JP3925205B2 - Electric heater protection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric heater protection structure excellent in waterproofness, and is suitable, for example, as an electric heater structure that is mounted outside a passenger compartment of a vehicle and is immersed in water due to adhesion of frost or the like.
[0002]
[Prior art]
In the Japanese Patent Application No. 2001-346197, the applicant of the present invention directly introduced the compressor discharge gas refrigerant (hot gas) into the indoor heat exchanger (evaporator) at the time of heating in winter. In a vehicle air conditioner that exhibits a hot gas heating function used as a radiator for a gas refrigerant, an accumulator is provided on the outlet side of the indoor heat exchanger, and an electric heater is attached to the accumulator, and the liquid refrigerant in the accumulator is supplied to the electric heater. The one that heats by is proposed.
[0003]
The liquid refrigerant is heated by the electric heater to evaporate the liquid refrigerant, thereby increasing the suction pressure of the compressor and increasing the compression work of the compressor, thereby improving the heating performance during hot gas heating. .
[0004]
[Problems to be solved by the invention]
By the way, in the refrigeration cycle of a vehicle air conditioner, since the accumulator is mounted in a part outside the passenger compartment such as the engine room together with the compressor, if the vehicle is left for a long time at night in winter, the outer surface of the accumulator In the same manner as in the above, the temperature becomes 0 ° C. or lower, frost adheres to the outer surface of the accumulator, and the electric heater may be submerged.
[0005]
The electric heater has a structure in which the heating element is covered with an electrical insulating material, but if it is immersed in water, moisture may enter from the lead wire lead-out part electrically connected to the heating element and there is a risk of leakage. There was a problem of becoming higher.
[0006]
An object of this invention is to provide the electric heater protective structure excellent in waterproofness in view of the said point.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, at least an outer layer film member (43a) and an inner layer film member (43c) are used as film members for sealing the heating element (41) of the electric heater (40). A laminated film member (43) laminated with
The heating element (41) includes a heating element (41a), lead wires (42) electrically connected to both ends of the heating element (41a), and an elastic insulating sheet material in which the heating element (41a) is embedded ( 41b, 41c)
Outer layer film member (43a) is made of a material which satisfies the heat resistance and cold resistance, the inner layer film member (43c) is a thermally weldable resin have a higher use temperature of the electric heater (40) melting point, and , Consisting of a resin having a polar group in the molecular structure,
Inside the heating element portion of the inner layer film member (43c) (41) Gasa Ndouitchi shape scissors write rare,
Together with the peripheral portion of the heating element the inner layer film member (43c) between each other are thermally welded except for the drawer portion of the lead wire (42) (41) is sealed,
In order to seal the lead- out portion of the lead wire (42), the adhesive (44) injected into the gap between the lead wire (42) and the inner-layer film member (43c) causes the inner-layer film member (43c) and the interface between the adhesive (44) is bonded, by dressing leads (42) (42a) and the adhesive (44) and is bonded, the gap portion, characterized in that it is sealed.
[0008]
According to this, the heating element (41) is sandwiched between the inner film members (43c) of the laminated film member (43), and the peripheral portion of the heating element (41) is located between the inner film members (43c) . The gap between the lead wire (42) and the inner layer film member (43c) is sealed with an adhesive (44) between the lead wire (42) and the inner layer film member (43c) which are sealed by heat welding and electrically connected to the heating element portion (41). Can be sealed.
[0009]
In particular, by using a resin having a polar group in the molecular structure as the material of the inner layer film member (43c), the inner layer film member (43c) itself has adhesiveness, so that the adhesive (44) can be reliably adhered. The gap around the lead wire (42) can be well sealed over a long period of time.
[0010]
As a result, even when the electric heater (40) is used in an environment where the electric heater (40) is immersed in water due to adhesion of frost, the moisture intrusion into the heating element (41) is caused by the bonding portion between the inner film member (43c) and the adhesive ( The lead wire sealing structure according to 44) can be reliably prevented and the waterproof effect can be enhanced. Therefore, it is possible to prevent leakage due to moisture intrusion into the heating element (41).
