JP2009235442A - Powder rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder rolling device which can stably produce a sheet material whose density and thickness are uniform by preventing the sticking of powder to preliminary rolling reduction rolls. <P>SOLUTION: The powder rolling device 1 includes: rolling rolls 4A, 4B rolling metal powder 2; and a preliminary rolling reduction roll 7A subjecting the metal powder 2 to preliminary rolling reduction in a space with the rolling roll 4A, and has a constitution including a heating apparatus 20 heating the preliminary rolling reduction roll 7A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a powder rolling apparatus for producing a sheet material by rolling a powder between rolling rolls.

Conventionally, for example, the powder rolling apparatuses described in Patent Document 1 and Patent Document 2 are known as powder rolling apparatuses that can obtain a thin sheet material without fluctuation in thickness.
The powder rolling apparatus has a preliminary reduction roll that preliminarily reduces the powder between one of a pair of rolling rolls, thereby rolling the powder to a thickness thinner than the thickness corresponding to the biting angle of the rolling roll. Therefore, a sheet material thinner than the conventional one can be manufactured stably.
JP 2002-212608 A JP 2005-139536 A

  However, depending on the environment of the installation location where the powder rolling device is provided, moisture in the air adheres to the peripheral surface of the pre-rolling roll due to condensation or the like, and part of the powder pre-rolled during the pre-rolling May adhere (stick) to the pre-rolled roll. When the pre-rolled powder is pre-rolled again with the rolling roll while adhering to the pre-rolling roll, the density and thickness are partially increased at the adhering portion, and the sheet material with non-uniform density and thickness is formed. There is a problem that it is manufactured and affects the quality and yield of the product.

  The present invention has been made in view of the above-described problems, and provides a powder rolling device that can stably produce a sheet material having a uniform density and thickness by preventing powder from adhering to a pre-rolling roll. For the purpose.

In order to solve the above-mentioned problems, the present invention is a powder rolling device comprising a rolling roll for rolling powder and a pre-rolling roll for pre-rolling the powder between the rolling rolls, wherein the pre-rolling A configuration having a heating device for heating the roll is employed.
By adopting such a configuration, in the present invention, it is possible to prevent moisture from adhering to the peripheral surface of the preliminary reduction roll by heating the preliminary reduction roll.

Moreover, in this invention, the structure which provides the heat_generation | fever means of the said heating apparatus inside the said pre-rolling roll is employ | adopted.
By adopting such a configuration, in the present invention, the entire pre-rolling roll can be uniformly and efficiently heated from the inside of the pre-rolling roll using thermal conductivity.

Moreover, in this invention, the said heating apparatus employ | adopts the structure of heating the said pre-reduction roll so that the temperature in the surrounding surface of the said pre-reduction roll may be 40 to 100 degreeC.
By adopting such a configuration, in the present invention, it is possible to prevent moisture from adhering to the pre-rolling roll by heating at 40 ° C. or higher, which is higher than the temperature throughout the seasons, and to prevent powder (for example, copper powder) By heating at a temperature lower than 100 ° C., which is a temperature at which the metal powder) is easily oxidized, it is possible to prevent deterioration due to oxidation of the powder that is pressed down by the heated preliminary reduction roll.

Moreover, in this invention, the said heating apparatus employ | adopts the structure of heating the said pre-reduction roll so that the temperature in the surrounding surface of the said pre-reduction roll may be kept constant.
By adopting such a configuration, in the present invention, it is possible to suppress deformation of the pre-rolling roll due to thermal expansion accompanying temperature change, and to keep the shape of the pre-rolling roll constant.

Moreover, in this invention, the said heating apparatus employ | adopts the structure of heating the said pre-reduction roll at the time of the start of the said pre-reduction.
By adopting such a configuration, in the present invention, it is possible to prevent the powder that is particularly likely to be generated at the start of the pre-rolling from adhering to the peripheral surface of the pre-rolling roll.

