JPH10241749A - Reopening method for sealed resin-made case, and resin-made case member applied with reopening method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reopen a resin-made case, without effecting an incorporated electronic part by forming a through-hole on the wall surface of a resin case using a heat bar, and inserting a voltage-applying terminal from the through-hole to apply voltage to a resistant heating element in the resin case inside, thereby fusing resin on a joint surface. SOLUTION: A heat bar 40 is abuttingly pressed to the opening part 14 of a battery case to drill a through-hole 13, and a place, on which the heat bar 40 abuts, is preferably near to both the end parts of an incorporated resistive heating element 20. A voltage-applying terminal is inserted into the through- hole 13, formed on the opening part 14 to be made abutting on the heating element 20, and voltage is applied to a fuse resin on a joint surface. Then, a cover 12 is separated from a case main body to open the battery case, because a force is applied in a separating direction in the case main body and a cover 12. A heating tip may be used for the through-hole 13 and is also integrally formed previously in forming the case, and voltage can be applied by using the thorough-hole 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article formed of a thermoplastic resin, for example, a heating element based on electric resistance (hereinafter referred to as a "resistance heating element") sandwiched between joint surfaces of a case body and a cover. Then, in a battery case or the like mounted on an electronic device or the like which is welded and sealed by the heat generated, when the battery case sealing is reopened, the resistance heating element is heated again (using) and the case body and cover are used again. And a resin case member to which the resealing method is applied.

[0002]

2. Description of the Related Art An electronic component is built in a case main body and a cover molded of a thermoplastic resin, and when the case main body and the cover are joined together, the joining method using ultrasonic waves or high-frequency electromagnetic induction requires the electronic component to be built in There is a risk of triggering a bad factor. Therefore, a welding method using a resistance heating element has been proposed. The method is such that a resistance heating element is sandwiched between the joining surfaces of the case body and the cover, and a voltage is applied to the resistance heating element to generate heat, thereby melting and fusing the resin on the joining surface. This is a method in which the application is stopped, the melt-fused portion is cured, and the case body and the cover are welded and bonded. According to this method, the case body and the cover can be instantaneously integrated.

[0003] Thereafter, for example, in a process of producing a resin case in which electronic parts are built, it is necessary to reseal the resin case for some reason, or the resin case in which the electronic parts are built has a long life. When discarding the electronic component, it is necessary to reseal the resin case, take out the built-in electronic component, and distinguish the molded product from the electronic component. In the conventional reopening method, a tool with a thin flat end like a flathead screwdriver is inserted into the gap between the joint surface of the case body and the cover, and it is pryed open. Often, tools are inserted through the mouth and pry open.

However, in either case, the built-in electronic components are damaged or violent vibration is applied to cause a defective factor. Therefore, when the electronic components are used again, the reliability is poor and cannot be recycled. Therefore, the energized terminal of the resistance heating element is drawn out of the case, and when the case is resealed, a voltage is applied to the drawn energized terminal to melt the joint surface by reheating and the fused part is formed. A method of separating has been proposed (JP-A-55-131958).

[0005]

However, the resealing method in which the current-carrying terminals are pulled out has the following disadvantages. 1. The current-carrying terminal needs to have a length of at least 2 to 3 mm or more. 2. Since the current-carrying terminals are exposed and exposed to air, corrosion progresses over time, causing breakage or rusting, so that rust must be removed before applying voltage. Yes, reopened in large quantities (recycle)
It takes time and effort to do.

[0006] 3. For parts used in electronic equipment,
If the current-carrying terminals are exposed from a part of this part, there is a chance of contact with other parts at the time of assembling or the like, which causes trouble. 4. It is necessary to secure an extra length for the resistance heating element for the current-carrying terminal, which causes an increase in manufacturing cost.

The present invention relates to a method for resealing a resin case welded using a resistance heating element, wherein the problems described in the above items 1 to 4 are solved and the resealing method is applied to the method. It is an object of the present invention to provide a resin case member.

