JPH06210636A - Method and apparatus for producing resin molded product - Google Patents

Abstract

PURPOSE:To produce a resin molded product excellent transfer ratio by supplying the liquids heated by three high, medium and low temp. controllers to a mold without boiling them to control the mold to high temp. and medium temp. CONSTITUTION:A high temp. sensor 23 is provided to the upper mold 10a of a mold 10 so as to detect the temp. of the upper mold and a temp. sensor 24 is provided to the lower mold 10b thereof so as to detect the temp. of the lower mold 10b and, further, a temp. sensor 25 detecting the temp. of a resin is provided. A control box 22 is connected to respective temp. controllers 11, 12, 13 by wirings 26, 27, 28 and also connected to changeover valves V1, V2, V3, V4, V5, V6, V7, V8 by wiring 29. Therefore, the time required in one cycle of heating, processing, quenching, cooling, demolding and taking-out is set to a short time of about 5min and, further, by holding temp. at the time of processing to constant high temp. of about 150 deg.C, transfer properties can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and a manufacturing apparatus for manufacturing a resin molded product by blow molding or the like.

[0002]

2. Description of the Related Art Generally, car body exterior parts such as spoilers for automobiles can be provided in large quantities at low cost by making them by resin molding such as blow molding. However, these parts are exterior parts. , Surface smoothness and paintability are required. In order to meet this demand, a mold and a temperature control device for manufacturing a mold with good rolling property are required.

FIG. 4 is a schematic view of a conventional molding die temperature control device. (See SAE paper 880359). In FIG. 4, 1 is a high temperature temperature controller, 2 is a low temperature temperature controller, and 3 is a molding die (mold). Mold 3 is thin and liquid (oil)
It is a combination type made of aluminum with many circulation flow paths of
A spoiler is manufactured by supplying a parison to a mold matching space, that is, a cavity, and molding the parison by blow molding. Since a high-temperature liquid is supplied to the molding die 3 from the high-temperature controller 1, the mold surface becomes a temperature close to the melting temperature of the parison resin, and the plasticity of the resin compliments the mold surface, resulting in good rolling property. I have a product. After molding, a low-temperature liquid is supplied from the low-temperature temperature controller 2 to the mold 3, so that the mold temperature is lowered and the molded product is cured (vitrified), so that it can be taken out from the mold without deformation. It is a thing.

FIG. 5 is a schematic view of a conventional molding die constant temperature control device. In FIG. 5, 3 is a mold, 4 is a cooling tower, and 5 is a temperature controller. In this case, when the temperature of the mold 3 is low, the liquid in the cooling tower 4 is adjusted to the temperature controller 5
Is supplied to the mold 3 from the passage 6 through the heated heater of the cooling tower 4, and when the temperature of the mold 3 is high, the liquid in the cooling tower 4 is passed from the passage 6 through the unheated heater of the temperature controller 5 to the mold 3 The temperature of the mold 3 is constantly adjusted to a constant temperature, and thereby the rolling rate is improved.

[0005]

However, all of these conventional ones can improve the die rolling rate on the surface of the molded product, but the molding cycle for manufacturing the molded product takes a long time. There was a problem.

That is, since the former has two temperature controllers, one for high temperature and one for low temperature, it takes time to cool from high temperature to low temperature and to heat from low temperature to high temperature. There is a problem that the cycle takes time, and the latter is
However, there is still a problem in the cycle of manufacturing the product, because only the effective device for adjusting the rolling temperature is disclosed and the thermal cycle of the mold is not disclosed at all.

Therefore, the present invention provides a method and an apparatus for producing a resin molded product, which does not require one cycle of production and can contribute to an improvement in rolling rate.
The purpose is to solve the above problems.

