JPH01110925A - Temperature detecting method of injection molding machine - Google Patents

Abstract

PURPOSE:To perform high-precision and exact temperature detection by preventing the offset of temperature, by calculating the temperature of the other position through arithmetic processing based on the measured temperatures at two positions. CONSTITUTION:A temperature sensor 10 of a heater 6 is removed from a temperature detecting part P1 and mounted on a temperature detecting part Ps positioning to the rearmost part of the heater 6 capable of detecting a part where a temperature gradient is high. Temperatures of the temperature detecting parts Ps, P2 are detected by the temperature sensors 10, 11 and detected data are given to an arithmetic processing part 20. The temperature of the temperature detecting part P1 is calculated by the arithmetic processing part 20 through operational treatment. Although offset becomes apt to generate on a temperature distribution when a part where the temperature gradient becomes extremely high exists on the temperature detecting part, the temperature on the inside of a space between both the detecting parts Ps P2 can be estimated by removing the one temperature sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a temperature detection method for an injection molding machine equipped with a plurality of arrayed temperature detection sections.

[Conventional technology]

FIG. 3(a) shows an injection device M in a general in-line screw type injection molding machine. The injection device M includes a heating cylinder 4 having an injection nozzle 2 at its tip and a hopper 3 connected to its rear end, and a screw 5 is inserted into the heating cylinder 4. On the other hand, the heating cylinder 4 is connected from the hopper 3 side to the feed zone Zf,
Compression zone Zc, metering zone Zm
Each zone is divided into an appropriate set temperature (200
Three heaters 6, 7, and 8 are connected to the heating tube 4 to heat the
It is provided on the outer periphery of the The temperature distribution by each of these heaters 6, 7, 8 has the characteristics shown by the solid line in FIG. In addition, as shown in Fig. 1, temperature detection parts P11P2 and P3 are set in the middle of each heater 6.7.8, and a temperature sensor (
Temperature was detected using a 10°11.12 thermocouple and maintained at a predetermined set temperature through feedback control.

The granular molding material is supplied from the hopper 3 to the feed zone Zf, heated and transferred along the inner surface of the heating cylinder 4 and the screw groove by the rotation of the screw 5, and sent to the compression zone Zc.

Then, in the same zone Zc, it is melted and plasticized by heating by a heater and shear heat generated by compression, and further, it is thoroughly kneaded in the metering zone Zm, and is accumulated and metered in front of the screw 5.

[Problem that the invention seeks to solve]

However, the conventional temperature detection method described above has the following problems.

The feed zone Zf of the heating cylinder 4 is heated to a considerably high temperature by the heater 6, and a cooling water channel is provided in a portion communicating with the adjacent hopper 3 so that the molding material is smoothly supplied from the hopper 3 to the feed zone Zf. 15 for cooling. Therefore, the temperature distribution in this vicinity has an extremely large temperature gradient as shown in FIG. 3(b). As a result, the cooling portion takes away a large amount of heat from the rear part of the adjacent heater 6, and accordingly, the amount of power supplied to the heater 6 increases, and the front part of the heater 6 becomes overheated.

Therefore, as shown by the imaginary line in Figure (b), an offset S occurs with respect to the original set temperature distribution, and in the end, this phenomenon becomes a major factor that hinders highly accurate and accurate temperature detection and temperature control. .

Although the problem of detection accuracy can be solved by increasing the number of temperature sensors and adopting a multi-point detection method, this increases the number of parts and makes the configuration undesirable.

[Means for solving problems]

The present invention aims to provide a temperature detection method for an injection molding machine that solves the problems existing in the prior art described above.
This is achieved by the detection method shown below.

That is, the temperature detection method for an injection molding machine according to the present invention detects the temperature at at least three arbitrary points, for example, the temperature detection sections Ps and P2, when detecting the temperature at the plurality of temperature detection sections Ps, PI, P2, and P3. It is characterized in that the temperature is detected by actual measurement, and other temperature detection units, such as PI, are detected by calculation based on this actual measurement.

[For production]

Next, the operation of the present invention will be explained.

Since the temperature detection method according to the present invention actually measures the temperatures of the temperature detection parts Ps and P2 at at least three locations, it is possible to determine the temperature gradient between the rain detection parts. On the other hand, the temperature of the unknown temperature detecting section P1 can be calculated (estimated) by arithmetic processing because its positional relationship with respect to the temperature detecting sections Ps and 22 is known.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

Figure 1 is a layout diagram of the temperature detection section based on the method of the present invention, Figure 2
The figure is a block system diagram of a temperature detection system for implementing the method of the present invention, and FIG. 3 is a diagram showing the injection device and temperature distribution characteristics of each part shown in longitudinal section.

First, the heaters 6.7.8 in FIG. 1 correspond to the same numbers of the heaters shown in FIG. 3, and are mounted on the heating cylinder 4 in the injection device. In the method of the present invention, the temperature sensor attached to the heater in a region with a large temperature gradient, that is, the temperature sensor 10 of the heater 6 adjacent to the hopper 3 is connected to the heater 6 that can detect a region with a large temperature gradient from the conventional temperature detection section P1. The temperature detection section Ps is located at the rearmost part of the temperature detection section Ps.

Then, the temperature detection section P is detected by the temperature detection system shown in FIG.
s and P2 are detected by temperature sensors 10 and 11,
The detected data is provided to the arithmetic processing unit 20. In this arithmetic processing unit 20, for example, temperature gradient data (straight line or arbitrary function curve) between rain detection units is stored as a database.
Furthermore, based on the position data of the temperature detecting section PI, the temperature of the detecting section PI is calculated by arithmetic processing.

In this way, when detecting the temperature in multiple temperature detection parts, if there is a part where the temperature gradient is extremely large, an offset is likely to occur in the temperature distribution. By transferring, a temperature distribution state with a large temperature gradient can be obtained as a function or as a database. Therefore, it is possible to estimate the ambient temperature of any temperature detecting section on the inside between the rain detecting sections or on the outside of both the detecting sections.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments.

For example, although the temperature detection sections at three locations are actually measured, it is possible to actually measure the temperature detection sections at three or more locations, and the temperatures of any other number of temperature detection sections can be calculated simultaneously or individually. Furthermore, although the heating cylinder is illustrated, the present invention can also be applied to other parts configured under similar conditions, such as a mold. Other changes may be made in the detailed configuration, number I, method, etc., without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, the temperature detection method for an injection molding machine according to the present invention detects the temperature at two arbitrary locations by actual measurement, and calculates the temperature at another location based on the actual measurements, so that the following method can be used. achieve great effect.

- Temperature offset in areas adjacent to areas with large temperature gradients can be prevented, and highly accurate and accurate temperature detection and furthermore temperature control can be performed.

■ No additional parts are required, resulting in low cost, and it can be handled by changing the program, making it easy to implement and highly versatile.

[Brief explanation of the drawing]

Figure 1: Layout diagram of the temperature detection unit based on the method of the present invention, Figure 2: Block system diagram of the temperature detection system for carrying out the method of the present invention, Figure 3: Injection device shown in longitudinal section and various parts. Temperature distribution characteristic diagram. Also in the drawing. Ps, PI, P2. P3: Temperature detection unit patent applicant
Nissei Jushi Kogyo Co., Ltd. Patent Attorney (Part 2) 1) Shigeru Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a temperature detection method for an injection molding machine having multiple temperature detection parts, the temperature of at least two arbitrary temperature detection parts is actually measured, and the temperature of at least one other arbitrary temperature detection part is detected based on the measured temperature. A temperature detection method for an injection molding machine, characterized in that temperature is detected by calculation.