Vacuum apparatus for debinding and sintering

Abstract

The utility model discloses a kind of vacuum devices of defatting sintering, belong to hard alloy production technical field.The vacuum device of defatting sintering includes: heat treatment furnace, first air extraction path, second air extraction path and air extraction pump assembly, wherein, heat treatment furnace includes furnace shell and inner furnace, inner furnace is located in furnace shell, and with furnace shell between having heating gap.By first air extraction path and second air extraction path can respectively to the inside of inner furnace and the heating gap in furnace shell are extracted vacuum treatment, so that the double-layer structure of heat treatment furnace can be in double-layer vacuum state.Can avoid gas in heating gap permeate to inner furnace, can maintain the vacuum degree in inner furnace, also can inhibit gas in inner furnace permeate to heating gap, reduce the risk of process pollution, to enhance the vacuum sealing reliability of defatting sintering vacuum device.

Description

Technical Field

[0001] This utility model relates to the field of cemented carbide production technology, and in particular to a degreasing and sintering vacuum device. Background Technology

[0002] A heat treatment furnace is a device used to heat, hold, and cool metallic materials to improve their properties or transform their microstructure. Heat treatment furnaces can include vacuum sintering furnaces, vacuum degreasing sintering furnaces, etc. A vacuum degreasing sintering furnace refers to a heat treatment furnace that performs protective degreasing and sintering of heated items in a vacuum environment. For example, a vacuum degreasing sintering furnace can be used for the degreasing and sintering process of pressed metal powder bodies.

[0003] Vacuum degreasing sintering furnaces typically include a furnace shell, an inner furnace, and heating elements. The inner furnace is located inside the furnace shell, and the heating elements are usually located in the heating gap between the furnace shell and the inner furnace. The chamber of the inner furnace can be used to place the material to be heated, and the heating elements are used to heat the material located in the chamber of the inner furnace.

[0004] Currently, when using a vacuum degreasing sintering furnace to heat materials, the poor reliability of the vacuum seal in the furnace leads to a risk of process contamination during processing.

[0005] Furthermore, in the process of vacuum degreasing and sintering furnace, although both the degreasing and sintering steps require a vacuum environment, there are significant differences between the two in terms of vacuum requirements, heating conditions, and process objectives. The core technical challenge lies in how to achieve the following through optimized vacuum pipeline system design: precise step-by-step control to meet the vacuum, pumping speed, and gas load requirements of different stages; efficient switching and isolation to avoid cross-contamination and reduce transition time; and system compatibility and reliability to balance the high-throughput exhaust in the degreasing stage and the high vacuum stability in the sintering stage. Utility Model Content

[0006] This utility model embodiment provides a debinding and sintering vacuum device, the technical solution of which is as follows:

[0007] According to one aspect of the present invention, a degreasing sintering vacuum device is provided, the degreasing sintering vacuum device comprising:

[0008] Heat treatment furnace, first exhaust path, second exhaust path and exhaust pump assembly;

[0009] The heat treatment furnace includes a furnace shell and an inner furnace. The inner furnace is located inside the furnace shell and has a heating gap between it and the furnace shell. The inner furnace is capable of permeating gas.

[0010] The air inlet of the first air extraction path is connected to the heating gap, and the air outlet of the first air extraction path is connected to the air pump assembly.

[0011] The inlet of the second exhaust path is connected to the interior of the inner furnace, and the outlet of the second exhaust path is connected to the exhaust pump assembly.

[0012] The air pump assembly includes a Roots pump and a rotary vane pump connected in series. One end of the Roots pump is connected to the outlet of the first air extraction path and the outlet of the second air extraction path, and the other end of the Roots pump is connected to the rotary vane pump. The rotary vane pump has a gas ballast valve.

[0013] Optionally, the air inlet of the first exhaust path is connected to the heating gap from the top of the heat treatment furnace, and the air inlet of the second exhaust path is connected to the interior of the inner furnace from the bottom of the heat treatment furnace.

[0014] The inner furnace includes a cylindrical box made of graphite and two end caps made of graphite, which are located at both ends of the box and are movably connected to the box.

[0015] Optionally, the first exhaust path includes a first pipeline and a first valve. The inlet of the first pipeline is located between the furnace shell and the inner furnace, the outlet of the first pipeline is connected to the exhaust pump assembly, and the first valve is installed on the first pipeline.

[0016] The second exhaust path includes a second pipeline and a second valve. The inlet of the second pipeline is located in the inner furnace, and the outlet of the second pipeline is connected to the exhaust pump assembly. The second valve is installed on the second pipeline.

[0017] One end of the Roots pump is connected to the air outlet of the first pipeline and the air outlet of the second pipeline.

[0018] Optionally, the degreasing and sintering vacuum device further includes: a first connecting gas path and a first regulating gas path connected in parallel;

[0019] The air inlet of the first connecting air passage and the air inlet of the first regulating air passage are both connected to the air outlet of the first pipeline and the air outlet of the second pipeline, and the air outlet of the first connecting air passage and the air outlet of the first regulating air passage are both connected to the Roots pump.

[0020] The first regulating gas path is used to regulate the gas flow rate of the first pipeline and the second pipeline.

[0021] Optionally, the first connecting air path includes a third pipeline and a third valve. The air inlet of the third pipeline is connected to the air outlet of the first pipeline and the air outlet of the second pipeline. The air outlet of the third pipeline is connected to the Roots pump. The third valve is installed on the third pipeline.

[0022] The first regulating air path includes a fourth pipeline, a fourth valve, and a proportional valve. The air inlet of the fourth pipeline is connected to the air outlet of the first pipeline and the air outlet of the second pipeline. The air outlet of the fourth pipeline is connected to the Roots pump. The fourth valve and the proportional valve are installed in parallel on the fourth pipeline.

[0023] Optionally, the degreasing and sintering vacuum device further includes: a gas storage tank, a gas filling line, a second connecting gas line and a second regulating gas line connected in parallel;

[0024] The gas storage tank is used to store inert gas;

[0025] The inlet end of the second connecting gas path and the inlet end of the second regulating gas path are both connected to the gas storage tank. The outlet end of the second connecting gas path and the outlet end of the second regulating gas path are both connected to the inner furnace through the charging gas path. The second regulating gas path is used to regulate the gas flow rate of the charging gas path.

