JP2018149751A - Method for heat welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for heat welding capable of reducing deterioration of sealing performance of an airtight container.SOLUTION: Resistive heating elements 13A and 13B having in each element: semi-circular shaped circular-shape formation parts 41A and 41B; power receiving parts 42A and 42B connected to the circular-shape formation parts 41A and 41B, respectively; and a connecting part 43 for connecting the circular-shape formation part 41A and the circular-shape formation part 41B to each other, are arranged between each of joint surfaces of an upper case member 11 and a lower case member 12 allowing the power receiving parts 42A and 42B and the connecting part 43 in each element come alongside such as to form circular shape parts 46A and 46B. When the circular-shape formation parts 41A and 41B are in an unlocked state in the direction parallel to the joint surfaces, the resistive heating elements 13A and 13B are energized. Heat generation of the resistive heating elements 13A and 13B causes welding of the upper case member 11 and the lower case member 12 to form an airtight container.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heat welding method for welding molded articles made of a thermoplastic resin.

  A technique is known in which a resistance heating element is sandwiched between molded articles made of a thermoplastic resin, the resistance heating element is energized, and the molded articles are welded together by the heat generated by the resistance heating element to form a sealed container.

  For example, in Patent Document 1, sealing is performed using first and second resistance heating elements capable of annularly welding joint portions between molded products (case members) by arranging and arranging power receiving portions set at both ends. Techniques for forming containers are disclosed.

  In the technique of Patent Document 1, a groove portion is formed over the entire circumference of the peripheral wall portion of the first case member. In the groove portion of the first case member, the first and second resistance heating elements are arranged over the entire circumference. Here, the groove portion of the first case member includes an annular groove and a branch groove that branches from the annular groove and extends linearly. In the first and second resistance heating elements, the main body portion forming an annular shape is disposed in the annular groove. On the other hand, the power receiving units of the first and second resistance heating elements are bundled and arranged in the branch groove.

  A fitting projection is formed on the peripheral wall of the second case member. The fitting protrusion of the second case member is fitted into the groove so as to sandwich the first and second resistance heating elements between the groove of the first case member. In this state, the first and second resistance heating elements are energized, and the groove portion of the first case member and the fitting protrusion of the second case member are welded to form a sealed container.

JP 2013-208883 A

  However, in the technique of Patent Document 1, the entirety of the first and second resistance heating elements is constrained by the groove by arranging the entirety of the first and second resistance heating elements in the groove. For this reason, tension is applied at various locations of the first and second resistance heating elements, and as a result, forces in directions away from each other may be applied to the two bundled power receiving units.

  As a result, the first and second case members are welded while the interval between the bundled power reception units is widened, and there is a possibility that a cavity may be formed between the bundled power reception units. As a result, the airtightness of the airtight container formed may be impaired.

  This invention is made | formed in view of the above, and it aims at providing the heat welding method which can suppress that the sealing performance of an airtight container is impaired.

  In order to achieve the above object, the first feature of the thermal welding method according to the present invention is that the first and second resistors each have a semi-annular annular forming portion and a plurality of bundle portions connected to the annular forming portion. A heating element is disposed between the respective joint surfaces of the first and second molded articles made of thermoplastic resin along the bundling portion so that the annular portion is formed by the annular forming portion. In the state where the annular forming portion is unconstrained in the direction parallel to the joint surface, the first and second resistance heating elements are energized, and the first molding is performed by the heat generation of the first and second resistance heating elements. And sealing the product and the second molded product to form a sealed container.

  A second feature of the heat welding method according to the present invention is that the first and second resistance heating elements each have a plurality of the annular forming portions connected via the bundle portions, and the bundle portions of each other. Are formed to form a plurality of the annular portions, and the first and second molded products are welded to each other to form a plurality of sealed spaces. In the region where the bundle portion is arranged, at least one of the first and second molded products is formed with an exhaust hole that communicates the joint surface with the outside, and the bundle portion between the annular portions The resin of the first and second molded products vaporized by the heat generation is discharged from the exhaust hole.

