WO2018223439A1

WO2018223439A1 - Vacuum sintering furnace enabling continuous production

Info

Publication number: WO2018223439A1
Application number: PCT/CN2017/090430
Authority: WO
Inventors: 骆接文; 林利宏
Original assignee: 深圳市星特烁科技有限公司
Priority date: 2017-06-09
Filing date: 2017-06-28
Publication date: 2018-12-13
Also published as: TWM556837U; CN206869125U

Abstract

A vacuum sintering furnace enabling continuous production, the furnace comprising a main body (100), a feed replacement chamber (200), and a discharge replacement chamber (300). The feed replacement chamber comprises a first chamber door (220) open to an ambient environment and a second chamber door (230) open to the main body. The discharge replacement chamber comprises a third chamber door (320) open to the ambient environment and a fourth chamber door (330) open to the main body. The first, second, third, an fourth chamber doors can be opened or closed independently. The first and/or second chamber doors and the third and/or fourth chamber doors are closed at the same time to ensure that an internal space of the main body is kept in a vacuum state during operation. The vacuum sintering furnace enables the main body to perform continuous heating and remain in a vacuum state, thus eliminating the process in which air evacuation, heating, temperature holding, and cooling need to be frequently performed, and improving production efficiency to facilitate large-scale production.

Description

Vacuum sintering furnace capable of continuous production

Technical field

The invention relates to the field of powder metallurgy and metal/nonmetal heat treatment, in particular to a sintering device for metal injection molding, in particular to a sintering furnace.

Background technique

Metal Injection Molding (MIM) is a new powder metallurgy forming technology that has been extended from the plastic injection molding industry. The basic process steps are: first select the metal powder and binder that meet the MIM requirements, and then adopt the appropriate method at a certain temperature. The powder and the binder are mixed into a uniform feed, which is granulated and then injected into a mold by an injection molding machine, and the obtained shaped preform is degreased and then sintered at a high temperature to become a final product.

At present, MIM high-temperature sintering equipment mainly includes batch type sintering furnace, and batch type sintering furnace is most commonly used as vacuum sintering furnace. Each time the vacuum sintering furnace is operated, the workpiece to be sintered is sent to the furnace body by manual or robotic loading, and each time the furnace is opened, the following processes are required: charging→closing the furnace door→vacuum→heating and heating→ Insulation → cooling → opening the furnace door → discharging, which leads to the low productivity of the existing vacuum sintering furnace, which cannot meet the requirements of continuous and large-scale production.

Summary of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a vacuum sintering furnace capable of achieving continuous production, so as to solve the problem that the existing vacuum sintering furnace has low productivity and cannot meet the requirements of continuity and large-scale production.

The technical solution adopted by the present invention to solve the technical problem thereof is:

A vacuum sintering furnace capable of continuous production, comprising a furnace body, a feed replacement tank and a discharge replacement tank, wherein the feed replacement tank comprises a first hatch leading to the outside and a second hatch leading to the furnace body, The material replacement chamber includes a third hatch leading to the outside and a fourth hatch leading to the furnace body, and the first hatch, the second hatch door, the third hatch door and the fourth hatch door can be independently opened and closed, wherein A hatch and/or a second hatch are simultaneously closed with the third hatch and/or the fourth hatch to ensure that the internal space of the furnace body maintains a vacuum during operation.

As a further improvement of the above scheme, the first material transfer device for feeding the material from the feed replacement tank to the furnace body is further included.

As a further improvement of the above solution, a second material transfer device that pushes the material to move inside the furnace body is also included.

As a further improvement of the above solution, the third material transfer device for feeding the material from the furnace body to the discharge replacement tank is further included.

As a further improvement of the above solution, the fourth material transfer device for feeding the material from the discharge replacement tank is further included.

As a further improvement of the above solution, a return line connecting the feed replacement chamber and the discharge replacement chamber is also included.

As a further improvement of the above solution, the return line includes a first return line connected to the feed replacement chamber, a second return line connected to the discharge replacement chamber, and a first return line and a second return line connected The third return line.

As a further improvement of the above solution, the method further comprises: transporting the material from the third return line to the fifth material transfer device of the first return line, and transporting the material from the first return line to the sixth material of the feed replacement tank. The transfer device transports the material from the second return line to the seventh material transfer device of the third return line, and the eighth material transfer device that pushes the material to move on the third return line.

As a further improvement of the above scheme, there are also several carriers which are sequentially arranged on the return line and movable relative to the return line.

As a further improvement of the above solution, the furnace body is provided with a heating zone and a cooling zone in the direction of the feed replacement tank to the discharge replacement tank.

The beneficial effects of the invention are:

The furnace body can be continuously maintained in the heating and vacuum state, eliminating the process of frequent vacuuming, heating, heat preservation and temperature reduction inside the furnace body, thereby greatly improving the production efficiency and being more suitable for large-scale production.