[0008]

The resealable method of the resin case according to the present invention and the structure of the resin case member to which the resealable method is applied are as follows.

1. When heat-welding a resin case member made of thermoplastic resin, a resistance heating element is sandwiched between its joint surfaces,
In a resin case bonded and sealed by applying a voltage to the resistance heating element to generate heat by melting the resin on the joining surface, then stopping the heat generation and curing the resin case member to weld the resin, When re-sealing the case, a through hole is opened in the resin case wall near the resistance heating element installation with a heating rod to expose the resistance heating element in the through hole, and then a voltage application terminal is connected to the through hole. A method in which a voltage is applied while being inserted and brought into contact with a resistance heating element, thereby causing the resistance heating element to generate heat and melting the resin on the joint surface, thereby resealing the sealed resin case.

[0010] 2. When the resin case is opened in the resin case bonded and sealed by the welding method described in 1 above,
Using a heating chip having a heating means for instantaneously generating heat and a cooling means for instantaneously cooling, a through hole is opened in the resin case wall near the resistance heating element installation, and the resistance heating element is exposed in the through hole. Then, by inserting a voltage application terminal into the through hole and applying a voltage while making contact with the resistance heating element, the resistance heating element is heated to melt the resin on the bonding surface, thereby being sealed. 2. The method for resealing a sealed resin case according to the item 1, wherein the resin case is resealed.

3. When heat-welding a resin case member made of thermoplastic resin, a resistance heating element is sandwiched between its joint surfaces,
In a resin case bonded and sealed by applying a voltage to the resistance heating element to generate heat by melting the resin on the joining surface, then stopping the heat generation and curing the resin case member to weld the resin, A thin portion is formed integrally with a part of the resin case member near the installation of the resistance heating element, and a through-hole can be formed in the thin portion before molding the case. A resin case member.

4. When heat-welding a resin case member made of thermoplastic resin, a resistance heating element is sandwiched between its joint surfaces,
In a resin case bonded and sealed by applying a voltage to the resistance heating element to generate heat by melting the resin on the joining surface, then stopping the heat generation and curing the resin case member to weld the resin, By forming a through hole integrally with a part of the wall surface of the resin case member in the vicinity of the installation of the resistance heating element before molding the case, the voltage application terminal can be inserted using the through hole. A resin case member formed of a thermoplastic resin, wherein the case member is made of a thermoplastic resin.

5. When heat-welding a resin case member made of thermoplastic resin, a resistance heating element is sandwiched between its joint surfaces,
In a resin case bonded and sealed by applying a voltage to the resistance heating element to generate heat by melting the resin on the joining surface, then stopping the heat generation and curing the resin case member to weld the resin, At the time of molding the case, a through hole is formed integrally with a part of the wall surface of the resin case member in the vicinity of the resistance heating element, and the through hole is closed with a sealing member or a sticking member. A resin case member, wherein the sealing member or the adhesive member is removed to open a through hole, and a voltage application terminal can be inserted into the hole.

[0014]

When the resin case is fused, a resistance heating element is sandwiched between the joint surface of the case body and the cover, and a voltage application terminal (electrode) is provided in a previously formed voltage application hole.
By applying a voltage to the resistance heating element to generate heat, the resin on the joining surface is melted and fused, and in this state, the application of the voltage is stopped and the melted and fused resin is cured, so that the case body and the cover are hardened. Join. In this resin case, if a voltage is applied to the resistance heating element again, the cured resin is melted again. At this time, the case can be easily resealed without any force by acting on the case body and the cover in the detaching direction.

When a voltage is applied to the resistance heating element again, the voltage application hole is used, or a through-hole is separately formed for reapplication, and a voltage application terminal is inserted into the hole to apply the voltage. By doing so, the resistance heating element can generate heat. The through hole can be opened using a hot rod or a heating chip on the resin case wall near the resistance heating element. However, in a member in which a through hole for inserting a voltage application terminal is previously formed integrally at the time of molding the case, it is also possible to apply a voltage using this hole.