  A third feature of the thermal welding method according to the present invention is that, in the region where the bundled portions between the annular portions are arranged, at least one of the first and second molded products has the joining surface formed in the annular shape. The taper surface is such that the distance from the bundle part increases toward the end from the center of the bundle part in the extending direction of the bundle part between the parts, and the joint surface sandwiching the bundle part between the annular parts The melting is to proceed from the center in the extending direction of the bundle portion toward both ends.

  According to the first feature of the heat welding method according to the present invention, the first and second resistance heating elements are energized in a state where the annular forming portion is unconstrained in the direction parallel to the joint surface. The first molded product and the second molded product are welded by the heat generated by the two-resistance heating element. For this reason, it is suppressed that a non-uniform tension is applied to each part of an annular formation part. Thereby, the 1st molded product and the 2nd molded product can be welded in the state where the position of the bundle part of the 1st and 2nd resistance heating element was stabilized. For this reason, it is possible to prevent the bundling portions of the first and second resistance heating elements that are along each other from being separated from each other during welding. Therefore, it is possible to reduce the formation of a cavity between the bundle portions of the first and second resistance heating elements. As a result, it can suppress that the airtightness of an airtight container is impaired.

  According to the second feature of the heat welding method according to the present invention, since the resin of the first and second molded products vaporized by the heat generation of the bundle portion between the annular portions is discharged from the exhaust hole, the bundle portion The formation of cavities around the periphery of the As a result, it can suppress more that the airtightness of an airtight container is impaired.

  According to the 3rd characteristic of the heat welding method which concerns on this invention, in the area | region where the bundling part between annular parts is arrange | positioned, at least any one joint surface of a 1st and 2nd molded product is between annular parts. The taper surface has a larger distance from the bundle part toward the end from the center of the bundle part in the extending direction of the bundle part, and the melting of the joint surface sandwiching the bundle part between the annular parts is Proceed from the center toward both ends. As a result, the molten resin fills the gap around the bundling portion and the melting of the joining surface proceeds, so that the formation of cavities around the bundling portion can be suppressed. As a result, it can suppress more that the airtightness of an airtight container is impaired.

It is a perspective view of the airtight container formed by the heat welding method which concerns on 1st Embodiment. It is an assembly perspective view of the airtight container shown in FIG. It is a perspective view from the bottom face side of the upper case member for forming the airtight container shown in FIG. (A) is a front view of the upper case member for forming the airtight container shown in FIG. (B) is a bottom view of the upper case member. (A) is a front view of the lower case member for forming the airtight container shown in FIG. (B) is a top view of a lower case member. It is a top view of the resistance heating element for forming the airtight container shown in FIG. It is a figure which shows the state which pinched | interposed the resistance heating element between the upper case member and lower case member in 1st Embodiment. FIG. 8 is a partially enlarged cross-sectional view taken along line AA in FIG. 7. FIG. 8 is a partial enlarged cross-sectional view taken along line BB in FIG. 7. It is a partial expanded sectional view along CC line of FIG. It is a figure which shows the mode of welding with the upper case member and lower case member in the connection part vicinity of a resistance heating element. It is a figure which shows the mode of welding with the upper case member and lower case member in the annular formation part vicinity of a resistance heating element. It is a top view in the state where a resistance heating element was inserted between an upper case member and a lower case member in a 2nd embodiment. FIG. 14 is a partial enlarged cross-sectional view taken along the line DD in FIG. 13. It is a partial expanded sectional view along the EE line of FIG. It is the elements on larger scale in the cut surface similar to FIG. 14 in the state which pinched | interposed the resistance heating element between the upper case member and the lower case member in 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

  The following embodiments exemplify devices for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, arrangement, etc. of each component. Is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

(First embodiment)
FIG. 1 is a perspective view of a sealed container formed by the heat welding method according to the first embodiment of the present invention. 2 is an assembled perspective view of the sealed container shown in FIG. FIG. 3 is a perspective view from the bottom side of the upper case member for forming the sealed container shown in FIG. 1. FIG. 4A is a front view of the upper case member. FIG. 4B is a bottom view of the upper case member. Fig.5 (a) is a front view of the lower case member for forming the airtight container shown in FIG. FIG. 5B is a plan view of the lower case member. FIG. 6 is a plan view of a resistance heating element for forming the sealed container shown in FIG. In the following description, the vertical and horizontal directions indicated by the arrows in FIG.

