Muffle air duct connecting structure of ultra-deep well type nitriding furnace

Abstract

The utility model belongs to the technical field of nitriding furnaces, and particularly relates to a muffle air duct connecting structure of an ultra-deep well type nitriding furnace. The connecting structure comprises a muffle and an air guide cylinder, the air guide cylinder is hung in the muffle, a workpiece fixing position is installed in the air guide cylinder, the thickness of the lower portion, where the air guide cylinder is hung, of the muffle is gradually reduced from top to bottom, and the thickness of the lower portion, where the workpiece fixing position is installed, of the air guide cylinder is gradually reduced from top to bottom. The connecting structure solves the problems that an existing muffle and an existing ventilating duct are large in dead weight and high in cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of nitriding furnaces, in particular to a muffle air guide tube connection structure of an ultra-deep well nitriding furnace. Background Art

[0002] The nitriding furnace is a device used to place the workpiece to be processed in a vacuum container and perform nitriding treatment under glow discharge conditions. The workpiece is placed in the furnace as the cathode, the furnace body as the anode, and then a small amount of ammonia, nitrogen or nitrogen-argon mixed gas is passed in. Then a certain voltage is applied between the two electrodes to ionize the nitrogen. After the nitrogen is ionized, it impacts the workpiece at a high speed. The kinetic energy of the ions is converted into heat energy to heat the workpiece to the nitriding temperature. A part of the nitrogen that bombards the surface captures electrons and directly penetrates into the surface of the workpiece, forming Fe with a high nitrogen content in a vaporized state on the surface of the workpiece, and continuously diffuses into the interior of the workpiece, thereby achieving the purpose of nitriding.

[0003] A muffle is installed in the nitriding furnace. The muffle refers to a sealed box structure set up in the furnace to achieve sealing and controllable atmosphere. It is generally made of high-temperature resistant stainless steel. An air duct is installed inside the muffle for ventilation. The existing muffle and air duct are generally between 5-6 meters long. In order to ensure strength, the wall thickness of the muffle and air duct is uniform. If the length is increased to 10 meters, in order to ensure high strength requirements, more materials need to be used, resulting in high production costs and heavy weight of the muffle and air duct. Utility Model Content

[0004] The utility model provides a muffle air guide tube connection structure of an ultra-deep well nitriding furnace, which solves the above problems.

[0005] The technical solution of the utility model is achieved in this way:

[0006] The muffle and air guide tube connection structure of the ultra-deep well nitriding furnace includes a muffle and an air guide tube, the air guide tube is suspended inside the muffle, a workpiece fixing position is installed inside the air guide tube, the lower thickness of the muffle where the air guide tube is suspended gradually decreases from top to bottom, and the lower thickness of the air guide tube where the workpiece fixing position is installed gradually decreases from top to bottom.

[0007] Through the above technical scheme, the thickness change of the muffle and the air guide tube can not only ensure their own strength, but also save costs. The positions where the thickness of the muffle and the air guide tube changes are respectively located at the hanging position and below the workpiece fixing position, which can not only meet the strength requirements of the air guide tube and the workpiece fixing position, but also reduce the material manufacturing cost of the muffle and the air guide tube by reducing the thickness.

[0008] Optionally, the position where the muffle suspends the air guide tube is on the same horizontal line as the position where the air guide tube is installed on the workpiece fixing position.

[0009] Through the above technical solution, the heights of the two positions are consistent, which is conducive to concentrating the forces of the muffle and the air guide tube on the upper part, and increasing the strength and reducing the cost by increasing the thickness of the upper part and reducing the thickness of the lower part.

[0010] Optionally, the lower end side wall of the muffle and the lower end side wall of the air guide tube are wavy.

[0011] Through the above technical solution, the wavy design of the muffle and the air guide tube can offset the influence of thermal expansion and contraction, improve the temperature tolerance of the muffle and the air guide tube, and increase the service life.

[0012] Optionally, the muffle and the air guide tube are both in a straight cylindrical shape.

[0013] Through the above technical solution, the straight-cylindrical design of the muffle and the air guide tube can reduce the wind resistance during ventilation and improve ventilation efficiency, so that the workpiece maintains uniformity during the nitriding process and improves the nitriding efficiency.

[0014] Optionally, there is a gap between the outer wall of the air guide tube and the inner wall of the muffle, there is a gap between the top of the air guide tube and the top of the muffle, and there is a gap between the bottom of the air guide tube and the bottom of the muffle.

[0015] Through the above technical solution, there is a gap between the air guide tube and the muffle, which makes it convenient to install and disassemble the air guide tube from the muffle, and also helps to reserve sufficient space for internal ventilation of the muffle.

[0016] After adopting the above technical solution, the beneficial effects of the utility model are:

[0017] In the utility model, an air guide tube is suspended inside the muffle, and a workpiece fixing position is installed inside the air guide tube. In order to reduce the dead weight of the muffle and the air guide tube and reduce the manufacturing cost, the thickness of the muffle is reduced below the hanging position of the air guide tube, and the thickness of the air guide tube is reduced below the workpiece fixing position, so that the strength requirements of the muffle and the air guide tube can be guaranteed, and the dead weight of the muffle and the air guide tube can be reduced by reducing the wall thickness, thereby reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 12. It is a front view of the muffle and air guide tube connection structure in the embodiment;

[0020] Figure 2 3. It is a top view of the muffle and air guide tube connection structure in the embodiment.

