JPS62259384A - Hot plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a hot plate used in a hot press IB etc.
In particular, the present invention relates to an improvement in a hot plate whose heat source is a sheathed heater in which a heater element is disposed within a longitudinally tubular sheath.

(Prior art and its problems) A hot plate is a plate having a heatable structure, and is used in a press machine or the like to heat a workpiece.

For example, a hot press machine is used to integrate laminates made by overlapping laminate materials such as resin-impregnated sheets, resin films or sheets, metal foils, slopes, etc. to produce laminate molded products such as electrical printed wiring boards and temporary laminates. , a plurality of hot plates are arranged between the fixed plate and the movable plate so that the laminated material (workpiece) can be heated by these hot plates, and the By heating the laminate with a heating plate and applying pressure based on the pressure between the fixed platen and the movable platen, the laminate can be integrated to produce the desired laminate molded product. It has become.

By the way, one type of such 2-Yasaka is a sheathed heater (cartline heater) in which a heater element that generates heat by passing through 1E is disposed inside a longitudinal tubular sheath, which is formed in a hot plate. There is a type of heat plate that is placed in a predetermined heater insertion hole and used as a heat source, but conventionally, in a hot plate that uses such a sheathed heater as a heat source, the sheathed heater has only one heater element inside. Because of this structure, it was difficult to accurately control the hot plate to the desired temperature distribution, and in particular, it was difficult to heat the hot plate uniformly over its entire effective area. Ta.

For example, in the above-mentioned hot press apparatus, in order to improve the quality of the product, it is desirable to uniformly heat the hot plate to a predetermined target heating temperature over the entire effective area of the hot press. Simply electrically controlling each sheathed heater (heater element) placed in the insertion hole in the same way will result in differences in heat radiation conditions and heat transfer conditions depending on each part of the heat plate, and differences in the heater element's longitudinal direction of the sheathed heater. It is inevitable that variations in the temperature (surface temperature) of the hot plate will occur due to variations in capacity or non-uniformity in the state of contact between the sheathed heater and the hot plate. Therefore, the effective surface of the hot plate is usually divided into a plurality of zones, and the sheathed heaters corresponding to each zone are energized independently of each other. If the effective surface of the hot plate is divided into multiple zones and each zone is heated independently to the target heating temperature,
Heat (Since the variation in temperature within each zone is smaller than the variation in temperature as a whole, the temperature of the entire heating plate can be controlled more easily than when the sheathed heaters on the entire heating plate are energized in the same way.) 1- can be made small, and therefore the temperature of the heat dividing plate can be made uniform by making the variation 1- small.

However, in the conventional heating plate, as mentioned above, only one heater element is arranged in the sheathed heater, so in the arrangement direction of the sheathed heater, the heating plate can be heated independently of each other. Although it can be divided into a large number of controllable zones, in the longitudinal direction of the sheathed heater, the hot plate cannot be divided into such 1'J1 zones; Inserting and arranging the sheathed heater into the heater insertion hole from two directions, it was difficult to divide the hot plate into two zones, so by controlling the temperature of the hot plate separately, There were limits to achieving uniform temperature.

On the other hand, in parallel with such divisional control of the hot plate, the heater capacity of the heater element is adjusted in advance in the longitudinal direction of the sheathed heater so that the hot plate temperature in the longitudinal direction of the sheathed heater is uniform at the target heating temperature. However, in this case, it is necessary to use a sheathed heater with a heater capacity adjusted according to the target heating temperature each time the target heating temperature differs. There is a problem that the heater has to be replaced.

(Solution Means) Here, the present invention was made against the background of the above-mentioned circumstances, and its feature is that a plurality of heater elements are arranged independently in the longitudinal direction within a longitudinal tubular sheath. The multi-circuit sheathed heaters arranged in series are respectively arranged in predetermined heater insertion holes formed in the hot plate, and each heater element of the multi-circuit sheathed heater covers the hot plate portion. The reason is that each can be heated.

