JP2013198832A - Coating apparatus of socket inner surface of cast iron pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely prevent a coating material from adhering to an inner surface of a straight part when a socket inner surface of a cast iron pipe is coated.SOLUTION: Air is supplied to an inside of a cast iron pipe 1 from a side of an inserting mouth 1c aiming at a side of a socket 1b using an air supply machine 50. A coating material sprayed on an inner surface of the socket by a wind pressure of the air is easily prevented from being dispersed to a side of a straight part 1a. The coating material does not adhere to a cast iron pipe 1 by mistake because coating apparatuses such as nozzles 20 and the air supply machine 50 do not contact to the cast iron pipe 1 physically.

Description

  The present invention relates to an apparatus for coating the inner surface of a receiving port of a cast iron pipe having a receiving port and an insertion port, and a method for coating the inner surface of the receiving port.

Cast iron pipes are buried in the soil and used for running water passages. The outer surface is protected from corrosion due to moisture in the soil, and the inner surface is protected from corrosion due to running water, etc. Or, cement lining is applied to the inner surface.
In such a cast iron pipe structure, a receiving port is provided at one end of the straight part and an insertion port is provided at the other end, and the cast iron pipe is sequentially connected by inserting an insertion port of another cast iron pipe into the receiving port of the cast iron pipe. Is common.

In this type of cast iron pipe, the inner surface of the receiving port has a groove for fitting a packing that enhances water tightness, etc., so that the unevenness is severe compared to the inner surface of the straight part and it is difficult to apply cement lining. .
Therefore, the cement lining is applied to the inner surface of only the direct part of the cast iron pipe, and the inner surface of the receiving port is provided with corrosion resistance by spraying a powder paint or the like separately.

  Here, when spraying the inner surface of the receiving port, it is not preferable that the coating material is scattered and adhered to the inner surface of the straight portion because the aesthetic appearance is impaired. Therefore, the Japan Ductile Iron Pipe Association (JDPA) also imposes strict coating standards.

Therefore, as one of the conventional solutions, as shown in FIG. 4, with the shielding plate P in contact with the step formed at the boundary between the inner surface of the straight portion 1a of the cast iron pipe 1 and the inner surface of the receiving port 1b. It is known that the nozzle 20 is inserted into a receiving port to coat the inner surface (Patent Document 1).
Thus, by performing masking with the shielding plate P, it is possible to suppress the paint from flowing into the inner surface of the straight portion 1a.

  However, if the shielding plate P is used repeatedly, the paint adheres to and accumulates on the shielding plate P, which may accidentally contaminate the inner surface of the straight part 1a. In order to prevent such contamination, the shielding plate It is troublesome to clean P every work.

JP-A-6-79206

  Therefore, the problem to be solved by the present invention is to easily and surely prevent the paint from adhering to the inner surface of the straight part when coating the inner surface of the receiving port of the cast iron pipe.

In order to solve the above-described problems, in the present invention, when a nozzle is inserted into the inner surface of the receiving port of the cast iron pipe and spray coating is performed, air is supplied from the insertion port side to the receiving port side inside the cast iron tube. It was.
Preferably, not only the inside of the cast iron pipe but also the outer surface thereof is supplied with air from the insertion port side toward the receiving port side.
More preferably, the air is supplied from outside the painting site.

Specifically, the coating device for the inner surface of the receiving port of the cast iron pipe of the present invention can be moved relative to the cast iron pipe in the direction of the pipe axis, and a support mechanism for supporting the cast iron pipe so as to be rotatable around the pipe axis. And a nozzle capable of spraying paint onto the inner surface of the receiving port by inserting it into the receiving port of the cast iron tube, and at least the inside of the cast iron tube from the insertion port side of the cast iron tube toward the receiving port side. It is set as the structure provided with the air supply machine which can supply the air which distribute | circulates.
Although the kind of air supply machine is not specifically limited here, A blower, a compressor, and a fan can be illustrated.