[0008]

In order to achieve the above object, the present invention provides a first step of supplying a hot liquid to a mold to raise the temperature of the mold to a high temperature. The second step of supplying a predetermined amount of resin into the mold cavity, and applying a pressure for molding to the resin inside while maintaining the mold at a high temperature to form a shape along the cavity surface of the mold. A third step of forming, a fourth step of stopping the supply of the high temperature liquid to the forming die and supplying a low temperature liquid until the temperature of the forming die decreases to a substantially medium temperature, and a low temperature of the forming die A fifth step of stopping the supply of the liquid and supplying the medium temperature liquid until the temperature of the resin molded product drops to the middle temperature, and a sixth step of removing the molded product from the molding die, and these steps 1 A molded product is obtained as a cycle. 2. A liquid heated to a temperature exceeding the boiling point as a high-temperature liquid is supplied while maintaining a pressure at which it does not boil, and claim 3 is a mold having a liquid flow path, and the mold has a high temperature. A high temperature temperature controller for supplying the liquid, a medium temperature temperature controller for supplying the medium temperature liquid to the molding die, a low temperature temperature controller for supplying the low temperature liquid to the molding die, the molding die and A pipe that connects each temperature controller substantially independently to form a flow path of the liquid, a valve device that controls the flow direction of the liquid in the pipe, and controls the temperature controller and the valve device. A control box is provided, and the temperature controller for high temperature and the temperature controller for intermediate temperature respectively bypass the molding die and short-circuit the liquid sending pipe and the liquid returning pipe. A bypass pipe and a valve device, and the valve device is provided when the liquid is supplied to the molding die. It is obtained by substantially close as.

[0009]

According to the first, second and third aspects of the present invention, since the mold which is supplied without boiling the liquid heated by using the three high, medium and low temperature controllers is controlled and adjusted to the high temperature and the medium temperature, the heating and the rapid cooling can be performed. This can be done efficiently and the time is shortened, so that the time for one cycle can be shortened. That is, the temperature of the resin mold product becomes medium temperature by the medium temperature controller when the temperature of the molding die becomes almost medium temperature by rapidly cooling the molding die by the high temperature controller and processing and then rapidly cooling it by the low temperature controller. Temperature control up to. As a result, variations in temperature due to rapid cooling in the low temperature controller are adjusted, and
Since the heating and quenching time becomes shorter, the total time of one cycle can be shortened, and therefore the next manufacturing cycle can be immediately started.

Further, according to the present invention, since the high and medium temperature controllers are provided with the bypass, hammering at the start and stop of the flow of the liquid can be prevented and the piping system is not hindered.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the configuration will be described with reference to the block conceptual diagram of FIG. In FIG. 1 (a), 11 is a temperature controller (T for high temperature) having a 50-liter acrylic tank (container).
H), 12 is a temperature controller for medium temperature (TM) having a 20 liter tank (container), 13 is a temperature controller for low temperature (may be a pump) (TL), and these are heater and cooling in the container, respectively. It is equipped with a vessel (heat exchanger), a temperature sensor, and a pump to adjust (control) a liquid (for example, water) to a substantially constant high temperature, medium temperature and low temperature. In addition, high temperature temperature controller (T
H), the pump installed in the medium temperature controller (TM),
The liquid can be supplied while maintaining a pressure higher than a pressure at which the liquid heated to a temperature equal to or higher than the boiling point (under atmospheric pressure) does not boil in a pipe flow path described later. However, the temperature controller for low temperature 13
Here, as the low-temperature liquid, normal temperature (environmental temperature) tap water, ground water, etc., which will be described later, can be used, and since it is not necessary to actively control the temperature, a simple pump without a heat exchanger may be used. is there. Reference numeral 10 is a molding die (mold) for making a spoiler for automobiles from a resin. By combining an upper die (cavity die) 10a and a lower die (core die) 10b, a resin to be used is supplied and a desired molded article is obtained. It has a cavity 10C inside which a spoiler can be obtained (see FIG. 2). Then, heat this in the mold 10,
Alternatively, the upper and lower molds are provided with liquid flow paths (cooling pipes having an internal capacity of 4.5 liters) 33 and 34 for cooling. The flow paths 33, 34 of the mold are connected to the high temperature temperature controller 11 by a liquid sending pipe (pipe) 14 and a liquid returning pipe 15, and the medium temperature temperature controller 12 is connected to a liquid sending pipe 16. The low-temperature pump 13 is connected by a liquid return pipe 17 and is connected to a low-temperature pump 13 by a liquid feed pipe 18 and a liquid return pipe 19.
Connected by. Each tube 14, 15, 16, 17, 1
8 and 19 have switching valves V, V, V,
V, V and V are provided. High temperature controller 1
The bypass pipe 20 that bypasses the molding die and short-circuits the liquid sending pipe 14 and the liquid returning pipe 15 in the temperature controller 1 and the intermediate temperature controller 12.
Further, a bypass pipe 21 that short-circuits the liquid sending pipe 16 and the liquid returning pipe 17 is provided, and the bypass pipes 20 and 21 are provided with switching valves V 1 and V 2, respectively.

