JP2638260B2 - Heating equipment for paint - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a paint heating device used in a paint supply device.

(Prior art) A high-viscosity paint such as a vinyl chloride resin applied to the floor of an automobile or a sealing material applied to a joint between panels is usually applied to a vehicle body by airless coating. The system is generally configured as shown in FIG.

That is, the high-viscosity paint is supplied from a paint supply source 1 installed in a paint preparation chamber through a paint pipe 2 by a pressure pump (not shown), and is further pressurized by a pressure intensifier 3 to a predetermined application pressure. Since the viscosity of this high-viscosity paint such as vinyl chloride resin significantly changes depending on the temperature, thereby affecting the pattern width and discharge amount of the paint gun, the paint pipe 4 downstream of the pressure intensifier 3 is provided with a predetermined viscosity. Is provided with a heat exchanger 5 for heating the paint to the above temperature. As a heat exchanger for heating paint in winter or the like, a jacket type heat exchanger for supplying hot water is widely used, and the paint heated by this heat exchanger is further guided to a paint gun 7 through a paint pipe 6. . Paint piping 6 from the heat exchanger 5 to the painting gun 7
A heat insulating material 8 is wound on the outer peripheral surface of the heat exchanger 5, and is guided to the coating gun 7 while maintaining the temperature of the paint heated by the heat exchanger 5 as much as possible. The coating gun 7 shown in FIG. 4 is attached to a coating robot 9 for applying the vehicle body B.

(Problems to be Solved by the Invention) However, in the conventional paint heating apparatus, the paint heated in the heat exchanger 5 is heated in the paint pipe 6 after the heat exchanger. Although a certain degree of temperature drop can be prevented by this, the temperature drop until reaching the coating gun 7 cannot be escaped, and it remains in the paint pipe 6 when the production line is restarted after a lunch break or a holiday. There has been a problem that the temperature of the coating material decreases and the coating pattern does not spread. That is, when the temperature of the coating material decreases, the viscosity of the coating material increases, thereby reducing the pattern width determined by the type of gun tip at the tip of the coating gun.

Therefore, when the line is restarted, the paint remaining in the paint pipe 6 is discarded, the newly heated paint is guided to the painting gun 7, and the paint is sprayed on the vehicle body B. The problem of the pattern failure due to such a decrease in the paint temperature is not limited to the time when the line is restarted, and the same can be said during the line operation.

Although it was considered to provide a tape heater or the like in the paint pipe 6, it is necessary to configure the entire heating device to be explosion-proof in the coating booth from the viewpoint of fire prevention measures. Conventionally, measures have been taken by disposing of the paint described above because the cost increases.

The present invention has been made in view of such problems of the prior art, and can control the temperature of the paint discharged from the coating gun to a predetermined temperature, and can add paint that does not require fire prevention measures. It is intended to provide a heating device.

(Means for Solving the Problems) In order to achieve the above object, a paint heating apparatus according to the present invention provides a paint pipe between a paint supply source and a paint gun, and feeds paint in the middle of the paint pipe. In a paint supply device having a pressure feeding device and a heat exchanger that heats the paint to a predetermined temperature, an outer circumference of a paint pipe connecting the heat exchanger and a coating gun is covered with a pipe for air circulation, An air temperature sensor that supplies hot air adjusted to a predetermined temperature to the air circulation pipe and detects a temperature of hot air flowing through the air circulation pipe, and detects a paint temperature in the paint pipe. And a control means for controlling the temperature of the hot air based on data input from the two sensors.

At this time, an exhaust pipe is connected to the downstream side of the air circulation pipe via an on-off valve, and when the temperature detected by the paint temperature sensor or the air temperature sensor becomes equal to or higher than a predetermined value, the on-off valve is opened. It is preferable that the hot air in the air circulation pipe be opened to be discarded.