In a preferred embodiment of the invention, a plurality of material transfer devices are also provided to achieve an automated supply of materials.

In a preferred embodiment of the invention, a return line is also provided to achieve reflow of the carrier, further increasing production efficiency.

DRAWINGS

The invention will now be further described with reference to the drawings and embodiments.

Figure 1 is a front elevational view of a first embodiment of the present invention;

Figure 2 is a perspective view of one direction of the feed replacement chamber of the present invention;

Figure 3 is a perspective view showing the other direction of the feed replacement tank of the present invention;

Figure 4 is a front elevational view of a second embodiment of the present invention.

detailed description

The concept, the specific structure and the technical effects of the present invention will be clearly and completely described in conjunction with the embodiments and the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

It should be noted that, unless otherwise stated, when a feature is referred to as “fixed” or “connected” in another feature, it may be directly fixed, connected to another feature, or indirectly fixed and connected to another feature. A feature. Further, the descriptions of the upper, lower, left, right, front, rear, and the like used in the present invention are merely relative to the mutual positional relationship of the respective components of the present invention in the drawings.

Moreover, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, unless otherwise defined. The terminology used in the description herein is for the purpose of description The term "and/or" used herein includes any combination of one or more of the associated listed items.

Referring to Figure 1, a front view of a first embodiment of the present invention is shown. As shown in the figure, the vacuum sintering furnace comprises a furnace body 100, a feed replacement tank 200 and a discharge replacement tank 300, wherein the furnace body 100 serves as a main place for material sintering, and the feed replacement tank 200 and the discharge replacement tank 300 are respectively used for Before the material is fed and before the discharge, the furnace 100 can be used for continuous production of the vacuum sintering furnace.

The furnace body 100 can be a well-known vacuum sintering furnace body structure, which is not limited in the present invention. Preferably, the furnace body 100 is provided with a heating zone and a cooling zone in the direction of the feed replacement compartment 200 to the discharge replacement compartment 300, so that the material can be heated and then cooled. Further, the heating zone preferably has a plurality of sections of different temperatures, and the furnace body of the cooling zone is preferably provided with a water-cooled interlayer to achieve rapid heat dissipation through the water-cooled interlayer.

Specifically, referring to FIG. 2 and FIG. 3, respectively, three-dimensional schematic diagrams of different directions of the feed replacement tank of the present invention are shown, wherein the first hatch is in a closed state and the second hatch is in an open state. As shown, the feed replacement chamber includes a cabin 210 having a first hatch 220 leading to the outside and a second hatch 230 leading to the furnace body 100, the first hatch 220 and the second The hatch 230 can Independently opening and closing, and after the first hatch 220 and the second hatch 230 are completely closed, a sealed space is formed in the cabin 210, and a vacuum environment can be formed in the cabin 210 in conjunction with the vacuuming device.

Preferably, the cabin 210 is further provided with an intake valve.

The door can be any known door structure. In this embodiment, a hanging door structure is preferably used. Taking the second door 230 as an example, the bracket 231 is fixed on the cabin 210. The straight guide rail 232 is slidably connected to the guide rail 232, and the top end of the door leaf 233 is fixed to the drive shaft of the cylinder 234. When the door leaf 233 is moved to the lower end of the bracket 231, the opening on the cabin 210 is blocked; when the door leaf 233 When moving to the upper end of the bracket 231 as shown in the figure, the opening is opened, and the internal space of the cabin 210 communicates with the internal space of the furnace body 100.

The present invention preferably also includes a first material transfer device 410 for feeding material from the feed displacement chamber 200 to the furnace body 100. The first material transfer device 410 in this embodiment preferably adopts a push rod mechanism, as shown in FIG. 3, and includes a power device 411 fixedly connected to the cabin 210, such as a cylinder, a motor, etc., and a second door 230. The push rod 412, the push rod 412 can be moved toward the second hatch 230 by the power unit 411, and can be reset by the spring 413.

Corresponding to the above-mentioned push rod mechanism, referring to FIG. 2, the inside of the cabin 210 is further provided with a slide rail including a slide rail 211 facing the second hatch 230 and a slide rail facing the first hatch 220 (not shown) Out). The material is preferably placed on the carrier 700, the carrier can be moved relative to the slide rail, and the stroke of the push rod 412 should be greater than the length of the cabin 210.

Referring to Fig. 1, the structure of the discharge replacement tank 300 is similar to that of the feed replacement tank 200, that is, includes a tank 310 having a third hatch 320 leading to the outside and a passage to the furnace body 100. The fourth hatch 330. The material discharge device 300 is also provided with a material transfer device, that is, a fourth material transfer device 440, with the difference that the fourth material transfer device 440 is used to feed the material from the discharge replacement chamber 300.