  As shown in FIG. 1, the sealed container 1 has two sealed chambers 2A and 2B that each form a sealed space. In some cases, the alphabetical suffixes in the reference numerals of the sealed chambers 2A, 2B, etc. are omitted and collectively described.

  As shown in FIG. 2, the sealed container 1 is formed by welding an upper case member 11 and a lower case member 12 using resistance heating elements 13A and 13B.

  The upper case member 11 and the lower case member 12 are made of a thermoplastic resin. Examples of the thermoplastic resin used for the upper case member 11 and the lower case member 12 include ABS resin, acetal resin, acetal copolymer, and acrylic resin. The upper case member 11 and the lower case member 12 correspond to the first molded product or the second molded product in the claims, respectively.

  The upper case member 11 has container parts 21A and 21B. The container portions 21A and 21B are combined with lid portions 31A and 31B of the lower case member 12 to be described later to form sealed chambers 2A and 2B. The container parts 21A and 21B each have a hollow rectangular parallelepiped shape, and the lower side is opened.

  A flange 22 is attached to the container portions 21A and 21B. The flange 22 is installed so that it may go around the lower end vicinity of container part 21A, 21B. The container parts 21 </ b> A and 21 </ b> B are connected via a flange 22. The lower surface 22 a of the flange 22 forms a part of the joint surface 23 of the upper case member 11. Power feeding portions 24A and 24B are attached to the flange 22.

  The power feeding portion 24 </ b> A is formed so that a part thereof protrudes to the left from the left end side of the flange 22. The power feeding unit 24 </ b> B is formed so that a part thereof protrudes from the right end side of the flange 22 to the right side. The power feeding unit 24A and the power feeding unit 24B have the same shape, and are installed so as to be horizontally reversed.

  Grooves 25 are formed in the power feeding units 24A and 24B. A power receiving portion 42A of resistance heating elements 13A and 13B, which will be described later, is disposed in the groove 25 of the power feeding portion 24A. A power receiving unit 42B of resistance heating elements 13A and 13B, which will be described later, is disposed in the groove 25 of the power feeding unit 24B.

  The bottom surface 25 a of the groove 25 forms a part of the joint surface 23 of the upper case member 11. The bottom surface 25 a of the groove 25 of the power feeding unit 24 </ b> A and the bottom surface 25 a of the groove 25 of the power feeding unit 24 </ b> B are connected to the lower surface 22 a of the flange 22. At the left end of the bottom surface 25a of the groove 25 of the power feeding unit 24A and the right end of the bottom surface 25a of the groove 25 of the power feeding unit 24B, a power feeding port 26 for exposing power receiving units 42A and 42B of the resistance heating element 13 described later is formed. Has been.

  A pair of restraining walls 27 </ b> A and 27 </ b> B are erected between the container portions 21 </ b> A and 21 </ b> B of the flange 22. A connecting portion 43 of resistance heating elements 13A and 13B, which will be described later, is disposed between the restraining walls 27A and 27B. The restraining walls 27A and 27B restrain the two connecting portions 43 that are arranged so as to be along each other.

  The lower case member 12 has lid portions 31A and 31B. The lid portions 31A and 31B are combined with the container portions 21A and 21B of the upper case member 11 to form sealed chambers 2A and 2B, respectively. Each of the lid portions 31A and 31B has a hollow rectangular parallelepiped shape, and the upper side is opened.

  A peripheral wall portion 32 is attached to the lid portions 31A and 31B. The peripheral wall portion 32 is installed so as to go around the upper end portions of the lid portions 31A and 31B. The lid portions 31 </ b> A and 31 </ b> B are connected via the peripheral wall portion 32. The upper surface of the peripheral wall portion 32 is a joint surface 33 of the lower case member 12.

  Grooves 34 </ b> A and 35 </ b> A into which the right end portion of the power feeding portion 24 </ b> A of the upper case member 11 is fitted are formed on the peripheral wall portion 32 on the left side of the lid portion 31 </ b> A. A convex portion 36A that fits into the groove 25 of the power feeding portion 24A of the upper case member 11 is formed between the grooves 34A and 35A. And in the surrounding wall part 32, the electric power feeding port 37A for exposing the power receiving part 42A of the resistance heating body 13 mentioned later is formed in the left side of the convex part 36A.

