US-12623232-B2 - Electric dust collector and dust collection method using same

US12623232B2US 12623232 B2US12623232 B2US 12623232B2US-12623232-B2

Abstract

Provided is an electric precipitator that collects dusty foreign matter by an electrostatic force, including: a laminated sheet at least including a dust collection layer that holds the dusty foreign matter in contact, a first electrode layer, a second electrode layer, and an insulation layer, the dust collection layer, the first electrode layer, the second electrode layer, and the insulation layer being laminated; and a power supply device that applies voltages across the first and second electrode layers. The insulation layer at least has a first insulation layer that insulates the dust collection layer and the first electrode layer, a second insulation layer that insulates the first electrode layer and the second electrode layer, and a third insulation layer that insulates the second electrode layer and a portion under the second electrode layer. Films having a surface resistivity of 10 4 to 10 8 Ω are used for the first and second electrode layers.

Inventors

Takaaki Hasegawa
Hiroyuki Moriyama

Assignees

CREATIVE TECHNOLOGY CORPORATION

Dates

Publication Date: 20260512
Application Date: 20221004
Priority Date: 20211006

Claims (8)

1 . An electric precipitator that collects dusty foreign matter by an electrostatic force, comprising: a laminated sheet at least including a dust collection layer that holds the dusty foreign matter in contact, a first electrode layer, a second electrode layer, and an insulation layer, the dust collection layer, the first electrode layer, the second electrode layer, and the insulation layer being laminated; and a power supply device that applies voltages across the first and second electrode layers, wherein the insulation layer at least has a first insulation layer that insulates the dust collection layer and the first electrode layer, a second insulation layer that insulates the first electrode layer and the second electrode layer, and a third insulation layer that insulates the second electrode layer and a portion under the second electrode layer, and films having a surface resistivity of 10 4 to 10 8 Ω are used for the first and second electrode layers.
2 . The electric precipitator according to claim 1 , wherein the first electrode layer has a plurality of lost portions extending through in a thickness direction of the first electrode layer, the lost portions have an area ratio of 3% to 50% of a total area of the first electrode layer, and the first electrode layer including the lost portions is larger in top view than the second electrode layer by 2 to 10 mm at an end, and the first and second electrode layers are laminated with an interposition of the second insulation layer in a thickness direction of the laminated sheet.
3 . The electric precipitator according to claim 1 , wherein during use, the electric precipitator is used with a negative voltage applied to the first electrode layer and a positive voltage applied to the second electrode layer, and in a case in which a dust collection target contains a conductor, voltages depending on distances from a dust-emitting part are applied such that y≤1.7x+2.2 is satisfied where the voltage to be applied to the first electrode layer is −y kilovolt (kV) and the voltage to be applied to the second electrode layer is x kilovolt (kV).
4 . The electric precipitator according to claim 1 , wherein during use, the electric precipitator is used with a negative voltage applied to the first electrode layer and 0 V to a positive voltage applied to the second electrode layer, and in a case in which a dust collection target does not contain a conductor, a voltage of more than or equal to 0 V is applied to the second electrode layer and a voltage depending on a distance from a dust-emitting part is applied to the first electrode layer.
5 . The electric precipitator according to claim 1 , further comprising close-contact fixation means for installation and fixation in close contact with a target object.
6 . The electric precipitator according to claim 1 , wherein a resin material or a sticking material having an elastic modulus of more than or equal to 0.5 MPa and less than or equal to 10 MPa and a three-dimensional average surface roughness (SRa) of more than or equal to 0.01 μm and less than or equal to 0.55 μm is used for the dust collection layer.
7 . A method for collecting dusty foreign matter containing a conductor using the electric precipitator according to claim 1 , wherein during use, the electric precipitator is used with a negative voltage applied to the first electrode layer and a positive voltage applied to the second electrode layer, and voltages depending on distances from a dust-emitting part are applied such that y≤1.7x+2.2 is satisfied where the voltage to be applied to the first electrode layer is −y kilovolt (kV) and the voltage to be applied to the second electrode layer is x kilovolt (kV).
8 . A method for collecting dusty foreign matter not containing a conductor using the electric precipitator according to claim 1 , wherein during use, the electric precipitator is used with a minus voltage applied to the first electrode layer and 0 V to a plus voltage applied to the second electrode layer, and a voltage of more than or equal to 0 V is applied to the second electrode layer and a voltage depending on a distance from a dust-emitting part is applied to the first electrode layer.

