JPH021485Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection device in which fuel injection timing can be adjusted by moving a sleeve fitted over a plunger.

In order to cope with recent strict exhaust gas regulations, there has been a demand to freely change the injection timing of fuel injection devices depending on rotation and load.
However, with conventional timers, the injection timing only changes depending on the pump rotation speed.
It cannot be changed depending on the load.

The present invention is a fuel injection device that can control the injection amount and injection timing using a control sleeve by controlling the movement of a single adjustment rod, and can also mechanically control the injection timing according to the load (injection amount). The purpose is to provide.

The present invention will be explained below based on illustrated embodiments.

In FIG. 1, the plunger 1 has an axial hole 8 connecting the plunger chamber 9 and the fuel suction chamber 10.
and a radial hole 8a, and a width across flats 11 is provided to prevent the plunger 1 from rotating, and this width across flats engages with a lower seat 12. Furthermore, the plunger 1 is tightly fitted with the cylinders 6, 7 and the control sleeve 2. The cylinder 6 is tightened to the housing 24 by a bolt 13 and a nut 14, and the cylinder 7 is pressed downward by the fuel spill shield 6a. The control sleeve 2 can rotate and move up and down relative to the plunger 1, has a lead 3a for defining the start of injection and a lead 3b for defining the end of injection, and has a hole 16 into which the sleeve adjustment pin 15 is tightly fitted. have The intermediate sleeve 25 with the sleeve adjustment pin 15 has a position adjustment hole 19, and the hole 2 of the adjustment rod 4
After inserting the rod 26 into the hole 19 and adjusting the position of the adjustment rod 4 and the intermediate sleeve 25, both 4, 2
5 is fixed with a screw 21.

In the above configuration, when the tappet 22 is raised against the plunger spring 5 by a cam (not shown), the plunger 1 is raised, and the radial hole 8a of the plunger 1 is opened by the control sleeve 2 as shown in FIG. When closed, the fuel in the plunger chamber 9 is pressurized, pushes up the valve 23 and is directed to a nozzle, not shown. When the plunger 1 further rises and the radial hole 8a touches the end-of-injection lead 3b of the control sleeve 2 as shown in FIG. The fuel is discharged into the suction chamber 10, and the pumping of the fuel ends.

To adjust the fuel injection amount, the control sleeve 2 is rotated by moving the adjustment rod 4 in a direction perpendicular to the axial direction of the plunger 1 using a governor (not shown), and the control sleeve 2 is rotated between the radial hole 8a of the plunger (1) and the control sleeve. 2, change the relative position with the injection end regulation lead 3b,
This is done by changing the fuel pumping stroke.

On the other hand, to adjust the injection timing, the control sleeve 2 is moved up and down by rotating the adjustment rod 4, and the injection start regulation lead 3a of the control sleeve 2 is adjusted.
This is done by changing the timing at which the plunger closes the radial hole 8a.

Next, the injection timing adjustment mechanism will be explained with reference to FIGS. 4 to 6. The intermediate sleeve 25 is one more
The adjustment pin 30 has a ball attached to its tip and tightly fits into the elongated hole 32 of the link 31, but it can slide in the long direction of the elongated hole 32. It's summery. The link 31 is rotatable about a fulcrum 33, and a connecting rod 34 is rotatably attached by a pin 35.
The push rod 36, which is slidably attached to the column 38, is pressed against the link 31 by a spring 37 with an initial spring force. stoppa 39
regulates the amount of rotation of the link 31. Connection rod 34
is in contact with the leg portion 43 of the weight 42 which is attached to the weight rotating shaft 40 with a pin 41. The weight rotating shaft 40 is fixed to a gear 44, which is connected to a gear 4 attached to a pump drive shaft 45.
6 can transmit rotational force. Note that the elongated hole 32 is designed so that when the adjustment rod 4 is moved in the axial direction by the governor, the adjustment rod 4 is automatically rotated at the same time.
is formed to be inclined with respect to the moving direction of the adjustment rod 4.

