JPH0545916Y2 - - 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.

Prior Art FIG. 3 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 fukuronut, 2 is an oil pipe on the side provided with the fukuronut 1, 3 is a sleeve, and 4 is an oil pipe on the male thread side.
A push-in type pipe joint like this type has a sleeve 3 attached to the inner diameter inlet taper part of the 4 end of the oil pipe on the male thread side.
The outer periphery (b) of the sleeve 3 is in oil-tight abutment, and the recessed portion (c) at the tip of the sleeve 3 is configured to be recessed into the outer periphery of the oil pipe 2 by tightening the fukuro nut 1. However, a work vehicle equipped with this bite-type pipe joint may disconnect the bite-type pipe joint in order to change the connection of 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. 4 is a sectional view of a main part showing a blind plug 5 with a male thread attached to an oil pipe 2 disposed in a work vehicle main body (not shown). The blind plug 5 has a male screw portion D on its outer periphery and a tapered hole portion E on its inner diameter entrance. Then, the blind plug 5 is tightened and fixed by the fukuro nut 1.

Problems that the invention aims to solve When a work vehicle with a blind plug attached to the oil pipe on the side of the oil pipe equipped with the double nut of a bite-in type pipe joint starts and stops the engine, considerable internal pressure (internal hydraulic pressure) builds up inside the oil pipe. ) may be on hold. In this state, loosen the hook nut in order to remove the blind plug for reasons such as changing the hydraulic circuit connection. As a result, the internal pressure inside the oil pipe caused the blind plug to pop out and the hydraulic oil to spray and scatter, leaving the operator covered in oil.

This invention solves the above-mentioned problems and provides an internal pressure relief tool for hydraulic pipe joints that prevents working oil from spewing out and scattering and blind plugs from popping out due to internal pressure.

Means for Solving the Problems The means of this invention taken to solve the above problems are as follows: (a) The internal pressure relief tool for hydraulic pipe joints of the present invention has a female thread side attached to the outer periphery of the end of the oil pipe. Hydraulic piping in which a hook nut for a bite-in type pipe joint is inserted so as to face the terminal side, and a sleeve for a bite-in type pipe joint is inserted on the outer periphery of the end of the oil pipe at a position inside the female thread of the hook nut. A valve tool is provided with a pipe end stopper attached to the connection end of the pipe, and the pressure inside the oil pipe is released to the outside by loosening the pipe end stopper, and (b) prevents the hydraulic pipe from becoming wedged. A plug member with a male thread that can be screwed into the screw hole of the double nut provided at the end of the type pipe joint is screwed into the screw hole of the double nut, and the end of the oil pipe is inserted inside the male thread of the plug member. an inner diameter inlet tapered part that can come into contact with the inner sleeve of the double nut, and a through hole passing through the axis of the plug member; The stepped through hole is formed by setting the hole diameter of the through hole portion to be smaller than the inner diameter of the oil pipe, and setting the hole diameter of the outer through hole portion that opens to the outside to be larger than the hole diameter of the inner through hole portion. , C. Also, the inner side of the outer through-hole is formed into an internal oil chamber, and the side that opens to the outside is formed into a screw hole,
A valve seat is provided in the stepped portion between the internal oil chamber and the inner through hole, and (2) a threaded shaft having a tip poppet is screwed into the screw hole of the outer through hole of the plug member. The tip poppet of the threaded shaft is brought into oil-tight contact with the valve seat of the plug member, and a passage hole is bored inside the threaded shaft to communicate the internal oil chamber of the plug member with the outside. It was configured as follows.

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

When removing the internal pressure relief plug tool attached to the end of the oil pipe on the side with the double nut, loosen the threaded shaft in advance.
It is led out through the gap between the valve seat of the plug member and the tip poppet of the threaded shaft, 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 a first embodiment of the internal pressure relief plug tool according to this invention, which is attached to an oil pipe 2 disposed in the main body of a working vehicle. In the figure,
6 is a plug member, 7 is an internal oil chamber of the plug member 6,
8 is a male threaded portion, 9 is an inner through hole, 10 is a valve seat of the plug member 6, 11 is a screw hole portion, 12 is a shaft with a threaded portion, 13 is a threaded portion of the shaft with a threaded portion 12, 14 is a tip poppet portion, 15 is a through hole, F is an inner diameter inlet taper portion of the plug member 6, and G is a gripping knob portion of the threaded shaft 12.

Next, the structure of the first embodiment of the internal pressure relief plug tool according to this invention will be described with reference to FIG. Male thread part 8 that can be screwed into the threaded hole of the double nut 1 provided at the end of the hydraulic piping for a bite-in type pipe joint.
The plug member 6 having the above-mentioned fukuronut 1
The male threaded portion 8 of the plug member 6 has an inner diameter inlet tapered portion that can come into contact with the terminal end face of the oil pipe 2 and the sleeve 3 inside the fukuronut 1. A through hole passing through the axis of the plug member 6 is drilled, and the diameter of the inner through hole portion 9 that opens to the inner diameter inlet taper portion of the through hole is smaller than the inner diameter of the oil pipe 2, and on the outside side. The hole diameter of the outer through hole to be opened is set larger than the hole diameter of the inner through hole 9 to form a stepped through hole, and the deep side of the outer through hole is connected to the internal oil chamber 7. A screw hole 11 is formed on the side that opens to the outside, and a valve seat 10 is formed in the stepped portion between the internal oil chamber 7 and the internal through hole 9.
Further, a threaded shaft 12 having a tip poppet portion 14 is screwed into the threaded hole portion 11 of the outer through-hole portion of the plug member 6, and the threaded shaft 1
2 to the valve seat 1 of the plug member 6.
0 in an oil-tight manner, and a passage hole 15 is bored inside the threaded shaft 12 to communicate the internal oil chamber 7 of the plug member 6 with the outside.

