JPH06322409A - Production and device of sheet by energizing powder rolling - Google Patents

Abstract

PURPOSE:To improve productivity. CONSTITUTION:The first rolling mill, which is provided with a pair of rolling rolls 3 to form the powder 2 feeded by a powder feeding device 1, is installed in an enclosed vessel 9. The second rolling mill 7, which is provided with a pair of rolling rolls 6 to roll the green compact 5 compacted at the first rolling mill 4, is installed on the downstream of the first rolling mill 4. An energizing circuit 15 is installed between the rolling roll 3 and rolling roll 6. By the energizing circuit 15, electric power is caused to flow through the green compact 5 in the longitudinal direction, heating the green compact 6 to high temp. by Joule heat effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a plate by electric current powder rolling in which a conductive powder such as a metal powder or a composite powder is heated and rolled to produce a plate.

[0002]

2. Description of the Related Art As a general method for manufacturing a plate by conventional powder rolling, as shown in FIG.
Then, the powder c is supplied between the pair of upper and lower rolling rolls b and rolled to form a green compact d, and the green compact d is sintered in the heating furnace e, and then between the other rolling rolls f. There is one that is rolled to produce a plate g. h indicates a winder.

In the case of the above-mentioned method for producing a plate, although the powder compact and the heating are not treated at the same time, as a method of simultaneously treating the powder compact and the heating, as shown in FIG.
An electric heating type powder rolling method has been proposed in which a voltage is applied between a pair of left and right rolling rolls i to energize a powder compact to generate heat and to sinter to produce a plate g. That is, the hopper j is provided above the pair of left and right rolling rolls i arranged in parallel.
Is installed and an energization circuit k is provided between the rolling rolls i, and the powder c charged into the hopper j is drawn into the roll gap by the rotation of the rolling roll i and sintered by Joule heat generation while being energized and heated. The plate g is continuously manufactured (Japanese Patent Laid-Open No. 2-115302). In addition, 1 shows a power supply device.

[0004]

However, the above-mentioned electric heating type powder rolling apparatus has the following problems. The powder compact formed into the plate g sandwiched between the rolling rolls i is
Since the thickness is thin and the electric resistance is small, a large current is required to generate heat at a high temperature. Since the high temperature cannot be obtained unless the powder compact is energized, that is, the time during which it is rolled by the rolling roll i, it is necessary to slow down the peripheral speed of the rolling roll i. It gets worse. If the contact time between the heat-generated compact and the rolling roll i is long, the compact is cooled on the roll surface, resulting in poor thermal efficiency.

Therefore, the present invention focuses on the fact that the electric resistance of the powder compact is larger in the length direction than in the thickness direction,
An object of the present invention is to provide a method and an apparatus for producing a plate by electric current powder rolling, which can efficiently heat a compact with a small current to enhance the productivity of the plate.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a powder having conductivity is compacted between a pair of rolling rolls arranged on the upstream side, and then the compact is compacted. When rolling between a pair of rolling rolls arranged on the downstream side, a voltage is applied between the rolling roll on the upstream side and the rolling roll on the downstream side to energize the powder compact to generate heat, and the heated pressure is applied. A method for producing a plate by electric current powder rolling, which comprises rolling a powder compact between rolling rolls on the downstream side to produce a plate.

An upstream first rolling mill provided with a pair of rolling rolls for compacting a powder having conductivity,
A second rolling mill on the downstream side, which is provided with a pair of rolling rolls for rolling the green compact compacted by the first rolling mill, is installed at a required interval, and the first rolling is performed. Between the rolling roll of the rolling mill and the rolling roll of the second rolling mill, an energizing circuit for applying a voltage to electrically heat the green compact is provided.

Further, the powder, the first rolling mill, and the second rolling mill are housed in a closed container, and the closed container is equipped with a decompressor or a non-oxidizing gas filling device, or the first rolling is performed. The rolling mill may be equipped with a rolling force adjusting device, and the second rolling mill may be equipped with a strip thickness adjusting device.

[0009]

The powder compact is formed by supplying the powder between the rolling rolls of the first rolling mill on the upstream side, and the compact is further rolled between the rolling rolls of the second rolling mill on the downstream side. It becomes a plate by doing. At this time, when the powder compact formed between the rolling roll of the first rolling mill and the rolling roll of the second rolling mill is energized by the energizing circuit, Joule heat is generated to heat it to a high temperature. Will be obtained efficiently.

When the above operation is performed in a container under a reduced pressure atmosphere or a non-oxidizing gas atmosphere, the plate is prevented from being oxidized and the product quality can be improved.

Further, when a rolling force adjusting device and a plate thickness adjusting device are used to adjust the rolling force and plate thickness to be constant in consideration of the powder characteristics and the state of the roll surface, a plate uniform in the longitudinal direction can be obtained. It will be.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a plate manufacturing apparatus by electric current powder rolling according to the present invention, in which conductive powder 2 supplied by a powder supply apparatus 1 is rolled between a pair of left and right rolling rolls 3. A first rolling machine 4 which is formed into a green compact 5 and a second rolling in which the green compact 5 formed by the first rolling machine 4 is rolled between a pair of upper and lower rolling rolls 6. The rolling mill 7 and the rolling mill 7 are installed upstream and downstream in a closed container 9 provided with a decompression device 8 with a required space therebetween, and on the shaft of one of the rolling rolls 3 of the first rolling mill 4 from the power supply device 10. Electric wire 1
1 is connected via a current collector 12, and the electric wire 1 from the power supply device 10 is connected to the shaft of one rolling roll 6 of the second rolling mill 7.
3 are connected via a current collector 14, and the rolling rolls 3, 6 are connected.
An energizing circuit 15 for energizing and heating the powder compact 5 is provided between them, and a winding machine 17 for winding the plate 16 rolled by the second rolling machine 7 is further provided in the closed container 9. Install.

The first rolling mill 4 has a hydraulic cylinder 19 which is expanded and contracted by pressure oil sent from a hydraulic power source 18.
Is equipped as a rolling force adjusting device between the rolling rolls 3,
On the other hand, the second rolling mill 7 is equipped with a hydraulic cylinder 20 that expands and contracts by the pressure oil sent from the hydraulic power source 18 as a plate thickness adjusting device between the rolling rolls 6, and further includes the first rolling mill 4 and A curved guide plate 21 made of an insulating material is arranged between the second rolling mill 7 and the second rolling mill 7.

The powder supply device 1 has a hopper 22 for receiving the charged powder 2 and a movable partition plate provided at the lower end of the hopper 22 so that the contact length of the powder 2 with the rolling roll 3 can be adjusted. 23 and a screw 25 incorporated in the hopper 22 so as to forcibly supply the powder 2 between the rolling rolls 3 by driving the motor 24.

When the plate 16 is manufactured from the powder 2, in the atmosphere in which the pressure in the closed container 9 is reduced by the pressure reducing device 8, the powder feeding device 1 is used to roll the rolling rolls 3 of the first rolling mill 4.
The powder is supplied in the meantime, and the powder compact 5 is molded by pressing between the rolling rolls 3, and the powder compact 5 is guided to the second rolling mill 7 along the guide plate 21. The rolling rolls 6 are made to bite into each other. At this time, a voltage is applied between the one rolling roll 3 of the first rolling mill 4 and one rolling roll 6 of the second rolling mill 7 by the energizing circuit 15. Apply. As a result, the powder compact 5 is energized and heated by Joule heat generation, and the heated powder compact 5 is heated.
Is effectively compressed and rolled between the rolling rolls 6 to form a high-density plate 16 and is wound up by the winder 17.

In the above, since the electric resistance of the powder compact 5 is larger in the length direction than in the thickness direction, when a current is applied between the rolling rolls 3 and 6, a small current is generated to generate a high temperature. You can Therefore, the green compact 5 is sufficiently heated in the time it takes to move between the rolling rolls 3 and 6,
The roll peripheral speed of each of the rolling mills 4 and 7 can be increased, which reduces the amount of cooling heat from the roll surface, thereby improving the productivity. Further, the powder compact 5 is
Since the pressure-reducing device 8 heat-rolls in a reduced-pressure atmosphere, the manufactured plate 16 does not oxidize and has high quality. The heating temperature of the powder compact 5 can be set by selecting various conditions such as the electrical resistance of the powder compact 5, the applied current, and the peripheral speed of the roll.

