JP2002167607A - Electric pressure sintering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric pressure sintering apparatus which can be automated, improve the efficiency in the case of manufacturing sintered stocks, and realize mass production. SOLUTION: This electric pressure sintering apparatus 1 having a pair of sintering shafts for performing the electric pressure sintering of a sintering die 80 with the powder m to be sintered in the vertical direction and a vacuum chamber 2 for sealing the sintering die 80 comprises a spare chamber 202 provided adjacent to the vacuum chamber 2, an evacuating means for evacuating the spare chamber 202, an inner gate valve 205 provided in an opening/closing manner between the spare chamber 202 and the vacuum chamber 2, a between- chamber moving means for taking in/taking out the sintering die 80 between the vacuum chamber 2 and the spare chamber 202 when the inner gate valve 205 is opened, an outer gate valve 208 provided in an opening/closing manner at an appropriate location of the spare chamber 202, and a carrying-in/carrying- out means 219 for carrying the sintering die 80 in/out of the spare chamber 202 when the outer gate valve 208 is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric pressure sintering apparatus. More specifically, energization is performed while applying pressure to a sintering mold in which powder to be sintered such as metal or ceramics is placed, and the energization causes the sintering mold to generate heat and sinter the powder to be sintered. Related to the device.

[0002]

2. Description of the Related Art FIG. 8 is a schematic explanatory view of a conventional electric pressure sintering apparatus. As shown in the figure, the conventional electric pressure sintering apparatus 101 has a tunnel-like structure, and is electrically pressurized by a mold loading gate 201 and a mold unloading gate 204 provided at the entrance and the exit thereof so as to be openable and closable. The inside of the sintering apparatus 101 is hermetically sealed from the outside. Also, the mold loading gates 201 and 2
The space between 04 is divided into three spaces by a sintering chamber entrance gate 202 and a cooling chamber entrance gate 203. Each space includes a preheating chamber 130, a sintering chamber 120, and a cooling chamber 140 in order from the mold loading gate 201.

A preheating chamber 130 is a space for preheating the powder m to be sintered. The sintering chamber 120 is a space for sintering the preheated powder m to be sintered. The cooling chamber 140 is a space for cooling the sintered powder m to be sintered.

A preheating chamber 130, a sintering chamber 120 and a cooling chamber 140
Are provided with roller tables 210 to 213 for carrying the sintering die 80 thereon. On the roller tables 210 to 213, a plurality of cylindrical rollers are horizontally arranged. For this reason, the sintering mold 80 is
If the rollers are rolled while placed on rollers 210 to 213, the sintering mold 80 moves on the rollers. Therefore, the sintering mold 80 is moved by the roller tables 210 to 213 to the preheating chamber 130.
→ Sintering chamber 120 → Cooling chamber 140

Next, an operation of continuously sintering a plurality of powders m to be sintered by a conventional electric pressure sintering apparatus will be described. As shown in FIG. 8, in the case of continuously sintering the powder m to be sintered, in order to shorten the cycle time of sintering, the preheating chamber 130, the sintering chamber 120 and the cooling chamber 140 are sintered. Each of the molds 80 is housed, and preheating, sintering, and cooling operations are performed simultaneously. At this time, each chamber is kept in a vacuum.

When all the operations are completed, first, the cooling chamber 14
0 to the atmospheric pressure, open the mold discharge gate 204 and open the cooling chamber
From 140, the sintering mold 80 is unloaded by hand.

Next, the mold discharge gate 204 is closed and the cooling chamber is closed.
140 is evacuated (first time), the cooling chamber entrance gate 203 is opened, and the sintering chamber 120 is opened by the roller tables 212 and 213.
Then, the sintering mold 80 is transferred to the cooling chamber 140, and the cooling chamber entrance gate 203 is closed.

Next, the sintering chamber entrance gate 202 is opened, the sintering mold 80 is transported from the preheating chamber 130 to the sintering chamber 120 by the roller table 211, and the sintering chamber entrance gate 202 is closed.

Next, the interior of the preheating chamber 130 is set to the atmospheric pressure, the mold loading gate 201 is opened, and the sintered mold 80 is placed in the preheating chamber 130.
The mold is loaded by hand, and the mold loading gate 201 is closed. Finally, if the inside of the preheating chamber 130 is evacuated (second time), the loading of the new sintering mold 80 is completed.

When the loading of the new sintering mold 80 is completed, the preheating chamber 130, the cooling chamber 140, and the sintering chamber 120 perform preheating,
Sintering and cooling work are performed simultaneously.

By repeating the above operation, a sintered product can be manufactured continuously.