Description

TECHNICAL FIELD This invention relates to a field in which dusty foreign matter is emitted directly by material processing such as cutting machining, punching, or cutting, a field in which a material is scraped by a packaging machine, a baling machine, or the like, or a field in which dusty foreign matter is emitted indirectly by abrasion caused by operation of a movable part of a device, an opening/closing part of a door, or the like, and more particularly relates to an electric precipitator that can collect dust such as fine particles and small swarf/chips utilizing an electrostatic force, the dust being emitted during the stamping process using a press mold. BACKGROUND ART When an article to be processed (workpiece) is punched with a mold during material processing such as stamping process, dusty foreign matter such as fine particles and small swarf/chips is emitted due to, for example, friction between the punched workpiece and the mold. There is a concern that the dusty foreign matter emitted in such a situation of material processing will flow onto a workpiece surface because of an influence of airflow generated by driving, atmosphere, or heat (in the case of a mold, for example, negative pressure when the mold is opened/closed), and furthermore, that fine particles will remain floating in the air for a long time to contaminate a surrounding environment and naturally drops to adhere onto the workpiece, thus causing product failures such as dents, hollows, scratches, and interfusion during subsequent processing. Therefore, in order to deal with the above-described failures resulting from such dusty foreign matter, a method such as attraction with magnets in a case where the dusty foreign matter is magnetic metal or removal by air suctioning, for example, have been conventionally employed. However, the effect of application of a magnet is limitedly applicable to magnetic materials and is therefore ineffective for dusty foreign matter composed of non-magnetic metals or other materials. On the other hand, taking a forming press as an example, because of the characteristics of the forming press, a mold is in a sealed state in the instant of punching when most of the fine particles are emitted, and the pressure is negative when the mold is opened. Thus, in such a case, suctioning by air cannot be expected to exert a sufficient effect, and indeed is less effective for dust collection. On the other hand, a method for blowing air onto dusty foreign matter to remove the dusty foreign matter by a blowing effect has also been conventionally used. Patent Literature 1, for example, proposes, in a pressing apparatus according to a technology antecedent thereto, a method such as effectively supplying compressed gas directed toward a predetermined site in order to more effectively remove dusty foreign matter accumulated between a lower mold and a knockout. Although this is relatively effective at blowing away large foreign matter, such a method by blowing air might adversely blow up and disperse fine dusty foreign matter such as fine particles in the air and therefore has a limited effect in terms of preventing adhesion to a workpiece considering fine dusty foreign matter such as fine particles as well. Besides, a method through use of an air purifier of a filter type, an electric precipitation type, or the like, which is generally used to deal with foreign matter, requires a certain degree of size to be ensured because of the configuration of the air purifier. It is therefore difficult to install the air purifier in the inside of or in the vicinity of a material processing device such as a mold which has a limited space and particularly in the vicinity of a punching blade where a large amount of dusty foreign matter is emitted, and when installed outside the device, a sufficient effect of collecting particles (dusty foreign matter) emitted inside the device cannot be expected. In addition, even if an airflow path from the outside of the device to a place inside the device where dust is emitted is provided to collect dust, the method through use of an air purifier turns out to be similar to the above-described air suctioning and is less effective in dust collection. In the meanwhile, as a method for attracting particles (dusty foreign matter) and collecting dust in question in a procedure of manufacturing semiconductor and liquid crystal displays, a method for collecting dust using a coulomb-type electrostatic chuck as described in Patent Literature 2, for example, has been conventionally proposed. Such a method does not have the disadvantages of the method through use of magnets and the method through use of air as described above, and enables collection of foreign matter utilizing static electricity. In such a coulomb-type electrostatic chuck in which electrodes are aligned in the horizontal direction and an electric field is thus produced in a gap between the electrodes, however, lines of electric force concentrate