(Function/Effect) According to such a hot plate, in the arrangement direction of the sheathed heater (multi-circuit sheathed heater), the hot plate can be divided into many zones whose temperature can be controlled independently from each other, just like the conventional hot plate. Not only can it be divided, but also in the longitudinal direction of the sheathed heater it is possible to divide the hot plate into a large number of zones whose temperature can be controlled independently of each other. In other words, according to the hot plate according to the present invention, the effective surface of the hot plate is divided into a plurality of zones.
The effective surface of the sheathed heater can be divided more finely in the longitudinal direction of the sheathed heater than a conventional heating plate. Therefore, by independently controlling the temperature of each of the divided zones, the heating plate It becomes possible to control the temperature distribution state of 41' more precisely,
Even when heating a hot plate to a uniform temperature, it is possible to make the 1 m degree more uniform than with conventional methods.

In addition, in this way, the hot plate can be divided into a plurality of zones whose temperature can be controlled independently of each other in the longitudinal direction of the sheathed heater, and the temperature of the hot plate can also be divided and controlled in the longitudinal direction of the sheathed heater. Because of this, it is no longer necessary to adjust the heater capacity of the heater element in advance according to the target heating temperature, unlike with conventional heating plates, and therefore it is no longer necessary to adjust the heater capacity of the heater element in advance according to the target heating temperature. It is no longer necessary to replace the sheathed heater. Also, for the same reason, the temperature increase of the hot plate: 01? It is now possible to accurately control the temperature distribution state of the hot plate even during wholesale, which is advantageous when it is necessary to adjust the temperature distribution state of the hot plate during 7-temperature control of the hot plate. It was.

Moreover, according to the heating plate according to the present invention, the heating plate can be divided into a plurality of zones in the longitudinal direction of the sheathed heater by simply arranging one sheathed heater in one heater insertion tag. Another advantage is that the lead wires for energizing each heater element can be drawn out from the same direction of the hot plate. If the glue wires for energizing each heater element of the sheathed heater are pulled out from the same direction of the hot plate, it will be easier to attach the sheathed heater to the hot plate, and the lead wire routing and wiring work will be easier. It becomes.

In addition, in the case of a hot press device, loading objects and unloading molded products from the side opposite to the direction in which the lead wires are pulled out makes loading and unloading operations easier. This also improves safety.

Incidentally, in the conventional heat plate in which the heat plate is divided into two zones in the longitudinal direction of the sheathed heater, two zones are divided by arranging the two sheathed heaters in series in the heater insertion hole, as described above. Because of this, the lead wires for energizing each heater element could not be pulled out from the same direction of the hot plate, and therefore the sheathed heaters could not be attached to the hot plate or the lead wires could not be pulled out from the same direction. The routing and wiring operations were troublesome.

(Example) Hereinafter, in order to clarify the present invention more specifically,
One embodiment thereof will be described in detail based on the drawings.

First, No. 1121 shows an example of a dot press device equipped with a hot plate according to the present invention, in which lO is a fixed plate, and at its four corners, Hose 1
The stay 14 is fixed and supported by the upper end of the stay 14 erected on the top of the stay 14 . Further, reference numeral 16 denotes a movable platen, which is fixed to a ram 20 of a cylinder 18 provided below the heath 12, and can be moved up and down as the ram 20 expands and contracts. As is well known, a plurality of hot plates 22 are arranged in multiple stages between the fixed platen 10 and the movable platen 16, and a workpiece such as a laminate is inserted between the hot plates 22. 24 is pressed and pressed by the hot plates 22, and is pressurized by the clamping action of the fixed platen 10 and the movable platen 16.

By the way, each hot plate 22 has a rectangular planar shape, as shown in FIG.
2 in parallel to the plate surface (6 in this case)
The heater insertion holes 25 are formed at approximately equal intervals. The sheathed heater 2 is inserted into each of the heater insertion holes 25 from the same direction and serves as a multi-circuit sheathed heater.
6 is placed.

These sheathed heaters 26 have heater elements 30 (30A, 30B, 30C) of the same shape inside a longitudinal tubular sheath 28 with one end closed, as shown in No. 3M.
are arranged in series, and lead wires 3 are individually connected to one end of each heater element 3o.
2 (32A, 32B, 32C) and a cast lead wire 34 which is in common contact with the other end of these heater elements 30, extends from the opening of the sheath 28, and the lead wire 32 By applying a voltage between each of the heater elements 3o and the common glue wire 34, these heater elements 3o can be selectively heated by IJrI. In this embodiment, as mentioned above,
These sheathed heaters 26 are connected to each heater insertion hole 2 of the hot plate 22.
5 from the same direction, and each of the hot plates 22 on which the sheathed heaters 26 are placed faces the same direction with respect to the Hontopress device, and the sheathed heaters 26 Lead wire 3 pulled out
2.34 are routed and wired on the side of the apparatus opposite to the direction of incision into the workpiece 24 (direction of discharging the molded product).