[0011]
And since the outer layer film member (43a) which plays the role which coat | covers the outer surface of the whole electric heater (40) is comprised with the material which satisfies heat resistance and cold resistance, the heat resistance with respect to the high temperature of the electric heater (40), In addition, it is possible to satisfactorily ensure cold resistance against low temperature usage environments where frost adheres.
[0012]
Like invention of Claim 2, what is necessary is just to comprise the outer-layer film member (43a) in Claim 1 with a polyethylene terephthalate specifically.
[0014]
As in the third aspect of the present invention , in the first or second aspect, the inner layer film member (43c) may be made of ethylene vinyl alcohol.
[0019]
As in the fourth aspect of the present invention , in any one of the first to third aspects, the covering material (42a) of the lead wire (42) is specifically silicone rubber, and the adhesive (44). ) May be specifically composed of a silicone-based adhesive containing a silicone component.
[0023]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the laminated film member (43) has a gas barrier function between the outer layer film member (43a) and the inner layer film member (43c). An intermediate layer film member (43b) is provided.
[0024]
According to this, since the intermediate layer film member (43b) exhibits a gas barrier function, it is possible to prevent oxygen, moisture, and the like in the surrounding atmosphere from reaching the inner layer film member (43c). If these oxygen, moisture, etc. reach the inner layer film member (43c), the inner layer film member (43c) deteriorates and causes a reduction in the welding strength of the heat-welded portion, and as a result, the sealing action of the heat-welded portion. However, according to the fourth aspect, since the intermediate layer film member (43b) exhibits a gas barrier function, the inner layer film member (43c) is prevented from being deteriorated over a long period of time, and the heat-welded portion has a good sealing effect. Can be maintained.
[0025]
Like invention of Claim 6, what is necessary is just to comprise the intermediate | middle layer film member (43b) in aluminum foil in Claim 5.
As in the seventh aspect of the present invention, the electric heater waterproof structure according to any one of the first to sixth aspects can be suitably used as a heating means for the refrigerant in the refrigeration cycle.
[0026]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 illustrates a schematic configuration of a vehicle air conditioner to which the electric heater protection structure according to the first embodiment is applied. The compressor 10 is driven by a water-cooled vehicle engine 12 via an electromagnetic clutch 11.
[0028]
The discharge side of the compressor 10 is connected to a condenser 14 via a cooling electromagnetic valve 13, and the outlet side of the condenser 14 is connected to a liquid receiver 15 that separates gas-liquid refrigerant and stores liquid refrigerant. . The condenser 14 is an outdoor heat exchanger that is arranged in the vehicle engine room together with the compressor 10 and the like and exchanges heat with the outside air (cooling air) blown by the electric cooling fan 14a.
[0029]
The outlet side of the liquid receiver 15 is connected to a temperature type expansion valve 16 constituting a cooling decompression device. The outlet side of the temperature type expansion valve 16 is connected to the inlet side of the evaporator 18 via a check valve 17. The outlet side of the evaporator 18 is connected to the suction side of the compressor 10 via an accumulator 19.
[0030]
From the discharge side of the compressor 10 to the suction side of the compressor 10 through the cooling solenoid valve 13 → the condenser 14 → the liquid receiver 15 → the temperature type expansion valve 16 → the check valve 17 → the evaporator 18 → the accumulator 19. An ordinary cooling refrigeration cycle C is constituted by the returning closed circuit.
[0031]
The accumulator 19 has a cylindrical tank main body portion 19a, and stores the liquid refrigerant by separating the gas-liquid refrigerant from the outlet of the evaporator 18 inside the tank main body portion 19a. Then, a U-shaped refrigerant outlet pipe 19b is arranged inside the tank main body 19a, and the gas refrigerant in the upper part of the tank main body 19a is sucked from the upper end opening 19c of the refrigerant outlet pipe 19b, and the refrigerant outlet pipe 19b A small amount of liquid refrigerant in which oil is dissolved is sucked from an oil return hole (not shown) that opens to the bottom near the inner bottom of the tank main body 19a, and this liquid refrigerant is mixed into the gas refrigerant to the compressor 10 side. It comes to derive.