[0016]

In the case of the first aspect, two through-holes are opened with a hot rod on the wall surface of a resin case near a position where a resistance heating element is installed, and a part of the resistance heating element is exposed. Next, a voltage application terminal is inserted into the two through holes and brought into contact with the resistance heating element, and a voltage is applied to generate heat, thereby melting the resin on the bonding surface.

In the case of claim 2, the heating chip is brought into contact with the wall surface of the resin case near the position where the resistance heating element is installed, and the heating element of the heating chip is heated by applying a voltage, and further pressed against the wall surface. Is melted to form a through-hole, and then the application of voltage is stopped, and a cooling medium is sprayed on the heating element to return the temperature to room temperature, thereby curing the resin around the through-hole.
As a result, a through hole having the same diameter as the heating chip can be formed. By opening two through holes to expose a part of the resistance heating element, a voltage application terminal is inserted into the two through holes and brought into contact with the resistance heating element to apply a voltage to the resistance heating element. The heating element generates heat to melt the resin on the bonding surface.

In the case of the third aspect, when the case member is molded, a thin portion is formed integrally with the wall surface of the resin case member in the vicinity of the position where the resistance heating element is installed, so that the heating rod or the heating chip is formed. This facilitates the formation of the through-holes by using.

In the case of the fourth aspect, a through-hole for voltage application is formed integrally with the wall surface of the resin case near the position where the resistance heating element is installed at the time of molding, thereby facilitating insertion of the voltage application terminal. Things. In addition, this through-hole may be a hole formed for performing fusion bonding, or may be formed separately therefrom.

In the case of claim 5, a through-hole for applying a voltage is formed integrally with the wall surface of the resin case near the position where the resistance heating element is installed at the time of molding, and the through-hole for applying a voltage is usually closed or closed. The sealing member is sealed, but when the case is reopened, the sealing member or the sticking member is removed so that the voltage application terminal can be inserted.

Examples of the thermoplastic resin which is the material of the resin case according to the present invention include, for example, polyethylene, polypropylene, polystyrene, AS resin, ABS resin, methacryl, polyvinyl chloride, polycarbonate and the like.

An embodiment of the present invention will be described with reference to the drawings. Note that electronic components incorporated in the battery case are omitted for simplification of the drawing.

FIG. 1 is a perspective view of a battery case 10 used in an embodiment of the present invention. The method of welding the battery case 10 is shown in FIG.
As shown in FIG. 2, the resistance heating element 20 is sandwiched between the joining surfaces of the case body 11 and the cover 12, and a voltage is applied to both ends 20 a and 20 b of the resistance heating element 20 that has come out of the battery case 10 to generate heat. The resin on the bonding surface is melted by heat. Thereafter, when the application of the voltage is stopped, the melted resin is hardened, and the case body 11 and the cover 12 are joined. Both ends of the resistance heating element 20 that has come out of the case are cut off at the wall surface of the battery case 10 and removed.

Next, when the battery case 10 is resealed, it is necessary to heat the resistance heating element 20 again to melt the resin on the joint surface. Therefore, first, an embodiment in which two through holes 13 for inserting a voltage application terminal 30 for applying a voltage to the resistance heating element 20 in the battery case 10 are introduced will be introduced.

FIG. 2 shows an opening 14 for opening the through hole 13 in the case wall near the installation of the resistance heating element 20. FIG. 2 is a plan view showing a state in which the resistance heating element 20 is installed on the case main body 11, and is originally covered with the cover 12.

[0026]

Embodiment 1 Embodiment 1 corresponds to the first aspect of the present invention, and FIG. 3 is a view in which a through hole 13 is opened using a hot rod 40.
FIG. 4 is a cross-sectional view taken along the line AA (opening 14) of FIG.
It is sectional drawing of the BB part of FIG. In FIG. 3, the inside portion of the opening portion 14 in contact with the heating rod 40 does not have the fitting recess 15 for welding shown in FIG. 4, and a space is formed between the inner wall surface 16 and the resistance heating element 20. This is effective as the resin reservoir 17 for releasing the molten resin pushed into the inside of the case when the hot rod 40 penetrates the case wall surface. In addition, it is convenient to form a mark indicating the contact position of the hot rod 40 integrally with the opening 14 of the case wall.