[0026] Optionally, the gas filling circuit includes a fifth pipeline and a fifth valve, the outlet of the fifth pipeline is connected to the inner furnace, and the fifth valve is installed on the fifth pipeline;

[0027] The second connecting gas path includes a sixth pipeline and a sixth valve. The inlet of the sixth pipeline is connected to the gas storage tank, the outlet of the sixth pipeline is connected to the inlet of the fifth pipeline, and the sixth valve is installed on the sixth pipeline.

[0028] The second regulating gas path includes a seventh pipeline and a mass flow controller. The inlet of the seventh pipeline is connected to the gas storage tank, and the outlet of the seventh pipeline is connected to the inlet of the fifth pipeline. The mass flow controller is installed on the seventh pipeline.

[0029] Optionally, the degreasing and sintering vacuum device further includes: an air inlet pipe, a seventh valve, a wax collection cylinder, an air outlet pipe, an eighth valve, and a mold temperature controller;

[0030] The two ends of the air inlet pipe are respectively connected to the inner furnace and the wax collection cylinder, and the seventh valve is installed on the air inlet pipe;

[0031] The two ends of the air outlet pipe are respectively connected to the wax collection cylinder and the rotary vane pump, and the eighth valve is installed on the air outlet pipe;

[0032] The mold temperature controller is connected to the wax collection cylinder.

[0033] Optionally, the heat treatment furnace further includes a heating element, and the degreasing and sintering vacuum device further includes a cooling fan, cooling fins, and cooling water channels;

[0034] The heating element is located in the heating gap;

[0035] The cooling fan is located inside the furnace shell and at one end of the inner furnace;

[0036] The heat dissipation fins are located between the heat dissipation fan and the inner furnace;

[0037] The cooling water path is connected to the heat dissipation fins.

[0038] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following:

[0039] A degreasing and sintering vacuum device is provided, comprising a heat treatment furnace, a first evacuation path, a second evacuation path, an evacuation pump assembly, and a pressure detection assembly. The heat treatment furnace includes a furnace shell and an inner furnace, with the inner furnace located inside the furnace shell and having a heating gap between them. The inlet end of the first evacuation path can communicate with the heating gap, and the inlet end of the second evacuation path can communicate with the interior of the inner furnace. The outlet ends of both the first and second evacuation paths are connected to the evacuation pump assembly. Thus, the first and second evacuation paths can respectively evacuate the interior of the inner furnace and the heating gap within the furnace shell, allowing the double-layer structure of the heat treatment furnace to maintain a double-layer vacuum state. This prevents gas from the heating gap from permeating into the inner furnace, maintains the vacuum level in the inner furnace, and suppresses gas permeation from the inner furnace into the heating gap, reducing the risk of process contamination and thus enhancing the vacuum sealing reliability of the degreasing and sintering vacuum device.

[0040] Furthermore, if the material releases combustible gases during sintering, the second evacuation path can promptly remove these gases. This prevents the accumulation of combustible gases in the heating gaps, reducing the risk of explosion in the heat treatment furnace and improving the safety of the degreasing and sintering vacuum device. In addition, the double-layer vacuum creates a double thermal insulation barrier. Specifically, by evacuating the interior of the inner furnace, gas convection and heat conduction within the deheating chamber are reduced, minimizing heat loss from the material. Furthermore, by evacuating the heating gaps, heat radiation and conduction to the outside of the furnace shell are further blocked, improving the temperature uniformity within the heat treatment furnace.

[0041] Furthermore, by combining a Roots pump and a rotary vane pump into a vacuum pump unit, with the rotary vane pump acting as a pre-pump and the Roots pump as a booster pump, the heat treatment furnace is first evacuated from atmospheric pressure to the starting pressure of the Roots pump via the rotary vane pump, and then the Roots pump rapidly increases the vacuum level to the target vacuum level, thus improving pumping efficiency. The rotary vane pump can be equipped with a gas ballast valve, which can improve the efficiency of the rotary vane pump in handling condensable gases (such as water vapor, solvent vapor, etc.) and prevent condensable gases from condensing and contaminating the pump oil in the rotary vane pump.

[0042] In addition, the inlet end of the first evacuation path is connected to the heating gap from the top of the heat treatment furnace, and the inlet end of the second evacuation path is connected to the interior of the inner furnace from the bottom of the heat treatment furnace. This allows for vacuuming from the top of the heating gap to efficiently capture the heated gas, conforming to the natural convection law and reducing evacuation energy consumption. Vacuuming from the bottom of the inner furnace can stably extract gases or particles with higher density (such as unvolatile deposits).

[0043] Furthermore, by separately configuring a degreasing component for vacuum degreasing, which is independent of the vacuum lines (first and second pumping lines) used in the sintering step, oil and wax contamination of the vacuum lines is avoided, thus preventing the lifespan of the vacuum lines and vacuum detection components from being affected. The Roots pump can also serve as the vacuum pump for the degreasing component and as the backing pump for the high vacuum conditions required for vacuum degreasing. This allows for precise, step-by-step control to meet the vacuum level, pumping speed, and gas load requirements at different stages; efficient switching and isolation to avoid significant contamination during degreasing and reduce transition time; and a balance between high-throughput exhaust during the degreasing stage and high vacuum stability during the sintering stage. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of a degreasing and sintering vacuum device provided in an embodiment of this utility model;

[0046] Figure 2 This is a schematic diagram of the structure of a heat treatment furnace provided in an embodiment of this utility model;

[0047] Figure 3 This is a schematic diagram of another degreasing and sintering vacuum device provided in this embodiment of the present invention;

[0048] Figure 4 This is a schematic flowchart of a degreasing and sintering method provided in an embodiment of the present invention;

[0049] Figure 5 This is a schematic flowchart of another degreasing and sintering method provided in this embodiment of the present invention;

[0050] Figure 6 This is a schematic diagram of gas flow in a vacuum test provided by an embodiment of the present invention;

[0051] Figure 7This is another schematic diagram of gas flow for vacuum testing provided by an embodiment of the present invention;

[0052] Figure 8 This is a schematic diagram of gas flow during dewaxing provided in an embodiment of this utility model;

[0053] Figure 9 This is a schematic diagram of gas flow during vacuum sintering provided in an embodiment of the present invention;

[0054] Figure 10 This is a schematic diagram of gas flow in a vacuum full-evacuation sintering process provided by an embodiment of this utility model;

[0055] Figure 11 This is a schematic diagram of gas flow in a vacuum top-extraction sintering process provided by an embodiment of this utility model;

[0056] Figure 12 This is a schematic diagram of gas flow in a pressure-partitioned sintering process provided by an embodiment of this utility model;

[0057] Figure 13 This is a schematic diagram of gas flow in a pressure-partitioned sintering process provided by an embodiment of this utility model. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0059] Although the present invention can be readily embodied in various forms, only some specific embodiments are shown in the accompanying drawings and will be described in detail in this specification. It is understood that this specification should be regarded as an exemplary illustration of the principles of the present invention and is not intended to limit the present invention to what is described herein.

