JPH0450457Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is an injector in which an injector is housed in the cylinder head at an angle with respect to the axis of the piston, and the injector is opened and closed in response to the rotation of the crankshaft. related to switchgear.

[Prior Art] In general, a fifth cylinder head structure has a camshaft at the top of the cylinder head to open and close intake and exhaust valves, and a fuel injection nozzle that directly supplies atomized fuel into the combustion chamber of the piston. , and the proposal shown in Figure 6 (Utility Model Application Publication No. 1983-92802)
It has been known.

In the figure, a is a cylinder head, b is a camshaft, c and d are intake and exhaust ports, e and f are intake and exhaust valves, and g is a fuel injection nozzle.

In these conventional examples, the intake/exhaust ports c, d are located as close to the axis of the piston (not shown) as possible, and the fuel is placed close to the intake/exhaust ports c, d. In order to position the injection port n of the injection nozzle g, the rear end of the fuel injection nozzle g is tilted away from the stem ends h and i of the intake and exhaust valves e and f. . The rocker arm k that drives the opening/closing part j of the fuel injection nozzle g thereby controls the intake/exhaust valves e,
It was operated by a swing cam of a camshaft b provided on the opposite side of f.

[Problems to be solved by the invention] Although the above conventional example can operate the intake/exhaust valves and the fuel injection nozzle with a single camshaft, the rocker arm that operates the fuel injection nozzle straddles the intake/exhaust valves. Because it extends toward the fuel injection nozzle side, the rocker arm becomes larger, which necessitates making the cylinder head cover larger to match.
92802), the cylinder head had to be enlarged laterally.

However, increasing the size of the rocker arm is undesirable because it increases the unit weight, inertia weight, and friction. This has made it difficult to accommodate the engine room, which has limited space.

[Means for solving the problems] This invention aims to solve the above problems.

This design has a first rocker arm shaft used for driving the intake/exhaust valves on one side of the upper chamber of the cylinder head in the row direction of the intake/exhaust valves, and an injector opening/closing section on the other side. Second rocker arm shafts used for opening and closing are provided in parallel with each other, and the first rocker arm shaft is rotatably provided with a rocker arm for the intake valve and a rocker arm for the exhaust valve. A driving rocker arm is rotatably provided between the rocker arm and the second rocker arm shaft. The action point of the active rocker arm is articulated with a push rod that passes between the intake and exhaust valves, and a cam is provided on one side of the upper chamber to open and close the intake rocker arm, the exhaust rocker arm, and the active rocker arm, respectively. The camshaft is provided to constitute an opening/closing device for the injector.

[Operation] When the camshaft is rotationally driven, the main drive rocker arm is swung according to the lift amount of the cam that operates the main drive rocker arm. When the main rocker arm is swung, the driven rocker arm opens the opening/closing portion of the injector via the push rod.
When the lift amount of the cam that operates the driving rocker arm becomes minimum, the driven rocker arm is pushed back by the opening/closing section, and the push rod and the driving rocker arm return to their original positions. The intake valve is opened and closed by an intake valve rocker arm, and the exhaust valve is opened and closed by an exhaust valve rocker arm.

[Example] The injector opening/closing device of this invention will be explained below based on the accompanying drawings.

Reference numeral 1 shown in FIG. 1 is a cylinder head, and on the top of the cylinder head 1 is a cylinder head cover 2 that surrounds it and forms a room inside.
are integrally joined.

Inside this cylinder head 1, intake and exhaust ports 3 are opened from both sides and look into the vicinity of the combustion chamber (not shown) of a cylinder (not shown) or piston across the central axis O. , 4 are formed. These intake/exhaust ports 3, 4 are housed in the cylinder head 1 so as to be reciprocally movable, and are provided with intake/exhaust ports 3, 4 on the cylinder side, respectively.
Intake/exhaust valves 5 and 6 are provided for opening and closing valves 4, respectively. Further, a nozzle portion 7 equipped with a nozzle (not shown) for atomizing and supplying fuel is placed close to the intake/exhaust ports 3 and 4 on the cylinder side and located between the ports 3 and 4 to form a cylinder head. 1
An injector 8 is housed and fixed inside. A rear end portion 9 of this injector 8 is provided so as to be located on the other side 10 side of the cylinder head 1.

Therefore, this injector 8 faces into the combustion chamber at an angle with respect to the axial direction of the cylinder.

11 is a spring retainer provided in each of the intake and exhaust valves 5 and 6, 12 is an inner spring, and 13 is an outer spring.

In the upper chamber 15 defined by the cylinder head 1 and the cylinder head cover 2, a camshaft 16 is arranged parallel to the row direction of the intake/exhaust valves 5 and 6 on one side 18 of the cylinder head 1. A rocker armshaft (first rocker armshaft) 17 is provided in the upper chamber 15 between the intake/exhaust valves 5 and 6 and the camshaft 16 in parallel with the camshaft 16. is provided. Further, a driven rocker arm shaft (second rocker arm shaft) 19 is provided on the intake/exhaust valves 5, 6 and the other side 10 of the cylinder head 1 in parallel to the camshaft 16. Here, the camshaft 16 is connected to a crankshaft (not shown) via a gear train (not shown) or other power transmission means, and is rotatably supported by the cylinder head 1 or the cylinder head cover 2. Both ends of the rocker arm shaft 17 and the driven rocker arm shaft 19 are fixed to the cylinder head 1 or the cylinder head cover 2.

As shown in FIG. 2, the locking arm shaft 17 includes, in order along the axial direction of the locking arm shaft 17, a locking arm 20 for an intake valve;
Active rocker arm 21, exhaust valve rocker arm 2
2 is rotatably provided. On the other hand, the camshaft 16 includes an intake cam 23 and a swing cam 2 in this order along the axial direction of the camshaft 16.
4. The exhaust cam 25 is integrally provided. The shape of each of these cams 23, 24, 25 is a circular cam with a cam crest formed on a base circle.

On the other hand, a driven rocker arm 26 is rotatably provided on the driven rocker arm shaft 19.

Next, regarding the above-mentioned Rotsuka arm, see Figure 1.
This will be explained based on FIG.

The intake valve rocker arm 20 has arms 20a and 20b that extend in opposite directions in the radial direction, and one arm 20a contacts and slides on the cam surface 23a of the intake cam 23, and the other arm 20b is the stem end 5 of the intake valve 5
It comes into contact with a.

The exhaust valve rocker arm 22 has arms 22a and 22b that extend in opposite directions in the radial direction, and one arm 22a contacts and slides on the cam surface 25a of the exhaust cam 25, and the other arm 22b comes into contact with the stem end 6a of the exhaust valve 6.

The active rocker arm 21 has one arm 21a extending in the radial direction, and a roller 33 that rotates in contact with the cam surface 24a of the swing cam 24 is provided on one side 30 of the arm 21a in the rotational direction. There is. A spherical or arcuate pivot portion 34 is formed on the other side 31 in the rotational direction.

The driven rocker arm 26 has arms 26a and 26b extending in opposite directions in the radial direction, and one arm 26a is in contact with the opening/closing portion 41 of the injector 8. Also, the other arm 26
In b, the pivot portion 34 of the above-mentioned active rocker arm 21 is shown.
A pivot portion 35 having the same shape is formed.

Ends 37 and 38 of a push rod 36 connecting these are fitted into the pivot portion 34 of the driving rocker arm 21 and the pivot portion 35 of the driven rocker arm 26, respectively. Each end portion 37, 38 is rotatably fitted to each pivot portion 34, 35, and is provided so as to be prevented from moving in the axial direction relative to the rocker arm shaft 17 and the driven rocker arm shaft 19. Further, the push rod 36 is located above the rocker arm shaft 17 and the driven rocker arm shaft 19 and as close to the rocker arm shaft 17 and the driven rocker arm shaft 19 as possible.
Further, the push rod 3 is connected to the rocker arm shaft 17 and the driven rocker arm shaft 19.
The axial direction of 6 coincides with the tangential direction.

Next, the action will be explained.

As shown in FIGS. 1 and 2, when the camshaft 16 is driven by a crankshaft (not shown), the intake cam 23, the exhaust cam 25, the swing cam 2
4 are rotated as one, the intake/exhaust cams 23, 25 are rotated according to the lift amount of each intake/exhaust cam 23, 25.
The exhaust valves 5 and 6 are opened and closed.

