Vacuum ion nitriding and blackening furnace

Abstract

The utility model discloses a vacuum ion nitriding blackening furnace, including support seat, the top of support seat is installed with the furnace seat, the top of support seat still is installed with the door shape support, the top of door shape support is installed with worm drive motor, the middle part of worm drive motor is screwed with the worm, the bottom fixed mounting of worm has the furnace body, and the middle part fixed mounting of furnace body has a plurality of anode electrode, the top side surface fixed mounting of furnace body has vacuum tube subassembly, the top central fixed mounting of furnace seat has cathode electrode. The utility model is in the nitriding operation process of work piece, and a small amount of nitrogen or hydrogen, nitrogen gas mixture gas gushes from work piece bracket, extension frame surface, directly contacts with the work piece surface of accumulation, cooperates the vacuum air current of upper end, makes the mixed gas flow from below to above, fully contacts with the work piece surface and carries out nitriding processing, avoids the phenomenon that the nitriding treatment of work piece surface accumulation in the furnace is inconsistent.

Description

Technical Field

[0001] This utility model relates to the field of vacuum ion nitriding technology, and in particular to a vacuum ion nitriding blackening furnace. Background Technology

[0002] Ion nitriding is a chemical heat treatment process conducted in a low-vacuum nitrogen-containing atmosphere. The furnace body acts as the anode, and the workpiece as the cathode. A DC voltage of several hundred volts is applied between the anode and cathode, causing a glow discharge that induces nitriding. Ion nitriding is performed in a vacuum chamber. The workpiece is connected to the negative terminal of a high-voltage DC power supply, while the vacuum chamber is connected to the positive terminal. After the vacuum level in the chamber is evacuated to 66.67 Pa, a small amount of nitrogen or a mixture of hydrogen and nitrogen is introduced. When the voltage is adjusted to 400-800V, nitrogen ionizes and decomposes into nitrogen ions, hydrogen ions, and electrons, producing a glow discharge on the workpiece surface. The positive ions are accelerated by the electric field, bombarding the workpiece surface and raising its temperature to the nitriding temperature. Nitrogen ions gain electrons on the steel surface, reducing to nitrogen atoms, which then penetrate the steel surface and diffuse inwards, forming a nitrided layer.

[0003] Ion nitriding furnaces use the workpiece as the cathode and the furnace body as the anode. Nitrogen-containing gas is introduced into the vacuum chamber and a DC voltage is applied. Nitrogen ions bombard the heated workpiece surface under the action of the electric field to complete the nitriding process. By optimizing the process parameters, a nitrided layer can be formed on the workpiece surface. However, the gas inlet structure in most nitriding furnaces is a nozzle structure. The mixed gas entering is extracted by the vacuum unit and has a short residence time, which leads to a decrease in the nitriding quality of the workpiece accumulated in the central area. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a vacuum ion nitriding blackening furnace.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A vacuum ion nitriding blackening furnace includes a support base, a furnace base mounted on top of the support base, a portal frame mounted on top of the support base, a worm gear drive motor mounted on top of the portal frame, a worm screwed into the middle of the worm gear drive motor, a furnace body fixedly mounted at the bottom of the worm, and multiple anode electrodes fixedly mounted in the middle of the furnace body. A vacuum tube assembly is fixedly mounted on the top side of the furnace body. A cathode electrode is fixedly mounted at the top center of the furnace base, and an air inlet assembly is fixedly mounted in the middle of the cathode electrode. A workpiece bracket is screwed into the top of the cathode electrode, and an extension frame is screwed into the top of the workpiece bracket. Both the workpiece bracket and the extension frame are connected to the air inlet assembly. An observation window is provided on the side of the furnace body.

[0006] Preferably, the bottom of the furnace body is provided with a sealing ring that cooperates with the furnace base, and the middle of the furnace body is provided with a heating ring, and the top side of the furnace body is provided with a transverse joint that connects to the vacuum tube assembly.

[0007] Preferably, the vacuum tube assembly includes a negative pressure tube fixedly installed inside the transverse joint, and a vacuum solenoid valve is fixedly installed in the middle of the negative pressure tube. A hollow disc is fixedly installed at the inner end of the negative pressure tube, and the bottom of the disc is provided with annularly distributed suction grooves.

[0008] Preferably, the inner wall of the furnace body is provided with an annular bushing, and the inner wall of the annular bushing is provided with multiple arc-shaped reflective grooves, and the anode electrodes are evenly distributed in the reflective grooves.