According to the present invention, there is provided a powder rolling apparatus comprising a rolling roll for rolling powder and a preliminary reduction roll for preliminarily reducing the powder between the rolling roll, and a heating apparatus for heating the preliminary reduction roll. By adopting the configuration, it is possible to prevent moisture from adhering to the peripheral surface of the pre-rolling roll due to condensation or the like. That is, it is possible to prevent the powder from adhering to the pre-rolling roll due to the adhesion of moisture.
Therefore, according to the present invention, the powder adhering to the pre-rolling roll can be prevented from being pre-rolled again with the rolling roll, so that a sheet material having a uniform density and thickness can be stably produced. There is an effect that can be done.

Hereinafter, an embodiment of a powder rolling apparatus of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic configuration diagram of a powder rolling apparatus 1 in the present embodiment.
FIG. 2 is an arrow view (the hopper 3A and the belt feeder 5A are not shown) as viewed from the arrow X of the powder rolling apparatus 1 in FIG.
As shown in FIG. 1, the powder rolling device 1 is disposed above a pair of rolling rolls 4A and 4B that are horizontally and in parallel and one rolling roll 4A, and a metal powder (powder) via a belt feeder 5A. 2, a pre-rolling roll 7A that pre-rolls the metal powder 2 between the rolling roll 4A, and a heating device 20 that heats the pre-rolling roll 7A, between the rolling rolls 4A and 4B. A sheet guide (not shown) for guiding the roll-formed sheet material to the next process is disposed below the sheet.

  The rolling rolls 4A and 4B are controlled to rotate independently of each other and to rotate synchronously at the same speed. In some cases, the sheet material is controlled to rotate at different constant speeds in order to apply a shearing force to the sheet material. Specifically, as shown in FIG. 2, the rolling roll 4A (4B) is supported at both ends by a housing 10 and a bearing 11, and can be rotated around an axis by a drive mechanism (not shown). It has become. Further, the gap between the rolling rolls 4A and 4B is adjustable by the linear motion guide mechanism 12, and the thickness of the rolled sheet material can be arbitrarily changed.

  Returning to FIG. 1, the hopper 3 </ b> A has a hollow structure whose diameter gradually decreases as the cross-sectional shape goes downward, stores the metal powder 2, and surrounds the circumferential surface of the rolling roll 4 </ b> A via a belt feeder 5 </ b> A connected to the bottom. It is the structure which supplies the metal powder 2 toward this.

  The belt feeder 5A is provided at the bottom of the hopper 3A, and is configured to convey the metal powder 2 from the hopper 3A by being connected to a rotational drive mechanism (not shown) and rotationally driven. Further, the belt feeder 5A is configured such that the conveyance destination is located above the rolling roll 4A and the metal powder 2 is supplied onto the peripheral surface of the rolling roll 4A. Furthermore, the belt feeder 5A has substantially the same width as the width of the rolling roll 4A, and can supply the metal powder 2 uniformly over the width direction of the rolling roll 4A.

The pre-rolling roll 7A has a cylindrical shape having a diameter smaller than that of the rolling rolls 4A (and 4B), specifically, 20% or less of the diameter of the rolling rolls 4A and 4B. The heating wire (heat generating means) 21 of the device 20 is configured to be inserted in the axial direction (see FIG. 2). As shown in FIG. 1, the rotation center of the pre-rolling roll 7A is installed at a position of an angle θ1 from the upper side in the vertical direction to the rolling roll 4B side with respect to the rotation center of the rolling roll 4A. The angle can be selected between 0 ° and 85 °. Here, θ1 = 30 ° is set.
Moreover, the unevenness | corrugation is formed in the outer peripheral surface of the pre-rolling roll 7A, and it is easy to bite the supplied metal powder 2. The unevenness may be uniform or non-uniform. Further, depending on the properties of the metal powder 2, a flat roll having a smooth outer peripheral surface may be used. Further, instead of a flat roll, a roll having a concave crown or a convex crown may be used.

  The pre-rolling roll 7A is provided with a rotation mechanism (not shown), and can be adjusted independently to an arbitrary rotation speed (circumferential speed) with respect to the rolling rolls 4A and 4B. The axial distance between the pre-rolling roll 7A and the rolling roll 4A can be arbitrarily adjusted, and therefore the gap between these rolls can be finely adjusted.

  As shown in FIG. 2, the heating device 20 includes a heating wire 21 that heats the pre-rolling roll 7 </ b> A from the inside, and electrode pairs 22 </ b> A and 22 </ b> B that apply a voltage to the heating wire 21 to energize the heating wire 21. .

The heating wire 21 is, for example, a filament wire composed of a nickel chrome heating wire or an iron chrome heating wire that conducts heat, and the hollow portion of the preliminary reduction roll 7A is concentric with the rotating shaft of the preliminary reduction roll 7A. It arrange | positions so that it may penetrate in an axial direction. A plurality of heating wires 21 may be arranged linearly in the axial direction, or may be arranged by providing a shaft that passes through the pre-rolling roll 7A and winding it around the shaft in a coil shape. There may be.
Such a heating wire 21 is exposed from both axial ends of the pre-rolling roll 7A, and has one end electrically connected to the electrode pair 22A and the other end electrically connected to the electrode pair 22B.

The electrode pairs 22A and 22B are configured to apply a voltage to the heating wire 21 to conduct electricity under the control of the heating device 20, and to heat the preliminary reduction roll 7A so that the peripheral surface of the preliminary reduction roll 7A is 40 ° C to 100 ° C. It has become. The reason why the lower limit temperature is set to 40 ° C. is that the temperature hardly exceeds 40 ° C. throughout the four seasons. Therefore, if the peripheral surface of the pre-rolling roll 7A is 40 ° C. or more, preliminary reduction due to condensation or the like. This is because moisture in the air can be prevented from adhering to the peripheral surface of the roll 7A. Moreover, the reason why the upper limit temperature is set to 100 ° C. is that the metal powder 2 is likely to be oxidized by a chemical reaction with oxygen in the air at a high temperature, which may affect the quality of the product. For example, since the copper powder which is an example of the powder used for the metal powder 2 tends to be oxidized particularly when the temperature is raised to 100 ° C., the upper limit is set to 100 ° C.
Further, the electrode pairs 22A and 22B are controlled so as to make the voltage applied to the heating wire 21 constant so as to keep the pre-rolling roll 7A at a constant temperature. By controlling in this way, deformation due to thermal expansion of the pre-rolling roll 7A can be suppressed, and the gap between the pre-rolling roll 7A and the rolling roll 4A can be accurately maintained at a predetermined distance.

Next, the operation of the powder rolling apparatus 1 having the above-described configuration will be described with reference to FIGS. 1 and 2 along the procedure for manufacturing the sheet material.
First, the powder rolling device 1 operates the heating device 20 to heat the pre-rolling roll 7A. Specifically, the heating device 20 applies a voltage to the heating wire 21 to the electrode pairs 22A and 22B, and causes the heating wire 21 to generate heat by electrical conduction. The heat generated by the heating wire 21 is thermally conducted from the inside of the preliminary reduction roll 7A to the outside of the preliminary reduction roll 7A, and increases the temperature of the peripheral surface of the preliminary reduction roll 7A. At this time, since the heating wire 21 is disposed concentrically with the rotating shaft of the preliminary reduction roll 7A, the preliminary reduction roll 7A can be heated uniformly.
As described above, by preheating the pre-rolling roll 7A using the heating device 20 before the start of operation, it is possible to remove a large amount of water adhering to the peripheral surface of the pre-rolling roll 7A when the operation is stopped. In addition, it is possible to prevent the metal powder 2 that is particularly likely to be generated from adhering to the peripheral surface of the pre-rolling roll 7A at the start of the pre-rolling between the pre-rolling roll 7A and the rolling roll 4A.

When the pre-rolling roll 7A reaches a predetermined temperature (for example, 40 ° C.), the powder rolling device 1 then rolls the metal powder 2 stored in the hopper 3A through a belt feeder 5A connected to the bottom of the hopper 3A. It supplies continuously over the width direction of the rolling roll 4A toward the peripheral surface of the roll 4A.
The metal powder 2 supplied on the rolling roll 4A is preliminarily rolled between the pre-rolling roll 7A and the rolling roll 4A. Here, since the pre-rolling roll 7A has a smaller diameter than the rolling roll 4A and the contact arc length is small, the metal powder 2 to be drawn is reduced, and as a result, compared with the case of rolling between the rolling rolls 4A and 4B. Can be rolled thinly.
The metal powder 2 is deaerated by being preliminarily rolled between the pre-rolling roll 7A and the rolling roll 4A, and the metal powder 2 having a constant density and a constant thickness is quantitatively determined, and the rolling rolls 4A and 4B. Will be supplied in between.

  Here, since the preliminary reduction roll 7A is heated by the heating device 20, adhesion of moisture in the air to the peripheral surface of the preliminary reduction roll 7A due to condensation or the like is prevented. Furthermore, even if the metal powder 2 contains moisture in the air, the pre-rolling roll 7A also has an action of volatilizing / evaporating the moisture of the metal powder 2 that has come into contact because the peripheral surface is heated. Therefore, it is possible to prevent a part of the metal powder 2 that has undergone preliminary reduction from adhering (attaching) to the peripheral surface of the preliminary reduction roll 7A in a state where the relative speed is substantially zero.

And the rolling rolls 4A and 4B are inserted between the metal powder 2 supplied between the rolling rolls 4A and 4B and the rolling rolls 4A and 4B from the upper side to the lower side by being rotationally driven at a predetermined distance. The sheet-like metal plate 21 is rolled. By the rolling, the metal powder 2 is fixed to the metal plate 21 to form a sheet material.
The sheet material rolled to a desired thickness between the rolling rolls 4A and 4B is sent to the next process (for example, a sintering process) along the sheet guide. Even if the irregularities formed on the outer peripheral surface of the pre-rolling roll 7A are transferred to the sheet material, the surface shape of the pre-rolling roll 7A is the same as that of the sheet material because it is formed smoothly by rolling with the rolling rolls 4A and 4B. Does not affect surface gloss.

Therefore, according to this embodiment mentioned above, with the powder rolling apparatus 1 provided with rolling roll 4A, 4B which rolls the metal powder 2, and the pre-rolling roll 7A which pre-rolls the metal powder 2 between the rolling rolls 4A. By adopting the configuration in which the heating device 20 that heats the preliminary reduction roll 7A is employed, it is possible to prevent moisture from adhering to the peripheral surface of the preliminary reduction roll 7A. That is, it is possible to prevent the metal powder 2 from adhering to the pre-rolling roll 7A due to moisture in the air adhering to the peripheral surface of the pre-rolling roll 7A due to condensation or the like.
Therefore, according to the present embodiment, the metal powder 2 attached to the pre-rolling roll 7A is not pre-rolled again with the rolling roll 4A, and a sheet material having a uniform density and thickness is stably produced. There is an effect that can be done.

  Further, in the present embodiment, by adopting a configuration in which the heating wire 21 which is a heating means of the heating device 20 is provided inside the pre-rolling roll 7A, the entire pre-rolling roll 7A from the inside is utilized using thermal conductivity. It can heat uniformly and efficiently.

  Moreover, in this embodiment, the heating apparatus 20 employs a configuration in which the pre-rolling roll 7A is heated so that the temperature on the peripheral surface of the pre-rolling roll 7A is 40 ° C. to 100 ° C. Is heated at a high temperature of 40 ° C. or higher to prevent moisture from adhering to the pre-rolling roll 7A, and is heated at a temperature lower than 100 ° C. at which the metal powder 2 is easily oxidized. Deterioration due to oxidation of the metal powder 2 preliminarily reduced by the reduction roll 7A can be prevented.

  In the present embodiment, the heating device 20 employs a configuration in which the pre-rolling roll 7A is heated so as to keep the temperature on the peripheral surface of the pre-rolling roll 7A at a constant temperature. By suppressing the deformation of the preliminary reduction roll 7A and keeping the shape of the preliminary reduction roll 7A constant, the gap between the preliminary reduction roll 7A and the rolling roll 4A can be accurately maintained at a predetermined distance.

  Further, in the present embodiment, the heating device 20 employs a configuration in which the preliminary reduction roll 7A is heated at least at the start of the preliminary reduction, so that the preliminary preparation of the metal powder 2 that is particularly likely to occur at the start of the preliminary reduction. Adhesion to the peripheral surface of the rolling roll 7A can be prevented.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, it has been described that the heating means of the heating device 20 is the heating wire 21, but the present invention is not limited to the above configuration, and for example, a heating medium heated in the pre-rolling roll 7 </ b> A. (For example, gas, water, oil, etc.) may be circulated to heat the pre-rolling roll 7A. Further, the heating device 20 may be configured such that a heating means is provided outside the preliminary reduction roll 7A and the peripheral surface of the preliminary reduction roll 7A is heated from the outside.
Furthermore, if it is the structure which controls a drive of the heating apparatus 20 based on the humidity detection result using a hygrometer, the pre-rolling roll 7A can be heated so that condensation may be prevented suitably.

  In the above embodiment, the heating device 20 does not always have to be heated in order to prevent moisture from adhering to the pre-rolling roll 7A. It has been confirmed by experiments that if the preliminary reduction roll 7A is repeatedly subjected to preliminary reduction for a certain period of time, the metal powder 2 will not adhere even if it is not heated. The driving of the device 20 may be stopped. By controlling in this way, the operating cost of the powder rolling apparatus 1 can be reduced.

  Moreover, in the said embodiment, although the powder rolling apparatus 1 demonstrated rolling the metal powder 2 to the single side | surface of the metal plate 21, and forming a sheet | seat material, the hopper 3A, the belt feeder 5A, and preliminary reduction also on the rolling roll 4B side. If the roll 7A and the heating device 20 are provided symmetrically with the rolling roll 4A side, the metal powder 2 can be rolled over the entire surface of both surfaces of the metal plate 21, and a three-layer sheet material can be formed. is there.

  In the above embodiment, the powder rolling device 1 has been described as rolling the metal powder 2 and the metal plate 21 with the rolling rolls 4A and 4B. However, the metal plate 21 is not essential for forming the sheet material, and the metal plate 21 is used. The structure which does not use may be sufficient.

It is a schematic block diagram of the powder rolling apparatus in embodiment of this invention. It is an arrow X figure in FIG. 1 of the powder rolling apparatus in embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Powder rolling apparatus, 2 ... Metal powder (powder), 4A, 4B ... Roll, 7A ... Pre-rolling roll, 20 ... Heating device, 21 ... Heating wire (heating means)

Claims (5)

A powder rolling device comprising a rolling roll for rolling powder, and a pre-rolling roll for pre-rolling the powder between the rolling rolls,
A powder rolling apparatus comprising a heating device for heating the preliminary reduction roll.   The powder rolling device according to claim 1, wherein a heating means of the heating device is provided inside the pre-rolling roll.   3. The powder rolling device according to claim 1, wherein the heating device heats the preliminary reduction roll so that a temperature on a peripheral surface of the preliminary reduction roll is 40 ° C. to 100 ° C. 4.   The said rolling device heats the said preliminary rolling roll so that the temperature in the surrounding surface of the said preliminary rolling roll may be kept constant, The powder rolling apparatus as described in any one of Claims 1-3 characterized by the above-mentioned.   The powder rolling device according to any one of claims 1 to 4, wherein the heating device heats the preliminary reduction roll at least at the start of the preliminary reduction.

Images