WO2013129474A1

WO2013129474A1 - Welding device

Info

Publication number: WO2013129474A1
Application number: PCT/JP2013/055123
Authority: WO
Inventors: 歩織田; 義治松井; 正孝三徳
Original assignee: 株式会社フロウエル
Priority date: 2012-02-29
Filing date: 2013-02-27
Publication date: 2013-09-06
Also published as: JPWO2013129474A1; JP6101946B2; TW201406530A; TWI613063B; KR20140141610A

Abstract

A welding device that: makes it possible for not only the heater but also the welding head as well as the device as a whole to be made more lightweight and smaller; is able to increase welding efficiency with a simple configuration; and is also able to reduce cost significantly. The welding head (11) that encircles and holds the junction (3) of a coupling (1) and a tube (2) has multiple clampers (20) that can be opened and closed. The heaters (30), which are provided along the inner circumference of each clamper (20), are obtained by overlaying sheet-shaped insulating materials (32) on the front and back of a sheet-shaped heat-generating body (31), fixing same to a thin metal plate (33) and bending to an arc shape that follows the inner circumferential surface of the clamper (20). When the respective clampers (20) are in the closed position, the heaters (30) are disposed so as to surround the outer circumference of the junction (3) continuously in the circumferential direction without a gap, the two respective adjacent end sections (30a) abutting against each other.

Description

Welding equipment

The present invention relates to a welding apparatus that heats and welds the pipe end portion of a heat-weldable joint and the end portion of a heat-weldable tube from the outer peripheral side of the joint portion.

Conventionally, for example, two welding apparatuses already proposed by the applicant of the present application are known as welding apparatuses for heat-welding resin tubes and the like (see Patent Documents 1 and 2). Each apparatus is provided with a welding head for sandwiching and heating a joint portion between resin tubes to be welded from both sides. This welding head has a pair of clampers for fixing the joint portion between the resin tubes, a pair of heat conducting members and a pair of heaters housed in the housing recesses of the pair of clampers.

The pair of clampers can swing between an open position that is open and a closed position that is closed. When the clampers are in the open position, the joint portion between the resin tubes is placed at a predetermined position on one clamper, It can be fixed by swinging the clamper to the closed position and sandwiching the resin tube. Thereafter, the joint can be melted and welded by heating the joint with a heater.

Here, the heater is formed by a plate-like resistance heating material so as to be along the heat conducting member, and is arranged so as to heat the joint through the heat conducting member. More specifically, for example, a nichrome plate having a thickness of 0.2 mm is used as the plate-like resistance heating material, and the resistance value is as small as 0.1Ω or less. Further, as the heat conducting member, for example, a member formed in a semi-cylindrical shape with a heat conductive ceramic material has been used.

Japanese Patent No. 4109540 JP 2008-69880 A

However, in each of the conventional technologies as described above, a resistance heating material such as a nichrome plate is used as a specific configuration of the heater, and the resistance value is very small even if the heater itself can be downsized. Electric current was needed. For this reason, since a welding head capable of supplying a large current, a jig power supply, and a power cable are necessary, there is a problem that the entire apparatus is reduced in weight and compact design, and it becomes an obstacle when reducing costs. Further improvements were desired.

The present invention has been made by paying attention to the problems of the prior art as described above, and is based on the premise that a heater generally uses a planar heating element having a large resistance value. As a result, it is possible to reduce the weight and size of the welding head as well as the entire device, as well as the heater, increase the welding efficiency with a simple configuration, and reduce the cost significantly. It is intended to provide.

The gist of the present invention for achieving the object described above resides in the inventions of the following items.
[1] Heat welding from the outer peripheral side of the joint (3) in a state where the pipe end of the heat weldable joint (1) and the end of the heat weldable tube (2) are joined to each other. In the welding apparatus (10) to be made,
A welding head (11) for holding the joint (3) in a circulating state, and heating the joint (3) from the outer peripheral side,
The welding head (11) includes a plurality of clampers (20) divided in a circumferential direction that circulates around the joint (3), and a plurality of heaters provided along the inner peripheral side of each clamper (20). 30)
Each clamper (20) is displaceably connected to a closed position that is closed so as to go around the joint (3) and an open position that is opened so as to be separated from the joint (3),
Each heater (30) covers the front and back of the sheet heating element (31) with a sheet-like insulating material (32), which is fixed to a thin metal plate (33), and the inner periphery of the clamper (20). Curved in an arc along the surface,
When each clamper (20) is in the closed position, each heater (30) abuts each other at both ends (30a) adjacent to each other, and the outer periphery of the joint (3) is spaced in the circumferential direction. A welding apparatus (10) characterized in that the welding apparatus is arranged so as to continuously surround it.

[2] The heaters (30) are respectively supported by a frame member (35) having a curved shape along the outer periphery thereof, and the clampers (20) are supported by the frame members (35). The welding apparatus (10) according to [1], which is attached.

[3] The welding apparatus (10) according to [1] or [2], wherein a portion of the clamper (20) that directly engages the tube (2) is formed of an elastic material. ).

[4] Among the clampers (20), one clamper (20) is provided with an air supply inlet (24), and the other clamper (20) is provided with an air supply outlet (25).
After the welding of the joint (3) is completed, air is forcibly introduced into the inside through the air feed inlet (24) and exhausted to the outside through the air feed outlet (25). The welding apparatus (10) according to [1], [2] or [3], wherein (3) and each heater (30) are cooled.

Next, the operation based on the above solution will be described.
When welding the joint portion (3) between the pipe end portion of the joint (1) and the end portion of the tube (2) by the welding device (10) described in [1], first, the welding device (10) is in the open position. A joint (3) is arranged between each clamper (20). Next, each clamper (20) is displaced from the open position to the closed position to hold the joint (3) in a circulating state, and then each heater (30) on the inner peripheral side of each clamper (20). Each generates heat.

