JPS6329175Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to the structure of a unit injector in which a fuel injection pump and a fuel injection valve of a diesel engine are integrated and fixed to a cylinder head.

(b) Prior Art A unit injector is a compact unit that replaces the fuel injection pump and fuel injection valve, which are separate parts in a conventional diesel engine, and is structurally complex, especially when assembled. The disadvantage of this method was that it became even more complicated because two precision devices were integrated into one.

Conventional unit injectors are shown in Figures 3 and 4.
As shown in the figure, most of the injection pump and injection valve parts were sandwiched between the injector turbo day and the nozzle nut and assembled by tightening the nozzle nut. After tightening, the accuracy in the layer direction varies depending on the degree of tightening. There was a problem that it was difficult to output.

(c) Problems to be solved by the invention In the invention, the check valve guide is integrally constructed with a unit injector, and the partition between the upper injection pump part and the lower injection valve part is the check valve guide 6d. Furthermore, by assembling from the top and bottom, errors in the layer direction that occur during assembly and tightening are eliminated.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

The middle part of the cylindrical engine turbo day 6 is blocked by a check valve guide 6d, the upper part is a fuel injection pump chamber, and the lower part is a nozzle spring 1.
3, a plate-shaped check valve 9 is placed on the upper surface of the check valve guide 6d, and a space is opened in which the check valve 9 can move up and down. A barrel 5 is placed on the check valve seat 8, and a barrel holder 7 placed on the barrel 5 is screwed onto the injector body 6.

(E) Embodiment The purpose of the present invention is as described above, and the structure of the present invention will be explained based on the structure of the embodiment shown in the attached drawings.

FIG. 1 is a side sectional view of the 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
A fastening fitting 23 is engaged with b, and the fastening fitting is fastened to the cylinder head 22 with a long bolt 23. With the injector body 6 in the center, it can be disassembled and assembled from two directions: from below and from above.

From below, the nozzle spring 13 and nozzle spring seat 15 are covered with a valve stop spacer 27, and the nozzle body 19 in which the nozzle valve 18 is fitted is placed below the nozzle spring 13 and the nozzle spring seat 15. 6 is screwed on.

A check valve 9 and a check valve seat 8 are arranged from above the injector body 6, and after a spill deflector 10 is fixed with a spring pin 11, a barrel 5 is placed and screwed with a barrel holder 7.

A check valve guide 6d is integrally constructed at the upper and lower branch portions of the injector body, and serves as a partition between the injection pump section and the injection valve section and as a guide for the check valve 9.

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 position where the groove 1d and the scored line 6h of the notch end 6k of the injector turbo day 6 match is when the tip of the plunger 3 is out of the suction port 5a and before the compression stroke starts. It shows.

A control lever 2 is directly connected to a protrusion of the plunger 4 from the tappet 1 by a parallel 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 opens in a fan shape at notched ends 1c, from which a control lever 2 protrudes and is rotatable. An adjustment device is provided at the portion where the control lever 2 contacts the notch 1c of the tappet 1 so that the injection amount of the unit injectors of all cylinders becomes constant.

Further, a countersink hole 1b is provided in the horseshoe-shaped portion, and a tapepet plate 21 is fitted into the countersink hole portion. A rocker arm linked to a camshaft pushes the top 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 tapepet 1 is provided with a vertical groove 1a, and the vertical groove 1
An eccentric pin 25 is fitted into a. Eccentric pin 25
is fixed to a rotating plate 25a with an elongated hole, and by loosening the bolt 26 and rotating the rotating plate, the tappet 1 is rotated via the eccentric pin 25, and the movement of the control lever 2 is controlled. The width is regulated by the notched ends 1c, 1c of the tappet 1 to adjust the non-uniformity of the injection amount for each unit injector in the case of multiple cylinders. That is, the injection amount of each unit injector in a multi-cylinder system is adjusted during assembly so that the injection amount of each unit injector is constant at the location where the control lever 2 contacts the notched ends 1c, 1c of the tappet 1.

Fuel is drawn through the oil passage 22a in the cylinder head and enters the oil sump 6a through the hole in the injector body. A spill deflector 10 is fixed to the surface of the oil reservoir 6a facing the suction hole 5a by a spring pin 11 to prevent invasion by spills.