It is desirable that the place where the heating rod 40 comes into contact is located near both ends of the internally provided resistance heating element 20. Hot rod 4
The method 0 includes a method of transferring heat from another heat source, a method of winding an electric heating wire such as a nichrome wire around a heating rod and heating the same, and the temperature may be raised to around the melting temperature of the thermoplastic resin constituting the battery case 10.

FIG. 3A shows a state in which the hot rod 40 is brought into contact with the opening 14 in the battery case to melt the resin, and FIG. 3B shows a state in which the press-through hole 13 is further formed. FIG. 3 (C) shows a state of the through hole 13 which is opened. Through holes are similarly formed in other openings by the above-described method.

[0029]

Embodiment 2 Embodiment 2 corresponds to the invention of claim 2 and has a heating chip 50 capable of instantaneous heating and instantaneous cooling.
This is an embodiment in which the through-hole 13 is opened by using. Before that, the configuration of the heating chip 50 will be described with reference to FIG.
FIG. 9A is an exploded perspective view of a main part of the heating chip 50, and FIG.
9B is a completed perspective view of the heating chip 50, and FIG. 9C is a cross-sectional view of the completed heating chip 50.

The heating element 51 used for the heating chip 50 of the present embodiment is made of metal having a diameter of 2 mm, has a cylindrical shape, and has a diameter at the contact surface 52 from about one third of the entire length in the axial direction. It has an inclined surface 53 so as to be 1.3 mm. The heating chip 5 is applied to the resin melted by the inclined surface 53.
Although it is easy to push 0, if there is no problem, the inclined surface 53 may be omitted.

The heating chip 50 includes a battery case 10
A pair of electric wires 54 at the other end remote from the contact surface 52
Are electrically connected by welding or the like. Further, a tip of a pipe 55 for blowing a cooling medium into the heating element 51 is inserted into the other end portion side of the heating element 51, and after the cooling of the heating element 51 by being injected from the pipe 55. The slit 56 for allowing the cooling medium to escape to the outside is provided with the heating element 5.
Two portions are provided so as to face one side surface.

The number of the slits 56 is not limited to two, and the shape and number of the slits 56 can be freely determined as needed.
The insulating tube 57 serves to fix the electric wires 54 and the pipe 55 in a predetermined positional relationship with respect to the heating element 51,
External pressure applied to 1 is prevented.

In this embodiment, the cover 58 is made of, for example, a heat-resistant synthetic resin, and covers and fixes a part of the exposed portion of each wire 54 in a sealed state. The case body 1
The inside of the opening 14 is the resin reservoir 1 shown in the first embodiment.
It is desirable to form it in such a shape as to be 7.

As a method for opening the through hole 13, first, the heating chip 50 is brought into contact with the opening 14 on the case wall as shown in FIG. 5A, and then a voltage is applied to the electric wire 54. In this embodiment, a transformer for supplying power to the electric wire 54 has a capacity of 180 VA, and AC4V is applied to the heating element. The application time is 1.2 seconds, and the heating element 51 is instantaneously heated. Then, the voltage application is stopped and the heating element 5 is heated for 2 seconds.
When the entire 1 reaches the melting temperature of the resin, the resin in the opening 14 melts.

Further, as shown in FIG. 5B, when the heating chip 50 is pushed in, the through hole 13 is opened. When a predetermined insertion value is obtained, compressed air is blown from the pipe 55 to the heating element 51, and the heating element 51 is immediately cooled and returned to room temperature. After the compressed air is blown onto the heating element 51, it escapes to the outside through the slit 56 formed in the heating element 51, so that forced cooling can be efficiently performed.