  Further, grooves 34B and 35B in which the left end portion of the power feeding portion 24B of the upper case member 11 is fitted are formed in the peripheral wall portion 32 on the right side of the lid portion 31B. A convex portion 36B that fits into the groove 25 of the power feeding portion 24B of the upper case member 11 is formed between the grooves 34B and 35B. And in the surrounding wall part 32, the electric power feeding port 37B for exposing the power receiving part 42B of the resistance heating element 13 mentioned later is formed in the right side of the convex part 36B.

  Further, grooves 38A and 38B into which the restraining walls 27A and 27B of the upper case member 11 are respectively fitted are formed in the peripheral wall portion 32 at a portion between the lid portion 31A and the lid portion 31B.

  The resistance heating elements 13A and 13B are made of a linear metal that generates heat when energized. The resistance heating elements 13A and 13B correspond to a first resistance heating element or a second resistance heating element, respectively.

  As shown in FIG. 6, the resistance heating element 13 includes semi-annular annular forming portions 41A and 41B, linear power receiving portions 42A and 42B connected to the annular forming portions 41A and 41B, and an annular forming portion 41A. And a linear connecting portion 43 that connects the annular forming portion 41B. The power receiving units 42A and 42B and the connecting unit 43 correspond to a bundled unit in the claims.

  The resistance heating elements 13A and 13B are arranged between the joint surface 23 of the upper case member 11 and the joint surface 33 of the lower case member 12 so that the power receiving portions 42A and 42B and the connection portion 43 are aligned with each other. Be placed. At this time, the power receiving portions 42A of the resistance heating elements 13A and 13B are bundled and arranged in the groove 25 of the power feeding portion 24A. Further, the power receiving portions 42B of the resistance heating elements 13A and 13B are bundled and arranged in the groove 25 of the power feeding portion 24B. Further, the connecting portions 43 of the resistance heating elements 13A and 13B are bundled and arranged between the restraining walls 27A and 27B.

  As shown in FIG. 2, an annular portion 46A is formed by the annular forming portions 41A of the resistance heating elements 13A and 13B. An annular portion 46B is formed by the annular forming portions 41B of the resistance heating elements 13A and 13B. The annular portions 46A and 46B are formed so as to surround the periphery of the container portions 21A and 21B, respectively.

  Next, a heat welding method for manufacturing the sealed container 1 will be described.

  First, as shown in FIG. 7, the resistance heating elements 13 </ b> A and 13 </ b> B are sandwiched between the joint surface 23 of the upper case member 11 and the joint surface 33 of the lower case member 12. At this time, the resistance heating elements 13A and 13B are arranged so that the power receiving parts 42A and 42B and the connecting part 43 are aligned with each other, and the annular parts 46A and 46B surround the container parts 21A and 21B, respectively. .

  A state in which the resistance heating elements 13A and 13B are sandwiched between the joint surface 23 of the upper case member 11 and the joint surface 33 of the lower case member 12 is shown in FIG. Moreover, the partial expanded sectional view along the AA line of FIG. 7, the partially expanded sectional view along the BB line, and the partially expanded sectional view along the CC line are respectively shown in FIGS. .

  In the state of FIG. 7, as shown in FIG. 8, the power receiving portions 42 </ b> A of the resistance heating elements 13 </ b> A and 13 </ b> B are bundled and arranged in the groove 25 of the power feeding portion 24 </ b> A of the upper case member 11. And the convex part 36A of the lower case member 12 is fitted in the groove 25 of the power feeding part 24A so that the power receiving part 42A is sandwiched between the bottom surface 25a of the groove 25 of the power feeding part 24A. The groove 25 of the power feeding unit 24A restrains the two power receiving units 42A arranged so as to be along each other.

  In the state of FIG. 7, similarly to the power reception unit 42 </ b> A, the power reception units 42 </ b> B of the resistance heating elements 13 </ b> A and 13 </ b> B are bundled and arranged in the groove 25 of the power supply unit 24 </ b> B of the upper case member 11. And the convex part 36B of the lower case member 12 is fitted in the groove 25 of the power feeding part 24B so as to sandwich the power receiving part 42B between the bottom surface 25a of the groove 25 of the power feeding part 24B. The groove 25 of the power feeding unit 24B restrains the two power receiving units 42B arranged so as to be along each other.

