JPH0424140Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drive device for a unit injector.

[Prior art] Diesel engines equipped with a unit injector are disclosed in, for example, publications such as Utility Model Application No. 57-115956 and Utility Model Application No. 57-115956.
-Disclosed in Publication No. 92872. In these conventional technologies, the valve train and the drive mechanism of the unit injector are located on the same side of the cylinder head, which not only increases the width of the cylinder head, but also makes the intake port and exhaust port on the opposite side of the cylinder head. It must extend to the side. Therefore, the third
As shown in the figure, the valve train, in this case tappet 3
A camshaft 31 that drives the intake/exhaust valve 23 via the
It has been proposed that a unit injector drive mechanism is placed above the unit. That is, the roller 10 is supported at one end of the unit injector driving rocker arm 12A supported on the shaft 13 and engaged with the camshaft 31, while the abutment body 16 adjusted by the lock nut 15 is provided at the other end. , which are connected to the unit injector 18. Note that 21 is a cylinder head and 14 is a head cover. This valve mechanism is of the so-called direct attack type.

FIG. 4 shows a swing arm type. One end of the rocker arm 34 is supported by a hemispherical support member 35 fixedly supported on the cylinder head, and the other end is supported by the top end of the valve stem of the intake/exhaust valve 23. Then, the cam of the camshaft 33 is engaged with the upper abutment surface 34a of the rocker arm 34, thereby forming a valve mechanism. On the other hand, shaft 13
A roller 10 is supported at the end of the unit injector drive rocker arm 12A supported at A, and abuts against the cam of the camshaft 33, while an abutment body 16 adjusted by a lock nut 15 is supported at the other end. and is collided with the unit injector 18.

In the case shown in Figures 3 and 4, by arranging the unit injector drive rocker arm above the valve mechanism, the unit injector drive mechanism can be placed on the opposite side of the cylinder head from the valve mechanism. However, the camshafts 31, 3 of the valve mechanism
3 is placed in a relatively high part of the cylinder head, the rocker arm for driving the unit injector that is driven by this is also in a high position, and although the width of the cylinder head is narrow, the overall height is high. This poses problems such as difficulty in mounting the engine on a vehicle and the need to increase the rigidity and strength of the cylinder head as a whole.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the purpose of the invention is to provide a unit injector drive device that does not increase the width of the cylinder head and can reduce the height. be.

[Means for Solving the Problem] In order to achieve the above object, the configuration of the present invention is such that a first rocker arm is supported on a first shaft that supports a valve train rocker arm, and the first rocker arm is abutted against the first rocker arm. A second rocker arm, which has a roller at one end and an abutting body that abuts the unit injector at the other end, is supported on a second shaft parallel to the shaft and located on the opposite side of the intake/exhaust valve. This is what I did.

[Function] According to the present invention, the cam shaft or push rod for driving the valve mechanism is disposed on one side of the intake/exhaust valve 23, and the shaft 13 for supporting the rocker arm of the unit injector drive mechanism is disposed on the opposite side. be done.
The rocker arm of the valve mechanism, that is, the valve operating rocker arm 9 and the first rocker arm 7 for driving the second rocker arm 12 for driving the unit injector are supported by a common shaft 25.
The valve operating mechanism drives the valve operating rocker arm 9 and the first rocker arm 7, the first rocker arm 7 drives the second rocker arm 12, and the unit injector 18 is driven. With this mechanism, the valve train and unit injector are placed on opposite sides of the intake/exhaust valve, making it possible to reduce the overall height of the cylinder head and reduce the height of the cylinder head. It doesn't get wider either.

[Example of the invention] The invention will be explained based on an example. As shown in FIG. 1, the cylinder head 21 is connected to the intake port 2.
0 and an exhaust port 5 are provided, and an exhaust valve 23 and an intake valve (not shown) are arranged approximately in the center in the longitudinal direction of the cylinder. To explain the valve operating mechanism of the exhaust valve 23, the lower end of a push rod 4 is engaged with a camshaft 2 driven by a crankshaft 12 via a tappet 3, and this upper end is provided with a hemispherical recess. , one end 7 of the first rocker arm 7 is attached to this.
The abutting bodies 6 supported at a are abutted. This rocker arm 7 is supported by the cylinder head 21 by a shaft 25, and has an abutment surface 7b formed at the other end.

