JPH053374B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for molding a synthetic resin material and an apparatus for molding the same.

[Prior art]

Conventionally, among the molding methods for obtaining molded products made of thermosetting synthetic resin materials reinforced with reinforcing materials such as glass fibers, one of the molding methods with low molding pressure is to open the upper and lower molds. After opening the molding space and setting a reinforcing material such as glass fiber in the molding space, the upper and lower molds are closed and the closed molding space is filled with a thermosetting synthetic resin material. A resin inject molding method is used in which the resin is cured.

This resin inject molding method has the advantage of low equipment costs, but the molding time is long.
It has the disadvantage of low productivity. The reasons for this are: (1) Since the molding pressure is low, wood, resin, gypsum, etc. are used as mold materials, and these materials have poor thermal conductivity.

(2) It is well known that the curing reaction of thermosetting synthetic resin materials is accelerated by heating, but even if a heating device is installed inside the mold, the effect of curing acceleration is limited due to the poor thermal conductivity of the mold. is not enough.

(3) As a result of (1) and (2) above, the molding time becomes longer.

Therefore, when considering a method to shorten the molding time while taking advantage of the advantages of the resin injection molding method, the following conditions are required.

(1) When workers set reinforcing materials such as glass fibers in the molding space of the mold or take out the molded product from the mold, there is a high possibility that the worker will touch the mold, so for safety reasons, It is desirable that the temperature of the mold at this time be low.

(2) The temperature of the mold must be high from the time the reinforcing material such as glass fiber is set until the synthetic resin material hardens.

(3) In order to further shorten one molding cycle, it is necessary to shorten the switching from low temperature to high temperature and from high temperature to low temperature in (1) and (2) above.

A conventional technique corresponding to condition (3) above is known as Japanese Patent Laid-Open No. 51-5362, and will be explained with reference to the schematic diagram of FIG.

In FIG. 3, 51 is a lower mold, and the upper surface of this lower mold 51 is formed with a molding surface 51a that opens upward. Further, an upper mold 52 is disposed above the lower mold 51, and a molding surface 52a that opens downward is formed on the lower surface of the upper mold 52. When the lower mold 51 and the upper mold 52 are closed together, a molding space is formed between the molds 51 and 52.

Moreover, the molding surfaces 51a, 5 of the lower mold 51 and the upper mold 52
Passages 51b and 52b for alternately supplying a heating medium and a cooling medium are formed adjacent to 2a. 2nd switching valve 5
7 is connected.

Further, a heating device 58 is provided near the first switching valve 55.
A cooling device 59 is provided, and a heating device 58 is provided.
is connected to the first switching valve 55 by a pipe 60a, and connected to the second switching valve 57 by a pipe 60b. In addition, the cooling device 59 has a pipe 61a.
is connected to the first switching valve 55 by a pipe 61.
b to the second switching valve 57.

When molding a molded product using a thermosetting synthetic resin material, a cooling medium is passed from the cooling device 59 through the passage 51b of the lower mold 51 and the passage 52b of the upper mold 52 to form the molding space 53. Surfaces 51a, 52
After lowering b to an appropriate temperature, a reinforcing material such as glass fiber is set on the open molding surface. Next, the first switching valve 55 and the second switching valve 57 are switched to allow the heating medium from the heating device 58 to pass through the passage 51b of the lower mold 51 and the passage 52b of the upper mold 52, thereby forming the molding space 53.
While heating the molding surfaces 51a and 52b to an appropriate temperature, the lower mold 51 and the upper mold 52 are closed together. Thereafter, a synthetic resin material for molding is filled into the molding space 53 and cured by heating.

However, in such a resin injection molding method, the molding surface 5 of the molding space 53
Although it is easy to switch 1a and 52b from high temperature to low temperature or from low temperature to high temperature, there are the following problems.

That is, by using the same heating medium and cooling medium fluid in the heating device 58 and the cooling device 59,
Since the heating medium and the cooling medium are alternately passed through the passages 51b and 52b of the molding molds 51 and 52, it takes a long time to replace the heating medium and the cooling medium into the passages 51b and 52b, and the molding space 53 is Molding surface 5
It takes a long time for the temperatures of 1a and 52a to reach the desired temperature.

Further, as shown in FIG. 3, from a state in which the cooling medium cooled by the cooling device 59 is circulated through the passages 51b and 52b, the heating medium heated by the heating device is circulated through the passages 51b and 52b. 52b, the first switching valve 55 and the second switching valve 57
When switching the first switching valve 55 to the passage 51
Since the cooling medium remaining in the piping passageway up to the second switching valve 57 via b and 52b flows into the heating device 58, the temperature of the heated heating medium temporarily drops. Conversely, when switching from the heating state to the cooling state, the heating medium remaining in the piping passage flows into the cooling device 59, and the temperature of the cooled cooling medium temporarily increases. As a result, the molding space 53
Temperature switching on the molding surfaces 51a and 52a becomes slow, and the molding cycle becomes longer.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a heating medium supply passage and a cooling medium supply passage close to the molding space formed by the upper mold and the lower mold. is formed independently along the molding space, thereby shortening the time required for the temperature of the molding surface of the molding space formed by the upper mold and the lower mold to reach the desired temperature, It is an object of the present invention to provide a method for molding a synthetic resin material and a molding apparatus therefor, which can shorten the molding cycle.

