JP2588137Y2 - Fuel injection pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for lubricating between an inner peripheral portion of a housing and an outer peripheral portion of a plunger guide.

[0002]

2. Description of the Related Art In general, there is known a fuel injection pump in which a plunger guide for guiding a pump element up and down is fitted into an inner peripheral portion of a housing. In this type, a cam of the engine is brought into contact with the lower end of the plunger guide, and the plunger guide is moved up and down according to the profile of the cam, whereby the pump element is moved up and down to pump the fuel. .

According to this fuel injection pump,
As the plunger guide moves up and down, the side pressure of the plunger guide is applied to the inner peripheral portion of the housing, which causes a problem that the inner peripheral portion is worn.

[0004]

To solve this problem, lubricating oil flows between the inner peripheral portion of the housing and the outer peripheral portion of the plunger guide, and the lubricating oil lubricates the inner peripheral portion of the housing. It is possible to do. However,
Normal lubricating oil has a low viscosity, so lubricating oil must be constantly pumped in order to always lubricate it. The problem is that the consumption of oil increases and the leaked lubricating oil collects in the plunger and blows out from the control rack hole.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a structure capable of easily lubricating between an inner peripheral portion of a housing and an outer peripheral portion of a plunger guide. It is in.

[0006]

To achieve the above object of the Invention The present invention includes a write-free fit the plunger guide for guiding the pump element vertically on the inner peripheral portion of the housing
Check the plunger's vertical operating range at the bottom of both housings.
In a fuel injection pump with a viewing window to recognize
A grease injector for injecting grease from a grease filling device is provided between the inner peripheral portion of the housing and the outer peripheral portion of the plunger guide in the viewing window .

[0007]

The plunger guide is usually made of a material harder than the housing, so if the lubrication between the two is insufficient, the inner peripheral portion of the housing will be worn. If grease is injected between the inner peripheral portion of the housing and the outer peripheral portion of the plunger guide through the grease injector, lubrication between the two becomes smooth during operation, so that the inner peripheral portion of the housing is worn during operation. I will not do it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fuel injection pump according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a camshaftless type fuel injection pump which is directly mounted on an engine (not shown) and has a lower end provided with a camshaft and a camshaft built in the engine. It is in contact with a cam (not shown).

The fuel injection pump has a housing 1 in which a plunger barrel 3 is housed. In this plunger barrel 3, there is a plunger 5
The plunger 5 is provided with a delivery valve 7 for feeding the fuel under pressure. The delivery valve 7 is housed in a delivery valve holder 9, and the delivery valve holder 9 is screwed to an upper end of the housing 1. On the other hand, a spring receiver 11 is fixed to the lower end of the plunger 5, and a spring 15 is provided between the spring receiver 11 and the spring receiver 13 of the housing 1. The spring 15 urges the plunger 5 downward. ing.

The plunger 5 and the spring 15 constitute a pump element, which is eventually supported by a lower spring receiver 11, which is housed in a plunger guide 21. The plunger guide 21 is housed inside the housing 1 so as to be movable up and down. Since the plunger guide 21 is urged downward by the spring 15, the plunger guide 21 is fixed to the inner periphery of the housing 1 so as not to fall out of the housing 1. It is stopped by a stop ring 23 fitted in the part.

The above is a brief description of the fuel injection pump. According to this, fuel flows in from the inlet port 25 and is temporarily stored in the fuel pool 27.

The fuel stored here passes through a hole 29, a slit 31 on the outer periphery of the plunger, a vertical hole (not shown) at the center of the plunger, and the like as the plunger 5 moves up and down in conjunction with the camshaft of the engine. Is delivered to the high pressure chamber at the upper end of the plunger 5, from which it is delivered to the injection nozzle (not shown) of the engine through the above-described delivery valve 7. 33 is an air breather.

Thus, according to this embodiment, a grease cup (grease injector) for injecting grease for lubricating between the inner peripheral portion of the housing 1 and the outer peripheral portion of the plunger guide 21 is provided. ) 35 are provided.

Particularly, in this embodiment, the grease cup 3
5 has a feature that it can be attached to the housing 1 without making a special hole.

That is, in this type of fuel injection pump, a viewing window 37 is opened at a lower portion of the housing 1, and a plug 39 is usually fitted in the viewing window 37.
The viewing window 37 is provided for confirming the vertical operation range of the plunger 5. When assembling, the viewing window 37 looks through the viewing window 37 to start the static injection and the plunger 5.
Check with the upper limit.

According to this, a plug 39 (FIG. 2) having an internal thread portion 39a is fitted into the viewing window 37, and a commercially available grease cup 35 (see FIG. 2) is inserted into the internal thread portion 39a of the plug 39. 3) The external thread portion 35a is fitted.

At the time of injecting grease, a tip 35b of the grease cup 35 is attached to a grease filling device (not shown).
When this is operated, grease in the grease filling device is injected between the inner peripheral portion of the housing 1 and the outer peripheral portion of the plunger guide 21 through the grease cup 35. It is obvious that the grease injection work only needs to be performed periodically and need not be performed constantly.

In short, according to this embodiment, grease is injected between the inner peripheral portion of the housing 1 and the outer peripheral portion of the plunger guide 21 through the grease cup 35.
The lubrication of both is smooth, and during operation, the housing 1
The problem that the inner peripheral portion of the member is worn is solved. Also,
This grease cup 35 is used for the viewing window 3 which is already open.
Since it is attached to 7, extra hole processing is unnecessary,
The grease cup 35 can be attached very easily.

It is preferable that this type of grease has a certain degree of viscosity. It is also desirable to use high temperature grease.

[0021]

As is clear from the above description, according to the present invention, grease is injected between the inner peripheral portion of the housing and the outer peripheral portion of the plunger guide through the grease injector. Lubrication becomes extremely smooth.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fuel injection pump according to the present invention.

FIG. 2 is a sectional view showing a plug applied to the fuel injection pump of FIG. 1;

FIG. 3 is a sectional view showing a grease cup applied to the fuel injection pump of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 housing 3 plunger barrel 5 plunger 7 delivery valve 15 spring 21 plunger guide 35 grease cup 37 viewing window 39 plug

Claims (1)

(57) [Scope of request for utility model registration] 1. A write fitted a plunger guide for guiding the pump element vertically on the inner peripheral portion of the housing-free and
Check the plunger's vertical operating range at the bottom of both housings.
In a fuel injection pump with a viewing window to recognize
A fuel injection pump, wherein a grease injector for injecting grease from a grease filling device is provided between the inner peripheral portion of the housing and the outer peripheral portion of the plunger guide in the viewing window .