JPS6262240B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a wind pipe for a coal mine that exhibits excellent antistatic properties. Conventionally, wind pipes for coal mines have been subject to serious problems such as explosions and fires caused by discharge due to the generation of static electricity. To prevent this, tarpaulins with antistatic treatment have been developed. For example, (1) Tarpaulin with an antistatic agent coated or printed on the surface of the sheet. (2) Tarpaulin with antistatic agent kneaded into resin. (3) Tarpaulin made of resin mixed with conductive material such as carbon black. (4) A tarpaulin that uses conductive material for the cloth material that is the base material of the sheet. have been considered and adopted. However, these tarpaulins had the following drawbacks. (1) A tarpaulin whose surface is coated or printed with an antistatic agent has a problem in that its antistatic effect deteriorates in a short period of time due to moisture or surface friction. (2) Tarpaulin with antistatic agent mixed into resin
Although the durability of tarpaulin (1) has been improved, the antistatic agent may be washed away when it comes into contact with water, such as for construction purposes, and the type and amount of antistatic agent added may vary greatly due to moldability. It is subject to certain restrictions and does not stain the surface. (3) Tarpaulin made by kneading a conductive material such as carbon black into resin requires a large amount of carbon black to be added, which not only sacrifices the strength of the resin, but also makes it expensive as it can only be made in black. It is. (4) Tarpaulins that use a conductive material as the base material of the sheet are not only very expensive, but also have no versatility because the cloth is special. It had the following drawbacks. Also, a tarpaulin with conductivity in the intermediate layer can be considered, but this has not been put to practical use because there is no suitable grounding method and it takes a lot of effort to ground it on site to eliminate sparks from the metal ring part. I couldn't get into it. In order to improve these shortcomings, the inventors of the present invention conducted extensive research and found that they used a tarpaulin with a conductive layer in the middle layer, and used a shape retainer of the wind pipe and a metal ring at the connecting part to conduct electricity and ground the tarpaulin. According to
There is no need for special grounding work on site during construction, and the wind pipe can be structurally grounded, and all parts such as the tarpaulin and metal ring that make up the wind pipe can be energized and grounded, making it extremely safe. The present invention has a high level of performance. That is, the present invention
A wind pipe that uses a conductive tarpaulin as an intermediate layer with an electrical resistance of 10 ⁸ Ω or less, (a) A portion of the metal ring 2 fixed to the wind pipe to maintain the cylindrical shape of the wind pipe. The structure is such that a conductive film is wound around a metal ring so as to be in contact with each other so that electricity is passed between the metal ring and the conductive film, and the conductive film and a conductive layer which is an intermediate layer of the tarpaulin are connected by conductive metal rivets. Alternatively, it has a structure in which the metal ring and the tarpaulin are also energized by connecting them with conductive threads. The structure of the part that is attached to the metal ring is such that the conductive films that are attached to the metal ring come in contact with each other and conduct electricity. The present invention relates to an antistatic wind pipe characterized by: In the tarpaulin used in the present invention, a conductive layer is provided by coating or printing a conductive paint containing highly conductive carbon black on a base fabric, and a resin such as polyvinyl chloride is coated on both the front and back sides with this conductive layer in between. Or a laminated tarpaulin with a resin layer, in which rod-shaped electrodes with a diameter of 1 m/m and a length of 1 cm are placed parallel to each other at a distance of 1 cm so as to contact the conductive layer constituting the intermediate layer of the tarpaulin. Use one whose value when placed and measured is 10 ⁸ Ω or less. However, although only using a conductive tarpaulin can prevent local charging, static electricity that has been charged throughout the wind pipe will be discharged from the surface of the tarpaulin, and this will not provide a sufficiently safe condition. Rather, when the entire wind pipe is charged, it becomes dielectric and the metal ring is charged, and the metal ring may be discharged, and the discharge energy at this time becomes extremely large, causing a greater disaster. In order to eliminate this charging phenomenon of the metal rings, the present invention adopts a structure in which each conductive metal ring and the conductive layer of the tarpaulin intermediate layer are electrically connected to each other, and an electric circuit is formed from this metal ring to ground. The method of contact energization between the conductive metal ring and the intermediate conductive layer of the tarpaulin in the present invention is as shown in ^FIG . A metal ring is attached with metal rivets 8 and/or conductive threads 9 so as to pass through each of the ring cover tarpaulin 7, the conductive film 6, and the wind pipe main body tarpaulin 4, sandwiching the conductive film 6 shown below. Wrap, secure, and energize each contact. In general, wind pipes are constructed in large numbers by fitting a metal ring 3, which is a connecting part of one wind pipe unit, into a metal ring 3', which is a connecting part of other wind pipe units, as shown in Fig. 1 in units of 5 to 10 m. They are connected and made into the required length for practical use. In this case, with the structure described above, each unit of the wind pipe main body can be grounded through the hanger 10 attached to the conductive metal ring part 2, but if the wind pipe of a specific unit Since there are cases where the grounding condition of the
It is necessary to have a structure in which the terminal 3' is also energized. For this reason, in the present invention, the structure of the connecting portions of each unit of the wind pipe main body is made as shown in FIGS. 3 and 4. That is, the structure of the connection part of the connecting part 3 that is fitted inside another wind pipe main body is such that the conductive film 6 that is wrapped around the metal ring 2' contacts the tarpaulin 4 of the wind pipe main body, as shown in FIG. The structure is such that the end is rolled up and folded back to come out of the wind pipe main body, and the metal rivet 8 and/or the conductive thread 9 are passed through all the folded parts of the tarpaulin 4 and the conductive film 6 and fastened. The connection part structure of the other connection part 3' of the wind pipe main body is the fourth
As shown in the figure, a conductive film 6 that is wrapped in contact with a metal ring 2' is wrapped around the end of the tarpaulin 4 of the wind pipe main body, and is folded back so as to come out inside the wind pipe main body to attach a metal rivet 8 and/or a conductive film 6. The structure is such that the elastic thread 9 is passed through all the folded parts of the tarpaulin 4 and the conductive film 6 and fastened. Therefore, when the units of the wind pipe main body are connected, the connection part with the structure shown in FIG. 3 and the connection part with the structure shown in FIG. It becomes possible to apply electricity. Even if the wind pipe main body having a connecting portion having such a structure is connected to an arbitrary length, the main body and the metal ring of all parts are connected by the conductive layer. Examples of the present invention are shown below. (Example) (1) As a tarpaulin with a conductive layer in the middle layer
100 parts by weight of vinyl chloride-acrylic copolymer resin and 100 parts by weight of highly conductive carbon black on a base fabric of 420D 6-nylon 20 pieces/inch x 20 pieces/inch.
The weight part of the paint was added to form a conductive resin layer with a thickness of 0.005 mm. A 0.2 mm thick soft polyvinyl chloride film was laminated on both sides of this conductive resin layer. The polyvinyl chloride film used was prepared with a composition of 100 PVC, 60 DOP, 2 stabilizers, 5 titanium oxide, and 10 Sb ₂ O ₃ . The tarpaulin made as described above was used as a tarpaulin for the wind pipe main body and ring cover. (2) Metal rings are made by forming iron round bars with a diameter of 10 m/m into rings with a diameter of 550 m/m, and metal rings are attached every 1000 m/m to the wind pipe body length 5500 m/m. Fixed. (However, the distance between the metal ring fixed to the end that is fitted inside the other wind pipe body and the adjacent metal ring was 500m/m.) (3) The conductive film is a soft chloride film with a thickness of 0.1m/m. A vinyl film containing 100 PVC, 50 DOP, 2 parts stabilizer, and 30 parts highly conductive carbon black was made into a film using a conventional method. (4) The metal rivets were made of iron and had a diameter of 5 m/m, and the sewing part was made of 3-strand polyester sewing thread of No. 20 thread. The above constitutes 1 of the wind pipe main body of the present invention.
When a unit was made and the electrical resistance value between each metal ring was measured, the following measured values were obtained.

