JPS58158368A - Fuel controlling apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent occurrence of hounting, lowering of the specific fuel consumption and pollution of exhaust gas, by feeding fuel by use of a part of a plurality of fuel injection pumps in an internal-combustion engine of the type in which a fuel injection pump is provided for each cylinder. CONSTITUTION:A plurality of plunger type fuel injection pumps are divided into two groups. In leading the engine operation by use of a first fuel injection pump group, the quantity of injected fuel is increased at a steep angle in a regionIwhile it is increased at a gentle angle in a region II, as shown in the drawing. In leading the engine operation by use of a second fuel injection pump group, on the other hand, the regionIis omitted but the region II is the same as that of the first pump group. With such an arrangement, if all of the pumps are operated, the total quantity of injected fuel is increased continuously with increasing of the angle of rotation. Thus, since similar conditions of combustion to that of high-load operation of an engine can be obtained also at the time of low- load operation, it is enabled to prevent occurrence of hunting, lowering of the specific fuel consumption, pollution of exhaust gas, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-cylinder internal combustion engine using a plunger type fuel injection pump. Regarding the control device, this is to prevent deterioration of exhaust conditions and fuel efficiency during low loads, as well as engine failure due to uneven combustion conditions.

By the way, in a multi-cylinder internal combustion engine in which each cylinder is equipped with a fuel injection pump and the injection amount of each pump is uniformly increased or decreased depending on the load, the amount of fuel supplied to each cylinder is extremely small at low loads. As a result, the combustion condition Ill deteriorates significantly, resulting in poor exhaust and poor fuel efficiency.Especially when using a fuel injection pump that controls the injection amount according to the rotation angle of the plunger, it is difficult to reduce the injection amount. Since the injection amount of each pump tends to be uneven within a range of low engine load, the combustion state of each cylinder becomes uneven at low loads, resulting in quenching.

The present invention is equipped with a plunger type fuel injection pump to cope with the above-mentioned problems in internal combustion engines equipped with a winter cylinder mK. Instead of always denying fuel to the pumps, the injection amount for each pump load is divided into stages so that the required amount of fuel is supplied only by the pumps of some cylinders at low loads. Even when the load is lower than k, the cylinders to which fuel is supplied can obtain the same combustion state as when the load is high, thereby preventing deterioration of exhaust conditions and fuel efficiency, or hunting, etc., at the low load. This is what I asked him to do.

This will be explained below using an example. Fig. 1 (2) shows some cylinders among the plurality of cylinders [equipped plunger type fuel injection pump (first group of pumps), Fig. 1 (b)
1 shows the main parts of the pumps installed in other cylinders (second group pumps), and each shows a part of the 1m and lb plungers that rotate according to the load. Leads 2m, 2b:6f are formed to determine the injection amount, and from the time when the upper edge of the reed closes 3b to the fuel supply port 3 due to the upward movement of the plunger, until the lower edge of the reed opens the opening. Although the configuration is such that the discharge port is 4 m and 4 bllK is pumped, the shape of the lower edge of the lead 2 m and ! In area I of the lead 2a, where the angle of rotation is small, the vertical dimension, which depends on the fuel injection amount by 11!1, increases steeply as the rotation angle increases; When moving to the area ■, the yield dimension decreases stepwise, and then increases again with a gentle slope. In the area I, it is deleted, and in the area U, it has the same shape as the first Darube 0 lead 2a, so the change in the injection amount is 9° in the rotation angle of the pumps of both groups as shown in Figure 3 ( a), (
It will have the characteristics shown in b), and in that case, the amount of drop in the injection amount O of the first group of pumps and the amount of rise of the injection amount of the second group at the time of transition to zone IN IIO are equal. Because of this, the total O fuel injection amount by all the pumps decreases when the rotation angle is continuously increased by 9 degrees as shown by the thick line in FIG. In ζζ, @HA in Figure 4 is the injection amount by the first group O pump,
Range B indicates the amount of injection by the second group O pump, and in this way, in the zone 1% high load area, the required fuel supply amount is divided among 1II, 11, etc. by all the pumps. 11, that is, the first
Since the required amount of fuel is supplied only by the pumps in the group, the amount of fuel supplied to the first group of cylinders is significantly lower than when fuel is evenly supplied to the cylinders even at low loads. There will be more.

Note that in this example, the pump is divided into 29 groups, and the rotation range of the buttenger corresponding to the load is divided into two areas. The range is divided into four areas I'~W
', the plunger leads of each group are 2a'-2d'0jijl! The shape is the 5th WJ
The shape is as shown in (b) to (6), and each pump 10
The injection amount with respect to the rotation angle changes as shown in FIGS. 6(a) to (d)K, and the F-tal injection amount and each rotation area
■ Fuel injection amount O share of each group at '@A'~
D' is in the state shown in the 7th wJK.

As described above, in a multi-cylinder internal combustion engine in which each cylinder is equipped with a plunger-type fuel injection pump, the total fuel supply amount required according to the load can be adjusted by using only some of the pumps in the low load range. In addition, as the number of pumps injecting fuel increases as the load increases, the amount of fuel supplied to the cylinders to which fuel is supplied at low loads is significantly larger than before, which makes it possible to This has the effect of preventing deterioration of combustion conditions due to the very small amount of fuel supplied to the 4X points at low loads, resulting in poor exhaust and deterioration of fuel efficiency, and furthermore, prevention of irregularities in combustion conditions. 0

[Brief explanation of the drawing]

Figure 1 (2), (b) Side view of main parts of the first and second groups of pumps in the first embodiment of the present invention, Figure 2 (a)
, (2) is Okaji (Plunger lead O exploded view of pumps in both groups, Figure 3, etc.), (b) is also in both groups O pump 1) W! Characteristic diagram of injection amount with respect to I dynamic angle,
FIG. 4 is a distribution diagram of the total injection amount according to this embodiment. sIi! Company I (Company) - (6) Company In the second embodiment of the present invention, the plunger leads of the pumps of the 11g groups 1 to 4 are shown in Figures 6 (a) to (6). The 7th percentile of the injection quantity characteristic diagram of the pump is a distribution characteristic diagram of the total injection quantity according to the embodiment.
a, lb...plunger, 2a, 2b, 2m'~2d
'...Lead applicant Tetsu Kubota, ISL Kogyo Co., Ltd. ¥1 (yoshi)

Claims (1)

[Claims] (1) A fuel injection pump whose injection amount is controlled by the rotation of the franchisor is installed in each cylinder, and the plunger of each pump is configured to rotate equally according to the load.Fuel control In the device, each pump is divided into a plurality of groups, the rotation range of the plunger of each pump is divided into the same number of zones, and the shape of the reed is determined to determine the injection amount for the rotation angle of each plunger. In the 10th rotation area corresponding to the lowest load area, only the pumps of the first group inject fuel, and as the rotation area shifts to the high load side, the pumps of the second group and below start injecting fuel sequentially. A fuel control device for an internal combustion engine, characterized in that the total injection amount of each pump O changes continuously according to the load.