[0009] Preferably, the workpiece bracket includes a support tube screwed to the top of the cathode electrode, and the middle part of the support tube is connected to the air intake assembly. The top of the support tube is provided with an internal threaded groove that is screwed to the extension frame. A lower tray is fixedly installed on the top outer side of the support tube, and multiple support plates are provided at the bottom of the lower tray.

[0010] Preferably, the workpiece bracket further includes multiple sector-shaped cavities disposed inside the lower tray, and the ends of the sector-shaped cavities are connected to the support tube, and the upper surface of the sector-shaped cavities is provided with multiple lower ventilation holes.

[0011] Preferably, the extension frame includes an extension tube screwed into an internal threaded groove, and a cap is screwed to the top of the extension tube. An extension tray is installed on the top outer side of the extension tube, and a plurality of annular cavities communicating with the extension tube are provided in the middle of the extension tray. The surface of the extension tray is provided with vent holes penetrating the annular cavities.

[0012] Preferably, the air intake assembly includes a gas distribution solenoid valve connected to the bottom of the furnace base. The inlet of the gas distribution solenoid valve is connected to a mixing tank via a pipe. The inlet of the mixing tank is connected to a gas delivery solenoid valve via a pipe, and a gas storage tank is connected to the inlet of the gas delivery solenoid valve.

[0013] The beneficial effects of this utility model are as follows: 1. This utility model proposes a vacuum ion nitriding blackening furnace, which is equipped with a furnace body connected by a worm gear drive motor and a worm, allowing the furnace body to be lifted away from the furnace base. A cathode electrode, a workpiece support, and an extension frame are sequentially installed in the middle of the furnace base. The workpiece is placed on the workpiece support and extension frame and electrically connected to the cathode electrode. After the furnace body is lowered and sealed with the furnace base, a vacuum pump connected to a vacuum tube assembly can be used to extract the vacuum inside the furnace body. An air inlet assembly is also connected to the bottom of the workpiece support and extension frame. During the nitriding process, a small amount of nitrogen or a mixture of hydrogen and nitrogen gas emerges from the surface of the workpiece support and extension frame and directly contacts the surface of the accumulated workpiece. Combined with the vacuum airflow at the top, the mixed gas flows from bottom to top, fully contacting the workpiece surface for nitriding processing, thus avoiding inconsistent nitriding treatment of the surface of the accumulated workpiece inside the furnace.

[0014] 2. The present invention proposes a vacuum ion nitriding blackening furnace, wherein the extension frame is screwed onto the workpiece support to form an electrical connection structure with the cathode electrode. The gas introduced into the furnace body by the gas inlet assembly enters the extension frame through the support pipe for diffusion. The number of extension frame layers can be increased or decreased according to the size of the workpiece to obtain the maximum utilization of the furnace space and improve the nitriding efficiency of the workpiece. In addition, part of the gas entering the furnace body is dissipated through the fan-shaped cavity and the lower vent hole. Under vacuum conditions, it moves upward from the lower surface of the workpiece and contacts the surface of the accumulated workpiece layer by layer, thereby improving the nitriding quality of the surface of the accumulated workpiece.

[0015] 3. The present invention proposes a vacuum ion nitriding blackening furnace in which workpieces are stacked on an extension tray. Most of the gas entering the furnace body enters the annular cavity through the extension pipe and diffuses simultaneously on the upper and lower surfaces of the extension tray through the exhaust hole penetrating the annular cavity, thereby increasing the ionization rate. Under vacuum conditions, the gas fully contacts the surface of the stacked workpieces, thereby improving the nitriding processing quality of the surface of the internally stacked workpieces. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a vacuum ion nitriding blackening furnace proposed in this utility model; Figure 2 This is a schematic diagram of the furnace body lifting structure of a vacuum ion nitriding blackening furnace proposed in this utility model. Figure 3 This is a schematic diagram of the internal structure of a vacuum ion nitriding blackening furnace proposed in this utility model. Figure 4 This is a schematic diagram of the air inlet assembly structure of a vacuum ion nitriding blackening furnace proposed in this utility model; Figure 5 This is a schematic diagram of the workpiece support distribution structure of a vacuum ion nitriding blackening furnace proposed in this utility model; Figure 6 This is a cross-sectional view of a workpiece support structure for a vacuum ion nitriding blackening furnace proposed in this utility model. Figure 7 This is a cross-sectional view of the extension frame of a vacuum ion nitriding blackening furnace proposed in this utility model.

