JPS59187808A - Heating device - Google Patents

Abstract

PURPOSE:To obtain a heating device capable of discharging air effectively from a tablet in a pot by making field intensity larger in the middle of the tablet than at both ends thereof and heating the middle of the tablet at a higher temperature than both ends thereof. CONSTITUTION:The upper electrode 26 is arranged above and nearly in parallel to the lower electrode 11 and the projection of an auxiliary electrode 28 is maximized in the middle 28a and reduced gradually toward both ends 28b, 28b. Rollers 12, 13 are rotated by a motor 22 to revolve the tablets 23, 24, high frequency power is applied between the upper and the lower electrode 26, 11 and the middle part of the tablets united 23, 24 in the longitudinal direction is heated at a higher temperature than both ends. When the tablets 23, 24 are compressed in the pot 8, they change their shape from the middle part and the air around the tablets is discharged and prevented from being sealed into resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heating device for preheating tablets used in transfer molding.

[Background technology]

In the transfer molding method, it is necessary to preheat the tablet (resin mass) that is placed in a pot and compressed with a plunger, and for this reason, the inventor developed and uses a heating device shown in Figure 1. .

That is, this device includes a lower electrode 3 consisting of a pair of rollers 1.2 arranged in parallel, and a lower mold @! above the lower electrode 3. 3 and an upper electrode 4 supported in parallel. Then, the cylindrical tablet 5 is placed on the lower electrode 3 and the roller 1.2 is placed on the lower electrode 3.
By applying high frequency power 6 between the upper and lower electrodes 3 and 4 while rotating the tablet 5 on its axis, the tablet 5 will be heated by electrically-shield heating. The rotation of the tablet 5 causes the tablet to be intensely heated in the circumferential direction.

L = In this heating device, as shown in the same figure, there is a tabret,
, the electric field between i'5 and the upper electrode 4 tends to concentrate at both ends of the tab 1/5 due to the outside of the electric field, and as a result, the tablet is heated more significantly at both ends than at the center. become.

For this purpose, the preheated tablets 5 are placed in the bowl 1 of the transfer molding device 7 as shown in FIG. .

When the two tablets are loaded into the tablet 8 (in the figure, two tablets are loaded) and compressed with the plunger 9, both ends of the tablet are deformed first due to the heating, and this deformation causes the middle part of the tablet to deform. The air of the song will be sealed between the two ends of AI. Therefore, the mold in this condition? T? If this is not done, air will be forced into cavities not shown in the drawings, which will lead to air bubble defects in the molded product.

[Purpose of the invention]

The purpose of the present invention is to heat the tablet to a high temperature even than the central end of a knot, and when the tablet F lr pressure f4i is raised in the pot by kneading, the tablet is raised from the central part, and the air around the tablet is effectively removed. It is an object of the present invention to provide a heating device that can escape and prevent confinement in resin.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, the strength of the electric field generated between the lower electrode and the upper electrode is configured to differ in the length direction of the field, and the tab
The electric field strength 7 at the center of the tab is greater than that at both ends, thereby making it possible to heat the center of the tab to a higher temperature than both ends.

[Example 1] Figure 3 shows a practical example of the present invention. In particular, in this case, two tablets are loaded in series in a pot of a transfer molding device and straw is integrally compressed. The name of the heating device is shown. In the figure, the lower electrode 11 consists of two rollers 12.13 arranged parallel to each other, and the rotation axis 14.15 of each roller 12.13 is supported by a bearing 16.17.
The first few pieces of gear [car 18.19.2
Rotation transmission means 21 consisting of 0 - fixedly installed 2, motor 2
The υ axis is rotated by 2. Then, these rollers have two cylindrical tabs.
3.24 tablets can be placed on the entire surface in a row, and each tablet 23.24 is rotated as the roller 12.13 rotates once. The axial position (longitudinal position) on the tablet 1-23.24H roller 12.13 is fixed, and for this purpose, for example, a stopper 25.25 as shown is installed at the bottom. Formerly located in Room $i, 11.

-, the upper 'frt'I' pole 26 is arranged approximately parallel to the earth orientation Buddha of the first part πi, h L t. ing. This upper 'it[j21j
It consists of a roof-shaped main electrode 27 extending in the longitudinal direction and an auxiliary electrode 28 fixed in the center of this main electrode 27, and a high frequency electric power source 29 is connected between the lower electrode 11 and the auxiliary electrode 28. There is. The protruding length of the auxiliary πfl128 in the T direction is changed in the length direction of the electrode, and a portion corresponding to the collision position of the tabl...
In other words) 1 has a shape in which the protruding length of the portion 28a corresponding to the central portion is the thickest when viewed as one tablet 23, 24'i, and gradually decreases toward both ends 28b, 28b.

According to the above configuration, the roller 12.1 is driven by the motor 22.
3 rotates the tablet) 23.24, and when high frequency power is applied between the sumo wrestler and the lower electrode 26.11, the upper electrode 26 and the lower electrode 11, and furthermore the upper electrode 26 and the tablet 23. An electric field is generated between the tablets 24 and 24, and due to the anti-frost heating, the tablets 23 and 24 are heated in the circumferential direction.

At this time, the auxiliary electrode 28 and the tablet 23.24
As for the electric field generated between the tablets 23 and 24, the electric field strength at the central portion 28a having a large protrusion length is greater than that at both end portions 28b, 28b. Also authored.

<It will be heated, and the center will be heated to a high temperature.

Therefore, the tablet 23.2 heated in this way
4 as one tablet and load it into the pot B of the transfer molding machine as shown in FIG.
As shown in the figure, the central portion is deformed first, and then both ends are deformed. For this reason, the air a existing on the inner surface of Po Soto 8 and the outer periphery of Soto 23 and 24 is expelled to the top and bottom of Po Soto 8 as shown by the arrows in the figure, thereby trapping the air within the resin. This can definitely be prevented. That is, it is possible to produce molded products with good appearance and no bubbles.