  Preferably, the coating apparatus further includes a flow dividing plate in which an insertion port of the cast iron pipe is inserted, and a blow hole having a diameter larger than the insertion port is formed, and the air supplied from the air supply unit is Through the blow-in hole of the plate, it is possible to circulate along the inside of the cast iron pipe and the outer surface of the cast iron pipe from the insertion port side of the cast iron tube toward the receiving port side.

  More preferably, the coating apparatus is provided with a coating booth in which the cast iron pipe, the support mechanism, and the nozzle are accommodated, an exhaust port at one end, and an intake port at the other end, and the exhaust port is provided in the coating booth. And a duct that is placed over the insertion port of the cast iron rod and the intake port is disposed outside the painting booth, and the air supply device is connected to the intake port of the duct outside the painting booth. The air outside the painting booth can be supplied to the cast iron pipe through the duct.

  In more detail, in the method of painting the inner surface of the receiving port of the cast iron pipe of the present invention, while rotating the cast iron tube around its tube axis, a nozzle is inserted into the receiving port, and the paint is applied from the nozzle toward the inner surface of the receiving port. The spraying step and the step of supplying air from the insertion port toward the receiving port at the same time as the inside of the cast iron pipe are configured.

  Preferably, the coating method preferably further includes a step of supplying air from the insertion port toward the receiving port along the outer surface of the cast iron pipe.

  More preferably, the coating method is such that the air in the step of supplying air is introduced from outside the system in the step of spraying the paint.

  By supplying air that circulates inside the cast iron pipe from the insertion port toward the receiving port, it is possible to easily prevent the paint sprayed on the inner surface of the receiving port from being scattered by the wind pressure. .

  Unlike the case of using a shielding plate, the coating apparatus does not physically contact the inner surface of the cast iron pipe, so that the paint deposited and deposited on the coating apparatus does not contaminate the inner surface of the cast iron pipe.

  By supplying air to the outer surface of the cast iron pipe from the insertion port toward the receiving port, it is possible to prevent the paint floating on the painting site from being introduced to the inner surface of the cast iron tube and sticking due to the wind pressure. it can.

  By supplying clean air from the outside of the painting site, it is possible to prevent unintentional introduction of the coating material inside the cast iron pipe, unlike the case of using painting site mixed air. This can more reliably prevent the paint from adhering to the inner surface of the straight part.

The side view of the coating device of the receiving port inner surface of the cast iron pipe of 1st Embodiment (A) is a perspective view of the nozzle vicinity part, (b) is a perspective view of a blower vicinity part of the coating apparatus of the receiving port inner surface of the cast iron pipe of 1st Embodiment. Side view of coating apparatus for inner surface of receiving port of cast iron pipe of second embodiment Side view of a conventional cast iron pipe interior coating device

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a coating apparatus according to the first embodiment. This coating apparatus is used for spray-coating the inner surface of the receiving port 1b for a general-purpose cast iron pipe 1 having a receiving port 1b and an insertion port 1c at both ends of the straight part 1a. The structure which prevents that a coating material adheres to the inner surface of the straight part 1a accidentally is employ | adopted.

  The coating apparatus includes a support mechanism 10 that supports the cast iron pipe 1, a nozzle 20 that performs spray coating, a duct 30 that serves as an air flow path, a flow dividing plate 40 that divides the air flowing through the duct 30, and a duct 30. A blower serving as an air supply machine 50 for supplying air and a painting booth 60 for partitioning a painting work site are provided.

As shown in the figure, the support mechanism 10 has a known structure including an elongated base 11 and roll portions 12 provided on the upper surfaces of both ends of the base 11 in the longitudinal direction.
Each roll part 12 is provided with a pair of turning rolls 12a and 12a arranged in parallel in the width direction (short direction) of the base, and by these turning rolls 12a and 12a, near both ends of the straight part 1a of the cast iron pipe 1 Are supported from below.
Since each of the turning rolls 12a and 12a is rotatable in the circumferential direction, the cast iron pipe 1 is supported and can be rotated around the pipe axis as shown by an arrow in FIG. Yes.

