JP4266775B2 - Telescopic duct - Google Patents

Description

  The present invention relates to a telescopic duct for pneumatic transportation.

  At least two pipes with different diameters are slidably fitted into a large-diameter pipe so that loose particles such as particles and chips can be pneumatically transported by the airflow flowing through the pipe. There is a telescopic duct that is inserted and stretchably connected. As means for generating a transport air flow in the pipe, there are one using an air discharge means and one using an air suction means.

  In such a duct for air transportation, when the transport air flow is generated by the air discharge means, the air pressure in the duct becomes higher than the atmospheric pressure, and when it is generated by the air suction means, the air pressure in the duct is high. It becomes lower than the atmospheric pressure, and an atmospheric pressure difference occurs inside and outside the duct. For this reason, in a telescopic duct, it is necessary to seal the connection part of a pipe | tube so that air may penetrate | invade from a connection part of a pipe | tube, or it may leak and transportation efficiency may not fall.

  As a sealing means for the pipe connecting portion in the telescopic duct, an O-ring, a gland packing, a lip seal is used as a sealing member for sealing between the connecting end of the large diameter side pipe and the outer peripheral surface of the small diameter side pipe. Etc. are often used (see, for example, Patent Document 1). These sealing members need to be pressed against the outer peripheral surface of the small-diameter side pipe by forcible compression means or pressing means to ensure sealing performance.

  In addition, as a telescopic duct that secures the sealing performance of the pipe connection without using a compulsory sealing member compression means or pressing means, when the transport air flow is generated by the air suction means, the pressure difference between the inside and outside of the duct Thus, when a substantially cylindrical sheet-like seal member provided at one end of the large-diameter side tube is brought into close contact with the outer peripheral surface of the small-diameter side tube and the transport air flow is generated by the air discharge means, There is also one in which a substantially cylindrical sheet-like sealing member provided at one end is brought into close contact with the inner peripheral surface of a large-diameter pipe (see, for example, Patent Document 2).

Japanese Utility Model Publication No. 56-64924 (page 3, Fig. 2-3) JP 2001-122435 A (page 2-4, FIG. 2-6)

  As in the telescopic duct described in Patent Document 1, a seal member such as an O-ring is pressed against the outer peripheral surface of the small-diameter side pipe to seal it. Any of the means can cope with the same configuration, but the seal member is pressed against the outer peripheral surface of the small-diameter side tube that slides when the duct is expanded and contracted with a large contact pressure by a forced compression means or pressing means. Further, there is a problem that the seal member is easily worn and the period during which the sealing property can be secured is short.

  Also, during expansion and contraction of the duct and pneumatic transportation, the duct is swayed and tends to cause eccentricity between the large-diameter side and the small-diameter side pipe. When such eccentricity occurs, the contact pressure of the seal member is uneven in the circumferential direction. Thus, there is also a problem that uneven wear occurs in the seal member.

  On the other hand, as in the telescopic duct described in Patent Document 2, a substantially cylindrical sheet-like sealing member that is brought into close contact with the peripheral surface of the pipe by the pressure difference between the inside and outside of the duct is a flexible rubber or plastic sheet. The seal member formed in the above is in close contact with the peripheral surface of the pipe only during pneumatic transportation, and is not in close contact with the peripheral surface of the pipe during expansion and contraction of the duct, which is often performed by stopping air transportation. it can. However, such a flexible sheet-shaped sealing member is liable to cause cracks or the like due to contact with other objects, and has a problem that the sealing performance is suddenly lowered.

  Further, the mounting portion of the substantially cylindrical sheet-like seal member differs depending on the transport air flow generation means. For example, the air flow generation means is switched between the air discharge means and the air suction means to perform two-way pneumatic transport. Cannot be used for telescopic ducts such as Further, when the air flow generating means is an air discharge means, it is necessary to attach a sheet-like sealing member to the inner peripheral side of the duct. More likely to occur.

  Accordingly, an object of the present invention is to provide a telescopic duct that can ensure a good sealability of a pipe connecting portion for a long period of time regardless of the means for generating the transport air flow.

In order to solve the above-described problems, the present invention connects at least two tubes having different diameters so that a small-diameter side tube can be slidably inserted into a large-diameter side tube, and can be expanded and contracted. In the telescopic duct that generates air flow by air discharge means or air suction means and transports the air in the pipe connected to the pipe, the outer circumference of the small-diameter side pipe inserted into the connecting end of the large-diameter side pipe A seal housing portion is provided between the two ring portions that are inwardly surrounded and spaced apart in the axial direction, and the seal member housed in the seal housing portion is connected to the small-diameter side tube. The ring-shaped sealing member has an inner peripheral surface that is slidably contacted in parallel with the outer peripheral surface of the ring, and is slidable between the two ring portions . High and low relative to atmospheric pressure Slide the contact direction in close contact with the inner surface of the ring portion which is determined by the body, either allowed one in close contact with the inner surface of the ring portion, and employs a configuration that seals the connecting portion of the two tubes.

  That is, a seal that accommodates a seal member between two ring portions that are opened inwardly around the outer periphery of a small-diameter side tube to be inserted into the connecting end portion of the large-diameter side tube and spaced apart in the axial direction. A storage part is provided, and the seal member stored in the seal storage part has an inner peripheral surface that slides in parallel with the outer peripheral surface of the small-diameter side pipe, and has a ring shape that is slidable between two ring parts. The ring-shaped seal member is slid by the pressure difference between the inside and outside of the duct and is brought into close contact with the inner side surface of either one of the ring portions, so that the small diameter of the seal member is obtained regardless of the means for generating the transport air flow. This eliminates the need to forcibly press the outer peripheral surface of the pipe on the side, prevents wear during expansion and contraction of the duct of the seal member, and uneven wear due to eccentricity of the large and small diameter pipes, and seals the pipe joints To ensure good long-term performance It was. When the transport air flow generating means is an air discharge means, the seal member is in close contact with the ring portion on the small diameter tube side, and when the air suction means is used, the seal member is in close contact with the ring portion on the large diameter tube side.

  By forming a surface parallel to the inner surface of the ring portion on the side to be in close contact with the end surface of the ring-shaped seal member on the side to be in close contact with the inner surface of the ring portion, the area of the seal surface is increased. The sealing property can be further improved.

  By inclining the inner surface of the ring part to which the seal member is intimately inward, the wedge effect of the inclined inner surface is pressed against the outer peripheral surface of the small-diameter side pipe to further improve the sealing performance. Can be improved.

  When the ring-shaped seal member slides in either direction, the means for generating the transport air flow is switched between the air discharge means and the air suction means by closely contacting the inner surface of one of the ring portions. Can be possible.

  The telescopic duct according to the present invention has an inward opening around the outer periphery of the small-diameter pipe to be inserted into the connecting end of the large-diameter pipe, and between two ring parts spaced apart in the axial direction. A seal housing part is provided for housing the seal member. The seal member housed in the seal housing part has an inner peripheral surface that slides in parallel with the outer peripheral surface of the small-diameter side tube, and is slidable between two ring parts. Since this ring-shaped seal member is slid by the pressure difference between the inside and outside of the duct so as to be in close contact with the inner side surface of one of the ring parts, it is possible to Regardless of this, there is no need to forcibly press the outer peripheral surface of the pipe on the small diameter side of the seal member, and wear during expansion and contraction of the duct of the seal member and uneven wear due to eccentricity of the large and small diameter pipes are eliminated. Prevents and improves the sealing performance of the connecting part for a long time It can be coercive.

  By forming a surface parallel to the inner side surface of the ring part on the side to be in close contact with the end surface on the side to be in close contact with the inner side surface of the ring part of the ring-shaped seal member, the area of the seal surface is increased, Sealability can be further improved.

