JP3383593B2 - Rod connecting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod connecting device and is used, for example, in a double rod cylinder to connect a piston and two left and right rods by a screw connection so as not to loosen.

[0002]

2. Description of the Related Art In a conventional double rod cylinder, in order to connect a piston and two left and right rods, one of the rods has a male thread at its tip and the other rod has a female thread at its tip. They are provided respectively, and the male screw and the female screw are fastened with the piston sandwiched by the two rods.

A set screw is attached to the screw portion in order to prevent the screw from loosening.

[0004]

However, in order to attach the set screw, it is necessary to use a drill to make a hole in the rod and then tap the rod at the assembly site of the piston.

Therefore, the number of man-hours for drilling and tapping causes a cost increase. Further, cutting chips are generated during these processes, but if both rod cylinders are assembled with the generated cutting chips attached, it may cause a failure. Therefore, it is necessary to completely remove the cutting chips. The work for that is difficult and is a factor that further raises the cost.

Although there is a method of fixing the connected screw portions with an adhesive, when the adhesive is used, the product inspection cannot be performed until it is completely hardened, so that the process It causes delay. In addition, since the adhesive must be completely degreased and the curing time must be maintained, an unstable element remains in its effect and working process.

The present invention has been made in view of the above-mentioned problems, and connects two rods without loosening them without drilling or tapping during assembly, without using an adhesive. It is an object of the present invention to provide a rod connecting device for connecting the rod.

[0008]

A device according to a first aspect of the present invention is a device for axially connecting a first rod 13 and a second rod 14 to each other. A male screw 22 is provided at one end portion, a fold portion 23 projecting in the axial direction is provided at the tip end portion of the male screw 22, and a female screwed with the male screw 22 is provided at one end portion of the second rod 14. A screw 32 is provided, and a peripheral groove 33 having a diameter larger than that of the female screw 32 is provided on a peripheral wall of the inner portion of the female screw 32 so that the fold portion 23 can enter when the fold portion 23 is plastically deformed. At the center of the inner part of the female screw 32, the female screw 3
2 when the male screw 22 and the male screw 22 are tightened.
A top portion 40 having a taper surface 41 for abutting against the inner peripheral surface of 3 to plastically deform the pleated portion 23 outward is provided.

In the apparatus according to the second aspect of the present invention, the top portion 40 is fitted in the recess 34 provided in the central portion of the inner portion of the female screw 32 with a clearance and aligned in the radial direction. It is provided as possible.

[0010]

1 is a cross-sectional view showing a main part of a double rod cylinder 1 according to the present invention. In FIG. 1, both rod cylinders 1 include a cylinder tube 11, a piston 12 that slides on the inner peripheral surface of the cylinder tube 11, two piston rods 13 and 14 connected to the piston 12, and both ends of the cylinder tube 11. It is composed of a cover (not shown) that closes.

The two piston rods 13 and 14 are screwed to each other while sandwiching the piston 12. FIG. 2 is a sectional view showing a state where the piston rods 13 and 14 are screwed together, and FIG. 3 is a sectional view showing a state before the piston rods 13 and 14 are screwed together.

2 and 3, the first embodiment according to the present invention
Of the small diameter portion 2 at one end of the piston rod 13
1 is formed, and a male screw 22 is formed on the outer peripheral surface of the small diameter portion 21. Further, a fold portion 23 protruding in the axial direction is provided at the tip of the male screw 22, that is, the tip of the small diameter portion 21.

A concave hole 31 is formed at one end of the piston rod 14 which is the second rod according to the present invention.
A female screw 32 that is screwed into the male screw 22 is provided on the inner peripheral surface of the. A peripheral groove 33 having an inner diameter larger than that of the female screw 32 is provided on the peripheral wall of the recessed hole 31 deeper than the female screw 32 so that the pleated portion 23 can enter when the plastic deformation occurs. Further, the concave hole 31 is provided with a concave portion 34, which is deeper than the circumferential groove 33, into which the top member 40 is fitted.

The top member 40 includes a female screw 32 and a male screw 22.
When and are tightened, they are for abutting against the inner peripheral surface 23a of the fold portion 23 to plastically deform the fold portion 23 outward, and are composed of a tapered surface 41 and a columnar portion 42.

The diameter of the columnar portion 42 is set to be slightly smaller than the inner diameter of the recess 34, so that the columnar portion 42 fits in the recess 34 with a clearance. When the taper surface 41 abuts the inner peripheral surface 23a of the fold portion 23, a force for centering acts between the fold portion 23 and the top member 40, but the clearance is adjusted at that time. It is provided so that the top member 40 can move according to the core action.