As shown in the figure, the nozzle 20 has a known structure capable of spraying paint that imparts corrosion resistance to the cast iron pipe 1, and is loaded on the coating carriage 21 and faces the receiving port 1 b of the cast iron pipe 1. ing.
As shown by the chain line in FIG. 1, the coating carriage 21 is movable in the direction of the pipe axis of the cast iron pipe 1, and the nozzle 20 loaded on the coating carriage 21 is also moved along the pipe axis of the cast iron pipe 1. It can move in the direction. Therefore, by moving the painting carriage 21 forward and backward, the nozzle 20 can be inserted into the receiving port 1b of the cast iron pipe 1 by a desired depth, or can be extracted from the receiving port 1b.

As shown in the figure, the duct 30 has a known structure in which an exhaust port is provided at one end and an intake port is provided at the other end so that air can be circulated therein. The duct 30 is supported by a holder 31 a on a blower carriage 31. The exhaust port faces the insertion port 1 c of the cast iron pipe 1.
A hood 32 is provided at the exhaust port of the duct 30, and the hood 32 is placed in the vicinity of the insertion port 1 c of the cast iron pipe 1.
As shown by a chain line in FIG. 1, the blower carriage 31 is movable in the tube axis direction of the cast iron pipe 1, and the hood 32 supported on the blower carriage 31 is also a pipe of the cast iron pipe 1. It can move in the axial direction. Therefore, the hood 32 can be put on or removed from the insertion opening 1c of the cast iron pipe 1 by moving the blowing carriage 31 forward and backward. The duct 30 is preferably formed of a flexible material so as to easily follow the advancement and retreat of the blower carriage 31.

As illustrated, the flow dividing plate 40 is attached to the opening of the hood 32 of the duct 30 by appropriate means such as screwing and fitting. The flow dividing plate 40 is provided with a circular blowing hole 41 penetrating in the thickness direction, and the diameter of the hole is larger than the pipe diameter (outer diameter) of the cast iron pipe 1.
With the hood 32 of the duct 30 covered on the cast iron pipe 1, the insertion port 1 c of the cast iron pipe 1 is inserted shallowly into the blow hole 41 of the flow dividing plate 40. In this inserted state, as can be seen from FIG. 2 (b), the support height of the duct 30 on the blower carriage 31 is such that the axis of the cast iron pipe 1 and the center of the circle of the blow hole 41 substantially coincide. It is assumed that etc. have been adjusted.
Due to the dimensional relationship and positional relationship between the blowing hole 41 and the insertion port 1c described above, an annular flow channel facing the outer surface of the cast iron pipe 1 is formed outside the central portion where the insertion port 1c of the blowing hole 41 is inserted. Will be.

As shown in the figure, the air supply machine 50 is a blower having a known structure capable of blowing air, and is connected to the intake port of the duct 30.
Thereby, the air supplied from the air supply device 50 is guided to the insertion port 1 c side of the cast iron pipe 1 through the duct 30. Further, the air flowing through the duct 30 passes from the insertion port 1c of the cast iron pipe 1 covered with the hood 32 to the inside of the reception port 1b through which the painting work is performed by the nozzle 20 through the inside of the cast iron pipe 1. 1 is supplied as indicated by the white arrow.
In addition, the air in the duct 30 is exhausted from the annular flow path of the blowing hole 41 of the flow dividing plate 40 attached to the opening of the hood 32, so that the exhausted air is cast iron pipe. 1 flows from the side of the insertion port 1c to the side of the receiving port 1b as shown by the white arrow in FIG.
In this way, the flow dividing plate 40 has an effect of diverting the air in the duct 30 into and out of the cast iron pipe 1.