Next, the operation of the first embodiment of the internal pressure relief plug tool according to this invention will be described. When the bite-type pipe joint is disconnected, the internal pressure relief plug tool is attached to the end of the oil pipe 2, and the hook nut 1 is tightened. When the threaded portion is tightened by holding the knob of the threaded shaft 12, the valve seat 10 of the plug member 6 and the tip poppet portion 14 of the threaded shaft 12 are tightened.
are in close contact with each other, so the hydraulic oil in the oil pipe 2 does not leak to the outside. In addition, when removing the internal pressure relief plug tool attached to the end of the oil pipe 2, by loosening the threaded shaft 12 in advance, the pressure oil reserved inside the oil pipe 2 is released through the internal through hole 9 of the plug member 6 and into the plug. It is led out through the gap between the valve seat 10 of the member 6 and the tip poppet portion 14 of the threaded shaft 12, the internal oil chamber 7, and the passage hole 15 of the threaded shaft 12. This prevents the pressure oil reserved inside the oil pipe 2 from spouting and scattering to the outside.

FIG. 2 is a sectional view of a second embodiment of the internal pressure relief plug tool according to this invention. In the figure, 16
1 is an oil pipe having a neck portion at its end; 17 is a fukuro nut; 18 is a plug member with a male thread; and 12 is a shaft with a thread. Therefore, an inner diameter inlet tapered portion is provided at the end of the oil pipe 16. Therefore, the outer circumference of the tip end of the plug member 18 can come into oil-tight contact with the tapered inner diameter inlet portion of the oil pipe 16. The other configurations and functions are the same as those of the internal pressure relief plug tool of the first embodiment.

Effects of the invention In the conventional technology, when removing the blind plug attached to the end of the oil pipe on the side equipped with the oil pipe, if the oil nut is loosened, the blind plug may pop out or operate due to the internal pressure held in the oil pipe. Oil gushed out and scattered, leaving workers covered in oil.

However, if the internal pressure relief plug tool according to this invention is attached to the end of the oil pipe instead of the blind plug,
By tightening the double nut and threaded shaft,
The hydraulic oil inside the oil pipe does not leak to the outside. Also, when removing the internal pressure relief plug tool, if you loosen the screw member shaft in advance, the pressure oil retained in the oil pipe will be released.
It is guided to the outside through the passage hole of the threaded shaft.
Therefore, the hydraulic pressure drain plug tool according to this invention prevents hydraulic oil and blind plugs from protruding from the oil pipe end of hydraulic piping for work vehicles, and improves the workability and stability of hydraulic circuit connection replacement work. let

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a first embodiment of the internal pressure relief plug tool according to this invention, Fig. 2 is a cross-sectional view of the internal pressure relief plug tool of the second embodiment, and Fig. 3 is a cross-sectional view showing the connection state of the bite-type pipe joint. Figures 4 and 4 are sectional views of essential parts showing a blind plug attached to the oil pipe on the side provided with the fukuronut. 1,17...Fukuronutu, 2,4,16...
Oil pipe, 5...Blind plug, 6, 18...Plug member, 7...Internal oil chamber, 10...Valve seat, 12...Shaft with threaded portion, 14...Tip poppet portion, 15...Passage hole.

Claims (1)

[Scope of utility model registration request] Insert a hook nut for a bite-in type pipe joint onto the outer periphery of the end of the oil pipe so that the female thread side faces the end of the oil pipe, and insert it onto the outer periphery of the end of the oil pipe at a position inside the female thread of the hook nut. Attach a pipe end stopper to the connecting end of the hydraulic pipe into which a sleeve for a bite-in type pipe joint is inserted, and release the pressure inside the oil pipe to the outside by loosening the pipe end stopper. In this valve tool, a plug member having a male thread that can be screwed into the screw hole of a double nut provided at the end of the hydraulic piping for a bite-in type pipe joint is screwed into the screw hole of the double nut. forming an inner diameter inlet taper portion on the inside of the male threaded portion of the plug member that can abut the end face of the oil pipe and the sleeve inside the double nut, and drilling a through hole passing through the axis of the plug member; The hole diameter of the inner through hole that opens at the inner diameter inlet taper of the through hole is smaller than the inner diameter of the oil pipe, and the hole diameter of the outer through hole that opens to the outside is smaller than the hole diameter of the inner through hole. A stepped through hole is formed by setting the diameter to a large diameter, and the deep side of the outer through hole is formed as an internal oil chamber, and the side that opens to the outside is formed as a screw hole, and the inner oil chamber and the inner side are formed as a screw hole. A valve seat is provided in the stepped part with the through-hole part, and a threaded shaft having a tip poppet part is screwed into the threaded hole part of the outer through-hole part of the plug member, and the threaded shaft The tip poppet of the plug is brought into oil-tight contact with the valve seat of the plug member, and a passage hole is bored inside the threaded shaft to communicate the internal oil chamber of the plug member with the outside. Internal pressure relief plug tool for hydraulic pipe joints.