A packing for sealing is provided between the piston rod 13 or 14 and the piston 12. Next, the state when the piston rods 13 and 14 are tightened will be described.

As shown in FIG. 3, the pleats 23 do not come into contact with the female screw 32 before tightening. As the tightening progresses, the taper surface 41 of the top member 40 forms the fold 2
The inner peripheral surface 23a of 3 is pushed into the inner peripheral surface 23a, and the folds 23 are pushed outward.

At the time when the tightening of the piston rods 13 and 14 is completed, as shown in FIG. 2, the pleats 23 are plastically deformed and abut against the female threads 32, and between the pleats 23 and the female threads 32. It will be in a state of biting into each other. The pleats 23 enter the circumferential groove 33, but do not contact the circumferential groove 33.

In this state, the fold portion 23 is pressed against the female screw 32 with a strong force, and the fold portion 23 is plastically deformed, so that the piston rod 13,
External force to rotate 14 causes the folds 2
The deformation of 3 does not return and the screw connection does not loosen.

When tightening the piston rods 13 and 14, in order to prevent seizure, the male screw 22 and the female screw 32 are coated with lubricating oil or filled with grease.

According to the above-described embodiment, the folds 23 are plastically deformed and the loosening of the screw connection is prevented by rotating the piston rods 13 and 14 and tightly tightening them. That is, the two piston rods 13 and 14 can be connected by screw connection without loosening.

Therefore, it is not necessary to perform drilling or tapping at the time of assembly as in the conventional case, and it is not necessary to use an adhesive agent, and the piston rods 13 and 1 are not required.
4 can be connected only by tightening the piston rods 13 and 14.

Further, when the folds 23 are plastically deformed, by using the top member 40 having the tapered surface 41, the tightening force is increased, and the inclination of the tapered surface 41 prevents loosening. In addition, the deformation cannot be restored unless it is stronger than the tightened force.

In the above embodiment, carbon steel, stainless steel, aluminum alloy or the like is used as the material of the piston rods 13 and 14 and the top member 40.
A male screw is not formed on the outer peripheral surface of the fold portion 23,
As long as the pleats 23 are thick enough to undergo plastic deformation, the male screws 22 may be provided in all or in part. Although the pleats 23 are formed in a cylindrical shape, it is also possible to make notches in the axial direction at appropriate intervals in the circumferential direction to facilitate plastic deformation.

Although the top member 40 is provided separately from the piston rod 14 in the above embodiment, the top member 40
May be provided integrally with the piston rod 14. Other,
The structure, shape, size, number, material, etc. of the piston rods 13 and 14, the piston 12, or the whole or each part of both rod cylinders 1 can be appropriately changed in accordance with the gist of the present invention.

In the above embodiment, the double rod cylinder 1
Although the example in which the present invention is applied has been described above, the present invention can be applied to connection of various rods other than the cylinder device.

[0027]

According to the present invention, it is possible to connect two rods without loosening without drilling or tapping during assembly, without using an adhesive.

According to the second aspect of the present invention, since the top portion is automatically centered as the rod is tightened, the plastic deformation of the fold portion is smoothly performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a double rod cylinder according to the present invention.

FIG. 2 is a cross-sectional view showing a state where a piston rod is screwed.

FIG. 3 is a cross-sectional view showing a state before the screw connection of the piston rod is performed.

[Explanation of symbols]

1 double rod cylinder 13 Piston rod (first rod) 14 Piston rod (second rod) 22 Male screw 23 Fold 32 female screw 33 circumferential groove 34 recess 40 Top member (top) 41 Tapered surface

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 64-6403 (JP, U) Rikai Sho 63-4406 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F15B 15/14 320 F15B 15/14 375

Claims (2)

(57) [Claims] 1. A device for axially connecting a first rod and a second rod, wherein a male screw is provided at one end of the first rod, and a tip end portion of the male screw is provided. A fold portion projecting in the axial direction is provided, a female screw that is screwed with the male screw is provided at one end of the second rod, and the fold portion is plastically deformed on the inner peripheral wall of the female screw. A peripheral groove having a diameter larger than that of the female screw is provided so that the female screw and the male screw are tightened at the center of the inner part of the female screw. 2. A rod connecting device, comprising: a top portion having a taper surface for abutting an inner peripheral surface of the member and plastically deforming the fold portion outward. 2. The top of the female screw is fitted in a recess provided in a central portion of the inner part of the female screw with a clearance so as to be radially aligned. Rod connecting device.