JPH0924518A - Molding of thermosetting resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the pull or the deformation from occurring at the time of curing by providing a heating means and a temperature sensor which are used for setting the internal temperature distribution of a molding the in such a manner that both heating means and temperature sensor are scattered, and also providing a means for detecting the degree of curing which uses an ultrasonic wave in order to set the degree of hardness of a resin liquid in such a way that the means is scattered. SOLUTION: If molding dies 2a, 2b are locally heated using a heater 8, data detected by a thermoelectric couple 11 is transmitted to a computer 10 through a thermometer 12. On the other hand, if an instruction for the frequency and the rate of propagation of an ultrasonic wave to be oscillated is given to an ultrasonic wave oscillator 24 by the computer 10, an ultrasonic wave transmitted by an ultrasonic oscillator 13 is received upon the oscillation of the ultrasonic wave 14. In addition, data on the detected ultrasonic waveform is transmitted to the computer 10 by an ultrasonic waveform detector 15. The ultrasonic wave is easily propagated between liquid and a solid and is hardly propagated between the solid and gas. Further, the propagation speed of the ultrasonic wave is higher in the solid than in the liquid. Therefore, the characteristic change is detected by correcting the temperature, and data on the detected ultrasonic wave and the detected temperature transmitted to the computer 10 are analyzed, and the analytical results control a heater power supply control part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin molding apparatus, and is intended to prevent sink and deformation of the cured resin.

[0002]

2. Description of the Related Art A thermosetting resin as a molding resin is manufactured by the following procedure. First, as shown in FIG. 5 (a), an epoxy resin, a filler, and a curing agent are mixed to form a resin liquid 1, and then the resin liquid 1 is introduced into a mold 2 as shown in FIG. 5 (b). After being injected, the mold 2 is put into the heating furnace 3 as shown in FIG. Resin liquid 1
When is cured, as shown in FIG. 5 (d), the mold 2 is removed, and the mold resin 4 which is not completely cured is taken out.
As shown in FIG. 5 (e), it is put into the heating furnace 5 and secondarily heated at a temperature higher than the first heating. At this time, the support member 7
The mold resin 4 is held and heated by a and 7b so as not to be deformed. Then, finally, the mold resin 4 is cooled by the fan 6.

Here, in the primary heating of FIG. 5 (c), since the temperature of the thin-walled portion rises faster than the other portions, it is cured first, and the resin liquid of the thick-walled portion is thin. When it is pulled by a part, a sink mark or deformation that is a depression is generated in the thick part. The sink mark and the deformation occur more frequently as the size of the mold resin increases.

For this reason, it is necessary to measure the temperature distribution of the mold, grasp the heat curing state of the resin liquid inside the mold at any time, and appropriately control the temperature distribution of the mold.

[0005]

However, it is difficult to detect the curing state of the resin liquid inside the mold at any time, and after the resin liquid has hardened, the mold resin is taken out of the mold to determine whether the temperature distribution control is appropriate. Must. Therefore, when a new mold is manufactured for that purpose, the mold resin must be trial-manufactured many times to find the optimum conditions.

Therefore, an object of the present invention is to provide a thermosetting resin molding apparatus that solves the above problems.

[0007]

The invention according to claim 1 is
While the heating means and the temperature sensor are dispersedly provided so that the temperature distribution in the mold can be set, the curing degree detecting means using ultrasonic waves is dispersedly provided in order to know the degree of curing of the resin liquid. Characterize.

According to the second and third aspects of the invention, in order to prevent the resin liquid in the vicinity of the sprue from rapidly rising in temperature and being hardened, the material of the mold in the vicinity of the sprue is made of a material having a small thermal conductivity. Alternatively, a flow path for flowing the cooling liquid is formed in the vicinity of the sprue in the mold.

The invention according to claim 4 is characterized in that, when the metal is implanted in the resin, the heating means is provided in the vicinity of the metal whose temperature rises slowly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

(A) Example 1 The construction of a thermosetting resin molding apparatus according to the present invention is shown in FIG. As shown in the figure, the mold 2 is composed of a mold 2a and a mold 2b and is housed in a heating furnace 16 as a constant temperature furnace, and a heater 8 as a heating means for locally heating the mold 2 is used. The heaters 8 are embedded in the upper, middle, and lower portions of the heaters 2a and 2b, and the heater 8 is connected to the computer 10 via a heater power source control unit 9 that controls the power source of the heater 8. Then, in order to measure the temperature distribution of the mold 2, on the molds 2a and 2b,
Thermocouples 11 as temperature sensors are embedded in the middle and bottom, and each thermocouple 11 is connected to the computer 10 via a temperature measuring device 12.