In order to realize the movement of the material in the furnace body 100, the furnace body 100 is provided with a second material transfer device 420 for pushing the material to move in the furnace body 100, and the material is sent from the furnace body 100 to the discharge replacement chamber 300. The structure of the third material transfer device 430, the second material transfer device 420, and the third material transfer device 430 is similar to that of the first material transfer device 410, and will not be described herein.

The first hatch 220 and/or the second hatch 230 should be in a closed state with the third hatch 320 and/or the fourth hatch 330, ie, at least one of the first hatch 220 and the second hatch 230, At least one of the third hatch 320 and the fourth hatch 330 should be simultaneously closed to ensure that the furnace body 100 is maintained in a vacuum during operation. Specifically referring to FIG. 1 , FIG. 2 and FIG. 3 , the usage method of the present invention is:

1. First start the equipment, each door is closed, open the furnace vacuum pump 510 to vacuum to the set value (the furnace vacuum pump is always turned on during the operation of the equipment to maintain the set vacuum), and turn on the furnace heating device to the set temperature.

2. The first hatch 220 and the second hatch 230 of the feed replacement tank 200 are in a closed state at this time, and it is checked whether the air pressure value in the cabin 210 is consistent with the ambient air pressure, and if not, the air intake on the cabin 210 is opened. The valve keeps the pressure constant.

3. When the air pressure in the cabin 210 coincides with the ambient air pressure, the first hatch 220 is opened (the second hatch 230 remains closed at this time), and the carrier on which the material is placed is sent to the cabin 210.

4. After the material is delivered into the cabin 210, the first hatch 220 is closed, and the inlet vacuum pump 520 is activated to evacuate the cabin 210 to a set value.

5. After the vacuum in the cabin 210 has reached the set value, check whether the second material transfer device 420 is in the initial position. If the second material transfer device 420 is not in the initial position, wait for the second material transfer device 420 to complete the push action. Go back to the initial position.

6. When the degree of vacuum in the cabin 210 has reached the set value and the second material transfer device 420 is in the initial position, the second hatch 230 is opened (the first hatch 220 remains closed at this time), and the first material transfer is started. The device 410 pushes the carrier within the pod 210 to a loading position within the furnace body 100.

7. After the carrier arrives at the cabin 210, the first material transfer device 410 is retracted and reset, the second door 230 is closed, nitrogen gas is introduced into the cabin 210 or the intake valve is opened, so that the air pressure in the cabin 210 and the external environment are Consistent.

8. Check whether the third material transfer device 430 is in the initial position (back limit). If not, wait for the third material transfer device 430 to complete the operation and return to the initial position; if yes, start the second material transfer device 420 to push the feed. At the position of the carrier, the pushing stroke of the second material transfer device 420 is slightly larger than the length of the single carrier, so that the sequentially arranged carriers in the furnace body can be moved integrally in the direction of the discharge replacement chamber 300.

9. When the carrier at the end of the furnace body 100 is aligned with the third material transfer device 430, the second material transfer device 420 is reset; at this time, it is checked whether the discharge replacement chamber 300 is empty, and if it is not empty, it is waiting for discharge replacement. If the discharge replacement chamber 300 is empty, it is checked whether the vacuum degree reaches the set value. If the set value is not reached, the outlet vacuum pump 530 is started to evacuate to the set value, for example, the discharge replacement chamber 300 is empty. And the set vacuum is reached, the outlet vacuum pump 530 is closed and the fourth hatch 330 is opened (at this time the third hatch 320 remains closed).

10. When the fourth hatch 330 is opened, the third material transfer device 430 initiates pushing the carrier at the end of the furnace body 100 to the discharge replacement chamber 300.

11. When the carrier reaches the discharge replacement chamber 300, the third material transfer device 430 is reset and the fourth door 330 is closed.

12. When the fourth hatch 330 is closed, the intake valve of the discharge replacement chamber 300 is opened to make the air pressure in the discharge replacement chamber 300 coincide with the ambient air pressure.

13. When the air pressure in the discharge replacement chamber 300 coincides with the ambient air pressure, the third hatch 320 is opened (the fourth hatch 330 remains closed), and the fourth material transfer device 440 is started after the third hatch 320 is opened. The carrier is delivered from the discharge replacement compartment 300.

14. When the carrier is delivered, the third hatch 320 is closed.

Thus, the above steps 2 to 14 can be repeated to achieve continuous sintering of the material. Since the furnace body can be continuously maintained in a heating and vacuum state, the process of frequently evacuating, heating, holding, and cooling the inside of the furnace body is eliminated, thereby The earth enhances production efficiency and is more suitable for large-scale production. At the same time, the vacuum sintering furnace does not need to frequently raise and lower temperature, thereby saving energy and prolonging the service life of the vacuum furnace; in addition, heat conduction can only be achieved by radiation and heat conduction during vacuum sintering. The internal temperature rise rate is slower, and the existing vacuum sintering furnace has to increase the furnace volume in order to pursue greater production capacity, so the temperature uniformity of the heating temperature zone in the furnace cavity is poor (usually the temperature difference is about ±10 °C), thus affecting Sintering of the material.

Referring to Figure 4, a front elevational view of a second embodiment of the present invention is shown. As shown in the figure, in this embodiment, a return line is added on the basis of the first embodiment, and the return line is connected to the feed replacement chamber 200 and the discharge replacement chamber 300, so that the return of the carrier can be realized, thereby further improving the production efficiency. . Preferably, the return line includes a first return line 610 connected to the feed replacement chamber 200, a second return line 620 connected to the discharge replacement chamber 300, and a first return line 610 and a second return line 620. The third return line 630.

In order to realize the movement of the carrier on each return line, the embodiment is further provided with a fifth material transfer device 450 for transporting the material from the third return line 630 to the first return line 610, and the material is returned by the first return. Line 610 is transported to sixth material transfer device 460 of feed replacement chamber 200, which carries material from second return line 620 to seventh material transfer unit 470 of third return line 630, and pushes the material at a third reflow. The eighth material transfer device 480, the fifth material transfer device 450, the sixth material transfer device 460, the seventh material transfer device 470, and the eighth material transfer device 480, which are moved on the line 630, have a structure similar to that of the first material transfer device 410. Do not repeat here.

The embodiment further adds a reflow step to the steps of the first embodiment, including:

1. The fourth material transfer device 440 transports the carrier from the discharge replacement chamber 300 to the second return line 620.

2. The seventh material transfer device 470 resets the carrier after being transported by the second return line 620 to the third return line 630.

3. The eighth material transfer device 480 pushes the carrier to move on the third return line 630, and moves to the set position and then resets.

4. The fifth material transfer device 450 resets the carrier after being transported by the third return line 630 to the first return line 610.

5. The sixth material transfer device 460 resets the carrier after being transported by the first return line 610 to the feed replacement chamber 200.

The above is a detailed description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments, and various equivalent modifications or substitutions can be made by those skilled in the art without departing from the spirit of the invention. Such equivalent modifications or alternatives are intended to be included within the scope of the claims.

Claims

A vacuum sintering furnace capable of achieving continuous production, comprising: a furnace body, a feed replacement tank and a discharge replacement tank, the feed replacement tank comprising a first hatch leading to the outside and a furnace door a second hatch of the body, the discharge replacement compartment comprising a third hatch leading to the outside and a fourth hatch leading to the furnace body, the first hatch, the second hatch, the third cabin The door and the fourth hatch can be independently opened and closed, wherein the first hatch and/or the second hatch are simultaneously closed with the third hatch and/or the fourth hatch to ensure the The internal space of the furnace body maintains a vacuum during operation.
A vacuum sintering furnace capable of achieving continuous production according to claim 1, further comprising a first material transfer device for feeding material from said feed displacement chamber to said furnace body.
A vacuum sintering furnace capable of achieving continuous production according to claim 1, further comprising a second material transfer device that pushes the material to move within the furnace body.
A vacuum sintering furnace capable of achieving continuous production according to claim 1, further comprising a third material transfer device for feeding material from said furnace body to said discharge replacement chamber.
A vacuum sintering furnace capable of achieving continuous production according to claim 1, further comprising a fourth material transfer device for discharging material from said discharge discharge chamber.
A vacuum sintering furnace capable of achieving continuous production according to any one of claims 1 to 5, further comprising a return line connecting the feed replacement chamber and the discharge replacement chamber.
A vacuum sintering furnace capable of achieving continuous production according to claim 6, wherein said return line comprises a first return line connecting said feed replacement chamber, and a second connection connecting said discharge replacement tank a return line, and a third return line connecting the first return line and the second return line.
A vacuum sintering furnace capable of achieving continuous production according to claim 7, further comprising: a fifth material transfer device for conveying material from said third return line to said first return line, said material a sixth material transfer device transported by the first return line to the feed replacement chamber, a material transported by the second return line to a seventh material transfer device of the third return line, and An eighth material transfer device that pushes the material to move on the third return line.
A vacuum sintering furnace capable of achieving continuous production according to claim 6, further comprising a plurality of carriers sequentially arranged on said return line and movable relative to said return line.
The vacuum sintering furnace capable of achieving continuous production according to any one of claims 1 to 5, wherein the furnace body is sequentially heated in the direction from the feed replacement chamber to the discharge replacement chamber. Zone and cooling zone.