JP2011156739A - Apparatus for preheating of casting material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly raise a resin temperature of an epoxy resin in a resin tank to a prescribed temperature in a short time. <P>SOLUTION: A preheating apparatus includes: the resin tank 1 in which a casting material 2 such as an epoxy resin is filled; a heater 3 inserted in the casting material 2 and preheating the material 2; a vertically movable device 7 for vertically moving the heater 3 between an upper surface and a bottom surface of the casting material 2; a temperature sensor 11 for measuring the resin temperature of the casting material 2; and a tank mounting base comprising a rotary base 12 for mounting the resin tank 1 and a vibrating base 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a preheating device for a casting material such as an epoxy resin, and more particularly to a preheating device for a casting material that preheats a resin temperature in a short time.

  Conventionally, when pouring a casting material into a casting mold, it is known to preheat the casting material to a predetermined temperature and reduce the viscosity in order to improve quality and workability. The casting material is preheated by winding a band heater around the outer periphery of the resin tank in which the epoxy resin main agent and the curing agent are mixed, and increasing the temperature to, for example, a predetermined temperature of 60 to 80 ° C. while detecting the resin temperature ( For example, see Patent Document 1.)

JP 2005-81560 A (Page 4, FIG. 1)

The conventional casting material preheating apparatus has the following problems.
When preheating is performed by wrapping a band heater around the outer periphery of the resin tank, since heating is performed from the outside, it takes a long time of several to several tens of hours to raise the resin temperature to a predetermined temperature, and the lead time is long. Casting work has been difficult.

  On the other hand, there is a method in which the resin tank is carried into a heating furnace and preheated, but in order to raise the resin temperature to a predetermined temperature, a long time is required as described above. In addition, it is necessary to secure a space for installing the heating furnace. Further, the resin temperature is different between the hot air outlet side in the heating furnace and the opposite side, and the resin temperature becomes uneven. It was easy.

  In addition, when a difference in resin temperature occurs between the upper and lower sides and the left and right in the resin tank, the viscosity is different and the filling amount per unit time into the casting mold becomes discontinuous. Further, the flow of the resin in the casting mold becomes non-uniform, and uniform heat curing cannot be performed, making it difficult to ensure the mechanical and electrical characteristics of the cast product.

  The present invention has been made to solve the above-described problem, and provides a casting material preheating device that facilitates casting work by uniformly raising the resin temperature in a resin tank to a predetermined temperature in a short time. With the goal.

  To achieve the above object, a casting material preheating apparatus of the present invention includes a resin tank filled with a casting material, a heater inserted into the casting material and preheating the casting material, The apparatus includes a vertically movable device that moves the heater up and down, a temperature sensor that measures a resin temperature of the casting material, and a tank mounting base on which the resin tank is mounted.

  According to the present invention, the heater is inserted directly into the resin tank and the casting material is preheated while moving the heater, so that the resin temperature can be uniformly raised to a predetermined temperature in a short time, Casting work can be facilitated.

The side view which shows the structure of the preheating apparatus of the casting material which concerns on Example 1 of this invention. AA sectional drawing of FIG. The figure explaining the temperature characteristic of the preheating apparatus of the casting material which concerns on Example 1 of this invention. The top view which shows the heater of the preheating apparatus of the casting material which concerns on Example 2 of this invention. Sectional drawing which shows the heater of the preheating apparatus of the casting material which concerns on Example 3 of this invention.

  The present invention is to insert a heater directly into a resin tank filled with a casting material, move the heater at least up and down, and raise the resin temperature to a predetermined temperature. Embodiments of the present invention will be described below with reference to the drawings.

  First, a casting material preheating apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing the configuration of a casting material preheating device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is according to the first embodiment of the present invention. It is a figure explaining the temperature characteristic of the preheating apparatus of casting material.

