Powder Metallurgy Sintering Furnace

Abstract

The present invention relates to the technical field of powder metallurgy, and specifically to a powder metallurgy sintering furnace. It includes a furnace body and a furnace cover. The furnace body is connected to the furnace cover. An electric heating element for heating the interior of the furnace body is installed on the furnace body. An exhaust pipe communicating with the interior of the furnace body is installed on the furnace cover. One end of the exhaust pipe is connected to the furnace cover, and the other end extends through the furnace body or the furnace cover to the bottom of the furnace body and passes through the furnace cover through the bottom to expose outside the furnace body, so that an auxiliary heating section is formed in the furnace body by the exhaust pipe, and the auxiliary heating section is arranged near the central position of the furnace body; an exhaust port is arranged at the other end of the exhaust pipe, and the inner diameter of the exhaust port is smaller than the inner diameter of the exhaust pipe; a gas supply pipe for supplying combustible gas to the interior of the furnace body is arranged on the furnace body. The powder metallurgy sintering furnace provided by the present invention enables the heat carried in the airflow to have a more sufficient heat exchange time with the powder, reducing energy waste.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy, and particularly to a powder metallurgy sintering furnace. Background Art

[0002] Powder metallurgy is a process technology for producing metal powders or using metal powders (or mixtures of metal powders and non-metal powders) as raw materials, and manufacturing metal materials, composite materials, and various types of products through forming and sintering. A powder metallurgy sintering furnace is an important equipment for powder metallurgy. An existing powder metallurgy sintering furnace is provided with electric heating elements on the furnace body to heat the powder in the furnace body, and a gas supply pipe is provided to cooperate with the electric heating elements to heat the powder in the furnace body to improve the efficiency of the temperature rise in the furnace body. An exhaust pipe is provided on the furnace cover to discharge waste gas. This structure has the following technical problems:

[0003] 1. The high temperature in the furnace body directly diffuses outwards along the exhaust pipe, resulting in waste of energy;

[0004] 2. When the powder accumulates in the furnace body, the powder on the inner side relies on the powder on the outer side to be heated and then heat-transfer to increase the temperature, resulting in uneven heating. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the present invention provides a powder metallurgy sintering furnace to solve at least one of the above technical problems.

[0006] In order to achieve the above invention purpose, the technical solution provided by the present invention is as follows:

[0007] A powder metallurgy sintering furnace, comprising a furnace body and a furnace cover, the furnace body is connected to the furnace cover, an electric heating element for heating the inside of the furnace body is installed on the furnace body, an exhaust pipe communicating with the inside of the furnace body is installed on the furnace cover, one end of the exhaust pipe is connected to the furnace cover, and the other end passes through the furnace body or the furnace cover and extends to the bottom of the furnace body and passes through the furnace cover through the bottom to expose outside the furnace body, so that an auxiliary heating section is formed in the furnace body by the exhaust pipe, and the auxiliary heating section is arranged near the central position of the furnace body; an exhaust port is provided at the other end of the exhaust pipe, and the inner diameter of the exhaust port is smaller than the inner diameter of the exhaust pipe; a gas supply pipe for supplying combustible gas to the inside of the furnace body is provided on the furnace body.

[0008] Preferably, the exhaust pipe passes through the furnace body and extends to the bottom of the furnace body, and is arranged in a spiral shape at a position near the bottom in the furnace body.

[0009] Preferably, the exhaust duct extends through the furnace lid to the bottom of the furnace body, forming a vertical section between the bottom and the furnace lid, and the vertical section is located at the central position of the furnace body; a section of the exhaust duct that passes through the furnace lid from the bottom and exposes outside the furnace body is arranged in a spiral shape at a position near the bottom inside the furnace body, so that a spiral section is formed on the exhaust duct, and the spiral section is located outside the vertical section.

[0010] Preferably, a valve is installed on the gas supply duct; a pressure relief valve is installed on the part of the exhaust duct located outside the furnace body; a heat insulation layer is provided on the part of the exhaust duct located outside the furnace body.

[0011] Preferably, a cylindrical inner cavity is provided on the exhaust duct, and the cylindrical inner cavity divides the interior of the exhaust duct into a first exhaust passage and a second exhaust passage. The cylindrical inner cavity is respectively communicated with the first exhaust passage and the second exhaust passage, and the first exhaust passage is communicated with the interior of the furnace body; an X-shaped filter screen is arranged in the cylindrical inner cavity, a central shaft is installed at the central position of the X-shaped filter screen, and a motor for driving the central shaft to rotate is installed on the exhaust duct; a chip discharge port is arranged at a position corresponding to the cylindrical inner cavity on the exhaust duct, and the chip discharge port is arranged close to the second exhaust passage.

