JPH0571442A - Piping connecting portion structure of pump - Google Patents

Abstract

PURPOSE:To keep chip of a screw from entering a pump when piping is put in the screw-connection state. CONSTITUTION:A pole-like hollow screw 1 is erected on a flange 2 fixed to an opening of a passage 61 of a pump housing 6, and a passage 11 bent like L-shape to open to the side intermediate position and the base end surface is formed in the half portion of the hollow screw 1. A leading end swivel nipple 3 of a fluid pipe 7 is fitted to the outer periphery of the hollow screw 1, and gaskets 41, 42 are brought into close contact with both end surfaces to be positioned and fixed by T-bolts 51 engaged with the leading end female screw portion 1a of the hollow screw. Even if chip is produced at the time of screwing the T-bolt into the female screw portion, the chip can be prevented from entering the swivel nipple 3 by the gaskets 41, 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for connecting a pipe of a pump, and more particularly to a structure for preventing chips from a screw portion for connecting and fixing a fluid pipe from entering the pump.

[0002]

2. Description of the Related Art FIG. 5 shows the structure of a fuel supply section of a column fuel injection pump used in a diesel engine or the like. A vertically extending columnar plunger 81 is provided in the center of the pump housing 6, and the lower end of the plunger 81 abuts on a cam interlocking with the engine via a tappet (not shown) and moves vertically in synchronization with the engine rotation. Be punished.

When the plunger 81 moves up and down, the fuel chamber 8a
Of the fuel is discharged and delivered to the injection valve of each engine cylinder through the delivery valve 821 of the fuel discharge port 82 provided at the top of the housing. The fuel discharge amount is determined by a control sleeve 83 fitted around the outer periphery of the plunger 81, and the position of the control sleeve 83 is changed by an eccentric pin 85 tilted by a control rod 84.

Fuel is supplied to the fuel chamber 8a through a fuel flow path 61 opening to the side wall of the pump housing 6, and a nipple 86 having an internal thread is provided in advance in this opening, and a nipple 86 is provided in the fuel supply pipe. A tubular hollow screw 87, which is provided with an external thread at one end and is threaded, is screwed in and connected.

[0005]

By the way, in the above structure, the cutting dust generated when the hollow screw 87 is screwed into the nipple 86 penetrates into the pump, which causes the sliding portion between the plunger 81 and the control sleeve 83, or It may reach the sliding portion between the plunger 81 and the cylinder 88 and hinder smooth operation.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and an object of the present invention is to provide a structure of a pipe connecting portion of a pump in which chips generated when the pipe is fixed with a screw do not enter the housing.

[0007]

The structure of the present invention will be described with reference to FIG. 3. In the pipe connecting portion structure, a curved flow passage 11 is formed inside the side surface and one end surface of the intermediate portion, 11
The column-shaped hollow screw 1 having a threaded portion 1a at the end portion where no groove is formed, and one end of the hollow screw 1 that is liquid-tightly fixed to the outer wall of the pump housing 6 and is fixed to the outer wall of the pump housing 6.
A flange 2 for communicating 1 with a flow passage 61 in a pump housing 6, and a swivel nipple 3 provided at one end of a fluid pipe 7 fitted to the outer circumference of the hollow screw 1 to form an annular space 3a around the outer circumference. And hollow screw 1
Of the swivel nipple 3 fitted to the screw portion 1a of
And a screw member 51 for fixing it to the surface of the flange 2 via seal members 41 and 42 provided in contact with both end faces thereof.

[0008]

In the above structure, when the swivel nipple 3 provided at one end of the fluid pipe 7 is fitted on the outer periphery of the hollow screw 1 and fixed by the screw member 51, the screw portion of the hollow screw 1 into which the screw member 51 is fitted. 1a is provided at the end portion where the flow path 11 is not formed, and the seal members 41 and 42 are in contact with both end surfaces of the swivel nipple 3, so that chips generated when the screw is fixed pass through the flow path 11. It does not enter the pump.

[0009]

[Embodiment 1] FIG. 1 shows an example in which the present invention is applied to a fuel supply portion of a column injection pump. In the figure, the structure of the pump portion is the same as that of the conventional example, the fuel in the fuel chamber 8a is compressed by the vertically moving plunger 81, and the injection of each engine cylinder is performed via the delivery valve 821 of the fuel discharge port 82 provided at the top of the housing. Discharge pressure is delivered to the valve. The fuel chamber 8a
Is supplied with fuel through a flow path 61, and the fuel flows into the flow path 61 through a swivel nipple 3 (FIG. 2), which will be described later in detail, provided at one end of the fuel supply pipe 7.

The details of the fuel supply section are shown in FIG. 3, and a square flange 2 (FIG. 2) is fixed to the outer wall of the pump housing 6 where the flow passage 61 is opened by bolts 22 provided at diagonal positions to open it. The liquid-tightness of this portion is maintained by an O-ring 21 arranged in a stepped recess on the periphery of the opening.

A base end of a hollow hollow screw 1 is fixed to the center of the flange 2 by welding. Inside the hollow screw 1, the hollow screw 1 extends along the axis from the base end face and bends downward at an intermediate position. A flow channel 11 having an opening on the side surface is formed.
Then, the hollow screw 1 in which the flow path 11 is not formed
A female threaded portion 1a is formed at the tip of the above along the axis from the end face.

The swivel nipple 3 provided at one end of the fuel supply pipe 7 is in the form of a closed cylindrical box having a through hole in the center, and is fitted around the outer periphery of the hollow screw 1 to form an annular space 3a around the outer periphery thereof. The space 3a is formed and the flow path 11 is formed.
Communicate with.

In the swivel nipple 3, a gasket 41 is arranged in contact with one end face of the swivel nipple 3 and the surface of the flange 2 and a gasket 42 is arranged in contact with the other end face of the swivel nipple 3 and fitted into the screw portion 1a. It is positioned and fixed by a T-shaped bolt 51.

The fuel that has passed through the fuel supply pipe 7 is supplied from the inside of the swivel nipple 3 through the flow passage 11 to the flow passage 61 inside the housing 6 as shown by the arrow in FIG.

In such a structure, even if chips are generated when the bolts 51 are fitted to the threaded portion 1a for connecting and fixing the swivel nipple 3, the chips are not removed by the gasket 4
The swivel nipple 3 is prevented from entering the swivel nipples 1 and 42 and does not reach the inside of the housing 6.

[0016]

[Embodiment 2] The screw portion formed at the tip of the hollow screw 1 is not limited to the female screw 1a as in the above embodiment, but is a male screw 1b as shown in FIG. Even if they are fixedly connected, the same effect can be obtained.

Although each of the above embodiments has been described as an example in which the present invention is applied to the fluid (fuel) supply portion of the pump, it can be applied to the fluid discharge portion. Also, instead of the gasket, O
Rings can be used.

[0018]

As described above, according to the pipe connecting portion structure of the present invention, it is possible to effectively prevent the cutting chips generated when the pipes are connected and fixed with screws from entering the pump housing. The smooth operation of the pump can be guaranteed.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a pump showing an embodiment of the present invention.

FIG. 2 is a perspective view of a fuel supply unit of a pump.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view of a pipe connecting portion showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part of a conventional pump.

[Explanation of symbols]

 1 Hollow Screw 1a Female Screw (Screw Part) 1b Male Screw (Screw Part) 2 Flange 3 Swivel Nipple 41, 42 Gasket (Seal Member) 51 T-Shaped Bolt (Screw Member) 52 Nut (Screw Member) 6 Pump Housing 7 Fuel Supply Pipe (fluid piping)

Claims (1)

[Claims] 1. A column-shaped hollow screw having a curved flow passage opening inside the side face and one end face of an intermediate portion, and a threaded portion provided at an end not forming the flow passage, and an outer periphery of one end of the hollow screw. A flange that is formed and is liquid-tightly fixed to the outer wall of the pump housing and that connects the flow path to the flow path inside the pump housing, and a fluid that is fitted to the outer circumference of the hollow screw to form an annular space around the outer circumference. A swivel nipple provided at one end of the pipe, and a screw member that is fitted to the threaded portion of the hollow screw and that fixes the swivel nipple to the flange surface via seal members provided in contact with both end surfaces of the swivel nipple. Pump connection structure for pump.