1. Field of the Invention
The present invention relates generally to a gas valve unit, and more particularly to a shared valve unit with automatic switch of gas sources according to the input pressures of different gas sources with no need to change the nozzle.
2. Description of Related Art
For an optimum burning state, the pressure of gas supplied to the burner (a gas burning appliance such as a roaster, a toaster, a heating furnace or a water heater) must be stable. The known controlling method to achieve optimum burning state on a burner using different gas sources is to change the nozzle, i.e., different applicable nozzles are used according to the different gas sources.
For example, the gases used by prior-art burners can be classified into two categories: liquefied petroleum gas (LPG) and natural gas (NG). Liquefied petroleum gas and natural gas have different pressures. The pressure of liquefied petroleum gas is higher than that of natural gas. The diameters of gas nozzles applicable to liquefied petroleum gas and natural gas are also different. Therefore, when the gas source of the burner is changed, in order to achieve optimum burning state, a new applicable nozzle shall be installed to suit liquefied petroleum gas or natural gas. This can be difficult, and may even cause a risk of leakage.
The above problem can be solved by a plurality of nozzles adapted to different gas sources pre-installed on the valve unit supplying combustible gases and an automatic control of the valve unit to switch between different gas sources based on different pressures, with no need to change the nozzle. However, up till now, such a preferred design is not seen in the market.
The primary object of the present invention is to provide a shared valve unit with automatic switch of gas sources according to the input pressures of different gas sources with no need to change the nozzle so as to overcome the above-mentioned problem. It is installed with a plurality of nozzles adapted to different gas sources, and can automatically switch between different nozzles based on the different pressures of the input gases. This removes the difficulty to change the nozzle according to different input gases as well as the risk of leakage. Featuring convenience and safety, it indeed has a high practical value.
Thus, to accomplish the above object, the present invention provides a shared valve unit with automatic switch of gas sources according to the input pressures of different gas sources with no need to change the nozzle, comprising a housing, including a base and an upper cap covering the base, with a chamber formed between said base and upper cap, said base extended with a gas flow passage, a gas inlet passage, communicated with the inlet end of said chamber and gas flow passage, a gas outlet passage, communicated with the outlet end of said chamber and gas flow passage; a differential pressure component, configured inside said chamber, including a differential pressure diaphragm, configured on one end of said upper cap corresponding to the base and corresponding to the gas inlet and outlet passages, a controlling device, configured on said differential pressure diaphragm and stretching into the gas outlet passage, with its one end provided with a sealing block to seal the gas outlet passage, an elastic component, abutting between said upper cap and differential pressure diaphragm, such that the sealing block does not seal the gas outlet passage when the differential pressure diaphragm is not subject to gas pressure; a first nozzle, configured inside said gas flow passage; a second nozzle, configured on the outlet end of said gas flow passage, said first nozzle having a smaller diameter than said second nozzle.
Following is further detailed descriptions of the present invention based on examples of multiple preferred embodiments in accompany with drawings:
Firstly, referring to
Said housing 12 is formed by a base 22 and an upper cap 24 relatively covering each other, said base 22 and upper cap 24 forming a chamber 26 therebetween. The inside of said base 22 is extended with a gas flow passage 28 having two openings to form an inlet end 30 and an outlet end 32, for input or output of liquefied petroleum gas (LPG) or natural gas (NG). The middle section of said gas flow passage 28 is provided with a reduced segment 33 with a smaller diameter, a gas inlet passage 34, communicated with said chamber 26 and inlet end 30, a gas outlet passage 36, communicated with said chamber 26 and outlet end 32 at a position adjacent to the reduced segment 30. The end of said gas outlet passage 36 communicated with the chamber 26 is configured with a controlling ring 37. The top end of said upper cap 24 is configured with a screw hole 38.