[0060] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present invention, and does not imply that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0061] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various elements of this invention are relative rather than absolute. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, these directional indications also change accordingly.

[0062] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of a degreasing and sintering vacuum device provided in an embodiment of this utility model. Figure 2 This is a schematic diagram of the structure of a heat treatment furnace 101 provided in an embodiment of the present utility model. The degreasing and sintering vacuum device may include: heat treatment furnace 101, first air extraction path 102, second air extraction path 103, air extraction pump assembly 104 and pressure detection assembly 105.

[0063] The heat treatment furnace 101 may include a furnace shell 1011 and an inner furnace 1012. The inner furnace 1012 is located inside the furnace shell 1011 and has a heating gap x1 between it and the furnace shell 1011. The inner furnace 1012 is permeable to gas. The inner furnace 1012 may be called a muffle furnace. The heat treatment furnace 101 may also include a heating element 1013 and an insulation layer. The heating element 1013 may be located outside the inner furnace 1012, that is, within the heating gap x1. The insulation layer may be located between the heating element 1013 and the furnace shell 1011, also within the heating gap x1. The inner furnace 1012 has a certain degree of permeability under high temperature or vacuum conditions. That is, some gas in the inner furnace 1012 may permeate into the heating gap x1 through the inner furnace 1012, and gas in the heating gap x1 may also permeate into the inner furnace 1012.

[0064] The inlet of the first exhaust passage 102 can be connected to the heating gap x1, and the outlet of the first exhaust passage 102 can be connected to the exhaust pump assembly 104. The inlet of the first exhaust passage 102 can be located in the heating gap x1 between the furnace shell 1011 and the inner furnace 1012. When the exhaust pump assembly 104 performs exhaust through the first exhaust passage 102, it can extract the gas in the heating gap x1 between the furnace shell 1011 and the inner furnace 1012 and discharge it into a preset space, which can refer to the exhaust pipe or the external environment.

[0065] The inlet of the second exhaust passage 103 can be connected to the interior of the inner furnace 1012, and the outlet of the second exhaust passage 103 can be connected to the exhaust pump assembly 104. The inlet of the second exhaust passage 103 can be located inside the inner furnace 1012. When the exhaust pump assembly 104 performs exhaust through the second exhaust passage 103, it can extract the gas inside the inner furnace 1012 and discharge it into a preset space.

[0066] The vacuum pump assembly 104 may include a Roots pump 1041 and a rotary vane pump 1042 connected in series. One end of the Roots pump 1041 is connected to the outlet of the first vacuum passage 102 and the outlet of the second vacuum passage 103, and the other end of the Roots pump 1041 is connected to the rotary vane pump 1042. The rotary vane pump 1042 has a gas ballast valve z1.

[0067] The inlet of the rotary vane pump 1042 is connected to the roots pump 1041, and the outlet of the rotary vane pump 1042 is connected to the exhaust pipe or the external environment. Because the pumping speed of the rotary vane pump 1042 decreases with decreasing pressure, the roots pump 1041 cannot be started from atmospheric pressure alone. Therefore, by combining the roots pump 1041 and the rotary vane pump 1042 into a pumping unit, with the rotary vane pump 1042 acting as a pre-pump and the roots pump 1041 as a booster pump, the heat treatment furnace 101 is first pumped from atmospheric pressure to the starting pressure of the roots pump 1041 via the rotary vane pump 1042, and then the roots pump 1041 quickly raises the vacuum level to the target vacuum level, thus improving pumping efficiency.

[0068] The rotary vane pump 1042 may have a gas ballast valve z1, which can improve the efficiency of the rotary vane pump 1042 in handling condensable gases (such as water vapor, solvent vapor, etc.) and prevent condensable gases from condensing and contaminating the pump oil in the rotary vane pump 1042.

[0069] The pressure detection component 105 can be used to detect the internal pressure of the furnace shell 1011 and the internal pressure of the inner furnace 1012. The heat treatment furnace 101 can be a double-layer structure, and the pressure detection component 105 can detect the pressure in each layer of the heat treatment furnace 101. For example, the pressure detection component 105 may include multiple pressure sensors or multiple pressure transmitters.

[0070] The degreasing and sintering vacuum device in this embodiment of the invention can perform vacuum treatment on the interior of the inner furnace 1012 and the heating gap x1 in the furnace shell 1011 through the first vacuum path 102 and the second vacuum path 103, respectively, so that the double-layer structure of the heat treatment furnace 101 is in a double-layer vacuum state. It can be understood that in the degreasing and sintering process, the first vacuum path 102 or the second vacuum path 103 can be used alone, or the first vacuum path 102 and the second vacuum path 103 can be used simultaneously, which can improve the process flexibility of the degreasing and sintering vacuum device.

[0071] In summary, this utility model embodiment provides a degreasing and sintering vacuum device including a heat treatment furnace 101, a first exhaust path 102, a second exhaust path 103, an exhaust pump assembly 104, and a pressure detection assembly 105. The heat treatment furnace 101 includes a furnace shell 1011 and an inner furnace 1012. The inner furnace 1012 is located inside the furnace shell 1011 and has a heating gap x1 between it and the furnace shell 1011. The inlet end of the first exhaust path 102 can communicate with the heating gap x1, and the inlet end of the second exhaust path 103 can communicate with the interior of the inner furnace 1012. The outlet ends of both the first exhaust path 102 and the second exhaust path 103 are connected to the exhaust pump assembly 104. Thus, the first exhaust path 102 and the second exhaust path 103 can respectively perform vacuum treatment on the interior of the inner furnace 1012 and the heating gap x1 within the furnace shell 1011, allowing the double-layer structure of the heat treatment furnace 101 to be in a double-layer vacuum state. It can prevent gas in the heating gap x1 from penetrating into the inner furnace 1012, maintain the vacuum level in the inner furnace 1012, and suppress gas in the inner furnace 1012 from penetrating into the heating gap x1, reducing the risk of process contamination, thereby enhancing the vacuum sealing reliability of the degreasing and sintering vacuum device.

