Pneumatic proportional valve

Abstract

The pneumatic proportional valve comprises a valve body, a hollow piston and a spring, an argon inlet and a mixed gas outlet are formed in the two sides of the valve body respectively, a carbon dioxide inlet is formed in the top of the valve body, and a mixing flow channel communicated with the argon inlet and the mixed gas outlet is formed in the valve body. An annular cavity and a cylindrical cavity are axially formed in the middle of the mixing flow channel, the cylindrical cavity is wrapped in the annular cavity, the carbon dioxide inlet is communicated with the annular cavity, the hollow piston is axially connected into the cylindrical cavity in a sliding mode, a spring is arranged in the hollow piston, and the spring forces the hollow piston to be close to one side of the argon inlet. In the welding process, the gas mixing proportion is not affected, cooling is conducted only through carbon dioxide in the cooling process, and therefore the purpose of saving argon is achieved. The gas proportion is adjusted through movement of the hollow piston in the welding process, the hollow piston is forced to reset through the spring in the cooling process, and the proportion of argon and carbon dioxide in the whole process is automatically switched.

Description

TECHNICAL FIELD

[0001] The utility model relates to proportional valve technical field especially is related to a kind of pneumatic proportional valve. BACKGROUND

[0002] The protective gas used in welding process is mostly carbon dioxide mixed gas, which is composed of 80% argon and 20% carbon dioxide. In the automatic welding process, argon and carbon dioxide are mixed and sprayed from the welding gun nozzle, thereby protecting the molten pool and high-temperature metal. After welding is completed, the gas delay closing cools the high-temperature welding gun and welding wire, thereby preventing the welding wire from forming an oxidation layer that prevents the arc from being generated. However, the cooling of the welding gun and welding wire can also be achieved using only carbon dioxide gas. Currently, the proportion of argon and carbon dioxide gas cannot be adjusted during the delay closing process, so the cooling process results in waste of argon. Therefore, a pneumatic proportional valve is designed to solve the problem of argon waste. SUMMARY

[0003] To overcome the shortcomings of existing proportional valves, the utility model aims to provide a pneumatic proportional valve that saves argon and automatically switches gas proportions.

[0004] To achieve the above-mentioned purpose, one technical solution adopted by the utility model is: a pneumatic proportional valve, comprising a valve body, a hollow piston, and a spring. The valve body has an argon inlet and a mixed gas outlet on both sides. The valve body has a carbon dioxide inlet on the top. The valve body has a mixed flow channel that connects the argon inlet and the mixed gas outlet. The mixed flow channel has an annular cavity and a cylindrical cavity in the middle. The annular cavity covers the cylindrical cavity. The carbon dioxide inlet is connected to the annular cavity. The hollow piston is axially connected to the cylindrical cavity. The hollow piston has a spring inside. The spring forces the hollow piston to move closer to the argon inlet.

[0005] Preferably, the hollow piston has a first through hole on the side facing the argon inlet. The diameter of the first through hole is smaller than the diameter of the argon inlet. The hollow piston has multiple second through holes radially.

[0006] Further preferably, the first through hole has a gas flow rate of h1, and the multiple second through holes have a gas flow rate of h2, where h1:h2=8:2.

[0007] Preferably, the hollow piston compresses the spring to block the annular cavity when the argon inlet is venting.

[0008] Preferably, the argon inlet has a higher gas inlet pressure than the carbon dioxide inlet.

[0009] The utility model discloses a beneficial effect is: 1, in the welding process gas mixture ratio is not affected, cooling process only relies on carbon dioxide cooling, thereby realizes the purpose of saving argon;2, in the welding process, the adjustment of gas ratio is realized through the movement of hollow piston, and the hollow piston resets through spring in the cooling process, and the matching of argon and carbon dioxide gas in the whole process realizes automatic switching through air pressure. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is the welding state section structure view of the utility model;

[0011] Figure 2 It is the welding completion state section structure view of the utility model;

[0012] Figure 3 、 4 It is the three-dimensional structure view of hollow piston of the utility model. DETAILED DESCRIPTION

[0013] The preferable embodiments of the utility model are described in detail below in combination with the drawings, so that the advantages and characteristics of the utility model can be more easily understood by the person skilled in the art, and the protection scope of the utility model can be more clearly and explicitly defined.

[0014] It should be noted that in the description of the utility model, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the direction or positional relationship terms based on the direction or positional relationship shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation of the utility model.

[0015] In addition, it should also be noted that in the description of the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "providing", "setting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements. For the person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0016] Please refer to Figures 1 to 4 , the utility model embodiment includes:

[0017] A kind of pneumatic proportional valve, including valve body 1, hollow piston 2 and spring 3, the valve body 1 two sides respectively with argon inlet 4 and mixed gas outlet 5, the valve body 1 top has carbon dioxide inlet 6, the valve body 1 with the mixed flow channel 11 that is communicated argon inlet 4 and mixed gas outlet 5, the mixed flow channel 11 middle part is axially provided with ring cavity 12 and cylindrical cavity 13, the ring cavity 12 is covered in cylindrical cavity 13, the carbon dioxide inlet 6 is communicated with ring cavity 12, the hollow piston 2 is axially slidably connected in cylindrical cavity 13, spring 3 is arranged in the hollow piston 2, the spring 3 forces hollow piston 2 to be close to argon inlet 4 side;

[0018] The hollow piston 2 side facing argon inlet 4 has first through hole 21, the first through hole 21 aperture is smaller than argon inlet 4 aperture, the hollow piston 2 radially has a plurality of second through holes 22;

[0019] The first through hole 21 passes through gas flow h1, and the plurality of second through holes 22 pass through gas flow h2, wherein h1:h2=8:2;

[0020] The hollow piston 2 compresses spring 3 to block ring cavity 12 when argon inlet 4 is ventilated;

[0021] The argon inlet 4 inlet pressure is greater than the carbon dioxide inlet 6 inlet pressure;

[0022] Through the above setting, in actual working process, its specific working principle is as follows:

[0023] First, the argon inlet 4 and carbon dioxide inlet 6 of the valve are communicated with the gas supply end, the mixed gas outlet 5 of the valve is communicated with the gas inlet of the welding gun, in the welding process, the argon gas supply end and the carbon dioxide gas supply end supply gas simultaneously, due to the first through hole 21 on the side of the hollow piston 2 aperture is smaller than the argon inlet 4 aperture, so that the argon gas flows through the first through hole 21 and generates a pressure difference, thereby pushing the hollow piston 2 to compress the spring 3 to block the ring cavity 12, at this time, the carbon dioxide can only pass through the second through hole 22 radially of the hollow piston 2 and enter the mixed flow channel 11, and the mixed gas is sprayed from the welding gun nozzle, thereby protecting the molten pool and high-temperature metal;

[0024] After completing welding, the argon gas supply end stops supplying gas, the carbon dioxide gas supply end is delayed to close, at this time, the spring 3 forces the cylindrical piston to return to the cylindrical cavity 13, so as not to block the ring cavity 12, the argon inlet 4 is in a blocked state, so that the carbon dioxide gas is sprayed from the welding gun nozzle through the ring cavity 12 and the mixed flow channel 11, thereby the welding gun and welding wire can be cooled, to prevent the welding wire from forming an oxidation layer to cause the arc to be unable to generate;

[0025] In the welding process, the gas mixing ratio is not affected, and the cooling process is cooled only by carbon dioxide, thereby saving the use of argon and not affecting the mixing ratio of the mixed gas;

[0026] The above only describes the embodiments of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A pneumatic proportional valve, characterized in that, The device includes a valve body, a hollow piston, and a spring. The valve body has an argon inlet and a mixed gas outlet on both sides, and a carbon dioxide inlet at the top. The valve body has a mixing channel connecting the argon inlet and the mixed gas outlet. An annular cavity and a cylindrical cavity are axially arranged in the middle of the mixing channel. The annular cavity encloses the cylindrical cavity. The carbon dioxide inlet and the annular cavity are connected. The hollow piston is axially slidably connected to the cylindrical cavity. A spring is installed inside the hollow piston, and the spring forces the hollow piston to move closer to the argon inlet side.

2. The pneumatic proportional valve according to claim 1, characterized in that, The hollow piston has a first through hole on the side facing the argon inlet, the diameter of the first through hole being smaller than the diameter of the argon inlet, and the hollow piston has multiple second through holes radially.

3. A pneumatic proportional valve according to claim 2, characterized in that, The gas flow rate through the first through-hole is h1, and the gas flow rate through the multiple second through-holes is h2, where h1:h2 = 8:

2.

4. A pneumatic proportional valve according to claim 1, characterized in that, The hollow piston compresses the spring to seal the annular cavity when argon gas is introduced.

5. A pneumatic proportional valve according to claim 1, characterized in that, The argon inlet pressure is greater than the carbon dioxide inlet pressure.

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