  In the state of FIG. 7, as shown in FIG. 9, the connecting portions 43 of the resistance heating elements 13 </ b> A and 13 </ b> B are bundled and disposed between the restraining walls 27 </ b> A and 27 </ b> B of the upper case member 11. Then, the restraining walls 27A and 27B are respectively fitted in the grooves 38A and 38B of the lower case member 12, and the joining surface 23 of the upper case member 11 and the joining surface 33 of the lower case member 12 are between the restraining walls 27A and 27B. A connecting portion 43 is sandwiched therebetween. The restraining walls 27A and 27B restrain the two connecting portions 43 arranged so as to be along each other.

  Further, in the state of FIG. 7, as shown in FIG. 10, the annular forming portion 41 </ b> A of the resistance heating element 13 </ b> A is sandwiched between the joint surface 23 of the upper case member 11 and the joint surface 33 of the lower case member 12. Yes. Here, there is no structure that restrains the annular forming portion 41A on the outer side (front side) of the annular forming portion 41A. Thereby, the annular forming portion 41A of the resistance heating element 13A is in an unconstrained state in a direction parallel to the joint surfaces 23 and 33.

  Similarly to the annular formation portion 41A of the resistance heating element 13A, the annular formation portion 41B of the resistance heating element 13A and the annular formation portions 41A and 41B of the resistance heating element 13B are also unconstrained in the direction parallel to the joint surfaces 23 and 33. It is in a state.

  In the state of FIG. 7 as described above, a power supply electrode (not shown) is inserted into one of the power supply ports 26 of the power supply units 24A and 24B and one of the power supply ports 37A and 37B, and a resistance heating element. The electrodes are in contact with the power receiving units 42A and 42B of 13A and 13B.

  The resistance heating elements 13A and 13B are energized through the electrodes while pressing the upper case member 11 against the lower case member 12. Thereby, the resistance heating elements 13A and 13B generate heat, and the resin around the resistance heating elements 13A and 13B is melted.

  Thus, for example, as shown in FIG. 11, the resin of the upper case member 11 and the lower case member 12 is melted around the connecting portion 43 of the resistance heating elements 13 </ b> A and 13 </ b> B to form the fusion portion 51. For example, as shown in FIG. 12, the resin of the upper case member 11 and the lower case member 12 melts around the annular forming portion 41A of the resistance heating element 13A to form the fusion portion 51.

  Thus, the resin around the resistance heating elements 13A and 13B is melted to form the fusion part 51, whereby the upper case member 11 and the lower case member 12 are welded to each other at the joint surfaces 23 and 33. Thereby, the sealed container 1 is formed.

  Here, as described above, in the upper case member 11 and the lower case member 12, there is no structure that restrains the annular portions 46A and 46B outside the annular portions 46A and 46B. On the other hand, on the inner side of the annular portions 46A and 46B, portions below the flange 22 of the container portions 21A and 21B of the upper case member 11 exist as inner walls. Thereby, in order to prevent the volume of the sealed chambers 2A and 2B from decreasing, the molten resin is prevented from flowing into the internal spaces (sealed spaces) of the sealed chambers 2A and 2B.

  As described above, in the heat welding method of the first embodiment, the resistance heating element 13A is formed in a state in which the annular forming portions 41A and 41B of the resistance heating elements 13A and 13B are unconstrained in the direction parallel to the joint surfaces 23 and 33. , 13B and the upper case member 11 and the lower case member 12 are welded.

  For this reason, uneven tension is suppressed from being applied to each part of the annular forming parts 41A and 41B. Thereby, the upper case member 11 and the lower case member 12 can be welded in a state where the positions of the power receiving portions 42A and 42B and the connecting portion 43 of the resistance heating elements 13A and 13B are stabilized. For this reason, it is possible to prevent the power receiving portions 42A, the power receiving portions 42B, and the connecting portions 43 of the resistance heating elements 13A and 13B that are along each other from being separated from each other during welding. Therefore, it is possible to reduce the generation of a cavity between the power receiving portions 42A of the resistance heating elements 13A and 13B, between the power receiving portions 42B, and between the connecting portions 43. As a result, it is possible to prevent the sealing performance of the sealed chambers 2A and 2B of the sealed container 1 from being impaired.

