JP2005317268A - Electric heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the damage of a substance to be heated caused the temperature increase of a heating part. <P>SOLUTION: An inside of a sheathing pipe 1 is divided in two chambers for heat generation part X and non-heating part Y in axial direction. On the electric heater, the heat generation part X comprises a heating wire 3, and the non-heating part Y comprises: a first excessive temperature increase prevention means 9; a second excessive temperature increase prevention means 10 with an operation temperature set higher than that of the first excessive temperature increase prevention means 9; a heat transfer member 11 extending from the heat generation part X side, contacting the outer face of the first excessive temperature increase prevention means 9; and a fixing member 12 holding the heat transfer member 11 on the outer face of the first excessive temperature increase prevention means 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly relates to an electric heater used as a heating heat source for liquid or the like.

  Conventional electric heaters include a built-in temperature sensing thermostat to prevent overheating, and a built-in temperature fuse to prevent overheating.

  However, as electric heaters are increasing in capacity, the working temperature of the object to be heated is actually low, but high watt density is required. Therefore, it is necessary to turn on / off the power by sensing the temperature of the heat generating portion earlier.

  In particular, this type of electric heater is often used for liquid heating, and when an abnormality occurs in a thermostat that is trying to control the liquid in the heated apparatus at a constant temperature, the electric heater remains energized in the worst case. The temperature of the heated aqueous solution will rise to the boiling temperature. Also, due to a problem in handling the heated apparatus, the trouble of baking the electric heater cannot be avoided especially when the power is turned on in a state where the heated liquid is not replenished at the time of new installation or maintenance.

  In view of this, there has heretofore been an object that allows the heater to be reused if the electric heater is baked in the shortest time (see, for example, Patent Document 1).

  Further, as a conventional electric heater, one that can quickly shut off a power source is known (see, for example, Patent Document 2).

  Further, as a conventional electric heater, an underwater heater developed for the purpose of keeping the temperature of a viewing fish tank is known. The underwater heater is provided with a plurality of the same heating elements inside the heater body that generates heat by the heating element, and a temperature fuse that cuts off the power supply to the heating element when the heater body is heated outside the water. Is provided inside the heater body in thermal contact with the heat conductor.

  In this way, the underwater heater can detect the temperature inside the heater and operate the temperature fuse when the heater is released to the outside of the water. Through the thermal fuse (see, for example, Patent Document 3).

Utility Model Registration No. 2543980 (page 3, FIG. 1) Japanese Patent Application No. 2002-352937 (2nd page, Fig. 1) JP-A-10-3983 (first page, FIG. 1)

  The electric heater in Patent Document 1 has a structure suitable for a low-capacity electric heater and is not suitable as a high-capacity heater.

  Moreover, the electric heater in Patent Document 2 has a disadvantage that the power supply can be shut off early but the heater cannot be reused. In addition, the electric heater cannot be reused because it uses only a thermal fuse.

  In addition, the underwater heater in Patent Document 3 can operate the temperature fuse by detecting the temperature inside the heater when the heater is released to the outside of the water. Although it is transmitted to the thermal fuse, there is a possibility that the underwater heater does not necessarily function effectively when an abnormal temperature of the heating element occurs when the underwater heater is not discharged into the water.

  According to the present invention, a metallic exterior pipe having a long dimension in a uniaxial direction, and the interior of the exterior pipe are separated into two chambers of a heat generating portion and a non-heat generating portion in the uniaxial direction, and the heat generating portion is In the electric heater including the heating wire provided in the uniaxial direction in the pipe, the non-heating portion includes a first overheating temperature preventing means for turning on / off the power supply at a predetermined temperature, and the first overheating temperature prevention. And a heat transfer member extending from the heat generating portion and in contact with the outer surface of the first overheat prevention unit. And a fixing member that holds the heat transfer member on the outer surface of the first overheat prevention means, the heating wire 3, the first overheat prevention means, and the second overheat temperature. An electric heater is obtained, characterized in that the prevention means are connected in series

  According to the electric heater of the present invention described above, the temperature of the heat generating part is controlled by transferring the heat of the heat generating part faster and more to the temperature controller on the non-heat generating part side by the transmission member. The temperature range is further reduced to extend the life of the heating wire, and in the event of an abnormality, the power supply is shut off or the temperature is controlled quickly by a nearby temperature fuse or temperature controller. Can be prevented, and damage including parts of the object to be heated can be prevented in advance.

  In addition, the heat transfer member employed in the electric heater of the present invention is formed into a planar shape so that the tip portion is in contact with the temperature adjuster, and the heat transfer member and the temperature adjuster are wound around the fixing member. By attaching it, loosening of the adhesion can be prevented.

  The non-heating portion includes a first overheating temperature preventing means for turning on / off the power supply at a predetermined temperature, and a second overheating temperature setting for setting the operating temperature for turning off the power supply higher than that of the first overheating temperature preventing means. A temperature rise prevention means, a heat transfer member extending from the heat generating portion side and in contact with the outer surface of the first overheat rise prevention means, and the heat transfer member on the outer face of the first overheat rise prevention means An electric heater having a holding member, and wherein the heating wire 3, the first over-temperature prevention means, and the second over-temperature prevention means are connected in series. is there.

  Hereinafter, Example 1 of the electric heater according to the present invention will be described. FIG. 1 shows an electric heater according to the first embodiment. FIG. 2 shows a connection configuration of the electric heater shown in FIG. FIG. 3 shows an electric circuit of the electric heater shown in FIG.

  Referring to FIGS. 1 to 3, the electric heater has a metallic exterior pipe 1 having a dimension that is long in one axial direction, and the axial direction of the exterior pipe 1 is two of a heating part X and a non-heating part Y. Separated into chamber areas.

  The heat generating part X includes a lid-shaped sealing member 2 that seals the opening on the distal end side of the exterior pipe 1, a heat generation line 3 that is provided in a spiral shape in the uniaxial direction within the exterior pipe 1, and a heat generation line 3. An insulating core 4 wound around the outer peripheral surface at the heat generating portion X, an insulating filler 5 such as magnesium oxide (MgO) filled between the exterior pipe 1 and the heating wire 3, and the core 4 And an insulative core holding member 6 provided on the front end surface.

  A guide core 7 that is in contact with the rear end surface of the core 4 in the exterior pipe 1 is provided at a boundary portion between the heat generating portion X and the non-heat generating portion Y. The core 4 is incorporated by a core holding member 6 and a guide core 7 so as to be positioned at the axial center of the exterior pipe 1, and the heating wire 3 is predetermined between the inner surface of the exterior pipe 1 via the filler 5. Are provided at intervals of. The lid-shaped sealing member 2 is fixed to the exterior pipe 1 by welding or the like.

  The non-heat generating portion Y is connected to a pair of lead members 8a and 8b connected to both ends of the heat generating wire 3 in the outer pipe 1 of the heat generating portion X and extending to the non-heat generating portion Y, and one lead member 8a. A temperature controller (first overheat prevention means) 9 such as a thermostat, and a temperature fuse (second overheat prevention means) 10 for a safety circuit connected to the other lead member 8b, The heat transfer member 11 extends from the core 4 and is in contact with the outer surface of the temperature adjuster 9, and the fixing member 12 holds the heat transfer member 11 on the outer surface of the temperature adjuster 9. The heat transfer member 11 is made of a plate portion and a rod-shaped portion, and the extending end side of the rod-shaped portion extends into the core 4.

  The temperature controller 9 controls the temperature of the heating wire 3 by turning on and off the power supply at a predetermined temperature. The temperature fuse 10 is set to have an operating temperature for turning off the power higher than the set temperature of the temperature controller 9. The lead members 8a and 8b are long and thin metal bars. The fixing member 12 uses a tape that is excellent in insulation and heat resistance. In addition to the tape, a tube having insulating properties and heat resistance may be used.

  Furthermore, one lead member 8a and one lead wire 9a of the temperature controller 9 are respectively connected to the connecting pipe 13a by crimping the connecting pipe 13a from the outside by inserting the end portions into the connecting pipe 13a. The other lead wire 9b of the temperature controller 9 extends from the rear end of the exterior pipe 1 to the outside of the non-heat generating portion Y and is connected to one power cord (not shown).

  The other lead member 8b and one lead wire 10a of the thermal fuse 10 are connected to each other by crimping the connection tube 13b from the outside by inserting respective end portions into the connection tube 13b. The other lead wire 10b of the thermal fuse 10 extends from the rear end of the exterior pipe 1 to the outside of the non-heat generating portion Y and is connected to the other end of the power cord. A sealing member 15 that seals the rear end opening is provided at the rear end of the exterior pipe 1. The sealing member 15 uses a silicone sealant or a molded rubber seal.

  In addition, an insulating tube 16a is attached to one lead member 8a and the connecting tube 13a. An insulating tube 16b is attached to the other lead member 8b, the temperature fuse 10, the one lead wire 10a of the temperature fuse 10, and the connection tube 13b.

  A fixing plate 21 is provided on the outer peripheral surface of the exterior pipe 1 in the non-heat generating portion Y. The fixed plate 21 is a part for attaching the electric heater to a device (not shown). The fixed plate 21 can be attached to the container or the like that stores the liquid of the heated apparatus by the fixed plate 21, for example. The guide core 7 has three or more holes 7a, 7b, 7c. Two lead members 8a and 8b are provided in the two holes 7a and 7b of the holes 7a, 7b and 7c so as to penetrate through the guide core 7 located in the heat generating portion X and the non-heat generating portion Y. .

  The heat transfer member 11 interlocks the heat of the heat generating portion X and abuts it on the side surface of the temperature controller 9 so that the temperature of the temperature controller 9 can be quickly adjusted by the heat of the heat transfer member 11. To. The heat transfer member 11 is made of a material having a high heat transfer rate, for example, a metal rod such as copper or gold, for the purpose of transferring heat faster from the inside of the heat generating part X to the temperature controller 9. A stable and quick thermal response performance is obtained by fixing the tip of the member 11 in contact with the surface of the temperature controller 9.

  It is desirable that the heat transfer member 11 uses a thick material for transferring more heat to the temperature controller 9 faster and making it respond quickly. In particular, the heat transfer member 11 is fixed in contact with one surface of the temperature controller 9. It is desirable that the portion has a shape having at least a large area. In this case, if one surface of the temperature controller 9 is a flat surface, the heat transfer member 11 is a flat surface.

  In such an electric heater, the heat transfer member 11 is incorporated, so that the temperature can be adjusted by transferring heat to the temperature controller 9 more quickly than the heat generating part X. Shut off the power.

  In addition, the electric heater in the embodiment is an example in which the temperature regulator 9, the heating wire 3, and the temperature fuse 10 are wired in series, and the temperature fuse 10 having a higher set temperature than the temperature regulator 9 is connected in series. doing. Therefore, when the heat transfer from the heat generating part X is delayed or the temperature controller 9 causes an abnormal operation and the heat generating part X reaches an excessive temperature, the temperature fuse 10 attached in series and having a high set temperature is operated. A reliable shut-off can be performed.

  Further, in the electric heater, as shown in FIG. 3, the temperature controller 9, the heating wire 3, and the temperature fuse 10 are wired in series. However, as shown in FIG. In addition, the heating wire 3 may be wired in series.

  Further, in the electric heater, a safety circuit can be provided even if a temperature controller (second overheating temperature prevention means) different from the temperature controller 9 is incorporated in the electric circuit in place of the temperature fuse 10 shown in FIGS. Can be formed. In this case, by adopting a temperature controller different from the temperature controller 9 that has a higher set temperature than the temperature controller 9, heat transfer from the heat generating part X is delayed or the temperature controller 9 operates. The power supply can be reliably shut off by operating when the heat generating part X reaches an excessively high temperature due to an abnormality.

  The electric heater of the present invention can be used in conformity with the purpose of heating, adjusting the temperature, keeping warm and preventing freezing of the liquid.

It is sectional drawing which shows Example 1 of the electric heater which concerns on this invention. It is a perspective view which shows the internal structure of the electric heater shown in FIG. It is an electric circuit diagram of the electric heater shown in FIG. FIG. 4 is an electric circuit diagram showing an example instead of the electric circuit diagram of the electric heater shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exterior pipe 2 Sealing member 3 Heating wire 4 Core 5 Filler 7 Guide core 6 Core holding member 8a, 8b Lead member 9 Temperature controller 10 Thermal fuse 11 Heat transfer member 12 Fixing member 13a, 13b Connection pipe 16a, 16b Tube 21 Fixing plate X Heating part Y Non-heating part

Claims (4)

A metallic outer pipe having a long dimension in a uniaxial direction, and the inside of the outer pipe is separated into two chambers of a heat generating portion and a non-heat generating portion in the uniaxial direction, and the heat generating portion is uniaxially arranged in the outer pipe. In the electric heater including the heating wire provided in
The non-heat generating portion includes a first overheating temperature preventing means for turning on / off the power supply at a predetermined temperature, and a second operating temperature for setting the operating temperature for turning off the power supply higher than the first overheating temperature preventing means. An overheating temperature preventing means; a heat transfer member extending from the heat generating portion side and in contact with an outer surface of the first overheating temperature prevention means; and the heat transfer member of the first overheating temperature prevention means. An electric heater comprising: a fixing member held on an outer surface, wherein the heating wire, the first overheating temperature prevention means, and the second overheating temperature prevention means are connected in series.   2. The electric heater according to claim 1, wherein at least a portion of the heat transfer member that is in contact with an outer surface of the first overheat prevention means has a larger area than other portions. heater.   2. The electric heater according to claim 1, wherein the first overheating temperature preventing means is a temperature controller, and the second overheating temperature preventing means is a temperature fuse. 2. The electric heater according to claim 1, wherein the first over-temperature prevention means and the first over-temperature prevention means are temperature regulators having different operating temperatures.

Images