-rod fixing side is made hollow to form a cylindrical piston that is slidably accommodated. A spring for automatic backing arranged on the outer peripheral portion of the piston is interposed between the end face plate of the cylinder and the outer peripheral stepped portion of the piston, and a bellows arranged inside the cylindrical portion of the piston is mounted on the piston and the cylinder. And a liquid passage hole for communicating air between the inside and outside of the cylinder to the end face plate of the cylinder. Cylindrical piston The liquid discharge hole for communicating the inside and outside on the side walls of the made respectively provided configuration.

Further, a piston having a rod fixed to a central portion is slidably accommodated in a cylinder having an end face plate having a piston rod penetrating at one end, and the piston and the end face plate of the cylinder are connected to each other. Between the inner and outer bellows having different diameters with the rod as the center, and each bellows is airtightly attached to the end face plate of the cylinder and the piston. The bellows placed between the two are airtightly attached to the end face of the piston and the head side of the cylinder. A fluid drain that connects the inside of the bellows on the rod side of the cylinder to the outside of the cylinder On the end face plate, and on the cylinder side, there are provided liquid drain holes for communicating the outside of the outside bellows arranged on the rod side of the cylinder and the outside of the bellows arranged on the head side of the cylinder with the outside of the cylinder. You can also

[0007]

When compressed air is injected into the bellows when the air cylinder device is contracting, the piston slides while compressing the spring for automatic back by the pressure of the compressed air, and the air cylinder device expands. ,on the other hand,
When the compressed air in the bellows is discharged to the outside while the air cylinder device is expanded, the elastic force of the spring for the automatic back causes the air cylinder device to contract, but at this time, the cylinder head side The bellows is airtightly attached between the cylinder and the piston, and liquid is allowed to flow in and out of the cylinder by providing liquid drain holes in the end face plate of the cylinder and the cylindrical portion of the piston. It is possible to prevent liquid from entering the inside of the cylinder and prevent any trouble in the cylinder stroke.In addition, the spring for automatic back is arranged on the outer peripheral part of the piston to shorten the total length of the device itself. Can be

Further, inner and outer bellows are airtightly mounted between the rod-side end surface of the cylinder and the piston, and compressed air for contracting the cylinder is supplied between the inner and outer bellows which are doubly arranged. By doing so, it is possible to make it a double-acting type, to eliminate the need for a spring for automatic back, and to operate it by supplying and discharging compressed air.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1A and 1B show an embodiment in which a single-acting type air cylinder device is used in water as a liquid as an example of the present invention, and an opening is formed so as to penetrate a rod of a piston. Inside the cylinder 1 having the end face plate 2 provided with the portion 3 at one end, the diameter of the outer peripheral portion is required except for the end portion opposite to the side where the rod 4 is fixed and the rod 4 is fixed at the central portion. The amount of the rod 4 is reduced and the stepped portion 6 is provided.
A piston 5 formed by forming a cylindrical portion 7 with a hollow inside on the side opposite to the side where the is fixed, so that the rod 4 of the piston 5 can be inserted into and removed from the opening 3 of the end face plate 2. A spring 8 for automatic backing of the piston 5, which is slidably accommodated and is arranged on the outer peripheral portion of the piston 5 by utilizing a gap between the outer peripheral surface of the cylindrical portion 7 of the piston 5 and the inner peripheral surface of the cylinder 1. To
It is arranged to be interposed between the end face plate 2 of the cylinder 1 and the stepped portion 6 of the piston 5. In addition, a disk-shaped piston side bellows mounting plate 9 is fixed in the tubular portion 7 of the piston 5, and the head side end face in the cylinder 1 has a diameter slightly smaller than the inner diameter of the tubular portion 7 of the piston 5. The convex cylinder-side bellows mounting plate 10 is fixed via an O-ring 11 for air seal, and a bellows of a required size is provided between the piston-side bellows mounting plate 9 and the cylinder-side bellows mounting plate 10. 12 is airtightly installed, and an air flow path 13 for supplying / discharging compressed air into / from the bellows 12 is passed from the central part of the cylinder side bellows mounting plate 10 to the head side end part and the side wall part of the cylinder 1. The bellows 12 and the piston 12 are guided to a plurality of air injecting / exhausting ports 14 respectively provided on the peripheral wall of the cylinder 1 and the end surface on the rod side. The down side and watertight air reservoir 15 surrounded by a bellows mounting plate 9 and 10 of the cylinder side so as to define form. Further, the end plate 2 of the cylinder 1 is provided with a plurality of drainage holes 16 for communicating the inside and outside of the cylinder 1 with a required space in the circumferential direction, and the piston 5
A plurality of water drain holes 17 for allowing water to freely flow inside the cylinder 1 are provided on the peripheral wall of the cylindrical portion 7 at appropriate circumferential positions.