[0012]

However, the sintering mold 80
Is a roller table from the preheating chamber 130 to the cooling chamber 140
The sintering die 80 is automatically transferred from the outside to the preheating chamber 130, and the sintering die 80 is transferred from the cooling chamber 140 to the outside by manual operation. However, there is a problem that it takes time and effort. Also, since the cooling time of the sintering mold 80 usually requires 5 to 6 times the sintering time, even if the work of sintering and residual heat is completed, a new sintering mold is required until the cooling work is completed. 80 cannot be carried in. There is a problem that the efficiency of manufacturing a sintered product is low.

In view of such circumstances, the present invention can be automated, and can improve the efficiency of producing a sintered product.
It is an object of the present invention to provide an electric pressure sintering apparatus that can be mass-produced.

[0014]

According to a first aspect of the present invention, there is provided an electric current pressure sintering apparatus comprising: a pair of sintering shafts for vertically sintering a sintering mold containing powder to be sintered; What is claimed is: 1. A current-pressing and sintering apparatus comprising a vacuum chamber in which a sintering mold is sealed and kept in a vacuum, comprising: a preliminary chamber provided adjacent to said vacuum chamber; and a vacuum in said preliminary chamber. A vacuum evacuation means, an inner gate valve provided to be openable and closable between the preliminary chamber and the vacuum chamber, and the firing between the vacuum chamber and the preliminary chamber when the inner gate valve is opened. Inter-chamber moving means for taking the mold in and out, an outer gate valve provided to be openable and closable at an appropriate position in the spare chamber, and a sintering mold carried into and out of the spare chamber when the outer gate valve is opened. It is characterized by comprising a loading and unloading means That. According to a second aspect of the present invention, in the first aspect of the present invention, the rotary sintering apparatus is provided so as to be rotatable in a horizontal plane in the vacuum chamber, and a peripheral portion passes between the pair of sintering shafts. A table, provided at a plurality of locations along the periphery of the rotary table,
And a mold holding portion for holding a sintering mold sandwiched between the pair of sintering shafts, wherein the preliminary chamber is provided behind the sintering shaft in the rotation direction of the rotary table. Features. According to a third aspect of the present invention, the sintering mold is placed on a tray to constitute a sintering mold unit.
A catch portion is formed on the tray, a sintering hole into which a sintering shaft can be inserted is formed at the bottom, and the inter-chamber moving means is a telescopic cylinder. It is characterized by comprising a detachable portion capable of attaching and detaching the hook portion of the tray. According to a fourth aspect of the present invention, the sintering die is placed on a tray to form a sintering die unit. A carry-in conveyor for carrying in the sintering mold unit, a carry-in cylinder for pushing the sintering mold on the carry-in conveyor from the outer gate valve into the preliminary chamber, and carrying out the sintering mold unit to the next step. And a discharge cylinder for extruding the sintering unit in the preliminary chamber from the outer gate valve onto the discharge conveyor.

According to the first aspect of the present invention, after the inside of the preparatory chamber is evacuated by the evacuation means in a state where the inside of the vacuum chamber is kept at a vacuum and the outer gate valve and the inner gate valve are both closed. Open only the inside gate valve.
Then, communication between the vacuum chamber and the preliminary chamber can be made while maintaining the vacuum in the vacuum chamber, and the sintering mold is bidirectionally moved between the vacuum chamber and the preliminary chamber by the inter-chamber moving means. You can move. Further, with both the vacuum chamber and the spare chamber kept in vacuum, the inner gate valve is closed and then the outer gate valve is opened. Then, only the preliminary chamber can be opened to the outside while the vacuum chamber is kept in a vacuum, and the sintering mold can be carried into and out of the preliminary chamber by the carrying-in / out means. Therefore, sintering from delivery of the sintering mold,
The work up to carrying out can be automated. According to the second aspect of the present invention, by rotating the rotary table while holding the sintering mold on the mold holding unit, each sintering mold can be sequentially positioned between the pair of sintering shafts. Therefore, the sintering mold can be sequentially sintered by the pair of sintering shafts. In addition, the sintering mold after the sintering process is moved to the position of the inner gate by rotation of the rotary table while the subsequent sintering dies are sequentially sintered to the sintering mold, and is moved to the mold holding portion. It is gradually cooled while being held. Therefore, while one sintering mold is being cooled, another sintering mold can be sintered, so that the efficiency of manufacturing a sintered product can be improved, and the productivity can be improved.
Mass production is possible. According to the third aspect of the present invention, the sintering unit can be mounted in the vacuum chamber simply by attaching and detaching the attachment / detachment portion provided at the tip of the rod of the cylinder for moving between chambers to the hook of the tray and extending and contracting the cylinder. It can be moved bidirectionally between and the reserve chamber. Therefore, the mechanism for taking the sintered mold unit in and out of the vacuum chamber can be simply configured. Further, since a sintering hole into which the sintering shaft can be inserted is formed at the bottom of the tray, even if the sintering die is placed on the mold holding portion of the rotary table while being placed on the tray, the sintering shaft is used for sintering. The mold can be pressure sintered. According to the fourth aspect of the present invention, the sintering unit can be pushed into the spare chamber from the carry-in conveyor simply by extending the carry-in cylinder. Further, the sintering unit can be pushed out of the preliminary chamber to the carry-out conveyor simply by extending the carry-out cylinder. Furthermore, when both the carry-in conveyor and the carry-out conveyor are driven in only one direction, the carry-in and carry-out of the sintering unit can be performed. Therefore, the mechanism for loading and unloading the sintering unit into and from the preliminary chamber can be easily configured. Only the drive needs to be controlled, and the control is simple.