In FIG. 5D, after the heating element 51 penetrates through the opening 14, compressed air for cooling is supplied to the heating element 51 by a pipe 55.
A state in which the air is further sprayed and discharged from the slit 56 to the outside is shown as a cross-sectional view.

Therefore, the resin around the melted opening is hardened in that state, and the through-hole 13 having a constant diameter is reliably formed. FIG. 5C shows the state of the through-hole 13 that has been opened. The through hole 13 is similarly opened in the other opening 14 by the method described above.

[0038]

Third Embodiment The third embodiment corresponds to the third aspect of the present invention. In the first and second embodiments, the through hole 13 is formed by using the heating rod 40 or the heating tip 50. If the thin portion 60 is formed thinner than the other case wall surfaces, the thickness of the opening portion 14 of the case wall surface contacting the heating rod 40 or the heating chip 50 can be easily formed when the through hole 13 is opened. It is also possible to pierce and open the thin portion with a tool having a tip.

In this embodiment, as shown in FIG. 6, a thin portion 60 having a thickness of 0.3 mm is provided at two places of the opening 14 in FIG.
Was integrally formed at the time of molding. The method of forming the thin portion 60 is to make the cavity portion of the molding die thin, or to provide a movable portion in the cavity portion, fill the resin, and then advance the movable portion into the cavity to form the thin portion 60. And so on.

The opening time of the through hole 13 by the heating rod 40 or the heating tip 50 by the thin portion 60 according to the present embodiment can be performed in a much shorter time than in the case of the first and second embodiments. It is possible.

[0041]

[Embodiment 4] This embodiment corresponds to the invention of claim 4, in which through holes 13 for the voltage application terminals 30 are integrally formed at two openings 14 in FIG. FIG. 7 shows this state.

In this embodiment, the diameter of the voltage application terminal 30 is 1
mm, the diameter of the through hole 13 was set to 1.5 mm.
If there is no discomfort in appearance and there is no need to seal,
If the through holes 13 are formed in advance, the battery case 10 can be easily opened.

[0043]

[Embodiment 5] This embodiment corresponds to the invention of claim 5 and is a case where it is necessary to close the through hole 13 integrally formed in advance at the time of molding the case. The method is shown in FIG.
As shown in FIG.
As shown in FIG. 8B, a case body 11 member in which a sticking member 80 such as a seal is stuck to the through hole 13 and closed is used.

Next, the voltage application terminal 30 is inserted into the two through holes 13 formed in the opening 14 of the battery case 10 according to the first to fifth embodiments, and is brought into contact with the resistance heating element 20 so that the resistance heating element 20 is contacted. By generating heat in the battery case 1, the battery case 1
An example of reopening 0 will be introduced.

[0045]

[Embodiment 6] FIGS. 10 to 13 show that the vacuum pad is sucked and held on the bottom surface of the case main body and the top surface of the cover in the battery case 10, and a voltage is applied to the resistance heating element 20 to reseal the battery case 10. This is an embodiment of the present invention. FIG. 10 is a plan view in which the battery case 10 to be opened is placed on the receiving stand 90. 11 to 13 are cross-sectional views taken along the line CC in FIG. 10, and an embodiment will be described based on this cross-sectional view.

First, the receiving table 90 will be described with reference to FIG. In the receiving stand 90, the surface on which the battery case 10 is installed has a concave portion 91 having the same shape as the bottom surface of the battery case 10, and a vacuum for adsorbing and holding the bottom surface of the battery case 10 at the center of the concave portion 91. A pad A92 is provided, and the vacuum pad A92 is connected to an air vacuum device (not shown) through an internal pipe 93.

On the top surface of the cradle 90, two guide posts 94 are erected so as to sandwich the battery case 10, and a sliding plate 95 extending between the two guide posts 94 slides vertically. The guide plate 94 is biased upward by a spring 96 between the sliding plate 95 and the top surface of the receiving table 90.

At the upper end of the guide post 94, a stopper 97 is provided which is detachable so that the slide plate 95 does not come off the guide post 94. The battery case 10 is attached to the tip of the sliding plate 95.
A pipe 99 having a vacuum pad B98 attached to the top surface of the pipe 99 is fixed, and the other end of the pipe 99 is connected to the air vacuum device.

