JPH069806Y2 - Mold heating furnace - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to heating of a molding die, and particularly to a molding die for heating a die used for molding synthetic resin to a temperature suitable for molding. Type heating furnace.

[Prior Art] A conventional heating furnace for a molding die of this type has hot air burners, electric heaters, etc. arranged above, below, and laterally of the furnace,
A predetermined molding die was heated by circulating hot air having a predetermined temperature or higher in the furnace.

[Problems to be Solved by the Invention] In the conventional heating furnace for a molding die, a hot air burner, an electric heater, or the like is provided, and hot air having a temperature equal to or higher than a predetermined temperature is circulated in the furnace to achieve a predetermined molding. Since the mold is heated, the surface of the mold is directly heated, and a large temperature gradient is generated between the surface of the mold and the inside of the mold. There was a problem of shortening the life of the mold.

Further, since the temperature rise of the molding die is dependent on the heat conduction of the material forming the die, it takes a long time for the molding die to reach a desired temperature. Further, since the temperature rise of the molding die was entrusted to the heat conduction of the material forming the die,
There is a problem that the temperature distribution cannot be made uniform due to the difference in the thickness of the mold.

Therefore, the present invention has been made to solve the above-mentioned problems, that is, the temperature rising time of the molding die is fast, the temperature distribution of the molding die is uniform, and the distortion of the molding die is prevented. However, it is an object of the present invention to provide a molding furnace heating furnace having a long life.

[Means for Solving Problems] A heating furnace for a molding die according to the present invention is divided into a group of a plurality of control units in a furnace body that accommodates the molding die while being placed on a support member. A far infrared generator and a circulation fan for circulating the air in the furnace body are provided.

[Operation] In the heating furnace for the molding die of the present invention, the far-infrared ray generator is arranged in the furnace body by dividing it into a group of a plurality of control units. By heating a molding die from its inner surface and controlling the far-infrared ray generator by dividing it into groups of multiple control units, the radiant energy is determined in consideration of the wall thickness of the molding die. Therefore, the temperature distribution of the molding die can be made uniform.

Further, since the circulation fan that circulates the air in the furnace body is provided, it is possible to perform heating with warm air in the furnace body. Therefore, radiant energy from the far-infrared generator and warm air heating can be performed at the same time,
The time required for the molding die to reach the desired temperature can be shortened.

Further, the temperature distribution of the molding die is made uniform, so that the generation of thermal strain of the molding die can be prevented, and as a result, the life can be extended.

[Embodiment] An embodiment of the present invention will now be described.

FIG. 1 is a cross-sectional view of a molding die heating furnace of one embodiment of the present invention seen from the front, and FIG. 2 is a side view of the molding die heating furnace of one embodiment of the present invention shown in FIG. It is sectional drawing seen. Further, FIG. 3 is an explanatory view showing a cross section of the far infrared ray generator used in this embodiment, and FIG. 4 is an explanatory view showing a circuit of a gas supply line used in this embodiment.

In the figure, a furnace body 1 is a furnace body outer wall 1 that shuts off outside air.
a, and a furnace body inner wall 1b formed of a heat insulating material made of a material having high heat resistance and fire resistance for keeping the temperature inside the furnace body from the ambient temperature. The structure of the furnace body 1 is not basically different from the structure of a known furnace body such as a heating furnace or a melting furnace. The furnace body 1 is attached to an elevating device that moves up and down. On the bottom surface of the furnace body 1, the roller 13 is mounted on a rail 14 provided with a support member 12 on which a molding die 10 is placed by the vertical movement of the furnace body 1.
It has an opening 1c into which the support frame 15 that moves in the direction can be inserted. Further, the support frame body 15 is provided with a closing member 11 for closing the opening thereof. The closing member 11 shuts off the outside air, and a closing member outer wall 11a having an elevating device for vertically moving the closing member 11 shuts off the outside air. The closed member inner wall 11b is made of a heat insulating material made of a material having a high heat resistance and a high fire resistance. Further, the support member 12 has a mechanism capable of rotating the molding die 10, so that the heating state can be made uniform by rotating the molding die 10.