  As shown in FIG. 1, a bottomed cylindrical resin tank 1 is filled with a casting material 2 such as a liquid epoxy resin, and a heater 3 is directly inserted into the casting material 2. . The heater 3 is provided in a metal tube such as stainless steel, and this metal tube is fixed to one end of the heater fixing rod 4. The other end of the heater fixing rod 4 is led out of the resin tank 1 and is fixed to a rotating device 5 having a built-in motor for rotating the heater fixing rod 4 in a rotatable manner. The rotating device 5 is fixed to a vertically movable device 7 constituted by a hydraulic lifter or the like that moves the heater fixing rod 4 movably in the vertical direction by a support plate 6. The vertically movable device 7 is attached to a fixed base 8.

  The heater 3 is provided with a first temperature sensor 9 that measures its own temperature. A support plate 10 is fixed in the casting material 2 in the middle portion of the heater fixing rod 4 and a second temperature sensor 11 for measuring the resin temperature is attached. The second temperature sensor 11 can adjust the height and position according to the filling amount of the casting material 2.

  The resin tank 1 is placed on a rotatable rotating pedestal 12 having a built-in motor and the like, and the rotating pedestal 12 is placed and connected to a vibration cradle 13 that generates fine vibrations in the vertical direction.

  Operation control of the rotating device 5, the vertically movable device 7, the rotating gantry 12, and the vibration gantry 13 is performed by a control device 14 attached to the fixed gantry 8. In addition, temperature measurement by the first temperature sensor 9 and the second temperature sensor 11 and operation control of the heater 3 are also performed by the control device 14. In addition, the lid | cover 15 is attached to the resin tank 1 for dust prevention and heat retention as needed.

  Here, as shown in FIG. 2, the heater 3 has a spiral shape whose center is fixed to the heater fixing rod 4 and spreads in the radial direction. Then, assuming that the cross-sectional area of the heater 3 when the inside of the resin tank 1 is viewed from the direction orthogonal to the axial direction is S1, and the cross-sectional area of the casting material 2 is S2, S1 ≧ S2.

  Next, a method for preheating the casting material 2 will be described. First, the casting material 2 is filled in the resin tank 1, and the heater 3 and the second temperature sensor 11 are inserted into the casting material 2. Next, while operating and controlling the heater 3 by the control device 14, the vertical movable device 7 is moved in the vertical direction, and the heater 3 is moved from the top surface to the bottom surface of the casting material 2. The moving speed is, for example, 10 cm / min, and the vertical movement is repeated several times. When the resin temperature reaches a predetermined temperature, the movement is stopped, and when the temperature is lowered, the movement is resumed, so that the resin temperature can be kept constant within a predetermined range.

  For example, when the resin temperature is set to 70 ° C., ON / OFF control of 68 ° C. and 72 ° C. is performed while controlling the temperature of the heater 3 with a signal from the first temperature sensor 9. Then, the resin temperature measured by the second temperature sensor has a temperature-time characteristic as shown by a solid line in FIG. That is, the resin temperature is linked to the temperature of the heater 3 and rises slightly above 70 ° C. when turned on, slightly falls when turned off, and with a resin amount of about 30 liters, a predetermined temperature is reached at a time t1 of several tens of minutes. Reaches 70 ° C.

  This is because the ratio of the cross-sectional area S1 of the heater 3 to the cross-sectional area S2 of the casting material 2 is S1 ≧ S2, so that the casting material 2 can be heated without a large temperature drop of the heater 3. It is. In general, the casting material 2 is stored at room temperature and preheated immediately before casting, but since the cross-sectional area of the heater 3 is equal to or larger than that of the casting material 2, a sufficient amount of heat is supplied. It will be a thing. When there is a margin in the time t1 until the predetermined temperature is reached, S2 may be made larger than S1. In practice, the temperature rise depends on the surface area of the heater 3, but here it is simply shown in cross-sectional area.

  In the conventional method in which a heater is wound around the outer periphery of the resin tank 1, the temperature reaches a predetermined temperature of 70 ° C. at a time t2 of several hours as shown by a one-dot chain line in FIG. The greater the amount of resin, the greater the difference between times t1 and t2. If a plurality of first temperature sensors 9 and second temperature sensors 11 are provided, fine temperature control can be performed.

