JPH051004U - Fluid pressure cylinder - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fluid pressure cylinder having a function of automatically correcting a misalignment between a piston rod and a moving direction of a driven body. [Structure] An opening 10 for loosely inserting a rod 9 is formed in the front surface of the piston 7, and a mounting groove 11 is formed in the inner periphery thereof, and an annular groove having a spherical concave surface 15 formed in the inner periphery is formed therein. A rod holder 14 is fitted so as to move freely in the direction perpendicular to the axial direction of the piston 7, and a spherical head 16 provided at the rear end of the rod 9 is fitted in its spherical concave surface 15 so that it can swing freely. The center hole 18 of the rod cover 5 is formed to have a size in which the rod 9 is loosely inserted, and the packing groove 21 formed in the inner periphery of the center hole 18 has a packing pad holder 21 having a rod packing 23 mounted on the inner circumference thereof in a direction perpendicular to the axial direction. It is fitted so that it can move freely. The rod 9 moves in the radial direction and the rod cover 5 moves.
By performing a swinging motion around the center hole 18 of the above, the centering with the moving direction of the driven body is performed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid pressure cylinder that is used by connecting the tip of a piston rod to a driven body that is free to move along a certain guide such as a slide table, and in particular, the moving direction of the driven body and the axis of the piston rod do not match. In some cases, the present invention relates to a fluid pressure cylinder having a function of correcting them.

[0002]

[Problems to be solved by conventional techniques and devices]

 In this type of fluid pressure cylinder, it is extremely difficult to attach the piston rod so that the axis of the rod is completely aligned with the axis of movement of the driven body. It is well known that there are problems such as the occurrence of the above-mentioned problems, and the presence of these causes an unnecessary load to be applied to the guide of the driven body, which hinders smooth operation and causes deformation of the cylinder.

For this reason, conventionally, means for coupling via a universal joint such as a ball joint was taken, but the overall length of the device is increased and the overall size of the device is increased, and the number of steps for assembling the joint is increased. As a result, the burden of assembly cost becomes heavy.

As one solution, as described in Japanese Utility Model Publication No. 57-48965, there has been proposed a structure in which a piston rod is connected to a piston so that it can be swung freely within the center hole of the rod cover. This is effective for correcting the angular deviation between the axes of the driven body and the rod, but it is not possible to correct the positional deviation due to the eccentricity of both axes. I got it.

[0005]

[Means for Solving the Problems]

 The fluid pressure cylinder of the present invention has been devised in view of the above points, in which the rod is movable in the direction perpendicular to the axis of the tube and is swingable with respect to the axis. It is configured so as to protrude from and to be inserted into the center hole of the rod cover.

[0006]

[Action]

 If there is a positional deviation in which the axis of the rod and the moving axis of the driven body are eccentric, the rod moves in parallel in the tube and the axis of the rod coincides with the moving axis of the driven body. On the other hand, if there is an angular misalignment between the two axes, the rod will oscillate and match that axis with the moving axis of the driven body. Further, even when there is a deviation between both, the above-described parallel movement and swing of the rod are combined to achieve perfect alignment of both axes.

[0007]

【Example】

 Various embodiments in which the present invention is applied to an air cylinder will be described below with reference to the accompanying drawings.

1 to 3 show a first embodiment. In the figure, reference numeral 1 denotes a cylinder tube having a head cover 2 provided with a supply / discharge port 3 for pressurized air attached to one end thereof, and a supply / discharge port 6 described later in detail at the other end. A rod cover 5 is provided, and a piston 7 is fitted in the tube 1 in an airtight and slidable manner.