The plurality of air inlet / outlet ports 14 are provided with an air pipe 18 depending on the usage state of the air cylinder device.
Air pipe 1
The air inlet / outlet port 14 to which 8 is not connected is closed by a blind lid 19 wrapped with a sealing tape.

When compressed air is injected from the air pipe 18 into the air reservoir 15 through the air flow path 13 in a state where the air cylinder device is contracted as shown in FIG. Due to the pressure, the piston 5 moves forward while compressing the spring 8 for automatic back, and extends as shown in FIG. 1B. At this time, the water accumulated on the rod side of the piston 5 in the cylinder 1 Flows into the periphery of the bellows 12 through the water drain hole 17 as the piston 5 moves forward, or the water drain hole 1
It is discharged to the outside of the cylinder 1 through the gap between the rod 6 and the opening 3 of the end face plate 2 and the rod 4. On the other hand, when the compressed air injected into the air reservoir 15 is discharged from the air flow path 13 to the outside through the air pipe 18 in a state where the air cylinder device is extended as shown in FIG. The elastic force of the automatic back spring 8 causes the piston 5 to retract and contract as shown in FIG. 1 (a).
As the water moves backward, water around the bellows 12 flows out of the piston 5 through the water drain hole 17, and external water flows into the cylinder 1 through the water drain hole 16.

As described above, in the present invention, water can freely flow in and out of the cylinder 1 as the air cylinder device expands and contracts, and the bellows 12 and the piston side and cylinder side bellows are attached. Since the air reservoir 15 is formed in a watertight manner by the use plates 9 and 10, it is possible to completely prevent water from entering the air reservoir 15 and the air pipe 18 and prevent any trouble in the cylinder stroke. It can be used in water for a long time.

Furthermore, since the spring 8 for automatic back is arranged on the outer periphery of the cylindrical portion 7 of the piston 5 and the piston 5 and the spring 8 are arranged in parallel, the total length of the air cylinder device itself is increased. The length of the air cylinder device can be shortened and the stroke length of the air cylinder device can be sufficiently lengthened even when it is used in a narrow place of high and low width.

