JPH0429162Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an internal pressure relief plug tool for a hydraulic pipe joint of a hydraulic work vehicle.

BACKGROUND ART FIG. 2 is a sectional view in the longitudinal direction of a pipe showing a connected state of a bite-in type pipe joint. In the figure, 1 is a male thread side oil pipe, 2 is a sleeve side oil pipe, 3 is a sleeve, and 4 is a double nut. In this type of push-in type pipe joint, the outer periphery B of the sleeve 3 is in oil-tight contact with the tapered inner diameter inlet part A of the end of the oil pipe 1 on the male thread side, and the cut-in part C at the tip of the sleeve 3 is 4, the structure is such that the outer circumference of the sleeve-side oil pipe 2 is dug into the outer periphery. However, workers equipped with this bite-in type pipe joint may disconnect the bite-in type pipe joint in order to reconnect the hydraulic circuit. Then, a blind plug for preventing hydraulic oil leakage is attached to the oil pipe end on the side of the work vehicle main body among the oil pipe ends in the detached state.

FIG. 3 is a cross-sectional view of a main part showing a blind plug attached to a male-threaded oil pipe 1 disposed in the main body of a working vehicle. In the figure, 5 is a blind plug and 6 is a fukuro nut. Therefore, the outer peripheral part D of the blind plug 5 is in oil-tight contact with the inner diameter inlet taper part A at the end of the male thread side oil pipe 1, and the blind plug 5 is tightened and fixed by the double nut 6.

Problems that the invention aims to solve When a work vehicle with a blind plug attached to the male-thread side oil pipe of a bite-in type pipe joint starts and stops the engine, a considerable amount of internal pressure (internal oil pressure) remains in the male-thread side oil pipe. There are some things that have been done. In this state, loosen the hook nut in order to remove the blind plug for reasons such as changing the hydraulic circuit connection. Then, due to the internal pressure inside the oil pipe, the blind plug would pop out, hydraulic oil would spray out, and the worker would be covered in oil. There was also a risk of injury to workers when the blind plug protruded. Furthermore, in some cases, the outer circumferential portion of the blind plug tightened by the double nut was stuck to the inner diameter inlet taper portion of the end of the oil pipe on the male thread side, making it difficult to remove.

This invention solves the above problems and eliminates the problem of hydraulic oil spraying and scattering due to internal pressure and blind plug protruding.
Another object of the present invention is to provide an internal pressure relief tool for a hydraulic pipe joint that does not cause difficulty in removing a blind plug.

Means for Solving the Problems The means of the present invention taken to solve the above problems are as follows: (a) The outer periphery is oil-tightly applied to the inner diameter inlet taper part of the male thread side oil pipe end of the bite-in type pipe joint for hydraulic piping. A plug member is provided in contact with the plug member, a stepped through hole having an internal oil chamber is provided in the plug member, and a threaded hole portion is provided on the outside inner diameter of the through hole, and
A valve seat is provided in the stepped portion between the internal oil chamber and the inner through hole, and (b) a threaded shaft having a tip poppet and a shaft center passage hole is screwed into the threaded hole, and the threaded shaft is screwed into the threaded hole. The tip poppet of the shaft can be brought into oil-tight contact with the valve seat of the plug member, and the plug member can be fixed to the end of the oil pipe on the male thread side using a half black nut.

Operation A: Attach the internal pressure relief plug tool to the end of the male-threaded oil pipe and tighten the double nut and threaded shaft to prevent the hydraulic oil in the male-threaded oil pipe from leaking to the outside.

(b) When removing the internal pressure relief plug tool attached to the end of the male-thread side oil pipe, loosen the threaded shaft in advance. The gap between the valve seat and the tip poppet of the threaded shaft,
The oil is led out through the internal oil chamber of the plug member and the passage hole of the threaded shaft.

Embodiments Hereinafter, embodiments of this invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of the internal pressure relief plug tool according to this invention, which is attached to a male-thread side oil pipe 1 disposed in the main body of a working vehicle. In the figure, 7
8 is the internal oil chamber of the plug member 7; 9 is the plug member; 8 is the internal oil chamber of the plug member 7;
10 is a threaded hole portion, 10 is an inner through hole, 11 is a valve seat of the plug member 7, 12 is a threaded shaft, 13 is a threaded portion of the threaded shaft 12, 14 is a tip poppet portion, 15 is a passage hole, 16 17 is a locking nut, 17 is a retaining ring, E is an outer circumferential contact part of the plug member 7, and F is a shaft 1 with a threaded part.
This is the second grip knob.