  By inclining the inner surface of the ring part to which the seal member is intimately inward, the wedge effect of the inclined inner surface is pressed against the outer peripheral surface of the small-diameter side pipe to further improve the sealing performance. Can be improved.

  When the ring-shaped seal member slides in either direction, the means for generating the transport air flow can be switched between the air discharge means and the air suction means by closely contacting the inner surface of one of the ring portions. It can be.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the telescopic duct 1 is expanded and contracted by inserting a plurality of tubes having different diameters into a large-diameter tube 2a having a larger diameter so that the smaller-diameter tube 2b having a smaller diameter can be slid. These are connected to each other, and a transport air flow is generated in each of the pipes 2a and 2b connected to be extendable and contracted to pneumatically transport the bulk material. A small diameter pipe is connected to a connecting end of the large diameter pipe 2a. A seal storage portion 5 is provided between the two ring portions 3a and 3b, which are opened inwardly around the outer periphery of 2b and spaced apart in the axial direction, and the seal member 4 serves as a duct. It slides due to the pressure difference between the inside and outside and is in close contact with any one of the ring portions 3a, 3b, so that the connecting portions of the tubes 2a, 2b are sealed.

  Although not shown, one end of the telescopic duct is connected to an air suction means such as a vacuum generation source for generating a transport air flow or an air discharge means such as a blower. The bulk material can be pneumatically transported in both directions. When the air suction means is connected, as shown in FIG. 2 (a), the air pressure in the duct becomes lower than the atmospheric pressure, and the seal member 4 is in close contact with the ring portion 3a on the large diameter pipe 2a side, When the air discharge means is connected, as shown in FIG. 2B, the air pressure in the duct becomes higher than the atmospheric pressure, and the seal member 4 comes into close contact with the ring portion 3b on the small diameter tube 2b side. The contact direction of the seal member 4 is determined only by the level of the atmospheric pressure in the duct with respect to the atmospheric pressure, and is independent of the direction of pneumatic transportation.

  The opposing inner side surfaces of the two ring portions 3a and 3b are formed at right angles to the outer peripheral surface of the small diameter tube 2b, and the ring-shaped seal member 4 slidably in contact with the outer peripheral surface of the small diameter tube 2b has a rectangular cross section. Both end surfaces are formed in parallel with the inner side surfaces of the ring portions 3a and 3b, and the inner peripheral surface is formed in parallel with the outer peripheral surface of the small diameter tube 2b. Therefore, the space between the seal member 4 and the inner surface of each of the ring portions 3a and 3b and the outer peripheral surface of the small diameter tube 2b is well sealed with a wide seal surface. The seal member 4 is made of a normal sealing material such as hard rubber or plastic.

  3 and 4 show an air transportation device for cargo handling that employs the above-described telescopic ducts 1a, 1b, and 1c. In this pneumatic transport device, a child carriage 13 that traverses in the width direction is mounted on a parent carriage 12 that travels in the longitudinal direction on the ceiling of the storage 11 of the bulk material A. The telescopic duct 1a is suspended. The base end side of each telescopic duct 1a is connected to the telescopic duct 1b that expands and contracts in the transverse direction of the slave carriage 13 via the two cyclones 14 and the connecting duct 15 on the slave carriage 13, and further, the telescopic duct 1b. The base end side of 1b is connected to an extendable duct 1c that expands and contracts in the traveling direction of the main carriage 12.

  Although illustration is omitted, an air suction means is connected to the base end side of the telescopic duct 1c, and an air flow toward the base end side is generated in each telescopic duct 1a, 1b, 1c. Due to this air flow, the bulk material A in the storage 11 is pneumatically transported through the telescopic duct 1 a and falls into the cyclone 14. The loose material A falling into each cyclone 14 is discharged onto the belt conveyor 17 disposed on the parent carriage 12 through the hole 16 provided in the child carriage 13 and conveyed outside the storage 11. This pneumatic transport device can also connect a hopper and air discharge means to the base end side of the telescopic duct 1c, and put it into the hopper by directly connecting the connecting duct 15 to the base end side of each telescopic duct 1a. It is also possible to pneumatically transport the bulk material A to be stored in the storage 11.

