JPH0699136A - Coating of inner surface of pipe - Google Patents

Abstract

PURPOSE:To obtain a uniform and smooth coating surface on the inner surface of a pipe. CONSTITUTION:A pipe 2 is heated to the curing temp. of a coating agent, 4, which is mixed with supplied air to be allowed to flow together with air and the coating agent 4 flowing along with the air stream is bonded to the inner surface of the heated pipe 2 to coat the inner surface of the pipe 2. Therefore, the inner surface of the pipe 2 can be coated within a short time without waste.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of coating the inner surface of a pipe such as an intake pipe used in an engine intake system for automobiles, motorcycles, outboard motors and the like.

[0002]

2. Description of the Related Art Conventionally, the inner surface of an intake pipe of an engine or the like is
It is smoothed by coating, which reduces intake resistance and improves engine output.

As a coating method for the inner surface of the intake pipe,
There are the following: That is, taking the intake manifold as an example, first, the coating resin (paint) is caused to flow into the intake manifold, and then it is blinded. In this state, the intake manifold is rotated and shaken so that the coating agent (coating resin) is sufficiently attached to the inner surface of the pipe, and then the excess coating agent is discharged to the outside. Next, when the coating agent attached to the inner surface of the pipe is heated and cured, the irregularities on the inner surface of the intake manifold (mostly made of aluminum) 51 are filled with the coating agent 52 and smoothed as shown in FIG.

[0004]

However, the above-mentioned conventional coating method has a drawback that it is not suitable for mass production because it has many steps and requires a long time for one step. Further, as compared with the coating agent 52 that actually adheres to the inner surface of the pipe, a larger amount of the coating agent 52 is discharged, so that the coating agent 52 is wasted and the cost is increased. Moreover, since it is difficult to coat with a uniform thickness by the conventional coating method, the reduction rate of the intake resistance is not so large.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a coating method for an inner surface of a pipe which can obtain a uniform and smooth coating surface.

[0006]

In order to solve the above-mentioned problems of the prior art, in the present invention, the tube is heated to the curing temperature of the coating agent and the coating agent is introduced into the air to be fed. The mixture is mixed and allowed to flow together with air, and the coating agent flowing along with the air flow is adhered to the inner surface of the heated pipe body for coating.

[0007]

In the coating method for the inner surface of the pipe according to the present invention, since the coating agent flowing along with the air flow is adhered to the inner surface of the heated pipe body, the coating can be performed in a short time and the coating can be performed. Less waste of agent. Moreover, since a uniform and smooth coating surface can be obtained, it is possible to greatly reduce the flow resistance of the fluid flowing inside the tubular body.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

1 to 3 show an embodiment of a method for coating the inner surface of a pipe according to the present invention. In the figure,
Reference numeral 1 is a coating facility for performing the coating method of the present embodiment, 2 is an aluminum alloy intake manifold of a tubular body to be coated, and 3 is an oven (heating furnace) that brings the manifold 2 to a preset temperature. When the coating agent (coating paint) 4 is a room temperature curing type epoxy resin, the temperature is 15 to 35 ° C. at room temperature, and when it is a baking type epoxy resin, it is 80 to
It is designed to be heated to a curing temperature of 120 ° C.

The coating equipment 1 is provided with a coating agent adjusting device 5, a mist discharge device 6, a coating agent cooling / separating device 7 and a suction device 8, and the respective devices are connected by pipe lines 9 to 13. There is. An aluminum alloy intake manifold 2 is arranged between the supply pipe 10 and the discharge pipe 11 at A.

That is, the adjusting device 5 and the discharge device 6 are connected via the connecting pipe line 9, and the discharge device 6 and the inlet 2a of the manifold 2 are connected via the supply pipe line 10. . The outlet 2b of the manifold 2 and the cooling / separating device 7 are connected via a discharge conduit 11, and the cooling / separating device 7 and the adjusting device 5 are connected via a recovery conduit 12. Further, the suction device 8 is connected to the discharge conduit 11 via the branch conduit 13. Since the supply pipeline 10 and the discharge pipeline 11 are connected to the manifold 2 as shown in FIG. 3, the supply pipeline 10 and the discharge pipeline 1 are connected.
1 is formed in a pipe shape, and one end of the discharge conduit 11 is formed in a manifold shape.

The discharging device 6 atomizes the coating agent 4 and mixes the atomized coating agent 4 into the air fed through the air passage 14 and discharges it into the supply pipeline 10. Device. Then, the air passage 14 is
One end is connected to the discharge device 6, and the other end is connected to a compression pump or the like (not shown).

The cooling / separating device 7 is a device for cooling the coating agent 4 whose temperature has been raised by passing through the heated manifold 2 and separating the coating agent 4 from air. The separated air passes through the air passage 15 and is discharged to an air supply source (not shown). Then, the air passage 15 is
One end is connected to the cooling / separating device 7, and the other end is connected to an air supply source or the like (not shown).

Further, the suction device 8 is provided with a supply line 10.
This is a device for sucking the coating agent 4 and the like through the branch pipe line 13 when the resistance A between the discharge pipe line 11 and the discharge pipe line 11 is large, and thereby smoothly and surely sending it to the cooling separation device 7. Normally, the coating agent 4 and the like do not pass through the branch passage 13 but are sent directly to the cooling / separating device 7 from the discharge pipe 11. In FIG. 1, 16 is a valve provided in the middle of the pipelines 9 and 10 and air passages 14 and 15, 17 is a cock provided at the connection point between the discharge pipeline 11 and the branch pipeline 13, and 18 Is a rotor provided in the adjusting device 5 for stirring the coating agent 4.