FIG. 12 is a diagram in which a voltage is applied to the resistance heating element 20 built in the battery case 10 to melt the resin on the joint surface. First, when the air vacuum device is set to the suction operation, the vacuum pad A92 is attracted to the bottom surface of the battery case 10 and is brought into close contact with the concave portion 91 of the receiving base 90. Next, since the vacuum pad B98 is also in the suction state, when the sliding plate 95 is lowered, the vacuum pad B98 is suctioned to the top surface of the battery case 10. At this time, the suction force of the vacuum pad A92 and the suction force of the vacuum pad B98 are adjusted more strongly than the suction force of the vacuum pad A92, so that the battery case 10 keeps the close contact with the concave portion 91 of the receiving base 90.

In the above state, the voltage application terminals 30 are inserted into the two through holes 13 formed in the opening 14 on the case wall surface of the battery case 10 to make contact with the resistance heating element 20 to apply a voltage. The resin on the joint surface is melted. The voltage application condition in the example was to apply AC 8 V for about 3 seconds using a 180 VA transformer.

When the resin on the joint surface is sufficiently melted, a force acts on the case body 11 and the cover 12 in the detaching direction, so that the cover 12 is moved from the case body 11 by the action of the spring 96 passed through the guide support 94. Separated, sliding plate 95
Together with the battery case 10, and the battery case 10 is opened. FIG. 13 shows the opened state.

As described above, by using the method of resealing the resin case by applying a voltage to the built-in resistance heating element according to the present invention, it is possible to safely re-open the resin case without affecting the built-in electronic parts and the like in a short time. Opening work can be performed.

In some cases, there is a cut surface of the resistance heating element at the end face of the case. However, it is inappropriate to apply a voltage due to its small cross-sectional area, and the surface is often eroded. Voltage cannot be applied. Further, in this embodiment, the battery case is held by using the vacuum pad, but another method capable of holding the battery case may be used.

[0054]

As described above, according to the present invention, when the thermoplastic resin case welded with the resistance heating element sandwiched therebetween is resealed, the wall of the resin case near the installation of the resistance heating element is heated with a hot rod or a heating chip. A through-hole is formed, or a through-hole is integrally formed on the wall surface of the resin case at the time of molding, and a voltage application terminal is inserted through the through-hole to apply a voltage to the resistance heating element inside the resin case to generate heat. It is characterized by melting the resin on the joint surface and resealing the resin case.
By using this method, the following effects can be obtained.

1. Since the energizing terminals are not exposed from the resin case, they do not hinder the assembly of components. 2. Since a voltage is applied from a newly opened through-hole, the voltage can be reliably applied without the corrosion of the resistance heating element. 3. Since the current-carrying terminals and the like are not exposed outside the case, no trouble occurs with other components.

4. Since the current-carrying terminals are not drawn out, the resistance heating element can be shortened, and the cost can be reduced. 5. Since the resin case can be easily resealed, it is effective when the resin case and the internal components are separated and discarded, or when the internal components are recycled.

[Brief description of the drawings]

FIG. 1 is a perspective view of a battery case used in the present embodiment.

FIG. 2 is a plan view illustrating an installation state of a case body and a resistance heating element.

FIG. 3 is a sectional view taken along the line AA in which a through hole is formed in the opening in FIG. 2 with a hot rod.

FIG. 4 is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is a cross-sectional view taken along the line AA of FIG. 2, in which a through hole is formed in the opening with a heating chip.

FIG. 6 is an AA in which a thin portion is formed in an opening in FIG. 2;
Part sectional drawing.

FIG. 7 is a view showing a structure in which a through hole is formed in advance in the opening in FIG. 2;
FIG.

FIG. 8 is a cross-sectional view taken along the line AA in FIG. 2 in which the through-hole is sealed with a sealing member or a sticking member.

