JPS6315889B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a raw material supply method for a multi-component liquid plastic raw material mixing device used in a high-pressure reaction molding machine. As is well known, a multi-component liquid plastic raw material mixing device is configured to collide and mix two or more liquid plastic raw materials in a mixing chamber to cause a chemical reaction, and then feed them into a mold. As an apparatus for supplying liquid plastic raw materials to the mixing chamber of the above-mentioned mixing apparatus, for example, the apparatus shown in FIG. 1 is known. According to this, the electric control section 1 controls the hydraulic control section 2, and the mixing device 3
The first drive cylinder 4a and the second drive cylinder 4b are operated in accordance with the mixing operation. Then, the first
The first liquid plastic raw material sucked by the raw material supply piston cylinder 5a from the first raw material storage tank 6a through the flow path 7a and the switching valve 8a is communicated with the mixing chamber (not shown) of the mixing device 3 through the flow path 9a. At the same time, the second raw material supply piston cylinder 5b sucks the second liquid plastic raw material from the second raw material storage tank 6b through the flow path 7b and the switching valve 8b into the flow path 9b. a second chamber (not shown) of the mixing device 3;
The raw material is supplied to the raw material supply port 10b. At this time, the forward speed of the piston 11a of the first raw material supply piston cylinder 5a, that is, the supply speed of the first liquid plastic raw material is controlled by the hydraulic control unit 2 to the first flow rate regulating valve 1.
2a to the first drive cylinder 4a, and the forward speed of the piston 11b of the second raw material supply piston cylinder 5b,
That is, the supply speed of the second liquid plastic raw material is controlled by the flow rate of pressure oil sent from the hydraulic control section 2 to the second drive cylinder 4b via the second flow rate regulating valve 12b. In addition, 14a in FIG. 1 is the first
The liquid plastic raw material is transferred to the first raw material storage tank 6a.
14b is a flow path for returning the second liquid plastic raw material to the second raw material storage tank 6b. By the way, in the above-mentioned supply device, once the first flow rate regulating valve 12a and the second flow rate regulating valve 12b are adjusted, the supply speed of the first liquid plastic raw material and the second liquid plastic raw material is always constant. That is, from the start of supply to the end of supply, it is always supplied at a constant speed. Therefore, the injection speed of the mixed components injected into the mold from the mixing chamber (not shown) of the mixing device 3 is also constant. Therefore, the mixture ratio injected into the mold is constant, the physical properties are uniform within one molded product, and it is impossible to intentionally create parts with different physical properties within one molded product. It is. However, due to the recent diversification of demand for plastic products and rationalization of production, it has become necessary to have different physical properties within a single plastic molded product. For example, liquid container caps are sometimes provided with a soft material packing on the top of the inner surface of the cap to improve sealing performance, but if this could be formed integrally with the cap at the same time as the cap is molded, there would be many advantages in manufacturing the container. It will be done. This invention was made in view of the above circumstances,
When supplying raw materials using the raw material supply device of a multi-component liquid plastic raw material mixing device, in which a raw material supply piston cylinder is arranged in each supply channel connecting each raw material storage tank and each raw material supply port of the mixing device,
The movement position of the piston of at least one raw material supply piston cylinder is detected by a detector, and the raw material supply piston cylinder is controlled based on the detection signal of the detector to change the raw material supply speed, thereby controlling the raw material supply ratio. is configured to change between the start of raw material supply and the end of supply. Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 2 shows an example of an apparatus suitable for carrying out the raw material supply method of the present invention, and the same components as those in FIG. In this embodiment, the first electromagnetic flow regulating valve 16a is used to control the flow rate of pressure oil sent from the hydraulic control section 2 to the first drive cylinder 4a, and the second A second electromagnetic flow control valve 16a is used to control the flow rate of pressure oil sent to the drive cylinder 4b. Further, a first detector 19a is provided to detect the forward speed and position of the piston 18a of the first raw material supply piston cylinder 17a, and a first detector 19a is provided for detecting the forward speed and position of the piston 18a of the first raw material supply piston cylinder 17a.
A second detector 19b is provided to detect the forward speed and position of the piston 18b. Furthermore, the electric control unit 20 is set with the forward speed of the piston 18a of the first raw material supply piston cylinder 17a and the piston 18b of the second raw material supply piston cylinder 17b, the speed switching point, and the forward speed ratio of the pistons 18a and 18b. A setting device 21 is provided. Note that the first electromagnetic flow rate adjustment valve 16a and the second electromagnetic flow rate adjustment valve 16b are controlled by control signals from the electric control section 20. In addition, the first
The detection signal of the detector 19a and the detection signal of the second detector 19b are input to the electric control section 20. Setting device 2 of the raw material supply device configured in this way
1. The forward speed of the piston 18a of the first raw material piston cylinder 17a, depending on the physical properties required for each part of the plastic molded product to be molded;
The speed switching point and raw material supply ratio are set as shown in the following table, for example.

[Table] Second raw material supply amount
(Note) Raw material supply ratio=

Claims (1)

[Claims] 1. When supplying raw materials using a raw material supply device of a multi-component liquid plastic raw material mixing device in which a raw material supply piston cylinder is arranged in each supply channel connecting each raw material storage tank and each raw material supply port of the mixing device, at least The moving position of the piston of one raw material supply piston cylinder is detected by a detector, and the raw material supply piston cylinder is controlled based on the detection signal of the detector to change the raw material supply speed, thereby controlling the raw material supply ratio. A raw material supply method for a multi-component liquid plastic raw material mixing device characterized by changing the raw material supply from the start of raw material supply to the end of supply.