Note that the heater element 30 of the sheathed heater 26 is usually wound around a predetermined ceramic core, and the sheathed heater 26 is wound around a predetermined ceramic core.
The ceramic core is fixed to the outer surface of the ceramic core by a heat-resistant insulating material filled between the ceramic core and the inner surface of the ceramic core. Further, each of the lead wires 32 and 34 is disposed so as to penetrate through the ceramic core, and to be integrally embedded in the ceramic core with yellow edges at appropriate intervals from each other. becomes.

Further, in this embodiment, in such a hot press apparatus, the heater element 30 of the sheathed heater 26 disposed on each hot plate 22 is energized by a control circuit as shown in FIG. , as shown in FIG. 2, the effective surface (here, the entire surface) of the hot plate 22
Heating is controlled independently for each of the zones 1 to 2, which are divided into nine sections.

That is, in FIG. 4, 36 is a temperature controller with a PID control function provided corresponding to each divided zone of the hot plate 22, and a corresponding semiconductor non-contact relay (hereinafter referred to as SS relay). ) 38, and each corresponding SS relay 38 is turned on according to a preset program based on the temperature signal from the thermocouple 40 (see Figure 2) arranged in each corresponding zone.・It is designed to be OFF controlled. As a result, each corresponding heater element 30 (here, two heater elements) 30, 3 is connected to a power source (not shown).
0), each corresponding zone is heated at a preset heating rate, and the temperature of each corresponding zone is set to the target temperature. A After the temperature rises to
The temperature of each corresponding zone is maintained at its target heating temperature.

Each temperature controller 36 also has a 1ff
A program setting device 41 and a temperature setting device 42 are connected to each other, so that the program for each temperature controller 36 can be set alternatively by the program setting device 41, and the temperature setting device 42, the target heating temperature is set to tA, so that the programs set in each temperature controller 36 corresponding to the target heating temperature are simultaneously translated.

Note that between each SS relay 38 and the power source, a plurality of (here, two) variable resistors 42 are connected by a relay circuit (not shown) to be selectively selected depending on the temperature of the corresponding zone.
(42Δ, 42B) are arranged, and when the temperature of the heating plate 22 is controlled and the temperature in the corresponding zone reaches a predetermined temperature lower than the target heating temperature, the variable resistor 42 can be switched from one with a smaller resistance value (42A) to one with a larger resistance value (42B). As a result, the temperature increase rate of each zone during the heat + Fi 22 temperature increase control is gradually decelerated, and the final temperature of each divided zone, and by extension the overall temperature of the hot plate 22, is The heating temperature is set to rise as quickly as possible and stabilized with good accuracy.

According to such a hot press device, as described above, each heat (22) is divided into three in the arrangement direction of the sheathed heaters 26 and in the longitudinal direction thereof, and divided into nine zones ■ to ■ in a mesh pattern. Since the temperature in each zone is independently controlled and raised to the same target heating temperature, there may be differences in the heat dissipation state or heat transfer state in each part of the heat plate 22 or the sheathed heater 26. The hot plate 22 due to non-uniformity of the contact state with the hot plate 22, etc.
It is possible to reduce variations in temperature as much as possible to make the temperature of the entire hot plate 22 as uniform as possible, and furthermore, it is possible to make the temperature of the whole hot plate 22 as uniform as possible.
Variations in temperature between the two can also be made as uniform as possible. In this embodiment, as described above, each hot plate 22 is divided into three parts not only in the arrangement direction of the sheathed heaters 26 but also in the longitudinal direction thereof. Compared to conventional heat plates that are divided, the temperature of the heat plate 22 can be more evenly adjusted to the target heating temperature.
Therefore, it is possible to produce molded products (laminate molded products) of even higher quality than before.