[0072] Furthermore, if the material 30 releases combustible gas during sintering, the first exhaust path 102 can promptly remove the combustible gas. The first exhaust path 102 can prevent combustible gas from accumulating in the heating gap x1, thereby reducing the risk of explosion in the heat treatment furnace 101 and improving the safety of the degreasing and sintering vacuum device. In addition, the double-layer vacuum state can form a double heat insulation barrier. That is, by evacuating the interior of the inner furnace 1012, gas convection and heat conduction in the deheating inner box can be reduced, reducing heat loss from the material 30; by evacuating the heating gap x1, the heat radiation and conduction path to the outside of the furnace shell 1011 can be further blocked, thereby improving the temperature uniformity inside the heat treatment furnace 101.

[0073] Please refer to Figure 2 In one optional embodiment, the inner furnace 1012 may be made of graphite. Graphite exhibits good stability and thermal conductivity at high temperatures. Since graphite is formed by sintering carbon particles, the graphite inner furnace 1012 contains micron-sized pores. Therefore, under normal temperature and pressure, these pores may allow for trace gas permeation; under high temperature or high vacuum conditions, the gas permeability of the inner furnace 1012 will increase.

[0074] In one alternative embodiment, the inlet end of the first evacuation path 102 connects to the heating gap x1 from the top of the heat treatment furnace 101, and the inlet end of the second evacuation path 103 connects to the interior of the inner furnace 1012 from the bottom of the heat treatment furnace 101. This allows for vacuum extraction from the upper part of the heating gap x1 to efficiently capture the heated gas, conforming to natural convection principles and reducing evacuation energy consumption; vacuum extraction from the lower part of the inner furnace 1012 can stably extract gases or particles with higher density (such as unvolatile deposits).

[0075] In one exemplary embodiment, the inner furnace 1012 may include a cylindrical box t1 and end caps t2 located at both ends of the box t1, and the cylindrical box t1 and the two end caps t2 may both be made of graphite.

[0076] Please refer to Figure 1 In an optional real-time mode, the first exhaust path 102 may include a first pipe 1021 and a first valve 1022. The inlet of the first pipe 1021 is located between the furnace shell 1011 and the inner furnace 1012, and the outlet of the first pipe 1021 is connected to the exhaust pump assembly 104. The first valve 1022 is installed on the first pipe 1021. The inlet of the first pipe 1021 is connected to the heating gap x1, and the first valve 1022 can control the opening and closing of the first pipe 1021. For example, the first valve 1022 may include a solenoid valve, a pneumatic valve, etc.

[0077] The second exhaust passage 103 may include a second pipe 1031 and a second valve 1032. The air inlet of the second pipe 1031 is located in the inner furnace 1012, and the air outlet of the second pipe 1031 is connected to the exhaust pump assembly 104. The second valve 1032 is installed on the second pipe 1031. The air inlet of the second pipe 1031 is connected to the interior of the inner furnace 1012, and the second valve 1032 can control the opening and closing of the second pipe 1031. For example, the second valve 1032 may include a solenoid valve, a pneumatic valve, etc.

[0078] In one exemplary embodiment, the furnace shell 1011 has a first through hole, through which the air inlet of the first pipe 1021 extends into the furnace shell 1011; the furnace shell 1011 also has a second through hole, and the inner furnace 1012 has a third through hole, through which the air inlet of the second pipe 1031 extends into the inner furnace 1012; wherein, the first through hole is located on the side of the furnace shell 1011 away from the ground, the second through hole is located on the side of the furnace shell 1011 close to the ground, and the third through hole is located on the side of the inner furnace 1012 close to the ground.

[0079] Please refer to Figure 3 , Figure 3This is a schematic diagram of another degreasing and sintering vacuum device provided in an embodiment of the present invention. In an optional embodiment, the degreasing and sintering vacuum device may further include: a first connecting gas path 106 and a first regulating gas path 107 connected in parallel. The inlet end of the first connecting gas path 106 and the inlet end of the first regulating gas path 107 are both connected to the outlet of the first pipeline 1021 and the outlet of the second pipeline 1031. The outlet ends of the first connecting gas path 106 and the first regulating gas path 107 are both connected to the Roots pump 1041. The first regulating gas path 107 is used to regulate the gas flow rate of the first pipeline 1021 and the second pipeline 1031. The first pipeline 1021 and the second pipeline 1031 can both be connected to the vacuum pump assembly 104 through at least one of the first connecting gas path 106 and the first regulating gas path 107, which can improve the flexibility of the vacuum pumping direction.

[0080] Please refer to Figure 3 In one optional embodiment, the first connecting air passage 106 may include a third pipe 1061 and a third valve 1062. The air inlet of the third pipe 1061 is connected to the air outlet of the first pipe 1021 and the air outlet of the second pipe 1031, and the air outlet of the third pipe 1061 is connected to the Roots pump 1041. The third valve 1062 is installed on the third pipe 1061. The third valve 1062 can control the opening and closing of the third pipe 1061. For example, the third valve 1062 may include a solenoid valve, a pneumatic valve, etc.

[0081] The first regulating gas path 107 may include a fourth pipeline 1071, a fourth valve 1072, and a proportional valve 1073. The inlet of the fourth pipeline 1071 is connected to the outlet of the first pipeline 1021 and the outlet of the second pipeline 1031. The outlet of the fourth pipeline 1071 is connected to a Roots pump 1041. The fourth valve 1072 and the proportional valve 1073 are installed in parallel on the fourth pipeline 1071. The fourth valve 1072 can control the opening and closing of the fourth pipeline 1071. For example, the fourth valve 1072 may include a solenoid valve, a pneumatic valve, etc. The proportional valve 1073 can be used to control the flow rate of gas in the fourth pipeline 1071. For example, the proportional valve 1073 may include a solenoid proportional valve 1073, an electric proportional valve 1073, etc.

[0082] Please refer to Figure 3In an optional embodiment, the degreasing and sintering vacuum device may further include a gas filling component, which may include: a gas storage tank 108, a gas filling passage 109, a second connecting gas passage 110 and a second regulating gas passage 111 connected in parallel; the gas storage tank 108 is used to store inert gas; the inlet end of the second connecting gas passage 110 and the inlet end of the second regulating gas passage 111 are both connected to the gas storage tank 108, and the outlet end of the second connecting gas passage 110 and the outlet end of the second regulating gas passage 111 are both connected to the inner furnace 1012 through the gas filling passage 109; the second regulating gas passage 111 is used to regulate the gas flow rate of the gas filling passage 109. The inert gas may include argon (Ar). When it is necessary to adjust the inert gas flow rate, a preset flow rate of gas can be delivered to the filling gas path 109 through the second regulating gas path 111. When it is not necessary to adjust the inert gas flow rate, a preset flow rate of gas can be delivered to the filling gas path 109 through the second connecting gas path 110. In this way, the operating cost can be reduced.

