JPH0544498A - Fuel injection time regulating device for diesel engine - Google Patents

Abstract

PURPOSE:To enable simple adjustment of fuel injection time per diesel engine. CONSTITUTION:A rotation adjusting tool 8 which is provided with a rotary operation section IU in a pump chamber 1 is fitted by screw in the direction of shaft center A of a fuel injection cam shaft 2. One bearing 6 is supported by the rotation adjusting tool 8, and the other bearing 7 is constituted in the pump chamber 1 in such a way that it can move along the direction of shaft center of cam A. An injection cam gear 3 and an idle gear 4 are constituted in helical gear engaging structure 12. For this reason, when the rotation adjusting tool 8 is rotated by operation means, the injection cam gear 3 moves in the direction of shaft center of cam A, and rotated relatively by helics angle of helical gear for the idle gear 4. Consequently, it is possible to adjust injection time of a fuel injection pump 5 by twisting and rotating the fuel injection cam shaft 2 simply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection timing adjusting device for a diesel engine, which can adjust the injection timing simply and quickly.

[0002]

2. Description of the Related Art As shown in FIG. 1, the basic structure of a diesel engine to which the present invention is applied is that a fuel injection cam shaft 2 is supported in a pump chamber 1 of a diesel engine E via bearings 6 and 7, The crankshaft is operably linked to an injection cam gear 3 fixed to the injection camshaft 2 via an idle gear 4, and the fuel injection camshaft 2 is linked to a fuel injection pump 5 housed in the pump chamber 1 so that fuel can be injected. It is a thing.

Generally, in a diesel engine, the retard angle / advance angle of the fuel injection timing greatly affects the exhaust gas component. For example, when the injection timing is delayed, bluish white smoke or black smoke is likely to be generated, but the combustion time in the combustion chamber is shortened and combustion is still performed in the exhaust pipe, so the maximum combustion temperature is lowered and NOx is reduced. ..

Conventionally, the fuel injection timing of the diesel engine is adjusted by changing the height of the adjuster screw of the fuel injection pump 5 or inserting a shim between the plunger spring seat and the tappet. ..

[0005]

In an actual production line, regardless of the type of diesel engine, the height of the screw and the thickness of the shim are standardized to adjust the injection timing. Of the injection timing becomes large, and for example, in order to reset the engine set to suppress blue-white smoke to the engine for NOx reduction, a complicated operation such as changing the thickness of the shim is required. The present invention is
The technical issue is to simply adjust the fuel injection timing for each individual diesel engine.

[0006]

Means for achieving the above object will be described below with reference to the drawings illustrating an embodiment. That is, according to the present invention, in the diesel engine of the basic structure, the rotation adjusting tool 8 having the rotation operating portion 10 in the pump chamber 1 is screw-fitted in the axial direction A of the fuel injection cam shaft 2, and one bearing 6 Is supported by the rotation adjusting tool 8, the other bearing 7 is configured to be movable in the pump chamber 1 along the camshaft axial direction A, and the injection cam gear 3 and the idle gear 4 are configured as a tooth meshing structure 12 Is a fuel injection timing adjustment device for a diesel engine.

[0007]

When the operation means is loaded in the rotation operation part 10 and the rotation adjusting tool 8 is rotated, the rotation adjusting tool 8 moves in the cam shaft center direction A with respect to the pump chamber 1 via the screw fitting part. As the entire fuel injection cam shaft 2 moves in the pump chamber 1 in the axial direction A, the injection cam gear 3 fixed to the cam shaft 2 also moves. The idle gear 4 has a helical structure 1
The injection cam gear 3 meshing with the 2 rotates relative to the idle gear 4 which has stopped rotating, along the torsion angle thereof. Therefore, the fuel injection cam shaft 2 can be twisted and rotated with respect to the crankshaft (that is, the crank angle) to adjust the injection timing of the fuel injection pump 5.

[0008]

(1) The injection timing of the fuel injection pump can be adjusted by simply twisting and rotating the fuel injection cam shaft simply by rotating the rotation adjuster by the operating means. Therefore,
Individual diesel engines can be quickly and easily adjusted to the injection timing that suits the application, for example, an engine set for blue-white smoke suppression can be easily re-set for NOx reduction.

(2) A rotation adjusting tool is provided on the fuel injection cam shaft,
Since the injection cam gear is an idle gear and has a simple toothed structure, it can be implemented at low cost.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional front view of a main part of a fuel injection timing adjusting device for a vertical diesel engine, in which a vertical diesel engine E is provided with a pump chamber 1 and a gear chamber 11 adjacent to each other, and a fuel injection pump 5 is provided in the pump chamber 1. And the fuel injection cam shaft 2 is laterally supported via the bearings 6 and 7 from the pump chamber 1 to the gear chamber 11, and the injection cam 2a of the fuel injection cam shaft 2 can be injected into the fuel injection pump 5. Work together. An injection cam gear 3 is fixed to the fuel injection cam shaft 2 so as to face the gear chamber 11, and a crank shaft (not shown) is interlocked with the injection cam gear 3 via an idle gear 4 so that power can be transmitted.

A male screw 15 is cut on the outer peripheral surface of the substantially circular cup-shaped rotation adjusting tool 8, and a hexagonal hole-shaped rotation operating portion 10 is recessed in an end wall 16 of the rotation adjusting tool 8 to form an outer wall 13 of the pump chamber 1. Then, the rotation adjusting tool 8 is screw-fitted in the axial direction A of the fuel injection cam shaft 2. Further, the right bearing 6 is pressed against and supported by the rotation adjusting tool 8, and the left bearing 7 is supported by the gear chamber 1 of the pump chamber 1.
It is configured to be movable along the cam shaft center direction A on the partition wall 14 with 1. The injection cam gear 3 is replaced with the idle gear 4 below.
The helical gear meshing structure 12 is configured to be engageable, and the injection cam gear 3 is meshed with the idle gear 4 while having an excessive thickness to secure a gear movement adjustment allowance 17 in the helical gear structure 12.

On the other hand, a retreat opening 19 is provided through a rib wall 18 extending in the radial direction of the fuel injection cam gear 3, and the governor weight 20 can be swung on the injection cam gear 3 in a state of being sunk into the retreat opening 19. While supporting, the governor sleeve 21 is inserted into the left end portion of the injection cam shaft 2 so as to be able to move forward and backward, and the governor sleeve 21 can be pushed out by the governor weight 20. The governor lever 22 is swingably supported in the gear chamber 11 of the diesel engine E, and
Of the governor lever 20 is connected to the injection rack 26 of the fuel injection pump 5 by a connector 27, and the input portion 23 of the governor lever 21 is interlocked with the governor sleeve 21 via the swing adjusting screw 25. Interlock a governor spring (not shown). As a result, the governor lever 22 is swung by the unbalanced force between the governor force generated by the rotation of the governor weight 20 and the spring force of the governor spring, and the rack position of the fuel injection pump 5 is adjusted to match the rotational speed of the engine E. Configure as possible.

Therefore, the adjustment procedure of the fuel injection timing adjusting device of this embodiment will be described. The hexagonal wrench 30 is engaged with the rotation operating part 10 to rotate the rotation adjusting tool 8 and the screw fitting part 15. As the rotation adjusting tool 8 moves in the cam shaft center direction A with respect to the pump chamber 1 via the screw fitting portion 15, the injection cam gear 3 fixed to the fuel injection cam shaft 2 also moves in the shaft center direction A. To do. The fuel injection cam gear 3, which meshes with the helical gear 12 in the idle gear 4, rotates relative to the idle gear 4, which is not rotating, along its torsion angle. For this reason,
The fuel injection camshaft 2 is twisted and rotated with respect to the crankshaft, and the injection cam 2a of the camshaft 2 is advanced or retarded by about 1.5 degrees in C / R angle to allow the fuel injection pump 5 to rotate. Adjust the injection timing properly.

That is, the fuel injection cam shaft 2 can be simply twisted and rotated to adjust the injection timing of the fuel injection pump 5 simply by rotating the rotation adjusting tool 8 with the operating means 30 such as a wrench. Therefore, for example, if the injection pump 5 is adjusted to the advance side, the diesel engine E can be set to suppress blue-white smoke or black smoke, and if adjusted to the retard side, the engine E can be set.
Can be easily set for NOx reduction. Further, by adjusting the swing adjusting screw 25 of the governor lever 22, the rack position of the injection pump 5 can be changed via the governor lever 22, so that the fuel injection amount of the fuel injection pump 5 can be easily adjusted.

In the present invention, the fuel injection cam shaft 2 moved left and right by the operation tool 30 is twisted with respect to the crank angle by the helical gear structure 12 between the fuel injection cam shaft 2 and the idle gear 4 to adjust the fuel injection timing. Since it is to be adjusted, the structure is not limited to the structure in which the governor shaft is also used as the fuel injection cam shaft 2 as in the above embodiment, but the structure is such that the governor is set separately from the fuel injection cam shaft 2. It doesn't matter.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view of essential parts of a fuel injection timing adjustment device for a vertical diesel engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump chamber 2 Fuel injection cam shaft 3 Injection cam gear 4 Idle gear 5 Fuel injection pump 6 One bearing 7 The other bearing 8 Rotation adjustment tool 10 Rotation operation part 12 Bevel gear meshing structure A 2 Axial direction E Diesel engine

Claims (1)

[Claims] 1. A pump chamber (1) of a diesel engine (E)
The fuel injection cam shaft (2) is supported by bearings (6) and (7), and the crankshaft is connected to the injection cam gear (3) fixed to the fuel injection cam shaft (2) via the idle gear (4). In a diesel engine in which the fuel injection cam shaft (2) is interlocked with the fuel injection pump (5) housed in the pump chamber (1) so as to be able to transmit power, the rotation operation part is provided in the pump chamber (1). The rotation adjusting tool (8) provided with (10) is screw-fitted in the axial direction (A) of the fuel injection cam shaft (2), and one bearing (6) is supported by the rotation adjusting tool (8). The other bearing (7) is configured to be movable in the pump chamber (1) along the direction of the cam shaft center (A), and has a tooth meshing structure (12) for injecting the injection cam gear (3) and the idle gear (4). A fuel injection timing adjusting device for a diesel engine, which is characterized by being configured.