JP2007128915A - Grounding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reaalize a grounding method less likely to be a generation source of electromagnetic wave noise. <P>SOLUTION: Two objects 1 capable of charging are connected to each other by using a conductor 2 with a surface resistance set from 10<SP>5</SP>to 10<SP>13</SP>Ω, and furthermore, one of the objects 1 is grounded by using a similar conductor 2. Since the conductor 2 has a surface resistance limited in the above range, it is difficult to function as a reception or a transmission of an electromagnetic wave, so that it is less likely to be a generation source of the electromagnetic wave noise. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a grounding method, a grounding conductor, and an electronic device, and more particularly to a grounding method for grounding an object that can be charged, a grounding conductor that can be used in the grounding method, and an electronic device including an electronic component. .

  Amusement machines such as pachinko machines and throttle machines are becoming mainstream with built-in electronic circuits including electronic parts such as IC and LSI. Such an electronic circuit built in the gaming machine is mainly for adjusting a prize winning or so-called a prize, and is usually arranged at the center of the gaming machine. Further, such a gaming machine is provided with a shield measure using a metal plate or the like in order to prevent an electronic circuit from malfunctioning due to the influence of an external electromagnetic wave.

  By the way, the above-mentioned gaming machine has a mechanism for moving an independent metal member such as a pachinko ball or a coin in the space due to its characteristics. Such metal members may generate electromagnetic noise when they collide with each other or various metal parts in the gaming machine. This electromagnetic wave noise, like electromagnetic waves from outside the gaming machine, may act on electronic components inside the gaming machine and cause the electronic circuit to malfunction. For this reason, in the gaming machine described above, in order to remove electromagnetic noise generated inside the gaming machine, various components inside the machine are grounded using metal wires.

  In the grounding method in the gaming machine as described above, electric charges charged in various parts in the gaming machine can be removed through the metal wire, so that generation of electromagnetic noise in the gaming machine can be suppressed. However, the metal wire used in this grounding method may simultaneously act as an antenna for receiving or transmitting electromagnetic waves. For example, when the above-mentioned metal member moves on an insulating member arranged in the gaming machine, the surface of the metal member is charged. When the charged metal member and the metal wire are close to each other or become conductive, the metal wire may act as an antenna to generate a pulsed electromagnetic wave. That is, in the grounding method using the metal wire as described above, the metal wire itself may cause electromagnetic noise.

  An object of the present invention is to realize a grounding method that is unlikely to be a source of electromagnetic noise.

  Another object of the present invention is to realize an electronic device in which electromagnetic noise is less likely to occur inside.

The grounding method according to the present invention is a method for grounding an object that can be charged. In this method, an object is grounded using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω.
Since such a grounding method of the present invention uses a conductor, it is possible to smoothly remove charges charged on the object. At the same time, the conductor used here has a surface resistance limited to a range of 10 ⁵ to 10 ¹³ Ω, and therefore does not easily function as an antenna for receiving or transmitting electromagnetic waves. For this reason, this grounding method itself is unlikely to be a source of electromagnetic noise.

Another grounding method according to the present invention is a method for grounding a plurality of objects that can be charged. In this method, grounding is performed while connecting a plurality of objects using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω.
As in the case of the above-described grounding method, this grounding method itself is unlikely to be a source of electromagnetic noise. Further, in this method, since a plurality of objects that can be charged are connected to each other while being grounded, the removal of charges from the objects can be facilitated, and at the same time, the generation of electromagnetic noise can be more effectively suppressed. be able to.

The grounding conductor according to the present invention has a surface resistance of 10 ⁵ to 10 ¹³ Ω.
Such a grounding conductor according to the present invention has a surface resistance set in a certain range, and therefore can remove charges smoothly and is unlikely to be a source of electromagnetic noise.

The electronic device according to the present invention includes an electronic component and other components other than the electronic component. The electronic component and other components are grounded independently from each other using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω.
In such an electronic apparatus of the present invention, since the electronic component and other components are grounded, the electric charges charged in these can be removed smoothly. At the same time, the conductor used here has a surface resistance limited to the range of 10 ⁵ to 10 ¹³ Ω, so it is difficult to function as an antenna for receiving or transmitting electromagnetic waves and generates electromagnetic noise. Hateful. For this reason, in this electronic device, malfunctions of electronic components are unlikely to occur.