[0083] Please refer to Figure 3 In one optional embodiment, the air supply path 109 may include a fifth pipe 1091 and a fifth valve 1092. The outlet of the fifth pipe 1091 is connected to the inner furnace 1012, and the fifth valve 1092 is installed on the fifth pipe 1091. The fifth valve 1092 can control the opening and closing of the fifth pipe 1091. For example, the fifth valve 1092 may include a solenoid valve, a pneumatic valve, etc.

[0084] The second connecting air passage 110 includes a sixth pipe 1101 and a sixth valve 1102. The air inlet of the sixth pipe 1101 is connected to the air storage tank 108, and the air outlet of the sixth pipe 1101 is connected to the air inlet of the fifth pipe 1091. The sixth valve 1102 is installed on the sixth pipe 1101. The sixth valve 1102 can control the opening and closing of the sixth pipe 1101. For example, the sixth valve 1102 may include a solenoid valve, a pneumatic valve, etc.

[0085] The second regulating gas path 111 includes a seventh pipeline and a mass flow controller 1112. The inlet of the seventh pipeline is connected to the gas storage tank 108, and the outlet of the seventh pipeline is connected to the inlet of the fifth pipeline 1091. The mass flow controller 1112 is installed on the seventh pipeline. The mass flow controller 1112 is a device for accurately measuring and controlling gas flow. It can automatically control the gas flow and maintain the flow rate at a set value even if the system pressure fluctuates or the ambient temperature changes. The mass flow controller 1112 can be used to regulate the gas flow rate in the seventh pipeline.

[0086] Please refer to Figure 3In an optional embodiment, the degreasing and sintering vacuum device may further include a wax collection assembly, which may include: an inlet pipe 112, a seventh valve 113, a wax collection cylinder 114, an outlet pipe 115, an eighth valve 116, and a mold temperature controller 117; the two ends of the inlet pipe 112 are respectively connected to the inner furnace 1012 and the wax collection cylinder 114, and the seventh valve 113 is installed on the inlet pipe 112; the two ends of the outlet pipe 115 are respectively connected to the wax collection cylinder 114 and the rotary vane pump 1042, and the eighth valve 116 is installed on the outlet pipe 115; the mold temperature controller 117 is connected to the wax collection cylinder 114. When the degreasing and sintering vacuum device in this embodiment of the present invention is working, the high-temperature gas in the inner furnace 1012 first enters the wax collection cylinder 114 through the inlet pipe 112 for cooling and liquefaction, and then exits through the outlet pipe 115; the liquefied liquid collects in the wax collection cylinder 114 and is discharged from the drain pipe of the wax collection cylinder 114. The mold temperature controller 117 controls the temperature inside the wax collection cylinder 114 by circulating heat transfer medium (oil or water) to ensure that the temperature inside the wax collection cylinder 114 is uniform.

[0087] Please refer to Figure 2 In an optional embodiment, the heat treatment furnace 101 may further include a heating element 1013, and the degreasing and sintering vacuum device may further include a cooling assembly, which may include a cooling fan 118, cooling fins 119, and cooling water channels 120. The heating element 1013 may include graphite rods, molybdenum-tungsten alloy rods, silicon carbide rods, etc.

[0088] Heating element 1013 is located in heating gap x1 and is used to provide heat to inner furnace 1012; cooling fan 118 is located inside furnace shell 1011 and at one end of inner furnace 1012; cooling fins 119 are located between cooling fan 118 and inner furnace 1012; cooling water passage 120 is connected to cooling fins 119. Both cooling fan 118 and cooling fins 119 can be installed inside furnace shell 1011; for example, both cooling fan 118 and cooling fins 119 can be bolted to furnace shell 1011. Cooling water passage 120 can be connected to a cooling water source, which may include a water storage tank or tap water pipe.

[0089] Please refer to Figure 3In one exemplary embodiment, the pressure detection assembly 105 may include a first pressure sensor 1051, a second pressure sensor 1052, a third pressure sensor 1053, a fourth pressure sensor 1054, and a fifth pressure sensor 1055. The first, second, and third pressure sensors 1051, 1052, and 1053 are all connected to the heating gap x1 to detect the pressure within the heating gap x1. The first, second, and third pressure sensors 1051 and 1052 are three pressure sensors with different measurement ranges. The measurement result of the first pressure sensor 1051 is measured in Pascals (Pa), the measurement result of the second pressure sensor 1052 is measured in millibars (mbar), and the measurement result of the third pressure sensor 1053 is measured in kilopascals (kPa). The fourth pressure sensor 1054 is installed on the air inlet pipe 112 and is used to detect the pressure in the inner furnace 1012. The measurement result of the fourth pressure sensor 1054 is measured in millibars (mbar). The fifth pressure sensor 1055 is installed on the air outlet pipe 115 and is used to detect the pressure in the wax collection cylinder 114. The measurement result of the fifth pressure sensor 1055 is in millibars (mbar).

[0090] The degreasing and sintering vacuum device may also include a temperature detection component, which may include a first temperature sensor 1211, a second temperature sensor 1212, and a third temperature sensor 1213. The first temperature sensor 1211 is installed on the air inlet pipe 112 and is used to detect the internal temperature of the air inlet pipe 112. The second temperature sensor 1212 is installed on the wax collection cylinder 114 and is used to detect the internal temperature of the wax collection cylinder 114. The third temperature sensor 1213 is installed on the rotary vane pump 1042 and is used to detect the internal temperature of the rotary vane pump 1042.

[0091] The degreasing and sintering vacuum device also includes a PLC control unit and a touch-screen interactive terminal. The PLC control unit can store preset process flows and can be electrically connected to multiple valves, heating elements 1013, temperature detection components, wax collection cylinders 114, and other components to ensure that the degreasing and sintering vacuum device operates according to the preset process flow. The touch-screen interactive terminal can have a parameter setting interface, through which operators can input process parameters.

[0092] Please refer to Figure 4 and Figure 1 , Figure 4 This is a schematic flowchart of a degreasing and sintering method provided in an embodiment of the present invention. The present invention also provides a degreasing and sintering method, which is used in the degreasing and sintering vacuum device in any of the above embodiments. The method includes the following steps:

[0093] Step 201: Open the first exhaust path to perform vacuum treatment inside the heat treatment furnace.