Next, FIGS. 2A and 2B show another embodiment of the present invention in which a double-acting type air cylinder device is used in water as a liquid, and a piston rod is provided at one end. A disc-shaped piston 5'having a rod 4 fixed at the center is slidably housed in a cylinder 1 having an end plate 2 having an opening 3 through which the piston 5'is Bellows 12 between the head side end surface of cylinder 1
And one end of the bellows 12 is airtightly mounted through the bellows mounting plate 9 on the piston side,
The other end is airtightly attached to the head-side end surface of the cylinder 1 via a cylinder-side bellows mounting plate 10 and an O-ring 11, and compressed air is supplied to and discharged from the bellows 12 through an air flow path 13 provided in the head-side end surface. In addition, inner and outer bellows 25 and 26 having different diameters are arranged around the rod 4 on the rod side of the piston 5 and near the outer periphery, and one end of each is attached to the inner and outer bellows mounting rings 20 and 2.
1. Double-fixed to the piston 5 via the O-ring 22 for air seal, and the other end is doubled to the end face plate of the cylinder 1 via the inner and outer bellows mounting rings 23 and 24 and the O-ring 22. The air passage 27 on the rod side, which is fixed and is provided on the end face plate 2, is opened and communicated with an air reservoir 30 defined between the inner bellows 25 and the outer bellows 26. The flow path 27 is guided to the rod side air inlet / outlet port 28 provided on the peripheral wall of the cylinder 1, and air is supplied / discharged from the rod side air pipe 29 connected to the air inlet / outlet port 28. On the other hand, in the air reservoir 15 formed in the bellows 12 on the head side,
As in the case of FIG. 1, the air flow paths 13 are opened to communicate with each other so that air is supplied and discharged from the air pipes 18. Further, the inner peripheral surface of the opening 3 of the end face plate 2 is provided with a plurality of air gaps at appropriate intervals. Is provided to connect the inside of the inner bellows 25 and the outside of the cylinder 1 to each other, and a plurality of peripheral side walls of the cylinder 1 are also provided at the rod-side and head-side end positions at predetermined intervals in the circumferential direction. The rod-side drainage hole 32 and the head-side drainage hole 33 are provided so that the outside of the outer bellows 26 and the outside of the head-side bellows 12 communicate with the outside of the cylinder 1.

When the air cylinder device is contracted as shown in FIG. 2A, the air passage 1 on the head side is provided.
3, compressed air is injected into the air reservoir 15 in the bellows 12 on the head side, and the bellows 25 and 26 on the rod side are provided.
Compressed air in the air reservoir 30 between the air passages 27 on the rod side
And when it is discharged to the outside through the air pipe 29, the piston 5'is lifted in the figure to be extended by the pressure of the compressed air injected into the bellows 12 on the head side. At this time, the inside of the bellows 25 on the rod side and the bellows 26
The water accumulated on the outside of the cylinder is discharged to the outside of the cylinder 1 through the water drain holes 31 and 32, and the water flows into the periphery of the bellows 12 on the head side through the water drain hole 33. On the other hand, when the air cylinder device is extended as shown in FIG. 2B, compressed air is injected between the bellows 25 and 26 on the rod side from the air passage 27 on the rod side and the head side When the compressed air in the bellows 12 is discharged through the air passage 13 and the air pipe 18 on the head side, the contraction operation is performed by the reverse operation to the above case. Therefore, (a) in FIG.
Also in the embodiment shown in (b), water can freely flow in and out of the cylinder 1, and the bellows 1 on the head side is also provided.
2 air bellows 15 and inner and outer bellows 2 on the rod side
Since the air reservoir 30 formed between 5 and 26 is watertightly partitioned and formed, the air reservoirs 15 and 30 and the air pipes 18 and 29 are formed.
It is possible to completely prevent the ingress of water into the inside, and it is possible to continue using it in water for a long time without any trouble in the cylinder stroke.
Spring 8 for automatic back used in the embodiment of (b)
The cylinder can be expanded and contracted only by compressed air without the need for.

In each of the above embodiments, the case where the air cylinder device is used in water is shown. However, if it is a liquid, it is not limited to being used in water, but can be used in the same manner in oil. What is possible, and also for mounting the bellows 12, 25 and 26 between the inner surface of the cylinder 1 and the pistons 5, 5 ', the bellows mounting plates 9 and 10 and the bellows mounting rings 20, 21, and 2.
3 and 24 are used, the plates 9 and 10 and the rings 20, 21, 23 and 24 can be omitted. In short, the bellows 12, 25 and 26 are used to replace the pistons 5 and 5 '. Watertight air reservoirs 15, 3 below and above
It is only necessary to form 0 in the form of partitions, and it goes without saying that the present invention can be variously modified without departing from the scope of the invention.