As shown in FIG. 2, the molding die 10 is provided with a temperature sensor 23 for detecting the temperature of the upper die (cavity die) 10a for high temperature, and the lower die (core die) 10a.
A temperature sensor 24 for detecting the temperature of the lower mold is provided at b, and a temperature sensor 25 for detecting the temperature of the resin (medium or low temperature) is provided at b, and these are connected by wires 30, 31 and 32 to the control box 22 ( 1 (a)). Control box 22 is for each temperature controller 1
1, 12 and 13 are connected by wirings 26, 27 and 28, and each switching valve V, V, V, V,
The wires 29 are connected to V, V, V and V.

In FIG. 1 (a), the thick line is piping, the thin line is wiring, and the temperature control liquid flow path has a solid arrow for heating, a dotted arrow for rapid cooling (pump 13 operation), and a dashed line for arrow. The one when cooled is shown.

Further, in FIG. 2, as the position of each temperature sensor,
It is best for both mold temperature sensors 23 and 24 to be as close as possible to the cavity surface 10d and not to project into the cavity surface 10d, but in reality there is a processing limitation, and it is more than the cavity surface (mold surface) 10d. It is preferable that the distance is ˜3 mm. Further, the resin sensor 25 preferably projects from the cavity surface 10d to about half the thickness of the parison (resin) 10e. Then, it is preferable that the molded product, here, a portion that does not become the outer surface of the spoiler for automobile, for example, a portion on the back side that becomes a vehicle body mounting portion.

The terms high temperature, medium temperature and low temperature in the present specification do not mean absolutely fixed temperatures but vary depending on the resin used.

The high temperature means a temperature at which the resin used is heated to soften and flow, or particularly preferably does not flow in a natural state, but by applying a pressure of 4 to 5 kg / cm ² or more. Flowable temperature (also referred to as rollable temperature, softening point temperature or heat deformation temperature).

The medium temperature is a temperature lower than the high temperature and higher than the low temperature described below, specifically, a temperature at which the resin molded article is not deformed by its own weight when removed from the mold. Finally, the low temperature is a temperature lower than the medium temperature, that is, the temperature in the working environment, the temperature of the cooling water, or the room temperature, for example, 2
The one at 5 ° C. In FIG. 1A, a cooling tower 35 and a pressure adjusting valve 36 are provided on the liquid return pipe 19 of the low temperature pump 13, and the liquid warmed in the molding die 10 is returned to the low temperature pump 13 as pressure adjusted cooling water. I am trying.

Next, the operation of the above embodiment will be described with reference to FIG. FIG. 3 is a diagram showing a heat cycle application state during blow molding of a resin, a mold temperature during one cycle, and an operating state of each switching valve V-. The resin used here is a polymer alloy of PPE (polyphenylene ether) + PA (polyamide). The resin contains a fiber reinforcing material and a filler as additives.

Each temperature controller for controlling the temperature of the liquid supplied to the molding die 10 is such that the high temperature temperature controller 11 is a liquid (water) having a boiling point (100 ° C.) or higher, that is, In the example, the softening point of 150 ° C. or higher is maintained at a constant temperature of 180 ° C.
The temperature is kept constant at .degree. C. and the low temperature pump 13 is kept at room temperature 25.degree.

The operation sequence of the apparatus of this embodiment is as follows.

(1) As a premise, description will be made by ignoring heat loss.

(2) The cavity mold 10a and the core mold 10b are opened at the end of the previous cycle, and V is open and V
Is closed.

(3) V is opened.