The coating method of the inner surface of the intake manifold 2 is as follows. First, the manifold 2 is placed in the oven 3 and the manifold 2 is preheated to the curing temperature of the coating agent 4. Then
The heated manifold 2 is arranged and attached to the space A between the supply pipeline 10 and the discharge pipeline 11 in the coating equipment 1.

In this state, the coating agent 4 adjusted by the adjusting device 5 is sent to the discharging device 6 through the connecting pipe line 9,
Atomizing coating agent is mixed into the air supplied to the discharging device 6 while being atomized by the discharging device 6, and it is made to flow into the supply pipeline 10 together with the air. Then, the mist-like coating agent 4 flows along the air flow as shown by the arrow in FIG. 3 and comes into contact with and adheres to the inner surface while passing through the tube of the heated manifold 2. The coating agent 4 adhering to the inner surface of the manifold 2 is cured to form a clean film (the inner surface is coated), so that the manifold 2 having a uniform inner tube surface and a smooth coating surface can be obtained.

A coating agent that has not adhered to the inner surface of the manifold 2 (that is, an extra coating agent) 4
Is sent to the cooling / separating device 7 together with the air flow via the discharge line 11 (or, further, the branch line 13 and the suction device 8). The coating agent 4 sent to the cooling / separating device 7 is separated from the air while being cooled, and is sent to the adjusting device 5 through the recovery pipeline 12 and is recovered. Then,
The extra coating agent 4 will be reused.

In this embodiment, since the atomized coating agent 4 is caused to flow inside the heating manifold 2 together with the air flow to adhere to the inner surface of the pipe, the coating process which conventionally required about 3 days takes about 15 minutes. It took only 30 seconds, and it became possible to coat in a short time. In addition, the coating method of the intake manifold 2 according to the present embodiment is the same as the conventional method because the flow of air during coating and the flow of intake air when actually installed in the engine are the same and match the usage conditions. It is possible to increase the reduction rate of the intake resistance compared to. Moreover, since the excess coating agent 4 is collected and reused, the waste of the coating agent can be greatly reduced.

The embodiment of the present invention has been described above.
The present invention is not limited to the embodiments described above, and various modifications can be made based on the technical idea of the present invention.

For example, if the intake manifold 2 in the above-described embodiment is grounded 19 as shown in FIG. 3 and charged positively (plus) and then the particles of the coating agent 4 are flown, the coating agent 4 can be more efficiently introduced into the pipe. It can be evenly attached to the surface. Further, in the above-described embodiment, the manifold 2 is heated in advance and attached to the coating equipment 1, but the conduit 1 attached to the manifold 2
Alternatively, 0 and 11 may be thermostatic chambers, and the coating agent 4 may be caused to flow while heating the manifold 2.
Furthermore, the present invention is applicable not only to the intake manifold 2 of an engine or the like, but also to a gas pipe for which flow resistance of a fluid is desired to be reduced,
It can also be applied to water pipes and the like.

[0021]

As described above, the method for coating the inner surface of the pipe according to the present invention heats the pipe body to the curing temperature of the coating agent and mixes the coating agent in the air to be fed together with the air. Since the coating agent flowing on the air flow is adhered to the inner surface of the heated pipe body for coating, a pipe body having a uniform and smooth coating surface can be obtained. The flow resistance of the fluid flowing inside the tube can be greatly reduced.
Therefore, when the coating method of the present invention is applied to the intake manifold, the coating airflow can be made to coincide with the flow of intake air, so that the reduction rate of intake resistance is larger than that of the conventional method, and the engine output is improved. It can be further improved.

Further, in the coating method of the present invention, since the coating agent is caused to flow on the air flow, the inner surface of the tubular body can be coated in a short time, and the working efficiency can be improved. Moreover, since the excess coating agent that does not adhere to the inner surface of the pipe can be easily collected, the waste of the coating agent is greatly reduced. Therefore, according to the coating method of the present invention, the manufacturing cost can be reduced, which is extremely economically advantageous.

Further, according to the coating method of the present invention, the film thickness (coating layer thickness) on the inner surface of the tube can be freely set by changing the coating time and the ratio of the coating agent to the diluent. It can be coated according to the requirements, and has excellent versatility.
Moreover, since the coating operation is simple and clean, the facility can be easily maintained and managed.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a coating facility for carrying out a method for coating a pipe inner surface according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an intake manifold arranged in an oven.

FIG. 3 is a perspective view showing the intake manifold being coated by the above coating method.

FIG. 4 is a cross-sectional view showing a coating agent attached to an intake manifold.

[Explanation of symbols] 1 coating equipment 2 intake manifold 3 oven 4 coating agent 5 coating agent adjusting device 6 mist discharge device 7 coating agent cooling / separating device 8 suction device 9 to 13 pipe lines 14 and 15 air passages

Claims (1)

[Claims] 1. A tube is heated to the curing temperature of the coating agent, and the coating agent is mixed in the air to be fed and allowed to flow together with the air. A coating method for an inner surface of a pipe, which is characterized in that it is attached to the inner surface of a heated pipe body for coating.