  Here, by operating the rotating device 5 and rotating the heater 3 at, for example, 50 rpm, the time t1 can be further shortened. In addition, the time t1 can be shortened by rotating the rotating mount 12. That is, by rotating the heater 3 and the resin tank 1 relatively, the time t1 for the resin temperature to reach a predetermined temperature can be shortened. When the resin temperature reaches a predetermined temperature, the rotation is stopped, and when the temperature is lowered, the rotation is restarted, whereby the resin temperature can be kept constant within a predetermined range.

  Further, by operating the vibration device 13, the filler settled on the bottom surface of the resin tank 1 can be moved in the top surface direction, and the casting material 2 can be mixed more uniformly. If the vibration device 13 is operated immediately before the resin temperature rises to a predetermined temperature, the mixing efficiency can be improved. The rotating gantry 12 and the vibration gantry 13 are referred to as a tank mounting gantry.

  Here, the casting material 2 to be preheated in the resin tank 1 may be a mixture of an epoxy resin main component and a curing agent immediately before being poured into the casting mold, or may be a main component or a curing agent alone. Good. The single main agent and curing agent are mixed immediately before injection.

  According to the casting material preheating apparatus of the first embodiment, the spiral heater 3 having a large surface area is directly inserted into the resin tank 1 filled with the casting material 2 and moved at least up and down. Therefore, the resin temperature can be uniformly raised to a predetermined temperature in a short time, and the casting operation can be facilitated. In addition, the casting material 2 preheated in this manner makes the viscosity uniform and improves the mechanical and electrical characteristics of the cast product.

  Next, a casting material preheating apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a top view showing a heater of a casting material preheating apparatus according to a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is the shape of the heater. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the heater 16 has a radial shape with a plurality of heaters extending in the radial direction with the heater fixing rod 4 as the center. When the sectional area of all the heaters 16 when viewed from the direction orthogonal to the axial direction is S1, and the sectional area of the casting material 2 is S2, S1 ≧ S2.

  According to the casting material preheating apparatus of the second embodiment, in addition to the same effects as in the first embodiment, the casting material 2 can be easily stirred by the rotation of the heater 16, and the resin temperature is increased in a shorter time. Can be made.

  Next, a casting material preheating apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view showing a heater of a casting material preheating apparatus according to Embodiment 3 of the present invention. The third embodiment differs from the first embodiment in that a fluororesin film is provided on the heater. In FIG. 5, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, a coating film 17 made of fluororesin and having a thickness of several tens of μm is provided on the outer periphery of the heater 3 and the outer periphery of the heater fixing rod 4.

  According to the casting material preheating device of the third embodiment, the casting material 2 can be prevented from adhering to the heater 3 and the like in addition to the same effects as the first embodiment.

DESCRIPTION OF SYMBOLS 1 Resin tank 2 Casting material 3, 16 Heater 4 Heater fixing rod 5 Rotating device 6 Support plate 7 Vertical movable device 8 Fixed mount 9 First temperature sensor 10 Support plate 11 Second temperature sensor 12 Rotating mount 13 Exciting mount 14 Control device 15 Lid 17 Coating

Claims (7)

A resin tank filled with casting material;
A heater that is inserted into the casting material and preheats the casting material;
A vertically movable device for vertically moving the heater;
A temperature sensor for measuring the resin temperature of the casting material;
A casting material preheating apparatus comprising: a tank mounting base for mounting the resin tank.   2. The casting material preheating apparatus according to claim 1, wherein the heater and the tank mounting base are relatively rotated.   The casting material preheating device according to claim 1 or 2, wherein a vibration device is provided on the tank mounting base.   The casting material preheating apparatus according to any one of claims 1 to 3, wherein the heater has a spiral shape.   The casting material preheating apparatus according to any one of claims 1 to 3, wherein the heater is radial.   2. When the resin tank is viewed from a direction orthogonal to the axial direction, the cross-sectional area of the heater is S1, and the cross-sectional area of the casting material is S2, S1 ≧ S2. The casting material preheating device according to any one of claims 5 to 5.   The casting material preheating apparatus according to any one of claims 1 to 6, wherein a fluororesin coating is provided on a surface of the heater.

Images