[0021] Explanation of the accompanying reference numerals: 1. muffle; 2. air guide tube; 3. support plate; 4. clamping plate; 5. limit table; 6. buffer plate; 7. inclined plane; 8. workpiece fixing position. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The embodiment of the present application discloses a muffle air guide tube connection structure of an ultra-deep well nitriding furnace.

[0024] Example

[0025] according to Figure 1 to Figure 2 As shown, the muffle air guide tube connection structure of the ultra-deep pit nitriding furnace includes a muffle 1 and an air guide tube 2, the air guide tube 2 is suspended inside the muffle 1, and a workpiece fixing position 8 is installed inside the air guide tube 2. The thickness of the lower part of the muffle 1 where the air guide tube 2 is suspended gradually decreases from top to bottom, and the thickness of the lower part of the air guide tube 2 where the workpiece fixing position 8 is installed gradually decreases from top to bottom. The position where the muffle 1 suspends the air guide tube 2 and the position where the workpiece fixing position 8 is installed on the air guide tube 2 are on the same horizontal line.

[0026] The lower end side wall of the muffle 1 and the lower end side wall of the air guide tube 2 are wavy. The muffle 1 and the air guide tube 2 are both straight tube-shaped. There is a gap between the outer side wall of the air guide tube 2 and the inner side wall of the muffle 1, there is a gap between the top of the air guide tube 2 and the top of the muffle 1, and there is a gap between the bottom of the air guide tube 2 and the bottom of the muffle 1.

[0027] The inner wall of the muffle 1 is provided with a plurality of support plates 3 at intervals along the annular direction, and the outer wall of the air guide tube 2 is provided with a plurality of clamping plates 4 corresponding to the support plates 3 at intervals along the annular direction, and the bottom of the clamping plates 4 is in contact with the top of the support plate 3. A limiting platform 5 is provided on the top of the support plate 3, and a buffer plate 6 is provided on the side of the clamping plate 4 away from the air guide tube 2, and the buffer plate 6 faces the limiting platform 5, and the height of the buffer plate 6 is greater than the height of the limiting platform 5. A slope 7 inclined toward the air guide tube 2 is provided on the side of the clamping plate 4 away from the air guide tube 2. The cooperation between the limiting platform 5 and the buffer plate 6 can improve the stability and safety of the contact between the clamping plate 4 and the support plate 3, reduce friction, and improve the service life of the clamping plate 4 and the support plate 3. The inclined surface 7 provided on the clamping plate 4 can reduce the side volume of the air guide tube 2, reduce wind resistance, and improve the ventilation efficiency of the air guide tube 2.

[0028] The thickness variation of the muffle 1 and the air guide tube 2 can ensure their own strength and save costs. The positions where the thickness of the muffle 1 and the air guide tube 2 varies are respectively located at the hanging position and below the workpiece fixing position 8, which can meet the strength requirements of the air guide tube 2 and the workpiece fixing position 8, and can reduce the material manufacturing cost of the muffle 1 and the air guide tube 2 by reducing the thickness. The height of the hanging position of the air guide tube 2 is consistent with the position of the workpiece fixing position 8, which is conducive to concentrating the forces of the muffle 1 and the air guide tube 2 on the upper part, increasing the thickness of the upper part and reducing the thickness of the lower part to increase the strength and reduce the cost.

[0029] The wavy design of the muffle 1 and the air guide tube 2 can offset the influence of thermal expansion and contraction, improve the temperature tolerance of the muffle 1 and the air guide tube 2, and increase the service life. The straight-tube design of the muffle 1 and the air guide tube 2 can reduce the wind resistance during ventilation, improve the ventilation efficiency, keep the workpiece uniform during the nitriding process, and improve the nitriding efficiency. There is a gap between the air guide tube 2 and the muffle 1, so that the air guide tube 2 is convenient to install and disassemble with the muffle 1, and it is also conducive to reserving sufficient space for internal ventilation of the muffle 1.

[0030] In the description of the present utility model, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A muffle air guide tube connection structure of an ultra-deep pit nitriding furnace, comprising a muffle and an air guide tube, wherein the air guide tube is suspended inside the muffle, and a workpiece fixing position is installed inside the air guide tube, characterized in that: The thickness of the lower part of the muffle where the air guide tube is suspended gradually decreases from top to bottom, and the thickness of the lower part of the air guide tube where the workpiece is fixed gradually decreases from top to bottom.

2. The muffle air guide tube connection structure of the ultra-deep pit nitriding furnace according to claim 1 is characterized in that: The position where the muffle suspends the air guide tube is on the same horizontal line as the position where the air guide tube is installed on the workpiece fixing position.

3. The muffle air guide tube connection structure of the ultra-deep pit nitriding furnace according to claim 1 is characterized in that: The lower end side wall of the muffle and the lower end side wall of the air guide tube are wavy.

4. The muffle air guide tube connection structure of the ultra-deep pit nitriding furnace according to claim 1 is characterized in that: The muffle and the air guide tube are both in a straight cylindrical shape.

5. The muffle air guide tube connection structure of the ultra-deep pit nitriding furnace according to claim 1 is characterized in that: There is a gap between the outer wall of the air guide cylinder and the inner wall of the muffle, there is a gap between the top of the air guide cylinder and the top of the muffle, and there is a gap between the bottom of the air guide cylinder and the bottom of the muffle.

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