JPS613725A - Molding method of resin material and device thereof - Google Patents

Abstract

PURPOSE:To improve accuracy of a product by making moldability favorable, by a method wherein a thermoplastic resin sheet material whose fringe has been fixed is pressed and molded by a molding die and contact bonding molding is made to perform further to the molding die by a pressed and molten metal after the thermoplastic resin sheet material has been heated and softened by the molten metal. CONSTITUTION:The fringe of a preheated resin sheet material 1 is fixed to a fixing face 5 of a molding tank 2 by a fixing component. Then the above article is heated and softened by a molten metal 3 stuck to the underground of the resin sheet material 1 and pressed and molded by a molding die 12. In this instance, volume sunk into the molten metal 3 is absorbed by a pressing cylinder 13. Main ingredients of the molten metal 3 are bismuth and tin and the fusion point of the same is the temperature of about 124 deg.C. Then contact bonding molding is performed by making the molten metal 3 bond to a molding die 9 with pressure from the lower part by pressing with a pressure piston 15 which is interlocked with a hydraulic cylinder 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for molding thermoplastic resin materials.

(Prior art) Conventional methods for molding thermoplastic resin materials include, for example,
The one shown in FIG. 8 is known.

This conventional method of molding thermoplastic resin material is based on a heater 50.
a heating softening step of heating and softening the resin sheet material 51; a contacting step of bringing the peripheral edge 52 of the resin sheet material 51 softened by the heating softening step into close contact with the upper end peripheral edge 54 of the mold 53; and the contacting step. It is equipped with a vacuum forming process in which the resin sheet material 51 is closely molded to the mold 53 by sucking out the air existing between the resin sheet material 51 and the mold 53 whose peripheral edges are closely contacted by a vacuum pump 55. there were.

(Problems to be Solved by the Invention) However, in such a conventional method of molding a thermoplastic resin material, the resin sheet material 51 is
Since the heating is performed using air with low thermal conductivity as a medium, there is a large energy loss.Furthermore, if there is air flow due to wind or the like, temperature unevenness will occur, and the degree of softening of the resin sheet material 51 will vary depending on the location. Therefore, there was a problem in that it had a negative effect on product accuracy.

Furthermore, during the process transition from the heating process to the adhesion process, the resin sheet material 51 was separated from the heater 50 and began to cool and harden, which also deteriorated moldability and had a negative impact on product precision. .

(Means for solving the problem) Therefore, in order to solve the problem such as "double series", in the first invention, a thermoplastic resin sheet material whose peripheral edge is fixed is heated and softened by molten metal. Thereafter, the method includes a press molding step in which the resin sheet material is compressed by a mold, and a press molding step in which the resin sheet material roughly molded by the press molding step is compressed against the mold using pressurized molten metal,
Further, in the second invention, there is provided a molding tank which contains a molten metal for heating and softening a thermoplastic resin sheet material and is provided with a heater, and the resin sheet material is clamped and fixed to the periphery of the upper end of the molding tank. a fixing member that is movable up and down with respect to the resin sheet material, and a volume absorption tank that is provided in the molding tank and absorbs a change in volume of molten metal due to press molding by the mold. , and a pressurizing means for converting molten metal in the forming tank into pressurized metal.

(Example) 1 is a resin sheet material, which is a sheet made of thermoplastic resin.

2 is a molding tank in which the resin sheet material 1 is heated and softened and then molded; the interior is filled with molten metal 3; a heater 4 is provided; A fixed surface 5 is formed.

The main components of the molten metal 3 are bismuth and tin, and the melting point is about 1246.

Reference numeral 6 denotes a fixing member, which clamps and fixes the resin sheet material 1 with the fixing surface of the fixing tank 2. The fixing member moving piston 8 is located at the upper part of the molding tank 2 and is provided by a support 7. It can be moved up and down by

9 is a mold, which is located above the molding tank 2;
It is provided to be movable up and down by a rod 11 driven by a mold drive device IO.

The mold 9 is provided with a locking groove 12 as a means for preventing the molded product from falling off (FIG. 6).

