JP3109985B2 - Mold temperature measuring device for injection molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to y de mold temperature measuring device.

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional injection mold having a thermocouple has a sprue 11 of a fixed mold 101. As shown in FIG.
3 and an insertion hole 105 in a portion that does not interfere with the cooling water pipe 111.
And the temperature detecting portion 103a of the thermocouple 103 held by the holder provided with the fixing joint 107 and the fixing adapter 108 is inserted into the insertion hole 105.
An insertion hole 106 is provided in a portion of the movable mold 102 that does not interfere with the cooling water pipe 112, and the temperature of the thermocouple 104 held by a holder provided with a fixing joint 109 and a fixing adapter 110 in the insertion hole 106. The detection unit 104a is inserted.

[0003]

In an injection molding machine, when the outside air temperature fluctuates, its influence appears directly on the mold surface temperature. For example, when the outside air temperature decreases, the mold surface temperature, that is, the cavity surface temperature and the core surface temperature decrease. If the molten resin is injected and filled into the cavity by performing mold clamping in this state, the amount of temperature drop of the molten resin when the molten resin comes into contact with the surfaces of the cavity portion and the core portion, when the outside air temperature does not decrease, As a result, the resin is not sufficiently supplied to every corner in the cavity. As a result, there is a possibility that molding defects such as sink marks and distortions appearing in the molded product and a decrease in weight and dimensions of the molded product as compared with non-defective products may occur. Such a surface temperature of the cavity and the core cannot be measured by directly attaching a temperature sensor to the cavity and the core. This is because the surface of the cavity and the surface of the core provide the surface shape of the molded product as it is, and the appearance of the molded product is hindered when the temperature sensor is attached.

However, in the above-mentioned conventional technology, the temperature detecting portion of the thermocouple inserted into the insertion hole is easily affected by the heat flux due to the cooling water in the cooling water pipe and the resin in the cavity, and the above-mentioned fluctuation of the outside air temperature is caused. Since it is not possible to quickly and accurately detect a change in the mold surface temperature due to the above, molding failure may occur. In addition, it is necessary to perform a drilling process for forming an insertion hole in the mold, and it is necessary to prepare a fixing joint, a fixing adapter, and the like for mounting a thermocouple, so that the manufacturing cost increases. There is a problem.

The present invention has been made in view of the above-mentioned problems of the prior art, and has been made in consideration of a temperature change similar to a temperature change of a surface of a mold cavity or a surface of a mold core due to a change in outside air temperature. it is possible to quickly and accurately detect the change in the mold wall temperature indicated, it is an object to realize a production cost that can <br/> at reduced injection mold temperature measuring device.

[0006]

In order to achieve the above object, a mold temperature measuring apparatus for injection molding according to the present invention has a heat medium flow passage through which a heat medium for adjusting a mold temperature flows. and the mold was not affected by the heat flux caused by the heat medium flowing through the heat medium passage in the outer wall surface of the mold, yet the change in outside air temperature is the temperature detection unit directly affects the site <br/> and anchored thermocouple detected by said thermocouple test
An A / D converter for converting an output value into a digital signal;
Sequence the digital signal sent from the / D converter
Sampling is performed based on the timing signal sent from the controller.
Ring and store as sampling value and
Convert the sampling value to a numerical value or graph and display it on the display
An arithmetic processing unit that outputs a display signal for display
It is characterized in that the. Further, it is effective to attach the thermocouple by attaching the adhesive tape to the outer wall surface of the mold while the temperature detecting portion is sandwiched between the outer wall surface of the mold and the adhesive tape.

Further, the thermocouple may be mounted by burying a temperature detecting portion of the thermocouple in a state where at least a part of the temperature detecting portion is exposed from the back surface, and screwing the mounting plate to an outer wall surface of the mold. The thermocouple may be attached by screwing the presser plate to the outer wall surface of the mold with the temperature detector interposed between the outer wall surface of the mold and the presser plate.

[0008]

The mold side wall surface, which is the outer wall surface of the mold, is located at a position different from that of the cavity and the core, but the surface temperature drops due to a decrease in the outside air temperature is the same as the surface of the cavity and the core. It is expected that the temperature change of the surface of the cavity and the core due to the change of the outside air temperature will show a tendency similar to the temperature change of the mold side wall surface. That is, if the surface temperature change of the mold side wall surface is detected, it is expected that the change tendency of the surface temperature of the cavity portion and the core portion can be predicted from this, and as a result, the change tendency of the molded product quality can be predicted.

Further, since there is no influence of the heat flux due to the heat medium flowing through the heat medium flow path provided in the mold, the fluctuation of the mold surface temperature due to the fluctuation of the outside air temperature can be detected quickly and accurately. . As a result, it is possible to predict in advance the occurrence of molding failure of the molded article due to the fluctuation of the mold surface temperature and take an appropriate countermeasure.

