JPS6329921Y2 - - Google Patents

Description

[Detailed explanation of the invention] (1) Purpose of the invention (field of industrial application) This invention relates to a fluid cylinder operated by fluid pressure.

(Prior art and issues to be solved) Air is placed on both sides of the piston placed inside the cylinder.
Fluid cylinder devices configured to reciprocate the piston by applying fluid pressure such as oil have been well known, but in this type of device, the piston (actually, the piston is disposed integrally with the piston) is known. It is also well known that it is often necessary to reciprocate and rotate the installed piston rod (at the same time).

And the things that make it possible to do the above,
For example, Special Publication No. 46-33457, Special Publication No. 51-
It has already been proposed, as seen in Publication No. 32795.

However, in the former publication, the gear plate 2 and the rod 3 constituting the means for rotating the piston rod 3 are operated by the groove 25 and the key 24. Therefore, in order to prevent fluid leakage, the key 24 and the groove 25 are connected to the O-
It is essential that the piston be located inside (lower in the figure) than the cover plate 15 provided with the ring 16, and for this reason, assuming a cylinder of a certain length, the stroke of the piston and piston rod must be short. In other words, the disadvantage is that it is impossible to take a long stroke.

In addition, in the second latter publication mentioned above, the piston rod is formed hollow, and a spline shaft is engaged with this, and the spline shaft supports the rotation of the piston rod, but its structure is complicated. Not only does this inevitably increase the size of the device as a whole, but when the piston rod protrudes outward from the cylinder, the engagement area between the piston rod and the spline shaft decreases, which may cause strength problems. If such a problem is to be avoided, it is necessary to increase the size of the device or to reduce the stroke in order to maintain sufficient engagement between the two at all times, which is undesirable.

The present invention was developed in order to deal with this current situation, and it is possible to rotate the piston rod in a large stroke range by fully utilizing the given cylinder length with the simplest possible configuration. It is an object of the present invention to provide a fluid cylinder device having the following functions.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, in the present invention, the piston rod in the fluid cylinder is formed into a polygonal shape, and the piston rod on the side where the piston rod appears and retracts is formed into a polygonal shape. This device is characterized in that means for rotating the piston is provided on the outside of the seal member formed on the lid of the cylinder.

In this way, by arranging the piston rod rotation means outside the actual length of the cylinder and configuring the rotation means to transmit the torque to the polygonal piston rod, the cylinder can be used effectively. This makes it possible to achieve large strokes with high reliability.

(Description of an embodiment) As shown in Fig. 1, caps 2 and 3 are provided at both ends of a hollow cylindrical cylinder body 1, and a piston 4 is slidably arranged inside the caps 2 and 3, respectively. There is.

A piston rod 5 having a polygonal (square in the illustrated embodiment) cross section is integrally attached to the piston and extends outwardly through the cap 3.

The caps 2 and 3 are formed with openings A and B through which pressure fluid enters and exits, and these are connected to a fluid circuit (not shown) for introducing and discharging pressure fluid into and out of cavities on both sides of the piston. Assume that the piston 4 and the piston rod 5 are displaced in the left-right direction in the drawing.

Inside the cap 3, a bush 8 into which the piston rod 5 is loosely fitted is rotatably supported by a bearing 7, and a pinion 9 is attached to the bush.

A packing case 11 is disposed rotatably within the cap 3 on the left side of the bush 8 in the figure, close to the cylinder 1, and inside thereof,
A sealing member 11a made of an elastic material such as rubber surrounds the piston rod, and an O-ring 11b is disposed around the outer circumference of the sealing member 11a to prevent fluid from leaking from the cylinder.

A pinion 9 is fixed to the bush 8, and a second cylinder 6 extending perpendicularly to the plane of the drawing is attached to the cap 3 at a position where the pinion 9 is present.

As can be seen from FIG. 2, the cylinder 6 has a rod 12 with pistons 13a and 13b attached to both ends.
A rack 12a is formed on the rod, and this rack meshes with the pinion 9.

The cylinder 6 is formed with openings C and D that communicate with a pressure source (not shown), through which pressurized fluid is allowed to enter and exit, thereby displacing the pistons 13a, 13b and the rod 12 as a unit in the left-right direction in the drawing. do.

With this structure, by displacing the pistons 13a, 13b and therefore the rod 12 within the cylinder 6, the pinion 9 rotates, and the bush 8 rotates accordingly. The polygonal piston rod 5 inserted into the bush will rotate.

Although not shown, stroke adjustment bolts are provided on the caps 14 and 15 at both ends of the cylinder 6 to adjust the stroke of the rod 12 and therefore the piston rod 5.
The rotation angle can be controlled.

(3) Effects of the invention Since the invention has the configuration described above, when rotating the piston and piston rod of the fluid cylinder, the rotation means is a part of the fluid cylinder for reciprocating the piston. Since it is disposed externally and unrelated to the fluid cylinder, it is possible to obtain a highly reliable, long-stroke fluid cylinder device with a simple configuration without wasting the space of the original fluid cylinder.

Furthermore, since at least the necessary portion of the piston rod is formed into a polygonal shape and the piston rod itself is rotated by applying torque, a constant torque is always applied to the piston rod over its entire length. Therefore, the piston and piston rod can operate in a constant state at all times, and there is no risk of damage.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the fluid cylinder according to the present invention, viewed in the axial direction of the piston rod;
The figure is a sectional view showing a mechanism portion for rotating the piston rod. 1... Cylinder body, 2, 3... Cap, 4...
... Piston, 5 ... Piston rod, second cylinder body, 8 ... Bush, 9 ... Pinion, 11 ...
...packing case, 12...rod body, 12a...
Latsk.

Claims (1)

[Scope of Claim for Utility Model Registration] In a fluid cylinder in which a piston and a piston rod having a polygonal cross section are integrally attached thereto, a fluid cylinder is arranged in a cap for closing the end on the side where the piston rod protrudes and retracts. A fluid cylinder comprising a bush rotatably disposed outside the sealing member to engage with the piston rod, and means for rotating the bush engaged with a pinion fixed to the bush.