Further, in this way, the hot plate 22 is divided into three zones in the longitudinal direction of the sheathed heater 26, and the temperature of the hot plate 22 can be made more uniform in the longitudinal direction of the sheathed heater 26 than in the past. Therefore, each heater element 3 of the sheathed heater 26 is
Target addition of heater capacity of 0? It is no longer particularly necessary to make adjustments in advance according to the 1A degree, and therefore there is no longer a need to replace the sheathed heater 26 every time the target heating temperature changes. Also, for the same reason, the temperature increase of the hot plate 22 is controlled if! Even at 1 o'clock, it has become possible to control the temperature distribution state of heat 1 to 22 with good accumulation, so even when controlling the temperature increase of the hot plate 22,
This makes it possible to make the temperature as uniform as possible and improve product quality.

Furthermore, as described above, since the lead wires 30 and 32 for energizing the heater elements 30 of each sheathed heater 26 are drawn out to the same side of the hot press device, the hot plate of the sheathed heater 26 This has the advantage that the operation for attaching the wires 32 and 22 is simple, and the routing and wiring work of the lead wires 32 and 34 is also simple. In addition, since the lead wires 32 and 34 are drawn out and wired on the opposite side to the direction in which the workpiece 24 is carried in, the workpiece 24 is
Another advantage is that loading (loading) the product between the hot plates 22 of &24 and unloading the product can be carried out easily and safely.

Although one embodiment of the present invention has been described above, this is a literal illustration, and it goes without saying that this discussion should not be interpreted as being limited to this specific example.

For example, in the embodiment described above, three heater elements 30 are provided for each sheathed heater 26, and the hot plate 22
is divided into three in the longitudinal direction of the sheathed heater 22, but the number of heater elements 30 and the corresponding number of divisions of the hot plate 22 in the longitudinal direction of the sheathed heater 26 are not necessarily limited to this. Not a thing, but a fifth
As shown in the figure, only two heater elements 22 are disposed in each sheathed heater 26, and the sheathed heater 2
The hot plate 22 may be divided into two in the longitudinal direction of the heat plate 6, or four or more may be provided and the heat plate 22 may be divided according to the number of the heat plates. Note that the larger the number of heater elements 30 disposed in the sheathed heater 26, the more accurately the temperature distribution state of each hot plate 22 can be determined.
However, the number of lead wires that can be drawn out from each sheathed heater 26 depends on the dimensions of the sheathed heater, the voltage applied between each lead wire, or the number of lead wires that can be drawn out from each sheathed heater 26. 22 Conditions of Use (Environmental Conditions)
The number of heater elements 30 is usually selected depending on these conditions.

Further, in the embodiment, each heater element 30Δ, 30B is arranged within the sheathed heater 26.

One end of 30C is connected to a common lead wire 34, and the other ends are connected to separate lead wires 32A, 32, respectively.
B, 32C, and by applying a voltage between the lead cotton 34 and each corresponding lead wire 32, the energization of the heater elements 30 was controlled independently, but as shown in FIG. In some situations, the other ends of two of them may be connected to a common lead wire 32D to connect any two heater elements, as shown in FIGS. It is also possible to control the energization of all three heater elements 30 at the same time, and furthermore, as shown in FIG.
3OA, 30B, 30C) with common lead cotton 34
It is also possible to simultaneously control the energization through 321E and 321E. In such a case, the other ends of any two or three heater elements 30 may be connected inside the sheathed heater 26.
Alternatively, it is possible to connect it outside the sheathed heater 26, but in order to reduce the number of lead wires drawn out from the sheathed heater 26, it is desirable to connect it inside the sheathed heater 26, which increases the freedom of design. From this point of view, it is desirable to connect externally. Further, the number of connections B of each heater element 30 increases as the number of heater elements 30 disposed in the sheathed heater 26 increases.

Further, in the embodiment, each end of each heater element 30 disposed in the sheathed heater 26 is connected to a common lead cotton 3.
However, the present invention is not limited to this, and it is also possible to draw out the lead wires for energizing each heater element 30 separately. However, in this case, since the number of lead wires per number of heater elements 30 increases, the number of heater elements 30 that can be arranged in the sheathed heater 26 increases compared to the case of the above embodiment. f&il will be limited accordingly. In the hot press apparatus, the workpiece 24 may be processed with the entire hot press apparatus housed in a vacuum box, so it is desirable that the lead wires be placed apart from each other to an extent that does not cause vacuum discharge. Therefore, in such a case, as the number of lead wires arranged per heater element 30 increases, it is inevitable that the number of heater elements 30 that can be arranged in the sheathed heater 26 decreases. It is.

