JPS6245076Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a distribution type fuel injection pump for diesel engines, and in particular, it makes a difference in the injection amount of the fuel injection nozzle of each cylinder or of two fuel injection nozzles provided in one cylinder. The present invention also relates to an injection amount control device for a distribution type fuel injection pump that is capable of controlling the difference therebetween.

In a conventional distributed fuel injection pump, the amount of oil sent to the fuel injection nozzles of each cylinder is equal under certain engine operating conditions.

Therefore, when performing cylinder reduction operation to reduce noise and harmful exhaust gases, when each cylinder has a different combustion chamber shape, or when one cylinder is equipped with two fuel injection nozzles to perform pilot injection. In some cases, when differentiating the injection timing of the injection amount of each fuel injection nozzle, it is difficult to meet the requirements with a single distribution type fuel injection pump, and it is usually necessary to use two or more pumps. There was a problem.

Furthermore, as shown in Japanese Utility Model Application Publication No. 49-83422, it is known that the notch of the cut-off barrel is sloped, but this has a single injection nozzle and the cut-off barrel is It does not rotate in the circumferential direction.

The present invention was developed by focusing on such conventional problems, and it is a method that brings about a difference in the injection amount of the fuel injection nozzle of each cylinder or two fuel injection nozzles provided in one cylinder, and also eliminates the difference. An object of the present invention is to provide an injection amount control device for a distribution type fuel injection pump that can control the injection amount.

The present invention will be explained below based on the drawings.

1 to 4 show an embodiment of the present invention. In this embodiment, each cylinder is equipped with two main and sub fuel injection nozzles, and the injection amount of the main and sub nozzles can be controlled separately depending on the engine operating conditions (load). It is something.

In the figure, a main plunger 3 is slidably inserted into a sliding hole 2 formed in a pump housing (distribution head portion) 1, and the main plunger 3 is caused to reciprocate and rotate by means not shown.

When the main plunger 3 is in the suction stroke moving to the left in the figure, the fuel in the pump chamber 4 supplied by the feed pump (not shown) is transferred from the main suction passage 5 to the suction groove 6 of the main plunger 3 (the number of cylinders in the circumferential direction). ) is sucked into the main pressure chamber 7 through the same number of channels. When the main plunger 3 moves to the right while rotating and moves to the pressure feeding stroke, the main suction passage 5
and the suction groove 6 are separated, and the fuel in the main pressure chamber 7 is compressed and flows from the through hole 8 bored in the axial direction of the main plunger 3 through the distribution groove 9 to the main discharge passage 10.
(A number corresponding to the number of cylinders are equally spaced in the circumferential direction.) The fuel is delivered to the main nozzle via a main delivery valve (not shown) and injected into the cylinders.
In this way, fuel is injected into each cylinder in a predetermined order as the main plunger 3 reciprocates and rotates.

A control sleeve 12 is slidably inserted into the base of the main plunger 3 on the side of the pump chamber 4, and a main cut-off port 13, which is opened in the base and communicates with the through hole 8, is inserted into the control sleeve 12. When it comes off the circumferential surface and opens into the pump chamber 4, the fuel leaks into the pump chamber 4, so the delivery to the main discharge passage 10 side is stopped and injection ends.
Therefore, by adjusting the position of the control sleeve 12, the end of injection can be changed, that is, the injection amount can be controlled.
4 is engaged, and if the control sleeve 12 is moved to the right in the figure by this lever 14, the injection amount will increase, and if it is moved to the left, the injection amount will be decreased.

On the other hand, a series of sliding holes 15 having a smaller diameter than the sliding hole 2 are formed on the tip side of the sliding hole 2.
A small-diameter sub-plunger 16 formed in series with the distal end side of the main plunger 3 is slidably inserted into the main plunger 3,
A sub-pressure chamber 17 is provided on the tip side of the sub-plunger 16.
has been formed. In addition, this sub-plunger 16 has an appropriate number of suction grooves 1 as well as the main plunger 3.
8, and an auxiliary suction passage 21 branched from the middle of the main suction passage 5 is opened on the inner circumferential surface of the sliding hole 15 so as to face the suction groove 18 of the auxiliary plunger 16. The through hole 22 of the sub plunger 16 is extended to the main plunger 3 side, and the sliding hole 22 is extended to the main plunger 3 side.
It communicates with distribution grooves 24 opened at positions corresponding to sub-discharge passages 23 (connected to sub-nozzles via sub-delivery valves (not shown)) formed at equal intervals on the inner circumferential surface of the cylinder in a number corresponding to the number of cylinders. are doing. Further, this through hole 22 communicates with a sub cut-off port 25 opened at the same position in the axial direction as the main cut-off port 13 .

Therefore, during the pumping stroke of the main plunger 3,
Fuel is also pumped by the sub-plunger 16 and injected into the cylinder from the sub-nozzle. However, the injection by the auxiliary nozzle is performed in advance of the next cylinder in which the injection by the main nozzle is performed.

Here, a steeply sloped portion 26a and a gently sloped portion 26b are formed on the end surface of the control sleeve 12 in accordance with the number of cylinders in accordance with the locus of movement of the main and sub cut-off ports 13 and 25 accompanying the movement of the plungers 3 and 16. The number is equally spaced.

Then, in order to rotate the control sleeve 12 according to the engine operating conditions, in this example, the load,
An inclined guide groove 27 is formed on the outer peripheral surface of the control sleeve 12, and a fixing pin 28 protruding from the inner wall of the pump housing 1 is inserted into the inclined guide groove 27, so that the control sleeve 12 can be moved in the axial direction by the control lever 14. Accordingly, the control sleeve 12 is rotated by the cooperation of the inclined guide groove 27 and the fixing pin 28. That is, the control sleeve 12 is controlled by the control lever 14, the inclined guide groove 27, and the fixing pin 28.
It constitutes a mechanism that rotates in the circumferential direction. still,
The engagement groove 29 of the control sleeve 12 with which the tip of the lever 14 engages is formed to be elongated in the circumferential direction.

According to this configuration, when the control sleeve 12 is moved by the lever 14, for example, to the right (in the injection amount increasing direction) in FIG. The rotation is given counterclockwise in Figure 3, and to the left in the developed view of Figure 4. Here, regarding the main cut-off port 13, the steeply sloped portion 26a
A cut-off action is performed when exposed from the
A cut-off effect is performed when exposed from the slanted portions 26a and 26b, and since the inclinations of these slanted portions 26a and 26b are different, the injection amount of the nozzle of the main width can be adjusted depending on the rotation angle of the control sleeve 12 as shown in FIG. will change.

In this embodiment, the control sleeve 12
The inclined portions 26a, 26 are formed by protruding the end surfaces on the inner circumference side.
b is formed, but it may be formed by cutting out the end surface on the inner peripheral side.

FIG. 6 shows another embodiment.

In this embodiment, main and sub cut-off port 1
Auxiliary cut-off ports 31 and 32 are formed in series with ports 3 and 25, respectively. These auxiliary cut-off ports 31, 32 are formed so as to open into the pump chamber 4 when the plunger 3 is at the bottom dead center (leftmost position), and during a predetermined stroke at the beginning of the pumping stroke, that is, when the plunger 3 is at the bottom dead center (leftmost position) 3 in the right direction, it continues to open until it enters the inner peripheral part of the control sleeve 12 and is closed. and,
Slanted portions 26a and 26b are formed on the end surface of the control sleeve 12 in correspondence with the movement loci of these auxiliary cut-off ports 31 and 32.

With this configuration, the beginning of the injection can be varied by rotating the control sleeve 12, thereby making it possible to control the injection amount.

In addition, in these examples, only the case where one cylinder has two fuel injection nozzles and the amount of distribution to the main and sub nozzles is variable is shown, but the amount of distribution to the fuel injection nozzles of each cylinder is In other words, the number of plungers, pressure chambers, cut-off ports, etc. is one, and the end face of the control sleeve is formed with the same number of inclined portions as the number of cylinders, and the slopes of each inclined portion are made to be different from each other. In addition, a mechanism for rotating the control sleeve in the circumferential direction depending on engine operating conditions may be provided.

As explained above, according to the present invention, by appropriately selecting the inclination angle of the end face of the control sleeve, the fuel injection nozzle of each cylinder or a pair of fuel injection nozzles provided in one cylinder can be injected according to the engine operating conditions. The effect is that the injection amount can be controlled for each nozzle, and that this can be achieved with a single pump.

[Brief description of the drawings]

Fig. 1 is a vertical cross-sectional view of essential parts of a distribution type fuel injection pump showing an embodiment of the present invention, Figs. 2 and 3 are front and right side views of the control sleeve of the above, and Fig. 4 is a longitudinal sectional view of the same. FIG. 5 is a developed view of the inclined portion of the control sleeve, FIG. 5 is a fuel injection amount characteristic diagram similar to the above, and FIG. 6 is a longitudinal cross-sectional view of a main part showing another embodiment. 3, 16... Plunger, 12... Control sleeve, 13, 25... Cut-off port,
26a, 26b... Slanted portion, 27... Slanted guide groove, 28... Fixed pin, 31, 32... Auxiliary cut-off port.

Claims (1)

[Scope of utility model registration request] A cut-off port is provided on the outer circumferential surface of the base of the plunger, which performs reciprocating and rotational movement to suction and pressure feed and distribute fuel, and a control sleeve that is slidably inserted into the base is moved in the axial direction. In a distribution type fuel injection pump in which at least one of the end of injection and the beginning of injection is controlled by displacing the position of the end face of the control sleeve relative to the locus of movement of the cut-off port accompanying the movement of the cut-off port, the end face of the control sleeve is Inclined at each predetermined angle in the circumferential direction,
An injection amount control device for a distribution type fuel injection pump, characterized in that the inclination of at least part of the control sleeve is made different from that of the other part, and a mechanism is provided that rotates the control sleeve in the circumferential direction depending on engine operating conditions.