(Operation) In the present invention configured as described above, the high-viscosity paint is guided from the paint supply source to the heat exchanger, heated to a predetermined temperature, and then guided to the coating gun via the paint pipe. At this time, the paint heated to a predetermined temperature in the heat exchanger is maintained at the same temperature by hot air supplied from an air source via an air heater, and is applied under the initially set coating conditions. Becomes possible.

Also, even when the production line is stopped, the paint remaining in the paint pipe must be heated to an appropriate temperature by hot air controlled based on information from the paint temperature sensor and the air temperature sensor. Therefore, there is no possibility that a pattern defect due to a temperature drop will occur.

In addition, even if the paint line temperature rises to near the curing temperature for a long period of time while the production line is stopped for a long time, both sensors detect this and discard the hot air in the air circulation piping. Gelling can be prevented.

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

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a block diagram showing a control configuration of the embodiment. The heating device of the present embodiment was used as a supply device of a vinyl chloride plastisol applied to the floor of the floor of an automobile, a tire house, or the like, or a sealing material made of vinyl chloride applied to a joint of a vehicle body. Although described in a specific example, the present invention is not limited to this, and can be used for a general paint supply device.

First, as shown in FIG. 1, a high-viscosity paint is guided in a paint pipe 2 by a pressure feed pump (not shown) from a paint supply source 1 installed in a paint preparation chamber. Pressurized. This pressure intensifier 3 includes a coating gun 7
When the distance from the paint supply source 1 to the coating gun 7 is short, the pressure pump can be shared and omitted.

High-viscosity paints such as vinyl chloride resin change their viscosity significantly depending on the temperature.
Since it affects the discharge amount, the paint pipe 4 downstream of the pressure intensifier 3 is provided with a heat exchanger 5 for heating the paint to a predetermined temperature.
Is provided. As a heat exchanger for heating paint in winter or the like, a jacket type heat exchanger for supplying hot water is widely used, and the paint heated by this heat exchanger is further guided to a paint gun 7 through a paint pipe 6. . An outer circumference of a paint pipe 6 extending from the heat exchanger 5 to the coating gun 7 is covered with an air circulation pipe 10 to form a so-called double pipe structure as shown in a vertical sectional view of FIG. .

The high viscosity paint circulates in the paint pipe 6.
Heated and dehumidified air (hereinafter, referred to as hot air) is supplied from an air source 11 via an air heater 12 to a space between the air and the air circulation pipe 10. That is, air compressed to a predetermined pressure by an air source 11 composed of a device such as a compressor is guided to an air heater 12 by a pipe 13, where the air is heated to a predetermined temperature,
It is guided to the air circulation pipe 10 via the pipe 14. The air circulation pipe 10 is preferably provided in the entire region from the outlet of the heat exchanger 5 to the coating gun 7. When the coating pipe 6 is made of a flexible material such as a hose, the air circulation pipe 10 is provided. It is also preferable to be formed of a flexible material.

Further, in the heating device of the present embodiment, an exhaust pipe 16 is connected to the downstream side of the air circulation pipe 10 via a solenoid valve 15, and the air is opened when the solenoid valve 15 is opened. The hot air guided into the circulation pipe 10 can be discarded in a painting booth or the like.

Further, the air circulation pipe 10 is provided with an air temperature sensor 17 for detecting a temperature of hot air flowing through the air circulation pipe 10 and a paint temperature sensor 18 for detecting a paint temperature in the paint pipe 6. These two sensors
The information of 17 and 18 is input to the control means 19. (See FIG. 3). In the control means 19, a control signal is output to the air heater 12 based on the data input from the sensors 17 and 18 to control the temperature of the hot air, and the temperature detected by the sensors 17 and 18 is set to a predetermined value. When this is the case, the electromagnetic valve 15 is opened and the hot air in the air circulation pipe 10 is discarded. In other words, temperature control within the preset temperature range
Perform at 12, but if the paint temperature rises too close to the curing temperature of the paint, the gelation of the paint will proceed, so once the hot air in the air circulation pipe 10 is discarded, and the sharp rise in the paint temperature is prevented. Like that.

