JPS6183018A - Extruding device - Google Patents

Abstract

PURPOSE:To control temperature in the extruding device correctly by a method wherein a cylinder, constituting the extruding device, is provided with a heater or a cooler while a screw, rotated in the cylinder is provided with a temperature sensor. CONSTITUTION:The cylinder 1, provided with a hopper 2 for throwing a substance to be processed thereinto and a discharging port 3, is arranged with heaters 4, divided into a plurality of pieces, on the outer peripheral surface thereof while the temperature sensor 5a is inserted into the wall of the cylinder 1 immediately below the heater 4. The screw 7, driven by a motor 6, is provided in the cylinder 1 and the temperature sensor 5b is attached to the hollow section of a screw shaft 9 having a screw blade 8. The sensor 5b is connected to a conducting ring 11 through an insulating ring 10 at the rear end of the shaft 9 and is connected further to a controller 13 by brushes 12 whereby the amount of generating heat of the heater 4 may be controlled. According to this method, the correct temperature control in the extruding device may be effected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is a method for pressing a workpiece supplied into a cylinder equipped with a screw under a required temperature condition while stirring the workpiece by the rotation of the screw. This relates to an extrusion device, and particularly relates to temperature detection of a processed material within a cylinder. The present invention is applicable not only to synthetic resin molding machines such as extrusion molding machines, kneading molding machines, and injection molding machines, but also to mixing and conveying rubber, foodstuffs, pharmaceuticals, and chemical agents.

[Prior Art] Taking an extrusion device used in a synthetic resin molding machine as an example, this extrusion device generally mixes the synthetic resin to be processed with additives etc. until it reaches a state suitable for molding. In order to heat and melt the material and supply it to the mold, the cylinder is equipped with a heater and is equipped with a screw for stirring and extruding the material to be processed. The suitability of controlling the temperature of the object to be processed during this extrusion process often has a large effect on the quality of the molded product.

Conventionally, in extrusion equipment, in order to control the temperature of the processed material, a temperature sensor is inserted from the outside of the cylinder to near the inner wall surface of the cylinder, and the temperature near the inner wall surface of the cylinder is detected and detected. This is the most common method of temperature detection.

However, if the temperature sensor is simply inserted into the cylinder wall from the outside, not only will the temperature sensor be directly affected by the conductive heat transmitted from the heater installed in the cylinder to the cylinder, but also the temperature sensor will be directly affected by the radiant heat from the heater. It is also easily affected by outside temperature. For this reason, a difference is likely to occur between the detected temperature and the actual temperature of the object to be processed, making precise temperature control difficult. In particular, when a workpiece with low thermal conductivity is passed through the cylinder at a relatively high speed, the workpiece is less likely to be heated than a normal metal cylinder, which is more susceptible to heat conduction from the heater. The temperature difference widens, making it easier to make mistakes in temperature control.

On the other hand, in order to detect the actual temperature of the processed object as much as possible,
In some cases, a temperature sensor is installed immediately before the discharge port of the extrusion device so that there is no risk of collision with the screw.

However, even though it is possible to accurately know the temperature of the material to be processed at the time of discharge, the temperature inside the cylinder before that cannot be detected, so even if there is a mixing problem due to overheating or insufficient melting in the cylinder, the temperature of the material to be processed at the time of discharge cannot be detected. If the temperature at the time is appropriate, there is a problem that it is impossible to detect these and control the temperature accurately.

The above explanation is based on an extrusion device equipped with a heater, but there are also extrusion devices equipped with both a heater and a cooler for faster temperature control, or only a cooler depending on the type of material being processed. There are also some with , all of which have similar problems.

[Problems to be Solved by the Invention] An object of the present invention is to enable the temperature of a processed material in a cylinder to be detected as a value as close to the actual temperature as possible, and to accurately control the temperature in an extrusion device. is the problem to be solved.