[Structure of the Invention] In order to achieve the above object, the structure of the method for molding a synthetic resin material according to the present invention is such that a heating medium is placed in the vicinity of the molding space formed by the upper mold and the lower mold. Using a mold in which a supply passage and a cooling medium supply passage are formed independently in the molding space, the cooling medium is passed through the cooling medium supply passage to lower the molding surface of the molding space to an appropriate temperature, and then A fiber reinforcing material is set on the open molding surface, compressed gas is passed through the cooling medium supply passage to discharge the cooling medium from the cooling medium supply passage, and a heating medium is supplied to the heating medium supply passage. The molding surface of the molding space is heated to an appropriate temperature, and then the upper and lower molds are closed together, and the molding space is filled with a synthetic resin material for molding and cured by heating. be.

Furthermore, the configuration of the apparatus for molding a synthetic resin material according to the present invention is such that each of the upper mold and the lower mold has a heating medium supply passageway adjacent to the molding space formed by the upper mold and the lower mold. and a cooling medium supply passage are formed independently, and a means for heating and supplying a heating medium fluid and a means for pumping gas are provided in the heating medium supply passage so as to be switchable with each other, and Means for cooling and supplying refrigerant fluid to the passage and means for pumping gas are provided so as to be switchable with each other.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic plan view of a synthetic resin material molding apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line - in FIG. 1.

In FIGS. 1 and 2, 1 is a lower mold made of gypsum, the upper surface and both side surfaces of this lower mold 1 are covered with a metal material, and the upper surface is open upward. Concave molding surface 1
a is formed, and its periphery forms a flat contact surface 1b. Further, an upper mold 2 is disposed above the lower mold 1, and its lower surface and both side surfaces are covered with a metal material similarly to the lower mold 1. This upper mold 2 has a concave molding surface 2a formed at a portion facing the molding surface 1a of the lower mold 1,
A flat abutment surface 2b is formed around it, which abuts against the abutment surface 1b of the lower die. When the lower mold 1 and the upper mold 2 are closed together, a molding space 3 is formed between the molds 1 and 2.

In addition, each of the metal parts of the lower mold 1 and the upper mold 2 has a supply passage 4 through which a heating medium passes in proximity to a molding space 3 formed by the lower mold 1 and the upper mold 2, and a cooling medium. Supply passages 5 are formed independently for each passage.

Further, a first switching valve 6 is provided near the molds 1 and 2.
Second switching valve 7, third switching valve 8 and fourth switching valve 9
is installed. Of these, the first switching valves 6 each communicate with the inlet side of the supply passage 4 through a pipe 10a, and the second switching valves 7 each communicate with the outlet side of the supply passage 4 through a pipe 10b. Further, the third switching valves 8 are connected to the inlet side of the supply passage 5 through pipes 10c, and the fourth switching valves 9 are connected to the outlet side of the supply passage 5 through pipes 10d.

Further, a heating device 11 for heating the heat medium fluid and a supply device 12 for supplying high pressure gas such as compressed air are arranged near the first switching valve 6, and the outlet side of the heating device 11 is connected to a pipe 13a. Therefore, the first switching valve 6
The inlet side is connected to the second
It is connected to the switching valve 7. In addition, the supply device 12
The outlet side of is connected to the first switching valve 6 and the third switching valve 8 by a pipe 13c.

Further, a cooling device 14 for cooling the refrigerant fluid is arranged near the third switching valve 8, and its outlet side is connected to the third switching valve 8 by a pipe 15a, and its inlet side is connected to the third switching valve 8 through a pipe 15a. It is connected to the fourth switching valve 9 by a pipe 15b.

In the synthetic resin material molding apparatus configured as described above, when molding a molded product using a thermosetting synthetic resin material, the upper mold 2 is separated from the lower mold 1 to open the molding space 3. , molding surface 1 of lower mold 1
Set reinforcing material such as glass fiber on a. During this time, the third switching valve 8 is switched to allow the cooling medium from the cooling device 14 to flow through the supply passage 5 to cool the molding surface 2a of the upper mold 2 and the molding surface 1a of the lower mold 1, respectively.

After the reinforcing material is set on the molding surface 1a of the lower mold 1, the third switching valve 8 and the fourth switching valve 9
is switched to flow high-pressure gas from the supply device 12 to the supply passage 5, and the cooling medium remaining in the supply passage 5 is discharged. Thereafter, the third switching valve 8 and the fourth switching valve 9 are switched again to maintain the neutral state, and the first switching valve 6 is switched to maintain the heating device 11.
The heating medium from the upper mold 2 is passed through the supply passage 4 and
The molding surface 2a of the lower mold 1 and the molding surface 1a of the lower mold 1 are respectively heated to appropriate temperatures.