A pressure cylinder 13 serves as a volume absorption tank, and is communicated with the forming tank 2 through a communication passage 14.

Reference numeral 15 denotes a pressurizing piston as a pressurizing means, which is provided in the pressurizing cylinder 13 and connected to a hydraulic piston 17 of a hydraulic cylinder 16 also serving as a pressurizing means by an interlocking rod 18. Its sliding movement is controlled by a hydraulic cylinder 16.

19 is an oil pump, 20 is a switching valve, 21 is a one-way valve, 2
2 is a pressure relief circuit, and 23 is a release valve.

The release valve 23 is for maintaining the pressurizing force by the pressurizing piston 15 at a set pressure, and when the pressure in the pressurizing side cylinder chamber 161 of the hydraulic cylinder 16 becomes higher than the set value, the release valve 23 23 to remove oil a and lower the pressure.

Further, the switching valve 20 is used to start compression molding and adjust the liquid level of the molten metal 3.

Reference numeral 24 denotes a communication passage heater, which heats the molten metal 3 within the communication passage 14.

25 is a preheating tank which heats the resin sheet material l before sending it to the molding tank to shorten the heating time in the molding tank, and is adjacent to the molding tank 2 and is filled with molten metal 3. A heater 26 and a transfer device 27 are provided.

The transfer device 27 uses a material feed lever 28 to transfer the resin sheet material 1 from a material placement location 29 to the molding tank 2.

A material holding frame 30 holds the resin sheet materials in a stacked state.

31 is a cooling water nozzle that injects cooling water to cool the molded product 1a.

32 is a molded product guide, and 33 is a molded product holder.

Next, the molding method will be explained.

The first step is a preheating step.

The preheating step is a step of preheating the resin sheet material 1 before molding, in which the resin sheet phase 1 is placed on the preheating tank 25 and the entire resin sheet material 1 is heated by the heated molten metal 3 in the preheating tank 25. It heats evenly.

The next step is the compression molding step.

The compression molding step is a step in which the heat-softened resin sheet material 1 is press-molded by the mold 9, and the resin sheet material 1 preheated in the preheating tank 25 is pressed into the resin sheet material 1.
After arranging the resin sheet material 1 so that its peripheral edge is in contact with the fixing surface 5 at the upper end of the molding tank 2, the resin sheet material 1 is clamped and fixed between the fixing member 6 and the fixing surface 5, and the lower surface of the resin sheet material 1 is heated and softened with molten metal 3 in close contact with (Fig. 2),
Thereafter, it is pressed from above using a mold 12 to perform press molding.

At this time, the volume movement of the molten metal 3 corresponding to the volume of the resin sheet material 1 submerged in the molten metal 3 is absorbed by the pressure cylinder 13 serving as a volume absorption tank (FIG. 3).

The next step is the compression molding step.

The pressure-molding step is a step in which the resin sheet material l roughly formed in the pressure-molding step is pressure-molded against the mold 9 using a pressurized molten metal 3, and the resin sheet material 1 is pressed by the mold 9 from both sides. A roughly molded resin sheet material 1 is pressed against a mold 9 from below by a pressurized molten metal 3 pressurized by a pressurizing piston 15 linked to the hydraulic cylinder 16 to perform crimping molding. (Figure 4).

The next step is the removal step.

The removal process is a process of removing the molded product 1a from the mold 9, and when the crimping process is completed, the pressing force of the pressure piston 15 is removed, and the fixed member 6 is moved by the movement of the fixed member moving piston 8. The molded product 1a, which is then molded by the pressure bonding process, is formed in the mold 9 by the +1-. By being locked in the groove 12,
The mold 9 is raised together with the mold 9 by the driving of the mold drive device IO, and taken out from the molding tank 2.

The molded product 1a taken out from the molding tank 2 is cooled by cooling water sprayed from the cooling water nozzle 31 (fifth
), then the mold 9 is removed and the molded product guide 3 is removed.
2 to the molded product holder 33.

Next, a second embodiment shown in FIG. 7 will be described.

This embodiment is an example in which a negative pressure hole 91 using negative pressure is used as a drop-off prevention means.