[Means for Solving the Problems] The means taken to solve the above problems in the present invention is to combine a cylinder equipped with one or both of a heater and a cooler, and a screw rotating inside the cylinder. An object of the present invention is to provide an extrusion device in which the screw is equipped with a temperature sensor.

[Function] In the present invention, the screw is surrounded by the object to be processed in the cylinder, so it is not directly affected by conduction heat transmitted through the cylinder from the heater, radiant heat from the heater, etc., and the outside temperature. The temperature sensor installed in the machine can reliably detect the temperature of the surrounding workpiece. In addition, screws are usually made of metal with high thermal conductivity, so instead of installing a temperature sensor on the surface of the screw, it can be installed inside the screw to prevent damage and accurately detect the temperature of the workpiece. can do.

Furthermore, since the screw is provided over almost the entire length of the cylinder, the temperature detection position can be selected from a wide range.

[Example] In Fig. 1, ``■'' is a cylinder, and a hopper 2 for charging the material to be treated is provided at the rear of the cylinder, and a discharge port 3 is formed at the front end. A plurality of heaters 4 are provided on the outer peripheral surface of the cylinder 1 in a plurality of sections in the length direction of the cylinder 1. Further, a temperature sensor 5a is inserted into the wall of the cylinder 1 directly below each heater 4, so that the temperature of the wall surface of the cylinder 1 can be detected.

A screw 7 rotated by a screw motor 6 is provided in the cylinder 1, and the material to be processed that is introduced into the cylinder 1 from the hopper 2 is stirred by a screw blade 8 as the screw 7 rotates. It is heated by a heater 4 while being extruded to a discharge port 3. Further, the screw shaft 9 is hollow, and temperature sensors 5b are provided therein at appropriate intervals in the longitudinal direction.

This temperature sensor 5b serves to detect the temperature of the object to be processed for temperature control.

As the temperature sensor 5b provided on the cylinder 1 and the temperature sensor provided on the screw 7, for example, a thermocouple, a thermistor, etc. can be used.

The number of conductive rings 11 corresponding to the number of temperature sensors 5b is attached to the rear peripheral surface of the screw shaft 9 via an insulating ring 10, and each temperature sensor 5b is electrically connected to a separate conductive ring 11. . Further, for each conductive ring 11, the conductive ring 11
A brush 12 is provided which is in contact with the temperature sensor 5b, and the signal from the temperature sensor 5b is taken out via the guide, the heavy ring 11 and the brush 12.

Each brush 12 is connected to a controller 13, and the controller 13 controls each heater 4 based on a signal from the temperature sensor 5b.
It controls the operation of the That is, the controller 13
compares the temperature detected by the temperature sensor 5b with a preset temperature, increases or decreases the amount of heat generated from the heater 4, and checks whether the increase or decrease is accurate using the temperature sensor 5b. It is something.

In this way, by arranging a plurality of temperature sensors 5b at appropriate intervals in the longitudinal direction of the screw shaft 9, it is possible to accurately detect the temperature state over the entire area inside the cylinder l. In particular, by arranging the heater 4 and the temperature sensor 5b in one-to-one correspondence, it is easier to perform delicate temperature control, and it is also possible to perform control with a predetermined temperature change in the length direction of the cylinder l. can. It is also preferable that the temperature sensor 5b be slidably provided within the screw shaft 9 so that its position can be adjusted by expanding and contracting the electric cord connecting the temperature sensor 5b and the conductive ring 11. Further, the temperature sensor 5b may be placed on the surface of the screw 7, but if it is provided on the surface of the screw 7, it will be easily damaged during operation, so it is not possible to place it inside the screw 7 as in this embodiment. preferable.

In this embodiment, only the heater 4 is provided, but a cooler may be provided along with the heater 4 to speed up temperature control, or depending on the type and application of the workpiece, the heater 4 may be used. Instead, only a cooler may be provided.