Next, the operation of this injection timing adjustment mechanism will be explained.
When the pump rotates, the flyweight 42 tries to open, but since the link 31 is pushed by the spring 37 via the push rod 36, the flyweight 42 will not open until the initial load of the spring 31 is overcome. constant, and the position of the control sleeve 2 relative to the plunger remains constant. As the pump rotation increases, the centrifugal force of the flyweight 42 acts on the spring 37, causing the link 31 to begin to move in the direction of arrow A in Figure 4, and the adjustment rod 4 to move in the direction of arrow B in Figure 4.
direction, and moves the control sleeve 2 downward in FIG. 1 to begin advancing the angle. As the rotation increases, the injection timing is further advanced while the force of the spring 37 and the centrifugal force of the fly weight 42 are maintained in balance. However, when the link 31 comes into contact with the stopper 39, the advance ends.

By such an operation, characteristics as shown by the solid line in FIG. 7 can be obtained. Here, since the elongated hole 32 of the link 31 is inclined with respect to the moving direction of the adjustment rod 4, when the adjustment rod 4 is moved to control the injection amount, the adjustment pin 30 slides inside the elongated hole 32. The intermediate sleeve 25 and the adjustment rod 4 rotate, so that the injection timing is controlled also in accordance with the load, as illustrated by broken lines and dashed lines in FIG.

Although the flyweight 42 was used in the above embodiment, a generator may be attached to the flyweight shaft 40 and the connecting rod 34 may be moved by a linear solenoid.

Further, although the elongated hole 32 is provided in the link 31, an elongated hole may be provided in the adjustment rod 4 or the intermediate sleeve 25, and the adjustment pin 30 may be provided in the link 31. moreover,
The elongated hole 32 may be either straight or curved.

Furthermore, it is also possible to use a two-stage or three-stage spring as the spring 37 and change the spring constant by changing the stroke of the push rod 36. Also, by changing the initial spring force of the spring 37, the rotation speed at the beginning of the advance angle can be adjusted. It is also possible to change the angle, and by changing the protrusion amount of the stopper 39, the maximum advance angle amount can also be adjusted.

As is clear from the above explanation, according to the present invention, the injection amount can be controlled by the axial movement of one adjustment rod, and the guide mechanism is linked to the axial movement of the adjustment rod. Since the adjustment rod mechanically rotates, the injection timing can be automatically controlled according to the load (injection amount). Furthermore, in the present invention, since the injection amount is adjusted by moving the control sleeve, the structure of the pump is simpler than that of the conventional type in which a plunger is rotated. Accordingly, the space for the plunger spring can be widened, making it possible to use a spring with a large spring force, thereby suppressing the jumping of the tappet and allowing the pump to rotate at high speed.
Further, the force for rotating the control sleeve is smaller than that for rotating a conventional plunger, and the response is improved, making it easier to prevent hunting.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention;
Figures 3 and 3 are for explaining the operation, Figures 4-
Fig. 6 shows the injection timing control mechanism, Fig. 4 is a perspective view of its main parts, Fig. 5 is a schematic diagram of the flyweight section, Fig. 6 is a configuration diagram of the rotary drive section, and Fig. 7 is a schematic diagram of the flyweight section.
The figure is a characteristic diagram. 1...Plunger, 2...Control sleeve, 3
a, 3b... Lead,... Axial hole, 8a... Radial hole, 9... Plunger chamber, 10... Fuel suction chamber, 30, 32... Pin and elongated hole forming the main part of the guide mechanism.

Claims (1)

[Scope of utility model registration request] A plunger chamber is provided at the tip of the reciprocating plunger, and the plunger chamber can communicate with the fuel suction chamber through an axial hole and a radial hole in the plunger, and the radial hole is opened and closed by a control sleeve inserted into the plunger. In a device that controls fuel injection timing by displacement of a control sleeve in the axial direction of a plunger, the control sleeve is rotatable relative to the plunger, and the control sleeve has an injection start regulation lead and an injection end regulation lead. axially moving the adjusting rod by changing the distance between them along the circumferential direction of the control sleeve and utilizing the axial movement and rotation of one adjusting rod engaged with the control sleeve. to adjust the fuel injection amount by rotating the control sleeve in the circumferential direction of the plunger, and
The control sleeve is moved in the axial direction of the plunger by rotating the adjustment rod by a guide mechanism that mechanically rotates the adjustment rod in conjunction with the axial movement of the adjustment rod. A fuel injection device for an internal combustion engine, characterized in that injection timing is adjusted.