JPS61106210A - High-frequency preheater - Google Patents

Abstract

PURPOSE:To simplify a driving mechanism and contrive quick and uniform heating by a method wherein insulating rollers, putting a material to be heated thereon and rotating the material, are arranged while a protrusion, approaching to the material to be heated, is formed on either one of upper and lower electrodes. CONSTITUTION:The rollers 3, 3, putting the material A to be heated thereon and rotating it, are constituted of insulating bodies made of material having small high-frequency loss while these rollers have no role of electrode. Accordingly, a space between the rollers can be wide enough and the material A to be heated can be heated stably even when the rotating speed thereof is increased whereby the driving mechanism becomes simple. The protrustions 1a, 2a are formed on at least one of upper electrode 1 or lower electrode 2 and whereby high-frequency energy may be concentrated on the material A to be heated and the quick and uniform heating may be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-frequency preheater for preheating thermosetting resin molding materials, ceramics, and various other materials to be heated.

As a conventional high-frequency preheater, as shown in the cross-sectional view of the main part in Fig. 5, the material to be heated ( A parallel electrode type high frequency preheater is known in which a high frequency voltage is applied between both electrodes using a high frequency oscillator (4). As the distribution of the heated material (A
) The temperature of each part inevitably became uneven.

In order to eliminate this drawback, the second roller electrodes (5), (5) are installed in parallel, as shown in the cross-sectional view of the main part in FIG. ') A roller electrode type high-frequency preheating machine that performs high-frequency preheating while rotating a tablet-shaped material to be heated (A) placed thereon is popular.

Problems to be Solved by the Invention However, in the roller electrode type high-frequency preheater, two roller electrodes (5) are required to uniformly heat the tablet-shaped material to be heated (A) to its center. ,(5
), but if the distance between the two roller electrodes (5), (5) is narrow like this, the center of gravity of the material to be heated (A) will become high, resulting in poor stability. , roller electrodes 8i (5), (5) must be supported and rotated while maintaining their insulation.
5), the structure of the drive mechanism attached to (:5) tends to be complicated.

The present invention has been made to solve these conventional problems.

Means for Solving the Problems The present invention provides a material with low high frequency loss on which the material to be heated (A) is placed and rotated in a high frequency preheater equipped with an upper electrode (1) and a lower electrode (2). Insulator roller made from (
3) and (3), and at least one of the upper electrode (1) and the lower electrode (2) is provided with the heated material (
Convex portions (1a) and (2d) approaching A)
A high frequency preheating machine characterized by forming.

By adopting such a configuration, the above-mentioned problems have been solved.

In the present invention, the rollers (3), (3) on which the material to be heated (A) is placed and rotated are made of an insulator made of a material with low high frequency loss, and these rollers have the role of electrodes. I won't let you accomplish it. Therefore, it is possible to make the distance between the rollers as wide as possible without causing the material to be heated (A) to fall, so even if the rotation speed is increased, the material to be heated (A)
) can be heated stably, and the roller drive mechanism is also simple.

Further, at least one of the upper electrode (1) and the lower electrode (2) has a convex portion (1a) close to the material to be heated (A).
1a) and (2d), high-frequency energy is concentrated on the material to be heated (A), and rapid and uniform heating thereof is achieved. In addition, the parts other than the convex parts (1a) and (2d) of the electrodes (1) and (2) are also
), so the convex part (1a)
, There is no risk of dielectric breakdown that could occur with (2d) alone.

The material of the insulating rollers (3), (3) is not particularly limited as long as it has insulating properties, and suitable materials such as plastics and ceramics can be used.

The protrusions (1a) and (2d) provided on at least one of the upper electrode (1) and the lower electrode (2) may be provided in -stripes or in several strips. Materials are copper, aluminum, brass,
Any conventional electrode construction material may be used, including stainless steel. The protrusions (1a), (2d) can be installed on the upper electrode (1) or the lower electrode (2) by cutting the electrode, but it is also possible to install the protrusions (1a), (2d) on the upper electrode (1) or the lower electrode (2) by cutting the electrode. It is advantageous to adopt a method of fixing an auxiliary electrode in an appropriate shape, such as a box shape, by any fixing means such as screwing, welding, or adhesive.

Example Next, embodiments of the present invention will be described based on the drawings.