[Table] Furthermore, we connected two units of this wind pipe body and measured the resistance between the metal rings at both ends.
It was 1.5×10 ⁷ Ω.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of one unit of the wind pipe main body. Figure 2 is an enlarged cross-sectional view of the metal ring fixed to the wind pipe body. FIG. 3 is an enlarged cross-sectional view of the fixing part of the metal ring that is fitted inside and becomes the part to be joined when the wind pipe bodies are connected at one end of one unit of the wind pipe bodies. FIG. 4 is an enlarged cross-sectional view of the metal ring fixing portion of the portion that is connected to cover the other end of the wind pipe main body when the wind pipe main body is connected at the other end. 1... 1 unit of the wind pipe main body, 2... Metal ring part, 3, 3'... End connecting part of the wind pipe main body, 4...
Tarpaulin having a conductive layer as an intermediate layer, 5... Conductive layer as an intermediate layer of tarpaulin, 6... Conductive film, 7... Tarpaulin for ring cover, 8...
Metal rivet, 9... Conductive thread, 10... Hanging hand.

Claims (1)

[Scope of Claims] 1. A wind pipe in which an electrically conductive tarpaulin is used as an intermediate layer having an electrical resistance of 10 ⁸ Ω or less, which includes: The structure of the part of the metal ring 2 fixed to the metal ring is such that a conductive film is wound around the metal ring so as to be in contact with the metal ring so that electricity is passed between the metal ring and the conductive film, and a conductive layer is an intermediate layer between the conductive film and the tarpaulin. It has a structure in which the metal ring and the tarpaulin are also energized by connecting them with conductive metal rivets or conductive threads. The structure of the part that fixes the metal ring 3' is such that the conductive films attached so as to be in contact with the metal ring contact each other and conduct electricity. An antistatic wind pipe characterized by being grounded by a metal ring.