JPH0379544B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a gas mixer for a gas engine, which improves the output when the gas engine is overloaded by providing a power valve for increasing the amount of gas fuel on the throttle shaft of the gas mixer. It is related to.

[Prior art]

When forming a mixture of gas fuel and air in a gas engine that uses gas fuel, in order to achieve high thermal efficiency and low exhaust emissions during normal operation of the engine, it is necessary to form a lean mixture and to When overloaded, it is necessary to increase the amount of gas fuel to improve output.

Therefore, the conventional gas mixer used for this purpose has a built-in throttle valve 2 fixedly attached to the throttle shaft 1, as shown in FIG. ,
The air mixture M is mixed with air A at the bench lily section 6 via a gas fuel passage 5 containing a built-in power adjuster screw 4, and is supplied to the engine side as shown by arrow E. valve 2
When the opening exceeds a certain degree, the power valve 9 is opened via a link mechanism consisting of a lever 7, a link 8, etc. connected to the throttle shaft 1, and the gas fuel passes through the gas fuel passage 10 in which the power valve 9 is installed. A larger amount of gas fuel G is supplied to the bench lily portion 6, and the increased amount of gas fuel G flows into the mixture passage 20.

However, in the conventional example shown in FIG. 4, the structure in which the amount of gas fuel G is increased through the link mechanism is complicated, and the lever 7 and the link 8 are difficult to adjust, resulting in a lack of reliability. There is.

In addition, as in another conventional example shown in FIG. 5, in addition to the gas fuel passage 5 that supplies the gas fuel G to the bench lily part 6, the gas fuel G is supplied to the mixture passage 20 downstream of the bench lily part 6 when increasing the amount of fuel. A fuel injection injector 12 controlled by a microcomputer controller 11 is interposed in the gas fuel passage 10 that can be supplied, and when the throttle valve 2 opens more than a certain degree, a throttle sensor 13 detects this. , microcomputer controller 1
Some gas engines have a gas mixer that sends a signal to the injector 1, and the signal causes the microcomputer controller 11 to issue a command to increase the amount of gas fuel G to the injector 12.
2. Throttle sensor 13 and microcomputer controller 1
1, the disadvantage is that the cost increases.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned conventional problems, and provides a gas mixer that can increase the amount of gas fuel in order to improve the output of a gas engine when it is overloaded, with a simple structure and at a low cost. The purpose of this invention is to provide a highly reliable gas mixer.

[Structure of the invention]

That is, the gas mixer for the gas engine of the present invention is
In a gas engine having a gas mixer with a built-in throttle valve, a gas fuel passage communicating from a gas fuel main passage of the gas mixer to a mixture passage side is arranged at a position intersecting a throttle shaft on which the throttle valve is fixedly installed. The present invention also comprises a gas mixer for a gas engine, characterized in that a power valve for controlling opening and closing of the gas fuel passage in accordance with the rotation angle of the throttle shaft is provided at a portion of the throttle shaft that intersects with the gas fuel passage.

〔Example〕

The details of the present invention will be explained below with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a gas mixer according to an embodiment of the present invention, and FIG. FIG. 2 is an enlarged cross-sectional view of the main part of the passage in the direction of arrow H.

First, the gas mixer shown in Figure 1 is similar to the one shown in Figures 4 and 5.
Similar to the conventional example shown in the figure, a mixture M consisting of gas fuel G and air A is supplied to the engine side indicated by arrow E, and the same parts as in the drawing of the conventional example are indicated by the same part numbers.

That is, this gas mixer has a built-in throttle valve 2 fixed to a throttle shaft 1, and supplies gas fuel G supplied from a gas fuel main passage 3 to a bench lily portion 6 via a gas fuel passage 5 having a jet 14. and mixes with air A to form a mixture M.

Therefore, the gas mixer of the present invention has a gas fuel passage 10 that opens and communicates from the gas fuel main passage 3 to the mixture passage 20 on the downstream side of the throttle valve 2.
is arranged at a position intersecting the throttle shaft 1, and a gas fuel passage 10 is provided at the intersection of the throttle shaft 1 and the gas fuel passage 10 in accordance with the rotation angle of the throttle shaft 1 that rotates together with the throttle valve 2.
A power valve 16 is provided to control opening and closing.