The electronic apparatus includes, for example, a plurality of other parts described above, and at least a part between the other parts is connected using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω. In this case, electric charges charged in other components can be more effectively removed, and at the same time, generation of electromagnetic noise can be more effectively suppressed.

  In addition, the other components described above included in the electronic device include, for example, a member for moving a metal member in the space. In this case, the metal member is charged by moving in the space and easily gives electromagnetic wave noise to the conductor. However, since the surface resistance of the conductor is in the above range, the conductor itself is a source of electromagnetic noise. Hard to become.

Furthermore, another electronic device according to the present invention includes an electronic component and other components excluding the electronic component. At least one of the electronic component and the other component is grounded using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω.
In such an electronic apparatus of the present invention, since at least one of the electronic component and the other component is grounded, the electric charges charged in these can be removed smoothly. At the same time, the conductor used here has a surface resistance limited to the range of 10 ⁵ to 10 ¹³ Ω, so it is difficult to function as an antenna for receiving or transmitting electromagnetic waves and generates electromagnetic noise. Hateful. For this reason, in this electronic device, malfunctions of electronic components are unlikely to occur.

  In the grounding method of the present invention, since the surface resistance is grounded using a conductor having the above-mentioned range, it is difficult to be a source of electromagnetic noise.

  Moreover, since the grounding conductor of the present invention has a surface resistance set in the above-described range, it is difficult to be a source of electromagnetic noise.

  In addition, since the electronic device of the present invention grounds an electronic component or other components using a conductor having a surface resistance in the above-described range, it is difficult for electromagnetic noise to be generated inside.

Embodiment 1
An embodiment of a grounding method according to the present invention will be described with reference to FIG. In the figure, an object 1 is an object that can be charged, and is made of a conductive member such as metal or an insulating member such as resin. In the grounding method of the present invention, the object 1 is grounded using the conductor 2 configured in a linear shape. Here, one end of the conductor 2 is connected to the object 1, and the other end is connected to the ground using a ground bar, a ground plate, or the like.

The conductor 2 has a surface resistance set to 10 ⁵ to 10 ¹³ Ω. If the surface resistance is less than 10 ⁵ Ω, the charge charged on the object 1 can be efficiently removed, but the conductor 2 itself can easily function as an antenna for receiving or transmitting electromagnetic noise, and as a result. The conductor 2 itself tends to generate pulsed electromagnetic waves. On the other hand, when the surface resistance exceeds 10 ¹³ Ω, it becomes difficult to remove the electric charge charged on the object 1, and it becomes difficult for the conductor 2 to sufficiently exhibit the function for grounding.

  Here, the surface resistance is a value obtained by forming a silver electrode with a certain interval (for example, 1 cm) on the surface of the conductor 2 and measuring a resistance value therebetween using an insulation resistance meter.

  The conductor 2 exhibiting such surface resistance is, for example, butadiene-acrylonitrile copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), acrylic rubber, silicone rubber, or fluororubber. And rubbers such as urethane rubber, thermoplastic elastomers such as ethylene-propylene-diene copolymer rubber (EPDM), or polyethylene resin, polypropylene resin, urethane resin, vinyl chloride resin, ethylene-vinyl acetate copolymer resin, etc. It can be prepared by adding a conductive substance to a thermoplastic resin, mixing it using an extrusion kneader, a kneader, a heating roll, or the like and forming it into a linear shape.

  Two or more kinds of the above rubbers, thermoplastic elastomers and thermoplastic resins may be used in combination. Examples of the conductive material include various carbon blacks such as furnace black, channel black, and acetylene black, various carbon fibers such as pitch-based, polyacrylonitrile (PAN) -based, and phenol resin-based, and various types such as graphite and coke. A carbon material, a conductive polymer such as potassium titanate whisker, zinc oxide whisker, graphite whisker, polyol, and polyether subjected to a conductive treatment can be used.

  In addition, the mixing ratio of the above-described rubbers, the thermoplastic elastomer, the thermoplastic resin, and the conductive material is appropriately set so that the above-described surface resistance value is achieved.