[0018]

As described above, according to the air cylinder device of the present invention used in a liquid, a stepped portion is provided in the outer peripheral portion of the cylinder, and a piston having a hollow inside is slidable. It is housed and a spring for automatic back is arranged on the outer peripheral part of the piston, and the bellows arranged in the cylindrical part of the piston is airtightly attached between the piston and the cylinder, and is fed into and discharged from the bellows. The compressed air and the elastic force of the spring for the automatic back allow the air cylinder device to expand and contract, and the drainage holes are provided in the end face plate of the cylinder and the side wall of the cylindrical portion of the piston to allow the inside of the bellows to move. Except for the fact that the liquid can freely flow in and out of the cylinder, it is possible to prevent any trouble in the cylinder stroke and to keep it in the liquid for a long time. It can be used for a long time, and since the device itself can be shortened and the cylinder stroke length can be made sufficiently long even when used in narrow places with high and low widths, air in liquid can be The use of the cylinder device can be promoted, and the inner and outer double bellows are airtightly attached between the rod-side end surface of the cylinder and the piston to expand and contract the cylinder between the double inner and outer bellows. When compressed air to be operated is supplied and discharged, and liquid can be freely flowed in and out of the cylinder by the liquid drain holes provided in the peripheral wall of the cylinder.
In addition to being able to use the air cylinder device in liquid for a long period of time, the spring for automatic back can be eliminated, and the cylinder can be expanded and contracted only by supplying and discharging compressed air. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 shows a single-acting type air cylinder device as an example of an air cylinder device used in a liquid of the present invention, in which (a) shows a contracted state of the air cylinder device and (b) shows the air cylinder device. It is sectional drawing which respectively shows the extended state.

FIG. 2 shows a double-acting type as another embodiment of the present invention, in which (a) shows a state in which the air cylinder device is contracted,
(B) is a sectional view showing a state where the air cylinder device is extended.

FIG. 3 is a schematic view showing an example of a single-acting air cylinder device.

[Explanation of symbols]

 1 Cylinder 2 End Face Plate 4 Rod 5, 5'Piston 6 Stepped Part 7 Cylindrical Part 8 Spring 12 Bellows 13 Air Flow Path 16 Water Draining Hole (Liquid Draining Hole) 17 Water Draining Hole (Liquid Draining Hole) 25 Inner Bellows 26 Outer Bellows 27 Air Flow Path 31, 32, 33 Water Draining Hole (Liquid Draining Hole)

Claims (2)

[Claims] Claim: What is claimed is: 1. A cylinder having an end plate through which a rod of a piston penetrates at one end, wherein the rod is fixed at the center and the diameter of the outer peripheral portion is reduced except for the end on the side opposite to the rod fixing side. A piston, which is provided with a stepped portion and which has a hollow cylindrical shape on the side opposite to the fixed side of the rod, is slidably accommodated, and a spring for automatic backing arranged on the outer peripheral portion of the piston is used for the cylinder. The bellows, which is interposed between the end face plate of the piston and the outer peripheral stepped portion of the piston and is arranged in the cylindrical portion of the piston, is airtightly mounted between the piston and the cylinder to prevent air from entering the bellows. The cylinder is provided with a flow path for supplying and discharging, and further, a liquid drain hole for communicating the inside and outside of the cylinder with the end face plate of the cylinder, and a liquid drain hole for communicating with the inside and outside of the side wall of the cylindrical portion of the piston. Please provide each An air cylinder device used in a liquid, characterized in that 2. A piston having a rod fixed to a central portion is slidably housed in a cylinder having an end face plate having a piston rod penetrating at one end, and the piston and the end face plate of the cylinder are provided. Between the inner and outer bellows having different diameters with the rod as the center, and each bellows is airtightly attached to the end face plate of the cylinder and the piston. The bellows placed between the two are airtightly attached to the end face of the piston and the head side of the cylinder. The cylinder is provided with a flow path for performing the above, and a drain hole for communicating the inside of the inner bellows arranged on the rod side of the cylinder with the outside of the cylinder is provided. On the end face plate, and also on the cylinder side portion, there are provided liquid drainage holes for communicating the outside of the outer bellows arranged on the rod side of the cylinder and the outside of the bellows arranged on the head side of the cylinder with the outside of the cylinder. An air cylinder device used in a characteristic liquid.