(4) Close V. As described above, the reason for providing the time difference is to prevent the piping system from being hindered by the hammering phenomenon when V is simultaneously closed or opened.

(5) Water (liquid as a medium) flows from the high temperature temperature controller 11 to the pipe 14, V, mold 10, V. By circulating through the pipe 15 to the temperature controller 11, both molds 10a, 1
0b is heated. At this time, it is preferable to keep the pressure of water in the pipe flow path connecting the pipes 14 and 15 and the mold 10 at a pressure of about 10 to 15 kg / cm ² , so that the water is boiled in the pipe flow path. There is nothing to do.

(6) After a lapse of a predetermined time, an accumulator of a blow molding machine (not shown) is started by a command from the control box 22 to lower the parison 10e.

(7) Both molds 10a and 10b are closed. In this case, an unillustrated hydraulic cylinder is operated by a command from the control box 22.

(8) The blow pin (not shown) is the core mold 10b.
The parison 10b is pierced by piercing the hole, and compressed air is blown into the parison 10b.

(9) The parison 10e in the cavity 10c
Expands.

(10) The expanded outer surface of the parison 10e contacts the cavity surface 10d of the molding die 10.

(11) The pressure of the air in the parison 10e is 5 to 7 kg / cm ² , and the parison 10e has a cavity surface 10
It is kept crimped to d.

(12) Since the heat from the die 10 is transferred to the surface of the parison 10e which is in contact with the cavity surface 10d of the die 10, the surface of the parison 10e is kept in a softened state without being rapidly cooled and hardened. In other words, it has softened.

(13) Due to the combination of the above (11) and (12), the outer surface of the parison 10e flows under the above-mentioned pressure, even though the temperature is not such that it sags, and the cavity surface 1
The 0d shape is faithfully transferred to the parison surface. The above items (1) to (13) correspond to the column of heating time A including heating and processing in FIG.

(14) After the completion of the rolling, V
Open.

(15) V is closed.

(16) The low temperature pump 13 is operated.

(17) V is opened.

(18) According to a command from the control box 22, water is supplied from the low temperature pump 13 to the pipe 1 for a predetermined time.
8, V, mold 10, V, pressure regulating valve 36, cooling tower 35, and pipe 19 to circulate to the pump 13 until the temperature (medium temperature) below the softening point of the parison 10e is reached. Both cool rapidly. The above items (14) to (18) correspond to the column for rapid cooling B in FIG.

(19) V is closed.

(20) The pump 13 is stopped.

(21) V is opened.

(22) V is closed.

(23) In response to a command from the control box 22, water is supplied from the medium temperature temperature controller 12 to the pipe 1 for a predetermined time.
6, temperature regulator 12 through valve, mold 10, V, and pipe 17
And the mold temperature is maintained at a medium temperature below the softening point, that is, at a temperature at which it is not deformed by its own weight, and the molded product is held under pressure in the mold. The pressure retention and heat retention time are determined by the characteristic temperature of the resin used and the time required for the mold surface to roll. In this embodiment, it is about 3 minutes as shown in the column of cooling time (during temperature control) C in FIG. 3, but in reality, it is generally determined experimentally. By this temperature adjustment, the variation ΔT of the mold temperature (medium temperature) during quenching is eliminated by the adjustment, and the temperature is maintained at a constant temperature.

(25) The valve of the blow molding machine (not shown) is opened to bring the compressed air in the parison 10e to atmospheric pressure.

(26) The mold 10 is opened to release the molded product, and the product is taken out.

In this embodiment, as shown in FIG. 3, the time required for one cycle of heating, processing, rapid cooling, cooling (heat retention), mold release and take-out is as short as 5 minutes. By maintaining the temperature at a constant high temperature of 150 ° C, good rolling property can be obtained, and by keeping the cooling (temperature control) temperature at a medium temperature of 120 ° C, the molded product can be released and released. It can be taken out easily without deformation, and can also contribute to shortening the heating time in the next cycle.

In the above embodiment, V
Was described as an on-off valve, but when V is connected between V and V and V is connected between V and V (see FIG.
(See (b)) These can be used as other directional control valves, for example. At this time, V, V
, V must be switched at the same time.