[0094] Step 202: Perform a vacuum test on the heat treatment furnace using a pressure detection component.

[0095] Step 203: Turn on the heating element in the heat treatment furnace to heat the material, and turn on at least one of the first and second exhaust paths to perform vacuum sintering treatment on the material.

[0096] Step 204: Shut down the heating elements and at least one gas path in the heat treatment furnace.

[0097] Please refer to Figure 5 , Figure 5 This is a schematic flowchart of another degreasing and sintering method provided in an embodiment of the present invention. The present invention also provides a degreasing and sintering method, which is used in the degreasing and sintering vacuum device in any of the above embodiments. The method includes the following steps:

[0098] Step 301: Open the first exhaust path to perform vacuum treatment inside the heat treatment furnace.

[0099] Please refer to Figure 6 , Figure 6 This is a schematic diagram of gas flow during vacuum testing provided by an embodiment of the present invention. The operator can manually start the rotary vane pump 1042, open the first valve 1022 on the first pipeline 1021, and open the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 to extract air from the heat treatment furnace 101. At this time, the furnace shell 1011 in the heat treatment furnace 101 is in a closed state, and the inner furnace 1012 is in an open state, that is, the end cover t2 of the inner furnace 1012 is in an open state, so that the inner furnace 1012 is connected to the heating gap x1. Simultaneously, the eighth valve 116 on the gas outlet pipe 115 is opened to extract residual gas from the wax collection cylinder 114.

[0100] Please refer to Figure 7 , Figure 7 This is another schematic diagram of gas flow for vacuum testing provided by this utility model embodiment. When the pressure inside the heat treatment furnace 101 reaches 20 mbar as detected by the second pressure sensor 1052, the third valve 1062 on the third pipeline 1061 is opened, and the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are closed.

[0101] When the pressure inside the heat treatment furnace 101 remains below 20 mbar, the eighth valve 116 on the gas outlet pipe 115 is closed, and after a delay of 30 seconds, the Roots pump 1041 is started.

[0102] Step 302: Conduct a vacuum test on the heat treatment furnace through the pressure detection component.

[0103] When the pressure inside the heat treatment furnace 101 detected by the first pressure sensor 1051 reaches the vacuum test vacuum degree, close the third pipeline 1061, the third valve 1062 and the Roots pump 1041, and conduct a 1-minute leakage test on the heat treatment furnace 101 through the pressure detection component 105; among them, the vacuum test vacuum degree can be preset by the operator in the touch screen parameter setting interface. Exemplarily, the vacuum test vacuum degree is 1 Pa to 3 Pa.

[0104] If the pressure increase inside the furnace of the heat treatment furnace 101 is less than or equal to the vacuum test allowable leakage value after 1 minute, it means the test is qualified, and step 303 is executed; if the pressure increase inside the furnace of the heat treatment furnace 101 exceeds the vacuum test allowable leakage value after 1 minute, step 301 and step 302 are executed again after a 1-minute delay. If the test is qualified, step 303 is executed, otherwise a vacuum test failure signal is sent to the PLC control component. Among them, the vacuum test allowable leakage value can be preset by the operator in the touch screen parameter setting interface. Exemplarily, the vacuum test allowable leakage value is 1 Pa.

[0105] Step 303: Turn on the heating element and the wax collection component to perform dewaxing treatment on the material.

[0106] Please refer to Figure 8 , Figure 8 which is a schematic diagram of gas flow for dewaxing treatment provided by an embodiment of the present invention. First, the air release valve z1 on the rotary vane pump 1042 can be opened, the rotary vane pump 1042 is turned on, the Roots pump 1041 is closed, and the eighth valve 116 on the air outlet pipeline 115 is opened to evacuate the wax collection cylinder 114 to a vacuum state. That is, when the pressure value of the measurement result of the fifth pressure sensor 1055 is lower than 2 mbar, it can be considered that the wax collection cylinder 114 is in a vacuum state.

[0107] Then, open the fifth valve 1092 on the fifth pipeline 1091. When the measured value of the fifth pressure sensor 1055 is lower than 2 mbar and the measured value of the fourth pressure sensor 1054 is less than 3 mbar, open the seventh valve 113 on the intake pipeline 112 and the sixth valve 1102 on the sixth pipeline 1101 to fill argon into the heat treatment furnace 101 through the intake port above the heat treatment furnace 101. Exemplarily, a flow meter can be provided at the outlet of the gas storage tank 108, and the flow rate of the gas entering the heat treatment furnace 101 can be adjusted through the flow meter.

[0108] When the pressure inside the heat treatment furnace 101 is detected to be greater than 4 mbar by the second pressure sensor 1052, the heating element 1013 is activated to start heating inside the heat treatment furnace 101. The degreasing and sintering vacuum device may also include a program controller, which can be electrically connected to the PLC control component. The program controller has a pre-stored degreasing process program. By starting the process program in the program controller, the material 30 can be dewaxed. The temperature rise curve can be recorded and displayed on the touch display interactive terminal so that the operator can observe the operation of the equipment.

[0109] Step 304: Turn on the heating element and the second extraction path to perform vacuum sintering treatment on the material.

[0110] Please refer to Figure 9 , Figure 9 This is a schematic diagram of gas flow in a vacuum sintering process provided by an embodiment of the present invention. First, the rotary vane pump 1042 is turned on, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned on, the eighth valve 116 on the outlet pipeline 115 is turned on, and the second valve 1032 on the second pipeline 1031 is turned on. When the pressure inside the heat treatment furnace 101 is detected to reach 20 mbar by the second pressure sensor 1052, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned off, the eighth valve 116 on the outlet pipeline 115 is turned off, the third valve 1062 on the third pipeline 1061 is turned on, and after a delay of 10 seconds, the Roots pump 1041 is started until the vacuum sintering process is completed.

[0111] Step 305: Turn on the heating element, the first exhaust path and the second exhaust path to perform vacuum full-extraction sintering treatment on the material.

[0112] Please refer to Figure 10 , Figure 10 This is a schematic diagram of gas flow in a vacuum sintering process provided by an embodiment of the present invention. First, the rotary vane pump 1042 is turned on, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned on, the eighth valve 116 on the outlet pipeline 115 is turned on, the second valve 1032 on the second pipeline 1031 is turned on, and the first valve 1022 on the first pipeline 1021 is turned on. When the pressure inside the heat treatment furnace 101 is detected to reach 20 mbar by the second pressure sensor 1052, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned off, the eighth valve 116 on the outlet pipeline 115 is turned off, the third valve 1062 on the third pipeline 1061 is turned on, and the Roots pump 1041 is started after a 10-second delay until the vacuum sintering process is completed.