[Embodiment 2] FIG. 5 shows a second actual tlI example of the present invention, in which the upper cylinder, the pole 2
This is an example of a different version of 6A. Therefore, the first actual journey example 1
The same parts are given the same reference numerals and their explanation will be omitted. In this example, the upper electrode 26A is formed in a boat bottom shape, and
The amount of downward protrusion of the bottom edge 30 is varied in the entire length direction, and the portion corresponding to the combined central portion of the taplets 23 and 24 is made larger than the other portions (portions corresponding to both ends).

Therefore, according to this embodiment, the strength of the electric field generated between the upper electrode 26A and the lower electrode 11 already differs in the length direction, and the strength in the central part is greater than in other parts. As a result, tablet 23 as well as Maeshio 11
．． 24 is heated to a high temperature at both ends and in the center to completely prevent sealing and bubble formation in the transfer mold.

Embodiment FIG. 6 is a third real saturation series of the present invention, and the figure schematically shows the main part. In the figure, the lower electrode 31 is
Similarly, the rollers are composed of rollers, but in this case, the rollers are constructed by pairing a plurality of short rollers 32' made of a conductive material in series with an insulating material 33 interposed therebetween. On the other hand, the upper electrode 34 also has a conductive member 35 and an insulating member 36 correspondingly.
It has a structure in which the and are arranged alternately in series. Each row is composed of short rollers 33, conductive tubes, and members 35 located vertically opposite to each other at the upper and lower electrodes 34 and 31, and each row is formed between the short rollers 33 and the conductive members 35, which are arranged in a stiff manner. An independent high frequency power 37 is applied to obtain [4]. At this time, a high electric power 37a'Jk is applied between the short roller 33a and the conductive member 35a facing the combined central part of the tablets 23 and 24, and a low electric power 37a'Jk is applied to those facing both ends. configured to apply electrical power;

According to this configuration, the electric field strength at the center of the tablet 23, 24 is not greater than the electric field strength at both ends. , will be heated to high temperatures. It goes without saying that this can prevent air from being trapped in the transfer mold, thereby preventing air bubbles.

Incidentally, the partial electrode 31 can also be connected in common, and therefore, in this case, it may be configured as an integral roller.

〔effect〕

(1) Since the protrusion length of the auxiliary electrode of the upper electrode is maximized at the center, the electric field strength at the center of the tablet is the thickest, which allows the center of the tablet to be heated to a high temperature as well as both ends. .

(2) Since the upper N-pole itself is configured so that the amount of protrusion is maximum at the center, the electric field strength at the center of the tablet can be maximized in the same way, and the center of the tablet can be heated to a high temperature.

(3) At least the upper electrode is divided in the entire length direction and an electric field is applied independently to each part, and the electric field is maximized at the center of the tablet, so the upper electrode is divided at both ends of the central part of the tablet. Can be heated to higher temperatures than

(4) As mentioned in (1), (2), and (3) above, since the center and both ends of the tablet are also heated to high temperatures, air can be used effectively when compressing the insides of the transfer mold. This prevents air from being trapped in the resin and completely prevents air bubbles from forming in the molded product.

The invention made by the present inventor is described above in detail based on the actual implementation, but the present invention is not limited to the above-mentioned actual journey example, and various changes can be made without overcoming the gist of the invention. Needless to say. For example, when heating one or more tabs, the electric field strength distribution can be adjusted in accordance with the entire length of the tablet.

Also, according to Noriyoshi Dobe, the shape of the pole is shown as a shape other than II,
But that's fine.

[Application field]

In the above Komaaki, we have mainly explained the case where the invention made by the present inventor is applied to the preheating device for tablets of transfer molding equipment, which is the field of application that formed the background of the invention, but it is not limited to the application of the invention to the preheating device for tablets of transfer molding equipment. It can also be applied as a heating device for articles that require high temperature heating of the center of the article as well as the edges.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the device that was previously tested, Figure 2 is a sectional view of the pot that clarifies all the problems, and Figure 3 is the first practical example of the present invention. Figure 4 is a cross-sectional view of the sixth body to explain the effect, Figure 5 is a schematic diagram of the body of the second embodiment 1, and Figure 6 is a schematic diagram of the main parts of the third embodiment. FIG. 11 = lower electrode, 12, t aa-a, 23.
24...Tablet, 26.27A...Upper electrode,
27... Main electrode, 28... Auxiliary electrode, 29... High frequency power, 30... Bottom edge, 31... Lower electrode, 32
... short roller, 34 ... upper electrode, 35 ... conductive part cut, 37 ... high frequency power. Figure 1 Figure 4 Figure 2 Ox Figure 3 Figure p Figure 4

Claims (1)

[Scope of Claims] 1. The structure is such that high-frequency lightning can be fully supplied between a lower electrode on which an object to be heated is placed and an upper electrode disposed opposite thereto, and the object to be heated is The heating device is characterized in that the upper electrode is configured such that the electric field strength at the central portion in the longitudinal direction is greater than the electric field strength at both ends. 2. The heating device according to claim 1, wherein the upper electrode is provided with an auxiliary electrode, and the auxiliary electrode has a maximum protruding length toward the lower electrode at the center. 3. The heating device according to claim 1, wherein the bottom edge of the upper electrode is configured to protrude furthest toward the lower electrode at the center. 4. The heating device according to claim 1, wherein the upper electrode is divided in the length direction so that a large amount of force can be applied independently to each part, and the electric power of the part corresponding to the central part is set to the maximum. . ``5. The heating device according to any one of claims 1 to 4, wherein the object to be heated is a tablet for transfer molding.