1 to 4 are cross-sectional views showing the main parts of the high-frequency preheater of the present invention.

In both figures, (1) is the upper electrode and (2) is the lower electrode. Usually, the upper electrode (1) is placed on the hood side (not shown), and the lower electrode (2) is placed on the base side (not shown). Installed. (4) is a high frequency oscillator, and (A) is a tablet-shaped material to be heated.

(3), (3) are the upper electrode (1) and the lower electrode (
2) is a pair of insulating rollers arranged horizontally in two jug rows at an appropriate position between the .

The insulating rollers (3), (3) are made of a material with low high frequency loss, such as a fluororesin molded product, and play the role of placing and rotating the tablet-shaped material to be heated (A). The distance between the insulator rollers (3), (3) is
The distance between the roller electrodes (5), (5) in the conventional roller electrode type high frequency preheater as shown in FIG. 6 can be made wider.

(1a) and (2d) are convex parts installed on the upper electrode (1) or the lower electrode (2), and the heated material placed on the insulating rollers (3) and (3). (A)
It plays the role of applying high-density high-frequency energy by bringing electrodes close to each other in a limited area.

Figure 1 shows the case where the convex part (2d) is installed on the lower electrode (2), Figure 2 shows the case where the convex part (1a) is installed on the upper electrode (1), and Figure 3 shows the case where the convex part (1a) is installed on the upper electrode (1). ), and a protrusion (2d) is also provided on the lower electrode (2), FIG. 4 shows that a plurality of protrusions (2
d) This shows the case where... is installed.

Function In the high frequency preheater of the present invention shown in Figs. 1 to 4, the distance between the insulating rollers (3), (3) is sufficiently wide to stably support the material to be heated (A), Next, the rotation of the insulator rollers (3) and (3) is started, and at the same time a high frequency voltage is applied between the upper mold & (1) and the lower electrode (2) by the high frequency oscillator (4). A high-frequency electric field distribution occurs as shown by the dotted line, and the distribution is at the convex portion (1a) %
The material to be heated (A) becomes highly dense at (2d).
heating is done quickly and uniformly.

Effects of the Invention In the present invention, insulating rollers (3), (3
) only plays the role of rotating the material to be heated (A), so the distance between these insulating rollers (3), (3) can be made wider than the distance between conventional roller electrodes. Therefore, the centering of the material to be heated (A) is lowered and the stability is increased, so even if the rotational speed of the roller is increased, the material to be heated (A) is
) can be stably heated, so the material to be heated (
Not only can the dropping error in A) be prevented, but also uniform heating can be achieved.

In addition, the insulating rollers (3), (, 3) of the present invention do not need to be supported and rotated while maintaining the insulation of the roller electrodes, unlike conventional roller electrode type high-frequency preheaters. The mechanism becomes simple.

Further, at least one of the upper electrode (1) and the lower electrode (2) is provided with a convex portion (1) so as to approach the material to be heated (A).
Since a) and (2d) are formed, high frequency energy is concentrated on the material to be heated (A), and rapid and uniform heating thereof is achieved. In addition, the convex portions of the electrodes (1) and (2) (
Locations other than 1a) and (2d) are also heated material (A)
Since high frequency energy is given to the convex portion (1a),
There is no risk of dielectric breakdown that could occur with (2d) alone.

Therefore, the high frequency preheater of the present invention has great industrial significance.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing the main parts of the high-frequency preheater of the present invention. Figures 5 and 6 are cross-sectional views showing the main parts of conventional high-frequency preheaters, where Figure 5 shows a parallel electrode type high-frequency preheater and Figure 6 shows a roller electrode type high-frequency preheater. It is. (1)... Upper electrode, (2)... Lower electrode, (1a
). (2d)...Protrusion, (3)...Insulator roller, (4
)...High frequency oscillator, (5)...Roller electrode, (A
)・・・Material to be heated

Claims (1)

[Claims] 1. In a high frequency preheater equipped with an upper electrode (1) and a lower electrode (2), an insulating roller (3) made of a material with low high frequency loss on which the material to be heated (A) is placed and rotated; (3), and convex portions (1a) and (2d) are formed on at least one of the upper electrode (1) and the lower electrode (2) so as to be close to the heated material (A). A high frequency preheating machine characterized by: