JPS6026201Y2 - Air control device for fuel injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air control device for a fuel injection device.

In recent automobiles, improvements in drivability and responsiveness, particularly in acceleration and deceleration, are increasingly desired.

This means that even if the driver tries to accelerate by stepping on the accelerator,
If the accelerator is too heavy, it will be difficult to start the car right away, and in the worst case scenario, it may lead to an unexpected accident.

The first step to this is to eliminate causes such as friction between the link system of the air control device, especially between the throttle valve shaft and the bearing.

Generally, a carburetor has a fuel outlet above the throttle valve, so when the engine rotates, the fuel mixed with air always flows through the throttle valve to the throttle valve shaft and bearing, and at this time, between the bearing and the throttle valve shaft. Friction between the throttle valve shaft and bearing is not much of a problem because it has the effect of cleaning impurities and wear particles accumulated in the throttle valve, but in the air control system for fuel injection equipment, the fuel system and air control system are separate bodies. Also, since the fuel system is located downstream of the air control system, it is rarely cleaned with fuel like the carburetor.

For this reason, there has been a phenomenon in which impurities due to engine blowback or the like or abrasion powder and dust entering from the outside accumulate between the bearing and the throttle valve shaft.

A possible solution to this phenomenon is to use a structure similar to that of general butterfly valves, in which the inner ring of a ball bearing having balls between the inner and outer rings is press-fitted onto the throttle valve shaft to bear the throttle valve shaft.

However, such a structure causes problems as described later.

First, an air control device for a fuel injection device will be explained.

Figure 1 shows the structure of the fuel injection system.
An intake pipe 2 and an air control device 3 are connected to the intake pipe 2 and the air control device 3.

A fuel injection valve 4 is provided downstream of the air control device 3, and fuel is supplied from a fuel tank 5, a filter 6, and a fuel pump 7.

Note that a fuel pressure regulator 8 is provided to keep the fuel pressure constant.

A signal is sent to the fuel injection valve 4 from a control unit 10 that determines the opening time of the fuel injection valve 4 based on information sent from various sensors 9.

2 and 3 show the configuration of an air control device using the above-mentioned inner ring press-fit ball bearing, and a throttle valve 12 is connected to the throttle valve shaft in an intake passage 11 formed in the air control device 3. 13
is fixed.

The throttle valve shaft 13 is connected to a wall portion 14 forming the intake passage 11.
It is supported by a bearing consisting of an outer ring 15, a ball 16, and an inner ring 17 that are press-fitted into the bearing.

The inner ring 17 and the throttle valve shaft 13 are press-fitted and fixed.
The throttle shaft 13 is rotated by a ball 16.

Such a bearing method is described, for example, in r Machinery and Equipment Handbook p.248.
, shown in the 1st prize of the 7th edition of July 5, 1939.

However, in this case, the inner ring 17 and the throttle valve shaft 13 are press-fitted and fixed, so when the inner ring 17 is press-fitted into the throttle valve shaft 13, the force at the time of press-fitting acts to bend the throttle valve shaft 13, making it difficult to force it. This results in the assembly of these items.

Therefore, there is a problem in that the movement of the throttle valve shaft 13 becomes unsmooth.

An object of the present invention is to provide an air control device that allows a throttle valve shaft to rotate smoothly.

The feature of the present invention is that the outer ring of the bearing having balls between the inner ring and the outer ring is press-fitted into the wall of the intake passage, and the throttle valve shaft is inserted through the inner ring with a predetermined gap.

Hereinafter, explanation will be made according to FIG. 4 of the drawings.

In FIG. 4, the throttle valve shaft 13 is inserted into the inner ring 17 with a predetermined minute gap 18 interposed therebetween.

When the inner ring 17 is inserted into the throttle valve shaft 13, it can be inserted through the small gap 18 without applying any unreasonable force, so that no bending action occurs on the throttle valve shaft 13.

Therefore, the movement of the throttle valve shaft 13 becomes smooth.

On the other hand, due to this gap, when impurities or the throttle valve shaft swings,
Since it comes into contact with the inner ring of the bearing, abrasion powder from this part will enter the gap, but in this case, the throttle valve shaft 13 and the inner ring 17 are press-fitted, so the inner ring 17 is rotated by the balls 16, causing no inconvenience. It's something that doesn't exist.

It should be noted that if the gap 18 is made too large, the wear of the throttle valve shaft 13 and the inner ring 17 will increase, which is not preferable.

This is because as wear increases, excess air tends to enter.

For this reason, when examining the relationship between the clearance of the inner ring 17 and the amount of wear on the throttle valve shaft 13, a relationship as shown in FIG. 5 is obtained.

As can be seen from this figure, when the gap is increased to 0.2 mm or more, wear increases rapidly.

Therefore, the gap is 0.2rrr! It is preferably n or less.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a fuel injection device, Figure 2 is a cross-sectional view of a conventional air control device, Figure 3 is a cross-sectional view taken along
The figure is a sectional view of a main part of the air control device according to the present invention, and FIG. 5 is a diagram showing the relationship between the gap between the shaft and the inner ring and the amount of wear. 2... Intake pipe, 3... Air control device,
4... Fuel injection valve, 11... Intake passage, 12... Throttle valve shaft, 13... Throttle valve, 1
4...Wall part, 15...Outer ring, 16...
...Ball, 17...Inner ring, 18...
...Small gap.

Claims (1)

[Claims for Utility Model Registration] 1. Used in a fuel injection device that injects fuel at positive pressure into the intake passage via a fuel injection valve in accordance with the amount of intake air flowing through an intake passage connected to an engine, In an air control device for a fuel injection device, the air control device is fixed to a throttle valve shaft extending through the intake passage, which is supported on a wall of the intake passage upstream of a fuel injection valve, and adjusts the amount of air flowing through the intake passage.
The outer ring of a bearing having balls between the outer ring and the inner ring is press-fitted into the wall of the intake passage, and the throttle valve shaft is inserted into the inner ring with a predetermined minute gap between the inner ring and the inner ring. Air control device for equipment. 2. The air control device for a fuel injection device according to claim 1 of the utility model registration claim, wherein the predetermined minute gap is at most 0.2 Wn.