Valve operating rocker arms 9 are supported on the shaft 25 at different positions in the axial direction, and an abutment body 8 having a hemispherical protrusion supported on the end portion 9a abuts against a hemispherical recess of the push rod 4. be done. This push rod 24 is also driven by the camshaft 2 in the same way as the push rod 4. Locker arm 9 for valve train
The other end abuts the top end of the stem of the exhaust valve 23. The valve operating mechanism for the exhaust valve consisting of the push rod 24 and the valve operating rocker arm 9 is constructed in the same manner as the valve operating mechanism for the intake valve (not shown).

The second rocker arm 12 is supported on the cylinder head 21 by a shaft 13, and the roller 10 supported at one end of the second rocker arm 12 is supported on the abutment surface 7b of the first rocker arm 7.
The unit injector 18 is abutted against a unit injector 18, while an abutment body 16, which is adjustable and supported by a lock nut 15 at the other end, is abutted against the unit injector 18. A fuel supply pipe 19 is connected to the unit injector 18 from the outside, and when the unit injector 18 is reciprocated in the vertical direction, fuel is injected from the fuel injection nozzle 22 into the combustion chamber.

Next, the operation of the unit injector drive device according to the present invention will be explained. When the push rod 4 is pushed up by the cam of the camshaft 2, the rocker arm 7 is rotated clockwise about the shaft 25. As a result, the second rocker arm 12
is rotated clockwise about the shaft 13, the plunger of the unit injector 18 is pushed down, and fuel is injected from the fuel injection nozzle 22 into the combustion chamber.

In addition, in the valve mechanism, when the push rod 24 is pushed up by the cam of the camshaft 2, the valve drive rocker arm 9 is rotated clockwise about the shaft 25, and the exhaust valve 23 is pushed down against the force of the spring 17. and open the exhaust port 5.

The embodiment shown in FIG. 2 shows a type in which the valve train and unit injector drive mechanism are driven by a camshaft rather than by a push rod. A camshaft 26 driven by the crankshaft is supported on one side of the cylinder head 21 via a bearing cap 27, and one end of the valve rocker arm 9 and a roller abut against cam surfaces provided on the camshaft 26. 28 are abutted,
These rocker arms 9 and 7 are freely rotatably supported on a shaft 25 at different axial positions. The other end of the valve train rocker arm 9 is connected to an exhaust valve 23.
is abutted against the apex of the stem.

A valve operating mechanism for an intake valve (not shown) is similarly configured. An abutment surface 7b is formed at the end of the rocker arm 7. A shaft 13 is supported by a cylinder head 21 on the opposite side of the shaft 25 in the direction in which the intake and exhaust valves are arranged. A rocker arm 12 is supported on a shaft 13, and a roller 1 is supported on one end of the rocker arm 12.
0 is engaged with the abutment surface 7b, while the abutment body 1 is adjustable and supported at the other end by a lock nut 15.
6 is collided with unit 18. The operations of the valve train and unit injector drive mechanism are the same as in the example shown in FIG.

[Effects of the invention] As described above, the present invention shares the shaft 25 that supports the valve-operating rocker arm 9 of the valve mechanism, and connects the first rocker arm 7 for driving the unit injector.
is supported, and a shaft 13 is disposed on the opposite side of this shaft 25 and the intake/exhaust valve (with respect to the longitudinal direction of the cylinder head 21), and a second
One end of the rocker arm 12 is brought into contact with the abutting surface 7b via the roller 10, while the other end is brought into contact with the unit injector 18. In other words, the valve mechanism and the unit injector 1
8 are placed on the opposite side of the intake/exhaust valves, the height of the cylinder head can be suppressed and the cylinder head can be housed compactly without increasing its width.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a unit injector injector drive device according to a first embodiment of the present invention, and FIG. 2 is a front sectional view of a unit injector injector drive device according to a second embodiment of the present invention. 3 and 4 are front sectional views showing conventional unit injector injector drive devices, respectively. 2...Cam shaft, 4...Push rod, 7...
First rocker arm, 9... Valve train rocker arm, 12... Second rocker arm, 13... Second rocker arm.
shaft, 14...head cover, 18...unit injector, 21...cylinder head, 22...
...Fuel injection nozzle, 25...First shaft, 26...
cam shaft.

Claims (1)

[Scope of utility model registration request] A first shaft is attached to a first shaft that supports a rocker arm for a valve train.
a second rocker arm that supports the first rocker arm, has a roller at one end that abuts against the first rocker arm, and has an abutment body that abuts the unit injector at the other end.
A drive device for a unit injector, characterized in that a rocker arm is supported on a second shaft parallel to the shaft and located on the opposite side of the intake/exhaust valves.