Flame type inner hole heating device

Abstract

The utility model relates to the technical field of machining, in particular to a flame type inner hole heating device which comprises a base, a gas mixing cavity is arranged above the base, a first gas inlet and a second gas inlet are formed in the bottom of the gas mixing cavity, a plurality of exhaust ports are distributed on the side wall of the gas mixing cavity in the circumferential direction, and the exhaust ports are communicated with inlets of spraying branch pipes. Outlets of the spraying branch pipes are communicated with an air inlet in the inner side of the annular pipe, an airflow spraying opening is formed in the outer side of the annular pipe and corresponds to the air inlet in the inner side of the annular pipe, and an airflow nozzle is installed on the airflow spraying opening. According to the utility model, the flame heating efficiency is improved, and the pressure difference of mixed gas entering each airflow nozzle is reduced, so that a heated workpiece is more uniformly heated.

Description

Technical Field

[0001] The utility model relates to the technical field of machining, in particular to a flame-type inner hole heating device. Background Art

[0002] The hot shrinking process is an important metal processing technology. This technology utilizes the principle of thermal expansion and contraction. First, the containing part is heated to make it expand, and then the heated and expanded containing part is quickly assembled onto the contained part. After the containing part cools and shrinks, a tight fit between the containing part and the contained part is achieved. Compared with traditional assembly methods, the hot shrinking process has the advantages of fast assembly speed and high assembly quality. It can complete the assembly work in a short time, and at the same time improve the performance stability, wear resistance, sealing performance and mechanical strength of the connecting parts, and is widely used in the fields of machinery manufacturing, aerospace, automotive industry and manufacturing, etc.

[0003] In the hot shrinking process, the most commonly used heating methods include flame heating method, resistance heating method and electromagnetic induction heating method. The resistance heating method uses a resistance wire as the heating element and generates heat by the resistance heat effect during the conduction process of the resistance wire. The resistance heating method has the advantage of uniform heating, but the equipment cost is high, and since resistance heating needs to contact the surface of the metal workpiece, there is a risk of oxidation or discoloration on the contact surface between the metal workpiece and the heating element. The electromagnetic induction heating method uses a changing magnetic field to induce eddy currents in the metal workpiece and generates heat through electromagnetic induction. The electromagnetic induction heating method has the advantages of fast heating speed and non-contact heating, but it requires special power supplies and coils, the equipment cost is high and it is only applicable to materials with good conductivity. The flame heating method uses fuels such as gas, liquefied gas or liquefied petroleum gas as the heat source and generates heat through gas combustion. The flame heating method has the advantages of fast heating speed and low equipment cost, but there is a problem of uneven heating. Summary of the Utility Model

[0004] Aiming at the technical problem of uneven heating in the prior art when using the flame heating method for hot shrinking, the utility model provides a flame-type inner hole heating device, which conveys a mixed gas of combustible gas and combustion-supporting gas from a gas mixing chamber arranged inside the annular tube to an air flow nozzle arranged outside the annular tube, improving the efficiency of flame heating, and at the same time helping to reduce the pressure difference of the mixed gas entering each air flow nozzle, making the heated workpiece heated more evenly.

[0005] The technical solution of the utility model is as follows:

[0006] A flame-type inner hole heating device includes a base. Above the base, a gas mixing chamber is provided. At the bottom of the gas mixing chamber, a first air inlet and a second air inlet are opened. A number of exhaust ports are circumferentially distributed on the side wall of the gas mixing chamber. The exhaust ports are connected to the inlets of injection branch pipes. The outlets of the injection branch pipes are connected to the inlets on the inner side of an annular pipe. On the outer side of the annular pipe, air flow injection ports are provided. The air flow injection ports correspond to the inlets on the inner side of the annular pipe. Air flow nozzles are installed on the air flow injection ports.

[0007] Further, the upper end of the base is rotatably connected to the lower end of a telescopic rod, and the upper end of the telescopic rod is fixedly connected to the lower end of the gas mixing chamber. A rotating shaft is fixed to the upper end of the base, and the rotating shaft is rotatably connected to the lower end of the telescopic rod through a bearing.

[0008] Further, the gas mixing chamber is a hollow cylinder. A partition can be longitudinally arranged inside the gas mixing chamber. The lower end of the partition is fixed to the inner bottom of the gas mixing chamber, and there is a gap between the upper end of the partition and the inner top of the gas mixing chamber. The partition divides the lower part inside the gas mixing chamber into a first chamber and a second chamber.

[0009] Further, the first air inlet is connected to the delivery pipeline of combustible gas, and the second air inlet is connected to the delivery pipeline of combustion-supporting gas. The combustible gas and the combustion-supporting gas respectively enter the first chamber and the second chamber through the first air inlet and the second air inlet, and then are mixed above the inside of the gas mixing chamber.

[0010] Further, flow regulating valves are respectively arranged between the first air inlet and the delivery pipeline of combustible gas, and between the second air inlet and the delivery pipeline of combustion-supporting gas. The flow rates of the combustible gas and the combustion-supporting gas entering the gas mixing chamber can be respectively regulated through the flow regulating valves.

[0011] Further, a backfire prevention device is arranged at the air flow injection ports.

[0012] Further, the exhaust ports are evenly distributed along the side wall of the gas mixing chamber.

[0013] Further, the air flow nozzles are telescopic nozzles, and the telescopic nozzles can adjust the length according to the inner hole diameter of the workpiece to be heated.

[0014] Further, the axis of the gas mixing chamber passes through the center of the annular pipe.

[0015] Further, both the air flow nozzles and the flow regulating valves are electrically connected to a remote control system.

[0016] The beneficial effects of the present utility model are as follows:

[0017] A flame-type inner hole heating device provided by the present utility model arranges a gas mixing chamber inside an annular pipe and uses injection branch pipes to connect the gas mixing chamber and the annular pipe. The mixed gas output from the gas mixing chamber can be simultaneously and directly transported to the air flow nozzles through the injection branch pipes, effectively shortening the pipe length of the mixed gas entering the air flow nozzles, improving the transportation efficiency of the mixed gas, and at the same time helping to reduce the pressure difference of the mixed gas entering each air flow nozzle, making the heated workpiece heated more evenly. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a top view of the flame-type inner hole heating device in Embodiment 1.

[0020] Figure 2 It is a partial schematic diagram of the flame-type inner hole heating device in Embodiment 1.

[0021] In the figure, 1 - air flow nozzle, 2 - annular pipe, 3 - injection branch pipe, 4 - gas mixing chamber, 5 - exhaust port, 6 - delivery pipeline for combustible gas, 7 - delivery pipeline for combustion-supporting gas, 8 - telescopic rod, 9 - rotating table, 10 - base. Detailed Embodiments

[0022] In order to enable those in the technical field to better understand the technical solutions in the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0023] Embodiment 1

[0024] A flame-type inner hole heating device, as Figure 1 and Figure 2As shown, it includes a base 10, a rotating shaft is fixed on the upper end of the base 10, and the rotating shaft is rotatably connected to the rotating table 9 through a bearing, and the upper end of the rotating table 9 is fixedly connected to the lower end of the telescopic rod 8. A gas mixing chamber 4 is arranged above the base 10. The gas mixing chamber 4 is a hollow cylinder, and a partition is longitudinally arranged inside the gas mixing chamber 4. The lower end of the partition is fixed to the inner bottom of the gas mixing chamber 4, and a gap is left between the upper end of the partition and the inner top of the gas mixing chamber 4. The partition divides the lower part of the gas mixing chamber 4 into a first chamber and a second chamber. The bottom of the gas mixing chamber is provided with a first air inlet and a second air inlet. The first air inlet is located at the bottom of the first chamber, and the first air inlet is connected to the conveying pipeline 6 of the combustible gas; the second air inlet is located at the bottom of the second chamber, and the second air inlet is connected to the conveying pipeline 7 of the combustion-supporting gas. A combustible gas flow regulating valve and a combustion-supporting gas flow regulating valve are respectively arranged between the first air inlet and the conveying pipeline 6 of the combustible gas, and between the second air inlet and the conveying pipeline 7 of the combustion-supporting gas. The combustible gas and the combustion-supporting gas enter the first chamber and the second chamber through the first air inlet and the second air inlet respectively, and then mix above the interior of the gas mixing chamber 4. Eight exhaust ports 5 are evenly distributed on the side wall of the gas mixing chamber 4 in the circumferential direction, and the eight exhaust ports 5 are respectively connected to the inlet of the corresponding injection branch pipe 3, and the outlet of the injection branch pipe 3 is connected to the air inlet on the inner side of the annular tube 2. An airflow injection port is arranged on the outer side of the annular tube 2, and the airflow injection port corresponds to the air inlet on the inner side of the annular tube. An anti-backfire device is arranged on the airflow injection port, and an airflow nozzle 1 is installed on the airflow injection port, and the airflow nozzle 1 is a retractable nozzle. The axis of the gas mixing chamber 4 passes through the center of the annular tube 2.