In addition, the support frame 1 that moves on the rails 14 by the rollers 13
The rails 5 are laid so that the rails 14 can be moved between the respective steps, and can be performed only by moving the rails 14 from the pre-process to the post-process.

Further, two circulation fans 2 and 3 for circulating the hot air inside the furnace body 1 are arranged above the furnace body 1. The circulation fan 2 is composed of an electric motor 2a installed outside the furnace main body 1 and a blade 2b installed inside the furnace main body 1, driven by the electric motor 2a, and arranged inside the hood 8. Similarly,
The circulation fan 3 is an electric motor 3a installed outside the furnace body 1.
And a blade 3b which is driven by the electric motor 3a and is disposed in the hood 8. A support frame body 15 provided with a support member 12 on which the molding die 10 is placed is inserted into the upper part of the furnace body 1, and the support frame body 1 is further provided.
There are provided exhaust ports 4 and 5 for exhausting the exhaust gas and exhausting other exhaust gas when the closing member 11 for closing the opening of 5 is inserted.

Far-infrared ray generators 6 (6A to 6F) and 7 (7A to 7F (not shown)) are arranged on both side surfaces of the furnace body 1 in groups of a plurality of control units. Far-infrared generator 6
As shown in the explanatory view of FIG. 3, the basic configuration of the one used in this embodiment is as follows: a heating port 6a for arranging a heating source such as a flame of the gas burner 6d; and an end of the heating port 6a. Dispersion member 6 that is arranged to disperse the flame of gas burner 6d.
b, the radiating surface 6 formed on the surface of the refractory material 6e such that the dispersion member 6a has a substantially focal point and its cross section draws a parabola.
It is composed of c.

This far infrared ray generator 6 has a gas burner 6d at the heating port 6a.
A heating source such as a flame is disposed, the flame is dispersed by the dispersion member 6b to heat the surface of the radiation surface 6c, and far infrared rays generated from the radiation surface 6c are radiated with a predetermined irradiation width.

Further, the gas burners 6d (6Ad to 6Fd) of the far infrared ray generator 6 (6A to 6F) are piped as shown in FIG. Although not described here, the gas burner 7d (7Ad to 7F, not shown) of the far infrared ray generator 7 is not shown.
d) is similarly configured.

Each gas burner 6Ad of the far infrared ray generators 6A to 6F
6Fd is provided with manual valves V1 to V6 corresponding to the gas burners 6Ad to 6Fd. And the manual valve V
A group switching valve V7 is provided between the anti-gas burner 6Ad side of 1 and the anti-gas burner 6Bd side of the manual valve V2, and a group switching valve V7 of the manual valve V2 is provided between the anti-gas burner 6Cd side and the anti-gas burner 6Cd side of the manual valve V3. A switching valve V9 is provided. Also, the anti-gas burner 6F of the manual valve V6
A group switching valve V8 is provided between the manual valve V5 and the anti-gas burner 6Ed side of the manual valve V5, and a group switching valve V10 is provided between the manual valve V5 and the anti-gas burner 6Dd side of the manual valve V4. It is arranged. The anti-gas burner 6Cd side of the manual valve V3 is directly connected to the anti-gas burner 6Dd side of the manual valve V4 by a conduit. The manual valve V1 is connected to a supply gas adjusting valve V21 which is electrically controlled to be high, low or continuously variable, and the manual valve V6 is connected to a supply gas adjusting valve V23 which is electrically controlled. Further, a supply gas adjusting valve V22 that is electrically controlled is connected to the manual valve V3 and the manual valve V4.