Further, in order to measure the process in which the resin liquid heated by the heater 8 changes from a liquid to a solid, a curing degree detecting means is provided. That is, on the mold 2b,
An ultrasonic oscillator 24 is provided on the outer surfaces of the inside and the bottom, and the ultrasonic oscillator 13 generates ultrasonic waves.
While being connected to the computer 10 via the mold 2a
An ultrasonic receiver 14 is provided at a position facing the ultrasonic transmitter 13 on the upper, middle, and lower outer surfaces, and the ultrasonic receiver 14 is connected to the computer 1 via an ultrasonic waveform detector 15.
Connected to 0.

The operation of the thermosetting resin molding apparatus will be described below. When the heaters 8 heat the molds 2a and 2b to the extreme parts, the data detected by the thermocouple 11 is changed to the temperature measuring device 12.
Is transmitted to the computer 10 via. On the other hand, when the computer 10 gives an instruction to the ultrasonic oscillator 24 about the frequency and amount of propagation of the ultrasonic wave, the ultrasonic wave generated by the ultrasonic oscillator 24 and emitted from the ultrasonic transmitter 13 is transmitted to the ultrasonic receiver 1.
4 is received, and the detection data of the ultrasonic waveform by the ultrasonic waveform detector 15 is transmitted to the computer 10.

Here, the ultrasonic waves are well propagated between the liquid and the solid, but are difficult to propagate between the solid and the gas, so that the portion where the sink mark is generated is difficult to propagate, and the occurrence of the sink mark can be detected. . Although the propagation velocity of ultrasonic waves is faster in a solid than in a liquid, the propagation velocity also changes with temperature, so temperature compensation is performed to detect changes in physical properties. The resin, which is a polymer substance, has a large change in the propagation speed when it changes from liquid to solid, but it is used because the propagation speed is greatly affected by the mixing of curing agents and fillers and the temperature and frequency. It is necessary to know the characteristics of the resin in advance.

Since the change of the resin liquid can be perceived from the state of ultrasonic waves in this manner, the ultrasonic wave propagation speed, propagation amount, and frequency distribution are measured while heating the molds 2a and 2b by the heater 8 at the extreme portions, The resin liquid is gradually cured from the outside of the lower portion of the mold 2. Then, the detected data of the ultrasonic waveform and the detected temperature transmitted to the computer are analyzed, and the heater power supply controller 9 is controlled. When the resin liquid on the outer side of the lower part hardens, the resin liquid contracts and runs short of the resin liquid, so that the resin liquid accumulated in the upper sprue is replenished.

(B) Second Embodiment Next, a second embodiment of the thermosetting resin molding apparatus according to the present invention is shown in FIG. This is because the hardening time of the resin liquid in the vicinity of the sprue is short, so that a portion having a large wall thickness thereunder is pulled to cause sink marks, so that the hardening time of the resin liquid is delayed.

As shown in the figure, the vicinity of the sprue in the molds 2a, 2b is formed of, for example, ceramics 2c, 2d having a small thermal conductivity except the vicinity of the inner surface.

In such a thermosetting resin molding apparatus, the mold 2 is used.
Since heat is less likely to be transmitted to the ceramics 2c and 2d than to a and 2b, heat is less likely to be transmitted to the resin liquid in the vicinity of the sprue which is the resin liquid surrounded by the ceramics 2c and 2d. Therefore, the curing speed of the resin liquid in the vicinity of the sprue becomes substantially the same as that of the other portions, and the occurrence of sink marks is prevented.

(C) Third Embodiment Next, a third embodiment of the thermosetting resin molding apparatus according to the present invention is shown in FIG. Also in this embodiment, the curing time of the resin liquid near the sprue is delayed.

As shown in the figure, in the vicinity of the sprue in the molds 2a, 2b, a flow path 2 for flowing cooling water as cooling means.
e, 2f are formed.

In the thermosetting resin molding apparatus, the flow path 2 is used.
When the molds 2a and 2b are heated while flowing water into the molds 2e and 2f, the vicinity of the sprue of the molds 2a and 2b becomes the flow paths 2e and 2b.
Heat is taken away by the water flowing through f. Therefore, the speed at which heat is transferred to the resin liquid in the vicinity of the sprue becomes slow. For this reason,
The curing time of the resin liquid in the vicinity of the sprue becomes almost the same as that of other portions, and sink marks are prevented.

(D) Fourth Embodiment Finally, a fourth embodiment of the thermosetting resin molding apparatus according to the present invention.
Is shown in FIGS. 4 (a) and 4 (b). In this example, when there is a metal embedded in the resin, it is possible to prevent peeling between the surface of the metal and the resin due to the hardening delay of the resin liquid caused by the heat being absorbed by the metal. It was done.

As shown in the figure, the molds 18a and 18b
A split mold 18 is provided, and a conductor 19 for embedding it inside the resin is provided. That is, the mold 18
Circular recesses 20 and 21 are formed at the centers of the inner surfaces of a and 18b, respectively, and both ends of the conductor 19 are fitted into the recesses 20 and 21, respectively. A heater 22 is provided inside the molds 18a, 18b near the recess 20 as a heating means for quickly hardening the resin liquid 23 around the conductor 19.

In such a thermosetting resin molding apparatus,
The conductor 19 is set in the mold 18 and the resin liquid 23 is set in the mold 1.
The heater 22 is energized when the resin liquid 23 is filled into the heating furnace 8 and then cured in the heating furnace. Then, since the conductor 19 is heated by the heater 22, the temperature of the resin liquid 23 around the conductor 19 also rises and the resin liquid 23 is hardened almost at the same time as the other portions. Therefore, the hardening and shrinkage of the resin liquid due to the delay in the temperature rise of the resin liquid 23 around the conductor 19 and the peeling between the conductor 19 and the resin due to the shrinkage are prevented.

Although Examples 2 to 4 relate to the improvement of the mold, they can be combined with Example 1.
Further, the material having a low thermal conductivity in Example 2 is not limited to ceramics and may be any material having a thermal conductivity lower than that of the material of the mold. Furthermore, Example 3
Instead of the cooling water, another cooling liquid may be caused to flow.

[0026]

As can be seen from the above description, claim 1
According to the thermosetting resin molding apparatus according to the above, since the degree of curing detection means for knowing the state of propagation of ultrasonic waves, the heating means, and the temperature sensor are provided, the state of thermosetting of the resin liquid is grasped at any time,
It is possible to properly control the temperature distribution of the mold. Therefore, even if the size of the resin becomes large, it is possible to prevent the occurrence of sink marks and deformation due to shrinkage during curing.

According to the thermosetting resin molding apparatus of the second and third aspects, the vicinity of the sprue of the die is formed of a material having a small thermal conductivity, or a passage for flowing a cooling liquid is provided near the sprue to form the sprue. Since the temperature rise of the resin liquid in the vicinity of is delayed, it is possible to prevent the occurrence of sink marks due to the hardening in the vicinity of the sprue first.

According to the thermosetting resin molding apparatus of the fourth aspect, since the heating means for heating the metal embedded in the resin is provided, the resin liquid shortage due to the delay of the curing of the resin liquid in the vicinity of the metal occurs. As a cause, it is possible to prevent the adhesion portion between the metal and the resin from peeling off due to curing shrinkage of the resin.

[Brief description of drawings]

FIG. 1 is a first embodiment of a thermosetting resin molding apparatus according to the present invention.
FIG.

FIG. 2 is a second embodiment of a thermosetting resin molding apparatus according to the present invention.
Sectional drawing which shows the metal mold | die in FIG.

FIG. 3 is a third embodiment of the thermosetting resin molding apparatus according to the present invention.
Sectional drawing which shows the metal mold | die in FIG.

FIG. 4 is a fourth embodiment of the thermosetting resin molding apparatus according to the present invention.
FIG. 2A is a sectional view, and FIG.
AA arrow view of FIG.

FIG. 5 is an explanatory view showing a conventional procedure for molding a thermosetting resin.

[Explanation of reference numerals] 2, 2a, 2b, 18, 18a, 18b ... Molds 2c, 2d ... Ceramics 2e, 2f ... Flow path 8, 22 ... Heater 10 ... Computer 11 ... Thermocouple 13 ... Ultrasonic transmitter 14 ... Ultrasonic receiver 15 ... Ultrasonic waveform detector 16 ... Heating furnace 19 ... Conductor 23 ... Resin liquid

Claims (4)

[Claims] 1. A heating means for heating an extreme part is dispersed and provided on a mold, and a plurality of temperature sensors for measuring the temperature distribution of the mold are provided, and a transmitter for transmitting ultrasonic waves and a receiver for receiving ultrasonic waves. A thermosetting resin molding device, characterized in that a curing degree detecting means composed of a waveform detector connected to a receiver and a receiver is provided in a dispersed manner. 2. A thermosetting resin molding apparatus, characterized in that the vicinity of the gate of the mold is made of a material having a lower thermal conductivity than that of the mold. 3. A thermosetting resin molding apparatus characterized in that a flow path for flowing a cooling liquid is formed in the vicinity of a gate of a mold. 4. A thermosetting resin molding apparatus characterized in that a heating means for heating a metal to be implanted inside the resin by hardening the resin is provided in a mold.