JPH0331465Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a tack device, particularly a hydraulically operated tack device.

Hydraulically actuated rivet devices, which have been widely used in the manufacture of chassis frames for large vehicles, usually have a hydraulic cylinder mounted on one end of a roughly C-shaped frame or yoke, and a hydraulic cylinder mounted inside the cylinder. It has a structure in which a piston that is driven reciprocally by hydraulic pressure is fitted, and a snap for crimping a rivet head is removably attached to the shaft end of the piston. The snap has a head forming a rivet head at one end thereof, and a shaft handle portion detachably fitted into a fitting hole provided at the end of the piston shaft at the other end, Furthermore, a rubber ring (usually an O-ring) is installed in the shaft handle to prevent the snap from falling off, and the snap is frictionally held on the piston shaft by the frictional force generated by compression of the ring. It is configured to In such a rivet device, when the snap is inserted into the fitting hole at the end of the piston shaft,
Because the rubber ring tightly adheres to the wall of the fitting hole and generates a frictional locking force, the air inside the fitting hole does not escape.
There is a risk that the riveting operation may be performed in a state where the stem portion of the snap is not fully inserted into the fitting hole. In this case, there is a risk that an extremely large bending force will be applied to the shaft portion of the snap, resulting in problems such as breakage of the snap shaft portion or deformation of the snap fitting hole at the end of the piston shaft. In particular, if the fitting hole at the end of the piston shaft is deformed, the expensive piston shaft itself must be replaced, resulting in a significant economic loss.

The present invention was devised in view of the above, and includes a frame having a roughly C-shape, a cylinder mounted on one end of the frame, and a cylinder fitted in the cylinder so as to be slidable and driven by fluid pressure. piston,
A snap whose shaft portion is removably fitted into a fitting hole provided at the shaft end of the piston, and a fitting hole between the shaft portion and the piston shaft end to prevent the snap from falling off. The object of the present invention is to provide a rivet device comprising a ring made of an elastic material such as rubber interposed between the fitting hole and the fitting hole, which is characterized by providing a ventilation path that directly communicates the inner part of the fitting hole with the outside air. It is something to do.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the figure, reference numeral 10 denotes a frame or yoke having a C-shape as a whole, and 12 denotes the frame 1.
A hydraulic cylinder is fastened to one end of the piston 12 by a nut 14, a piston 16 is slidably fitted in the hydraulic cylinder 12, and 18 is attached to the end of the shaft 16' of the piston 16. a mating hole formed;
Reference numeral 20 denotes a snap having a handle 20' that is removably fitted into the fitting hole 18, and 22 a rubber O-ring (not shown) fitted onto the handle 20' of the snap. 24 is deformed into an elliptical shape in the fitted state, but has a circular cross-sectional shape in the free state), and one end of 24 is located deep inside the fitting hole 18 (the fitting hole 18 in the figure). O-ring 22 when inserting the above-mentioned snap shaft handle 20' from the top of
The piston shaft 1 is connected so that the other end thereof is connected to a radial groove 26 cut into the end surface of the piston shaft 16'.
a vent passage provided in 6';
30 is an operation button, and 32 is a well-known hydraulic control device that drives the piston 16 up and down in response to the operation of the operation button 30.

In the above device, the shaft handle portion 2 of the snap 20
0', the O-ring 22 fitted on the outside is
By being pressed against the inner circumferential surface of the fitting hole 18 in the piston shaft 16', it is frictionally held on the piston shaft 16', so that it will not fall easily during the riveting operation. Therefore, the collaborative Snap20,2
By positioning the rivet head to be crimped between 8 and operating the operation button 30, the hydraulic control device 3
2, high-pressure hydraulic oil is supplied to the upper chamber of the piston of the hydraulic cylinder 12, and the piston shaft 16'
Then, the snaps 20 are lowered together to perform the riveting work. When the specified rivet work is completed, hydraulic oil is supplied to the lower chamber of the piston 16 by the operation of the hydraulic control device 32, and the piston shaft 16' rises together with the snap 20 to return to the original position shown in FIG. That's what I do. In addition, when replacing the snap 20 due to wear and tear, etc., insert the shaft handle 20' with the O-ring 22 installed in advance into the fitting hole 18 in the piston shaft 16'.
When inserted into the shaft, the air in the fitting hole 18 sealed by the O-ring 22 passes through the ventilation path 24 and is forced out directly to the outside air from the groove 26, so that the shaft shaft portion 20' can be inserted quickly and easily. The snap 20 is properly installed in the correct position shown. Therefore, the stem part 2
Shaft handle part 2 that often occurs when rivet work is performed with 0' inserted to an incomplete halfway position.
This has the advantage of effectively preventing breakage and deformation of the fitting hole 18 due to a large bending force of 0', thereby improving the durability of the piston shaft 16' that is integrated with the snap 20 and the piston 16. In addition, O shown in the above example
Of course, the ring 22 can be replaced by a ring made of an elastic material such as rubber and has a rectangular cross section.
In the illustrated embodiment, the groove 34 is provided on the piston shaft 16';
It is clear that they can be equally replaced by a vent hole 36 formed in the piston shaft 16' and communicating the groove 34 and the fitting hole 18.

As mentioned above, the rivet device according to the present invention includes a frame having a generally C-shape, a cylinder mounted on one end of the frame, and a rivet device slidably fitted into the cylinder and driven by fluid pressure. A piston to be driven, a snap whose shaft portion is removably fitted into a fitting hole provided at the shaft end of the piston, and a shaft portion and the piston shaft to prevent the snap from falling off. A device comprising a ring made of an elastic material such as rubber interposed between a fitting hole at the end, characterized in that a ventilation passage is provided to directly communicate the inner part of the fitting hole with the outside air, The simple structure effectively prevents damage to the snap and the piston shaft on which the snap is mounted, and improves their durability, which is extremely useful in practice.

[Brief explanation of the drawing]

FIG. 1 is an overall side view showing a part of an embodiment of the present invention in cross section, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 10...Frame, 12...Hydraulic cylinder, 1
6... Piston, 16'... Piston shaft, 18...
...fitting hole, 20...snap, 20'...snap shaft handle, 22...O-ring, 24...ventilation path.

Claims (1)

[Scope of utility model registration request] A frame having a generally C-shape, a cylinder mounted on one end of the frame, a piston slidably fitted in the cylinder and driven by fluid pressure, and provided at the axial end of the piston. A snap whose shaft portion is removably fitted into the fitting hole, and rubber interposed between the shaft portion and the fitting hole at the end of the piston shaft to prevent the snap from falling off. What is claimed is: 1. A rivet device comprising a ring made of an elastic material, characterized in that an air passage is provided to directly connect the inner part of the fitting hole to the outside air.