Further, in the above, since the powder 2 is forcedly pushed between the rolling rolls 3 by the powder supply device 1,
The fluidity of the powder 2 can be made constant and the rolling conditions can be stabilized. Furthermore, in the first rolling mill 4, the hydraulic cylinder 19 as a rolling force adjusting device allows the characteristics of the powder 2 and the state of the roll surface to be adjusted. Accordingly, the rolling force can be made constant and the powder can be pressed. In the second rolling mill 7, the hydraulic cylinder 20 as the plate thickness adjusting device can make the plate thickness constant. Therefore, it is possible to obtain the plate 16 that is uniform in the longitudinal direction.

In the above embodiment, the closed vessel 9 is operated under a decompressed atmosphere decompressed by the decompressor 8. However, instead of the decompressor 8,
For example, as shown by the chain double-dashed line in FIG. 1, a non-oxidizing gas filling device 26 may be installed to operate in a non-oxidizing gas atmosphere. It is needless to say that the operation can be performed below, and that various changes can be made without departing from the scope of the present invention.

[0020]

As described above, according to the present invention, the following excellent effects are exhibited. Since the powder compact is energized in the longitudinal direction to heat it, a high temperature can be obtained with a small current, and the energization circuit can be made inexpensive. Since the green compact can be sufficiently heated during the time from the first rolling mill to the second rolling mill, the roll peripheral speed can be increased and the productivity can be improved. Since the heated green compact is rolled, a high-density plate can be obtained. It is possible to prevent the oxidation of the plate and improve the product quality by operating in a closed container under a reduced pressure atmosphere by a decompression device or a non-oxidizing gas atmosphere by a non-oxidizing gas filling device. You can By providing the first rolling mill with a rolling force adjusting device and the second rolling mill with a plate thickness adjusting device, it is possible to manufacture a plate that is uniform and stable in the longitudinal direction.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an apparatus for manufacturing a plate by electric current powder rolling according to the present invention.

FIG. 2 is a schematic view showing an example of a conventional method for producing a plate by powder rolling.

FIG. 3 is a schematic view showing an example of a conventional electric heating type powder rolling apparatus.

[Explanation of Codes] 2 Powder 3 Rolling Roll 4 First Rolling Mill 5 Powder Compacting Body 6 Rolling Roll 7 Second Rolling Machine 8 Pressure Reduction Device 9 Closed Container 15 Energizing Circuit 16 Plate 19 Hydraulic Cylinder (Rolling Force Adjusting Device) 20 Hydraulic Pressure Cylinder (plate thickness adjusting device) 26 Non-oxidizing gas filling device

Claims (4)

[Claims] 1. When the conductive powder is compacted between a pair of rolling rolls arranged on the upstream side and then the compacted body is rolled between a pair of rolling rolls arranged on the downstream side, A voltage is applied between the rolling roll on the upstream side and the rolling roll on the downstream side to energize the powder compact to generate heat, and the heated powder compact is rolled between the downstream rolls to produce a plate. A method for producing a plate by electric current powder rolling, comprising: 2. A first rolling mill on the upstream side provided with a pair of rolling rolls for compacting conductive powder, and a compacted body compacted by the first rolling mill. The second rolling mill on the downstream side, which is provided with a pair of rolling rolls for, is installed at a required interval, and between the rolling roll of the first rolling mill and the rolling roll of the second rolling mill, An apparatus for producing a plate by electric current powder rolling, comprising a current supply circuit for applying a voltage to electrically heat the green compact. 3. The electrically conductive powder according to claim 2, wherein the powder, the first rolling mill and the second rolling mill are housed in a closed container, and the closed container is equipped with a decompression device or a non-oxidizing gas filling device. Plate manufacturing equipment by rolling. 4. The apparatus for producing a plate by electric current powder rolling according to claim 2, wherein the first rolling mill is equipped with a rolling force adjusting device, and the second rolling mill is equipped with a plate thickness adjusting device.