Said differential pressure component 14, configured inside said chamber 26, comprises a differential pressure diaphragm 40, configured on one end of said base 22 connecting to said upper cap 24, formed by a diaphragm 42 with appropriate elasticity (such as a rubber sheet) and a pressure plate 44 abutting each other, a controlling device 46, configured in the center of said differential pressure diaphragm 40 and going through the controlling ring 37 and extending into the gas outlet passage 36, with its one end configured with a sealing block 48; the outer diameter of said sealing block 48 is larger than the inner diameter of said controlling ring 37, such that when said sealing block 48 abutting the inner edge of said controlling ring 37, the communication between the gas outlet passage 36 and the chamber 26 can be blocked; an adjusting component 50, screwed inside said screw hole 38 and able to move up and down, having an adjusting end 52 and an abutting end 54, said adjusting end 52 can be driven by a tool like screwdriver to enable rotation of said adjusting component 50, a pushing plate 56 and an elastic component 58, located between said adjusting component 50 and pressure plate 44, said abutting end 54 is roughly in a conic shape to abut said pushing plate 56, said elastic component 58 being a spring, such that, when the height position of said adjusting component 50 is changed, the pressing force of said elastic component 58 against the differential pressure diaphragm 40 can be adjusted. The default value of the pressing force of said elastic component 58 against the differential pressure diaphragm 40 is a value sufficient for said differential pressure diaphragm 40 to move and enable said sealing block 48 to seal the gas outlet passage 36 when it is pushed by the liquefied petroleum gas pressure.
Said first nozzle 16, being a standard nozzle for liquefied petroleum gas, is configured on said reduced segment 33 at the position corresponding to the outlet end 32, while said second nozzle 18, being a standard nozzle for natural gas, is configured on said outlet end 32. The outer end of said second nozzle 18 just needs a shape that can be clamped by a tool to lock it into the outlet end 32, including, but not limited to, a hexagonal end that can be clamped by a spanner.
Based on this, the shared valve unit with automatic switch of gas sources according to the input pressures of different gas sources with no need to change the nozzle 10 of the present invention can be connected with gas sources with different pressures. The present embodiment uses natural gas or liquefied petroleum gas as an example, but the types of gas sources are not limited. The operations, features, and efficacies are described below:
When the input gas of said gas flow passage 28 is natural gas (NG), as the gas pressure is lower than the default value of the pressing force of said elastic component 58 against the differential pressure diaphragm 40, said controlling device 46 has no movement, said gas outlet passage 36 and chamber 26 are communicated with each other, as shown in
On the other hand, when the input gas of the gas flow passage 28 is liquefied petroleum gas (LPG), as the gas pressure is larger than the default value of the pressing force of said elastic component 58 against the differential pressure diaphragm 40, it will automatically push up the differential pressure diaphragm 40, and cause the controlling device 46 to move upward, and through the sealing block 48 abutting the inner edge of the controlling ring 37, the communication between said gas outlet passage 36 and chamber 26 is blocked, as shown in
Moreover, the pressing force of said elastic component 58 against the differential pressure diaphragm 40 can be adjusted simply by rotating the adjusting component 50 from said adjusting end 52 with a tool such as a screwdriver, so that said adjusting component 50 moves up or down.
From the above, it is known that the shared valve unit of the present invention is constructed with two nozzles of different diameters, such as a liquefied petroleum gas nozzle and a natural gas nozzle, and can smartly use the pressure difference between different gas sources to keep the differential pressure diaphragm unmoved or cause it to move, so as to automatically switch between different nozzles for gas output, with no need to change the nozzle according to different input gases, and no risk of gas leakage occurring when changing the nozzle. With obvious convenience and safety, it can overcome the existing problems and therefore has practical values.
It is to be noted that, the gas sources of the present invention use natural gas or liquefied petroleum gas for examples, but their types are not limited. As long as there is a difference of input gas pressure standard between the gas sources, the present invention can be used to automatically switch between different gas sources.
Referring to the second preferred embodiment of the present invention shown in
Referring to
Number | Date | Country | Kind |
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103222575 | Dec 2014 | TW | national |