JPS6320126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric heat insulator suitable for keeping food warm.

Conventional structure and its problems In general, this type of electric heat insulator heats a hot plate with a heater having a certain wattage, without using a temperature controller, and is used at the saturation temperature of the hot plate. I was doing it. However, in order to eliminate energy loss, improve the temperature control of the object to be kept warm, or keep the hot plate temperature at a constant temperature, it is preferable to use a temperature controller. Figures 1 and 2 show the configuration of a heater unit in a conventional electric heat insulator. This heater unit is made of an electrical insulator, and one end is attached to both sides of a wound mica 1 that is divided into two parts. A plurality of protrusions a, a′...j,
j', and by sequentially winding the resistance wire 2 around the plurality of protrusions a, a'...j, j', and clamping them with two pieces of pressure mica 3 (one side is not shown). It consists of and said volume mica 1
When winding the resistance wire 2, start from one end of the mica mica 1, that is, from the lower parts A and A'. Wind it to a and a'. Then, the protrusions a, a' are wound sequentially to the next protrusions b, b', and finally the other ends of the wound mica 1, that is, the protrusions j, j' at the top, are turned and the lead wires 4, Connect to 5. Normally, it is easier to connect the temperature controller 6 when it is installed on the side where the lead wires are taken out, so the temperature controller 6 is located above the heater unit, that is, in the area indicated by diagonal lines. In such a configuration, the resistance of the resistance wire 2 may vary due to manufacturing variations or the resistance wire 2 may be wound with mica 1.
Since there are variations when winding the wire, it is necessary to change the length of the resistance wire 2 in order to obtain a constant wattage. In general, the variation in resistance due to resistance wire 2 lot is usually plus or minus 5%, and plus or minus 5%.
%, as shown in Figure 2, the resistance wire 2 is wound from the protrusions a, a' at one end of the wound mica 1, and is finally connected to the lead wires 4, 5 from the protrusions i, i'. be done. On the other hand, if the resistance variation of the resistance wire 2 is -5%, as shown in FIG. 2 is wound up to the last protrusion j, j' at the other end of the wound mica 1, and then connected to the lead wires 4, 5. In this case, as can be seen by comparing the two, there is a difference in the winding pattern of the resistance wire 2 in the lower part where the temperature controller 6 is located, so naturally the amount of heat given to the temperature controller 6 will be different. As a result, there was a problem in that the hot plate temperatures were different.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
To provide an electric heat insulator that can always control the temperature of a hot plate at a constant level.

Structure of the Invention In order to achieve the above object, the present invention provides for adjusting the length of a resistance wire that is sequentially wound around a plurality of protrusions provided at a certain interval from one end to the other end of the wound mica constituting the heater unit. This is done at the center of the wound mica. According to this configuration, when absorbing variations in the resistance of the resistance wire, the length of the resistance wire is adjusted at the center of the wound mica. The winding pattern of the resistance wire in the temperature controller part located at the end of the heater unit remains unchanged, so the length of the resistance wire must be adjusted to absorb variations in the resistance of the resistance wire. However, it is possible to always obtain a constant amount of heat.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 3 to 5, 11 is a frame plate having an opening 11a in the center, 12 is attached to the back surface of the frame plate 11, and installation legs 13 are attached at the bottom.
a back plate 14 having an opening 11 of the frame plate 11;
This hot plate 14 faces the back plate 1.
It is installed on 2. Reference numeral 15 denotes a heater unit which is pressed against the back surface of the hot plate 14 by a pressing spring plate 19, and this heater unit 15 is
As shown in FIG.
A plurality of protrusions a, a'...j, j' are provided at a certain interval from one end to the other end, and the protrusions a, a'...j, j' are sequentially wound around the plurality of protrusions a, a'...j, j'. Resistance wire 17 and two pieces of pressure mica 1 that clamp these
8, and this heater unit 15 is pressed against the hot plate 11 by a presser spring plate 19 via a reflection plate. A temperature controller 20 is located on the side from which the lead wires 21 and 22 of the heater unit 15 are taken out and is fixed to an electrically insulating mica plate 23.
Further, the electrically insulating mica plate 23 is attached to a support plate 24 fixed to the heater unit 15. 25 is a power supply section.

Next, how to wind the resistance wire 17 in the heater unit 15 will be explained based on FIG. The resistance of the resistance wire 17 is due to manufacturing variations and variations when winding the resistance wire 17 around the mica 16.
In order to obtain a constant wattage, it is necessary to adjust the length of the resistance wire 17, but in this case, the resistance wire 17 is connected from one end of the mica wound 16 divided into two parts, that is, from the lower parts A and A'. Start winding, and turn at both side end protrusions a and a' of the winding mica 16,
Thereafter, it is wound in the same way from protrusions b and b' to c and c' in sequence. In this case, the resistance value of the resistance wire 17 to be used is first measured, and if the resistance value is larger than the standard, the length of the resistance wire 17 is shortened, and conversely, if the resistance value is smaller than the standard, the resistance wire 17 is
It is sufficient to adjust the length of the wound mica 16 to a longer length, and the length adjustment is performed at the center of the rolled mica 16. That is, if the resistance value of the resistance wire 17 is larger than the standard, the fifth
As shown in the figure, the resistance wire 17 is wound from the projections d, d' at the center of the wound mica 16 to f, f'.
If the resistance value is still higher, the length of the resistance wire 17 can be reduced by winding it from the projections d, d' to the protrusions g, g'. In this case, if the resistance wire 17 is wound at the same pitch, the temperature at the center of the wound mica 16 will naturally become higher, and therefore the temperature at the center of the wound mica 16 will increase.
In order to make the temperature uniform, it is necessary to wrap the resistance wire 17 tightly around the wound mica 16 and loosely around the center.

In this way, when adjusting the length of the resistance wire 17, it can be done at the center of the wound mica 16, that is, at the center of the heater unit 15, so that the part RO where the temperature controller 20 is located has a constant resistance. line 17
Since it is in a wound state, stable temperature control is possible and the temperature distribution of the hot plate 14 is also made uniform.

Effects of the Invention As described above, according to the present invention, when absorbing variations in the resistance of the resistance wire, the length of the resistance wire is adjusted at the center of the wound mica. The winding pattern of the resistance wire in the temperature controller part that is installed as a
Even if the length of the resistance wire is adjusted, the temperature controller can always control the temperature stably, so that the temperature distribution on the hot plate can be made uniform.

[Brief explanation of the drawing]

1 and 2 are front views showing a conventional heater unit, FIG. 3 is a back view of an electric heat insulator showing an embodiment of the present invention, and FIG. 4 is a side sectional view of the electric heat insulator, and FIG. FIG. 5 is a front view of the heater unit in the electric heat insulator. 11...Frame plate, 11a...Central opening, 12...
...Back plate, 14...Heat plate, 15...Heater unit, 16...Wound mica, 17...Resistance wire, 19...
...Press spring plate, 20...Temperature controller, a, a'~
j, j′...Protrusion.

Claims (1)

[Claims] 1. A frame plate having an opening in the center, a back plate attached to the back side of the frame plate, a heating plate facing the opening of the frame plate, and a presser spring plate attached to the back side of the heating plate. The heater unit includes a heater unit fixed by the back plate, and a temperature controller installed at an end of the heater unit near the power supply, and the heater unit includes a wound mica and one end of the wound mica. An electric heat insulator having a resistance wire wound sequentially around a plurality of protrusions provided at a certain interval toward the other end, and the length of the resistance wire is adjusted at the center of the wound mica. .