Low-pressure carburizing vacuum furnace heating chamber capable of quickly exchanging air

Abstract

The utility model relates to the technical field of low-pressure carburization, and discloses a low-pressure carburization vacuum furnace heating chamber capable of quickly exchanging air, which comprises a vacuum furnace provided with a heating module, a furnace cover hinged to the top and a bracket I arranged at the bottom, an air inlet pressure regulating chamber is arranged below the vacuum furnace, the air inlet pressure regulating chamber is connected with the vacuum furnace through a uniform air distribution module, a plurality of air delivery pipes are arranged at the top of the air inlet pressure regulating chamber, the air inlet pressure regulating chamber is connected with a nitrogen source, a carbon source and an air purification module through the air delivery pipes, and a preheating module is arranged in the air inlet pressure regulating chamber; an exhaust pressure regulating chamber is arranged on one side of the vacuum furnace, a vacuum pump is arranged on the vacuum furnace, an exhaust port of the vacuum pump is connected with the exhaust pressure regulating chamber, and an exhaust pump is arranged on the exhaust pressure regulating chamber. Compared with the prior art, the device has the advantages that the pressure difference of the two sides of the vacuum pump can be regulated and controlled, gas in the vacuum furnace can be conveniently and rapidly exhausted, the gas exchange speed in the vacuum furnace is higher, and the gas exchange efficiency is higher.

Description

Technical Field

[0001] This utility model relates to the field of low-pressure carburizing technology, specifically to a heating chamber for a low-pressure carburizing vacuum furnace with rapid air exchange. Background Technology

[0002] A low-pressure carburizing vacuum furnace is a device that performs gas carburizing under conditions below one atmosphere. It is mainly used for surface treatment of metal parts. By operating under vacuum, high-purity acetylene and other carburizing media are introduced into the furnace in a pulse manner to perform rapid carburizing. At the same time, the vacuum environment reduces the contact between the metal surface and oxygen at high temperatures, thus reducing oxidation and improving the hardness and wear resistance of the metal parts.

[0003] Existing low-pressure carburizing vacuum furnaces on the market often simply use a vacuum pump to evacuate air, thereby reducing the gas pressure inside the furnace and creating a vacuum. However, if the pressure difference between the two sides of the vacuum pump is too large, the evacuation efficiency will decrease rapidly, resulting in a slow gas exchange rate. This will have an adverse effect on the overall heat treatment effect of the metal parts. Furthermore, when acetylene and nitrogen are introduced for processing, the large temperature difference between the gas medium and the metal parts will affect the vacuum heating effect of the metal parts. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the above-mentioned technical difficulties and provide a heating chamber for a low-pressure carburizing vacuum furnace with rapid air exchange. It is equipped with an exhaust pressure regulating chamber, which can regulate the pressure difference between the inlet and outlet of the vacuum pump, so as to facilitate the rapid discharge of gas in the vacuum furnace. It can also preheat the gas medium entering the vacuum furnace to reduce the temperature difference with the metal parts.

[0005] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0006] A heating chamber for a low-pressure carburizing vacuum furnace with rapid air exchange includes a vacuum furnace, a heating module, a furnace cover hinged to the top, and a support frame at the bottom.

[0007] The vacuum furnace is provided with an air inlet pressure regulating chamber below it, and the air inlet pressure regulating chamber is connected to the vacuum furnace through a uniform gas distribution module. Multiple gas supply pipes are provided on the top of the air inlet pressure regulating chamber, and are respectively connected to a nitrogen source, a carbon source and an air purification module through the gas supply pipes. A preheating module is provided inside the air inlet pressure regulating chamber.

[0008] An exhaust pressure regulating chamber is provided on one side of the vacuum furnace. A vacuum pump is installed on the vacuum furnace, and the exhaust port of the vacuum pump is connected to the exhaust pressure regulating chamber. An exhaust pump is installed on the exhaust pressure regulating chamber.

[0009] As an improvement, the preheating module includes a heat-conducting baffle arranged circumferentially in the intake pressure regulating chamber, and a heater is provided on the outer wall of the heat-conducting baffle.

[0010] As an improvement, an intake piston is provided in the intake pressure regulating chamber. The intake piston is slidably disposed inside the heat-conducting baffle and is sealed with the heat-conducting baffle. An intake electric actuator is provided at the bottom of the intake pressure regulating chamber, and the extension end of the intake electric actuator is connected to the intake piston.

[0011] As an improvement, an exhaust piston is slidably installed in the exhaust pressure regulating chamber, and an exhaust electric actuator is installed at the top, with the extension end of the exhaust electric actuator connected to the exhaust piston.

[0012] As an improvement, the uniform gas distribution module includes a gas distribution box and a gas distribution pipe; the gas distribution box is located at the bottom of the vacuum furnace, and an air inlet pipe is provided at the bottom. A valve is provided on the air inlet pipe, and the bottom is connected to the air inlet pressure regulating chamber. One end of the gas distribution pipe is connected to the gas distribution box, and the other end is connected to the vacuum furnace. Multiple gas distribution pipes are evenly arranged circumferentially on the gas distribution box, so that the gas medium enters the vacuum furnace evenly.

[0013] As an improvement, the air purification module includes an air pump connected to the air supply pipe and a filter connected to the air inlet of the air pump. The bottom of the side wall of the filter is provided with an air exchange hole and a filter element is provided inside.

[0014] The advantages of this utility model compared with the prior art are as follows:

[0015] 1. This utility model is equipped with an exhaust pressure regulating chamber. The exhaust piston can be controlled to slide up and down by the exhaust electric push rod to change the gas pressure in the exhaust pressure regulating chamber, thereby regulating the pressure difference between the inlet and outlet of the vacuum pump. This facilitates the rapid discharge of gas from the vacuum furnace, resulting in faster gas exchange speed and higher gas exchange efficiency in the vacuum furnace.

[0016] 2. This utility model is equipped with an inlet pressure regulating chamber, which can control the pressure of the gas medium entering the vacuum furnace by controlling the speed of the inlet piston sliding up and down, thereby adjusting the speed of the gas medium entering the vacuum furnace and improving the uniformity and effectiveness of carburizing of metal parts.

[0017] 3. The gas inlet pressure regulating chamber of this utility model is equipped with a heater, which can heat the gas medium that has entered the gas inlet pressure regulating chamber in advance, reduce the temperature difference between the gas medium and the vacuum furnace, and reduce the impact of the gas medium on high-temperature metal parts after entering the vacuum furnace. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0020] Figure 3 This is a structural schematic diagram of the uniform air distribution module of this utility model.

[0021] Figure 4 This is a schematic diagram of the air intake pressure regulating chamber of this utility model.

[0022] Figure 5 This is a cross-sectional schematic diagram of the exhaust pressure regulating chamber of this utility model.

[0023] As shown in the figure: 1. Vacuum furnace; 2. Furnace cover; 3. Inlet pressure regulating chamber; 4. Exhaust pressure regulating chamber; 5. Gas distribution box; 6. Gas distribution pipe; 7. Inlet pipe; 8. Exhaust piston; 9. Exhaust electric actuator; 10. Exhaust piston; 11. Inlet electric actuator; 12. Heat-conducting baffle; 13. Heater; 14. Gas delivery pipe; 15. Gas pump; 16. Filter; 17. Vacuum pump; 18. Exhaust pump; 19. Support 2; 20. Support 1. Detailed Implementation

[0024] In the description of this utility model, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] A heating chamber for a low-pressure carburizing vacuum furnace with rapid air exchange, such as... Figure 1 , Figure 2 As shown, specifically including

[0027] Vacuum furnace 1 is equipped with a heating system, temperature sensor, and pressure sensor. It is open at the top and hinged to a furnace cover 2. When the furnace cover 2 is closed, the vacuum furnace 1 is completely sealed. A support 20 is provided at the bottom. A uniform gas distribution module and an inlet pressure regulating chamber 3 are provided below the vacuum furnace 1 and are connected to the inlet pressure regulating chamber 3 through the uniform gas distribution module. An exhaust pressure regulating chamber 4 is provided at the rear of the vacuum furnace 1. The exhaust pressure regulating chamber 4 is a sealed cavity and is supported by a support 19 at the bottom. A vacuum pump 17 is provided on the side wall of the vacuum furnace 1 and the exhaust port of the vacuum pump 17 is connected to the top of the exhaust pressure regulating chamber 4. An exhaust pump 18 is also provided at the top of the exhaust pressure regulating chamber 4. Pressure sensors are provided in the inlet pressure regulating chamber 3 and the exhaust pressure regulating chamber 4 respectively.

[0028] Uniform air distribution module, such as Figure 3 As shown, it includes a gas distribution box 5 and a gas distribution pipe 6; the gas distribution box 5 is located at the bottom of the vacuum furnace 1, and an air inlet pipe 7 is provided at the bottom. A valve is provided on the air inlet pipe 7, and the bottom is connected to the air inlet pressure regulating chamber 3. One end of the gas distribution pipe 6 is connected to the side wall of the gas distribution box 5, and the other end is connected to the side wall of the vacuum furnace 1. Eight gas distribution pipes are evenly arranged on the gas distribution box 5 along the circumference.

[0029] Inlet pressure regulating chamber 3 Figure 4 As shown, a ring-shaped heat-conducting baffle 12 is arranged circumferentially on the inner side of the chamber, and the top and bottom of the heat-conducting baffle 12 are connected to the intake pressure regulating chamber 3 respectively. A heater 13 is arranged on the outer wall of the heat-conducting baffle 12. An intake piston 10 is arranged in the intake pressure regulating chamber 3, and the intake piston 10 is slidably arranged in the heat-conducting baffle 12 and sealed with the heat-conducting baffle 12. An intake electric actuator 11 is arranged at the bottom of the intake pressure regulating chamber 3, and the extension end of the intake electric actuator 11 is connected to the intake piston 10. After the intake electric actuator 11 extends or retracts, the intake piston 10 is in the heat-conducting baffle. The air inlet pressure regulating chamber 3 has three air supply pipes 14 at the top (the connection points of the air supply pipes 14 are located inside the heat-conducting partition 12), and are respectively connected to the nitrogen source, carbon source (i.e., high-purity acetylene) and air purification module through the air supply pipes 14. Each air supply pipe 14 is equipped with a valve and a check valve. The air purification module includes an air supply pump 15 connected to the air supply pipe 14 and a filter 16 connected to the air inlet of the air supply pump 15. The filter 16 is arranged below the exhaust pressure regulating chamber 4, and the lower half of the side wall is reserved with ventilation holes and has a filter element inside.

[0030] Exhaust pressure regulating chamber 4 Figure 5 As shown, an exhaust piston 8 is slidably installed inside the chamber, and the inner wall is sealed to the exhaust piston 8. An exhaust electric push rod 9 is installed at the top, and the extension end of the exhaust electric push rod 9 is connected to the exhaust piston 8. After the exhaust electric push rod 9 extends or retracts, the exhaust piston 8 slides up and down in the exhaust pressure regulating chamber 4.

[0031] In the specific implementation of this embodiment:

[0032] Low-pressure carburizing process using this invention:

[0033] After opening the furnace cover 2 and placing the metal parts into the vacuum furnace 1, close the furnace cover 2, turn on the exhaust pump 18 and the vacuum pump 17 to exhaust the gas. Once the pressure inside the vacuum furnace 1 is low, turn off the vacuum pump 17 and control the exhaust electric push rod 9 to retract, causing the exhaust piston 8 to slide to the upper side of the exhaust pressure regulating chamber 4 (leaving some air). Then turn off the exhaust pump 18 and control the exhaust electric push rod 9 to extend, causing the exhaust piston 8 to slide to the lower side of the exhaust pressure regulating chamber 4. This increases the space above the exhaust piston 8 in the exhaust pressure regulating chamber 4, reducing the air pressure and thus lowering the pressure difference between the inlet and outlet of the vacuum pump 17. This allows the remaining gas in the vacuum furnace 1 to be quickly discharged into the exhaust pressure regulating chamber 4, creating a vacuum state inside the vacuum furnace 1. Turn on the exhaust pump 18 and control the exhaust electric push rod 9 to retract, allowing the gas in the exhaust pressure regulating chamber 4 to be discharged.

[0034] Turn on the heating system inside vacuum furnace 1 to heat the metal parts under vacuum conditions.

[0035] Open the corresponding gas supply pipe 14 valve to inject a certain amount of high-purity acetylene (carbon source) and nitrogen into the inlet pressure regulating chamber 3 (nitrogen is used to regulate the gas pressure). Turn on the heater 13 to heat the gas in the inlet pressure regulating chamber 3. During the process, control the extension and retraction of the inlet electric actuator 11 according to the pressure of the inlet pressure regulating chamber 3 to change the position of the inlet piston 10, so that the pressure in the inlet pressure regulating chamber 3 remains safe and stable. After heating is completed, adjust the gas pressure in the inlet pressure regulating chamber 3 to the set value for entering the vacuum furnace 1 by extending and retracting the inlet electric actuator 11.

[0036] Open the valve of the air inlet pipe 7 so that the gas in the air inlet pressure regulating chamber 3 can enter the vacuum furnace 1 evenly through the air distribution box 5 and the air distribution pipe 6. The pressure in the air inlet pressure regulating chamber 3 can be kept stable by the extension and retraction of the air inlet electric push rod 11, so that the gas enters the vacuum furnace 1 at a stable speed and reacts with the surface of the metal parts at high temperature, resulting in carburization.

[0037] After a certain reaction time, the valve of the inlet pipe 7 is closed, and the exhaust electric push rod 9 is extended to reduce the gas pressure in the exhaust pressure regulating chamber 4. Then, the vacuum pump 17 is turned on to transfer the remaining gas and reaction gas in the vacuum furnace 1 to the exhaust pressure regulating chamber 4 and discharge them through the exhaust pump 18. This process is repeated multiple times to increase the carburization depth on the surface of the metal parts.

[0038] Nitrogen or purified air is introduced to cool the metal parts. After cooling is complete, the furnace cover 2 is opened to recycle the carburized metal parts.

[0039] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A low-pressure carburizing vacuum furnace heating chamber capable of rapid ventilation, comprising a vacuum furnace (1) provided with a heating module, a furnace cover (2) hinged to the top, and a support (20) provided at the bottom, characterized in that: a gas inlet pressure regulating chamber (3) is arranged below the vacuum furnace (1), and the gas inlet pressure regulating chamber (3) and the vacuum furnace (1) are connected through a uniform gas distribution module, a plurality of gas conveying pipes (14) are arranged at the top of the gas inlet pressure regulating chamber (3) and connected with a nitrogen source, a carbon source and an air purification module respectively through the gas conveying pipes (14), and a preheating module is arranged in the gas inlet pressure regulating chamber (3); an exhaust gas pressure regulating chamber (4) is arranged on one side of the vacuum furnace (1), a vacuum pump (17) is arranged on the vacuum furnace (1), and the exhaust port of the vacuum pump (17) is connected with the exhaust gas pressure regulating chamber (4), and an exhaust pump (18) is arranged on the exhaust gas pressure regulating chamber (4). The preheating module comprises a heat-conducting partition plate (12) arranged circumferentially in the gas inlet pressure regulating chamber (3), and a heater (13) is arranged on the outer side wall of the heat-conducting partition plate (12).

2. The low-pressure carburizing vacuum furnace heating chamber capable of rapid aeration according to claim 1, characterized in that: An inlet piston (10) is arranged in the gas inlet pressure regulating chamber (3), the inlet piston (10) is arranged in the heat-conducting partition plate (12) in a sliding manner, and is sealed with the heat-conducting partition plate (12), an inlet electric push rod (11) is arranged at the bottom of the gas inlet pressure regulating chamber (3), and the extension end of the inlet electric push rod (11) is connected with the inlet piston (10).

3. The low-pressure carburizing vacuum furnace heating chamber capable of rapid aeration according to claim 2, characterized in that: An exhaust piston (8) is arranged in the exhaust gas pressure regulating chamber (4) in a sliding manner, an exhaust electric push rod (9) is arranged at the top, and the extension end of the exhaust electric push rod (9) is connected with the exhaust piston (8).

4. The low-pressure carburizing vacuum furnace heating chamber capable of rapid aeration according to claim 1, characterized in that: The uniform gas distribution module comprises a gas distribution box (5) and a gas distribution pipe (6), the gas distribution box (5) is arranged at the bottom of the vacuum furnace (1), and an inlet pipe (7) is arranged at the bottom, a valve is arranged on the inlet pipe (7), and the bottom is connected with the gas inlet pressure regulating chamber (3), one end of the gas distribution pipe (6) is connected with the gas distribution box (5), the other end is connected with the vacuum furnace (1), and a plurality of gas distribution pipes (6) are arranged circumferentially and uniformly on the gas distribution box (5).

5. The low-pressure carburizing vacuum furnace heating chamber capable of rapid aeration according to claim 1, characterized in that: The air purification module comprises a gas conveying pump (15) connected with the gas conveying pipe (14), and a filter (16) connected with the gas inlet of the gas conveying pump (15).

6. The low-pressure carburizing vacuum furnace heating chamber capable of rapid aeration according to claim 1, characterized in that: ​

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