[0025] Instructions for use: When it is necessary to heat-shrink the inner hole of the thicker containment, first place the flame-type inner hole heating device on the inner hole axis of the containment, adjust the length of the airflow nozzle and the length of the telescopic rod according to the actual situation of the containment and the requirements of heat-shrinking, determine the distance between the airflow nozzle on the outside of the annular tube and the inner side surface of the containment to be heated, and ensure that the airflow nozzle on the outside of the annular tube and the part to be heated of the containment are at the same height. Then use the combustible gas flow regulating valve and the combustion-supporting gas flow regulating valve to regulate the flow of the combustible gas and the flow of the combustion-supporting gas entering the gas mixing chamber, and adjust the heating temperature by controlling the flow ratio of the combustible gas and the combustion-supporting gas entering the gas mixing chamber. The combustible gas and the combustion-supporting gas entering the gas mixing chamber are mixed above the inside of the gas mixing chamber, and then transported to the annular tube through the injection branch pipe. The mixed gas in the annular tube is then ejected by the airflow nozzle to cause a combustion reaction.

[0026] Although the present utility model has been described in detail by referring to the attached drawings and in conjunction with the preferred embodiments, the present utility model is not limited thereto. Without departing from the spirit and essence of the present utility model, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present utility model, and all such modifications or substitutions should fall within the scope of the present utility model. / Any person skilled in the art within the technical scope disclosed by the present utility model can easily conceive of changes or substitutions, which should all be covered within the protection scope of the present utility model.

Claims

1. A flame-type inner hole heating device, comprising a base, characterized in that, A gas mixing chamber is arranged above the base. A first air inlet and a second air inlet are opened at the bottom of the gas mixing chamber. A plurality of exhaust ports are circumferentially distributed on the side wall of the gas mixing chamber. The exhaust ports are communicated with the inlets of the injection branch pipes. The outlets of the injection branch pipes are communicated with the inlets inside the annular pipe. An air flow injection port is arranged on the outside of the annular pipe. The air flow injection port corresponds to the inlet inside the annular pipe. An air flow nozzle is installed on the air flow injection port.

2. The flame type inner hole heating device according to claim 1, characterized in that, The upper end of the base is rotatably connected to the lower end of the telescopic rod, and the upper end of the telescopic rod is fixedly connected to the lower end of the gas mixing chamber.

3. The flame type inner hole heating device according to claim 1, characterized in that, The gas mixing chamber is a hollow cylinder.

4. A flame-type inner hole heating device according to claim 1, characterized in that, The first air inlet is communicated with the pipeline for transporting combustible gas, and the second air inlet is communicated with the pipeline for transporting combustion-supporting gas.

5. The flame type inner hole heating device according to claim 4, characterized in that, Flow regulating valves are respectively arranged between the first air inlet and the pipeline for transporting combustible gas, and between the second air inlet and the pipeline for transporting combustion-supporting gas.

6. A flame-type inner hole heating device according to claim 1, characterized in that, A backfire prevention device is arranged at the air flow injection port.

7. The flameless internal hole heating device according to claim 1, wherein, The exhaust ports are evenly distributed along the side wall of the gas mixing chamber.

8. A flame type inner hole heating device according to claim 1, characterized in that, The air flow nozzle is a telescopic nozzle.

9. The flame-type inner hole heating device according to claim 1, characterized in that, The axis of the gas mixing chamber passes through the center of the annular pipe.

10. A flame-type inner hole heating device as described in claim 5, characterized in that, Both the air flow nozzle and the flow regulating valve are electrically connected to the remote control system.

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