[0016]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional explanatory view of an electric pressure sintering apparatus 1 of the present embodiment. FIG. 2 is a sectional view taken along line A-0-A of FIG. As shown in FIG. 1 and FIG. 2, the current-pressure sintering apparatus 1 of the present embodiment includes a And a sintering unit loading / unloading unit 200 for loading / unloading the sintering die 80 to / from the sintering cooling unit 10.

First, before explaining the sintering cooling section 10 and the sintering mold unit loading / unloading section 200, the sintering mold 80 moved between them will be described. The sintering mold 80 includes a mold 81 and a pair of upper and lower dies 82 and 83. The mold 81 is formed in a cylindrical shape having a hollow portion. Each of the dies 82 and 83 is formed in a columnar shape having the same diameter as the hollow portion of the mold 81. Therefore, copper (Cu), nickel (Ni),
The powder m to be sintered such as alumina (Al ₂ O ₃ ) can be stored in an airtight manner.

The sintering mold 80 is placed on a tray 85. The tray 85 has a horizontal bottom portion 86 on which the sintering die 80 is placed, and a hook portion 89 formed in a protruding shape at one end of the bottom portion 86, and has an L-shape in side view. The bottom portion 86 is formed with a sintering hole 87 penetrating the upper surface and the lower surface. The sintering hole 87 is formed such that its inner diameter is larger than the outer shape of the die 83 and the lower pressurizing electrode shaft 27 of the sintering die 80 and smaller than the outer shape of the mold 81. Also, at the upper end of the sintering hole 87,
A holding seat 88 that is circularly recessed from the upper surface of the bottom 86 is provided. Therefore, the die 83 of the sintering die 80 is inserted into the sintering hole 87 of the tray 85, and the mold 81 is inserted into the holding seat 88.
Is placed on the tray 85, the sintering mold 80 is held by the tray 85. Thus, the sintering mold 80 is placed on the tray 85 to constitute the sintering mold unit 75. Details of the hook 89 will be described later.

Now, the sintering cooling section 10 will be described. The sintering cooling unit 10 basically includes a vacuum chamber 2, a sintering unit 20, and a rotary table 5.

First, the sintering section 20 will be described. As shown in FIG. 1, the sintered portion 20 has a substantially U-shape in side view, and includes a pair of upper and lower bases 21a and 21b. On the upper surface of the lower base 21b, a hydraulic cylinder 29 is provided with its piston rod vertically upward.

On the lower surface of the upper base 21a, the upper end of an upper pressure electrode shaft 26 is fixed vertically downward. Below the upper pressurizing electrode shaft 26, the center of the shaft is aligned,
The lower pressure electrode shaft 27 is provided vertically upward. The lower end of the lower pressure electrode shaft 27 is attached to a piston rod of the hydraulic cylinder 29. For this reason, the lower pressure electrode shaft 27 is moved by the hydraulic cylinder 29 to the lower base 2.
1b, it can move up and down freely. Therefore, the lower pressure electrode shaft 2 is
If 7 is raised, it is possible to press the sintering mold 80 between the pair of upper and lower pressing electrode shafts 26 and 27 and pressurize the shaft.

The material of the pair of upper and lower pressurizing electrode shafts 26 and 27 may be any material having electric conductivity and high strength, such as graphite and tungsten carbide. Therefore, a pair of upper and lower pressing electrode shafts 26, 2
If a positive electrode and a negative electrode of a DC power supply (not shown) are connected to the power supply 7, current can flow between the pair of upper and lower pressure electrode shafts 26 and 27. The pair of upper pressure electrode shafts 26 and lower pressure electrode shafts 27 are a pair of upper and lower sintered shafts described in the claims.

Therefore, according to the sintering section 20, the sintering mold 80 can be energized by the pair of upper and lower pressing electrode shafts 26 and 27.

Next, the vacuum chamber 2 will be described. FIG.
As shown in FIG. 2, a vacuum chamber 2 is provided between the pair of upper and lower bases 21a and 21b of the sintering section 20. The vacuum chamber 2 is an airtight closed container having a cylindrical shape. The pair of upper and lower pressure electrode shafts 26 and 27 penetrate the upper plate 2b and the lower plate 2c of the vacuum chamber 2, respectively. The upper plate 2b and the lower plate 2c are air-tightly and slidably attached to the outer periphery of a pair of upper and lower pressure electrode shafts 26 and 27, respectively. A rotating shaft 6, which will be described later, penetrates through the lower plate 2c, and is attached in an airtight and rotatable manner. Side wall 2 of this vacuum chamber 2
a has a loading port 2p for loading and unloading the sintered mold 80;
Is formed, and is communicated with the preliminary chamber 202 described later by the carry-in port 2p.

The vacuum chamber 2 is connected to a vacuum pump (not shown). Therefore, if the inside of the vacuum chamber 2 is evacuated by the vacuum pump,
Can be kept in a vacuum.

Next, the support structure of the rotary table 5 will be described. As shown in FIG. 1, a bearing 7 is fixed to a machine frame (not shown). The rotating shaft 6 is rotatably attached to the bearing 7 with the rotating shaft 6 standing upright. As described above, the rotating shaft 6 penetrates through the lower plate 2c of the vacuum chamber 2 and is airtightly and rotatably mounted.
A gear is attached to the lower end of the rotating shaft 6,
This gear meshes with a gear attached to the main shaft of the motor M.

A rotary table 5 on a disk is attached to the upper end of the rotary shaft 6 at the center of the lower surface.
The rotary table 5 is provided horizontally, and its peripheral portion is provided between the pair of upper and lower pressing electrode shafts 26 and 27. A plurality of mold holding portions 60 for holding the sintering mold unit 75 are provided at a plurality of positions on the peripheral portion of the rotary table 5, which will be described later in detail.

For this reason, if a plurality of sintering die units 75 are held by the die holding part 60 at the periphery of the rotary table 5 and the rotary table 5 is rotated, the sintering die units 75 are sequentially fired. The forming unit 75 can be located between the pair of upper and lower pressing electrode shafts 26 and 27.

As described above, according to the sintering cooling unit 10,
In the vacuum chamber 2 maintained in a vacuum, the rotary mold 5 can sequentially position the sintering mold unit 75 between the pair of upper and lower pressing electrode shafts 26 and 27 by the rotary table 5. 27 allows the sintering mold 80 to be sequentially sintered under pressure.

The electric pressure sintering apparatus 1 of this embodiment is characterized in that a sintering unit loading / unloading section 200 for loading / unloading the sintering unit 75 into / from the vacuum chamber 2 is provided. Therefore, the sintering unit loading / unloading section 200 will be described. The sintering unit loading / unloading section 200 includes a preliminary chamber 202, an inner gate valve 205, an outer gate valve 208, and a cylinder for moving between chambers.
And a loading / unloading means 219.

First, the spare chamber 202 will be described. In the vacuum chamber 2, the rotation direction of the rotary table 5 behind the upper and lower pressure electrode shafts 26 and 27 is provided.
A spare chamber 202 is provided adjacent to the outer surface of the vacuum chamber 2. This spare chamber 202
It is a box-shaped member. A carry-in port 2p is formed between the preliminary chamber 202 and the vacuum chamber 2 to communicate the two. The preliminary chamber 202 is connected to a vacuum pumping means (not shown) for vacuuming, such as a vacuum pump, but the vacuuming means for vacuuming is not limited to a vacuum pump.

Next, the inner gate valve 205 will be described. An inner gate valve 205 is provided at the entrance 2p so as to be freely opened and closed. Opening and closing the inner gate valve 205 allows communication between the vacuum chamber 2 and the spare chamber 202,
It can be shut off airtight.

Next, the cylinder 211 for moving between chambers will be described. In the spare chamber 202, an inter-chamber moving cylinder is provided on a side surface facing the inner gate valve 205.
211 is mounted horizontally with the end of the rod facing the inner gate valve 205. The cylinder 211 for moving between chambers is a means for moving between chambers described in the claims. The cylinder for movement between chambers 211 may be a known hydraulic cylinder. This cylinder 211 for moving between chambers
The tip of the rod is inserted into the spare chamber 202, and its cylinder body is airtightly fixed to the side of the spare chamber 202.

At the tip of the rod of the cylinder 211 for moving between chambers, there is provided an attaching / detaching portion 215 to which the hook 89 of the tray 85 can be attached / detached. The attachment / detachment portion 215 is a pair of front and rear long rectangular plates, and the front plate is rotatably provided. When the front plate becomes vertical, the hook 89 can be engaged between the front and rear plates. The hook 89 can be detached when the front plate is turned sideways. The structure of the detachable portion 215 is not limited to the above structure as long as the hook portion 89 can be detached.

For this reason, if the attaching / detaching portion 215 is attached to the hook portion 89 of the tray 85 and the cylinder 211 for inter-chamber movement is extended and contracted with the inner gate valve 205 opened, the inner gate valve 205 The sintering unit 75 can be moved in both directions between the preliminary chamber 202 and the rotary table 5 in the vacuum chamber 2.

Next, the outer gate valve 208 will be described. In the spare chamber 202, an outer gate valve 208 is provided on the right side surface in FIG. By opening and closing the outer gate valve 208, the inside of the preparatory chamber 202 can be opened to the outside or hermetically shut off from the outside.

Next, the loading / unloading means 219 will be described. The carry-in / out means 219 includes a carry-out cylinder 230 and a carry-out conveyor 24.
5. It is composed of a carry-in conveyor 240 and a carry-out cylinder 230. This loading cylinder 220 and unloading cylinder
230 is a known cylinder, and the carry-out conveyor 245 and the carry-in conveyor 240 are well-known conveyors, and is characterized in that the sintering unit 75 is automatically loaded and unloaded in the spare chamber 202. .

First, the unloading cylinder 230 will be described. In the preparatory chamber 202, a discharge cylinder 230 is mounted horizontally on the side opposite to the outer gate valve 208 with the end of the rod facing the outer gate valve 208. In the unloading cylinder 230, the tip of the rod is
2, the cylinder body of which is hermetically fixed to the side surface of the spare chamber 202. At the end of the rod of the unloading cylinder 230, an extruded plate 23
1 is installed. Therefore, the outer gate valve 208
Is opened and the carry-out cylinder 230 is extended,
Since the sintering mold unit 75 can be pushed by 1, the sintering mold unit 75 can be moved onto the unloading conveyor 245 through the outer gate valve 208.

Next, the unloading conveyor 245 will be described. On the side of the outer gate valve 208, a carry-out conveyor 245 is arranged in parallel with the cylinder 211 for moving between chambers.
The unloading conveyor 245 is for unloading the sintered mold unit 75 extruded from the vacuum chamber 2 to the next step. The unloading conveyor 245 is driven only in one direction from the spare chamber 202 side toward the next process.

Next, the carry-in conveyor 240 will be described. On the side of the carry-out conveyor 245, a carry-in conveyor 240 is provided in parallel with the carry-out conveyor 245. This loading conveyor
240 can be operated intermittently by, for example, a stepping motor. Therefore, if the sintering unit 75 is placed on the carry-in conveyor 240, the sintering unit 75 can be stopped at a desired position. Further, the carry-in conveyor 240 is driven only in one direction from the previous process toward the preparatory chamber 202.

Next, the carry-in cylinder 220 will be described. On the side of the carry-in conveyor 240, on the side opposite to the spare chamber 202 with respect to the carry-in conveyor 240, a carry-in cylinder 220 is provided.
Is provided. The carry-in cylinder 220 has its rod end disposed horizontally toward the outer gate valve 208. A push plate 221 which is a flat plate is attached to the tip of the rod of the carry-in cylinder 220. Therefore, when the outer gate valve 208 is opened and the carry-in cylinder 220 is extended, the sintering unit 75 on the carry-in conveyor 240 can be pushed by the pushing plate 221.
5 can be moved into the pre-chamber 202 through the inner gate valve 205.

Therefore, according to the carrying-in / out means 219, the sintering mold unit 75 can be moved from the carrying-in conveyor 240 into the spare chamber 202 only by extending the carrying-in cylinder 220. Further, the sintering unit 75 can be moved from the preliminary chamber 202 to the unloading conveyor 245 only by extending the unloading cylinder 230. Furthermore, when the carry-in conveyor 240 and the carry-out conveyor 245 are both driven in only one direction, the carry-in and carry-out of the sintering unit 75 can be performed. Therefore, the spare chamber
The mechanism for loading and unloading the sintering unit 75 in 202 can be simplified, and the timing for loading and unloading can be controlled by controlling only the expansion and contraction of the loading and unloading cylinders 220 and 230 and the drive of the loading conveyor 240. Easy.

As described above, the sintering unit loading / unloading section 20
According to 0, the inside of the preliminary chamber 202 was evacuated by vacuuming means such as a vacuum pump in a state where the inside of the vacuum chamber 2 was kept at a vacuum and both the outer gate valve 208 and the inner gate valve 205 were closed. Thereafter, only the inner gate valve 205 is opened. Then, the vacuum chamber 2 and the spare chamber 202 can be communicated with each other while the vacuum chamber 2 is kept in a vacuum.
The sintered mold unit 75 can be moved in both directions between the vacuum chamber 2 and the preparatory chamber 202. Further, with both the vacuum chamber 2 and the spare chamber 202 kept in vacuum, the inner gate valve 205 is closed and then the outer gate valve 208 is closed.
Is opened. Then, only the preparatory chamber 202 can be opened to the outside while the vacuum chamber 2 is kept in a vacuum, and the sintering unit 75 can be carried in and out of the preparatory chamber 202 by the carrying in / out means 219. .
Therefore, the operations from loading of the sintering unit 75 to sintering and unloading can be automated.