At the center of the front surface of the piston 7, there is formed an opening 10 through which the outer circumference of the piston rod 9 is loosely inserted with a certain clearance, and a circular mounting groove 11 is further formed on the inner circumference thereof. An air escape port 12 that opens to the front surface of the piston 7 is formed on the outer peripheral portion of the piston 7, and a spherical concave surface 15 is formed on the inner peripheral surface in the mounting groove 11 to divide the ring into two. The rod holder 14 is mounted so that it can move freely in the direction perpendicular to the axial direction of the piston 7 by using both side surfaces of the mounting groove 11 as guides. A spherical head 16 formed at the rear end of the piston rod 9 is fitted in the spherical concave surface 15 of the rod holder 14 so as to freely swing.

The tip of the piston rod 9 penetrates the center hole 18 of the rod cover 5 and protrudes to the outside. The center hole 18 of the rod cover 5 similarly keeps the outer circumference of the piston rod 9 constant. It is formed to have a clearance for loose insertion, and a circular fitting groove 19 is further provided around the inner periphery of the center hole 18, and the air that opens to the rear surface of the rod cover 5 is provided at the outer periphery thereof. The escape port 20 is formed.

An annular packing holder 21 is fitted in the fitting groove 19 so as to be freely movable in the direction perpendicular to the axial direction of the piston 7 by using both side surfaces of the fitting groove 19 as guides. A rod packing 23 for sealing the outer circumference of the piston rod 9 is fitted in the circumferential groove 22 formed in the above. Further, a seal ring 24 that seals between the fitting groove 19 and the outside is fitted in a circular groove that is provided around the front surface of the packing holder 21.

The first embodiment has such a structure, and its operation will be described below. The tip of the piston rod 9 of the air cylinder installed at a predetermined position is directly coupled to a not-shown driven body such as a slide table which is freely movable along a certain guide, and the supply / discharge ports 3 and 6 to the piston 7 are connected. When pressurized air is alternately supplied to and discharged from the front chamber and the rear chamber, the piston rod 9 advances and retreats and the driven body reciprocates back and forth.

At this time, as shown in FIG. 1, if the axis A of the piston rod 9 and the moving axis B of the driven body are eccentric to each other and there is a positional deviation, as shown in FIG. In the mounting groove 11 of the rod cover 5 and in the fitting groove 19 of the rod cover 5 in the fitting groove 19 of the rod cover 5, the piston rod 9 moves in parallel while moving in the radial direction by supplying and exhausting air from the escape ports 12 and 20, respectively. The axis A is aligned with the moving axis B of the driven body.

When there is an angular deviation between the two axes A and B, the spherical head 16 of the piston rod 9 swings its head within the spherical concave surface 15 of the rod holder 14 as shown in FIG. While the rod holder 14 moves in the mounting groove 11 in the radial direction, the piston rod 9 swings around the center hole 18 of the rod cover 5, and its axis A coincides with the movement axis B of the driven body.

Further, even when there is a deviation between both, the above-described parallel movement and swing of the piston rod 9 are combined so that both axes A and B are completely coincident with each other.

FIG. 4 shows a second embodiment, in which a seal on the outer circumference of the piston rod 9 and a seal between the fitting groove 19 and the outside are provided in the fitting groove 19 formed in the center hole 18 of the rod cover 5. A large-sized rod-packing 26 that functions as both of these is fitted so as to be freely movable in the radial direction, and other structures are the same as in the first embodiment.

As shown by the solid line in the figure, if there is a positional deviation between the piston rod 9 and the axes A and B of the driven body, the rod packing 26 itself will move inside the fitting groove 19 as shown by the chain line. While the piston rod 9 moves in the direction, the piston rod 9 moves in parallel to align the axes, and if there is an angular deviation, the piston rod 9 is swung in the rod packing 26 to align the axes. Acts like. There is an advantage that the structure is simpler than that of the first embodiment.