[0032]
On the other hand, a hot gas bypass passage 20 that bypasses the condenser 14 and the like is provided between the discharge side of the compressor 10 and the inlet side of the evaporator 18. The bypass passage 20 includes a heating electromagnetic valve 21 and a throttle. 21a is provided in series. The restrictor 21a forms a heating decompression device, and can be constituted by a fixed restrictor such as an orifice or a capillary tube. A heating hot gas heater cycle H is constituted by a closed circuit that returns from the discharge side of the compressor 10 to the suction side of the compressor 10 via the heating solenoid valve 21 → the throttle 21 a → the evaporator 18 → the accumulator 19.
[0033]
The air conditioning case 22 of the vehicle air conditioner constitutes an air passage through which air flows toward the passenger compartment. Air is blown through the air conditioning case 22 by an electric air conditioning blower 23.
[0034]
In addition, on the suction side of the air-conditioning blower 23, an outside air suction port 70 for sucking in outside air (air outside the vehicle compartment), an inside air suction port 71 for sucking in inside air (vehicle room air), and inside / outside air switching means are configured. An inside / outside air switching door 72 is provided.
[0035]
The evaporator 18 is an indoor heat exchanger installed in the air conditioning case 22, and in the cooling mode, the refrigerant circulates by the cooling refrigeration cycle C, and the air conditioner blower 23 by the refrigerant evaporation (heat absorption) in the evaporator 18. Since the blast air is cooled, it serves as a cooler. Further, in the heating mode, the evaporator 18 serves as a radiator because the high-temperature refrigerant gas (hot gas) from the hot gas bypass passage 20 flows in and heats the air.
[0036]
In the air conditioning case 22, a hot water heating heat exchanger 24 is installed on the air downstream side of the evaporator 18 to heat the blown air using hot water (engine cooling water) from the vehicle engine 12 as a heat source. By the way, the hot water heating heat exchanger 24 serves as a main heating means for heating the passenger compartment. On the other hand, an evaporator (indoor heat exchanger) forming a radiator by the hot gas heater cycle H is used. ) 18 constitutes auxiliary heating means.
[0037]
On the other hand, a defroster air outlet 31, a face air outlet 32, and a foot air outlet 33 are provided on the most air downstream side of the air conditioning case 22, and these air outlets 31 to 33 are respectively connected by mode switching doors 34 to 36. It is selectively opened and closed.
[0038]
The accumulator 19 is provided with an electric heater 40 as a heating means for heating the liquid refrigerant therein. This electric heater 40 is for improving the heating performance in the hot gas heating mode, and a specific mounting example of the electric heater 40 is shown in FIG. As shown in FIG. 2, the electric heater 40 is mounted and fixed to the lower part of the outer peripheral surface of the cylindrical tank body 19 a of the accumulator 19.
[0039]
Next, a specific structure of the electric heater 40 will be described with reference to FIGS. 3 to 7. FIG. 3 shows a heating element portion 41 of the electric heater 40 and a lead wire 42 for energizing the heating element portion 41. Show. Here, the heating element 41 has a wire-like heating element 41a formed in a meandering shape, and lead wires 42 are electrically connected to both ends of the heating element 41a, and the heating element 41a is connected to silicone rubber. The structure is embedded in elastic insulating sheet materials 41b and 41c made of such a rubber-based material.
[0040]
Specifically, two elastic insulating sheets 41b and 41c are sandwiched between the heating elements 41a, and the two upper and lower elastic insulating sheets 41b are vulcanized and molded in a mold, whereby two pieces of elastic insulation are obtained. The heating elements 41a can be embedded in the elastic insulating sheet materials 41b and 41c by bonding the sheet materials 41b and 41c together. Thereby, the heat generating body part 41 is formed in the rectangular thin plate shape.
[0041]
And in this embodiment, it has the structure which sandwiches and draws out the heating-element part 41 and the lead-out part of the lead wire 42 from above and below by the laminated film member 43 shown in FIGS.
[0042]
In this example, the laminated film member 43 has a three-layer laminated film structure in which an outer layer film member 43a, an intermediate layer film member 43b, and an inner layer film member 43c are laminated. The outer layer film member 43a forms a base film layer excellent in strength, heat resistance, cold resistance, water resistance, chemical resistance and the like. Polyethylene terephthalate (hereinafter abbreviated as PET) is suitable as a specific material satisfying such various characteristics.
[0043]
PET has a physical property of melting point: about 250 ° C., glass transition temperature: about 70 ° C., embrittlement temperature: −75 ° C. or less, and is a transparent crystalline polymer material with excellent properties described above. . PET has unique crystallinity and can control mechanical properties and thermal properties by controlling crystallization by processing conditions such as heating / cooling and stretching, and changing the crystalline state and orientation state. There is. The outer layer film member 43a is particularly superior in properties such as strength and heat resistance to the later described inner layer film member 43c.
[0044]
The intermediate layer film member 43b forms a gas barrier film layer that prevents the permeation of moisture and gas. A metal foil is preferable as a material that exhibits the function of such a gas barrier film layer, and among these metal foils, aluminum foil is most preferable in terms of formability, material cost, and the like.
[0045]
The intermediate layer film member 43b functions to prevent deterioration of the inner layer film member 43c, specifically, a decrease in thermal welding strength, by preventing moisture and gas from entering the inner layer film member 43c described later. The outer layer film member 43a can also protect the aluminum foil of the intermediate layer film member 43b by using a PET film that is particularly excellent in heat resistance and cold resistance as the material of the outer layer film member 43a.
[0046]
The inner layer film member 43 c forms a sealant film layer that performs a sealing action between the upper and lower laminated film members 43. Usually, as the material of the sealant film layer, a material having a low melting point and easy heat welding (heat sealing) is selected. However, in this embodiment, the operating temperature of the electric heater 40 is as high as 120 ° C. It is necessary to select a film material having a high melting point. Among general-purpose sealant films, polypropylene (PP) has the highest melting point (about 144 ° C.). However, since polypropylene does not have a polar group in the molecular structure, it has poor adhesion. As a result, it becomes difficult to bond the inner layer film member 43c and the lead wire 42 drawing portion.
[0047]
Therefore, in this embodiment, ethylene vinyl alcohol (EVOH) having a polar group in the molecular structure and having a melting point of about 160 ° C. and sufficiently higher than the heater operating temperature is selected as the material of the inner layer film member 43c. ing. Thereby, the adhesiveness between the inner layer film member 43c and the lead wire 42 can be improved.
[0048]
Next, the manufacturing method of the electric heater 40 according to the present embodiment will be described. First, as shown in FIG. 3, a heating element 41a connected to the lead wire 42 is embedded in elastic insulating sheet materials 41b and 41c. The heating element portion 41 is formed.
[0049]
Further, the outer layer film member 43a, the intermediate layer film member 43b, and the inner layer film member 43c constituting the laminated film member 43 are laminated, and the layers are integrally bonded to each other by bonding to form a laminated structure having a three-layer laminated structure. A film member 43 is formed.
[0050]
Next, as shown in FIGS. 4 and 5, the heating element 41 is sandwiched between the laminated film members 43 from the upper and lower sides, and the heating element 41 is sealed with the laminated film member 43. Explaining this process more specifically, the heating element portion 41 is sandwiched between the upper and lower sides by the laminated film member 43 in a predetermined mold space.