  Moreover, in 1st Embodiment, the part below the flange 22 of the container parts 21A and 21B of the upper case member 11 is arrange | positioned as an inner wall inside annular part 46A, 46B, and molten resin is sealed chamber 2A, Inflow to the internal space of 2B is suppressed. Thereby, it can prevent that the volume of sealed chamber 2A, 2B reduces by inflow of molten resin.

(Second Embodiment)
In the second embodiment, instead of the upper case member 11 of the first embodiment described above, an upper case member 11A in which an exhaust hole 61 is formed in the upper case member 11 is used. FIG. 13 is a plan view showing a state in which the upper case member 11 of FIG. 7 is replaced with the upper case member 11A. FIG. 14 is a partially enlarged cross-sectional view taken along the line DD of FIG. FIG. 15 is a partially enlarged cross-sectional view taken along the line EE of FIG.

  As shown in FIGS. 13 to 15, the upper case member 11 </ b> A is formed with an exhaust hole 61 that communicates the joint surface 23 with the outside in a region between the restraining walls 27 </ b> A and 27 </ b> B. That is, the exhaust hole 61 is formed in the upper case member 11A in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed.

  Here, since the two connecting portions 43 of the resistance heating elements 13A and 13B are arranged between the restraining walls 27A and 27B, the amount of generated heat increases when the resistance heating elements 13A and 13B are energized. For this reason, the molten resin of the upper case member 11A and the lower case member 12 may be vaporized between the restraining walls 27A and 27B.

  When there is no exhaust hole 61, the vaporized resin stays around the connecting portion 43, so that a cavity may be formed. When a cavity is formed around the connecting portion 43, the sealed chambers 2A and 2B are communicated with each other by the cavity, and the sealing performance of the sealed chambers 2A and 2B may be impaired.

  On the other hand, in the second embodiment, the vaporized resin is discharged from the exhaust hole 61. As a result, the formation of a cavity around the connecting portion 43 is suppressed. As a result, it can suppress more that the airtightness of the airtight chambers 2A and 2B of the airtight container 1 is impaired.

  In the region where the two power receiving units 42A of the resistance heating elements 13A and 13B are arranged side by side and the region where the two power receiving units 42B are arranged side by side, the resistance heating elements 13A and 13B are energized. Since the calorific value becomes large, the resin may vaporize. However, since the resin vaporized around the power receiving units 42A and 42B is discharged from the power supply ports 26, 37A and 37B, the generation of cavities at these positions is suppressed.

(Third embodiment)
In 3rd Embodiment, 12 A of lower case members are used instead of the lower case member 12 of 1st Embodiment mentioned above. 16 is a partially enlarged cross-sectional view of the same cut surface as in FIG. 14 with the lower case member 12 of FIG. 7 replaced with the lower case member 12A.

  As shown in FIG. 16, in the lower case member 12 </ b> A, in the region where the connecting portions 43 of the resistance heating elements 13 </ b> A and 13 </ b> B are disposed, the joining surface 33 The taper surface becomes lower so that the distance from the connecting portion 43 becomes wider toward the end from the center.

  As a result, on the lower side of the connecting portion 43, the melting of the joint surface 33 proceeds from the center of the connecting portion 43 in the left-right direction toward both ends. In addition, since the lower joint surface 33 of the connection portion 43 is a tapered surface, the connection surface 43 on the upper side of the connection portion 43 is gradually moved outward from the center of the connection portion 43 in the left-right direction. A pressing force is applied. Thereby, in the upper side of the connection part 43, the fusion | melting of the joint surface 23 advances toward the both ends from the center of the connection part 43 in the left-right direction.

  As described above, in the third embodiment, in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed, the joint surfaces 23 and 33 are melted from the center of the connecting portion 43 in the left-right direction toward both ends. To go. As a result, the molten resin fills the gap around the connecting portion 43 and the melting of the resin on the joint surfaces 23 and 33 proceeds from the center of the connecting portion 43 to both ends in the left-right direction.