5 to 7 show still another embodiment in which the structure on the piston side is modified. In the third embodiment shown in FIG. 5, the spherical head 16 formed at the rear end of the piston rod 9 is fitted freely into the spherical concave surface 30 formed directly in the center of the front surface of the piston 7a, and A ring-shaped packing holder 32 having piston packing 33 on the outer peripheral surface and seal packing 34 on the front and rear surfaces is fitted in the fitting groove 31 formed around the outer circumference of 7a so as to be freely movable in the radial direction. The structure is such that it is tightly fitted to the inner circumference of the cylinder tube 1. That is, while the packing holder 32 moves in the fitting groove 31 in the radial direction relatively, the piston rod 9 moves horizontally along with the piston 7a, and the spherical head 16 swings its head in the spherical concave surface 30 to move the piston rod 9. 9 swings.

In the fourth embodiment shown in FIG. 6, the piston rod 9a is integrally formed on the front surface of the piston 7b, and the outer peripheral surface of the piston 7b is formed in a spherical shape and is formed on the spherical peripheral surface 36 thereof. As in the third embodiment, the piston packing 33 and the seal packing 34 are fitted in the fitting groove 31a, and the ring-shaped packing holder 32a having a spherical outer periphery is fitted so as to be freely movable in the radial direction. The structure is such that the packing holder 32a relatively moves in the fitting groove 31a in the radial direction, the piston rod 9a moves in parallel with the piston 7b, and the spherical peripheral surface 36 causes the piston 7b to move. The piston rod 9a swings due to its own swing.

In the fifth embodiment shown in FIG. 7, a piston rod 9a is also integrally provided on the piston 7c so as to project, and a large piston packing that also serves as a seal packing is provided in a fitting groove 31b formed on the outer circumference of the piston 7c. 38 in which the piston packing 38 is freely movable in the radial direction, the piston rod 9a moves in parallel with the relative movement of the piston packing 38 in the fitting groove 31b in the radial direction, and the piston packing 38 is elastic. While deforming, the piston 7c swings its head and the piston rod 9a swings.

The present invention is not limited to air cylinders, but can be widely applied to other fluid pressure cylinders such as hydraulic cylinders.

[0022]

[Effect of the device]

 As described above, according to the present invention, it is possible to automatically correct a wide range of misalignment over both the angular misalignment and the positional misalignment between the rod and the driven body axis line. As a result, it is possible to reliably prevent problems such as smooth operation being hindered or deformation of the cylinder being caused.Moreover, wide-range correction can be performed, resulting in a large installation tolerance of the fluid pressure cylinder. The installation work can be performed easily.

Moreover, since the fluid pressure cylinder itself has all of the above-described correction functions, the device can be downsized because the joint is not necessary as compared with the case where the conventional joint is used. Moreover, there is an effect that the man-hours for assembling can be reduced and the assembling cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a positional deviation correction operation.

FIG. 3 is an explanatory diagram of an operation of correcting an angular deviation.

FIG. 4 is a partially cutaway side view of the second embodiment.

FIG. 5 is a partially cutaway side view of the third embodiment.

FIG. 6 is a partially cutaway side view of the fourth embodiment.

FIG. 7 is a partially cutaway side view of the fifth embodiment.

[Explanation of symbols]

1: Cylinder tube 2: Head cover 5: Rod cover 7, 7a, 7b, 7c: Piston 9, 9a:
Piston rod 10: Opening hole 11: Mounting groove 14: Rod holder 15: Spherical concave surface 16: Spherical head portion 18:
Center hole (of rod cover 5) 19, 31, 31a, 3
1b: Fitting groove 21, 32, 32a: Packing holder
26: Rod packing 36: Spherical surface 38: Piston packing

Claims (1)

[Claims for utility model registration] 1. A piston is slidably fitted in a tube having a head cover at one end, and a rod protruding from one side of the piston is provided at the other end of the tube. In the fluid pressure cylinder, the rod is projected to the outside through the center hole of the rod cover, and the projecting end of the rod is connected to a driven body that is free to move along a certain guide. Is movable in the direction perpendicular to the axis of
A fluid pressure cylinder, which is provided so as to be swingable with respect to the axis line, projecting from the piston and inserted through the center hole of the rod cover.