[0017] In the diagram: 1 Support base, 2 Furnace base, 3 Portal bracket, 4 Furnace body, 41 Sealing ring, 42 Horizontal joint, 43 Heating ring, 5 Worm gear, 6 Worm gear drive motor, 7 Vacuum tube assembly, 71 Disc, 72 Negative pressure pipe, 73 Vacuum solenoid valve, 74 Evacuation slot, 8 Inlet assembly, 81 Gas distribution solenoid valve, 82 Mixing tank, 83 Gas delivery solenoid valve, 84 Gas storage tank, 9 Observation window, 10 Workpiece bracket, 101 Support tube, 102 Lower tray, 103 Internal threaded groove, 104 Sector cavity, 105 Lower vent hole, 11 Extension frame, 111 Extension tube, 112 Extension tray, 113 End cap, 114 Annular cavity, 115 Exhaust hole, 12 Annular bushing, 13 Anode electrode, 14 Reflection groove, 15 Cathode electrode. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] Reference Figures 1-3 A vacuum ion nitriding blackening furnace includes a support base 1, a furnace base 2 mounted on the top of the support base 1, a portal frame 3 mounted on the top of the support base 1, a worm gear drive motor 6 mounted on the top of the portal frame 3, a worm 5 screwed into the middle of the worm gear drive motor 6, a furnace body 4 fixedly mounted at the bottom of the worm 5, and multiple anode electrodes 13 fixedly mounted in the middle of the furnace body 4. A vacuum tube assembly 7 is fixedly mounted on the top side of the furnace body 4. A cathode electrode 15 is fixedly mounted in the center of the top of the furnace base 2, and an air inlet assembly 8 is fixedly mounted in the middle of the cathode electrode 15. A workpiece bracket 10 is screwed into the top of the cathode electrode 15, and an extension bracket 11 is screwed into the top of the workpiece bracket 10. Both the workpiece bracket 10 and the extension bracket 11 are connected to the air inlet assembly 8. An observation window 9 is provided on the side of the furnace body 4.

[0020] In this invention, a furnace body 4 is provided, which is connected to a worm gear drive motor 6 and a worm 5, allowing the furnace body 4 to be lifted away from the furnace base 2. A cathode electrode 15, a workpiece bracket 10, and an extension frame 11 are sequentially installed in the middle of the furnace base 2. The workpiece is placed on the workpiece bracket 10 and the extension frame 11 and electrically connected to the cathode electrode 15. After the furnace body 4 is lowered and sealed with the furnace base 2, the vacuum inside the furnace body 4 can be extracted by a vacuum pump connected to the vacuum tube assembly 7. An air inlet assembly 8 is also connected to the bottom of the workpiece bracket 10 and the extension frame 11. During the nitriding process, a small amount of nitrogen or a mixture of hydrogen and nitrogen gas flows out from the surface of the workpiece bracket 10 and the extension frame 11 and directly contacts the surface of the accumulated workpiece. Combined with the vacuum airflow at the top, the mixed gas flows from bottom to top, fully contacting the workpiece surface for nitriding processing, thus avoiding inconsistent nitriding treatment of the surface of the accumulated workpiece inside the furnace.

[0021] Reference Figure 3 The furnace body 4 has a sealing ring 41 at the bottom that matches the furnace base 2, and a heating ring 43 in the middle of the furnace body 4. The top side of the furnace body 4 has a transverse connector 42 that connects to the vacuum tube assembly 7. In this utility model, after the furnace body 4 and the furnace base 2 are sealed together, the temperature is raised by the heating ring 43 located inside the furnace body 4 to control the temperature of the nitriding operation.

[0022] Reference Figure 3 The vacuum tube assembly 7 includes a negative pressure tube 72 fixedly installed inside the transverse joint 42, and a vacuum solenoid valve 73 fixedly installed in the middle of the negative pressure tube 72. A hollow disc 71 is fixedly installed at the inner end of the negative pressure tube 72, and the bottom of the disc 71 is provided with annularly arrayed suction grooves 74. In this invention, the outlet end of the vacuum solenoid valve 73 is connected to a vacuum unit to maintain an internal vacuum environment when the furnace body 4 is working. When extracting gas from inside the furnace body 4, the negative pressure suction is dispersed from multiple suction grooves 74 distributed at the top of the furnace body 4 to increase the diffusion area of ​​hydrogen, nitrogen and other gases entering from the bottom, thereby improving the quality of nitriding on the surface of the workpiece.

