JPS6229757A - Gas mixer for gas engine - Google Patents

Abstract

PURPOSE:To increment gas fuel smoothly upon overload by placing a power valve arranged on the throttle shaft in the gas fuel path communicating from main path of gas mixer to the mixture gas path side. CONSTITUTION:The gas fuel path 10 communicating from gas fuel main path 3 of gas mixer to the mixture gas path 20 in the downstream of throttle valve 2 is arranged at the position crossing with the throttle shaft 1. While a power valve 16 for performing open/close control of gas fuel path 10 with correspondence to the rotary angle of throttle shaft 1 rotatable together with the throttle valve 2 is provided at the crossing section of throttle shaft 1 and the path 10. Consequently, upon opening of throttle valve 2 more than predetermined level, the power valve 16 will open to increment gas fuel.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a gas mixer for a gas engine, which is equipped with a power valve for increasing the amount of gas fuel on the throttle shaft of the gas mixer to improve the output when the gas engine is overloaded. It is something.

[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 fixed to a throttle shaft 1, as shown in FIG. Power adjustment screw 4
is mixed with air A at a bench and a lily section 6 via a gas fuel passage 5 containing a If the throttle is opened more than 30 degrees, the link mechanism consisting of the lever 7, link 8, etc. connected to the throttle shaft 1 will
The power valve 9 is opened, and a larger amount of gas fuel G is supplied to the venturi section 6 through the gas fuel passage 10 provided with the power valve 9, and the increased amount of gas fuel G flows into the air mixture passage 20. Become.

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 it is difficult to adjust the lever 7, link 8, etc.
The problem is that it lacks reliability.

In addition, as in another conventional example shown in FIG. An injector 12 for fuel injection 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, the throttle sensor 13 senses this and the microcomputer Controller 1
Some gas engines have a gas mixer that sends a signal to the injector 12 and the throttle sensor 13, and in response to the signal, the microcomputer controller 11 issues a command to increase the amount of gas fuel G to the injector 12.
Moreover, the provision of the microcomputer controller 11 has the disadvantage 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 a gas engine of the present invention is a gas engine having a gas mixer with a built-in throttle valve, in which a gas fuel passage communicating from a gas fuel main passage of the gas mixer to a mixture passage side is connected to a throttle valve to which the throttle valve is fixed. In addition to placing it at a position that intersects the axis,
The gas mixer for a gas engine is 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 present invention will be described in detail 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. 2 shows a gas fuel in which the power valve of 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 FIG. 1 supplies a mixture M consisting of gas fuel G and air A to the engine side indicated by arrow E, similar to the conventional examples shown in FIGS. 4 and 5, and is different from the conventional example. Parts that are the same as those in the drawings are indicated by the same part number.

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 venturi section 6 via a gas fuel passage 5 having a gas fuel passage 14. and mixes with air A to form a mixture M.

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

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

That is, when the throttle valve 2 opens beyond a certain degree, the power valve 16 is opened by opening the throttle shaft 1, and the gas fuel G is supplied to the air mixture passage 20 via the gas fuel passage 10, and the amount of gas fuel G is increased. However, this 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 opening area of the power valve 16, which is provided to intersect with the gas fuel passage 10 for increasing the amount of gas fuel G, is the same as that of the throttle shaft 1.
As the excess air ratio changes gradually in response to the rotation of The excess air ratio can be changed from 1.0 to 1.0, and stable operating characteristics can be obtained without occurrence of rotational fluctuations such as hunting in response to the change.

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 provided. A diagram D' of excess air ratio, a diagram F' of fuel flow rate, and a diagram T' of shaft torque in the case where a conventional gas mixer is used are shown by two-dot chain lines, 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 can smoothly increase the amount of gas fuel to improve output during overload. Although the gas mixer is functional, it has the advantage of being simple in structure, requiring no adjustment, and being highly reliable.Moreover, the gas mixer can be manufactured at low cost.

Note that the present invention can be effectively applied to gas engines in general that have 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. is the first
4 and 5 are schematic cross-sectional views of main parts of different conventional gas mixers. 1... Throttle shaft, 2... Throttle valve, 3
... Gas fuel main passage, IO... Gas fuel passage,
16...Power valve, 17...Drill hole, 20...
・Mixture road.

Claims (1)

[Claims] 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 disposed at a position intersecting a throttle shaft on 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.