Gas fuel supply device and engine generator

Abstract

The present invention is provided with a gas fuel regulator (32) that sets the flow rate of a gas fuel to a prescribed value, and a spacer (50) that is provided between an air cleaner that sends air to an engine and a carburetor for liquid fuel. The gas fuel regulator (32) comprises: a gas fuel pressure regulating chamber (32c) surrounded by an inner surface of a regulator housing (32a) and a diaphragm (60) that comprises a disc-shaped protrusion part (60d) with a triangular ridge-shaped cross section extending in the circumferential direction; and a valve body (40) for controlling the flow rate of the gas fuel supplied to the gas fuel pressure regulating chamber (32c) in conjunction with movement of the diaphragm (60) around the axis thereof. The spacer (50) comprises a hollow passage (50d) having a thick-plate shape and penetrating in a direction perpendicular to the plane of the spacer (50), and a communication passage (50c) bored in the spacer (50) for communicating the hollow passage (50d) and the gas fuel pressure regulating chamber (32c) of the gas fuel regulator (32).

Description

Gaseous fuel supply device and engine generator

[0001] The present invention relates to a gaseous fuel supply device for driving a liquid fuel-driven engine with gaseous fuel, and an engine generator having the gaseous fuel supply device.

[0002] Conventionally, gaseous fuel supply devices have been proposed for driving a liquid-fuel-driven engine with gaseous fuel, particularly gaseous fuel supply devices that can accommodate different types of gaseous fuel (e.g., propane gas, city gas, etc., which have different energy contents).

[0003] For example, in the engine fuel supply device of Patent Document 1, a hollow spacer is provided in an air supply passage that leads intake air from an air cleaner to a carburetor, and the hollow spacer is connected to the air supply passage. An inlet passage that leads fuel gas from the outside is provided with a regulator that sets the fuel gas pressure to a predetermined level. The spacer leads the fuel gas that has passed through the regulator and forms a connecting passage that opens into the hollow spacer. The connecting passage has multiple openings, and the spacer is provided with a switching valve for selecting the connecting passage to lead the fuel gas depending on the type of fuel gas.

[0004] Furthermore, the engine generator in Patent Document 2 introduces liquid fuel from a fuel tank and air supply from an air cleaner into a carburetor, supplies the mixed air from the carburetor to the engine to drive the engine, and generates electricity in a generator section using the driving force.The engine generator is shown to have an intake passage for introducing fuel gas from an external supply source in an intake passage that introduces air supply from the air cleaner to the carburetor, a regulator that sets the fuel gas pressure to a predetermined value, and a gas solenoid valve at the inlet side of the intake passage that allows or restricts the introduction of fuel gas from the external supply source.

[0005] Patent Document 3 also discloses the same content as Patent Documents 1 and 2.

[0006] JP 2014-125999 A JP 2014-159777 A JP 2014-156836 A

[0007] However, conventional gaseous fuel supply devices and engine generators have structures that accommodate different types of gaseous fuel, and also use solenoid valves, which make the structures complex and make it difficult to keep costs down.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a gaseous fuel supply device and an engine generator that are simple in structure, inexpensive, and capable of running an engine with different types of gaseous fuel.

[0009] The gaseous fuel supply device according to claim 1 comprises a gaseous fuel regulator that sets a predetermined flow rate of gaseous fuel, and a spacer that is provided between an air cleaner that sends air to an engine and a carburetor for liquid fuel, wherein the gaseous fuel regulator has a gaseous fuel pressure adjustment chamber surrounded by the inner surface of a regulator housing and a disk-shaped diaphragm having a protrusion that extends circumferentially and has a triangular cross section, and a valve body that controls the flow rate of gaseous fuel supplied to the gaseous fuel pressure adjustment chamber in conjunction with movement of the diaphragm in the circumferential axis direction, the spacer is shaped like a thick plate and has a hollow passage that penetrates in a direction perpendicular to the surface of the spacer, and a communication passage that is drilled in the spacer and communicates the gaseous fuel pressure adjustment chamber of the gaseous fuel regulator with the hollow passage, and the gaseous fuel, the flow rate of which is controlled by the diaphragm, is sprayed from the hollow passage in the spacer toward the carburetor.

