JPH0140323Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid pressure cylinder that is reciprocated by fluid pressure, and more particularly to a connecting device between a piston and a piston rod in the cylinder.

Conventionally, when fixing a piston to a piston rod, as shown in FIG.
_A1 is fixed at a desired position on the rod B by a fixing ring C interposed between the divided body _A1 and the piston rod B, and the other divided body _A2 is placed facing _the divided body A1. At the same time, a plurality of bolts D are axially inserted from the other divided body a ₂ side to the one divided body side.
were screwed together, thereby connecting both the divided bodies a ₁ and a ₂ to each other and fixing them to the piston rod B at the same time. However, according to this, two divided bodies
It is necessary to make an insertion hole and a threaded hole in a ₁ and a ₂ in the axial direction for inserting and screwing the bolt D, so there is no problem if the piston diameter is relatively large, but if the piston diameter is, for example, 50 mm. It was extremely difficult to process small diameters such as those below.

This idea was made in view of the above circumstances.
It is an object of the present invention to provide a fluid pressure cylinder that can be easily manufactured even in the case of a small diameter piston.
The gist of the present invention in accordance with this purpose is that a fixing ring is fitted into a ring groove provided around a predetermined position of a piston rod by protruding from the circumferential surface of the rod, and at the same time, the fixing ring is fitted in a ring groove provided around a predetermined position of the piston rod, while the piston rod is fitted in a ring groove protruding from the circumferential surface of the rod. A piston body having a large diameter enlarged hole with a female thread formed on its inner circumferential surface and a piston rod fitting hole, and a piston body having a coaxially connected enlarged hole portion with a female thread formed on the inner circumferential surface thereof and a rotary operating tool engaging portion provided at a required portion of the outer surface. and a piston member formed on the outer peripheral surface with a male thread that engages with the female thread of the enlarged hole, and the piston member is fitted into the piston rod with its tip abutting the fixing ring, and A detent piece is inserted into a hole continuously drilled from the piston member to the piston rod, and the enlarged hole of the piston body that is fitted to the piston rod is inserted into the piston member from the side facing the piston member with the fixing ring in between. It is made by screwing and tightening.

An embodiment of the present invention will be described below with reference to FIG.

In this figure, reference numeral 1 denotes a so-called double-rod type piston rod in a fluid pressure cylinder, and a ring groove 2 having a U-shaped cross section is formed in the circumferential direction at its axial center position. A snap-type fixing ring 3 made of steel and having a radial thickness approximately twice the depth of the ring 2 is fitted. A piston 4 is composed of a piston body 5 and a piston member 6 that is engaged with the piston body 5.

The piston body 5 has a piston rod fitting hole 7 which has a diameter slightly larger than the outer diameter of the piston rod 1 and is fitted into the rod 1, and the fixing ring 3.
An enlarged hole 8 having a diameter larger than the outer diameter of the hole 8 is coaxially connected to the enlarged hole 8, and a female thread 9 is formed on the inner peripheral surface of the enlarged hole 8. are substantially the same, and an annular locking step 10 having a surface perpendicular to the axial direction is formed at the boundary between the two. Further, grooves 11, 11 for installing piston packings are formed on the outer circumferential surface of the piston body 5 at both ends in the axial direction, and a groove 12 for installing a wear ring is formed in the middle of these grooves 11, 11. A plurality of holes 13 serving as rotary operating tool engaging portions are provided on the bottom surface of the groove 12 at intervals in the circumferential direction. Note that, for example, a claw of a torque wrench is inserted into this hole 13. Furthermore, a cushion sleeve body 14 is integrally extended on the piston rod fitting hole 7 side of the piston body 5 to engage with a cushion ring (not shown) mounted on the cylinder body side. .

On the other hand, the piston member 6 is formed into a sleeve shape and has a piston rod fitting hole 15 having the same hole diameter as the piston rod fitting hole 7 of the piston body 5, and has an enlarged hole 8 in the piston body 5 on its outer peripheral surface. A male thread 16 is formed to engage with the female thread 9 of the piston member 6, and a cushion sleeve body 17 similar to the piston body side cushion sleeve body 14 described above is integrally extended from the piston member 6.

The piston rod 1 and the piston member 6 fitted therein also have a hole that communicates from the piston member 6 to the piston rod 1 when the tip of the piston member 6 is in contact with the end surface of the fixing ring 3 on the piston rod 1. A portion 18 is bored into the hole 18, and a detent piece 19 having a short cylindrical shape, for example, is inserted into the hole 18. Note that the detent piece 19 is not limited to a cylindrical shape, but may be prismatic, spherical, or the like.

20 in FIG. 1 indicates a seal packing.

