Dust detection system

Abstract

Provided is a system that is capable of highly accurately detecting dust present in an internal space of a housing, and that can remove the dust. When ultrasonic vibration is applied to a housing H, dust adhering to the inner surface of the housing H and / or to the surface of a structure C is separated with high accuracy. Further, since the internal space S of the housing H is neutralized by ions, even the dust adhering to the inner surface of the housing H and / or to the surface of the structure C can be separated with high accuracy by electrification. Therefore, the dust present in the internal space S of the housing H is reliably sucked from the internal space S of the housing H by an intake device 14, and the dust can be reliably detected by a dust detection device 24.

Description

Dust Detection System

[0001] The present invention relates to a system for detecting dust.

[0002] 2 , a conventional secondary battery B includes a positive electrode plate C1 and a negative electrode plate C2 electrically insulated by a separator C4, a positive electrode current collector C12 electrically connected to the positive electrode plate C1, a negative electrode current collector C22 electrically connected to the negative electrode plate C2, and a generally hollow cylindrical housing H that accommodates and seals these components. The negative electrode terminal of the secondary battery B is formed by the bottom of the housing H, and the positive electrode terminal of the secondary battery B is formed by a lid member (not shown) that covers the top of the housing H. The open end of the housing H is joined to the lid member by crimping or the like around the entire periphery, thereby sealing the internal space S of the housing H (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-167557

[0004] If dust gets into the internal space S of the unsealed housing H during the manufacturing process of the secondary battery B, the dust may affect the performance of the finished secondary battery B. For this reason, it is necessary to inspect the internal space S of the housing H for the presence and amount of dust.

[0005] Therefore, an object of the present invention is to provide a system that can detect dust with high accuracy while removing the dust present in the internal space of a housing.

[0006] The dust detection system of the present invention comprises an air vent path having an air vent pipe inserted into the interior space of the housing through an opening of the housing, an air intake device that draws air from the interior space of the housing through the air vent path, an ultrasonic vibration device that applies ultrasonic vibrations to the housing, and a dust detection device that optically detects dust contained in the air flowing through the air vent path.

[0007] According to the dust detection system of the present invention, by applying ultrasonic vibrations to the housing, dust adhering to the inner surface of the housing is released with high accuracy. As a result, dust present in the interior space of the housing is reliably sucked out of the interior space of the housing by the intake device. Therefore, dust present in the interior space of the housing can be more reliably detected.

[0008] 1 is a diagram illustrating the configuration of a dust detection system according to an embodiment of the present invention;

[0009] (Configuration) The dust detection system 1 according to one embodiment of the present invention shown in FIG. 1 is a system for extracting and detecting dust particles present in an internal space S of a housing H having an opening H0, particularly in a space defined by a structure C having a through-hole C0, from the housing H.

[0010] The outer shape of the housing H and / or the shape of the internal space S of the housing H may be various shapes, such as a substantially cylindrical shape, a substantially prismatic shape, a substantially truncated cone shape, or a substantially truncated pyramid shape. The shape of the opening H0 of the housing H may be various shapes, such as a circular shape, an elliptical shape, or a rectangular shape. Similarly, the outer shape of the structure C may be various shapes, such as a substantially cylindrical shape, a substantially prismatic shape, a substantially truncated cone shape, or a substantially truncated pyramid shape. The shape (cross-sectional shape) of the through hole C0 of the structure C may be various shapes, such as a circular shape, an elliptical shape, or a rectangular shape. The housing H may be made of metal or synthetic resin, etc.

[0011] 2 , in one embodiment, the housing H is the housing H of the secondary battery B, and the structure C accommodated in the internal space of the housing H is composed of a positive electrode plate material C1, a negative electrode plate material C2, a separator C4 that electrically insulates the positive electrode plate material C1 and the negative electrode plate material C2, a positive electrode current collector C12 electrically connected to the positive electrode plate material C1, and a negative electrode current collector C22 electrically connected to the negative electrode plate material C2. The positive electrode plate material C1, the negative electrode plate material C2, and the separator C4 of the secondary battery B are spirally wound to form a substantially cylindrical structure C having a through-hole C0 in the approximate center.