In the embodiment shown in FIGS. 2 and 3, the temperature sensor 5b is attached to the tip of a piano wire-shaped guide wire 14 that also serves as an electric cord for transmitting signals, and is installed inside the hollow screw shaft 9. It is provided so that it can be slid. The rear part of the guide wire 14 passes through a guide roller 15 and is connected to the drum 1 while being sandwiched between a capstan roller 16 rotated by a capstan motor (not shown).
It is wrapped around 7. These capstan motor, capstan roller 16, and drum 17 are provided in a case 18 attached to the screw shaft 9, and rotate together with the screw 7.

The rear end of the guide wire 14 and the capstan motor are each electrically connected to a separate conductive ring 11 attached to the screw shaft 9 via an insulating ring 10, and the temperature sensor 5b is in contact with the conductive ring 11. Through the brush 12 that
The capstan motor is also connected to a controller 13 via a brush 12 and a position command device 19. The signal from the temperature sensor 5b is sent to the controller 13 via the guide wire 14, the conductive ring 11 and the brush 12, and the controller 13
The amount of heat generated by each heater 4 is controlled in the same manner as described in FIG. 1 and 2. Further, when a signal from the controller 13 is sent to the position command device 19, the position command device IS operates the capstan motor via the other brush 12 and the conductive ring 11.

When the capstan roller 16 rotates due to this,
The drum 17 rotates to wind up or send out the guide wire 14, and the temperature sensor 5b slides to change its position. In addition, in FIGS. 2 and 3, the same reference numerals as in FIG. 1 indicate the same members.

In this way, temperature control can be performed while detecting the temperature at any position by moving the temperature sensor 5b from time to time, and there is an advantage that the temperature control of the entire cylinder l can be covered by one temperature sensor 5b.

The capstan motor and capstan roller 16
The case 1 containing the drum 17 can also be attached to the motor shaft 20 of the green cream motor 6, as shown in FIG. That is, the guide wire 14 may be passed through the motor shaft 20 by making it hollow, and the rear part of the guide wire 14 may be introduced into the case 18 attached to the motor shaft 20 and wound around the drum 17. In this case, the conductive ring 11 is also usually attached to the motor shaft 20. Also, case 1
8 is a motor shaft 20 that is connected to the screw shaft 9
Although it may be attached to the front part of the motor shaft 20, it is preferable to attach it to the rear part of the motor shaft 20 because the presence of a joint etc. tends to get in the way.

By attaching the case 18 to the motor shaft 20 in this manner, the case 18 can be attached regardless of the diameter or arrangement of the screw shaft 9. In addition, the screw shaft 9
Even when the screw motor 6 is connected to the screw motor 6 via a V-belt, a tow wheel, etc., the pulley shaft 4 is provided with a hollow part,
□It is possible to attach the case 1B to the motor/shaft 20 in the same way.

[Effects of the Invention] According to the present invention, temperature can be detected over a wide range within the cylinder without being affected by direct heat from a heater or the like or the outside temperature, so temperature control can be performed accurately. Can be done. Therefore, deterioration in product quality due to poor temperature control can be prevented, and productivity can also be improved.

[Brief explanation of the drawing]

: Figure 51 is a sectional view showing one embodiment of the present invention, Figure 2 is a sectional view showing another embodiment, Figure 3 is an enlarged sectional view of the vicinity of the case, and Figure 4 is a diagram showing the case attached to the motor shaft. FIG. l: Cylinder, 2: Hopper, 3: Discharge port, 4: Heater (cooler), 5a, 5b: Temperature sensor. 6: Screw motor, 7: Screw, 8: Screw blade, 9 Niscrew shaft, 1o: Insulating ring, 11: Conductive ring, 12: Brush, 13: Controller 1 port: Guide wire, 15 Ni guide roller, 16: Cap Stun roller, 17: drum, 18: case, 19 = position command device, 20; motor shaft.

Claims (1)

[Claims] 1) An extrusion device comprising a cylinder equipped with one or both of a heater and a cooler, and a screw that rotates within the cylinder, and the screw is provided with a temperature sensor.