To assemble the piston 4 to the piston rod 1, first, the fixed link 3 is fitted into the ring groove 2 of the piston rod 1, and then the piston member 6 is fitted into the piston rod 1 from one end thereof, and the tip of the piston member 6 is fitted. A detent piece 19 is brought into contact with one end surface of the fixing ring 3 and engaged in a hole 18 interposed between the piston member 6 and the piston rod 1.
Thereafter, the piston body 5 is fitted into the piston rod 1 through its fitting hole 7 from the side opposite to the piston member 6, and the female thread 9 of the enlarged hole 8 is screwed into the male thread 16 of the piston member 6. While tightening, the locking step 10 of the piston body 5 is brought into contact with the other end surface of the fixing ring 3, and by finally tightening the piston body 5, the tip of the piston member 6 and the piston body 5 are locked. The stepped portion 10 is pressed against both end surfaces of the fixing ring 3, thereby integrally connecting the piston body 5 and the piston member 6 with each other, and at the same time, integrally fixing them to the piston rod 1. When tightening the piston body 5, a locking pawl (not shown) of a rotary operating tool, such as a torque wrench, is engaged with the hole 13 serving as a rotating operating tool engaging portion, and the wrench is rotated. It is sufficient to rotate the piston body 5 while rotating the piston member 6, and the piston member 6 is
Since it is fixed to the piston rod 1 by 9, no holding is required.

In the above-mentioned embodiment, a hole is formed as a rotary operating tool engaging portion, but the hole is not limited to such a hole. For example, a required portion of the outer peripheral surface of the piston body may have a cross section of a square, hexagon, etc. Alternatively, the diametrically opposing circumferential surface portion of the required portion of the outer circumferential surface may be cut out into a flat surface, and a wrench may be inserted here using such a polygonal portion and flat surface portion as an engaging portion. ,
A rotary operating tool such as a spanner may be engaged.

As explained above, in the fluid pressure cylinder according to the present invention, the fixing ring is fitted into the ring groove provided around the piston rod at a predetermined position while protruding from the circumferential surface of the rod, and the fixing ring is fitted into the ring groove provided around the piston rod at a predetermined position. A piston body having an enlarged hole having a diameter larger than the outer diameter of the ring and having a female thread formed on its inner circumferential surface is coaxially connected, and a rotary operating tool engaging portion is provided at a required part of the outer surface, and a piston rod is fitted. a piston member having a mating hole and a male thread formed on the outer peripheral surface to be screwed into the female thread of the enlarged hole, the piston member being fitted into the piston rod with its tip abutting the fixing ring; At the same time, a detent piece is engaged in a hole continuously drilled from the piston member to the piston rod, and the enlarged hole of the piston body is fitted into the piston rod from the side facing the piston member with the fixing ring in between. is screwed onto the piston member, and there is no need to drill an axial hole in the piston as in the conventional case.
All you need to do is form a thread on the outer circumferential surface of the small diameter piston member and the circumferential surface of the enlarged hole of the large diameter piston body and screw them together, so even small diameter pistons such as 50 mm or less can be processed. It is easy to carry out without causing any difficulty, and the piston body,
When tightening the piston member and the piston rod together, as long as the piston rod is properly fixed, there is no need to hold the piston member from the outside, and the operation can be easily performed because only the piston body needs to be rotated. Furthermore, since the rotary operating tool can be engaged with the rotating operating tool engaging portion when rotating the piston main body, the outer circumferential surface of the piston main body is not damaged.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a vertical sectional view showing a conventional example. 1...Piston rod, 2...Ring groove, 3...Fixing ring, 4...Piston, 5...Piston body, 6...
Piston member, 7...Piston rod fitting hole portion, 8
… Enlarged hole portion, 13… Hole portion (rotary operating tool engaging portion),
15... Piston rod fitting hole, 18... Hole, 19
...An anti-rotation piece.

Claims (1)

[Scope of utility model registration request] A fixing ring is fitted into a ring groove provided around the piston rod at a predetermined position, protruding from the circumferential surface of the rod, and a female thread is formed on the inner circumferential surface of the piston rod fitting hole with a diameter larger than the outer diameter of the fixing ring. a piston body having a piston rod fitting hole and a female thread of the enlarged hole on the outer circumferential surface; and a piston member formed with a male thread that is screwed into the piston rod, and the piston member is fitted into the piston rod with its tip abutting the fixing ring, and the piston member is continuously drilled from the piston member to the piston rod. A detent piece is inserted into the hole, and the enlarged hole of the piston body, which is fitted into the piston rod from the side facing the piston member with the fixing ring in between, is screwed and fastened to the piston member. Fluid pressure cylinder.