  Here, unlike the third embodiment, when the joint surface 33 is not a tapered surface but a flat surface on the lower side of the connecting portion 43, the molten resin does not fill the gap around the connecting portion 43, and the constraining walls 27A, 27A, There is a risk of flowing into the gap between 27B and the grooves 38A, 38B. As a result, a cavity is formed around the connecting portion 43, and the sealing performance of the sealed chambers 2A and 2B may be impaired.

  On the other hand, in the third embodiment, as described above, the molten resin fills the gap around the connecting portion 43 and the melting of the resin at the joint surfaces 23 and 33 proceeds. The formation of cavities around the periphery is suppressed. Accordingly, it is further suppressed that the sealed chambers 2A and 2B are communicated with each other and the sealing performance of the sealed chambers 2A and 2B is impaired.

(Other embodiments)
As described above, the present invention has been described according to the first to third embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the first to third embodiments described above, the case where the sealed container 1 having the two sealed chambers 2A and 2B is formed has been described. However, the sealed container may have three or more sealed chambers. In this case, the resistance heating element 13 includes three or more annular forming portions 41 connected via the connecting portion 43. The upper case members 11 and 11A have three or more container parts 21, and the lower case members 12 and 12A have three or more lid parts 31. In the first embodiment, the number of sealed chambers included in the sealed container is not limited to a plurality, and the number of sealed chambers may be one.

  In the second embodiment described above, the lower case member 12 may also be provided with an exhaust hole that communicates the joint surface 33 with the outside in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed. . Further, only the lower case member 12 of the upper case member 11 and the lower case member 12 is provided with an exhaust hole that communicates the joint surface with the outside in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed. May be.

  In the third embodiment described above, the joint surface 23 of the upper case member 11 in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed is also the center of the connecting portion 43 in the extending direction (left-right direction) of the connecting portion 43. It is good also as a taper surface which becomes high so that a space | interval with the connection part 43 may become wide as it goes to an end from the side. Further, only the upper case member 11 of the upper case member 11 and the lower case member 12 may have a joint surface in a region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed as a tapered surface.

  In the third embodiment described above, the exhaust holes that connect the joint surface 23 of the upper case member 11 and the outside in the region where the connecting portions 43 of the resistance heating elements 13A and 13B are disposed, and the joint surface 33 of the lower case member 12A. At least one of exhaust holes that communicate with the outside may be provided.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 Sealed container 2A, 2B Sealed chamber 11, 11A Upper case member 12, 12A Lower case member 21A, 21B Container part 22 Flange 23, 33 Joint surface 13A, 13B Resistance heating element 31A, 31B Cover part 32 Peripheral wall part 41A, 41B Annular Forming part 42A, 42B Power receiving part 43 Connecting part 46A, 46B Annular part 61 Exhaust hole

Claims (3)

The first and second resistance heating elements each having a semi-annular annular forming portion and a plurality of bundling portions connected to the annular forming portion are mutually connected to form the annular portion by the annular forming portion. Along the bundling portions, and arranged between the respective joint surfaces of the first and second molded products made of thermoplastic resin,
In the state where the annular forming portion is unconstrained in the direction parallel to the joining surface, the first and second resistance heating elements are energized, and the first molded product is generated by the heat generation of the first and second resistance heating elements. And the second molded product are welded to form a sealed container. Each of the first and second resistance heating elements includes a plurality of the annular forming portions connected via the bundle portions, and forms the plurality of annular portions by aligning the bundle portions with each other. Is,
The first and second molded products form a plurality of sealed spaces by being welded to each other,
In the region where the bundled portion between the annular portions is disposed, at least one of the first and second molded products is formed with an exhaust hole that communicates the joining surface and the outside, and the annular portion 2. The heat welding method according to claim 1, wherein the resin of the first and second molded products vaporized by the heat generation of the bundled portion is discharged from the exhaust hole.   In the region where the bundled part between the annular parts is arranged, at least one of the first and second molded products has the joining surface of the bundled part in the extending direction of the bundled part between the annular parts. As the distance from the center to the end becomes a tapered surface, the gap between the bundle portions becomes wider, and the melting of the joint surface sandwiching the bundle portions between the annular portions is from the center in the extending direction of the bundle portions to both ends. The heat welding method according to claim 2, wherein the heat welding method proceeds toward the heat welding.