[0012] As shown in FIG. 1, the dust detection system 1 includes a control device 10, an output interface 102, an ultrasonic vibration device 11, a static eliminator 12, an air intake device 14, an air passage 22, and a dust detection device 24.

[0013] The control device 10 is configured with a microcomputer, an arithmetic processing device (CPU, microprocessor, processor core, etc.), and a storage device (memory, such as ROM and RAM). The control device 10 is configured to control the operations of the ultrasonic vibration device 11, the static eliminator 12, the air intake device 14, and the dust detector 24.

[0014] The output interface 102 is configured as an image output device, and is configured to output the detection result from the dust detection device 24 .

[0015] The ultrasonic vibration device 11 has a piezoelectric element and a high-frequency power supply that supplies high-frequency current to the piezoelectric element, and applies ultrasonic vibrations (e.g., vibration frequencies of 20 kHz to 40 kHz) to the housing H (see the black arrow in FIG. 1). The ultrasonic vibrations are, for example, ultrasonic vibrations in a direction parallel to the central axis or longitudinal direction of the housing H and / or in a direction perpendicular to the central axis of the housing H.

[0016] The static eliminator 12 has an ion supply pipe 120, an ion supply path 121, and an ion generator 122, and is configured to supply ions generated by the ion generator 122 to the external space via the ion supply path 121 and the ion supply pipe 120. The static eliminator 12 may be omitted.

[0017] The ventilation path 22 includes an air vent pipe 220, a first ventilation path portion 221, a second ventilation path portion 222, a third ventilation path portion 223, and a dust collector 224. The dust collector 224 is connected to each of the second ventilation path portion 222 and the third ventilation path portion 223. A filter 2242 is provided in the internal space of the dust collector 224. The second ventilation path portion 222 passes through the filter 2242 and communicates with the dust collection space. The third ventilation path portion 223 communicates with a space on the opposite side of the filter 2242 from the dust collection space. The dust collector 224 may be omitted.

[0018] The ventilation pipe 220 is configured to be inserted through the opening H0 of the housing H, and the tip opening thereof is inserted into the internal space S of the housing H. The ventilation pipe 220 is configured so that, when inserted through the through-hole C0 of the structure C present in the internal space S of the housing H, the tip opening of the ventilation pipe 220 is inserted into a space of the internal space S of the housing H that is partially defined by the structure C.

[0019] The ion supply pipe 120 and the vent pipe 220 form a double pipe inserted into the internal space S through the opening H0 of the housing H, and the ion supply pipe 120 (inner pipe) is provided concentrically or eccentrically inside the vent pipe 220 (outer pipe). The double pipe or its outer pipe is formed to be slightly thinner than the opening H0 of the housing H and / or the through-hole C0 of the structure C. The ion supply pipe 120 and the vent pipe 220 may each be a pipe having various cross-sectional shapes, such as a substantially cylindrical pipe, a substantially square pipe, or a substantially regular n-sided pipe (n = 6, 8, 12, etc.). The ion supply pipe 120 and the vent pipe 220 may each be made of, for example, metal or synthetic resin and be elastically deformable.

[0020] The intake device 14 is configured by a vacuum pump or the like, and sucks air from the internal space S of the housing H through the ventilation path 22 and discharges the air to the external space through the ventilation path 22 (see the white arrow in FIG. 1 ). The intake device 14 is provided midway along the third ventilation path portion 223, but may be provided at any position along the ventilation path 22.

[0021] The dust detection device 24 optically detects dust contained in the air flowing through the ventilation path 22. The dust detection device 24 includes a laser projector 241, a scattered light sensor 242, and a chamber 244.