Therefore, the molded product la formed by the compression molding process is
Negative pressure hole 91 connected to a vacuum pump (not shown)
By creating a negative pressure inside, it is possible to prevent the mold from falling out of the mold 9.

Moreover, when removing the molded product 1a, it can be removed by sending air into the negative pressure hole 91.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, although a preheating process is provided before the compression molding process, although the preheating process is effective in continuously producing the molded product 1a, it is not necessary to provide it, and the preheating process is limited to the preheating tank 25. This may be done by other methods such as using hot water.

Further, the volume absorption tank and the pressurizing means may be provided separately, and the pressurizing means is not limited to the pressurizing piston 15, but air or the like may be used.

In addition, the main components of molten metal 3 are bismuth and tin, and the melting point is 1.
Although a temperature of about 24°C was used, the melting point temperature is not limited to this and may also be determined depending on the resin material.

Further, although the pressurizing means is driven by the hydraulic cylinder 16, it may also be a means such as a spring.

Further, the release valve 23 is effective because it can maintain the pressure applied by the molten metal 3 at a constant set value during compression molding, but it is not necessarily necessary.

Further, the cooling water nozzle 31 may not be provided.

(Effects of the Invention) As described above, according to the present invention, since the resin sheet material is heated using molten metal as a medium, the resin sheet material has high thermal conductivity and little energy loss, and also has low temperature unevenness. The entire material is heated uniformly, resulting in high product precision.

Furthermore, since the resin sheet material is brought into contact with molten metal during molding, the resin sheet material does not harden, resulting in smooth molding and high product precision.

In addition to the above-mentioned effects, in the first embodiment, since a preheating step is provided, the heating time in the molding tank 2 is short and the resin sheet material 1 can be softened. Since a transfer device 27 is provided from the preheating tank 25 to the molding tank 2, continuous production of molded products 1a can be carried out smoothly.

In addition, the release valve 23 allows the pressurizing force of the pressurizing piston 15 by the hydraulic cylinder 16 to be maintained at a constant value, so even if the size and shape of the mold 9 changes, a constant pressurizing force can be obtained, and the pressure is always good. The molding is carried out.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing a resin material molding apparatus according to the first embodiment of the present invention, FIGS. 2 to 5 are cross-sectional views showing the method and apparatus according to the first embodiment of the present invention, and FIG. FIG. 7 is a sectional view showing the main parts of the apparatus according to the first embodiment of the present invention, FIG. 7 is a sectional view showing the main parts of the resin material molding apparatus according to the second embodiment of the invention, and FIG. 8 is a sectional view showing the conventional apparatus. be. l... Resin sheet material 2... Molding tank 3... Molten metal 6... Fixing member 9... Molding mold 13... Pressure cylinder (volume absorption means) 15... Pressure piston (Pressurizing means) Fig. 2 +5 10
15 Figure 5 15 Old Figure 8 procedural amendment (voluntary) March 1985! 5th 1. Indication of the case Patent Application No. 125595 filed in 1982. 2. Title of the invention: Method and apparatus for molding resin materials. Agent Address: 1-5 Shimomeguro, Meguro-ku, Tokyo +9-80
No. 7 (1) Claims column of the specification (2) Detailed explanation of the invention column 6 of the specification, contents of amendment (2) The Detailed explanation of the invention column of the specification has been amended as follows: do. l) On page 3, lines 6 and 7 of the specification, the statement ``The degree of softening will vary depending on the location, resulting in poor product accuracy'' will be corrected as follows. ``The degree of softening will differ partially, resulting in poor formability and poor product accuracy.'' 2) On page 3, line 16 of the specification, the phrase ``after heating and softening with molten metal'' has been changed to 1 molten metal. After softening due to close contact, it is corrected as j. 3) On page 4, line 8 to line 9 of the specification, the phrase ``made into a pressurized metal'' is corrected to read ``make it pressurized by 1''. 4) On page 4, line 19 of the specification, [Melting point is approximately 124°]. ” is corrected to “The melting point is about 124°C. In the first line of page 5 of the specification, it says "Tode...".
5 and...'' I corrected him. 7) The text “Support 7” on page 5, line 2 of the specification indicates T-post 7. ! and correct it. 8) In the second and third lines of page 7 of the specification, the statement ``31 is a cooling water nozzle, which injects cooling water to cool the molded product 1a.'' is replaced with the following: to correct. 1'31 is a cooling nozzle that blows cold air.
. This is for cooling the shape 1a. j 9) The phrase "molded product guide" on page 7, line 4 of the specification is corrected to "molded product holder guide direction." 10) "The above-mentioned press molding process" is written on page 7, line 14 of the specification.
+1) On page 8, line 9 of the specification, the phrase ``the pressure molding process'' is corrected to ``the pressure molding process.'' 12) On page 8, line 10 of the specification, the phrase "pressurized molten metal 3" is corrected to "pressurized molten metal 3." 13) On page 8, line 14 to line 15 of the specification, it says "Pressurized molten metal 3" 1 Pressurized molten metal 3
” he corrected. 14) “Said removal step” on page 8, line 18 of the specification
15) In the 19th line of page 8 of the specification, the phrase ``the crimping process is completed'' is corrected to ``j'' in which the crimping process is completed. 1B) In the second line of page 9 of the specification, "the crimping process" is corrected to ``the crimping process 1. 17) In the 6th to 8th lines of page 9 of the specification. [2 The molded product 1a taken out from the molding tank 2 is taken out from the molding tank 2 by the cooling water injected from the cooling water nozzle 31." is corrected as follows. It is taken out from r2. When the mold rises and stops, the molded product holder 33 guided by the molded product holder guide 32 is set below the mold 9. Next, the molded product 1a taken out from the molding tank 2 is cooled by the cold air blown from the cooling nozzle 31.
The molded product is guided to the molded product holder 33 by the molded product holder 33. '' should be corrected as follows. The molded product is removed from the molded product holder 33 together with the molded product holder guide 32. 15, air, etc. may be used.'' is corrected as follows. ``Either hydraulic pressure, pneumatic pressure, etc. may be used for the piston 15.L 20) In the specification, page 10, lines 18 to 19 [Also, the pressurizing means may be the means of...''. ” will be deleted. 21) In the 4th line of page 11 of the specification, the phrase "cooling water nozzle" is corrected to "A cooling nozzle town." 22) On page 11, line 7 of the specification, the phrase “In order to perform as a medium” has been replaced with “In order to perform in close contact as a medium, j
and correct it. 23) In the 10th line of page 11 of the specification, the phrase "Heated makes the product more accurate." is amended to read "Heated makes the moldability better and makes the product more accurate." 2. Patent Claims l) Melting thermoplastic resin sheet material with fixed peripheral edges
A compression molding process in which the resin sheet material roughly formed in the press molding process is pressed against the mold using pressurized molten metal. 1. A method for molding a resin material, comprising the following steps. 2) a molding tank that accommodates molten metal for heating and softening a thermoplastic resin sheet material and is provided with a heater; a fixing member that clamps and fixes the resin sheet material to the periphery of the end portion of the molding tank; a mold that is movable up and down relative to the resin sheet material; a volume absorption tank that is provided in the molding tank and absorbs changes in volume of molten metal due to press molding by the mold; and molten metal in the molding tank. 1 roll) (with pressurizing means,
A resin material molding device characterized by comprising:

Claims (1)

[Scope of Claims] 1) A press molding process in which a thermoplastic resin sheet material with a fixed peripheral edge is heated and softened with molten metal and then press-molded using a mold, and a resin roughly molded by the press-molding process. A method for molding a resin material, comprising a pressure molding step of molding a sheet material against a mold using pressurized molten metal. 2) a molding tank that contains a molten metal for heating and softening a thermoplastic resin sheet material and is provided with a heater; a fixing member that clamps and fixes the resin sheet material to the periphery of the upper end of the molding tank; A molding die provided to be movable up and down relative to the sheet material; a volume absorption tank provided in the forming tank to absorb changes in volume of molten metal due to press forming by the forming die; A molding apparatus for a resin material, comprising: a pressurizing means for pressurizing metal.