JP2987724B2 - Fuel injection timing adjustment device for diesel engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for adjusting the fuel injection timing of a diesel engine, which can easily and quickly adjust the injection timing and can simplify the structure thereof.

[0002]

2. Description of the Related Art As shown in FIG. 1, a basic structure of a diesel engine to which the present invention is applied is such that a fuel injection camshaft 2 is supported in a pump chamber 1 of a diesel engine E via bearings 6, 7, and a fuel injection cam shaft 2 is provided. The crankshaft is interlocked with an injection cam gear 3 fixed to the injection camshaft 2 via an idle gear 4 so as to be able to transmit power, and the fuel injection camshaft 2 is interlocked with a fuel injection pump 5 housed in the pump chamber 1 so as to be able to inject fuel. Things.

[0003] Generally, in a diesel engine, the retardation / advance of the fuel injection timing greatly affects the exhaust gas components. For example, when the injection timing is too late, blue-white smoke or black smoke is likely to be generated, but the combustion time in the combustion chamber is shortened and combustion still occurs in the exhaust pipe, so the maximum combustion temperature is reduced and NOx is reduced. .

Conventionally, the fuel injection timing of a diesel engine is adjusted by changing the height of an adjuster screw of a fuel injection pump 5 or by inserting a shim between a plunger spring seat and a 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. The deviation of the injection timing becomes large. For example, in order to reset the engine set to suppress blue and white smoke to the engine for reducing NOx, a complicated operation such as changing the thickness of the shim is required. The present invention
A technical issue is to easily adjust the fuel injection timing for each individual diesel engine.

[0006]

The means for achieving the above object will be described below with reference to the drawings showing an embodiment. That is, the present invention provides forward and backward adjusted in the diesel engine of the basic structure, the rotational adjustment device 8 provided with a rotation operating part 10 on one end wall of the pump chamber 1 in the axial direction A of the fuel injection cam shaft 2
And the other bearing 6 of the fuel injection camshaft 2
Is supported by a rotation adjusting tool 8, and the other bearing 7 is
Movably supported on the other end wall along the cam axis direction A,
A fuel injection timing adjusting device for a diesel engine, wherein the injection cam gear 3 and the idle gear 4 are configured in a helical meshing structure 12.

[0007]

When the operation means is loaded into the rotation operation part 10 and the rotation adjustment tool 8 is rotated, the rotation adjustment tool 8 moves in the cam axis direction A with respect to the pump chamber 1 via the screw fitting part. As the entire fuel injection camshaft 2 moves in the pump chamber 1 in the axial direction A, the injection cam gear 3 fixed to the camshaft 2 also moves. The idle gear 4 has a helical structure 1
The injection cam gear 3 meshing with 2 rotates relative to the idle gear 4 that has stopped rotating along its torsion angle. For this reason, the fuel injection camshaft 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]

Advantages of the invention (a). The fuel injection cam shaft can be easily twisted and rotated to adjust the injection timing of the fuel injection pump simply by rotating the rotation adjuster by operating means capable of easily adjusting the fuel injection timing . Therefore, the individual diesel engine can be quickly and easily adjusted to the injection timing suitable for the application.
Easy setting for x reduction.

(B). Dedicated parts for adjusting fuel injection timing
Only one rotation adjusting tool 8 is required, the structure is simple, it is difficult to break down, and the manufacturing cost is low. The rotation adjusting tool 8 provided with the rotation operating unit 10 in the pump chamber 1 The fuel injection camshaft 2 has one bearing 6 supported by the rotation adjuster 8 and the other bearing 7 can be moved in the pump chamber 1 along the cam axis direction A by screwing in the axial direction A. Then, the injection cam gear 3 and the idle gear 4 are configured into a helical tooth meshing structure 12. From this configuration, when the rotation operation tool 30 such as a wrench is fitted to the rotation operation unit 10 and rotated, the rotation adjustment tool 8 advances and retreats along the screw fitting, and the injection cam gear is moved via the fuel injection cam shaft 2. 12 moves in the axial direction A, and the injection cam 2a of the fuel injection cam shaft 2 is advanced or retarded by an angle at which the injection cam gear 12 rotates along the helical meshing with the idle gear 4. Thus, the fuel injection timing of the fuel injection pump 5 is adjusted. Configuration required for this fuel injection timing adjustment
The following five parts are used. . Advancing and retreating the fuel injection camshaft 2 in the axial direction thereof;
Rotation adjustment tool 8. . One end of the pump chamber 1 that supports the rotation adjusting tool 8
wall. . The fuel injection camshaft 2 is slidably supported in the axial direction.
The other end wall of the pump chamber 1. . The forward / backward movement of the fuel injection cam shaft 2 in the axial direction is
Helical cam gear that converts the rotation angle of the fuel injection cam shaft 2
3. . A helical idle gear that performs the same function as this
4. Of these five components, one end wall of the pump chamber 1
Other end wall of pump chamber 1, cam gear 3, idle gear
4. The four parts are the existing parts that make up the engine.
We are using. As a result, the number of components required for adjusting the fuel injection timing is only one, that is, only the rotation adjuster 8, so that its structure is simple, it is difficult to break down, and it has excellent durability. There is an advantage that the manufacturing cost is low. (C). Eliminates an increase in the overall length of the engine for the fuel injection timing adjustment device. Only one rotation adjustment tool 8 is required for adjusting the fuel injection timing, and this rotation adjustment tool 8 is provided in the pump chamber 1. Therefore, there is no need to travel to the front side of the injection cam gear 12,
When traveling to the front side of the injection cam gear 12, it is possible to prevent the total length of the engine from being lengthened by this projecting dimension.

[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 pump chamber 1 and a gear chamber 11 are provided adjacent to a vertical diesel engine E, and a fuel injection pump 5 is provided in the pump chamber 1. And the fuel injection camshaft 2 is supported laterally via bearings 6 and 7 from the pump chamber 1 to the gear chamber 11 so that the injection cam 2 a of the fuel injection camshaft 2 can be injected into the fuel injection pump 5. Interlock. The injection cam gear 3 is fixed to the fuel injection camshaft 2 so as to face the gear chamber 11, and the crankshaft (not shown) is interlocked with the injection cam gear 3 via the idle gear 4 so as to be able to transmit power.

A male screw 15 is cut on the outer peripheral surface of the substantially circular cup-shaped rotation adjuster 8, and a hexagonal hole-shaped rotation operation section 10 is recessed on an end wall 16 of the rotation adjustment tool 8. Then, the rotation adjusting tool 8 is screwed in the axial direction A of the fuel injection camshaft 2. Further, the right bearing 6 is pressed against the rotation adjusting tool 8 to be supported, and the left bearing 7 is supported by the gear chamber 1 of the pump chamber 1.
The first partition wall 14 is configured to be movable along the cam axis direction A. The injection cam gear 3 is connected to the lower idle gear 4
The cam gear 3 is configured to be engageable with the helical gear meshing structure 12, and the injection cam gear 3 is meshed with the idle gear 4 with an extra thickness to secure a gear movement adjustment allowance 17 in the helical gear gear structure 12.

On the other hand, an evacuation opening 19 is provided through a rib wall 18 extending in the radial direction of the fuel injection cam gear 3 so that the governor weight 20 can be swung by the injection cam gear 3 in a state where the evacuation opening 19 is sunk. A governor sleeve 21 is inserted into the left end of the ejection camshaft 2 so as to be able to advance and retreat, and the governor sleeve 21 can be pushed out by the governor weight 20. A governor lever 22 is swingably supported in the gear chamber 11 of the diesel engine E.
Of the governor lever 20 is connected to the injection rack 26 of the fuel injection pump 5 by a connecting member 27, and the input portion 23 of the governor lever 20 is interlocked with the governor sleeve 21 via the swing adjustment screw 25. Operates a governor spring (not shown). As a result, the governor lever 22 is swung by the unbalance force between the governor force caused 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 engine E rotation speed. Configure as possible.

Therefore, the procedure for adjusting the fuel injection timing adjusting apparatus according to the present embodiment will be described. The hexagonal column wrench 30 is engaged with the rotation operation unit 10 to rotate the rotation adjusting tool 8 and the screw fitting unit 15. As the rotation adjuster 8 moves in the cam axis direction A via the screw fitting portion 15 with respect to the pump chamber 1, the injection cam gear 3 fixed to the fuel injection cam shaft 2 also moves in the axis direction A. I do. The fuel injection cam gear 3 meshing with the idle gear 4 by the helical structure 12 rotates relative to the idle gear 4 that has stopped rotating along the torsion angle. For this reason,
The fuel injection camshaft 2 is rotated with respect to the crankshaft, and the injection cam 2a of the camshaft 2 is advanced or retarded by, for example, about 1.5 degrees in C / R angle. Adjust the injection timing appropriately.

In other words, the fuel injection camshaft 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 by operating means 30 such as a wrench. Therefore, for example, when the injection pump 5 is adjusted to the advance side, the diesel engine E can be set for suppressing blue-white smoke or black smoke, and when the injection pump 5 is adjusted to the retard side, the engine E is adjusted.
Can be easily set for NOx reduction. Further, when the swing adjusting screw 25 of the governor lever 22 is adjusted, 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.

According to the present invention, the fuel injection camshaft 2 moved left and right by the operating tool 30 is twisted with respect to the crank angle by the helical structure 12 between the idle gear 4 and the fuel injection cam timing. Since the adjustment is performed, 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-described embodiment, and the governor is completely separated from the fuel injection cam shaft 2 and is set. No problem.

[Brief description of 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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump room 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 adjuster 10 Rotation operating part 12 Helical meshing structure A 2 Axial direction E Diesel engine

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-75825 (JP, A) JP-A-59-105039 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 1/16

Claims (1)

(57) [Claims] A pump room (1) for a diesel engine (E)
A fuel injection camshaft (2) is supported via bearings (6) and (7), and a crankshaft is connected to an injection cam gear (3) fixed to the fuel injection camshaft (2) via an idle gear (4). In a diesel engine in which a fuel injection camshaft (2) is linked to a fuel injection pump (5) housed in a pump chamber (1) so as to be able to inject fuel , the one end wall of the pump chamber (1) The rotation adjusting tool (8) having the rotation operation part (10) is moved in the axial direction (A) of the fuel injection cam shaft (2).
The bearing is fitted to the fuel injection camshaft (2) so that it can be adjusted forward and backward, and one bearing (6) of the fuel injection camshaft (2) is supported by the rotation adjusting tool (8), and the other bearing is provided.
(7) is supported on the other end wall of the pump chamber (1) so as to be movable along the cam axis direction (A), and the tooth meshing structure (12) for separating the injection cam gear (3) and the idle gear (4). A fuel injection timing adjusting device for a diesel engine, wherein the fuel injection timing adjusting device comprises: