JP2001150485A - Mechanism for adjusting flow rate of supercritical fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply supercritical fluid automatically to an injection cylinder by extruding the fluid intermittently by using an extrusion tank having a pair of cutoff valves. SOLUTION: A mechanism for adjusting the of supercritical fluid has the first cutoff valve 6 fitted to the inlet 3 of the extrusion tank 1, the second cutoff valve 8 communicating with an injection machine cylinder 7 fitted to the outlet 8a of the tank 1, a driving part 10 for actuating the piston 9 of the tank 1, a position detection part 11 for detecting the position of the piston 9, a heater 2 for heating the tank 1, and a control part 12 connected with the cutoff valves 6, 8, the driving part 10, the position detection part 11, and the heater 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for adjusting a flow rate of a supercritical fluid, and more particularly, to a mechanism for controlling the flow rate of a supercritical fluid in an injection molding machine while controlling the temperature and pressure of the supercritical fluid. The present invention relates to a novel improvement to enable quantitative supply.

[0002]

2. Description of the Related Art Conventionally, when a supercritical fluid is supplied to a molding machine, for example, as disclosed in Japanese Patent No. 2625576, the supercritical fluid is continuously supplied to continuously produce a foamed molded article. Was.

[0003]

Since the conventional supercritical fluid supply device is configured as described above, there are the following problems. That is, the density of the supercritical fluid changes greatly depending on the temperature and pressure, but when it is supplied to the extruder, it is continuous as described above. However, when supplying to an injection molding machine, the injection molding machine itself is in an intermittent operation, so the screw retreats and keeps the supply amount constant during injection. Supply had to be stopped, and as a result, quantitative control of the supply amount was impossible.

[0004] The present invention has been made to solve the above-mentioned problems, and in particular, when an injection cylinder is subjected to foam molding with an injection molding machine, the temperature and pressure of a supercritical fluid are controlled in an injection cylinder. It is an object of the present invention to provide a flow control mechanism of a supercritical fluid which can be intermittently supplied at a constant rate.

[0005]

According to the present invention, there is provided a supercritical fluid flow rate adjusting mechanism provided at an inlet of an extrusion tank.
A shut-off valve, a second shut-off valve provided at an outlet of the extrusion tank and communicating with an injection machine cylinder, a driving unit for operating a piston of the extrusion tank, a position detection unit for detecting a position of the piston, A heater for heating the tank, and a control unit connected to the first and second shut-off valves, a driving unit, a position detector, and a heater, and a supercritical fluid supplied through the first shut-off valve is provided. Hold in the extrusion tank and adjust the temperature and pressure of the supercritical fluid,
The second shut-off valve is opened to supply intermittently into an injection machine cylinder, and the control unit is configured to receive injection machine status data of the injection machine. The supercritical fluid has a configuration made of a liquid.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a supercritical fluid flow rate adjusting mechanism according to the present invention will be described below with reference to the drawings. 1 is a heater 2
A first shutoff valve 6 for controlling whether to supply or shut off the supply of the supercritical fluid 5 from the supercritical generator 4 is provided at the inlet 3 of the extrusion tank 1. .

The lower outlet 8a of the extrusion tank 1
A second method for supplying the supercritical fluid 5 to the injection machine cylinder 7
A shut-off valve 8 is provided, and a piston 9 in the extrusion tank 1 is provided.
Is connected to a drive unit 10 which is operated by hydraulic pressure or the like.
The extrusion tank 1 is provided with a position detector 11 for detecting a stroke position of the piston 9, and the first shutoff valve 6, the heater 2, the second shutoff valve 8, and the position detector 11 are provided.
The drive unit 10 is connected to a control unit 12 to which injection machine status data 13 of an injection molding machine (not shown) is input.

Next, the operation will be described. First, the second shut-off valve 8 is connected to the injection machine cylinder 7 of the injection molding machine, and various injection machine status data 13 corresponding to foam injection are stored in the control unit 1.
When the setting is completed by inputting to the control unit 2, the control unit 12 opens the first shut-off valve 6, detects the position of the piston 9 by the position detection unit 11 while raising the piston 9, and stores the position in the extrusion tank 1. A fixed amount of supercritical fluid 5 is stored. Thereafter, by controlling the temperature of the heater 2 and the back pressure by the drive unit 10 in accordance with the bubbling state, the liquefied supercritical fluid 5 can be obtained.
By opening the shut-off valve 8 and operating the drive unit 10 to depress the piston 9, the predetermined amount of the supercritical fluid 5 is automatically supplied intermittently to the molten resin in the injection machine cylinder 7 from the outlet 8a. can do.

[0009]

As described above, the mechanism for adjusting the flow rate of a supercritical fluid according to the present invention has the following advantages. That is, since a pair of shut-off valves, a heater, a piston, a position detection unit, and a drive unit are comprehensively controlled by a control unit, the supercritical fluid in the extrusion tank is intermittently set as a condition suitable for foam injection. It can be supplied to the cylinder, and the moldability by foam injection molding can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a supercritical fluid flow rate adjusting mechanism according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extrusion tank 2 Heater 3 Inlet 5 Supercritical fluid 6 First shut-off valve 7 Injector cylinder 8 Second shut-off valve 9 Piston 10 Drive unit 8a Outlet 11 Position detecting unit 12 Control unit 13 Injector status data

Claims (3)

[Claims] 1. A first shut-off valve (6) provided at an inlet (3) of an extrusion tank (1) and an injection machine cylinder (7) provided at an outlet (8a) of the extrusion tank (1). A second shut-off valve (8), and a drive unit (10) for operating a piston (9) of the extrusion tank (1).
And a position detector (11) for detecting the position of the piston (9).
And a heater (2) for heating the extrusion tank (1),
The first and second shut-off valves (6, 8), the drive unit (10), the position detector
(11) and a control unit (12) connected to the heater (2),
The supercritical fluid (5) supplied through the first shut-off valve (6) is held in the extrusion tank (1), and the temperature and pressure of the supercritical fluid (5) are adjusted and the second A supercritical fluid flow rate adjusting mechanism, characterized in that a shutoff valve (8) is opened to supply intermittently into an injection machine cylinder (7). 2. The supercritical fluid flow rate adjusting mechanism according to claim 1, wherein the control unit is configured to receive injection machine status data of the injection machine. 3. The supercritical fluid flow control mechanism according to claim 1, wherein the supercritical fluid is made of a liquid.