[0113] Step 306: Turn on the heating element and the first exhaust path to perform vacuum sintering treatment on the material.

[0114] Please refer to Figure 11 , Figure 11 This is a schematic diagram of gas flow in a vacuum sintering process provided by an embodiment of the present invention. First, the rotary vane pump 1042 is turned on, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned on, the eighth valve 116 on the outlet pipeline 115 is turned on, and the first valve 1022 on the first pipeline 1021 is turned on. When the pressure inside the heat treatment furnace 101 is detected to reach 20 mbar by the second pressure sensor 1052, the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned off, the eighth valve 116 on the outlet pipeline 115 is turned off, the third valve 1062 on the third pipeline 1061 is turned on, and the Roots pump 1041 is started after a 10-second delay until the vacuum sintering process is completed.

[0115] Step 307: Turn on the heating element, the gas filling assembly and the first regulating gas path to perform partial pressure sintering treatment on the material.

[0116] Among them, partial pressure sintering is a sintering process carried out under specific atmospheric conditions. This process controls the partial pressure of the gas in the sintering environment to regulate the sintering behavior, microstructure and final properties of the material.

[0117] Please refer to Figure 3 In one exemplary embodiment, when the temperature inside the heat treatment furnace 101 rises and is under vacuum, the graphite inner furnace 1012 undergoes thermal expansion, causing the pores on the inner furnace 1012 to slightly enlarge. Furthermore, the free path of gas molecules increases, making it easier for gas to diffuse through the graphite pores, thus increasing the gas permeability on both the inner and outer sides of the inner furnace 1012. In this case, argon gas can be introduced into the heating gap x1 through the second connecting gas path 110 or the second regulating gas path 111. The argon gas in the heating gap x1 can permeate into the interior of the inner furnace 1012 under the influence of the pressure difference, thereby smoothly regulating the gas pressure in the sintering atmosphere within the inner furnace 1012. This achieves partial pressure sintering and prevents sudden changes in the vacuum level within the inner furnace 1012, improving the safety of the degreasing sintering vacuum device.

[0118] Please refer to Figure 12 , Figure 12This is a schematic diagram of gas flow in a pressure-partial sintering process according to an embodiment of the present invention. First, the rotary vane pump 1042 is turned on, the fifth valve 1092 on the fifth pipeline 1091 is turned on, the sixth valve 1102 on the sixth pipeline 1101 is turned on, and the fourth valve 1072 and the proportional valve 1073 on the fourth pipeline 1071 are turned on. The opening degree of the proportional valve 1073 is controlled by the second pressure sensor 1052 and the vacuum control instrument to control the pressure in the heat treatment furnace 101 within the set range.

[0119] It is understandable that, since the inner furnace 1012 is made of graphite, when argon is introduced into the furnace shell 1011 through the sixth pipe 1101 and the fifth pipe 1091, the argon in the furnace shell 1011 can penetrate into the inner furnace 1012, thereby uniformly regulating the gas pressure in the inner furnace 1012 and avoiding sudden changes in the gas pressure in the inner furnace.

[0120] It is understood that when actually using the degreasing and sintering method of this utility model embodiment, the operator can adaptively select and adjust the process steps according to the materials and production environment, and this utility model embodiment does not limit this. For example, in the same process, any one of the above steps 304, 305, 306 and 307 can be selected to perform the sintering process; or, at least two of the above steps 304, 305, 306 and 307 can be selected and combined, and the combined process steps can be performed.

[0121] For example, in one process, step 304 can be executed first to perform vacuum sintering on the material. After a period of time, step 306 can be executed simultaneously with step 304 to perform both vacuum sintering and vacuum top sintering on the material to avoid process contamination caused by gases permeating from the inner furnace. Then, steps 304 and 306 can be stopped, and step 307 can be executed to perform partial pressure sintering on the material to improve the mechanical properties (such as hardness and strength) of the sintered part through partial pressure sintering.

[0122] Step 308: Activate the inflation and cooling components to cool the material.

[0123] Please refer to Figure 13 and Figure 2 , Figure 13This is a schematic diagram of gas flow for cooling treatment provided by an embodiment of the present invention. First, when the temperature inside the heat treatment furnace 101 drops to the set temperature at which the end cover t2 of the inner furnace 1012 can be opened, the solenoid valve on the cooling water circuit 120 (not shown in the figure) is opened. After 10 seconds, the end cover t2 of the inner furnace 1012 is opened, the fifth valve 1092 on the fifth pipeline 1091 is opened, and the mass flow controller 1112 on the seventh pipeline is opened to fill the heat treatment furnace 101 with argon gas. The pressure inside the heat treatment furnace 101 is monitored in real time by the third pressure sensor 1053, and the pressure inside the heat treatment furnace 101 is maintained between -16KPa and -13KPa.

[0124] When the temperature inside the heat treatment furnace 101 drops to the set temperature for starting the cooling fan 118, and the pressure inside the heat treatment furnace 101 is below -16KPa, the cooling fan 118 is started after a one-minute delay until the temperature inside the heat treatment furnace 101 is reduced to the preset cooling temperature.

[0125] When the pressure inside the heat treatment furnace 101 during the cooling process exceeds -13 kPa, the mass flow controller 1112 is shut down. When the pressure inside the heat treatment furnace 101 during the cooling process exceeds -9 kPa, an alarm is issued. When the temperature of the cooling water in the heat dissipation fins 119 exceeds the preset temperature (e.g., exceeding 70°C), the cooling fan 118 is stopped, and an alarm is issued. All of the above-mentioned preset temperatures can be preset by the operator on the touchscreen parameter setting interface. For example, the heat treatment furnace 101 may have an audible and visual alarm 1014, which can issue the alarm.

[0126] In summary, this utility model embodiment provides a degreasing sintering method that can perform vacuum treatment on the interior of the inner furnace 1012 and the heating gap x1 within the furnace shell 1011 through at least one of the first vacuum path 102 and the second vacuum path 103. In the degreasing sintering process, the first vacuum path 102 or the second vacuum path 103 can be used alone, or both can be used simultaneously, which improves the process flexibility of the degreasing sintering vacuum device.