[0051]
Thereafter, while applying pressure between the laminated film members 43 on both the upper and lower sides in this mold space, a temperature equal to or higher than the melting point (about 160 ° C.) of the inner layer film member 43c forming the sealant film layer, specifically 160 ° C. to 210 ° C. Heating is performed in a temperature range of about 0 ° C., and the upper and lower inner layer film members 43c are heat welded (heat sealed). 6 and 7 show a state after the thermal welding between the inner layer film members 43c is finished. 43d shows the heat welding area.
[0052]
Here, since the lead-out portion of the lead wire 42 has a circular curved surface shape, heat welding cannot be performed. Therefore, the thermal welding process is performed excluding the lead wire 42 drawing portion. Further, in the heat welding region 43d where the upper and lower inner film members 43c are in direct contact with each other, a portion where heat welding is not performed remains at an arbitrary position, and the following vacuuming passage portion ( (Not shown).
[0053]
Next, as shown in FIGS. 6B and 7C, the adhesive 44 is injected into the gap between the inner film member 43c of the laminated film member 43 on both the upper and lower sides and the covering material 42a of the lead wire 42. Then, the gap is sealed with the adhesive 44. Thereby, the lead-out part of the lead wire 42 can be sealed.
[0054]
Here, as a specific material of the inner layer film member 43c, as described above, ethylene vinyl alcohol (EVOH) which is a resin having a polar group in the molecular structure is selected, so that the inner layer film member The interface between 43c and the adhesive 44 can be securely bonded. Further, the covering material 42a of the lead wire 42 is made of silicone rubber, and the silicone material containing a silicone component is selected as the material of the adhesive 44, whereby the covering material 42a of the lead wire 42 and the adhesive 44 The adhesive strength can be secured.
[0055]
Next, the suction part of the vacuuming device is connected to the passage part for vacuuming formed from the part where the thermal welding is not performed, and the inside of the laminated film member 43 is vacuumed. Here, the passage for vacuuming communicates between the peripheral portion of the heating element portion 41 and the outside of the laminated film member 43, so that it is connected to the peripheral portion of the heating element portion 41 built in the laminated film member 43. Residual gas components such as oxygen, moisture, and the like can be discharged to the outside of the laminated film member 43.
[0056]
When these gas components such as oxygen, moisture, and the like remain inside the laminated film member 43, the inner film member 43c of the laminated film member 43 is promoted to be deteriorated, and the heat-sealed portion of the inner film member 43c is sealed. However, it is possible to discharge gas components such as oxygen, moisture and the like to the outside by performing the evacuation step, and avoid deterioration of the inner layer film member 43c.
[0057]
After completion of the evacuation step, the evacuation passage portion formed from the unwelded portion of the heat welding is thermally welded and sealed. Thereby, the electric heater 40 can be completed.
[0058]
Since the entire shape of the electric heater 40 manufactured in this way is a flexible thin plate shape that can be easily deformed, the electric heater 40 is bent along the outer peripheral surface of the tank body 19a as shown in FIG. It can be easily mounted on the outer peripheral surface of the main body 19a.
[0059]
By the way, in the electric heater 40, the peripheral portion of the heating element portion 41 built in the laminated film member 43 can be reliably sealed by the heat welding portion 43 d of the inner layer film member 43 c of the laminated film member 43. In addition, a gap between the inner film member 43 c of the laminated film member 43 and the covering material 42 a of the lead wire 42 can be sealed with an adhesive 44. As a result, the moisture intrusion path to the heating element portion 41 can be reliably sealed, and the waterproofness of the electric heater 40 can be greatly enhanced.
[0060]
Further, by using a PET film as the outer film member 43a of the laminated film member 43, both the heat resistance and the cold resistance can be satisfactorily exhibited, and an electric heater that can be used for a long time with respect to a temperature change of about -40 ° C to 120 ° C. 40 can be provided. Moreover, the aluminum foil of the intermediate | middle layer film member 43b can be protected with a PET film.
[0061]
Further, since the aluminum foil of the intermediate layer film member 43b can prevent gas and moisture from passing therethrough, the inner layer film member 43c is prevented from being deteriorated due to the invasion of gas, moisture, etc., and the inner layer film member 43c is thermally welded. The sealing action of the portion 43d can be stably maintained over a long period of time.
[0062]
Next, the refrigerant heating action of the electric heater 40 will be described. In the hot gas heater cycle H, in order to secure the refrigerant flow rate during hot gas heating and the oil return amount to the compressor 10, An accumulator 19 is provided. Since the gas-liquid interface of the refrigerant is formed inside the accumulator 19, the refrigerant state on the low pressure side is balanced so that the refrigerant becomes a saturated gas on the outlet side of the evaporator 18.
[0063]
And since the electric heater 40 is attached over the whole periphery of the lower part of the outer peripheral surface of the accumulator 19, when the electric heater 40 is energized, the liquid refrigerant collected in the lower part in the accumulator 19 can be heated and evaporated. Here, since the electric heater 40 heats the liquid refrigerant instead of the gas refrigerant, the heat transfer rate is higher than that of the gas refrigerant. Accordingly, the amount of heat generated by the electric heater 40 can be efficiently transmitted to the refrigerant.
[0064]
As the liquid refrigerant in the accumulator 19 evaporates, the pressure of the refrigerant sucked in the compressor 10 rises and the density of the refrigerant sucked in the compressor 10 rises, so that the weight flow rate of refrigerant discharged from the compressor 10 increases. As a result, the discharge pressure of the compressor 10 increases. Thereby, the compression work of the compressor 10 increases. As a result, the amount of heat released from the evaporator 18 can be effectively increased, and the heating performance during hot gas heating can be improved.
[0065]
(Second Embodiment)
In the first embodiment, as a specific material of the inner layer film member 43c constituting the sealant film material, as described above, ethylene vinyl alcohol (EVOH), which is an adhesive resin having a polar group in the molecular structure, is used. Although used, in the second embodiment, polypropylene (PP) which is a resin having no polar group in the molecular structure is used.
[0066]
Since polypropylene does not have a polar group and has poor adhesiveness, if polypropylene is used as it is, the interface between the inner layer film member 43c and the adhesive 44 becomes poorly bonded, and the sealing action at this interface decreases.
[0067]
Therefore, in the second embodiment, a surface film (primer layer) for increasing the adhesive strength is formed on the surface of polypropylene, and the interface between the inner layer film member 43c and the adhesive 44 is securely adhered to improve the sealing action. Let
[0068]
The melting point of polypropylene is about 144 ° C., which is lower than the melting point of ethylene vinyl alcohol, but is sufficiently higher than the heater operating temperature (for example, 120 ° C.), so there is no problem in terms of heat resistance. Further, by using polypropylene, the thermal welding between the inner layer film members 43c can be performed at a lower temperature than in the case of the first embodiment.
[0069]
(Third embodiment)
In the first embodiment, a PET film is used as a specific material of the outer layer film member 43a that forms the base film material. In the third embodiment, a polyamide (PA) film is used instead of the PET film. .
[0070]
Polyamide has physical properties of melting point: about 220 ° C., glass transition temperature: about 50 ° C., embrittlement temperature: −60 ° C. or less, and has heat resistance, cold resistance, etc. similar to PET. However, since polyamide has a higher water absorption rate than PET, it has a disadvantage over the first embodiment in that it tends to cause volume swelling during freezing of water at 0 ° C. or lower. A surface film may be formed to suppress the volume swelling due to moisture freezing.
[0071]
(Fourth embodiment)
In the said 1st Embodiment, although aluminum foil is used as the intermediate | middle layer film member 43b which makes | forms the gas barrier layer which blocks | prevents permeation | transmission of moisture and gas, in 4th Embodiment, ethylene vinyl alcohol (EVOH) is used instead of aluminum foil. ) Or polyvinyl alcohol (PVA).
[0072]
Although this EVOH or PVA has a gas barrier function lower than that of an aluminum foil, moisture and gas permeation can be suppressed to a considerable extent as compared with the case without the intermediate layer film member 43b.