[0012] Preferably, an arc-shaped shielding piece is arranged at one end of the X-shaped filter screen far from the central shaft, and the width of the arc-shaped shielding piece is greater than the width of the chip discharge port.

[0013] Preferably, the width of the arc-shaped shielding piece is greater than or equal to half of the maximum distance between two adjacent filter pieces of the X-shaped filter screen; wherein, the maximum distance between two adjacent filter pieces: the distance between the ends of two adjacent filter pieces far from the central shaft; the widths of the first exhaust passage and the second exhaust passage are less than or equal to half of the maximum distance between two adjacent filter pieces of the X-shaped filter screen.

[0014] Optionally, the central shaft is fixedly connected to the X-shaped filter screen.

[0015] Preferably, the central shaft is connected to the X-shaped filter screen through a torsion spring; the central position of the X-shaped filter screen is a circular tube, the central shaft passes through the circular tube and is rotationally connected to the circular tube; a torsion spring is sleeved at one end of the central shaft far from the motor, one end of the torsion spring is fixed on the central shaft, and the other end is fixed on the circular tube.

[0016] Preferably, a convex portion is arranged at one end of the circular tube far from the motor; one end of the torsion spring passes through the central shaft, and the other end passes through the convex portion.

[0017] When the powder metallurgy sintering furnace provided by the present invention is in use, powder to be heated is placed in the furnace body. Combustible gas is supplied to the furnace body through a gas supply pipe to heat the powder, and an electric heating element is used to assist the combustible gas in heating the powder, enabling the powder to heat up more quickly. During the heating process of the powder, the air pressure in the furnace body increases, causing air to flow through the exhaust pipe into the auxiliary heating section. The heat carried by the air exchanges heat with the powder at the middle position, making the heating more uniform. Since the inner diameter of the exhaust port is smaller than that of the exhaust pipe, the air flow is blocked during the process of discharging outward, allowing more sufficient heat exchange time between the heat carried by the air flow and the powder, and reducing energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. shows the structural schematic diagram of the powder metallurgy sintering furnace in Embodiment 1;

[0019] Figure 2 FIG. shows the structural schematic diagram of the powder metallurgy sintering furnace in Embodiment 2;

[0020] Figure 3 FIG. shows the schematic diagram of the dust-proof structure of the powder metallurgy sintering furnace in Embodiment 3;

[0021] Figure 4 FIG. shows the schematic diagram of the installation structure of a torsion spring;

[0022] Figure 5 FIG. shows one of the schematic diagrams of the dust-proof structure of the powder metallurgy sintering furnace in Embodiment 4;

[0023] Figure 6 FIG. shows the second schematic diagram of the dust-proof structure of the powder metallurgy sintering furnace in Embodiment 2;

[0024] Reference signs in the drawings:

[0025] Furnace body 100, furnace cover 200, electric heating element 300, gas supply pipe 400, valve 500, pressure relief valve 600, heat preservation layer 700, vertical section 701, spiral section 702;

[0026] Exhaust pipe 1, inner cavity 1-1, first exhaust passage 1-3, second exhaust passage 1-2, chip discharge port 1-4, exhaust port 1-5; X-shaped filter net 2, arc-shaped baffle 2-1, round pipe 2-2, filter sheet 2A; central shaft 3, torsion spring 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Example 1. Refer to Figure 1 , this application provides a powder metallurgy sintering furnace, including a furnace body 100 and a furnace cover 200. The furnace body is connected to the furnace cover. During production, the furnace cover can be located on the furnace body and is detachably connected to the furnace body. Preferably, it is hermetically connected to the furnace cover through a sealing ring, etc. An electric heating element 300 for heating the interior of the furnace body is installed on the furnace body. An exhaust duct 1 communicating with the interior of the furnace body is installed on the furnace cover. One end of the exhaust duct is connected to the furnace cover, and the other end passes through the furnace body and extends to the bottom of the furnace body and passes through the furnace cover to expose outside the furnace body, so that an auxiliary heating section is formed in the furnace body by the exhaust duct. The auxiliary heating section is arranged near the central position of the furnace body. The exhaust duct is arranged in a spiral shape at a position near the bottom in the furnace body; an exhaust port 1-5 is provided at the other end of the exhaust duct. The inner diameter of the exhaust port is smaller than the inner diameter of the exhaust pipe; a gas supply pipe 400 for supplying combustible gas to the interior of the furnace body is provided on the furnace body. A valve 500 is preferably installed on the gas supply pipe. A pressure relief valve 600 is installed on the part of the exhaust duct located outside the furnace body; a heat insulation layer 700 is provided on the part of the exhaust duct located outside the furnace body. In this embodiment, a plurality of air outlet holes communicating with the gas supply pipe can be circumferentially arranged on the furnace body to facilitate the uniform combustion of the combustible gas in the furnace body. An igniter can be provided at the outlet position of the gas supply pipe in the furnace body to facilitate the ignition of the combustible gas. Of course, the combustible gas can also be ignited by the electric heating element, which is well known to those skilled in the art and will not be elaborated here.

