JPS618169A - Heating method for coating resin - Google Patents

Abstract

PURPOSE:To facilitate the maintenance of a conveyor apparatus and to enable the long-term use thereof by permitting said conveyor apparatus to recircule only around a heating oven, by making it possible to pass a product through a heating space along with a hanger independently of the conveyor apparatus. CONSTITUTION:In coating a metal product with a resin, a heating oven 1, which has not only a product heating space 2 but also a product feed-in port 3 and a product feed-out part 4 both of which are positioned below said heating space 2, is provided and a conveyor apparatus 9 recirculating around the heating oven 1 is arranged. The product detached from said conveyor apparatus 9 is raised from the product feed-in inlet 3 and heated at predetermined temp. for a predetermined time while moved through the heating space 2 and the heated product is fallen to be fed out from the product feed-out port 4. That is, by making it possible to pass the product through the heating space 2 along with a hanger 11 independently of the conveyor apparatus 9, said conveyor apparatus 9 may be recirculated only around the heating oven 1 and the maintenance of the conveyor apparatus becomes easy and the long-term use thereof is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of effectively heating various metal products when coating the surfaces of the products with resin.

[Conventional technology]

The surfaces of various metal products used in everyday households such as kitchen utensils, daily household items, furniture, and electrical appliances, as well as guard rails, guard fences, and other metal products used in the industrial field, are coated with various colored resins. This makes the product beautiful, and also protects the material and provides anti-corrosion treatment.

To coat such metal products with resin, the product is heated at a predetermined temperature for a predetermined time in a heating furnace, and the heated product is immersed in a storage tank that stores powdered resin and taken out to remove the powder that adheres to the product surface. The resin is melted by the heat of the product itself to form a resin film, and the resin coating process is completed.

The above-mentioned heating furnace has a basic shape of a large metal box with a sealed top surface, and the entrance for the metal products to be heated and the exit for the metal products after heating are equipped with double doors or doors that can be raised or lowered. It is formed. The door is sealed during heating, and the door is fully opened when the product is brought into the heating furnace or taken out from the heating furnace.

Moreover, the loading inlet and the unloading outlet are located at the same height as the product heating space.

[Problem that the invention seeks to solve]

Therefore, since the door is fully opened each time a product is carried into the heating furnace or removed from the heating furnace, the high heat inside the heating furnace flows out to the outside, and at the same time, low-temperature outside air flows into the heating furnace. This causes a rapid temperature change within the heating furnace, and the temperature of the entire heating furnace temporarily decreases. For this reason, it takes more heat and time than necessary to raise the inside of the heating furnace to a predetermined temperature and heat the product, resulting in extremely low thermal efficiency and wasteful use of heat, which is uneconomical.

In particular, products to be coated with resin are suspended in multiple pieces at appropriate intervals from a chain conhair that circulates inside and outside the heating furnace, and are brought into the heating furnace at regular intervals, so the products are subject to temperature changes as described above. Temperature differences occur locally between each product and even within a single product itself, resulting in poor resin adhesion.

Furthermore, since the conveying device itself, such as a chain conveyor, passes through a heating furnace, it is severely damaged by the high heat, making maintenance inspections and parts replacement uneconomical.

[Means for solving problems]

In view of the various drawbacks of the conventional heating furnaces used for resin coating as described above, the present invention has been developed to allow products to be carried into the heating furnace and removed from the heating furnace without opening the space in which the products are heated inside the heating furnace to the outside. It is possible to carry out the product, and it can always be heated at a predetermined temperature depending on the size of the product, the thickness of the material, etc., and the temperature of the product is uniform.

For this reason, the product inlet and outlet are formed below the heating space, so that the product can be heated while moving above the heating space.

Further, the product conveyance device only circulates around the heating furnace, without passing through the heating furnace, and only the product passes through the heating space.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 indicates a metal box-shaped heating furnace used in the method of the present invention, with a sealed upper space serving as a heating space 2 for the product, and a product loading port 3 into the heating furnace 1. Product export port 4 from heating furnace 1 located symmetrically with this
An opening is formed below the heating space 2.

This heating furnace 1 may be designed and manufactured separately for small and large products, or may be manufactured in advance for only large products so that it can be used for both small and large products.

Although not shown in the drawings, the heating furnace 1 is stably supported at an appropriate height and spatial position by a plurality of supports.

Reference numeral 5 in the figure indicates guide rails, two of which are installed in parallel above the heating space 2 from the carry-in port 3 side to the carry-out port 4 side. Further, 6 is a known heating device using electricity, gas, etc. as a heat source, 7 is a pair of elevating devices with suitable mechanisms that face the product loading port 3 and can be moved in and out of the heating furnace 1, and 8 is a product loading port 4.
The lifting device 7.8 has the same mechanism as the lifting device 7, which is installed facing the elevator, and both lifting devices 7.8 can be raised and lowered in the range between the guide rail 5 from the lower side of the loading inlet 3 and the unloading outlet 4. ing.

As shown in FIG. 3, a conveying device 9 consisting of, for example, a chain conveyor circulates outside the heating furnace 1. In the illustration, circulation is possible along one side of the heating furnace 1.
However, the present invention is not limited to this (it may be configured to circulate around the heating furnace 1 in an elliptical H shape, for example). A known hanger 11 in the shape of a long frame from which a metal product 10 to be heated is hung is removably attached, and a constant distance is maintained between each hanger 11. 10 is a hanger 1 using wire, hook, etc.
1, and the two remain integral until the resin coating is completed.

Next, product heating will be explained.

When the product 10 is brought to a position facing the loading port 3 by the circulating movement of the conveyance device 9, the hanger 11 is removed from the conveyance device 9 with the product 10 suspended, and both sides of the hanger 11 are Place it on the lifting device 7. Lifting device 7
rises to the highest position, that is, the height position of the guide rail 5 and stops, and the hanger T11 is transferred onto the guide rail 5. In this case, although not shown, a pneumatic or hydraulic cylinder is installed outside the heating furnace 1, and a cylinder rod that can reciprocate inside and outside the heating furnace 1 moves the hanger 'J'1'-11 from the lifting device 7 onto the guide rail 5. All you have to do is move it horizontally.

When the hanger 11 is transferred from the lifting device 7 to the guide rail 5 in this way, the hanger 11 already on the guide rail 5 will move forward by the width of the newly added hanger 11.

Therefore, when a plurality of hangers 5 are placed on the entire length of the guide rail 5, the hanger 11 at the most advanced position may be pushed off the guide rail 5 and fall, but the lifting device 8 must be moved up to the guide rail 5 position in advance. If it is raised, the hanger 11 pushed out from the guide rail 5 will be placed on the hanger without receiving it. Then, by lowering the lifting device 8, the product 10 can be carried out from the outlet 4.

As mentioned above, the moving distance of the hanger 11 on the guide rail 5 is regulated by the width of the hanger 11, but as shown in FIG. For example, by determining the positional relationship between each hanger 11, it is possible to increase the distance during movement.

The product 10 moves forward in the heating space 2 while being suspended from the hanger 11, and after being heated to a predetermined temperature, it is supported by the lifting device 8 and lowered as described above. After the heated product 10 is taken out from the outlet 4, it is immersed in a powder resin storage tank and coated with resin. Alternatively, if a well-known storage tank 13 for storing powdered resin, which is normally placed underground, is installed so that it can be raised and lowered between the pair of lifting devices 8 and facing the product delivery port 4, it can be carried out using the lifting device 8. When lowering the product 10 to the position,
By raising the storage tank 13 in advance, the product 1
0 can be directly immersed in the powdered resin in the storage tank 13 while lowering it. If the storage tank 13 is lowered to a predetermined position underground after a certain period of time, the product 10 can be coated with resin while maintaining the heating temperature.

The product 10 with resin adhered to the surface is transferred from the lifting device 8 to the conveyor device 9 and cooled and dried, or the product 10 with the resin adhered in a molten state is sent into a secondary heating furnace and heated to a temperature lower than the primary heating temperature as in the past. The resin surface may be further made smooth by heating at a low temperature. In this case, a secondary heating furnace having the same structure as the above-mentioned primary heating furnace can be used.

The transfer of the product 10 from the conveyance device 9 to the lifting device 7 for heating the product 10, the transfer of the product 10 from the lifting device 8 to the conveying device 9 to carry out the heated product 10, etc. are performed manually by the worker. However, in order to prevent danger, an appropriate moving device is installed between the transport device 9 and the loading entrance 3 and the loading exit 4, and the hanger 11 is automatically removed from the transporting device 9 and moved to the loading entrance 3. Alternatively, the hanger 11 may be transferred to the lifting device 7, or the hanger 11 may be moved to the conveying device 9 without receiving it from the lifting device 8 on the side of the exit 4.

The guide rail 5 mentioned above is simply a hanger 11 in the illustration.
Although the hanger 11 is a rod-shaped body that is placed and supported, the hanger 11 is not limited to this, and in order to facilitate the forward movement of the hanger 11, a plurality of rollers may be installed in the longitudinal direction of the upper surface. The hanger 11 may be transported by a self-propelled chain conveyor.

The intermittent movement speed of the product 10 by the conveyance device 9, the lifting speed of both lifting devices 7.8 during the movement distance of the product on the guide rail 5,
By comprehensively determining the heating temperature, etc. in the heating space 2 based on the size of the product and the thickness of the material, and by linking everything to enable automatic processing, it is possible to always obtain a finished product with a constant resin coating treatment. I can do it.

〔Effect of the invention〕

In the present invention, as explained above, by locating the heating space 2 above the product loading port 3 and the product loading port 4, there is no need to open the heating space 2 to the outside when loading and unloading products. Therefore, the heating space 2 can always maintain a predetermined heating temperature to heat the product, and there is no unevenness in product temperature, resin adhesion is uniform, and high-quality processed products can be provided.

In addition, since the product can pass through the heating space together with the hanger independently of the conveying device, the conveying device only needs to circulate around the heating furnace, making maintenance of the conveying device easy and long-term use. is possible.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view of the entire heating furnace, Fig. 2 is a schematic vertical sectional view of the central part showing the state of use, and Fig. 3 is a plan view of the heating furnace in section. , FIG. 4 is a perspective view of the hanger on which the product is hung. 1 is a heating furnace, 2 is a heating space, 3 is a product entrance, 4 is a product exit, 5 is a guide rail, 6 is a heating device, 7.8 is a lifting device, 9 is a conveyance device, 10 is a product, 11 is It's a hanger.

Claims (1)

[Claims] In the resin coating of metal products, the product is removed from the conveying device 9 that circulates around the heating furnace 1, which has a heating space 2 for the product, a product inlet 3 located below the heating space 2, and a product outlet 4. For resin coating, the product is raised from a product loading port 3, heated at a predetermined temperature for a predetermined period of time while moving within a heating space 2, and then the heated product can be lowered and carried out from a product loading port 4. Heating method.