Cavity sealing device suitable for induction heating in closed cavity

Abstract

The invention discloses a cavity sealing device suitable for induction heating in a closed cavity, which comprises a ceramic substrate, the ceramic substrate is hermetically connected with the closed cavity, a first pipe fitting and a second pipe fitting are respectively arranged on the left side and the right side of the ceramic substrate, gaps are formed between the first pipe fitting and the ceramic substrate to form a cavity, and first, second and third sealing rings are arranged; the end part of the first pipe fitting is provided with an elastic structure which is in contact with the second pipe fitting, the first pipe fitting and the second pipe fitting are also connected with the fastener and are of split conical structures which are hollow and communicated, and the inner diameter of the second pipe fitting is matched with the outer diameter of the first pipe fitting; during working, the conical structure is pushed by the internal and external pressure difference of the closed cavity to tightly press the edge sealing gasket to enhance sealing, the condition that the internal pressure of the cavity is smaller than or larger than the external atmospheric pressure can be adapted, current conduction is ensured, the circumferential sealing ring ensures that cooling water flows in a pipeline, and the substrate is made of a non-conductive ceramic material, so that integral sealing can be realized; the problem that an existing sealing device can only be used for single-pressure occasions is effectively solved.

Description

Technical Field

[0001] The invention relates to the field of mechanical manufacturing, in particular to a mechanical sealing device. Background Art

[0002] Induction heating refers to the heating of conductive parts by using the resistance heat generated by the eddy current inside the parts as a heat source when the conductive parts are close to the time-varying magnetic field generated by the alternating current. Some heated parts are chemically active at high temperatures and need to be processed in a sealed cavity by isolating oxygen, carbon dioxide, hydrogen or other related gases, or by filling with specific gases to maintain a certain gas atmosphere. The internal air pressure of the cavity is different in different processing occasions. The pressure may be lower than the atmospheric pressure and reach a certain degree of negative pressure relative to the outside world, or it may be higher than the atmospheric pressure and reach a certain degree of positive pressure relative to the outside world.

[0003] The alternating current required for induction heating needs to be generated by a specific device. Due to its large size, the need for cooling and other factors, this device cannot be placed in a closed cavity in most cases. Therefore, the current generated by it must be introduced into the cavity through a certain conduction device. In addition, the entire heating system needs cooling water for cooling, so water flow is required. During the operation of this device, the sealing of the cavity cannot be destroyed while achieving current conduction and water flow.

[0004] The cavity is generally made of materials that are chemically stable in air or possibly filled with protective gas, and have sufficient strength to withstand the possible pressure difference to maintain structural stability. The cavity is mostly made of metal materials. During the induction heating process, certain measures need to be taken to isolate the metal cavity from being heated. Ceramic materials can be used as isolation materials because of their high strength and non-conductivity.

[0005] The common sealing device which is compressed by a single-sided flange and a sealing ring through a fastener has the problem that it can only be used in one pressure situation: the air pressure in the cavity is greater than the atmospheric pressure or less than the atmospheric pressure. Summary of the invention

[0006] In order to solve the above problems, the present invention discloses a cavity sealing device suitable for induction heating in a closed cavity.

[0007] The specific technical solutions are as follows:

[0008] A cavity sealing device suitable for induction heating in a closed cavity comprises a ceramic substrate, wherein the ceramic substrate and the closed cavity are connected by a metal seal, a first pipe fitting and a second pipe fitting are respectively arranged on the left and right sides of the ceramic substrate, the first pipe fitting is connected to a heating power source, the second pipe fitting is connected to a heating ring, a gap exists between the first pipe fitting, the second pipe fitting and the ceramic substrate to form a cavity, a first sealing ring, a second sealing ring and a third sealing ring are arranged on the first pipe fitting and the second pipe fitting, an elastic structure exists at the end of the first pipe fitting, and the elastic structure is also in contact with the second pipe fitting.

[0009] The first sealing ring is located between the first pipe and the sealed cavity, the second sealing ring is located between the second pipe and the sealed cavity, and the third sealing ring is located at the portion where the first pipe is inserted into the second pipe.

[0010] The first pipe and the second pipe are both provided with fasteners on the upper and lower sides.

[0011] The first pipe member and the second pipe member are split structures, and the first pipe member and the second pipe member are hollow inside and communicate with each other to form a channel.

[0012] The first pipe fitting and the second pipe fitting are both tapered structures as a whole, and both ends of the first pipe fitting and the second pipe fitting are cylinders, and a tapered structure is provided in the middle section.

[0013] The inner diameter of the pipeline of the second pipe fitting and the outer diameter of the pipeline at the corresponding position of the first pipe fitting are matched with each other.

[0014] The advantages of the present invention are:

[0015] 1. The conical structure of the device is pushed by the pressure difference inside and outside the closed cavity to press the edge sealing gasket, which strengthens the seal on the basis of the original seal and further reduces the chance of leakage;

[0016] 2. When the pressure inside the cavity is lower than the external atmospheric pressure, enhanced sealing can be achieved; when the pressure inside the cavity is higher than the external atmospheric pressure, enhanced sealing can also be achieved;

[0017] 3. The end of the conical structure on one side is a structure with a certain elasticity, which ensures that the components in the device always maintain contact during axial movement and ensures the conduction of current;

[0018] 4. The end of the pipe fitting on one side is inserted into the other side, and a circumferential seal is achieved through an annular sealing ring to ensure that the cooling water flows inside the pipe without overflowing;

[0019] 5. The substrate is made of non-conductive ceramic material and can be connected to other parts of the cavity through metal bolts to achieve overall sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an overall schematic cross-sectional view of the sealing device;

[0021] Figure 2 is a schematic diagram of the connection between the first pipe fitting and the second pipe fitting;

[0022] Figure 3 is a structural schematic diagram of a first pipe member;

[0023] Figure 4 Schematic diagram of the device implementation. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] A cavity sealing device suitable for induction heating in a closed cavity comprises a ceramic substrate 1, wherein the ceramic substrate 1 is sealed and connected to the closed cavity, a first pipe 2 and a second pipe 6 are respectively arranged on the left and right sides of the ceramic substrate 1, the first pipe 2 is connected to a heating power source 8, and the second pipe is connected to a heating ring 12, a gap exists between the first pipe 2, the second pipe 6 and the ceramic substrate to form a cavity, a first sealing ring 3, a second sealing ring 5, and a third sealing ring 7 are arranged on the first pipe 2 and the second pipe 6, an elastic structure 14 exists at the end of the first pipe, and the elastic structure 14 is also in contact with the second pipe.

[0026] The first sealing ring 3 is located between the first pipe 2 and the sealed cavity, the second sealing ring 5 is located between the second pipe 6 and the sealed cavity, and the third sealing ring 7 is located at the portion where the first pipe 2 is inserted into the second pipe 6 .

[0027] Fasteners 4 are disposed on the upper and lower parts of the first pipe 2 and the second pipe 6 .

[0028] The first pipe fitting 2 and the second pipe fitting 6 are separate structures, and the first pipe fitting 2 and the second pipe fitting 6 are hollow inside and communicate with each other to form a channel.

[0029] The first pipe fitting 2 and the second pipe fitting 6 are both of a conical structure as a whole, and both ends of the first pipe fitting 2 and the second pipe fitting 6 are cylinders, and a conical structure is provided in the middle section.

[0030] The inner diameter of the pipe of the second pipe fitting 6 and the outer diameter of the pipe at the corresponding position of the first pipe fitting 2 are matched with each other.