[0010] A gaseous fuel supply device according to a second aspect of the present invention is characterized in that, in addition to the configuration of the first aspect, the protrusion of the diaphragm protrudes toward the gaseous fuel pressure adjusting chamber.

[0011] The gaseous fuel supply device according to claim 3 is characterized in that, in addition to the configuration of claim 2, it has a disk-shaped plate that is in close contact with the diaphragm and is located closer to the center of the circle than the protrusion on the surface of the diaphragm facing the gaseous fuel pressure adjusting chamber.

[0012] A gaseous fuel supply device according to a fourth aspect of the present invention is characterized in that, in addition to the configuration of any one of the first to third aspects, the diaphragm is made of an elastic material and a reinforcing base fabric material.

[0013] In the engine generator of claim 5, the gaseous fuel supply device comprises a gaseous fuel regulator that sets a predetermined flow rate of gaseous fuel, and a spacer provided between an air cleaner that sends air to the engine and a carburetor for liquid fuel, the gaseous fuel regulator having a gaseous fuel pressure adjustment chamber surrounded by the inner surface of a regulator housing and a disk-shaped diaphragm having a protrusion that extends circumferentially and has a triangular cross section, and a valve body that controls the flow rate of gaseous fuel supplied to the gaseous fuel pressure adjustment chamber in conjunction with movement of the diaphragm in the circumferential axis direction, the spacer having a thick plate-like hollow passage that penetrates in a direction perpendicular to the surface of the spacer, and a communication passage drilled in the spacer that communicates the gaseous fuel pressure adjustment chamber of the gaseous fuel regulator with the hollow passage, and the gaseous fuel whose flow rate is controlled by the diaphragm is sprayed from the hollow passage in the spacer toward the carburetor.

[0014] According to a sixth aspect of the present invention, in addition to the configuration of the fifth aspect, the engine generator is characterized in that the protrusion of the diaphragm protrudes toward the gaseous fuel pressure adjusting chamber.

[0015] The engine generator according to claim 7 has the same features as claim 6, and further has a disk-shaped plate that is in close contact with the diaphragm and is located closer to the center of the circle than the protrusion on the surface of the diaphragm facing the gas fuel pressure adjusting chamber.

[0016] The engine generator according to claim 8 has the configuration of any one of claims 5 to 7, and is characterized in that the diaphragm is made of an elastic material and a reinforcing base fabric material.

[0017] The gaseous fuel supply device and engine generator of the present invention have a simple structure, are inexpensive, and can run the engine on different types of gaseous fuel.

[0018] FIG. 1 is an explanatory diagram showing an overview of an engine generator according to the present invention. FIG. 2 is an explanatory diagram showing details of the engine generator. FIG. 3 is an explanatory diagram showing the appearance of a gaseous fuel supply device according to the present invention. FIG. 4 is an explanatory diagram showing the appearance of the gaseous fuel supply device. FIG. 5 is an explanatory diagram showing a plan view of the gaseous fuel supply device. FIG. 6 is an explanatory diagram showing a gaseous fuel pressure regulating chamber of the gaseous fuel supply device. FIG. 7 is an explanatory diagram showing a cross section of a gaseous fuel regulator and a spacer of the gaseous fuel supply device. FIG. 8 is an explanatory diagram showing a cross section of a gaseous fuel regulator and a gaseous fuel supply unit of the gaseous fuel supply device. FIG. 9 is an explanatory diagram showing a plan view of a diaphragm of the gaseous fuel supply device. FIG. 10 is an explanatory diagram showing a cross section of a diaphragm of the gaseous fuel supply device. FIG. 11 is an explanatory diagram showing the operation of the gaseous fuel supply device. FIG. 12 is an explanatory diagram showing the operation of the gaseous fuel supply device.