[0073]
(Other embodiments)
In addition, although 1st Embodiment demonstrated the electric heater using this invention as a heating means of the refrigerant | coolant of a refrigerating cycle, this invention is not limited to this but can apply widely to the electric heater of various uses generally.
[0074]
Further, in the first embodiment, the heating element 41 is sandwiched between the inner layer film members 43c of the two laminated film members 43, and the inner layer film members 43c are thermally welded to each other. One laminated film member 43 having a size corresponding to the laminated film member 43 is prepared, the one laminated film member 43 is bent so that the inner layer film member 43c is inside, and the heating element portion 41 is sandwiched with the sand. It may be sandwiched in a witch shape, and the inner layer film members 43c may be thermally welded together.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle air conditioner to which an electric heater according to a first embodiment of the present invention is applied.
2 is a perspective view showing a state where an electric heater is attached to the accumulator tank of FIG. 1; FIG.
FIG. 3 is a perspective view of a heating element portion and lead wires in the electric heater according to the first embodiment.
FIG. 4 is a perspective view of a laminated film member in the electric heater according to the first embodiment before a heat welding step.
FIG. 5 is an explanatory view showing a laminated structure of laminated film members in the electric heater according to the first embodiment.
6A is a perspective view after completion of a heat welding process of a laminated film member in the electric heater of the first embodiment, and FIG. 6B is a cross-sectional view of a lead wire seal portion of the electric heater.
7A is a plan view after completion of the thermal welding process of the laminated film member in the electric heater of the first embodiment, FIG. 7B is a cross-sectional view taken along the line AA in FIG. 7A, and FIG. It is BB sectional drawing of.
[Explanation of symbols]
40 ... electric heater, 41 ... heating element, 42 ... lead wire,
43 ... laminated film member, 43a ... outer layer film member,
43b ... intermediate layer film member, 43c ... inner layer film member, 44 ... adhesive.

Claims (7)

As a film member for sealing the heating element portion (41) of the electric heater (40), a laminated film member (43) in which at least an outer layer film member (43a) and an inner layer film member (43c) are laminated,
The heating element (41) includes a heating element (41a), lead wires (42) electrically connected to both ends of the heating element (41a), and an elastic insulating sheet in which the heating element (41a) is embedded. Material (41b, 41c),
The outer layer film member (43a) is made of a material satisfying heat resistance and cold resistance,
The inner layer film member (43c) is a thermally weldable resin have a higher use temperature melting point of the electric heater (40), and a resin having a polar group in the molecular structure,
Wherein the heating element inside of the inner layer film member (43c) (41) Gasa Ndouitchi shape scissors write rare,
Together with the peripheral portion of the inner layer film member except the lead portion of the lead wire (42) (43c) the heating element portion therebetween is heat-welded (41) is sealed,
To seal the lead-out portion of the lead wire (42), by the lead wire (42) and the inner layer film member (43c) is injected into the gap portion between the adhesive (44), said inner layer film member (43c) and the adhesive (44) are bonded to each other, the covering material (42a) of the lead wire (42) and the adhesive (44) are bonded, and the gap is sealed . An electric heater protection structure characterized by that. The electric heater protection structure according to claim 1, wherein the outer layer film member (43a) is polyethylene terephthalate . The electric heater protection structure according to claim 1 or 2, wherein the inner layer film member (43c) is ethylene vinyl alcohol . The covering material (42a) of the lead wire (42) is silicone rubber, and the adhesive (44) is a silicone-based adhesive containing a silicone component . electric heater protection structure according to one. The laminated film member (43) includes an intermediate layer film member (43b) that exhibits a gas barrier function between the outer layer film member (43a) and the inner layer film member (43c). The electric heater protection structure according to any one of claims 1 to 4 . The electric heater protection structure according to claim 5 , wherein the intermediate layer film member (43b) is an aluminum foil .   7. The electric heater protection structure according to claim 1, wherein the electric heater protection structure is used as a heating means for a refrigerant in a refrigeration cycle.

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