[0023] Reference Figure 3 The inner wall of the furnace body 4 is provided with an annular bushing 12, and the inner wall of the annular bushing 12 is provided with multiple arc-shaped reflective grooves 14. The anode electrodes 13 are evenly distributed in the reflective grooves 14. In this utility model, the heat transfer efficiency inside the furnace body 4 is increased by the annular bushing 12 and the reflective arcs 14 on its surface. The anode electrodes 13 are installed in the concave part of the reflective grooves 14. When the reflective grooves 14 reflect heat, they accelerate the movement speed of ions, thereby improving the nitriding efficiency of the workpiece surface.

[0024] Reference Figure 4The air intake assembly 8 includes a gas distribution solenoid valve 81 connected to the bottom of the furnace base 2. The inlet of the gas distribution solenoid valve 81 is connected to a mixing tank 82 via a pipe. The inlet of the mixing tank 82 is connected to a gas delivery solenoid valve 83 via a pipe, and a gas storage tank 84 is connected to the inlet of the gas delivery solenoid valve 83. In this invention, a single gas enters the mixing tank 82 in proportion for mixing. Then, the gas is connected to the furnace body 4 via the gas distribution solenoid valve 81. The vacuum environment inside the furnace body 4 is used to quickly draw gas from the mixing tank 82. The temporary storage in the mixing tank 82 improves the control effect of the gas delivery in the furnace and further enhances the quality of the nitriding treatment of the workpiece.

[0025] Reference Figures 5-6 The workpiece support 10 includes a support tube 101 screwed to the top of the cathode electrode 15, and the middle part of the support tube 101 is connected to the air inlet assembly 8. The top of the support tube 101 is provided with an internal threaded groove 103 that is screwed to the extension frame 11. A lower tray 102 is fixedly installed on the top of the outer side of the support tube 101, and multiple support plates are provided at the bottom of the lower tray 102. In this utility model, the extension frame 11 is screwed onto the workpiece support 10 to form an electrical connection structure with the cathode electrode 15. The gas introduced into the furnace body 4 by the air inlet assembly 8 enters the interior of the extension frame 11 through the support tube 101 for diffusion. The number of layers of the extension frame 11 can be increased or decreased according to the size of the workpiece to obtain the maximum utilization rate of the furnace space and improve the efficiency of the nitriding process of the workpiece.

[0026] Reference Figure 6 The workpiece bracket 10 also includes multiple sector-shaped cavities 104 disposed inside the lower tray 102, and the ends of the sector-shaped cavities 104 are connected to the support tube 101. Multiple lower vent holes 105 are provided on the upper surface of the sector-shaped cavities 104. In this utility model, the workpieces to be processed are piled up on the surface of the workpiece bracket 10. The gas entering the furnace body 4 is partially dissipated through the sector-shaped cavities 104 and the lower vent holes 105. Under vacuum conditions, the gas moves upward from the lower surface of the workpiece and contacts the surface of the piled workpieces layer by layer, thereby improving the nitriding processing quality of the surface of the internally piled workpieces.

[0027] Reference Figure 7The extension frame 11 includes an extension tube 111 screwed into an internal threaded groove 103, and a cap 113 screwed onto the top of the extension tube 111. An extension tray 112 is installed on the outer top of the extension tube 111, and a plurality of annular cavities 114 communicating with the extension tube 111 are provided in the middle of the extension tray 112. An exhaust hole 115 penetrating the annular cavity 114 is provided on the surface of the extension tray 112. In this utility model, the workpieces are stacked on the extension tray 112. Most of the gas entering the furnace body 4 enters the annular cavity 114 through the extension tube 111, and diffuses simultaneously on the upper and lower surfaces of the extension tray 112 through the exhaust hole 115 penetrating the annular cavity 114, increasing the ionization rate. Under vacuum conditions, it fully contacts the surface of the stacked workpieces, thereby improving the nitriding processing quality of the surface of the internally stacked workpieces.