When the swing cam 24 is rotated, the swing cam 24
Since the main rocker arm 21 is rotated in accordance with the amount of lift, the driven rocker arm 26 is rotated via the swingable push rod 36. When the driven rocker arm 26 is rotated, one arm 2
6a is the opening/closing portion 41 of the injector 8 via an adjustment screw 40 provided thereon.
is lowered toward the cylinder, thereby opening the nozzle and supplying atomized fuel into the combustion chamber.

When the swing cam 24 is rotated to the position where the lift amount is minimum, the driven rocker arm 26 is pushed back by the return spring force of the opening/closing part 41 of the injector 8, and fuel injection per rotation of the swing cam 24 is completed. do.

Next, another embodiment will be described based on FIGS. 3 and 4.

In the embodiment shown in FIGS. 3 and 4, the active rocker arm 21 is lowered so as to be positioned further toward the cylinder side with respect to the cylinder head cover 2.

In the embodiment shown in FIG. 3, the active rocker arm 21 has two arms 21a and 21b extending in opposite directions in the radial direction, one arm 21a having a rotatable roller 33, and the other arm 21 having a rotatable roller 33.
b, the pivot portion 34 is formed on the cylinder head cover 2 side with the roller 33 in contact with the cam surface 24a of the swing cam 24. On the other hand, the driven rocker arm 26 also
two arms 26a extending radially to opposite sides;
26b, and the pivot portion 3 is attached to the cylinder side portion of one arm 26a that is on the side of the intake/exhaust valves 5 and 6.
5 is formed.

An end portion of a push rod 36, which is shorter in length than the push rod 36 explained in the above embodiment, is fitted into each pivot portion 34, 35 so as to be rotatable and prevented from moving in the axial direction. There is.

The embodiment shown in FIG. 4 shows an example in which a camshaft 16 having an intake cam 23, a swing cam 24, and an exhaust cam 25 is arranged at a position as far upward as possible from the exhaust port 4 of the cylinder head 1.
Thereby, it is possible to provide a dimensional margin for the portion that supports the camshaft 16, and the degree of freedom in sealing processing can be improved.

As explained in the embodiments above, the main drive rocker arm 21 and the driven rocker arm 26 are connected by one push rod 36, and the push rod 36
Since the opening/closing part of the injector is operated by swinging the driven rocker arm 26 through the injector, the driven rocker arm 26 can be made smaller and lighter, reducing its weight and inertial mass and reducing friction. It becomes like this. Therefore, the height of the cylinder head cover 2 can be reduced, and an engine that is compact in the engine room can be provided.

[Effects of the Invention] As is clear from the above explanation, the injector opening/closing device of the present invention can exhibit the following excellent effects.

(1) Reduce the size and weight of the driven rocker arm,
The inertial mass and friction of this driven rocker arm can be reduced.

(2) Since the size of the driven rocker arm can be reduced, the height of the cylinder head cover can be lowered and made more compact.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a preferred embodiment of the injector opening/closing device of this invention, FIG. 2 is a view taken along the line - - of FIG. 1, and FIGS. 3 and 4 are other embodiments of this invention. FIGS. 5 and 6 are longitudinal sectional views showing a conventional example. In the figure, 1 is the cylinder head, 2 is the cylinder head cover, 3 is the intake port, 4 is the exhaust port, 5
is an intake valve, 6 is an exhaust valve, 7 is a nozzle part, 8 is an injector, 16 is a camshaft, 17 is a rock arm shaft (first rock arm shaft) 19
21 is a driven rocker arm shaft (second rocker arm shaft), 21 is a main drive rocker arm, 24 is a swing cam, 26 is a driven rocker arm, 36 is a push rod, and 41 is an opening/closing portion.

Claims (1)

[Scope of utility model registration request] In the upper chamber of the cylinder head, the first rocker arm shaft used to drive the intake/exhaust valves is placed on one side of the cylinder head in the row direction of the intake/exhaust valves, and the opening/closing part of the injector is opened/closed on the other side. second locking arm shafts used for the purpose of A main drive rocker arm is rotatably provided between the second
A driven rocker arm for opening and closing the opening/closing part of the injector is rotatably provided on the rocker arm shaft, and the force point of the driven rocker arm and the action point of the main drive rocker arm are connected by a push rod passing between the intake and exhaust valves. An opening/closing device for an injector, characterized in that a camshaft is articulated and provided on one side of the upper chamber with a cam for opening and closing an intake rocker arm, an exhaust rocker arm, and a main drive rocker arm, respectively.