In the grounding method as described above, since the above-described conductor 2 is used, the charge charged on the object 1 can be removed smoothly. At the same time, the conductor 2 used here has a surface resistance limited to the range of 10 ⁵ to 10 ¹³ Ω, and thus does not function as an electromagnetic wave receiving or transmitting antenna. For this reason, this grounding method makes it difficult for the conductor 2 to be a source of electromagnetic noise, and can effectively avoid malfunctions such as electronic components.

Embodiment 2
With reference to FIG. 2, an embodiment of another grounding method according to the present invention will be described. This embodiment is a method in the case where the two objects 1 shown in the description of the first embodiment are grounded simultaneously. In this grounding method, as shown in FIG. 2, two objects 1 are connected to each other using the above-described conductor 2, and one object 1 is grounded using the same conductor 2.

  In such a grounding method according to the present embodiment, the conductor 2 is unlikely to be a source of electromagnetic noise as in the case of the first embodiment. Further, in this embodiment, since the two objects 1 are grounded while being connected, the charge removal from the object 1 can be further facilitated, and at the same time, the generation of electromagnetic noise from the conductor 2 is more effective. Can be suppressed.

  In addition, this grounding method can be similarly implemented also when the object 1 is three or more.

Embodiment 3
With reference to FIG. 3, a pachinko machine as an embodiment of the electronic apparatus according to the present invention will be described. In the figure, a pachinko machine 10 includes a storage tank 11 for storing pachinko balls (an example of an independent metal member), a counter 12 for counting the number of balls output from the pachinko machine 10, and from the storage tank 11 to the counter 12. A rail 13 for supplying pachinko balls (an example of a member for moving a metal member in the space), and a control unit 14 for controlling the operation of each part of the pachinko machine 10 including the counter 12 I have. For the sake of understanding, the detailed configuration inside the pachinko machine 10 is omitted in FIG.

  In such a pachinko machine 10, the storage tank 11 and the rail 13 are members configured using an insulating material such as resin, for example. The counter 12 is an electrical component that includes various electrical elements. Further, the control unit 14 is an electronic component that incorporates an IC, LSI, or the like.

  In the pachinko machine 10, a member group excluding the control unit 14, such as the storage tank 11, the counter 12, and the rail 13, is grounded by the conductor 2 having one end connected to the storage tank 11. On the other hand, the control unit 14 is grounded using the conductor 2 independently of the member group. The conductor 2 used here is the same as that described in the first embodiment.

In the pachinko machine 10 described above, since the group of members such as the storage tank 11 and the control unit 14 are grounded, the charges charged in these can be removed smoothly. At the same time, since the conductor 2 used for grounding here has a surface resistance limited to the range of 10 ⁵ to 10 ¹³ Ω as described above, it functions as an antenna for receiving or transmitting electromagnetic waves. Hard to be a source of electromagnetic noise. For example, when the pachinko balls in the storage tank 11 flow through the rails 13 and are supplied to the counter 12, the rails 13 are made of an insulating member and thus are easily charged with static electricity. Even when the pachinko ball charged in the vicinity approaches or conducts the conductor 2, the conductor 2 hardly generates pulsed electromagnetic waves. For this reason, this pachinko machine 10 is unlikely to cause malfunction of the control unit 14.

  In the pachinko machine 10 described above, at least a part between the members constituting the above-described member group, for example, between the storage tank 11 and the rail 13 or between the storage tank 11 and the counter 12 is the conductor 2. It may be connected using. In this case, the electric charge charged in the member group excluding the control unit 14 can be more effectively removed, and at the same time, the generation of electromagnetic noise from the conductor 2 can be more effectively suppressed.

  Further, in the pachinko machine 10 described above, both the above-described member group and the control unit 14 are grounded, but only one of the member group or the control unit 14 can be grounded. Further, only some members of the member group can be grounded.

  Furthermore, in this embodiment, a pachinko machine has been described as an example. However, the present invention is also a member for moving an independent metal member such as a metal ball or a coin in a space (inside the apparatus) other than the pachinko machine. For example, the present invention can be similarly applied to an electronic device (for example, a gaming machine such as a throttle machine) including an insulating member or a group of members including a mechanism and an electronic component.