The fuel is then sucked in through the suction port 5a as the plunger of the cylinder inside the barrel 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 plunger 3
starts pumping fuel from the part where the tip of the inlet 5a deviates from the diameter of the inlet hole 5a, and the inclined notch 3a
Pumping ends when the diameter of a is reached. After that, even if the plunger is lowered, the fuel in the cylinder escapes from the oil passage 3b extending through the plunger through the inclined 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, thereby adjusting the pumping time and thereby adjusting the injection amount.

The pressure-fed fuel flows from the check valve 9 to the oil line 6.
c, passes through the valve stop spacer 27, enters the nozzle body 19, and when the opening pressure reaches the opening pressure or higher, the nozzle valve 18 is stopped by the nozzle spring 13.
The fuel is pushed up against the pressure and 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; 16 is a parallel pin for determining the position of the injector turbo day 6, check valve seat 8, and barrel 5; 14 is a pressure adjustment plate; 12 is an O-ring.

FIG. 3 is a side sectional view of a conventional unit injector, and FIG. 4 is an enlarged sectional view of the check valve guide 6b.

In a conventional unit injector, the injector turbo body and the check valve guide are located at separate positions, and the check valve guide and injector turbo body cannot be integrated.
For this purpose, the check valve guide 6d is constructed by inserting the nozzle body 19, nozzle spring case 31, etc. into the nozzle nut 20 and tightening the nozzle nut 20.

With this configuration, both the injection valve and the injection pump had to be assembled in one direction from below, making assembly difficult and difficult to achieve accuracy.

In particular, with the conventional type, as shown in Fig. 3, unless the accuracy of the parallelism of the upper and lower surfaces of the nozzle body 19, nozzle spring case 31, check valve guide 6d, and barrel 5 is significantly improved, oil leaks and malfunctions may occur. It was happening.

30 is a pinion for adjusting the injection amount, and 29 is a rack for adjusting the injection amount that is interlocked with the governor device. Further, in the present invention, the nozzle spring case of the nozzle spring 13 is also integrally constructed with the injector turbo day, which is useful for reducing the number of parts and improving assembly accuracy.

(f) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, in a conventional unit injector, the nozzle body 19, nozzle spring case 31, check valve guide 6d, and barrel 5 are all separated and inserted in order into the injector body 6, and then stacked. Since it was fixed in the mounted state, the accuracy of the parallelism of the upper and lower surfaces was
Unless significant improvements were made, oil leaks and malfunctions would occur.

On the other hand, in the present invention, the check valve guide 6d on which the check valve 9 is placed is constructed integrally with the engine engine turbo day 6, and the fuel injection valve parts are configured to be inserted from below. Since the check valve 9 is not stacked with the seat 8 or the barrel 5, the check valve 9 is placed on the check valve guide 6d that is integrally formed with the injector body 6, so that it is placed in an accurate position. It is.

Second, since the check valve seat 8 is first placed on the mounting step of the check valve seat 8 that is precisely positioned on the injector body 6, the surface of the check valve seat 8 that the check valve 9 is attracted to is Since the barrel 5 placed on the check valve seat 8 is overlapped with the check valve seat 8 in only two stages, it is possible to accurately locate the barrel 5. .

With this configuration, it was possible to eliminate the problems of oil leakage and malfunction, which are the disadvantages of unit injectors.

Thirdly, it was possible to eliminate the instability of pump pressure and variation in injection amount due to deviations in accuracy in the layer direction during assembly and tightening, which occurred with the conventional configuration.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of the unit injector of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a side sectional view of a conventional unit injector, and Fig. 4 is an enlarged view of the check valve guide portion of the present invention. FIG. 1... Tappet, 2... Control lever,
3... Plunger, 5... Barrel, 6... Injector body, 6d... Check valve guide, 7... Valve holder, 9... Check valve, 10... Spill deflector, 13... Nozzle spring, 18... ...Nozzle valve, 19...
Nozzle body, 20... Nozzle nut, 21...
Tappet plate, 23... tightening metal fittings.

Claims (1)

[Scope of utility model registration request] The middle part of the cylindrical engine turbo day 6 is blocked by a check valve guide 6d, the upper part is a fuel injection pump chamber, and the lower part is a nozzle spring 1.
3, a plate-shaped check valve 9 is placed on the upper surface of the check valve guide 6d, and a space is opened in which the check valve 9 can move up and down. A unit injector for an internal combustion engine, characterized in that a barrel 5 is placed on the check valve seat 8, and a barrel holder 7 placed on the barrel 5 is screwed to an injector body 6. .