Next, the upper mold 2 is closed to the lower mold 1, and a thermosetting synthetic resin material such as unsaturated polyester resin is applied to the molding space 3 filled with reinforcing material, which is closed by both molds 1 and 2. Let it fill. The thermosetting synthetic resin material filled in the molding space 3 heated to an appropriate temperature is accelerated to harden by heating, hardens within a short time, and can be removed from the molds 1 and 2.

Subsequently, the first switching valve 6 and the second switching valve 7 are switched to allow high-pressure gas to flow from the supply device 12 to the supply passage 4, and the heating medium remaining in the supply passage 4 is discharged. Thereafter, the first switching valve 6 and the second switching valve 7 are switched again to maintain the neutral state, and the third switching valve 8 is switched to allow the cooling medium from the cooling device 14 to flow through the supply passage 5, so that the lower mold 1 The molding surface 1a of the upper mold 2 and the molding surface 2a of the upper mold 2 are respectively cooled.

Thereafter, the upper mold 2 is separated from the lower mold 1 to open the molded part, and the molded product is taken out from the lower mold 1 to complete one cycle. Then, the second cycle of molding is performed in the same manner as described above.

Note that the timing of cooling or heating the molds 1 and 2 in the present invention is not limited to this embodiment, and the molds 1 and 2 are cooled when there is a high possibility that an operator will touch the molds 1 and 2. However, if this is not the case, you can also heat it. Furthermore, the molding apparatus of the present invention can also be applied to thermoplastic synthetic resin materials, in which case the molding surfaces 1a and 2a are heated while the thermoplastic synthetic resin material is being poured into the molds 1 and 2. This prevents an increase in viscosity due to a temperature drop in the synthetic resin material, and after injection is completed, the molding surfaces 1a and 2a are cooled to solidify the synthetic resin material.

〔Effect of the invention〕

As explained above, in the synthetic resin material molding method and the molding apparatus according to the present invention, a heating medium supply passage and a cooling medium are provided adjacent to the molding space formed by the upper mold and the lower mold. Since the supply passage is formed independently along the molding space, the time required for the temperature of the molding surface of the molding space formed by the upper mold and the lower mold to reach the desired temperature is shortened. There is an effect that can be done.

Further, in the present invention, since the time required to reach a desired temperature can be shortened, the production amount per unit time can be greatly increased.

Further, in the present invention, since the heating circuit and the cooling circuit are provided independently, the energy capacity for heating and cooling is reduced, and the operating cost is reduced.

Further, in the present invention, since the mold is cooled when there is a high possibility that the worker will touch the mold, it is possible to maintain an appropriate working environment temperature similar to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a synthetic resin material molding apparatus according to the present invention. FIG. 2 is a sectional view taken along the - line in FIG. 1. FIG. 3 is a schematic cross-sectional view of a conventional synthetic resin material molding apparatus. DESCRIPTION OF SYMBOLS 1... Lower mold, 1a... Molding surface, 1b... Contact surface, 2... Upper mold, 2a... Molding surface, 2b... Contact surface, 3... Molding space, 4... Supply passage , 5...
Supply passage, 6...First switching valve, 7...Second switching valve, 8...Third switching valve, 9...Fourth switching valve, 10
a, 10b, 10c, 10d...pipe, 11...
... Heating device, 12 ... Supply device, 13a, 13
b, 13c...Pipe, 14...Cooling device, 15
a, 15b...Pipe.

Claims (1)

[Claims] 1. A molding method in which a heating medium supply passage and a cooling medium supply passage are independently formed in the molding space formed by an upper mold and a lower mold in the vicinity of the molding space. After cooling the molding surface of the molding space to an appropriate temperature by passing the cooling medium through the cooling medium supply passage using a mold, a fiber reinforcement material is set on the open molding surface and compressed into the cooling medium supply passage. Discharging the cooling medium from the cooling medium supply passage by circulating gas,
A heating medium is passed through the heating medium supply passage to heat the molding surface of the molding space to an appropriate temperature, and then the synthetic resin material for molding is placed in the molding space that is closed by closing the upper mold and the lower mold. A method for molding a synthetic resin material, characterized by filling the material with heat and curing it. 2. A heating medium supply passage and a cooling medium supply passage are independently formed in each of the upper mold and the lower mold in proximity to the molding space formed by the upper mold and the lower mold, and A means for heating and supplying the heating medium fluid and a means for pumping the gas are provided in the medium supply passage so as to be switchable with each other, and a means for cooling and supplying the refrigerant fluid and a means for supplying the gas under pressure are provided in the cooling medium supply passage. 1. An apparatus for molding a synthetic resin material, characterized in that means for molding a synthetic resin material are provided so as to be switchable with each other.