JPS6136755Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention uses only gas, A
The present invention relates to a gas valve drive device for a gas engine that can use only heavy oil or a mixture of gas and A heavy oil.

Conventionally, as shown in FIG. 1, this type of gas valve driving device has conventionally operated a gas valve 44 together with an intake valve 43 by an intake valve arm 42 that engages with an intake cam 41.
A valve arm 53 operated by an intake cam 52 via a push rod 51 is interlocked with an auxiliary valve arm 55 that rotates about a shaft 54 as shown in FIG. ), and there is a structure in which the intake valve 56 and the gas valve 57 are opened and closed by the sub-valve arm 55. However, since both of the drive devices shown in FIGS. 1 and 2 use the intake cams 41 and 52 to drive the gas valves 44 and 57, the gas valves 44 and 57 are dependent on the intake timing.
The opening/closing timing of the gas valve cannot be set arbitrarily, and the opening/closing performance of the gas valve is severely restricted. Although not shown, there is also a structure in which a hydraulic pump is driven by a gas valve cam, and the gas valve is driven by the action of the hydraulic pump, but this takes up space for the arrangement of the hydraulic pump, hydraulic hoses, etc., and also increases production costs. It was expensive.

The purpose of this invention is to solve the above-mentioned problems, and its purpose is to provide a gas valve that has a simple structure and that allows the gas supply timing and period to be set to the optimum conditions that suit the engine. An object of the present invention is to provide a driving device. The present invention will be explained below based on the drawings.

In FIG. 3, which is a longitudinal cross-sectional partial view of the gas engine, 1 is a cylinder block, 2 is a cylinder head fixed to the upper end of the cylinder block 1,
The cylinder head 2 has an intake passage 3 and an exhaust passage 4.
are formed, and both passages 3 and 4 open from above into a combustion chamber 7 via an intake valve 5 and an exhaust valve 6, respectively. An intake manifold 8 is connected to the air inlet side of the intake passage 3 (the left end side in FIG. 3), and an air intake section 9 such as an air cleaner is connected to the intake manifold 8.

A cam chamber 10 is formed on the side of the cylinder block 1, and a window hole 11 is formed on the outside of the cam chamber 10 (on the left side in FIG. 3). Cam chamber 10
A camshaft 12 is disposed in the camshaft 1.
2 is rotatably supported on a side wall of the cam chamber 10 (a wall parallel to the paper plane of FIG. 3), and the cam shaft 12 is interlocked and connected to the crankshaft of the engine via a gear transmission mechanism. An intake cam 15 and an exhaust cam (not shown) are formed on the camshaft 12.
is engaged with the lower end surface of a tapepet 16 which is cylindrical with an upward opening and a bottom, and an intake push rod 1 is disposed inside the tapepet 16.
7 is inserted from above, and the lower end of the push rod 17 is in contact with the bottom wall of the tapepet 16. The upper end of the push rod 17 is operatively connected to the intake valve 5 via an intake valve arm in the cylinder head 2.

A gas valve cam 20 is formed on the camshaft 12 separately from the intake cam 15 and the exhaust cam, that is, at a portion of the camshaft 12 that is spaced apart from the intake cam 15 and the like in the axial direction. At the end of the hole 11,
A gas valve drive device 18 consisting of a valve arm 21 for a waste valve, a drive case 22, etc. is attached as one unit. That is, the drive case 22 is connected to the bolt 19.
(FIG. 4), it is detachably fixed to the end of the cam chamber 10 on the side of the window hole 11 so as to cover the window hole 11, and the inside of the drive case 22 communicates with the cam chamber 10. The center portion of the gas valve arm 21 is rotatably supported by a support shaft 23, and the support shaft 23 is connected to the drive case 22.
is fixed. One end of the gas valve arm 21 is engaged with the gas valve cam 20 via a rotating roller 25, and the other end of the gas valve arm 21 is engaged with the gas valve cam 20 via a ball joint consisting of a spherical bearing 35 and a ball 36. Rod part 2
It is pivotally connected to the lower end of 6a. Spherical bearing 35
is screwed into the gas valve valve arm 21. By adjusting the position of the spherical bearing 35 on the valve arm 21 for the waste valve in the vertical direction, the lift amount of the gas valve 26 can be adjusted. A valve case 27 that penetrates the upper wall of the drive case 22 is provided at the upper end of the drive case 22.
is fixed to the valve case 27, and the valve case 2 is fixed to the valve case 27.
A gas valve 26 that vertically penetrates through the gas valve 7 is held so as to be vertically movable. Drive case 2 of valve case 27
A valve spring 28 is disposed between the lower end surface of the rod portion 26a and the spring receiving washer 26b fixed to the lower end portion of the rod portion 26a.
is compressed, and the gas valve 26 is seated on the valve seat at the upper end of the valve case 27 due to the elastic force of the valve spring 28. An inlet branch pipe 29 is fixed to the upper end of the valve case 27, and a gas main pipe 31 is connected to this inlet branch pipe 29. That is, the gas passage 30 of the valve case 27 communicates with the main gas pipe 31 via the gas valve 26 and the passage within the branch pipe 29. A gas supply pipe 32 is connected to the outlet of the gas passage 30 in the valve case 27 as shown in FIG. 4, and an L-shaped gas supply pipe 33 fixed to the lower wall of the intake manifold 8 is connected to the gas supply pipe 32 is connected. The gas supply pipe 33 penetrates the lower wall of the intake manifold 8 and protrudes into the intake manifold 8.
The outlet faces the cylinder head 2 side.

FIG. 4 is a cross-sectional view taken from FIG. 3, and in FIG. 4, one set of gas valve drive devices 18 is installed in each cylinder as a unit.

Next, the operation of the drive device 18 will be explained.
While the roller 25 is in contact with the base circle of the gas valve cam 20, the gas valve 26 is closed. roller 25
When the rod portion 26a starts to come into contact with the cam surface of the gas valve cam 20, the rod portion 26a is pushed up via the gas valve valve arm 21, the gas valve 26 opens, and the gas sent from the main gas pipe 31 to the branch pipe 29 is released. The gas passes through the gas valve 26, the gas passage 30, the gas supply pipe 32, and the gas supply pipe 33, and is supplied into the intake manifold 8.

Note that when this engine is used only with A heavy oil as fuel, the entire gas valve drive device 18 is removed as one unit from the side wall on the window hole 11 side of the cam chamber 10 and the intake manifold 8. A cover covering the window hole 11 may be fixed to the side wall on the 11 side, and a lid may be placed on the lower end of the gas supply pipe 33.

As explained above, according to the present invention: (1) A gas valve cam 20 separate from the intake cam 15 and exhaust cam of the camshaft 12 is formed, and the gas valve valve arm 21 is controlled by the gas valve cam 20. Since the gas valve 26 is driven through the gas valve cam 2, the cost is not high, and the gas valve cam 2
0 shape and the formation position in the circumferential direction of the camshaft can be arbitrarily selected without being restricted, so it is possible to obtain the optimal gas valve opening/closing timing and gas supply period with respect to the intake timing.
Engine output can be easily improved.

(2) Since the gas valve arm 21 and rod part 26a are provided separately from the intake valve push rod 17 and the intake valve valve arm, in order to drive the gas valve 26, the push rod 17 and the intake valve valve arm are An unreasonable load is not applied, and therefore the intake valve 5 and the gas valve 26 can be driven well at all times.

(3) A cam chamber 10 is provided on the side of the cylinder block 1, a window hole 11 is formed on the side of the cam chamber 10,
A gas valve 26, a gas valve case 27, and a gas valve valve arm 21 are attached to the gas valve drive case 22 to form one unit, and the gas valve drive case 22 is detachably attached to the cam chamber window hole 11 as the unit. Since the valve arm 21 for the gas valve is fixed to the cam 20 for the gas valve, the gas valve 2
6, valve arm 21, etc. are individually attached to the cylinder block or other parts,
The installation work and inspection and repair work of the gas valve driving device 18 and the gas valve 26 are facilitated. Furthermore, the cylinder block 1 and the cylinder head of a general diesel engine can be used as they are in a gas engine without modification, thereby streamlining the production of the gas engine and making it extremely economical.

(3) Since the direction in which the gas valve 26 closes is configured to match the direction in which gas flows from the branch pipe 29 (gas supply side) to the gas passage 30 in the valve case 27, when the gas valve 26 is seated, Since the pressure of the gas in the branch pipe 29 acts in the direction of increasing the seating pressure of the gas valve 26, the gas valve 26 can be reliably closed, and gas leaks into the gas passage 30 when the gas valve 26 is closed. No more worries.
That is, the opening/closing performance of the gas valve 26 is stabilized.

(5) The gas valve 26 is provided as a unit in the drive case 22 that is attached to the window hole 11 of the cam chamber 10, and the cam valve 26 and the cam 20 are connected through the window hole 11, so that the gas valve 26 and the cam are connected to each other through the window hole 11. 20 becomes shorter, and the cam valve 26 and the cam 20
Valve arm 2 for gas valve as a connecting drive device between
You can adopt a simple one with only 1. Therefore, there is no need to use a large and heavy drive device such as a conventional push rod, and the drive device 18
It is possible to achieve lighter weight and smaller size.

In addition, the force for driving the gas valve 26 can be small, and the seating load of the gas valve 26 on the valve seat and the gas valve valve arm 2 on the cam 20 can be reduced.
The pressure contact load of 1 also becomes smaller, and as a result, gas valve 2
6. Friction between the gas valve seat, the gas valve arm 21, and the gas valve cam 20 can be reduced, and durability can be improved.

[Brief explanation of the drawing]

1 and 2 are schematic vertical cross-sectional views showing a conventional gas valve drive device, FIG. 3 is a partial vertical cross-sectional view of a gas engine equipped with a gas valve drive device according to the present invention, and FIG.
FIG. 10...cam room, 12
...Camshaft, 20...Gas valve cam, 21...Gas valve valve arm, 26...Gas valve.

Claims (1)

[Scope of utility model registration request] A cam chamber is provided on the side of the cylinder block, an intake camshaft with intake and exhaust cams is arranged in the cam chamber, and a gas valve cam is formed on the camshaft separately from the intake and exhaust cams. A window hole is formed in the side part, and a gas valve, a gas valve case, and a valve arm for the gas valve are attached to the gas valve drive case to form one unit, and the gas valve drive case is attached to the cam chamber as the unit. At the same time, the valve arm for the gas valve is engaged with the cam for the gas valve, and the gas valve is driven via the valve arm for the gas valve, and the direction in which the gas valve closes is set to the gas supply side. A gas valve drive device for a gas engine, characterized in that a gas valve is arranged in a gas valve case so as to match the flow of gas from the gas valve to the gas valve case.