JPH0214989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a unit injector that integrates an injection pump and an injection valve for a diesel engine.

(b) Prior art Regarding the technology related to the unit injector of internal combustion engines, there is
Techniques such as those disclosed in Japanese Patent Application Laid-open No. 160918/1983 are known.

(c) Problems to be solved by the invention However, in both of the above two cited examples, the nozzle spring, nozzle body, nozzle valve, and barrel are tightened together in series from below by a nozzle nut. It was configured.

Therefore, the clamping force on the barrel side and the clamping force on the nozzle body side were in a relationship of action and reaction in which the same clamping force acts on each other.

As a result, the nozzle nut requires a small tightening force for the nozzle body, but the barrel requires a large tightening force.
A force greater than that required to tighten the barrel is required, and the nozzle body, nozzle valve, and
Since the nozzle nut was made stronger, this led to the overall size of the unit injector.

Furthermore, since the partition wall W is not configured between the barrel and the nozzle valve, the assembly accuracy of the parts that are tightened in series, such as the barrel 5, the nozzle spring, the nozzle body, and the nozzle valve, is determined by the cumulative error of each part. Therefore, it was necessary to increase the processing accuracy of each part.

Similarly, since a high level of assembly precision is required, productivity is low.

In particular, if the parallelism of the clamping surfaces of the barrel or nozzle body is not accurate, oil leaks from the gaps created in the clamping surfaces, and in order to eliminate this oil leakage, it is necessary to increase the clamping force. A vicious cycle was occurring.

In order to improve these points, the present invention provides a bulkhead W in the injector body 6 constituting the case of the unit injector, and the barrel 5 is fastened to the bulkhead W by a barrel holder 7 from above, and conversely, the nozzle body 19 is attached to the bulkhead. Nozzle nut 2 at the bottom of W
By tightening from below with 0, the assembly system is made separate and solved.

(d) Means for Solving the Problems The objects of the present invention are as described above. Next, the configuration for achieving the objects will be explained.

The nozzle spring 13, nozzle body 19, and nozzle valve 18 arranged at the lower part of the injector turbo day 6 and the barrel 5 arranged at the upper part of the injector turbo day 6 are connected to the injector by each nozzle nut 20 and the barrel holder 7. body 6
They are separately tightened and fixed from opposite sides with respect to the partition wall W installed inside the.

(e) Embodiment The object and structure of the present invention are as described above, and next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is a side sectional view of a unit injector of the present invention, and FIG. 2 is a plan view.

This unit injector is mainly composed of an injector body 6. An ear portion 6b is made to protrude outside the injector body 6, and the ear portion 6b is
b is engaged with a fastening metal fitting 23, and the fastening metal fitting 23 is fastened to the cylinder head 22 with a long bolt 24.

It is constructed so that it can be disassembled and assembled from two directions, from below and above, with the partition wall W of the injector body 6 at the center.

From below the injector body 6, the bulkhead W
Insert the nozzle spring 13 and nozzle spring seat 15, cover with the valve stop spacer 27, and place the nozzle valve 18 under it.
A nozzle body 19 fitted with the nozzle body 19 is arranged, and is screwed onto the injector body 6 from below with a nozzle nut 20.

A check valve seat 8 is arranged from above the injector body 6 toward the partition wall W, and after a spill deflector 10 is fixed with a spring pin 8, a barrel 5 is placed and screwed with a barrel holder 7.

A plunger 3 is inserted into a cylinder hole in a barrel 5, a tappet 1 is passed through the plunger 3, and a plunger spring 4 is received by the tappet 1.

A groove 1d is provided on the outer periphery of the tappet 1, and the portion where the groove 1d and the scored line 6h of the notched end surface of the injector body 6 match is the tip of the plunger that is connected to the suction port 5a.
This indicates that it is time to start the compression stroke.

The control lever 2 is directly connected to the protrusion of the plunger 4 from the tappet 1 by a locking pin 28. An arm of a governor device is engaged with the control lever 2 . The tappet 1 has a horseshoe shape at its upper end, and has fan-shaped openings at cutout ends 1c, from which a control lever 2 protrudes and is rotatable.

Control lever 2 is located in notch 1 of tappet 1.
An adjustment device is provided so that the injection amount of the unit injectors of all cylinders is constant at the portion that contacts c.

Further, a countersink hole 2b is provided in the horse-clamped portion, and a tappet plate 21 is fitted into the countersink hole 1b portion. A rocker arm linked to a camshaft pushes the upper surface of the tapepet plate 21 to push down the plunger. The upward return of the plunger 3 is due to the force of the plunger spring 4.

Further, the tappet 1 is provided with a vertical groove 1a, and an eccentric pin 25 is fitted into the vertical groove 1a.

The eccentric pin 25 is a rotating plate 25a with an elongated hole.
The rotating plate is fixed to the bolt 26.
By loosening and rotating the tappet 1, the tappet 1 rotates via the eccentric pin 25, and the control lever 2
The range of movement of the injector is regulated by the notched ends 1c, 1c of the tappet 1, thereby adjusting the unevenness of the injection amount for each unit injector in the case of multiple cylinders.

That is, the injection amount of each unit injector in the case of a multiple cylinder is adjusted at the time of assembly so that the injection amount is constant at the location where the control lever 2 contacts the notched ends 1c, 1c of the tappet 1.

Fuel is sucked through the oil passage 22a in the cylinder head and enters the oil sump 6a through the hole in the injector body 6. A spill deflector 10 is fixed by a spring 17 to the surface of the oil reservoir 6a facing the suction hole 5a to prevent invasion by spills.

The fuel is then sucked in through the suction port 5a as the plunger 3 inside the barrel 5 retreats upward.
At that time, the check valve 9 is in a sealed state by being adsorbed to the check valve seat to prevent the pushed-out pressure oil from returning.

When the tappet plate 21 is pushed by the rocker arm, the plunger 3 is lowered, and the tip of the plunger 3 starts pumping fuel from the part where it deviates from the diameter of the suction hole 5a, and the inclined notch 3a is inserted into the suction hole 5a.
Pumping ends when the diameter reaches .

After that, even if plunger 3 is lowered, barrel 5
The fuel inside escapes from the plunger's oil passage through the sloping notch.

The timing at which the inclined notch 3a meets the suction hole 5a is changed by rotating the plunger 3 with the control lever 2, and the injection amount is adjusted by adjusting the pumping time.

The pressure-fed fuel flows from the check valve 9 to the oil line 6c.
The nozzle valve 18 is then pushed up against the nozzle spring 13 and is injected into the combustion chamber.

17 is a parallel pin for determining the position of the valve stop spacer 27 and the injector body 6, and 16 is a parallel pin for determining the position of the injector body 6, check valve seat 8, and barrel 5. 14 is a pressure adjustment plate, and 12 is an O-ring.

(F) Effects of the Invention The present invention has been constructed as described above, and has the following effects.

First, the nozzle nut 20 and the barrel holder 7
on opposite sides of the partition wall W,
Since each part is configured as an independent tightening system, it is not necessary to tighten other parts with the tightening force of the barrel that requires the most tightening force, unlike when these were configured as a series of tightening systems as in the past. was gone.

Therefore, the nozzle nut 20 can be set to the minimum necessary size regardless of the tightening force of the barrel holder 7, so there is no need to provide more strength than necessary, and the nozzle nut 20 can be made smaller. .

As a result, the entire unit injector can be downsized, and it has become possible to install the unit injector in small engines, which was previously impossible to do.

Secondly, since the barrel 5 and the injector turbo day 6 can be tightened and fixed separately, the flatness and dimensional tolerance between these tightening surfaces are unrelated to each other, and the bulkhead W of the injector turbo day 6 By improving the machining accuracy of the upper and lower surfaces of the parts shown in FIG. It is something.

Fig. 3: The unit injector can be assembled and disassembled separately from the top and bottom with the partition wall W as the boundary, making it easy to repair and inspect in the event that the inside becomes clogged with dust, etc. .

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a unit injector of the present invention, and FIG. 2 is a plan view thereof. W... Bulkhead, 1... Tappet, 2... Control lever, 3... Plunger, 5... Barrel, 6... Injector body, 7... Barrel holder, 9... Check valve, 10... Spill deflector. , 13... Nozzle spring, 1
8... Nozzle valve, 19... Nozzle body, 2
0... Nozzle nut, 21... Tappet plate, 23... Tightening fitting.

Claims (1)

[Claims] 1. Connect the nozzle spring 13, nozzle body 19, and nozzle valve 18 disposed at the lower part of the injector turbo day 6 and the barrel 5 disposed at the upper part of the injector turbo day 6 by the nozzle nut 20 and barrel holder 7, respectively. A unit injector for an internal combustion engine, characterized in that the unit injector for an internal combustion engine is separately tightened and fixed from opposite sides to a partition wall W provided inside an engine engine body 6.