Further, since it is not necessary to provide an insertion hole for inserting the temperature detecting portion of the thermocouple into the mold, the manufacturing cost can be reduced.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

[0012] Figure 1 is an explanatory diagram showing an example of an injection molding machine in the present invention using the engagement Ru injection mold temperature measuring device.

A mold M attached to a mold clamping device (not shown)
Is provided with a heat medium flow path (not shown) through which the heat medium flows, and is controlled to a predetermined temperature by a mold temperature controller 8 connected to the heat medium flow path through pipes 5 and 6. The mold temperature of the mold M can be adjusted by circulating the supplied heat medium. The mold M may be either a fixed mold or a movable mold.

A temperature detecting section of the thermocouple 3 is provided on a portion of the outer wall surface of the mold M which is not affected by the heat flux from the heat medium flowing through the heat medium flow path and is directly affected by a change in the outside air temperature. 3a is fixed, and the detection value of the thermocouple 3 is amplified by the amplifier 7, then converted into a digital signal by the A / D converter 2, and sent to the arithmetic processing unit 1.

Here, the arithmetic processing unit 1 includes an A / D converter 2
The digital signal sent from the sequence controller 9
In addition to having a function of sampling based on the timing signal sent from the controller and storing it as a sampling value, and converting the sampling value into a numerical value or a graph and outputting a display signal for displaying on the display 4 ,
It has a function of transferring the sampling value to the temperature control unit of the mold temperature controller 8 and the control unit 10 of the injection molding machine.

Next, a mold thermometer for injection molding according to the present invention.
An embodiment of the mold in the measuring device will be described.

(First Embodiment) As shown in FIGS. 2 and 3, a mold M of the present embodiment comprises a fixed mold 22 having a cavity 22a communicating with a sprue 22c, and a core 23a. Movable mold 2
Consists of three.

The fixed mold 22 is provided with a heat medium passage 2 for flowing a heat medium for adjusting the mold temperature to a predetermined temperature.
A thermocouple 3b is provided on a portion of the outer wall surface of the thermocouple 3b which is not affected by the heat flux due to the heat medium flowing through the heat medium flow path 22b and which is directly affected by a change in the outside air temperature. Is attached by sticking the adhesive tape 21 to the outer wall surface with the temperature detecting portion 3a sandwiched between the outer wall surface and the adhesive tape 21. Similarly, a heat medium flow path 23b for flowing the heat medium is provided in the movable mold 23, and the influence of the heat flux on the outer wall surface due to the heat medium flowing through the heat medium flow path 23b. The thermocouple 3 places the temperature detecting portion 3a between the outer wall surface and the adhesive tape 21 and places the adhesive tape 21 on the outer wall surface at a portion which is not affected by the change of the outside air temperature. It is attached by sticking to.

According to the present embodiment, there is no need to perform processing for mounting the thermocouple 3 on the mold M, and the mounting position of the temperature detector 3a of the thermocouple 3 is not restricted.

(Second Embodiment) As shown in FIG. 4, a mold M according to the present embodiment includes a thermocouple 3
A screw in which the temperature detecting portion 3a is buried in the mounting plate 31 with at least a part thereof exposed from the back surface (the lower surface in the drawing), and which is inserted into a plurality of mounting holes 31a provided in the mounting plate 31 from the front surface side. 32 is attached by screwing and screwing a screw 32 into a screw hole 33 formed on the outer wall surface of the mold M. Except for this point, the second embodiment may be the same as the first embodiment, and a description thereof will not be repeated.

(Third Embodiment) As shown in FIG. 5, a mold M of the present embodiment has a thermocouple 3
With the temperature detecting portion 3a sandwiched between the holding plate 41 and the outer wall surface of the mold M, screws 42 respectively fitted into a plurality of mounting holes 41a provided in the holding plate 41 are attached to the outside of the mold M. It is attached by screwing and screwing into a screw hole 43 formed in the wall surface. Except for this point, the second embodiment may be the same as the first embodiment, and a description thereof will not be repeated.

[0022] For effective check, carried out comparative experiments with the case of using the injection mold with a thermocouple according to the case and the conventional technique using the engagement Ru injection mold temperature measuring device of the present invention Therefore, the result will be described below.

Using polycarbonate as a molding material,
A molded product having a reference weight of 21.60 g was injection-molded in 500 shots over about 12 hours, and the mold temperature was measured for each shot, and the weight of each molded product was measured. The outside air temperature at this time fluctuated in the range of 6.6 ° C.

[0024] Figure 6 is Ru engages the present invention the injection mold thermometer
FIG. 7 shows a graph in which the measured value of the mold temperature measured for each shot and the weight of the molded product in the case of using the measuring device are plotted, and FIG. 7 shows a conventional injection mold having a thermocouple having a thermocouple. 4 shows a graph in which a measured value of a mold temperature measured for each shot and a weight of a molded product are plotted.