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an overview of an engine generator according to the present invention. FIG. 2 is an explanatory diagram showing details of the engine generator. FIG. 3 is an explanatory diagram showing the appearance of a gaseous fuel supply device according to the present invention. FIG. 4 is an explanatory diagram showing the appearance of the gaseous fuel supply device. FIG. 5 is an explanatory diagram showing a plan view of the gaseous fuel supply device. FIG. 6 is an explanatory diagram showing a gaseous fuel pressure adjustment chamber of the gaseous fuel supply device. FIG. 7 is an explanatory diagram showing a cross section of a gaseous fuel regulator and a spacer of the gaseous fuel supply device. FIG. 8 is an explanatory diagram showing a cross section of a gaseous fuel regulator and a gaseous fuel supply unit of the gaseous fuel supply device. FIG. 9 is an explanatory diagram showing a plan view of a diaphragm of the gaseous fuel supply device. FIG. 10 is an explanatory diagram showing a cross section of a diaphragm of the gaseous fuel supply device. FIGS. 11 to 13 are explanatory diagrams showing the operation of the gaseous fuel supply device.

[0020] The engine generator 1 of the present invention is a generator that has a gas fuel supply device 30 for driving a liquid-fuel-driven engine 20 with gas fuel, and generates electricity using the engine 20. As shown in FIG. 1 , the engine generator 1 has the engine 20 and other components housed inside a rectangular, case-shaped generator outer casing 10. Wheels 12 are provided at the four corners of the bottom of the generator outer casing 10. In addition, the generator outer casing 10 has two handles 14 on the top, each having a bar extending parallel to the rotation axis of the wheels 12. The engine generator 1 can be moved by pulling the handles 14 while the wheels 12 are in contact with the ground.

[0021] In addition to the engine 20, the generator outer casing 10 of the engine generator 1 is equipped with a liquid fuel tank (not shown), a liquid fuel supply port 22 for supplying liquid fuel to the liquid fuel tank, a liquid fuel valve (not shown) for turning on and off the supply of liquid fuel to the engine 20, an air cleaner 24 for sending air to the engine 20, a carburetor 26, and a generator (not shown) for generating electricity by the rotation of the engine 20. As described above, the engine generator 1 is basically configured to drive the engine 20 with liquid fuel.

[0022] However, the engine generator 1 of the present invention has a gaseous fuel supply device 30 for driving the engine 20, which is driven by liquid fuel, with gaseous fuel. The engine generator 1 is configured so that the engine 20 can be driven with gaseous fuel instead of liquid fuel to generate electricity. The gaseous fuel supply device 30 of the present application is intended to use various gaseous fuels such as propane gas and city gas as the gaseous fuel.

[0023] The gaseous fuel supply device 30 of the present invention includes a gaseous fuel regulator 32 that sets a predetermined flow rate of gaseous fuel, and a spacer 50 that is provided between the air cleaner 24 that supplies air to the engine 20 and the carburetor 26 for liquid fuel. The gaseous fuel regulator 32 is short and generally cylindrical. The spacer 50 is thick and plate-like. In the gaseous fuel supply device 30 of the embodiment, as shown in Figures 3 and 4, the spacer 50 stands with its surfaces (air cleaner-side surface 50a and carburetor-side surface 50b) facing horizontally, and the gaseous fuel regulator 32 is positioned horizontally above the spacer 50 to form an integrated unit.

[0024] However, the horizontal and vertical directions shown in Figures 3 and 4 are only illustrative of the positional relationship between the spacer 50 and the gas fuel regulator 32, and depending on how they are attached to the engine generator 1, they do not necessarily have a horizontal and vertical relationship with respect to the engine generator 1.

[0025] The gaseous fuel regulator 32 basically includes a hollow, generally disk-shaped regulator housing 32a covered by a cover 32b. As shown in FIG. 7, a disk-shaped diaphragm 60 is provided inside the regulator housing 32a to divide the regulator housing 32a. The area surrounded by the inner surface of the regulator housing 32a and the diaphragm 60 forms a sealed gaseous fuel pressure adjusting chamber 32c. A vent hole 32ba is formed in the cover 32b, allowing air to freely flow in and out of the cavity defined by the cover 32b and the diaphragm 60, maintaining atmospheric pressure.

[0026] 9 and 10, the diaphragm 60 is thin and disk-shaped and made of an elastic material. The diaphragm 60 is fixed by sandwiching the fixing pieces 60c protruding from the periphery and the outer periphery between the regulator housing 32a and the cover 32b. A protrusion 60d having a triangular mountain-like cross section and extending circumferentially is formed between the center and the outer periphery of the diaphragm 60.

[0027] As shown in FIG. 7 and other figures, the diaphragm 60 of this embodiment is disposed so that the protrusion 60d protrudes toward the gaseous fuel pressure adjusting chamber 32c.

[0028] Furthermore, although not essential, the diaphragm 60 of this embodiment has a disk-shaped plate 62 that is in close contact with the diaphragm 60 and is located closer to the center of the circle than the protrusion 60d on the surface 60a facing the gas fuel pressure adjustment chamber, for the purpose of reinforcing the diaphragm 60.

[0029] Furthermore, the diaphragm 60 of the present embodiment is made up of, for example, an elastic material and a reinforcing base fabric material.

[0030] The gaseous fuel regulator 32 includes a gaseous fuel supply unit 34, which is a system on the gaseous fuel pressure adjustment chamber 32c side to which gaseous fuel is supplied, and a system through which gaseous fuel is released from the gaseous fuel pressure adjustment chamber 32c. As shown in FIG. 8 , the gaseous fuel supply unit 34 is cylindrical and has a gaseous fuel supply passage 34b through which the gaseous fuel flows. The inlet of the gaseous fuel supply passage 34b is a gaseous fuel supply port 34a, and the outlet (gas fuel port 38) communicates with the gaseous fuel pressure adjustment chamber 32c via a valve body 40. A gaseous fuel supply tube 36 ( FIG. 2 ) is fitted to the gaseous fuel supply port 34a side of the gaseous fuel supply unit 34, through which the gaseous fuel is supplied. The valve body 40 controls the flow rate of gaseous fuel supplied to the gaseous fuel pressure adjustment chamber 32c in conjunction with the movement of the diaphragm 60 in the circumferential direction (out-of-plane direction).

[0031] The valve element 40 is opened and closed by a valve element drive blade 42. The valve element drive blade 42 is a flat plate curved into a generally L-shape. One end of the valve element drive blade 42, a valve-side end 42a, is fixed to the valve element 40, and the side closest to the valve-side end 42a forms a pivot shaft 42b that is wrapped around a pivot shaft 44 and pivotably fixed thereto. The other end of the valve element drive blade 42 forms a diaphragm abutment 42d, and a spring abutment 42c that abuts against the pivot shaft 42b while being biased by a spring 46 is located near the pivot shaft 42b. The diaphragm abutment 42d of the valve element drive blade 42 is biased by the spring 46 so that it always abuts against the diaphragm 60 in a pivotable state. In this embodiment, a pin 64 is provided in the center of the plate 62 of the diaphragm 60. The diaphragm contact portion 42d of the valve element drive blade 42 is in constant contact with the contact surface 64a of the pin 64.

[0032] As shown in Figure 7, the spacer 50 is provided with a hollow passage 50d that penetrates perpendicularly to the surfaces of the spacer 50 (the substantially parallel air cleaner-side surface 50a and carburetor-side surface 50b). The spacer 50 also has a communication passage 50c that connects the gaseous fuel pressure adjusting chamber 32c of the gaseous fuel regulator 32 with the hollow passage 50d. A cylindrical ejection cylinder 52 is inserted into the outlet of the communication passage 50c on the hollow passage 50d side, projecting into the hollow passage 50d. An ejection port 52a of the ejection cylinder 52 opens toward the carburetor-side surface 50b.

[0033] As shown in FIG. 2, the gas fuel supply device 30 is provided so that a spacer 50 is positioned between the air cleaner 24 and the carburetor 26 for liquid fuel.

[0034] In this embodiment, the gas fuel regulator 32 and the spacer 50 are integrally formed (cast), but they may be manufactured separately and then connected and fixed.