Next, the mold holding section 60 will be described. A mold holding unit 60 is provided at a peripheral portion of the rotary table 5. A plurality of mold holding portions 60 are provided along the peripheral edge of the rotary table 5 at, for example, equal angular intervals. For this reason, when the motor M is driven, the rotary shaft 6 rotates and the rotary table 5 rotates in a horizontal plane, so that each mold holding portion 60 of the rotary table 5 is moved by the pair of upper and lower pressing electrode shafts 26 and 27. It passes between the two. Note that the mold holding units 60 need not be provided at equal angular intervals, but if they are provided at equal angular intervals, the rotation of the rotary table 5 can be easily controlled.

The mold holding section 60 is provided with the rotary table 5.
On the upper surface of the rotary table 5, a groove-shaped tray mounting groove 63 formed radially with respect to the center of the rotary table 5 is provided. The width of the tray mounting groove 63 is formed slightly wider than the width of the tray 85 of the sintered mold unit 75. Therefore, when the tray 85 of the sintered mold unit 75 is inserted into the tray mounting groove 63 of the mold holding section 60, the mold holding section 6
0 holds the sintered mold unit 75.

A through hole 61 penetrating between the bottom surface of the tray mounting groove 63 and the lower surface of the rotary table 5 is provided.
Are formed. The inner diameter of the through hole 61 is larger than the outer diameter of the lower pressure electrode shaft 27 of the sintered portion 20. Therefore, when the lower pressure electrode shaft 27 is raised and enters the through hole 61, the upper end of the lower pressure electrode shaft 27 can be brought into contact with the sintering mold 80 of the sintering mold unit 75.

Next, the current-pressure sintering apparatus 1 of this embodiment
The function and effect of will be described. FIG. 3 is a flowchart of the working process of the current-pressure sintering apparatus 1 of the present embodiment. As shown in the figure, the current-pressure sintering apparatus 1 of the present embodiment includes a first step of loading the sintering mold unit 75 into the vacuum chamber 2,
The second step of cooling the sintering mold 80 and the third step of unloading the sintering mold unit 75 from the vacuum chamber 2 are sequentially repeated, thereby continuously producing sintered products. The respective steps will be described below.

First, the mold holding section 60 of the rotary table 5
, A plurality of sintering mold units 75 are mounted. However, the sintered mold unit 75 is not mounted on the mold holding unit 60 at the position of the preliminary chamber 202. Inner gate valve 205 and outer gate valve 208 of sintering unit loading / unloading section 200
Are both closed. The inside of the vacuum chamber 2 is evacuated by a vacuum pump (not shown) and kept at a vacuum. The inside of the preliminary chamber 202 is at atmospheric pressure.

Now, the first step will be described. FIG. 4 is a flowchart of a first step of loading the sintering unit 75 into the vacuum chamber 2. FIG. 5 is a state transition diagram inside the vacuum chamber 2 and inside the preliminary chamber 202 in the first step. As shown in FIGS. 1, 2, 4 and 5, when the carry-in conveyor 240 is intermittently driven, the sintering mold unit 75 placed on the carry-in conveyor 240 is sent to the preliminary chamber 202 side. It stops before the loading cylinder 220.

Next, the outer gate valve 208 is opened (E1). At this time, since the inner gate valve 205 is kept closed, the inside of the vacuum chamber 2 is kept at a vacuum. Next, the carry-in cylinder 220 is extended, and the sintering unit 75 is moved into the preliminary chamber 202 by the press-in plate 221 of the carry-in cylinder 220.

When the sintering unit 75 enters the preliminary chamber 202, the outer gate valve 208 is closed (E2). Next, the inside of the preliminary chamber 202 is evacuated by a vacuum pump (E3). When the inside of the preliminary chamber 202 becomes vacuum, only the inner gate valve 205 is opened (E4).
Then, communication between the vacuum chamber 2 and the spare chamber 202 can be made while maintaining the vacuum inside the vacuum chamber 2.

With the inner gate valve 205 opened, the attachment / detachment portion 215 is attached to the hook 89 of the tray 85 of the sintering unit 75 in the preliminary chamber 202, and the inter-chamber transfer cylinder 211 is extended. . Then, the inside gate valve 205
Through this, the sintered mold unit 75 can be moved from the preliminary chamber 202 to the mold holding section 60 of the rotary table 5 in the vacuum chamber 2. Finally, if the inner gate valve 205 is closed (E5), the vacuum chamber 2 and the spare chamber
202 is airtightly shut off, and the transfer of the sintering unit 75 into the vacuum chamber 2 is completed.

