JPS59128970A - Fuel injection pump drive unit - Google Patents

Abstract

PURPOSE:To adjust fuel injection timing by displacing a sleeve in the rotary direction of a fuel cam in relation to the center of the fuel cam. CONSTITUTION:A sleeve 5 is inserted between a cam upper case 6 and a slide cylinder 3, and the inner diameter center 7 and the outer diameter center 8 are located eccentrically. A cam roller 2 drives a fuel injection pump plunger 4 through the slide cylinder 3, and the fuel is injected into the cylinder with a fuel injection valve. Since the centers of the inner and outer diameters are eccentrically located, the cam roller center is moved in the rotary direction of a fuel cam 1 by rotating the sleeve, thus resulting in a change of the fuel injection timing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection pump and drive device for an internal combustion engine.

Conventional 1 Indicated mean effective pressure Pm'i (!: Maximum pressure Pm
The relationship with ax is upward sloping to the right as shown by the solid line in FIG.

As shown by the broken line in the figure, a method has been used in which the maximum pressure Pmax in the normal use area a is increased to lower the fuel consumption rate in the normal use area a.

In order to set the maximum pressure Pmax as indicated by the broken line in FIG. 5, the fuel injection timing in the normal use area a is made earlier than in the high load area.

In an engine using a jerk type fuel injection pump, the top surface of the input plunger 01 is formed into a chevron shape as shown in FIG. 6, and the maximum pressure Pmax is limited as shown by the broken line in FIG.

In the jerk type fuel injection pump, the fuel inlet o2 is the sixth
Fuel is discharged while the striped part of the plunger 01 in the figure remains grounded. Therefore, if the striped portion is made upwardly convex, the fuel injection timing at that portion will be earlier. The amount of fuel discharged is determined by the width of the striped portion in the vertical direction. This width and the shape of the top surface of the plunger determine the amount of fuel discharged per stroke and the timing of fuel injection. In addition,
In Fig. 6, 03 indicates the discharge valve, b indicates fuel increase (direction of turning the planar wheel), and c indicates the operation of the plunger.

However, the conventional method described above has the following drawbacks.

(1) Since the fuel discharge amount and fuel injection timing are determined by the plant, if the heat generation report for the fuel volume differs, the fuel injection timing will change even if the average effective pressure Pn1 is the same. For this reason, there is a difference in performance between when A heavy oil is used and when C heavy oil is used.

(Since the injection pressure mode for each type that affects 2-inch plowing is determined by the speed of the plant, that is, the groin file of the burnt cam, IW, (f = 4 cam has an ideal range of use. Since the positions of the fuel cam and roller are constant, the speed curve of the plunger relative to the crank angle is constant as shown in Figure 7.If the timing of the start of injection is changed, the usage range of the fuel cam changes. This deviates from the ideal fuel cam usage range d.

A indicates the start of injection and 2 ports indicate the injection path.

(3) When derating is used to lower the regular output in order to lower the rate of accommodation charges, the fuel consumption rate is lowered by increasing the maximum pressure Pmax in the zone where the average effective pressure Pm1 is low. However, as mentioned above, the bonito material injection timing with respect to the fuel discharge per stroke (proportional to the average effective pressure Pmi) is determined by the plunger.

Having to equip a different plunger for each derating specification is disadvantageous in terms of parts manufacturing and service.

The object of the present invention is to provide a fuel injection pump drive device which eliminates the above-mentioned drawbacks, and is characterized by:
In a jerk-type fuel injection bong, which has a sliding cylinder that pivots a cam roller that is linked to a fuel cam and reciprocates a plunger, and a sleeve that is inserted between the sliding cylinder and the cam upper case, the inner diameter and outer diameter are uneven. The sleeve is formed around the fuel cam and rotates to displace the center relative to the center of the fuel cam in the direction of rotation of the fuel cam to adjust the fuel injection timing.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a fuel injection pump 1 driving device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line B-B in FIG. 1, and FIG. BB arrow sectional view when rotated by 180 degrees.

FIG. 4 is a sectional view taken along the line A-A in FIG. 1.

In the figure, 1 is a fuel cam and 2 is a cam roller.

3 is a flat cylinder that supports the cam roller 2, and the other end is a flat cylinder.
It is in contact with the end of the lantern 4. A sleeve 5 is fitted between the cam upper case 6 and the bevel cylinder, and the center 7 of the inner diameter and the center 8 of the outer diameter are eccentric. 9 is the combustion engine main body, and 10 is a rotation stopper.

The operation in the case of the above configuration will be described.

The fuel cam 1 is driven by a crank q] 11 via a gear or the like. The cam 1 drives the cam roller 2 up and down. The cam roller 2 moves the fuel injection valve 2 and the plunger plunger 4 through the slide tube 3, and the fuel injection valve (not shown)
The fuel is injected into the cylinder.

The tube cylinder 3 is housed in a sleeve 5 whose inner and outer diameter centers are eccentric. The sleeve 5 is rotated according to a timing control (not shown). Since the centers of the inner and outer diameters of the sleeve 5 are eccentric, by rotating the sleeve the center of the cam roller moves in the direction of rotation of the fuel cam 1 and also in the direction of the cam axis, but this is not important from a functional point of view. Injection timing changes.

The above case has the following effects.

(1) The fuel injection timing can be determined regardless of the fuel discharge amount, so the above-mentioned disadvantages of the conventional method (1)
, (2) and (3) are resolved.

(2) Since an eccentric sleeve is used to change the timing, any timing can be selected.

(3) Since an eccentric sleeve is used, the timing can be changed continuously during operation.

(4) The deviation Δ of the center of the inner and outer diameters of the sleeve is not so large1117. In this case, all or most of the torque T that causes the sleeve to rotate during the Zydo thrust F (see Figure 1) is absorbed by the friction rayon on the outer diameter of the sleeve, so the timing adjustment mechanism (mechanism that rotates the sleeve)
No large force is applied to the

[Brief explanation of drawings]

FIG. 1 shows an example of a natural injection pump 1 according to the present invention.
1 shows the drive device] 1: [Top view, Figure 2 is B in Figure 1
3 is a sectional view taken along the line B-B when the sleeve is rotated by 180° in FIG. 2; FIG. Figure 4 is a cross-sectional view taken along the line A-A in Figure 1, Figure 5 is a diagram showing the relationship between the maximum internal pressure and the indicated average effective pressure, and Figure 6 is the conventional Noyak method. FIG. 7 is an explanatory diagram showing the main parts of the fuel injection pump, and FIG. 7 is an explanatory diagram showing the relationship between the fuel cam speed and the crank angle. 1...Fuel cam, 2...Cam roller, 3...Sliding tube. 4. Plants, 5. Sleeves, 6. Upper cam case. Urank re-piece 7

Claims (1)

[Claims] 1. A jerk-type j that has a sleeve that is fitted between the same bevel cylinder and the cam upper case that pivotally supports the cam roller that is linked to the fuel cam and reciprocates the blanker.
li"l'≦Fuel injection 2) When the inner diameter and outer diameter are uneven) A fuel injection pump operating device characterized by having a sleeve for adjusting timing.