Although the bypass pipes 20 and 21 and V are used for the purpose of preventing hammering, they have been described, but they may be replaced with a separate hammering preventing device which does not cause hammering. .

In the embodiment, the resin molded product is obtained by blow molding. However, the present invention is not limited to this, and other molding methods such as injection molding and compression molding can be used. Is also applicable.

[0050]

As described above, according to the present invention, it is possible to obtain the effects that the molding cycle of the resin molded product can be shortened and the resin molded product can be manufactured with a good rolling rate.

[Brief description of drawings]

FIG. 1A is a block conceptual diagram of a manufacturing apparatus showing an embodiment of the present invention. FIG. 1B is a partial view of piping of another example of the main part of FIG.

FIG. 2 is a cross-sectional view of the molding die of FIG. 1 (a).

FIG. 3 is a diagram showing a heat application state, a mold temperature, and an operating state of each switching valve in one cycle of manufacturing the apparatus shown in FIG. 1 (a).

FIG. 4 is a block diagram of a conventional manufacturing apparatus with a high / low temperature regulator.

FIG. 5 is a block diagram of a conventional manufacturing apparatus with a constant temperature controller.

[Explanation of symbols]

 10 Mold (Mold) 10a Upper Mold (Cavity Mold) 10b Lower Mold (Core Mold) 10c Cavity 11 High Temperature Temperature Controller (TH) 12 Medium Temperature Temperature Controller (TM) 13 Low Temperature Temperature Controller (Pump) (TL) 14 Liquid transfer pipe (piping) 15 Liquid return pipe (piping) 20 Bypass pipe 21 Bypass pipe 22 Control box 23 Upper mold temperature sensor 24 Lower mold temperature sensor 25 Resin temperature sensor 26 Wiring 33 In mold Liquid flow path (outward pipe) 34 Liquid flow path in mold (return pipe) 35 Cooling tower 36 Pressure adjusting valve V ~ Switching valve (valve device)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Noriyuki Murobushi, Inventor No. 320 Fujii, Kamiyabe-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hashimoto Forming Industry Co., Ltd. (72) Koji Nozawa, Kamiyabe-cho, Totsuka-ku, Yokohama 320 Fujii Hashimoto Forming Industry Co., Ltd. (72) Inventor Akira Umiuchi 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. A first step of supplying a high temperature liquid to a mold to raise the temperature of the mold, a second step of supplying a predetermined amount of resin into a cavity of the mold, and the mold. The third step of forming a shape along the cavity surface of the mold by applying pressure for molding to the resin inside while keeping the temperature at a high temperature, and stopping the supply of the high temperature liquid to the mold. A fourth step of supplying a low-temperature liquid until the temperature of the molding die decreases to a substantially medium temperature, and a step of supplying a low-temperature liquid to the molding die until the temperature of the resin molded article decreases to a medium temperature. A method for producing a resin molded article, comprising a fifth step of supplying a liquid and a sixth step of removing a molded article from the molding die, and obtaining a molded article by making these steps one cycle. 2. The method for producing a resin molded article according to claim 1, wherein a liquid heated to a temperature higher than a boiling point is supplied as a high-temperature liquid while maintaining a pressure at which it does not boil. 3. A molding die having a liquid flow path, a high temperature temperature controller for supplying a high temperature liquid to the molding die, an intermediate temperature temperature controller for supplying a medium temperature liquid to the molding die, A low-temperature temperature controller that supplies a low-temperature liquid to the molding die, a tube that connects the molding die and each temperature controller substantially independently to form a flow path of the liquid, and a pipe for the liquid in the pipe. An apparatus for manufacturing a resin molded product, comprising a valve device for controlling a flow direction and a control box for controlling each of the temperature regulators and the valve device. 4. The high temperature temperature controller and the medium temperature temperature controller each have a bypass pipe and a valve device for bypassing the molding die and short-circuiting the liquid sending pipe and the liquid returning pipe, The resin molded product manufacturing apparatus according to claim 2, wherein the valve device is substantially closed when the liquid is supplied to the molding die.