  FIG. 5 shows a second embodiment. The basic structure of the telescopic duct 1 is the same as that of the first embodiment, and the inner side surfaces of the two ring portions 3a and 3b of the seal housing portion 5 are inclined inward from each other, and are ring-shaped. The seal member 4 is different in that it is formed in a trapezoidal cross section having an inclined surface equal to the inclination angle of the inner surface. In this embodiment, the seal member 4 that is in close contact with the inner inclined surfaces of the ring portions 3a and 3b is pressed against the outer peripheral surface of the small-diameter tube 2b by the wedge effect, and the inner peripheral surface that is in sliding contact with the outer peripheral surface of the small-diameter tube 2b is Since it is wide at the bottom of the trapezoid, the sealing performance is further improved.

  FIG. 6 shows a third embodiment. The telescopic duct 1 generates a transport air flow by only air suction means and transports it in one direction. The telescopic duct 1 is on the large-diameter pipe 2a side where the seal member 4 is in close contact with the air pressure in the duct lower than the atmosphere. Only the inner surface of the ring portion 3a is inclined inward, and the seal member 4 is different in that it is formed in a trapezoidal cross section having an inclined surface equal to the inclined surface only on the side in close contact with the inclined inner surface. . Note that the ring portion 3b on the small diameter tube 2b side to which the seal member 4 does not adhere is formed with a large gap from the outer peripheral surface of the small diameter tube 2b so that the seal member 4 does not fall off.

  In each of the above-described embodiments, two pipes are connected so as to be expandable / contractable. However, the telescopic duct according to the present invention may be formed by connecting three or more pipes.

The principal part longitudinal section front view which shows the telescopic duct of 1st Embodiment a and b are enlarged sectional views for explaining the contact direction of the seal member in FIG. Longitudinal front view showing a pneumatic transport device employing the telescopic duct of FIG. 3 is a perspective view. Main part longitudinal front view which shows the telescopic duct of 2nd Embodiment The principal part vertical front view which shows the telescopic duct of 3rd Embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c Telescopic duct 2a, 2b Pipe 3a, 3b Ring part 4 Seal member 5 Seal storage part 11 Storage 12 Parent carriage 13 Sub-cart 14 Cyclone 15 Connection duct 16 Hole 17 Belt conveyor

Claims (4)

At least two pipes having different diameters are slidably inserted into a large-diameter pipe so that the small-diameter pipe can be slidably connected to each other. In the telescopic duct that generates air flow by air and transports by air, the connecting end portion of the large-diameter side tube opens inwardly around the outer periphery of the small-diameter side tube to be inserted, and is spaced in the axial direction. A seal housing portion is provided between the two ring portions having the openings, and the seal member housed in the seal housing portion has an inner peripheral surface that is slidably contacted in parallel with the outer peripheral surface of the small-diameter side pipe. The ring portion is slidable between the two ring portions, and the ring-shaped seal member is determined only by the level of the atmospheric pressure in the duct with respect to the atmospheric pressure due to the difference in pressure between the inside and outside of the telescopic duct. Inside surface Telescopic duct by sliding the contact direction of contact, either allowed one in close contact with the inner surface of the ring portion, characterized in that so as to seal the connection of the two tubes.   The telescopic duct according to claim 1, wherein a surface parallel to the inner side surface of the ring part on the side to be in close contact is formed on an end surface of the ring-shaped seal member on the side close to the inner side surface of the ring part.   The telescopic duct according to claim 1 or 2, wherein an inner side surface of the ring portion to which the seal member is in close contact is inclined inward.   When the ring-shaped seal member slides in any direction, the means for bringing the air flow into close contact with the inner surface of one of the ring portions can be switched between the air discharge means and the air suction means. The telescopic duct according to any one of claims 1 to 3.

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