Although the coating gun 7 shown in FIG. 1 is attached to a coating robot 9 for coating the vehicle body B, the present invention can be applied regardless of the configuration of the coating apparatus. May be.

 Next, the operation will be described.

First, a high-viscosity paint is guided from a paint supply source 1 to a pressure intensifier 3 by a pressure pump, and is pressurized to a predetermined pressure by the pressure intensifier 3. This pressure is appropriately selected depending on the characteristics of the paint, the type of gun tip of the coating gun, and the like. The paint having a predetermined pressure is guided to a heat exchanger 5 via a paint pipe 4, heated to a predetermined temperature by heat exchange with hot water, and further guided to a coating gun 7 via a paint pipe 6. . At this time, the paint heated to a predetermined temperature in the heat exchanger 5 is kept at the same temperature by hot air supplied from the air source 11 via the air heater 12,
Coating under the initially set coating conditions becomes possible. Further, even when the production line is stopped, the paint remaining in the paint pipe 6 is heated to an appropriate temperature by hot air controlled based on information from the paint temperature sensor 18 and the air temperature sensor 17. Therefore, there is no possibility that a pattern defect due to a temperature drop will occur. In addition, even when the paint temperature rises to near the curing temperature for a long time during which the production line is stopped for a long time, both sensors 17 and 18 detect this and discard the hot air in the air circulation pipe 10. Therefore, gelling of the paint can be prevented.

As described above, according to the coating material heating apparatus of the present embodiment, the temperature of the coating material can be constantly maintained at a constant level, and it is possible to prevent the occurrence of a defective pattern and the occurrence of an uncoated portion due to a decrease in the discharge amount. Also, since the structure of the heating device is simple,
The equipment cost is low, and since there is no fire, there is no need for fire prevention measures. Further, it is not necessary to dispose of the paint, which is conventionally performed, which leads to a reduction in the amount of paint used.

(Effect of the Invention) As described above, according to the paint heating apparatus of the present invention,
The temperature of the paint can be always kept constant, and the occurrence of an uncoated portion due to a pattern defect and a decrease in the discharge amount can be prevented. In addition, since the structure of the heating device is simple, the equipment cost is low, and furthermore, since the structure does not use fire, there is no need for fire prevention measures. Further, it is not necessary to dispose of the paint, which is conventionally performed, which leads to a reduction in the amount of paint used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is a sectional view taken along the line II-II of FIG. 3, FIG. 3 is a block diagram showing a control configuration of the embodiment, and FIG. 4 is a configuration diagram showing a conventional paint heating apparatus. 1 ... paint supply source, 2,4,6 ... paint pipe, 5 ... heat exchanger, 7 ... paint gun, 10 ... air circulation pipe, 11 ... air source, 12 ... air heater, 15: Solenoid valve (open / close valve), 16: Exhaust pipe, 17: Air temperature sensor, 18: Paint temperature sensor, 19: Control means.

Claims (2)

(57) [Claims] 1. A paint pipe is provided between a paint supply source and a coating gun, a pumping device for pumping paint in the middle of the paint pipe, and a heat exchanger for heating the paint to a predetermined temperature. In the paint supply device, the outer circumference of a paint pipe that connects the heat exchanger and the coating gun is covered with an air circulation pipe, and hot air adjusted to a predetermined temperature is supplied to the air circulation pipe,
An air temperature sensor that detects the temperature of hot air flowing through the air circulation pipe, and a paint temperature sensor that detects the temperature of paint in the paint pipe, wherein the hot air is detected by data input from both sensors And a control unit for controlling a temperature of the paint. 2. An exhaust pipe is connected to the downstream side of the air circulation pipe via an on-off valve, and when the temperature detected by the paint temperature sensor or the air temperature sensor becomes equal to or higher than a predetermined value, the exhaust pipe is opened and closed. 2. The hot air in the air circulation pipe is discarded by opening the valve.
The paint heating device according to the above.