Here, the hole diameter of the blow hole 41 of the flow dividing plate 40 is not limited as long as it is larger than the pipe diameter of the cast iron pipe 1, but if the hole diameter is too small, the width of the annular channel (in the radial direction of the ring) (Length) is reduced and the amount of air flowing to the outer surface of the cast iron pipe 1 is reduced.
On the other hand, if the hole diameter is too large, the width of the annular channel becomes large and air diffuses, making it difficult to flow along the outer surface of the cast iron pipe 1, and also flowing in the duct through the annular channel. There is a possibility that air in the painting booth 60 may be mixed into the air.
Furthermore, it is necessary to balance the amount of air flowing inside and outside the cast iron pipe 1 so as not to be extremely biased.
Therefore, it is preferable to adjust the hole diameter of the blow hole 41 in relation to the pipe diameter of the cast iron pipe 1 so that the width of the annular flow path is about 5 to 15 cm. For example, if the pipe diameter of the cast iron pipe 1 is 15 cm, the hole diameter is preferably about 25 to 45 cm.

Further, as shown in the drawing, the cast iron rod 1, the support mechanism 10, the nozzle 20, the place except the inlet of the duct 30 and the flow dividing plate 40 are accommodated in the painting booth 60 partitioned from the outside.
The structure and dimensions of the painting booth are not particularly limited as long as the painting operation of the cast iron pipe can be performed smoothly.
On the other hand, the intake port of the duct 30 is drawn out of the painting booth 60, and the air supply unit 50 is installed outside the painting booth and connected to the intake port.

The configuration of the coating apparatus according to the first embodiment is as described above. In the coating booth 60, while the cast iron pipe 1 on the support mechanism 10 is rotated in the direction of the pipe axis, the coating carriage 21 is advanced and the nozzle is moved forward. 20 is inserted into the receiving port 1b of the cast iron pipe 1, and paint is sprayed from the nozzle 20 toward the inner surface of the receiving port 1b, and the entire inner surface is painted.
At the same time or in advance, the blower carriage 31 is moved forward so that the hood 32 of the duct 30 is placed over the insertion opening 1 c of the cast iron pipe 1, and the insertion opening 1 c is inserted into the blowing hole 41 of the flow dividing plate 40. Furthermore, the blower as the air supply machine 50 outside the painting booth 60 is operated to circulate air from the insertion port 1c side to the receiving port 1b side along the inside and the outer surface of the cast iron pipe 1.

  Due to the wind pressure of the air flowing inside the cast iron pipe 1 toward the receiving port 1b, the paint for coating the inner surface of the receiving port 1b enters the straight portion 1a and is easily prevented from adhering to the inner surface of the straight portion 1a. Has been.

Furthermore, since the air circulated inside and outside the cast iron pipe 1 is clean air supplied from a blower as the air supply device 50 outside the painting booth 60, paint is mixed in unlike the atmosphere of the painting booth 60. Therefore, it is further prevented that the paint adheres to the inside and outside of the cast iron pipe 1 unintentionally.
Since the hood 32 is put on the insertion opening 1c of the cast iron rod 1 and air is guided from the duct 30, the atmosphere of the painting booth 60 is accompanied by the air in the duct 30 (an accompanying flow occurs), and the insertion opening 1c It is prevented from being drawn from the gap of the duct 30 into the cast iron pipe. Therefore, the paint floating in the painting booth 60 is further prevented from unintentionally adhering to the cast iron pipe 1.

FIG. 3 shows a coating apparatus according to the second embodiment. In this embodiment, a compressor as an air supply machine 50 is installed facing the insertion port 1c of the cast iron pipe 1, and directly inside the cast iron pipe 1 without passing through a duct. Air is blown by air blow as indicated by the white arrow in the figure.
Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted.
Since it is the structure which only installs the compressor as the air supply machine 50, a duct etc. like 1st Embodiment are not required, and it is very simple and is low-cost.

  It should be considered that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications and variations within the scope and meaning equivalent to the terms of the claims.