[0022] The laser projector 241 has a light source such as an LED and an optical system such as a lens, and is configured to irradiate the interior space of the chamber 244 with laser light. The wavelength of the laser light is, for example, 0.635 μm (red laser light) or 0.532 μm (green laser light). The scattered light sensor 242 is configured to detect the intensity of the laser light scattered by dust particles in the interior space of the chamber 244 through an optical system (for example, composed of a condenser lens, an ND filter, and a bandpass filter), thereby detecting the number or density of the dust particles. The chamber 244 is made of a material that is translucent to the laser light, at least at the location where the laser light is irradiated by the laser projector 241 and the location where the laser light is detected by the scattered light sensor 242.

[0023] The chamber 244 is located between the first air passage portion 221 and the second air passage portion 222. The cross-sectional area of ​​the chamber 244 (the area of ​​a cross section perpendicular to the central axis) is larger than the cross-sectional areas of the air passage 22 (the first air passage portion 221 and the second air passage portion 222) on the upstream and downstream sides thereof. The chamber 244 has a shape in which a substantially conical cylinder (or a substantially truncated conical cylinder) having a lower bottom surface of substantially the same diameter as the cylinder is connected to both ends of the substantially cylindrical body. That is, the cross-sectional area of ​​the chamber 244 is configured to increase continuously or intermittently from the upstream end to the downstream end, and then decrease continuously or intermittently. A guide structure may be provided inside the chamber 244 to change the airflow introduced into the chamber 244 into a spiral airflow.

[0024] The outer shape of the chamber 244 or the shape of its internal space may be various shapes, such as an approximately spherical shape, an approximately elliptical spherical shape, an approximately cylindrical shape, an approximately prism shape, an approximately truncated cone shape, an approximately truncated pyramid shape, or a combination of these (for example, a pair of truncated cones or truncated pyramid shapes that are continuous at the lower or upper base surface).

[0025] (Dust Detection Method) The procedure of the dust detection method using the dust detection system 1 configured as described above will be described. First, as shown in FIGS. 1 and 2 , a double pipe formed by the ion supply pipe 120 and the vent pipe 220 is inserted into the opening H0 of the housing H and the through-hole C0 of the structure C, and the tip of the double pipe is guided into a space within the internal space S of the housing H that is partially defined by the structure C. In this state, ultrasonic vibration is applied to the housing H by the ultrasonic vibration device 11. Furthermore, ions generated by the ion generator 122 of the static eliminator 12 are introduced from the tip of the ion supply pipe 120 into the internal space S of the housing H, thereby eliminating static electricity from the internal space S of the housing H. Then, the intake device 14 is operated, and air within the internal space S of the housing H is sucked into the air passage 22 from the tip of the vent pipe 220. Prior to the start of operation of the intake device 14, the operation of the ultrasonic vibration device 11 and / or the static eliminator 12 may be stopped.

[0026] When air flows through the internal space of chamber 244, laser projector 241 irradiates the internal space of chamber 244 with laser light, and the intensity of the laser light scattered by dust particles contained in the air is detected by scattered light sensor 242. The scattered light sensor 242 transmits the detection result (the cumulative number or density of detected dust particles, or the number or density of detected dust particles per unit time) to control device 10. Furthermore, the detection result is transmitted from control device 10 to output interface 102 and then output or displayed.

[0027] Dust is taken into a dust collection space defined by the filter 2242 in the internal space of the dust collector 224. The filter 2242 prevents the dust taken into the dust collection space from flowing into the third ventilation path portion 223.

[0028] (Effect) According to the dust detection system configured as described above, by applying ultrasonic vibrations to the housing H, dust adhering to the inner surface of the housing H and / or the surface of the structure C is released with high accuracy. Furthermore, because the internal space S of the housing H is neutralized by ions, even dust that has been charged and adhered to the inner surface of the housing H and / or the surface of the structure C can be released with even higher accuracy. Therefore, dust present in the internal space S of the housing H can be reliably sucked from the internal space S of the housing H by the intake device 14, and then reliably detected by the dust detection device 24.