[0035] Next, the operation of the gaseous fuel supply device 30 configured as described above will be described. Note that the case where only gaseous fuel is supplied without supplying liquid fuel (a state where gaseous fuel is supplied to the gaseous fuel supply unit 34) will be described. First, when the engine 20 is stopped, as shown in FIG. 8 , the diaphragm 60 maintains its original shape, and the valve body 40 closes the gaseous fuel port 38, so that gaseous fuel is not supplied to the engine 20.

[0036] Next, when the recoil starter handle (not shown) is pulled to start the engine 20, the engine 20 begins to seek fuel, creating a negative pressure in the space from the spacer 50 to the gaseous fuel pressure adjustment chamber 32c. As a result, the diaphragm 60 deforms in a direction that narrows the gaseous fuel pressure adjustment chamber 32c (toward the surface 60a facing the gaseous fuel pressure adjustment chamber), as shown in FIG. 12 . This causes the diaphragm 60 to push the diaphragm abutment portion 42d of the valve element drive blade 42, causing the valve element drive blade 42 to swing, and the valve element 40 to open the gaseous fuel port 38.

[0037] When the gaseous fuel port 38 opens, the gaseous fuel passes through the gaseous fuel pressure adjusting chamber 32c, passes through the communication passage 50c of the spacer 50, and is ejected from the ejection port 52a of the ejection cylinder 52 toward the carburetor 26. As a result, the gaseous fuel is supplied to the engine 20, causing the engine 20 to start operating and begin generating electricity.

[0038] If the engine 20 side no longer requires a large amount of gaseous fuel while maintaining rotation, the negative pressure state in the gaseous fuel pressure adjustment chamber 32c is alleviated, causing the diaphragm 60 to return toward the back surface 60b opposite the gaseous fuel pressure adjustment chamber 32c, moving the valve body 40 and narrowing or closing the opening of the gaseous fuel port 38.

[0039] Conversely, when the engine 20 requires more gaseous fuel to make up for the lack of energy in the gaseous fuel, the degree of negative pressure in the gaseous fuel pressure regulating chamber 32c increases. As shown in FIG. 13, the diaphragm 60 deforms in a direction that further narrows the gaseous fuel pressure regulating chamber 32c, greatly moving the valve element 40. This causes the gaseous fuel port 38 to open widely, allowing a large amount of gaseous fuel to be supplied toward the carburetor 26.

[0040] That is, the gaseous fuel, the flow rate of which is controlled by the diaphragm 60 as required by the engine 20, is ejected from the hollow passage 50d of the spacer 50 in the direction of the carburetor 26.

[0041] With the gaseous fuel supply device 30 configured as described above, the amount of gaseous fuel required by the engine 20 varies depending on the type of gaseous fuel, but the diaphragm 60 has a circumferentially extending triangular-mountain-shaped protrusion 60d, which responds sensitively to changes in the pressure in the gaseous fuel pressure adjustment chamber 32c, making it possible to quickly adjust the amount of gaseous fuel. Therefore, even if gaseous fuels with different energy contents, such as propane gas and city gas, are used, the engine 20 can be operated using the same system of one type of gaseous fuel supply device 30, which simplifies the structure and reduces the cost of the device itself.

[0042] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0043] This application is based on Japanese Patent Application No. 2024-042018, filed on March 18, 2024. The entire specification, claims, and drawings of Japanese Patent Application No. 2024-042018 are incorporated herein by reference.

[0044] As described above, according to the present invention, it is possible to provide a gaseous fuel supply device and an engine generator that have a simple structure, are inexpensive, and can run an engine using different types of gaseous fuel.

