JPS6259234B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for assembling a control sleeve in a fuel injection pump.

In conventional fuel injection pumps, a control sleeve is assembled from below to a control rack inserted into a pump housing to connect the two. For example, as shown in the drawing of Japanese Utility Model Application Publication No. 52-60518, an assembly hole is formed at the bottom of the fuel injection pump body corresponding to the plunger assembly position provided in the body, and from this hole, a control sleeve etc. was designed to be incorporated into the vertical hole.

For this reason, in order to reduce noise from the fuel injection pump, if the bottom part of the cam chamber where the camshaft is housed was to be integrated with the pump housing and completely blocked, it would be difficult to incorporate the control sleeve. It gets old and can no longer be sealed tightly.

The present invention has been made in view of the above, and includes:
A new assembly in which the tappet, plunger, plunger spring, atspa seat, control sleeve, and plunger barrel are assembled from above into the vertical hole leading to the cam chamber, in other words, the control sleeve can also be easily and securely assembled from above. The purpose is to provide a method for attaching.

The present invention will be described below with reference to an illustrated embodiment.

A pump housing 3 has a cam chamber 2 that accommodates a camshaft 1 driven by an engine (not shown).
A vertical hole 4 leading to the cam chamber 2 is formed. Inside this vertical hole 4, there is a tappet 5, a plunger 10, a plunger spring 6, and a ring-shaped top sheet 7.
is dropped from above, and the stop ring 8 is pressed and fixed into the ring groove 9 on the inner surface of the vertical hole 4 by using the tension of the spring 6 and the guiding action of the upper end inclined surface of the Atsupa sheet 7, thereby locking the Atsupa sheet 7 to prevent it from slipping out. ing.

Further, a control sleeve 11 which is engaged with a plunger 10 whose lower end is locked to the tappet 5 in a non-rotating manner is inserted into the inside of the upper sheet 7 so as to be rotatable with a play δ. Incidentally, a spherical engagement protrusion 12 is fixed to the flange portion of the control sleeve 11.

On the other hand, a control rack 14 having an engagement groove 13 for engaging the protrusion 12 is slidably inserted into the pump housing 3, and the engagement protrusion 12 is inserted into the engagement groove 13. By engaging the control rack 14 and the control sleeve 11, the control rack 14 and the control sleeve 11 are interlocked.

In order to interlock the two, the control rack 14 is slid and held at the maximum position until it comes into contact with a stopper (not shown). Then, after rotating the control sleeve 11 in the same direction, the third
As shown by the two-dot chain line in the figure, by eccentrically moving the control sleeve 11 from the center of the vertical hole 4 to the side opposite to the control rack by the amount of play δ, the spherical engagement protrusion 12 is inserted into the engagement groove 13 and engaged. Match.

After interlocking the control sleeve 11 and the control rack 14 in this manner, the plunger barrel 15 is inserted into the vertical hole 4, and the skirt portion 16 of the plunger barrel 15 is inserted into the control sleeve 14.
1 to hold the control sleeve 11 at the center of the vertical hole 4. Numeral 17 is a nut for tightening and fixing the plunger barrel 15 to the pump housing 3, 18 is a delivery valve to which the plunger barrel 15 is attached, and the plunger 10 moves up and down inside the plunger barrel 15.

That is, in the present invention, the plunger barrel 15 is inserted into the control sleeve 11 after the control sleeve 11 is displaced from the center of the vertical hole 4 and the engagement protrusion 12 is fitted into the engagement groove 13 of the control rack 14. Since the control sleeve 11 is held at the center of the vertical hole 4 by inserting the skirt portion 16, even if the control rack 14 is stroked to the maximum position after assembly,
The engagement protrusion 12 and the engagement groove 13 are held engaged with each other with a depth of the amount of play δ. Therefore, there is no need to assemble the control sleeve 11 into the control rack 14 from below as in the conventional case.
Moreover, since the control sleeve 11 and the control rack 14 are engaged only at the maximum position and only when the control sleeve 11 is deflected, it is necessary to interlock the sleeve and the rack with a predetermined relative phase. can. For this reason, even in the case of a fuel injection pump for a multi-cylinder engine, for example, the phases of each control sleeve can be easily aligned.

Furthermore, when inserting the control sleeve 11 into the vertical hole 4, the height sheet 7, which has been installed and fixed in the vertical hole 4 in advance, acts as a stopper for the control sleeve 11, so that the height between the control sleeve 11 and the control rack 14 is reduced. You can also easily adjust the size.

As explained above, according to the present invention, the tappet, plunger, plunger spring, control sleeve, and plunger barrel can be assembled from above into the vertical hole leading to the cam chamber, so that the bottom of the cam chamber is integrated with the pump housing. It can be completely sealed and reduce noise. Furthermore, by assembling the plunger barrel, the control sleeve and control rack can be reliably engaged and held, and the two can be easily separated by removing the plunger barrel, which greatly improves the workability of attaching and detaching the control sleeve. do. Furthermore, in the assembled state, since the control sleeve rotates using the plunger barrel as a guide, there is no eccentric movement between the control sleeve and the plunger, and the movement of the control rack can be faithfully transmitted to the plunger.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fuel injection pump incorporating a control sleeve by the method of the present invention, FIG. 2 is a sectional view of the same essential parts, and FIG. 3 is a plan view of FIG. 2. DESCRIPTION OF SYMBOLS 1...Camshaft, 2...Cam chamber, 3...Pump housing, 4...Vertical hole, 5...Tappet, 6...Plunger spring, 7...Top seat, 8...Stop ring, 10...Plunger, 11...Control sleeve, 12...Engagement Projection, 13... Engagement groove, 14... Control rack, 15... Plunger barrel, 1
6...Skirt part, δ...Play.

Claims (1)

[Claims] 1. A fuel injection pump in which a tappet, a plunger, a plunger spring, a seat, a control sleeve, and a plunger barrel are assembled from above into a vertical hole leading to a cam chamber,
A play is provided between the outer circumferential surface of the control sleeve that is locked to the plunger and the inner circumferential surface of the Atsupa sheet that locks the upper end of the plunger spring, and the control sleeve is eccentrically moved from the center of the vertical hole by the amount of play. Insert the engagement protrusion of the control sleeve into the engagement groove of the control rack held at the maximum stroke position, and fit the skirt portion of the plunger barrel inserted into the vertical hole into the control sleeve to close the control sleeve. A method for assembling a control sleeve for a fuel injection pump characterized by holding it in the center of a vertical hole.