Next, the structure of the internal pressure relief plug tool according to this invention will be described with reference to FIG. Plug the plug member 7 so that the outer periphery contact portion E of the plug member 7 is in oil-tight contact with the inner diameter inlet taper portion A of the end of the male thread side oil pipe 1.
has been established. A stepped through hole having an internal oil chamber 8 is formed in the plug member 7, a screw hole portion 9 is provided on the outside inner diameter of the through hole, and a stepped through hole is formed between the internal oil chamber 8 and the inner through hole 10. A valve seat 11 is provided in the section. on the other hand,
The tip poppet portion 14 is attached to the screw hole portion 9 of the plug member 7.
A threaded shaft 12 having a threaded portion was screwed. The tip poppet portion 14 of the threaded shaft 12 can be brought into oil-tight contact with the valve seat 11 of the plug member 7, and
A passage hole 15 is bored inside the threaded shaft 12 to communicate the internal oil chamber 8 of the plug member 7 with the outside. At the same time, the plug member 7 is configured to be able to be fixed to the end portion of the male thread side oil pipe 1 by means of a fukuro nut 16. The retaining ring 17 is provided to prevent the fukuro nut 16 and the plug member 7 from being separated.

Next, the functions of the internal pressure relief plug tool according to this invention will be described. When the bite-type pipe joint is in a disconnected state, the internal pressure release plug tool of this invention is attached to the end of the male thread side oil pipe 1, and the double nut 16 is tightened. And the threaded shaft 1
When the threaded part is tightened by holding the knob part 2, the valve seat 11 of the plug member 7 and the tip poppet part 14 of the threaded shaft 12 come into close contact, so the hydraulic oil in the male thread side oil pipe 1 flows out to the outside. do not. Also, when removing the internal pressure relief plug tool attached to the end of the male thread side oil pipe 1, loosen the threaded shaft 12 in advance.
The pressure oil reserved inside the male thread side oil pipe 1 is transferred to the inner through hole 10 of the plug member 7, the gap between the valve seat 11 of the plug member 7 and the tip poppet portion 14 of the threaded shaft 12, and the inside of the plug member 7. The oil is led out through the oil chamber 8 and the passage hole 15 of the threaded shaft 12. Thereby, the pressure oil reserved inside the male thread side oil pipe 1 is prevented from spouting and scattering to the outside.

Effects of the invention In the conventional technology, when the hydraulic nut is loosened to remove the blind plug at the end of the oil pipe on the male thread side, the internal pressure retained in the oil pipe causes the blind plug to pop out and the hydraulic oil to spout and scatter, making it difficult to carry out work. Some people were covered in oil.

However, if the internal pressure relief plug tool according to this invention is attached to the end of the male-threaded oil pipe instead of the blind plug, the hydraulic oil in the male-threaded oil pipe will not flow out to the outside by tightening the double nut and the threaded shaft. Further, when removing the internal pressure release plug tool, the threaded shaft is loosened in advance, and the pressure oil retained in the male thread side oil pipe is led out to the outside through the passage hole of the threaded shaft. Therefore, the internal pressure release plug tool according to this invention prevents the hydraulic oil and the blind plug from coming out from the male thread side oil pipe end of the hydraulic piping for a working vehicle, and improves the workability and safety of hydraulic circuit connection replacement work. improve.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the internal pressure relief plug tool according to this invention, Fig. 2 is a cross-sectional view showing the connection state of the bite type pipe joint, and Fig. 3 is a cross-sectional view of the main part showing the blind plug attached to the male thread side oil pipe. It is. 1...Male thread side oil pipe, 4, 6, 16...Fukuro nut, 5...Blind plug, 7...Plug member, 8
... Internal oil chamber, 11 ... Valve seat, 12 ... Threaded shaft, 14 ... Tip poppet, 15 ... Passage hole.

Claims (1)

[Scope of utility model registration request] A threaded shaft with a poppet is screwed onto the pressure outlet of the hydraulic pipe body, and a threaded shaft is attached to the axial center of the threaded shaft at a position outward from the valve seat abutting part of the poppet. A valve tool that extracts the pressure inside the hydraulic pipe by drilling a passage hole penetrating outward and opening the valve seat abutting part of the poppet, and the valve tool is a push-in type of hydraulic pipe. A plug member whose outer periphery abuts in an oil-tight manner is provided at the inner diameter inlet taper portion of the male thread side oil pipe end of the pipe joint,
A stepped through hole with an internal oil chamber is bored in the plug member, a screw hole is provided on the outside inner diameter of the through hole, and a valve seat is provided in the stepped portion between the internal oil chamber and the inner through hole. On the other hand, a threaded shaft having a tip poppet portion and a shaft center passage hole is screwed into the threaded hole portion, and the tip poppet portion of the threaded shaft is brought into oil-tight contact with the valve seat of the plug member. An internal pressure relief plug tool for a hydraulic pipe joint, characterized in that the plug member can be fixed to the end of the oil pipe on the male thread side using a double nut.