The manual valves V1 to V6 are used for the far infrared ray generator 6
The group switching valves V7 to V10 are used for selecting A to 6F, and the far infrared ray generators 6A to 6 used.
This is used for selecting the group unit of F. For example, when the group switching valve V7 is closed, the group switching valve V9 is opened, the group switching valve V8 is opened, and the group switching valve V10 is closed, the far infrared ray generator 6A can be controlled by the supply gas adjusting valve V21. , Far infrared ray generator 6B, far infrared ray generator 6C and far infrared ray generator 6D are supply gas adjusting valves V
23, and the far-infrared ray generator 6E and the far-infrared ray generator 6F can be controlled by the supply gas adjusting valve V23.

Therefore, in the far infrared ray generators 6A to 6F, the temperature of the molding die 10 is detected by the temperature sensors S1 to S6 (the description is omitted, but the far infrared ray generators 7A to 7F are detected by the temperature sensors S7 to S12. The supply gas adjusting valve V depending on the group determined by the group switching valves V7 to V10.
The combustion is electrically controlled at 21 to V23. In addition, the manual valves V1 to V6 are, depending on the form of the molding die 10 for heating,
The opening and closing is decided.

The heating furnace for the molding die of the present embodiment configured as described above is used as follows.

An elevating device (not shown) that moves the furnace body 1 up and down raises the furnace body 1 to a predetermined position, and an elevating device that moves the closing member 11 up and down lowers the closing member 11 to a predetermined position. Support member 12 on which the mold 10 is placed
By a roller 13 provided on a supporting frame body 15 on which is vertically provided, the rail 14 is moved to a position right below the opening portion 1c of the furnace body 1, and the supporting member 12 and the supporting frame body on which the molding die 10 is placed. The furnace body 1 is put on 15. And the closing member 11
Is raised to close the opening of the support frame body 15,
The opening 1c of the furnace body 1 is closed.

The temperature of the molding die 10 is detected by the temperature sensors S1 to S6 (and S7 to S12) in the state of the manual valves V1 to V6 whose opening and closing are determined by the form of the molding die 10 and the like.
The combustion is electrically controlled by the supply gas regulating valves V21 to V23 by the group determined by the group switching valves V7 to V10. Then, the material itself of the molding die 10 can be heated from the inside by the far infrared rays emitted from the far infrared ray generators 6A to 6F. Further, by rotating the circulation fans 2 and 3, the temperature distribution in the furnace body 1 is made uniform, and the molding die 10 is heated from the outer surface. During this time, the molding die 10 is rotated to make the temperature distribution uniform. When a predetermined time has passed, or by the temperature sensors S1 to S6, the molding die 1
When it is confirmed that the temperature of 0 is equal to or higher than a predetermined temperature, the furnace main body 1 is raised and closed by the lifting device 11
And the rollers 13 provided on the support frame 15 move the rails 14 to move the molding die 10 mounted on the support member 12 to the skin forming step of the next step.

In the skin forming step, the heated molding die 10 and the reservoir tank are integrated, a synthetic resin powder for forming a skin layer is supplied therein, and the molding die 10 and the reservoir tank are repeatedly inverted in that state. Then, a thin film layer is formed by melting the synthetic resin powder. Next, the molding die 10 on which the skin layer is formed is sent to the foam layer molding step. The molding die 10 on which the foam layer is formed is sent to the mold cooling step,
Here, cooling water is applied to the molding die 10 to cool it, thereby cooling the die. In this way, the molded product is released from the molding die 10 cooled to a predetermined temperature or lower. After the mold is removed, the molding die 10 is repeatedly put into the furnace body, reheated, and the above steps are repeated.

In this way, the heating furnace for the molding die of the above-described embodiment is divided into a furnace body 1 for accommodating the molding die 10 placed on the support member 12 and a group of a plurality of control units. Far-infrared generators 6 and 7 arranged in the furnace body 1, and the furnace body 1
It is composed of circulation fans 2 and 3 for circulating the internal air.

Therefore, since the far-infrared ray generator 6 and the far-infrared ray generator 7 are arranged in the furnace body 1 divided into a plurality of control units, the molding die 10 which is a member to be heated by far-infrared ray radiation. Is heated from the inner surface side thereof, and the far-infrared ray generator 6 and the far-infrared ray generator 7 are divided into groups of a plurality of control units and controlled, so that the thickness of the molding die 10 and the like are taken into consideration. Since the radiant energy can be determined, the molding die 10
The temperature distribution can be made uniform.

Further, since the circulation fans 2 and 3 for circulating the air in the furnace body 1 are provided, it is possible to perform heating with warm air in the furnace body 1. Therefore, far-infrared generator 6,7
Since the radiant energy from and the hot air can be heated at the same time, the time required for the molding die 10 to reach a desired temperature can be shortened.

Then, the temperature distribution of the molding die 10 is made uniform, so that the occurrence of thermal strain of the molding die 10 can be prevented, and as a result,
The molding die 10 can have a long life.

By the way, the furnace main body that accommodates the molding die in the state of being placed on the supporting member of the above-mentioned embodiment accommodates the molding die in the state of being placed on the supporting member in the furnace body as in the above-mentioned embodiment. In addition, it is preferable that the molding die can be rotated while being placed on the support member in the furnace body. However, when the present invention is carried out, the mold may not be rotatable.

Further, the far-infrared ray generator arranged in the furnace body divided into a plurality of groups of control units of the above-mentioned embodiment is set to be divided into three groups. The far-infrared ray generator divided into groups of control units may be divided into two or more parts so as to correspond to the form of the molding die.

Further, although two circulation fans for circulating the air in the furnace body of the above embodiment are used, the number of the circulation fans is not limited when the present invention is carried out.

[Effects of the Invention] As described above, in the heating furnace for the molding die of the present invention, the furnace body is divided into a group of a plurality of control units, and the far infrared ray generator and the circulation for circulating the air in the furnace body. A fan is provided and the molding die is accommodated in the furnace body while being placed on the support member.

Therefore, since the far-infrared ray generator is arranged by dividing the furnace body into a group of a plurality of control units, the molding die which is the member to be heated is heated from the inner surface side by radiation of far-infrared ray, and By dividing and controlling the far-infrared ray generator into a group of a plurality of control units, the radiant energy can be determined in consideration of the wall thickness of the molding die, so that the temperature distribution of the molding die can be made uniform. Further, the temperature distribution of the molding die is made uniform, so that the distortion of the molding die can be prevented and the life of the molding die can be extended. Since a circulation fan that circulates the air in the furnace body is provided, it is possible to perform heating by the warm air in the furnace body in parallel, and the temperature can be obtained only by the temperature gradient due to the surface temperature of the molding die. Since the radiant energy from the far-infrared ray generator and the warm air heating can be performed at the same time without raising the temperature, the time required for the molding die to reach a desired temperature can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molding die heating furnace of one embodiment of the present invention seen from the front, and FIG. 2 is a side view of the molding die heating furnace of one embodiment of the present invention shown in FIG. Sectional view seen from the third
FIG. 4 is an explanatory view showing a cross section of a far infrared ray generator used in this embodiment, and FIG. 4 is an explanatory view showing a circuit of a gas supply pipe used in this embodiment. In the figure, 1 is a furnace main body, 2 is a circulation fan, 6 is a far infrared ray generator, 10 is a molding die, and 12 is a support member. In the drawings, the same reference numerals and symbols indicate the same or corresponding parts.

Claims (3)

[Scope of utility model registration request] 1. A furnace main body for accommodating a molding die placed on a support member, a far-infrared generator divided into a plurality of control units and arranged in the furnace main body, and the furnace. A heating furnace for a molding die, comprising: a circulation fan that circulates air in the main body. 2. The molding die according to claim 1, wherein the support member on which the molding die is mounted is rotatable by mounting the molding die thereon. Heating furnace. 3. A far-infrared generator disposed in the furnace body is configured to generate far-infrared rays by heating a radiant surface with a gas burner. A heating furnace for a molding die according to item.