Next, the second step will be described. First, when the motor M is operated, the rotary table 5 rotates, and the sintering mold unit 75 of the mold holding unit 60 is moved between the pair of upper and lower pressing electrode shafts 26 and 27 of the sintering unit 20.

Then, when the lower pressurizing electrode shaft 27 is raised, the upper end of the lower pressurizing electrode shaft 27 passes through the through hole 61 of the mold holding unit 60 and is used for sintering the tray 85 of the sintering mold unit 75. The hole 86 enters. Then, the upper end of the lower pressure electrode shaft 27 hits the lower end of the die 83 of the sintering die 80, and pushes up the sintering die 80. The sintering die 80 rises while being placed on the upper end of the lower pressing electrode shaft 27, and the upper end of the die 82 hits the lower end of the upper pressing electrode shaft 26, and the sintering die 80 moves to the upper pressing electrode shaft 26. And the lower pressure electrode shaft 27.
In this state, the sintering mold 8 is further moved by the lower pressure electrode shaft 27.
The sintering die 80 can be pressure-sintered by pressing the zero die 83 upward and supplying a current between the pair of upper and lower pressure electrode shafts 26 and 27.

When the sintering is completed, the lower pressure electrode shaft 27 is lowered, and the upper end of the lower pressure electrode shaft 27 is pulled out from the sintering hole 86 of the tray 85 and the through hole 61 of the mold holding unit 60.
Then, when the motor M is operated again, the sintered mold unit 75 having completed the sintering is moved to the pair of upper and lower pressure electrode shafts 26 and 27.
At the same time, a new sintered mold unit 75 can be supplied to the pair of upper and lower pressure electrode shafts 26 and 27.

The sintered mold unit 75 subjected to the sintering process is moved to the position of the inner gate valve 205 by the rotation of the rotary table 5 while the subsequent sintered mold units 75 are sequentially sintered. And gradually cooled while being held by the mold holding unit 60. Therefore, while one sintering mold unit 75 is being cooled, another sintering mold unit 75 can be sintered, so that the efficiency of manufacturing a sintered product is improved, and the productivity is improved. Mass production is possible.

Further, since the mold holding portions 60 are provided at equal angular intervals on the periphery of the rotary table 5, a new sintering mold unit 75 is provided between the pair of upper and lower heating electrode shafts 26 and 27 of the sintering portion 20. When moved, the position of the inner gate valve 205 can also be supplied with the cooled sintered mold unit 75.

Next, the third step will be described. FIG. 6 is a flowchart of the third step of unloading the sintering unit 75 from the vacuum chamber 2. FIG. 7 Vacuum chamber 2 in the step of unloading sintered mold unit 75 from vacuum chamber 2
FIG. 6 is a state transition diagram of the inside and the inside of a spare chamber 202.
As shown in FIG. 1, FIG. 2, FIG. 6, and FIG. 7, first, the inner gate valve 205 and the outer gate valve 208 are closed, and the inside of the vacuum chamber 2 and the spare chamber 202 are kept in vacuum ( D1). From that state, the inner gate valve 20
When the valve 5 is opened, communication between the vacuum chamber 2 and the spare chamber 202 is established (D2). With the inner gate valve 205 opened, the inter-chamber transfer cylinder 211 is extended, and the attachment / detachment portion 215 is attached to the hook 89 of the tray 85 of the sintered mold unit 75 on the rotary table 5. The moving cylinder 211 is contracted. Then, the sintered mold unit 75 can be moved from the rotary table 5 of the vacuum chamber 2 into the spare chamber 202 through the inner gate valve 205 by the inter-chamber moving cylinder 211.

Next, the inner gate valve 205 is closed (D3). Then, the detachable portion 215 is removed from the hook portion 89 of the tray 85 of the sintering unit 75, and the spare chamber 202 is removed.
The inside is returned to the atmospheric pressure (D4). At this time, the inner gate valve 20
5 is closed, and the inside of the vacuum chamber 2 is kept at a vacuum because the inside of the vacuum chamber 2 and the spare chamber 202 are airtightly shut off by the inner gate valve 205.

Next, the outer gate valve 208 is opened (D5). Then, when the carry-out cylinder 230 is extended,
The extruded plate 231 allows the sintered mold unit 75 in the preliminary chamber 202 to pass through the outer gate valve 208 through the preliminary chamber 20.
2 can be moved onto a carry-out conveyor 245 provided adjacent to the conveyor 2. Then, by the unloading conveyor 245,
The sintered mold unit 75 placed on the vacuum chamber 245 can be carried out to the next step.

The sintering mold 80 can be continuously sintered by repeating the above steps 1 to 3.

As described above, according to the current-pressure sintering apparatus of the present embodiment, sintering is performed after the sintering mold unit 75 is loaded,
The operation up to carrying out can be automated, the efficiency of manufacturing a sintered product can be improved, and mass production is possible.