[0045] DESCRIPTION OF SYMBOLS 1 Engine generator 10 Generator outer casing 12 Wheels 14 Handle portion 20 Engine 22 Liquid fuel supply port 24 Air cleaner 26 Carburetor 30 Gaseous fuel supply device 32 Gaseous fuel regulator 32a Regulator housing 32b Cover 32ba Ventilation hole 32c Gaseous fuel pressure adjustment chamber 34 Gaseous fuel supply portion 34a Gaseous fuel supply port 34b Gaseous fuel supply path 36 Gaseous fuel supply tube 38 Gaseous fuel port 40 Valve body 42 Valve body drive blade 42a Valve side end portion 42b Rotating shaft portion 42c Spring contact portion 42d Diaphragm contact portion 44.... Rotating shaft 46... Spring 50... Spacer 50a... Air cleaner side surface 50b... Carburetor side surface 50c... Communication passage 50d... Hollow passage 52... Injection cylinder body 52a... Injection port 60... Diaphragm 60a... Gas fuel pressure adjusting chamber side surface 60b... Back surface 60c... Fixing piece 60d... Projection 62... Plate 64... Pin 64a... Contact surface

Claims

1. A gaseous fuel supply device for powering a liquid-fuel-driven engine with gaseous fuel, comprising: a gaseous fuel regulator that sets the flow rate of the gaseous fuel to a predetermined level; and a spacer that is provided between an air cleaner that supplies air to the engine and a liquid-fuel carburetor; the gaseous fuel regulator has a gaseous fuel pressure adjustment chamber surrounded by the inner surface of a regulator housing and a disk-shaped diaphragm having a protrusion that extends circumferentially and has a triangular cross-section; and a valve body that controls the flow rate of the gaseous fuel supplied to the gaseous fuel pressure adjustment chamber in conjunction with the movement of the diaphragm in the circumferential direction; the spacer is thick and has a hollow passage that penetrates in a direction perpendicular to the surface of the spacer; and a communication passage that is drilled in the spacer and that connects the gaseous fuel pressure adjustment chamber of the gaseous fuel regulator to the hollow passage; The gaseous fuel supply device is characterized in that the gaseous fuel, the flow rate of which is controlled by the diaphragm, is ejected from the hollow passage of the spacer toward the carburetor.

2. A gaseous fuel supply device according to claim 1, wherein the protrusion of the diaphragm protrudes toward the gaseous fuel pressure adjusting chamber.

3. A gaseous fuel supply device according to claim 2, further comprising a disk-shaped plate in close contact with the diaphragm, the disk-shaped plate being located closer to the center of the circle than the protrusion on the surface of the diaphragm facing the gaseous fuel pressure adjusting chamber.

4. A gaseous fuel supply device according to any one of claims 1 to 3, characterized in that the diaphragm is made of an elastic material and a reinforcing base fabric material.

5. An engine generator having a gaseous fuel supply device for driving a liquid fuel-driven engine with gaseous fuel, and generating electricity using the engine, wherein the gaseous fuel supply device comprises: a gaseous fuel regulator for setting the flow rate of the gaseous fuel to a predetermined level; and a spacer provided between an air cleaner for sending air to the engine and a liquid fuel carburetor; the gaseous fuel regulator comprises: a gaseous fuel pressure adjustment chamber surrounded by the inner surface of a regulator housing and a disc-shaped diaphragm having a protrusion extending circumferentially and having a triangular mountain-shaped cross section; and a valve body for controlling the flow rate of the gaseous fuel supplied to the gaseous fuel pressure adjustment chamber in conjunction with the movement of the diaphragm in the circumferential axis direction; the spacer is thick and has a hollow passage penetrating in a direction perpendicular to the surface of the spacer; and a communication passage drilled in the spacer for communicating the gaseous fuel pressure adjustment chamber of the gaseous fuel regulator with the hollow passage; The gaseous fuel, the flow rate of which is controlled by the diaphragm, is ejected from the hollow passage of the spacer toward the carburetor.

6. The engine generator according to claim 5, wherein the protrusion of the diaphragm protrudes toward the gaseous fuel pressure adjusting chamber.

7. An engine generator according to claim 6, further comprising a disk-shaped plate in close contact with said diaphragm, on the surface of said diaphragm facing said gaseous fuel pressure adjusting chamber, closer to the center of said circle than said protrusion.

8. An engine generator according to any one of claims 5 to 7, characterized in that the diaphragm is made of an elastic material and a reinforcing base fabric material.

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