[0029] (Another embodiment of the present invention) In the above embodiment, the internal space S of the housing H is neutralized by the neutralization device 12. However, in other embodiments, ions generated by the ion generator 122 of the neutralization device 12 may be supplied to the external space of the housing H, thereby neutralizing the outside of the housing H.

[0030] In the above embodiment, the ion supply pipe 120 and the vent pipe 220 form a double pipe inserted into the internal space S through the opening H0 of the housing H, and the ion supply pipe 120 (inner pipe) is provided concentrically or eccentrically inside the vent pipe 220 (outer pipe). In another embodiment, the ion supply pipe 120 and the vent pipe 220 may form a double pipe inserted into the internal space S through the opening H0 of the housing H, and the vent pipe 220 (inner pipe) may be provided concentrically or eccentrically inside the ion supply pipe 120 (outer pipe). In still another embodiment, the ion supply pipe 120 and the vent pipe 220 may each form two separate pipes inserted into the internal space S through a common or separate opening H0 of the housing H.

[0031] The chamber 244 in the above embodiment may be omitted, and the dust detecting device 24 may detect dust flowing through the ventilation path 22. In this case, the ventilation path 22 may be made of a material that is translucent to the laser light at least at the location where the laser light is irradiated by the laser projector 241 and the location where the laser light is detected by the scattered light sensor 242.

[0032] In the above embodiment, the structure C is accommodated in the internal space S of the housing H. However, in other embodiments, the structure C may not be present in the internal space S of the housing H.

[0033] 1. Dust detection system 10. Control device 11. Ultrasonic vibration device 12. Static electricity removal device 120. Ion supply pipe 121. Ion supply path 122. Ion generator 14. Intake device (pump) 22. Ventilation path 220. Ventilation pipe 221. First ventilation path section 222. Second ventilation path section 223. Third ventilation path section 224. Dust collector 2242. Filter 24. Dust detection device 241. Laser projector 242. Scattered light sensor 244. Chamber B. Secondary battery C. Structure C0. Through hole (of structure) H. Housing H0. Opening (of housing).

Claims

1. A dust detection system comprising: an air vent path having an air vent pipe inserted into the interior space of a housing through an opening in the housing; an air intake device that sucks air from the interior space of the housing through the air vent path; an ultrasonic vibration device that applies ultrasonic vibrations to the housing; and a dust detection device that optically detects dust contained in the air flowing through the air vent path.

2. A dust detection system according to claim 1, comprising an ion generator and an ion supply pipe, and a static eliminator that supplies ions generated by the ion generator to the interior space of the housing through the ion supply pipe, thereby eliminating static electricity from the interior space of the housing.

3. A dust detection system according to claim 2, wherein the ventilation pipe and the ion supply pipe form a double pipe.

4. A dust detection system according to claim 1, comprising an ion generator and a static eliminator that supplies ions generated by the ion generator to the outside of the housing to eliminate static electricity from the outside of the housing.

5. A dust detection system according to any one of claims 1 to 4, wherein the ventilation path comprises a chamber arranged between the ventilation pipe and the intake device, the chamber having a cross-sectional area larger than the cross-sectional area of ​​the ventilation path on both the upstream and downstream sides of the chamber, and the dust detection device is configured to optically detect dust contained in the air flowing through the internal space of the chamber.

6. A dust detection system according to claim 5, wherein the cross-sectional area of ​​the chamber is configured to increase continuously or intermittently from the upstream end to the downstream end, and then decrease continuously or intermittently.

7. A dust detection system as claimed in claim 1, wherein the vent pipe is inserted into a through-hole in a structure present inside the housing, and the tip of the vent pipe is located in a part of the interior space of the housing that is partially defined by the structure.

8. A dust detection system as claimed in claim 2 or 3, wherein the ion supply pipe is configured so that, when inserted into a through-hole in a structure present inside the housing, the tip of the ion supply pipe reaches a portion of the internal space of the housing that is partially defined by the structure.

9. A dust detection system according to claim 1, further comprising an output interface for outputting the detection results of said dust detection device.

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