For example, the support mechanism 10 is not limited to the structure shown in the embodiment, and it suffices if it can support the cast iron rod 1 so as to be rotatable around its axis.
Further, in the embodiment, the nozzle 20 is mounted on the coating carriage 21 so as to be movable in the pipe axis direction of the cast iron pipe 1. However, if the nozzle 20 can move relatively in the pipe axis direction in relation to the cast iron pipe 1. That's enough. For example, the nozzle 20 may be fixed in a non-movable state, and the cast iron pipe 1 (and the support mechanism 10) may be mounted on the carriage and moved.
Similarly, in the embodiment, the duct 30 is supported by the blower carriage 31 so as to be movable, but may be fixed in an unmovable state.

Further, in the embodiment, the hood 32 and the flow dividing plate 40 are separated from each other, but may be integrally formed. The blowing holes 41 of the flow dividing plate 40 are not limited to circular holes, but may be elliptical holes, rectangular holes, polygonal holes, or the like. The case where the center of the blow hole 41 and the axial center of the cast iron pipe 1 substantially coincide with each other as in the embodiment is preferable because air flows evenly along substantially the entire circumference of the cast iron pipe 1. The axis does not necessarily need to coincide.
The painting booth 60 may be appropriately provided with ventilation means to facilitate the discharge of the air after being distributed along the cast iron pipe to the outside of the painting booth 60.
As the air supply device 50, the blower is illustrated in the first embodiment and the compressor is illustrated in the second embodiment, but other air supply devices such as a fan may be used instead.

DESCRIPTION OF SYMBOLS 1 Cast iron 1a Direct part 1b Receptacle 1c Insertion slot 10 Support mechanism 11 Base 12 Roll part 12a Turning roll 20 Nozzle 21 Coating cart 30 Duct 31 Blower cart 31a Holder 32 Hood 40 Diverging plate 41 Blow hole 50 Air supply machine 60 Painting booth P Shield plate

Claims (7)

An apparatus for spray-coating the inner surface of the receiving port of a cast iron rod having a receiving port at one end and an opening at the other end,
A support mechanism for rotatably supporting the cast iron pipe around its pipe axis;
A nozzle that is movable relative to the cast iron pipe in the axial direction of the cast iron and that can be inserted into a receiving port of the cast iron pipe and spray paint toward the inner surface of the receiving port;
From the insertion port side of the cast iron pipe toward the receiving side, an air supply machine capable of supplying at least air circulating through the cast iron pipe,
A coating device for the inner surface of a receiving port of a cast iron pipe. A flow dividing plate in which an insertion port of the cast iron pipe is inserted, and a blow hole having a larger diameter than the insertion port is formed;
The air supplied from the air supply machine can flow along the inside of the cast iron pipe and the outer surface of the cast iron pipe from the insertion hole side of the cast iron pipe to the receiving side through the blow hole of the flow dividing plate. The coating apparatus for the inner surface of the receiving port of the cast iron pipe according to claim 1. A paint booth in which the cast iron pipe, the support mechanism, and the nozzle are housed;
An exhaust port is provided at one end, an intake port is provided at the other end, the exhaust port is covered with an insertion port of the cast iron rod in the painting booth, and the intake port is disposed outside the painting booth; Further comprising
The said air supply machine is connected to the inlet of the said duct outside the said painting booth, and can supply the air outside the said painting booth toward the insertion port of the said cast iron pipe through the said duct. The coating apparatus of the inner surface of the receiving port of the cast iron pipe of 2.   The said air supply machine is either a blower, a compressor, or a fan, The coating device of the inner surface of the receiving opening of a cast iron pipe in any one of Claim 1 to 3. A method of spray-coating the inner surface of the receiving port of a cast iron rod having a receiving port at one end and an opening at the other end,
While rotating the cast iron pipe around its pipe axis, inserting a nozzle into the receptacle and spraying paint from the nozzle toward the inner surface of the receptacle;
And a step of supplying air into the cast iron pipe from the insertion port toward the receiving port at the same time.   The method for coating the inner surface of the receiving end of the cast iron pipe according to claim 5, further comprising a step of supplying air from the insertion port toward the receiving end side along the outer surface of the cast iron pipe.   The air in the step of supplying the air is introduced from the outside of the system in the step of spraying the paint.

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