[0031] The working principle of the present invention is: the sealing device is installed on the closed cavity 11 with a metal fastener, the first pipe is connected to the induction heating power supply 8, and the second pipe is connected to the heating coil 12. A tubular titanium alloy to-be-heated part 13 is placed in the heating coil 12, as shown in the figure, 9 is a sealing port, 10 is a sealing bolt;

[0032] The fastener 4 may be a bolt or other workpiece that can be spirally rotated. For example, the pre-tightening bolt in the figure provides a certain amount of pre-tightening force, which does not completely compress the sealing ring, and provides operating space for the pressure difference driven reinforced seal;

[0033] Negative pressure state (vacuuming)

[0034] When the sealed chamber is evacuated to 1×10 -3 When the air pressure is lower than the external atmospheric pressure and forms a negative pressure environment, a pressure difference will be generated because the gas pressure in the cavity is atmospheric pressure. Under the action of this pressure difference, the conical structure of the second pipe fitting is pushed to the right, so that the second sealing ring is relaxed, and the inner sealing structure is temporarily invalid. At the same time, the gas in the cavity enters the closed cavity and is pumped away. There is also a pressure difference between the left and right sides of the external conical structure of the first pipe fitting. Driven by this pressure difference, the external conical structure moves to the left and compresses the first sealing ring, thereby achieving enhanced sealing. Through such structural design and pressure difference, the sealing performance of the device is guaranteed under negative pressure.

[0035] A heating experiment was carried out. After heating the temperature to 1000℃ and keeping it warm for 5 minutes, the titanium alloy pipe did not oxidize. This showed that there was no gas leakage during the whole process and the seal was stable, which verified the effectiveness and reliability of the sealing device under negative pressure.

[0036] Positive pressure state (when filled with argon)

[0037] When 1.2×105Pa of argon is filled into the closed chamber as a protective gas, and the pressure inside the chamber is greater than the atmospheric pressure, the pressure directly acts on the conical structure of the second pipe, pushing it to move to the left, pressing the second sealing ring to achieve enhanced sealing. This method of automatically enhancing the seal by using the change in the chamber pressure effectively meets the sealing requirements in a positive pressure environment.

[0038] After the same heating experiment was carried out at 1000℃ for 5 minutes, the titanium alloy pipe did not oxidize, indicating that there was no gas leakage and the seal was stable. In addition, no water leakage occurred during the heating process, which shows that the circumferential sealing ring can move along the axial direction of the pipe and always maintain the water seal between the pipe and the pipe. The circumferential seal is good, which further demonstrates that the device not only has good gas sealing under positive pressure, but also can effectively guarantee the sealing of cooling water, thereby ensuring the normal operation and stability of the entire device during the heating process.

Claims

1. A cavity sealing device suitable for induction heating in a closed cavity, characterized in that: It includes a ceramic substrate, which is sealed and connected to a closed cavity. A first pipe fitting and a second pipe fitting are respectively arranged on the left and right sides of the ceramic substrate. The first pipe fitting is connected to a heating power source, and the second pipe fitting is connected to a heating ring. There is a gap between the first pipe fitting, the second pipe fitting and the ceramic substrate to form a cavity. The first pipe fitting and the second pipe fitting are both provided with a first sealing ring, a second sealing ring and a third sealing ring. An elastic structure exists at the end of the first pipe fitting, and the elastic structure is also in contact with the second pipe fitting.

2. The cavity sealing device suitable for induction heating in a closed cavity according to claim 1, characterized in that: The first sealing ring is located between the first pipe and the sealed cavity, the second sealing ring is located between the second pipe and the sealed cavity, and the third sealing ring is located at the portion where the first pipe is inserted into the second pipe.

3. The cavity sealing device suitable for induction heating in a closed cavity according to claim 1, characterized in that: The first pipe member and the second pipe member are both provided with fasteners on the upper and lower sides.

4. The cavity sealing device suitable for induction heating in a closed cavity according to claim 1, characterized in that: The first pipe member and the second pipe member are split structures, and the first pipe member and the second pipe member are hollow inside and communicate with each other to form a channel.

5. The cavity sealing device suitable for induction heating in a closed cavity according to claim 3, characterized in that: The first pipe fitting and the second pipe fitting are both tapered structures as a whole, and both ends of the first pipe fitting and the second pipe fitting are cylinders, and a tapered structure is provided in the middle section.

6. The cavity sealing device suitable for induction heating in a closed cavity according to claim 4, characterized in that: The inner diameter of the pipeline of the second pipe fitting and the outer diameter of the pipeline at the corresponding position of the first pipe fitting are matched with each other.

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