[0127] For example, if the material 30 releases combustible gas during sintering, the first extraction path 102 can remove the combustible gas in time, and the second extraction path 103 can prevent the combustible gas from accumulating in the heating gap x1, thereby reducing the risk of explosion in the heat treatment furnace 101 and improving the safety of the degreasing and sintering vacuum device. In addition, the first extraction path 102 and the second extraction path 103 can be used to vacuum the interior of the inner furnace 1012 and the heating gap x1 in the furnace shell 1011, respectively. The double vacuum state can form a double heat insulation barrier. That is, by vacuuming the interior of the inner furnace 1012, gas convection and heat conduction in the deheating inner box can be reduced, reducing heat loss from the material 30; by vacuuming the heating gap x1, the heat radiation and conduction path to the outside of the furnace shell 1011 can be further blocked, thereby improving the temperature uniformity inside the heat treatment furnace 101.

[0128] It should be noted that the dimensions of the areas may be exaggerated in the accompanying drawings for clarity. In the several embodiments provided by this utility model, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0129] In this invention, the terms "first," "second," "third," "fourth," "fifth," "sixth," "seventh," and "eighth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0130] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0131] The above description is only an optional embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A degreasing and sintering vacuum device, characterized in that, include: Heat treatment furnace, first exhaust path, second exhaust path and exhaust pump assembly; The heat treatment furnace includes a furnace shell and an inner furnace. The inner furnace is located inside the furnace shell and has a heating gap between it and the furnace shell. The inner furnace is capable of permeating gas. The air inlet of the first air extraction path is connected to the heating gap, and the air outlet of the first air extraction path is connected to the air pump assembly. The inlet of the second exhaust path is connected to the interior of the inner furnace, and the outlet of the second exhaust path is connected to the exhaust pump assembly. The air pump assembly includes a Roots pump and a rotary vane pump connected in series. One end of the Roots pump is connected to the outlet of the first air extraction path and the outlet of the second air extraction path, and the other end of the Roots pump is connected to the rotary vane pump. The rotary vane pump has a gas ballast valve.

2. The degreasing and sintering vacuum apparatus according to claim 1, characterized in that, The inlet end of the first exhaust path is connected to the heating gap from the top of the heat treatment furnace, and the inlet end of the second exhaust path is connected to the interior of the inner furnace from the bottom of the heat treatment furnace. The inner furnace includes a cylindrical box made of graphite and two end caps made of graphite, which are located at both ends of the box and are movably connected to the box.

3. The degreasing and sintering vacuum apparatus according to claim 1, characterized in that, The first exhaust path includes a first pipeline and a first valve. The inlet of the first pipeline is located between the furnace shell and the inner furnace, and the outlet of the first pipeline is connected to the exhaust pump assembly. The first valve is installed on the first pipeline. The second exhaust path includes a second pipeline and a second valve. The inlet of the second pipeline is located in the inner furnace, and the outlet of the second pipeline is connected to the exhaust pump assembly. The second valve is installed on the second pipeline. One end of the Roots pump is connected to the air outlet of the first pipeline and the air outlet of the second pipeline.

4. The degreasing and sintering vacuum apparatus according to claim 3, characterized in that, The degreasing and sintering vacuum device further includes: a first connecting gas path and a first regulating gas path connected in parallel; The air inlet of the first connecting air passage and the air inlet of the first regulating air passage are both connected to the air outlet of the first pipeline and the air outlet of the second pipeline, and the air outlet of the first connecting air passage and the air outlet of the first regulating air passage are both connected to the Roots pump. The first regulating gas path is used to regulate the gas flow rate of the first pipeline and the second pipeline.

5. The degreasing and sintering vacuum apparatus according to claim 4, characterized in that, The first connecting air passage includes a third pipeline and a third valve. The air inlet of the third pipeline is connected to the air outlet of the first pipeline and the air outlet of the second pipeline. The air outlet of the third pipeline is connected to the Roots pump. The third valve is installed on the third pipeline. The first regulating air path includes a fourth pipeline, a fourth valve, and a proportional valve. The air inlet of the fourth pipeline is connected to the air outlet of the first pipeline and the air outlet of the second pipeline. The air outlet of the fourth pipeline is connected to the Roots pump. The fourth valve and the proportional valve are installed in parallel on the fourth pipeline.

6. The degreasing and sintering vacuum apparatus according to claim 3, characterized in that, The degreasing and sintering vacuum device also includes: a gas storage tank, a gas filling line, a second connecting gas line and a second regulating gas line connected in parallel; The gas storage tank is used to store inert gas; The inlet end of the second connecting gas path and the inlet end of the second regulating gas path are both connected to the gas storage tank. The outlet end of the second connecting gas path and the outlet end of the second regulating gas path are both connected to the inner furnace through the charging gas path. The second regulating gas path is used to regulate the gas flow rate of the charging gas path.

7. The degreasing and sintering vacuum apparatus according to claim 6, characterized in that, The gas filling circuit includes a fifth pipeline and a fifth valve. The outlet of the fifth pipeline is connected to the inner furnace, and the fifth valve is installed on the fifth pipeline. The second connecting gas path includes a sixth pipeline and a sixth valve. The inlet of the sixth pipeline is connected to the gas storage tank, the outlet of the sixth pipeline is connected to the inlet of the fifth pipeline, and the sixth valve is installed on the sixth pipeline. The second regulating gas path includes a seventh pipeline and a mass flow controller. The inlet of the seventh pipeline is connected to the gas storage tank, and the outlet of the seventh pipeline is connected to the inlet of the fifth pipeline. The mass flow controller is installed on the seventh pipeline.

8. The degreasing and sintering vacuum apparatus according to claim 3, characterized in that, The degreasing and sintering vacuum device also includes: an air inlet pipe, a seventh valve, a wax collection cylinder, an air outlet pipe, an eighth valve, and a mold temperature controller; The two ends of the air inlet pipe are respectively connected to the inner furnace and the wax collection cylinder, and the seventh valve is installed on the air inlet pipe; The two ends of the air outlet pipe are respectively connected to the wax collection cylinder and the rotary vane pump, and the eighth valve is installed on the air outlet pipe; The mold temperature controller is connected to the wax collection cylinder.

9. The degreasing and sintering vacuum apparatus according to claim 1, characterized in that, The heat treatment furnace further includes a heating element, and the degreasing and sintering vacuum device further includes a heat dissipation fan, heat dissipation fins, and cooling water circuit. The heating element is located in the heating gap; The cooling fan is located inside the furnace shell and at one end of the inner furnace; The heat dissipation fins are located between the heat dissipation fan and the inner furnace; The cooling water path is connected to the heat dissipation fins.

Images