9A and 9B show an essential part of the heating chip, wherein FIG. 9A is an exploded view, FIG. 9B is a completed perspective view, and FIG. 9C is a sectional view.

FIG. 10 is a plan view in which a battery case is placed on a receiving stand.

FIG. 11 is a cross-sectional view taken along the line CC in FIG. 10 in which the battery case is placed on a receiving stand.

FIG. 12 is a cross-sectional view taken along the line CC in FIG. 10 showing a state in which a voltage application terminal is brought into contact with a resistance heating element in a battery case.

FIG. 13 is a cross-sectional view taken along the line CC in FIG. 10 showing a state in which the cover of the battery case is detached from the case main body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Battery case 11 Case main body 12 Cover 13 Through-hole 14 Opening 20 Resistance heating element 30 Voltage application terminal 40 Heating rod 50 Heating chip 51 Heating element 54 Electric wire 55 Pipe 56 Slit 60 Thin part 70 Sealing body 80 Attaching member 90 Receiving stand 92 Vacuum pad A 94 Guide post 95 Sliding plate 96 Spring 98 Vacuum pad B

Claims (5)

[Claims] When a resin case member made of a thermoplastic resin is heat-welded, a resistance heating element is sandwiched between bonding surfaces thereof, a voltage is applied to the resistance heating element to generate heat, and the resin on the bonding surface is melted. After the heat is stopped and cured, the resin case is joined and sealed by welding the resin case member. When the resin case is reopened, a hot rod is used to close the resin case near the resistance heating element. A through hole is opened in the wall surface to expose the resistance heating element in the through hole, and then a voltage application terminal is inserted into the through hole to apply a voltage while contacting the resistance heating element, thereby forming the resistance heating element. A method of resealing a sealed resin case by causing the body to generate heat and melting the resin on the joint surface. 2. A resin case joined and sealed by the welding method according to claim 1, wherein when the resin case is opened,
Using a heating chip having a heating means for instantaneously generating heat and a cooling means for instantaneously cooling, a through hole is opened in the resin case wall near the resistance heating element installation, and the resistance heating element is exposed in the through hole. Then, by inserting a voltage application terminal into the through hole and applying a voltage while making contact with the resistance heating element, the resistance heating element is heated to melt the resin on the bonding surface, thereby being sealed. The method for resealing a sealed resin case according to claim 1, wherein the sealed resin case is resealed. 3. When a resin case member made of a thermoplastic resin is heat-welded, a resistance heating element is sandwiched between joining surfaces thereof, a voltage is applied to the resistance heating element to generate heat, and the resin on the joining surface is melted. Thereafter, in a resin case joined and sealed by a method in which the heat generation is stopped and the resin case member is welded by being cured, a part of the resin case member near the installation of the resistance heating element is previously formed at the time of molding the resin case. A resin case member characterized in that a thin portion is formed integrally with the case member so that a through hole can be opened in the thin portion. 4. When a resin case member made of a thermoplastic resin is thermally welded, a resistance heating element is sandwiched between joining surfaces thereof, a voltage is applied to the resistance heating element to generate heat, and the resin on the joining surface is melted. Thereafter, the resin case is joined and sealed by welding the resin case member by stopping the heat generation and curing the resin case member. A resin case member formed of a thermoplastic resin, characterized in that a through-hole is integrally formed in the portion so that a voltage application terminal can be inserted using the through-hole. . 5. When a resin case member made of a thermoplastic resin is heat-welded, a resistance heating element is sandwiched between joining surfaces thereof, a voltage is applied to the resistance heating element to generate heat, and the resin on the joining surface is melted. Then, in the resin case joined and sealed by a method in which the heat generation is stopped and the resin case member is welded by being cured, when the resin case is molded, the wall surface of the resin case member near the installation of the resistance heating element is previously set. A through-hole is formed integrally in a part, this through-hole is sealed with a sealing member or a sticking member, and at the time of resealing, the sealing member or the sticking member is removed to open the through-hole. A resin case member configured to allow an application terminal to be inserted therein.