As is apparent from FIG. 6, the injection mold temperature measuring apparatus according to the present invention measures the measured mold temperature T from about 200 shots to 500 shots.
While the variation pattern of the w and the variation pattern of the weight Pw of the molded product are almost the same, as is clear from FIG. 7, in the conventional technique, the variation pattern of the measured value Tw of the mold temperature and the variation of the molded product are different. The fluctuation pattern of the weight Pw hardly coincides with each shot.

[0026]

Since the present invention is configured as described above, the following effects can be obtained.

[0027] The cavity portion and the change of the change equivalent mold surface temperature of the core portion surface temperature caused by changes in ambient temperature during elevation-molded can be detected quickly and accurately. As a result, it is possible to quickly and accurately predict, for example, a change in the weight of a molded product due to a change in the outside air temperature and to effectively utilize the quality control of the molded product and control of the molding process. Also, unlike the conventional example, it is not necessary to insert the temperature detection part of the thermocouple into the insertion hole formed in the mold and mount it via a separately-provided fixing joint or fixing adapter. Can be reduced.

[Brief description of the drawings]

It is an explanatory diagram showing an example of an injection molding machine having an injection-molding mold temperature measuring device according to the invention; FIG.

Contact the engagement Ru injection mold temperature measuring device in the present invention; FIG
FIG. 2 is a cross-sectional view showing a first embodiment of a mold to be set .

[Figure 3] Figure 2 shows only the thermocouple and its vicinity in shown to die, (a) represents the schematic partial plan view, (b) in schematic partial cross-sectional view taken along line A-A of (a) is there.

[4] the engagement Ru injection mold temperature measuring device in the present invention our
FIG. 2A is a schematic partial plan view of the second embodiment of the mold according to the present invention, and FIG. 2B is a schematic partial cross-sectional view taken along line AA of FIG.

[5] All the engagement Ru injection mold temperature measuring device of the present invention
FIG. 6A is a schematic partial plan view of a third embodiment of the mold according to the present invention, and FIG. 6B is a schematic partial cross-sectional view taken along line AA of FIG.

6 is a graph showing the correlation between the variation of the measurement values of the mold temperature in the case of using the engagement Ru injection mold temperature measuring device of the present invention and the variations in the weight of the molded article.

FIG. 7 is a graph showing a correlation between a variation in a measured value of a mold temperature and a variation in a weight of a molded product when an injection mold having a thermocouple according to a conventional technique is used.

FIG. 8 is a schematic sectional view showing a conventional injection mold having a thermocouple.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 arithmetic processing unit 2 A / D converter 3 thermocouple 3 a temperature detection unit 4 display 5, 6 pipe 7 amplifier 8 mold temperature controller 9 sequence control device 10 control unit of injection molding machine 21 adhesive tape 31 mounting plate 31 a , 41a Mounting holes 32, 42 Screws 33, 43 Screw holes 41 Holding plate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-31787 (JP, A) JP-A-6-23818 (JP, A) JP-A-63-56409 (JP, A) JP-A-63-56409 236616 (JP, A) Japanese Utility Model sho 59-162216 (JP, U) Japanese Utility Model hei 2-17319 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45 / 84

Claims (4)

(57) [Claims] 1. A heat medium flow path internally provided by mold heating medium for regulating the mold temperature is flowed (M), the heating medium flow path in <br/> outer wall surface of the mold without being affected by the heat flux caused by the heat medium flowing through the, yet the temperature detection unit directly affects the site changes in the outside air temperature is (3a) thermocouple is fixed (3), the detection detected by the thermocouple Value
An A / D converter (2) for converting digital signals into digital signals;
The digital signal sent from the D converter is subjected to sequence control.
Based on the timing signal sent from the control device (9).
Sampling and storing as sampling values
Convert the sampling value into a numerical value or graph and display it
Processing for outputting a display signal to be displayed on the unit (4)
A mold temperature for injection molding characterized by comprising a part (1).
Degree measuring device . 2. A thermocouple (3) having a temperature detector (3).
The adhesive tape (21) was attached to the outer wall surface of the mold (M) in a state where a) was sandwiched between the outer wall surface of the mold (M) and the adhesive tape (21). The mold thermometer for injection molding according to claim 1, wherein
Measuring device . 3. A thermocouple (3) having a temperature detector (3).
a) is buried in the mounting plate (31) in a state where at least a part thereof is exposed from the back surface, and is mounted by screwing the mounting plate (31) to the outer wall surface of the mold (M). The mold temperature for injection molding according to claim 1, wherein:
Measuring device . 4. A thermocouple (3) having a temperature detector (3).
a) was sandwiched between the outer wall surface of the mold (M) and the holding plate (41), and the holding plate (41) was attached to the outer wall surface of the mold (M) by screwing. The injection mold temperature measuring device according to claim 1, wherein: