JPH0219618A - Mounting construction for rotary lever - Google Patents

Abstract

PURPOSE:To reduce contact wear by forming a wide enlarged clearance between the end part of the outer peripheral surface of a lever shaft of an adjusting lever and a sliding contact surface opposed to it in a fuel injection pump. CONSTITUTION:Between a lever shaft 4 supported in a boss part 6a of a housing 6 and a sliding contact surface 7a opposed to it, a fine clearance alpha is provided. Between the end part of the outer peripheral surface of the lever shaft 4 and the sliding contact surface 7a, an enlarged clearance beta wider than the fine clearance alpha is provided. Contact wear between the end part of the outer peripheral surface of the lever shaft 4 and the sliding contact surface can thus be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the installation of a rotary lever such as an adjusting lever that is rotatably operated to control the fuel injection amount in a fuel injection pump for a diesel engine, for example. It's about structure.

[Prior Art] Conventionally, a rotating lever, for example, an adjusting lever for a fuel injection pump, is attached to a housing of the fuel injection pump and is operated to rotate. That is, as shown in FIG. 4, an adjusting lever (hereinafter referred to as rAJ lever) 1 is connected to an accelerator pedal 3 via a wire 2 or the like, and is rotated in conjunction with depression of the accelerator pedal 3.

Here, to explain the general mounting structure of the AJ lever 1, as shown in FIGS. Fixed via 5.

AJ lever shaft 4 is the fuel injection pump housing 6
It is rotatably supported via a bush 7 at a boss portion 6a formed in the. The lower end of the AJ lever shaft 4 projects inside the housing 6 and is connected to one end of a governor spring (not shown) via a joint member 8.

Then, by rotating the AJ lever 1, the AJ
The lever shaft 4 is rotated to change the tension of the governor spring, and the fuel injection amount is controlled via a well-known governor mechanism.

Further, a return spring 9 is wound around the outer periphery of the boss portion 6a for returning the rotation of the AJ lever 1 to its original position, and the biasing force of the return spring 9 acts on the AJ lever 1 at all times.

On the other hand, as shown in FIG. 5, there is a gap between the AJ lever shaft 4 and the bushing 7 inside the boss portion 6a that allows rotation of the AJ lever shaft 4 and allows machining errors of the AJ lever shaft 4. The fine gap α(if
fi (usually about 30 μm) is provided. Further, a recess a4a is formed on the outer peripheral surface of the AJ lever shaft 4, and an 017 ring 10 is fitted into the recess groove 4a. and,
With this O-ring 10 as a boundary, the upper fine gap α is a non-lubricated portion A, and the lower fine gap α is a lubricated portion B. That is, the fuel in the housing 6 is supplied to the lubricating portion B for lubrication. Therefore, 0
The ring 10 functions to prevent the lubricating fuel from leaking, and the lubricating portion B is filled with the lubricating fuel.

[Problems to be Solved by the Invention] However, in the conventional AJ lever shaft 4, when the AJ lever 1 is rotated, the boss portion 6a rotates around the O-ring 10 as shown in FIG. causes a tilt with respect to the central axis of the For this reason, AJ lever shaft 4
The outer circumferential surface end of the AJ lever shaft 4 contacts the inner surface end of the bushing 7, and wear is caused by the contact between the outer circumferential surface upper end 4b of the AJ lever shaft 4, which is the non-lubricated part A, and the inner surface upper end 7a of the bushing 7. There was a fear that this would occur.

When the upper end 4b of the outer circumferential surface of the AJ lever shaft 4 and the upper end 7a of the inner surface of the bushing 7 contact and wear in this way, the inclination of the AJ lever shaft 4 becomes even larger.
There was a risk that the tightness of the ring IO would become smaller and fuel would leak from the lubricating part B.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide rotation that can prevent contact wear between the outer circumferential surface end of a lever shaft and the sliding surface facing the same outer circumferential surface end. The purpose is to provide a lever mounting structure.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a lever shaft is rotatably supported by a boss formed in a housing, and a boss part formed in a housing is rotatably supported. In a rotating lever mounting structure in which a minute gap is provided between the sliding surface facing the outer circumferential surface to allow rotation of the lever shaft, and the rotating lever is fixed at the end of the lever shaft, An enlarged gap wider than the minute gap is provided between the edge of the outer circumferential surface and the sliding surface facing the edge of the outer circumferential surface.

[Function] Therefore, even if the lever shaft is tilted with respect to the center axis of the boss when the rotary lever is rotated, the outer peripheral surface end of the lever shaft and the sliding surface opposite to the outer peripheral surface end are separated from each other by an enlarged gap, and contact between the edge of the outer peripheral surface and the sliding surface is avoided.

[Example] Hereinafter, an example in which the present invention is embodied in a fuel injection pump for a diesel engine will be described in detail with reference to the drawings.

The basic configuration of this embodiment is the same as that of the conventional example. Therefore, the same reference numerals will be given to the same members as in the conventional example, and the explanation will be omitted, and only the different points will be explained.

As shown in FIG. 1, this embodiment differs from the conventional structure in the shape of the AJ lever shaft 4. That is, in the AJ lever shaft 4, the outer diameter of the upper end portion 4b of the outer circumferential surface on the upper side of the concave groove 4a is smaller than the outer diameter of the lower outer circumferential surface. As a result, an enlarged gap β wider than the fine gap α is provided between the upper end 4b of the outer circumferential surface and the upper end 7a of the inner surface of the bushing 7, which serves as a sliding surface facing the upper end 4b of the outer circumferential surface. ing. In this example, the enlarged gap β is about 0.15 mm,
This is about 5 times larger than the fine gap α of about 30 μm.

Note that the size of the enlarged gap β is not limited to the above-mentioned 0.15 mm.

Therefore, even if the AJ lever shaft 4 is tilted with respect to the central axis of the boss portion 6a by rotating the AJ lever 1, the enlarged gap β in the non-lubricated portion A causes the AJ lever shaft 4 to tilt.
The upper end 4b of the outer peripheral surface of the bushing 7 and the upper end 7a of the inner surface of the bushing 7 are separated from each other, and contact between the two 4b and 7a is avoided.

Therefore, occurrence of wear of both 4b and 7a due to contact between the upper end 4b of the outer circumferential surface and the upper end 7a of the inner surface in the non-lubricated portion A is prevented.

As a result, both of the above 4b, ? AJ due to contact wear of a
The inclination of the lever shaft 4 is not increased, the function of the O-ring 10 is ensured, and fuel leakage from the lubricating part B can be prevented.

By the way, when the AJ lever shaft 4 is tilted, the AJ lever shaft 4 comes into contact with the bushing 7 in the lubricating part B, but this is not a problem because the lubricating fuel prevents wear.

Note that this invention is not limited to the above embodiments,
The present invention can be implemented as follows by changing a part of the structure as appropriate without departing from the spirit of the invention.

(1) In the above embodiment, as shown in FIG.
Although the upper end is open, as shown in FIG.
An annular sealing member 12 may be fitted into the stepped portion 11 to seal off the upper end of the non-lubricated portion A. In this case, the seal member 12 can prevent water, dust, etc. from entering from the outside into the non-lubricated portion.

(2) In the above embodiment, as shown in FIG. 1, the outer diameter of the upper end 4b of the outer peripheral surface of the AJ lever shaft 4 is formed small, and the outer diameter is expanded between the upper end 4b of the outer peripheral surface and the upper end 7a of the inner surface. Although a gap β is provided, as shown in FIG. 3, the upper end 7a of the inner surface of the bushing 7 is made to have a larger inner diameter than the other inner diameters, and the upper end 4b of the outer circumferential surface and the upper end 7a of the inner surface are An enlarged gap β may also be provided.

(3) In the above embodiment, as shown in FIG. 1, the outer diameter of the upper end 4b of the outer peripheral surface of the AJ lever shaft 4 is formed small, and the outer diameter is expanded between the upper end 4b of the outer peripheral surface and the upper end 7a of the inner surface. Although the gap β is provided, the outer diameter of the upper end 4b of the outer peripheral surface of the AJ lever shaft 4 is made smaller, and the upper end 7a of the inner surface of the bushing 7 is made larger in diameter than the other inner diameters. An enlarged gap β may be provided between the upper end portion 7a of the inner surface and the upper end portion 7a of the inner surface.

(4) In the above embodiment, as shown in FIG. 1, the AJ lever shaft 4 is supported through the bushing 7, and a fine gap α and an enlarged gap β are provided between the AJ lever shaft 4 and the bushing 7. However, the bushing 7 may be omitted and a fine gap α and an enlarged gap β may be provided between the AJ lever shaft 4 and the boss portion 6a.

(5) In the above embodiment, the fuel injection pump for a diesel engine is used, but the outer circumferential surface of the lever shaft that supports the rotary lever is divided into a lubricated part and a non-lubricated part. It can also be embodied in a similar manner in a partitioned form.

For example, CS D (Cold 5tart Devi
It can also be similarly embodied in the pivot lever of ce).

[Effects of the Invention] As detailed above, according to the present invention, it is possible to prevent contact wear between the end of the outer peripheral surface of the lever shaft and the sliding surface facing the end of the outer peripheral surface. It has this excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway view showing an adjusting lever mounting structure showing one embodiment of this invention, and FIGS. 2 and 3 are adjusting lever mounting structures showing another embodiment of this invention. FIG. 3 is a partially cutaway view of the structure. 4 to 6 are drawings showing a conventional example, in which FIG. 4 is an explanatory diagram explaining the action of the adjusting lever, FIG. 5 is a partially cutaway view of the adjusting lever mounting structure, and FIG. FIG. 3 is a partially cutaway view of the adjusting lever mounting structure in a state where the adjusting lever is rotated. In the figure, 1 is the AJ lever as a rotating lever, 4 is the AJ lever shaft as a lever shaft, 4a is the upper end of the outer peripheral surface, 6 is the housing, 6a is the boss part, and 7a is the upper end of the inner surface as the sliding surface. , α is the fine gap, and β is the enlarged gap.

Claims (1)

[Claims] 1. The lever shaft is rotatably supported by a boss formed in the housing, and there is a fine groove between the outer circumferential surface of the lever shaft and the sliding surface facing the outer circumferential surface that allows the lever shaft to rotate. In a rotating lever mounting structure in which a gap is provided and a rotating lever is fixed at the end of the lever shaft, there is a space between an outer circumferential surface end of the lever shaft and a sliding surface opposite to the outer circumferential surface end. A mounting structure for a rotating lever, characterized in that an enlarged gap wider than the minute gap is provided.