Example 1
100.00 parts by weight of styrene-butadiene copolymer rubber (trade name “SBR1502” manufactured by Nippon Zeon Co., Ltd.), 3.00 parts by weight of zinc oxide, 1.75 parts by weight of sulfur, 1.00 parts by weight of stearic acid, and additive 1.00 part by weight of a sulfur accelerator was blended, and high wear-resistant carbon black (particle size = 40 nm, specific surface area = 80 m ² / g) was added so as to be 30% by weight of the total weight. This mixture was roll-kneaded to form a plate-like material, and a linear conductor having a width of 3 mm, a thickness of 3 mm, and a length of 20 cm was cut out from the obtained plate-like material.

  One end of the obtained conductor was attached to the storage tank 11 of the pachinko machine 10 described in the third embodiment, and the other end of the conductor was connected to an iron wire and grounded. In this state, a large number of pachinko balls (made of chrome-plated iron) are flowed from the storage tank 11 to the counter 12 via the rails 13, and from the conductor using an EMI locator (manufactured by Sanki Electronics Co., Ltd.). The generation of pulsed electromagnetic waves was investigated. At this time, the sensitivity of the EMI locator was set to “low” (sensitivity = 5 mV, 74 dB), and the frequency of pulsed electromagnetic waves generated per minute was measured. Further, the conductor was cut to a length of 1 cm, silver electrodes were formed at both ends thereof, and the surface resistance of the conductor was measured according to the method described above. The results are shown in Table 1.

Example 2
Instead of adding 30% by weight of high wear-resistant carbon black, 20% by weight of high wear-resistant carbon black similar to that used in Example 1 and pitch-based carbon fiber (trade name of Donac Co., Ltd.) Except for the addition of 10% by weight of DonaCarbo S-244 "), the frequency of generation of pulsed electromagnetic waves and the surface resistance of the conductor were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3
13% by weight of pitch-based carbon fiber (trade name “Donna Carbo S-244” manufactured by Donac Co., Ltd.) is added to polypropylene resin (trade name “BC3B” manufactured by Nippon Polychem Co., Ltd.), and the mixture is extruded and kneaded. A 1 m long strand was obtained. This strand was used in place of the conductor used in Example 1, and the frequency of occurrence of pulsed electromagnetic waves and the surface resistance of the strand were measured in the same manner as in Example 1 except for that. The results are shown in Table 1.

Example 4
12% by weight of an antistatic polyether (trade name “Pelestat” manufactured by Sanyo Kasei Co., Ltd.) added to acrylonitrile-butadiene-styrene copolymer resin (trade name “KR2870” manufactured by Basff Engineering Plastics) Thus, a strand having a diameter of 3 mm and a length of 1 m was obtained. This strand was used in place of the conductor used in Example 1, and the frequency of occurrence of pulsed electromagnetic waves and the surface resistance of the strand were measured in the same manner as in Example 1 except for that. The results are shown in Table 1.

Comparative Example 1
An iron wire was used instead of the conductor used in Example 1, and the frequency of generation of pulsed electromagnetic waves and the surface resistance of the iron wire were measured in the same manner as in Example 1 except for that. The results are shown in Table 1.

Comparative Example 2
Polyacrylonitrile-based carbon fiber (trade name “Torayca T-300” manufactured by Toray Industries, Inc.) 30% by weight was added to polypropylene resin (trade name “BC3B” manufactured by Nippon Polychem Co., Ltd.), extruded and kneaded, and 3 mm in diameter. A strand having a length of 1 m was obtained. This strand was used in place of the conductor used in Example 1, and the frequency of occurrence of pulsed electromagnetic waves and the surface resistance of the strand were measured in the same manner as in Example 1 except for that. The results are shown in Table 1.

The figure which shows the grounding method which concerns on Embodiment 1 of this invention. The figure which shows the grounding method which concerns on Embodiment 2 of this invention. Schematic of the electronic device which concerns on Embodiment 3 of this invention.

Explanation of symbols

1 Object 2 Conductor

Claims (1)

A method for grounding a plurality of objects that can be charged,
Using a conductor having a surface resistance of 10 ⁵ to 10 ¹³ Ω for grounding while connecting the plurality of objects;
Grounding method.

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