Further, in the above embodiment, a thermocouple 40 and a temperature controller 36 were provided for each divided zone of the hot plate 22, but as shown in FIG. 40 and the temperature controller 36 can also be provided in common to the heater elements 30 of a plurality of zones.

Furthermore, as shown in FIG. 11, the temperature controller 36 can be provided commonly to the heater elements 30 of each divided zone. That is, the 11th
In the figure, the temperature controller 36 is the manual selection circuit 4.
6 to the thermocouple 40 disposed in each divided zone, and the predetermined circumference! The temperature signals of each thermocouple 40 are sequentially taken in at the field. Then, in synchronization with the switching cycle of the thermocouples 40, a control signal (analog signal) for each corresponding zone is output, and this is sent to the converter 48.
It is designed to be supplied to Further, the control signal is converted into an ON/OFF signal by the converter 48, and is supplied to each corresponding SS relay 38 through an output selection circuit 50. Then, as in the embodiment described above, the heater elements 30 disposed in each corresponding zone are energized and controlled by the SS relay 38.
The temperature of each zone can be controlled.

Note that a program setting device 41 is connected to the temperature controller 36 in the same manner as in the embodiment described above, and the heating program corresponding to each zone can be individually set by this program setting device 41, and the heating program corresponding to each zone can be individually set. A temperature setting device 42 similar to the example is connected, and this temperature setting device 4
2, each time the target heating temperature is set to OFF, the temperature controller 36 selects a heating program for each zone set according to the target heating temperature. In addition, each SS from the output selection circuit 50
When the target heating temperature is maintained, the signal supplied to the relay 38 is controlled ON-OFF during the scanning cycle of the thermocouple 40 according to the comparison result between the set temperature and the actually measured temperature.

Furthermore, here, as shown in the figure, each SS relay 38 is provided with three variable resistors 44 (44,'
44B, 44G) are connected in parallel with each other, and by selectively selecting these variable resistors 44, the temperature increase rate of each zone can be reduced in three stages.

In addition, in the above embodiment, an example was described in which the present invention was applied to a hot plate of a true breath device, but the present invention is not limited to this, and can also be applied to an injection molding machine, etc. Is possible.

In addition, although not listed, various modifications may be made without departing from the spirit of the present invention.

It goes without saying that the present invention can be implemented with modifications, improvements, etc.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of a hot plate apparatus according to the present invention, and the second part is a plan view schematically showing the hot plate shown in FIG. Fig. 3 is a schematic cross-sectional view for explaining a sheathed heater used in the hot plate shown in Fig. 2. Fig. 4 is a circuit diagram showing an example of a heating control circuit for the hot plate shown in Fig. 2. 5 is a diagram corresponding to FIG. 3 showing a sheathed heater in another embodiment of the present invention. FIG. 10 is a circuit diagram showing a different connection mode from that shown in FIG. 3 of the sheathed heater arranged. FIG. 10 and FIG. It is a circuit diagram showing an example. IO: Fixed platen 16; Movable device 22: Temperature 25: Heater insertion hole 26: Sheathed heater (multi-circuit sheathed heater) 30 (30A, 30
B, 30C): Heater element 32 (32A, 32B, 32C, 32D. 32E), 34: Lead wire 36: Temperature controller 38 Two-semiconductor non-contact relay 40: Thermocouple 41 Nibrogram setting device 42: Temperature setting device

Claims (2)

[Claims] (1) A multi-circuit sheathed heater consisting of a plurality of heater elements arranged independently and in series in the longitudinal direction within a longitudinally tubular sheath is inserted into a predetermined heater insertion hole formed in a hot plate. A hot plate characterized in that the hot plate parts are respectively arranged so that each of the hot plate parts can be heated by each heater element of the multi-circuit sheathed heater. (2) The plurality of heater elements are energized and controlled by at least two independent circuits, so that the heating control of the heater element disposed portion of the hot plate can be performed independently. The hot plate mentioned.