[0063]

According to the first aspect of the present invention, the vacuum chamber and the spare chamber can be communicated with each other while maintaining the vacuum inside the vacuum chamber. And the sintering mold can be moved in both directions. In addition, only the preliminary chamber can be opened to the outside while the vacuum chamber is kept at a vacuum, and the sintering mold can be carried into and out of the preliminary chamber by the carrying-in / out means. Therefore, the operations from the loading of the sintering die to the sintering and unloading can be automated. According to the invention of claim 2, while cooling one sintering mold,
Since other sintering molds can be sintered, the efficiency of manufacturing a sintered product can be improved, productivity can be improved, and mass production is possible. According to the third aspect of the present invention, a mechanism for taking the sintered mold unit into and out of the vacuum chamber can be simply configured. Further, even if the sintering die is placed on the die holding portion of the rotary table while being placed on the tray, the sintering die can be pressure-sintered by the sintering shaft. According to the invention of claim 4, the mechanism for loading and unloading the sintering unit into and from the preliminary chamber can be simply configured, and the timing for loading and unloading the sintering unit into and from the preliminary chamber is determined by the loading and unloading cylinder. Only the expansion and contraction and the driving of the carry-in conveyor need be controlled, and the control is simple.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional explanatory view of an electric pressure sintering apparatus 1 of the present embodiment.

FIG. 2 is a sectional view taken along line A-0-A of FIG.

FIG. 3 is a flowchart of a working process of the electric pressure sintering apparatus 1 of the present embodiment.

FIG. 4 is a flowchart of a first step of loading a sintering mold unit 75 into a vacuum chamber 2;

FIG. 5 is a state transition diagram of the inside of a vacuum chamber 2 and the inside of a spare chamber 202 in a first step.

FIG. 6 is a flowchart of a third step of unloading the sintered mold unit 75 from the vacuum chamber 2.

FIG. 7 is a state transition diagram inside a vacuum chamber 2 and inside a preliminary chamber 202 in a third step.

FIG. 8 is a schematic explanatory view of a conventional electric pressure sintering apparatus 101.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric current pressure sintering apparatus 2 Vacuum chamber 5 Rotary table 60 Type holding part 75 Sintering type unit 80 Sintering type 85 Tray 86 Bottom part 87 Sintering hole 89 Hooking part 202 Spare chamber 205 Inner gate valve 208 Outer gate valve 211 Cylinder for transfer between chambers 215 Detachable / removable part 220 Carry-in cylinder 230 Carry-out cylinder 240 Carry-in conveyor 245 Carry-out conveyor m Sintered powder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27B 5/13 C04B 35/64 E H05B 3/00 340 N

Claims (4)

[Claims] A sintering shaft for vertically sintering a sintering mold containing a powder to be sintered, and a vacuum chamber for hermetically closing the sintering mold and maintaining a vacuum. An electric pressure sintering apparatus, comprising: a preliminary chamber provided adjacent to the vacuum chamber; vacuum means for evacuating the preliminary chamber; and a vacuum chamber between the preliminary chamber and the vacuum chamber. An inner gate valve provided to be openable and closable, inter-chamber moving means for moving the sintering mold in and out between the vacuum chamber and the spare chamber when the inner gate valve is opened, and a proper position of the spare chamber And a loading / unloading means for loading / unloading the sintering mold into / from the preliminary chamber when the outer gate valve is opened. apparatus. 2. A rotary table provided in the vacuum chamber so as to be rotatable in a horizontal plane and having a peripheral portion passing between the pair of sintering shafts, and a plurality of rotary tables being provided along the peripheral portion of the rotary table. And a mold holding portion for holding a sintering mold sandwiched between the pair of sintering shafts,
The current-pressure sintering apparatus according to claim 1, wherein the preliminary chamber is provided behind the sintering shaft in a rotation direction of the rotary table. 3. The sintering die is mounted on a tray to form a sintering die unit, and the tray has a hook portion formed therein, and a sintering hole into which a sintering shaft can be inserted at a bottom portion. 2. The inter-chamber moving means is a telescopic cylinder, and has an attachment / detachment part at a tip end of a rod of the cylinder to which a hook part of the tray can be attached / detached.
Or an electric pressure sintering apparatus according to 2. 4. The sintering mold is mounted on a tray to constitute a sintering mold unit, and the carry-in / out means includes a carry-in conveyor for carrying in the sintering mold unit, and a sintering unit on the carry-in conveyor. A carry-in cylinder for pushing the sintering mold from the outer gate valve into the preliminary chamber, an unloading conveyor for carrying out the sintering mold unit to the next process, and a sintering mold unit in the preliminary chamber, 4. An electric pressure sintering apparatus according to claim 1, further comprising a discharge cylinder for extruding from a valve onto a discharge conveyor.