[0028] Working principle: The workpiece is placed on the workpiece bracket 10 and the extension bracket 11 and electrically connected to the cathode electrode 15. After the furnace body 4 is lowered and sealed with the furnace base 2, the vacuum inside the furnace body 4 can be drawn by the vacuum pump connected to the vacuum tube assembly 7. At the bottom of the workpiece bracket 10 and the extension bracket 11, there is also a venting air inlet assembly 8. During the nitriding operation, a small amount of nitrogen or a mixture of hydrogen and nitrogen gas flows out from the surface of the workpiece bracket 10 and the extension bracket 11 and directly contacts the surface of the accumulated workpiece. With the vacuum airflow at the top, the mixed gas flows from bottom to top and fully contacts the workpiece surface for nitriding.

[0029] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A vacuum ion nitriding blackening furnace, comprising a support base (1), a furnace base (2) mounted on the top of the support base (1), a portal frame (3) also mounted on the top of the support base (1), a worm gear drive motor (6) mounted on the top of the portal frame (3), and a worm (5) screwed into the middle of the worm gear drive motor (6), characterized in that, The bottom of the worm gear (5) is fixedly installed with a furnace body (4), and a plurality of anode electrodes (13) are fixedly installed in the middle of the furnace body (4). A vacuum tube assembly (7) is fixedly installed on the top side of the furnace body (4). A cathode electrode (15) is fixedly installed in the center of the top of the furnace base (2), and an air inlet assembly (8) is fixedly installed in the middle of the cathode electrode (15). A workpiece bracket (10) is screwed to the top of the cathode electrode (15), and an extension bracket (11) is screwed to the top of the workpiece bracket (10). Both the workpiece bracket (10) and the extension bracket (11) are connected to the air inlet assembly (8). An observation window (9) is provided on the side of the furnace body (4).

2. The vacuum ion nitriding blackening furnace according to claim 1, characterized in that, The bottom of the furnace body (4) is provided with a sealing ring (41) that cooperates with the furnace base (2), and a heating ring (43) is provided in the middle of the furnace body (4). A transverse connector (42) that connects to the vacuum tube assembly (7) is provided on one side of the top of the furnace body (4).

3. A vacuum ion nitriding blackening furnace according to claim 2, characterized in that, The vacuum tube assembly (7) includes a negative pressure tube (72) fixedly installed inside the transverse joint (42), and a vacuum solenoid valve (73) is fixedly installed in the middle of the negative pressure tube (72). A hollow disc (71) is fixedly installed at the inner end of the negative pressure tube (72), and a ring array of suction grooves (74) is provided at the bottom of the disc (71).

4. The vacuum ion nitriding blackening furnace according to claim 1, characterized in that, The inner wall of the furnace body (4) is provided with an annular bushing (12), and the inner wall of the annular bushing (12) is provided with multiple arc-shaped reflective grooves (14), and the anode electrodes (13) are evenly distributed in the reflective grooves (14).

5. A vacuum ion nitriding blackening furnace according to claim 1, characterized in that, The workpiece bracket (10) includes a support tube (101) screwed to the top of the cathode electrode (15), and the middle part of the support tube (101) is connected to the air intake assembly (8). The top of the support tube (101) is provided with an internal thread groove (103) that is screwed to the extension frame (11). The outer top of the support tube (101) is fixedly installed with a lower tray (102), and the bottom of the lower tray (102) is provided with multiple support plates.

6. A vacuum ion nitriding blackening furnace according to claim 5, characterized in that, The workpiece bracket (10) also includes a plurality of sector-shaped cavities (104) disposed inside the lower tray (102), and the ends of the sector-shaped cavities (104) are connected to the support tube (101). The upper surface of the sector-shaped cavities (104) is provided with a plurality of lower ventilation holes (105).

7. A vacuum ion nitriding blackening furnace according to claim 5, characterized in that, The extension frame (11) includes an extension tube (111) screwed into an internal threaded groove (103), and a cap (113) is screwed to the top of the extension tube (111). An extension tray (112) is installed on the outer top of the extension tube (111), and a plurality of annular cavities (114) communicating with the extension tube (111) are provided in the middle of the extension tray (112). An exhaust hole (115) penetrating the annular cavity (114) is provided on the surface of the extension tray (112).

8. A vacuum ion nitriding blackening furnace according to claim 1, characterized in that, The air intake assembly (8) includes a gas distribution solenoid valve (81) connected to the bottom of the furnace base (2). The inlet of the gas distribution solenoid valve (81) is connected to a mixing tank (82) via a pipe. The inlet end of the mixing tank (82) is connected to a gas delivery solenoid valve (83) via a pipe. A gas storage tank (84) is connected to the inlet of the gas delivery solenoid valve (83).

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