As shown in FIG. 2, the power valve 16 in this embodiment has a perforated hole 17 in the main body of the throttle shaft 1 with a cross section that is almost the same as that of the gas fuel passage 10, and its structure is very simple. As the throttle shaft 1 rotates in the direction of the arrow R, the perforated hole 17 rotates when the power valve 16 is fully closed, as shown by the broken line of the arrow X in FIG. 2 when the throttle valve 2 is fully closed. From the state, the power valve 16 starts operating as shown by the broken line of the arrow Y, and then goes to the state of the arrow Z when the throttle valve 2 is fully open.
Until the power valve 16 is fully open as shown by the solid line,
The opening degree of the gas fuel passage 10 can be controlled to open or close.

That is, when the throttle valve 2 opens beyond a certain degree, the throttle shaft 1 opens, the power valve 16 opens, and the gas fuel G flows into the gas fuel passage 10.
The amount of gas fuel G is increased by being supplied to the air-fuel mixture passage 20, and the power valve 16 is provided on the throttle shaft 1 and has a very simple structure and can be formed at low cost.

The power valve 16 in the above embodiment has a spool valve structure, but the power valve 16 is not limited to the embodiment shown in FIG. You may also use a structure like this.

Further, the opening degree at which the power valve 16 starts operating can be changed as appropriate by simply changing the diameter of the perforated hole 17, and no adjustment is necessary.

If the gas mixer of the present invention having the above configuration is used, the gas fuel passage 10 for increasing the amount of gas fuel G can be used.
Since the opening area of the power valve 16, which is installed across the throttle axis, changes gradually in response to the rotation of the throttle shaft 1, the throttle opening changes as shown in the excess air ratio diagram D in Figure 3. From fully closed to fully open, it is possible to change from a fairly lean state with an aeration multiplier of 1.4 to an excess air ratio of 1.0, and stable operating characteristics are maintained with no rotation fluctuations such as hunting due to the change. can get.

In addition, in FIG. 3, the graph F of the fuel flow rate with respect to the throttle opening of the gas mixer of this embodiment and the graph T of the engine shaft torque are shown as solid lines, and the power valve 16 is not provided. Diagram of excess air ratio when using a conventional gas mixer
D′, fuel flow diagram F′, and shaft torque diagram
T' is shown by a two-dot chain line, respectively.

〔Effect of the invention〕

Therefore, the gas mixer of the present invention can form a lean mixture to achieve high thermal efficiency and low exhaust emissions during normal operation, and
The gas mixer has the ability to smoothly increase the amount of gas fuel to improve output in the event of an overload, and has the advantage of being simple in structure, requiring no adjustment, and being highly reliable. It has the advantage of being manufacturable.

Note that the present invention can be effectively applied to all gas engines having a throttle valve.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a gas mixer according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part of a gas fuel passage in the direction of arrow H in which the power valve of FIG. shows diagrams of excess air ratio, fuel flow rate, and shaft torque corresponding to the throttle opening of the gas mixer shown in Fig. 1, and Figs. 4 and 5 are schematic cross-sectional views of main parts of different conventional gas mixers. It is. 1...Throttle shaft, 2...Throttle valve, 3...Gas fuel main passage, 10...Gas fuel passage, 16...Power valve, 17...Drill hole, 20...Mixture mixture passage.

Claims (1)

[Claims] 1. In a gas engine having a gas mixer with a built-in throttle valve, a gas fuel passage communicating from the gas fuel main passage of the gas mixer to the mixture passage side is arranged at a position intersecting the throttle axis to which the throttle valve is fixedly installed, and A gas mixer for a gas engine, characterized in that a power valve for controlling opening and closing of the gas fuel passage in accordance with the rotation angle of the throttle shaft is provided at a portion of the throttle shaft that intersects with the gas fuel passage.