[0029] When the above powder metallurgy sintering furnace is in use, the powder to be heated is placed in the furnace body. Combustible gas is supplied to the furnace body through the gas supply pipe to heat the powder, and the electric heating element is used to assist the combustible gas to heat the powder, so that the powder can be heated more quickly. During the heating process of the powder, the air pressure in the furnace body increases, so that air flows through the exhaust duct into the spiral part. The heat carried by the air flow exchanges heat with the powder at the middle position, making the heating more uniform; since the inner diameter of the exhaust port is smaller than the inner diameter of the exhaust pipe, the air flow is blocked during the process of flowing outwards, so that the heat carried by the air flow has more sufficient heat exchange time with the powder, reducing the waste of energy. The setting of the heat insulation layer can reduce the heat transfer to the outside world, which is beneficial to the reuse of heat. The pressure relief valve prevents the air pressure in the furnace body from being too high.

[0030] Example 2. Refer to Figure 2, Embodiment 2 is generally the same as Embodiment 1, except that: the exhaust pipe extends through the furnace cover to the bottom of the furnace body, forming a vertical section 701 between the bottom and the furnace cover, and the vertical section is located at the central position of the furnace body; a section of the exhaust pipe that passes through the furnace cover through the bottom and exposes outside the furnace body is arranged in a spiral shape at a position near the bottom inside the furnace body, so that a spiral section 702 is formed on the exhaust pipe, and the spiral section is located outside the vertical section. In the furnace body with this structure, the air flow generated by heating enters the vertical section through the exhaust pipe. After the heat carried by the air flow exchanges heat with the powder once at the middle position, it then exchanges heat with the powder near the middle position through the spiral section. In this way, heat exchange is carried out in layers, further reducing energy waste. In addition, the powder near the vertical section is farther from the powder on the outer side than the powder near the spiral section. Therefore, the temperature rising speed of the powder relying on heat transfer from the outer side is relatively slow. The above structural design enables the heat of the exhaust pipe to first exchange heat with the powder at the middle position, and then conduct secondary exchange with the powder around it, making the overall heating of the powder more uniform.

[0031] Embodiment 3, based on Embodiment 1 or Embodiment 2, as a preferred embodiment, see Figure 3 , a cylindrical inner cavity 1-1 is provided on the exhaust pipe. The cylindrical inner cavity divides the interior of the exhaust pipe into a first exhaust channel 1-3 and a second exhaust channel 1-2. The cylindrical inner cavity is respectively communicated with the first exhaust channel and the second exhaust channel. The first exhaust channel is communicated with the interior of the furnace body, and a pressure relief valve is provided corresponding to the second exhaust pipe; an X-shaped filter screen 2 is provided in the cylindrical inner cavity. A central shaft 3 is installed at the central position of the X-shaped filter screen, and a motor for driving the central shaft to rotate is installed on the exhaust pipe; a chip discharge port 1-4 is provided on the exhaust pipe corresponding to the position of the cylindrical inner cavity, and the chip discharge port is arranged near the second exhaust channel. When this structure is in use, the second exhaust channel is connected to the exhaust port of the powder metallurgy sintering furnace. When the powder metallurgy sintering furnace is working, the generated dust rises with the air flow and is blocked by the X-shaped filter screen. When the two filter pieces below the X filter screen are blocked or within a certain period of time, the motor drives the X-shaped filter screen to rotate, so that the two filter pieces below the X filter screen rotate counterclockwise by 90 degrees (the rotation direction is shown by the arrow). Under the action of gravity, the dust attached to the two filter pieces finally discharges through the chip discharge port, so that the filter screen can be prevented from being blocked without the need for staff to clean it frequently.

[0032] During actual production, the central shaft and the X-shaped filter screen can be fixedly connected. As a preferred embodiment, see Figure 4, the central axis is connected to the X-shaped filter net through a torsion spring. During specific manufacturing, the central position of the X-shaped filter net can be a circular tube 2-2, and the central axis passes through the circular tube and is rotatably connected to the circular tube; a torsion spring 4 is sleeved on the end of the central axis away from the motor. One end of the torsion spring is fixed on the central axis, and the other end is fixed on the circular tube. The fixing method can use existing methods such as welding and clamping. In this embodiment, a convex portion is provided at the end of the circular tube away from the motor; one end of the torsion spring passes through the central axis, and the other end passes through the convex portion. When in use, when the motor rotates, the motor drives, and the torsion spring first deforms to generate elastic force. When the motor stops rotating, the X-shaped filter net continues to rotate under the action of inertia until the torsion spring reaches the maximum rebound force and then rotates in the opposite direction and finally stops. During this process, the X filter net moves repeatedly, making it more difficult for dust to adhere to the filter net, which is beneficial to the shedding of dust on the filter net; in this embodiment, the motor can use a general AC motor, and preferably a stepper motor.

[0033] Example 4, please refer to Figure 5 , the structure of Example 4 is substantially the same as that of Example 3, except that: an arc-shaped shielding piece 2-1 is provided at the end of the X-shaped filter net away from the central axis, and the width of the arc-shaped shielding piece is greater than the width of the chip discharge port. When the powder metallurgy sintering furnace of this embodiment is in use, the second exhaust passage is connected to the exhaust port of the powder metallurgy sintering furnace. When the powder metallurgy sintering furnace is working, the generated dust rises with the air flow and is blocked by the X-shaped filter net. When the two filter pieces below the X filter net are blocked or within a certain period of time, the motor drives the X-shaped filter net to rotate, so that the two filter pieces below the X filter net rotate clockwise by 90 degrees (the rotation direction is shown by the arrow). Under the action of gravity, the dust attached to the two filter pieces finally reaches the lower filter piece. Subsequently, the motor drives the two filter pieces below the X filter net to rotate clockwise by 90 degrees again, and the dust approaches the left filter piece. Then the motor drives the two filter pieces below the X filter net to rotate clockwise by 90 degrees again. Under the action of gravity, the dust attached to the two filter pieces finally discharges from the chip discharge port. In this way, it is not necessary for the staff to clean the filter net frequently to prevent the filter net from being blocked. The dust passes through the three rotations of the filter net, especially under the action of the torsion spring, through three vibrations, making it more difficult for the dust to adhere to the filter net, which is beneficial to the shedding of dust on the filter net.

[0034] During actual manufacturing, the width of the arc-shaped shielding piece can be less than half of the maximum distance between two adjacent filter pieces 2A of the X-shaped filter net. Among them, the maximum distance between two adjacent filter pieces: the distance between the ends of two adjacent filter pieces away from the central axis. At this time, the widths of the first exhaust passage and the second exhaust passage are preferably greater than or equal to half of the maximum distance between two adjacent filter pieces 2A of the X-shaped filter net. As a preferred implementation method, refer to Figure 6, the width of the arc-shaped baffle is greater than or equal to half of the maximum distance between two adjacent filter sheets 2A of the X-shaped filter net. Among them, the maximum distance between two adjacent filter sheets 2A: the distance between the ends of two adjacent filter sheets away from the central axis. The widths of the first exhaust passage and the second exhaust passage are preferably less than or equal to half of the maximum distance between two adjacent filter sheets 2A of the X-shaped filter net. In this way, when dust rises with the airflow and is blocked by the X-shaped filter net, after the right filter sheet rotates 90 degrees clockwise on the X-shaped filter net, the left filter net sheet is located above it, and the attached dust falls onto it. Then, after the X-shaped filter net rotates 90 degrees clockwise again, the dust accumulates near the filter sheet on the right (the left side in the existing state). The arc-shaped baffle has a certain blocking effect on it above. Then, after the X-shaped filter net rotates 90 degrees clockwise again, under the action of gravity, the dust attached to the two filter sheets finally discharges from the chip discharge port; during the rotation of the X-shaped filter net in this structure, the airflow can maintain the flow through the second exhaust passage - filter net - first exhaust passage.

[0035] It should be noted that the phrases such as "an embodiment", "embodiment", "exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include specific features, structures or characteristics, but not necessarily every embodiment includes such specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. Moreover, when combining specific features, structures or characteristics with an embodiment, it is within the knowledge scope of those skilled in the art to implement such features, structures or characteristics in combination with other embodiments, whether explicitly or implicitly described.

[0036] It should be easily understood that the terms "on...", "above...", and "over..." in this disclosure should be interpreted in the broadest manner, so that "on..." not only means "directly on something", but also includes the meaning of "on something" with intermediate features or layers therebetween, and "above..." or "over..." not only includes the meaning of "above something" or "over something", but also can include the meaning of "above something" or "over something" without intermediate features or layers therebetween (i.e., directly on something).

[0037] In addition, for the convenience of description, spatial relative terms such as "below", "beneath", "under", "above", "over", etc. may be used in the text to describe the relationship of one element or feature relative to other elements or features as shown in the figure. Spatial relative terms are intended to include different orientations of the device in use or operation other than the orientation shown in the drawings. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptive words used in the text can be interpreted accordingly.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0039] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A powder metallurgy sintering furnace, comprising a furnace body (100) and a furnace cover (200), wherein the furnace body is connected to the furnace cover, an electric heating element (300) for heating the interior of the furnace body is installed on the furnace body, and an exhaust pipe (1) communicating with the interior of the furnace body is installed on the furnace cover, characterized in that: One end of the exhaust duct is connected to the furnace cover, and the other end passes through the furnace body or the furnace cover to extend to the bottom of the furnace body and passes through the furnace cover through the bottom to be exposed outside the furnace body, so that the exhaust duct forms an auxiliary heating section in the furnace body, and the auxiliary heating section is arranged near the center of the furnace body; An exhaust port (1-5) is provided at the other end of the exhaust pipe, and the inner diameter of the exhaust port is smaller than the inner diameter of the exhaust pipe; The furnace body is provided with a gas supply pipeline (400) for supplying combustible gas to the interior of the furnace body; The exhaust duct is provided with a cylindrical inner chamber (1-1), the cylindrical inner chamber divides the interior of the exhaust duct into a first exhaust channel (1-3) and a second exhaust channel (1-2), the cylindrical inner chamber is communicated with the first exhaust channel and the second exhaust channel respectively, and the first exhaust channel is communicated with the interior of the furnace body; An X-shaped filter screen (2) is arranged in the cylindrical inner chamber, a central shaft (3) is installed at the center of the X-shaped filter screen, and a motor for driving the central shaft to rotate is installed on the exhaust pipe; A chip removal opening (1-4) is arranged on the exhaust duct at a position corresponding to the cylindrical inner chamber, and the chip removal opening is arranged close to the second exhaust channel; An arc-shaped shielding piece (2-1) is provided at one end of the X-shaped filter screen away from the central axis, and the width of the arc-shaped shielding piece is greater than the width of the chip removal opening; The width of the arc-shaped shielding sheet is greater than or equal to half of the maximum distance between two adjacent filter sheets (2A) of the X-shaped filter screen; The maximum distance between two adjacent filter sheets is the distance between two adjacent filter sheets away from one end of the central axis; The width of the first exhaust channel and the second exhaust channel is less than or equal to half of the maximum distance between two adjacent filter sheets of the X-shaped filter screen.

2. A powder metallurgy sintering furnace according to claim 1, characterized in that: The exhaust duct extends through the furnace body to the bottom of the furnace body, and is arranged in a spiral shape at a position near the bottom of the furnace body.

3. A powder metallurgy sintering furnace according to claim 1, characterized in that: The exhaust duct passes through the furnace cover and extends to the bottom of the furnace body, forming a vertical section (701) between the bottom and the furnace cover, and the vertical section is located at the center of the furnace body; The exhaust duct passes through the furnace cover through the bottom and is exposed outside the furnace body. A section is arranged in a spiral shape near the bottom of the furnace body, so that a spiral section (702) is formed on the exhaust duct. The spiral section is located outside the vertical section.

4. The powder metallurgy sintering furnace according to claim 1, characterized in that: A valve (500) is installed on the gas supply pipeline; A pressure relief valve (600) is installed on the portion of the exhaust pipe located outside the furnace body; A heat-insulating layer (700) is provided on the portion of the exhaust duct located outside the furnace body.

5. The powder metallurgy sintering furnace according to claim 1, characterized in that: The central axis is fixedly connected to the X-shaped filter screen.

6. The powder metallurgy sintering furnace according to claim 1, characterized in that: The central shaft is connected to the X-shaped filter screen via a torsion spring; The center position of the X-shaped filter screen is a circular tube (2-2), and the central axis passes through the circular tube and is rotatably connected to the circular tube; A torsion spring (4) is sleeved on one end of the central shaft away from the motor, one end of the torsion spring is fixed on the central shaft, and the other end is fixed on the round tube.

7. A powder metallurgy sintering furnace according to claim 6, characterized in that: A protrusion is provided at one end of the circular tube away from the motor; One end of the torsion spring passes through the central shaft, and the other end passes through the protruding portion.

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