The joint (3) is heated and welded by the heat generated by each heater (30). Thereafter, each clamper (20) is displaced from the closed position to the open position, and the joint (3) is taken out between each clamper (20). In this way, by displacing each clamper (20) between the closed position and the open position, the joint (3) can be easily held or detached. Here, each clamper (20) and each heater (30) do not need to be a pair divided into two in the circumferential direction, and may be configured to be divided into three or four, for example.

Each heater (30) covers the front and back of the sheet heating element (31) with a sheet-like insulating material (32), which is fixed to a metal thin plate (33), and the inner peripheral surface of the clamper (20). It is curved in a circular arc shape along. Here, the sheet heating element (31) is not only thinner than a resistance heating material such as a conventional nichrome plate, but also has a large resistance value as one of its characteristics. Can generate heat. Therefore, the welding head (11), the jig power supply, the power cable, and the like can be simplified.

Moreover, since the sheet heating element (31) is covered with the sheet-like insulating material (32), the insulator is interposed between the heaters (30) even when the heaters (30) are close to each other. There is no need to let them. Moreover, by being fixed by the metal thin plate (33), it can be kept in a curved shape in an arc along the inner peripheral surface of the clamper (20) due to its plasticity. In addition, the metal thin plate (33) can not only replace the member for heat conduction, but also can increase the durability and rigidity of the heater (30) itself, and can further coat the releasable material (34). It can also be used as a surface to be processed.

When each clamper (20) is in the closed position, each heater (30) abuts each other at both ends (30a) adjacent to each other, and the outer periphery of the joint (3) is continuous without any gap in the entire circumferential direction. And are arranged so as to surround them. As described above, such an arrangement can be achieved by ensuring the insulation of the heater (30) itself from the insulating material (32) and further providing durability and the like by the metal thin plate (33). With such an arrangement, the heat generation efficiency can be further increased, and the joint portion (3) can be welded uniformly and uniformly over the entire circumferential direction.

According to the welding apparatus (10) described in the above [2], each heater (30) is supported by a frame member (35) having a curved shape along the outer peripheral side thereof, and the frame member ( 35) to each clamper (20) of the welding head (11). By supporting the heater (30) on the frame member (35) in this way, the curved shape of the heater (30) itself can be maintained more firmly. Here, the frame member (35) is suitable for processing with a metal material in terms of ease of processing and cost. The support of the heater (30) with respect to the frame member (35) preferably has a point contact structure so that the contact area is as small as possible from the viewpoint of avoiding heat loss.

According to the welding device (10) described in [3], a portion of each clamper (20) that directly engages with the tube (2) is formed of an elastic material. As a result, the cushioning property is ensured in the portion that directly engages the flexible tube (2), the deformation of the tube (2) can be suppressed, the coefficient of friction increases, and the displacement can be prevented. it can.

According to the welding apparatus (10) described in [4], among the clampers (20), one of the clampers (20) is provided with the air supply inlet (24) and the other clamper (20) is supplied with air. An outlet (25) is provided. And after welding of the said junction part (3) is complete | finished, while air is forcedly introduced into the inside from the said air supply inlet (24), it is exhausted outside from the said air supply outlet (25), A series The heater (30) can be quickly cooled by the air flow, and the joint (3) is also cooled.

According to the welding apparatus according to the present invention, it is assumed that a sheet heating element having a large resistance value is generally used for the heater, and by making improvements based on this, not only the heater but also the entire apparatus. The weight can be reduced and the size can be reduced, the welding efficiency can be increased with a simple configuration, and the cost can be greatly reduced.

It is a perspective view which shows the state in which the clamper of the welding apparatus which concerns on embodiment of this invention exists in an open position, and the junction part of the joint and the tube was mounted. It is a perspective view which shows the state where the clamper of the welding apparatus which concerns on embodiment of this invention exists in a closed position, and the junction part of the joint and the tube was hold | maintained. It is a perspective view which shows the state which the clamper of the welding apparatus which concerns on embodiment of this invention exists in an open position. It is a front view which shows the state which the clamper of the welding apparatus which concerns on embodiment of this invention exists in an open position. It is a perspective view which partially cuts and shows the state which the clamper of the welding apparatus which concerns on embodiment of this invention exists in an open position. It is a front view which partially cuts and shows the state which the clamper of the welding apparatus which concerns on embodiment of this invention exists in an open position. It is a perspective view which shows the state which supported the heater of the welding apparatus which concerns on embodiment of this invention to the frame member. It is a front view which shows the state which supported the heater of the welding apparatus which concerns on embodiment of this invention to the frame member. It is a perspective view which cuts and shows the heater of the welding apparatus which concerns on embodiment of this invention partially. It is (a) front view and (b) side view which show the state which curved the heater of the welding apparatus which concerns on embodiment of this invention. It is a front view which expands and shows the joint part and the junction part of a tube which are welded with the welding apparatus which concerns on embodiment of this invention.

Hereinafter, various embodiments representing the present invention will be described with reference to the drawings.
1 to 10 show an embodiment of the present invention.
The welding apparatus 10 according to the present embodiment is heated from the outer peripheral side of the joint portion 3 in a state where the pipe end portion of the heat weldable joint 1 and the end portion of the heat weldable tube 2 are joined to each other. This is a device for welding. Hereinafter, a case where a fluororesin material is used as a heat-weldable material will be described as an example.

The joint 1 and the tube 2 constitute a flow conduit for a cleaning liquid such as pure water used in a clean room at a semiconductor chip manufacturing site or the like, and other general chemical liquids, for example. The joint 1 is a cylindrical member, and two

positioning protrusions

1a and 1b are formed in parallel on the outer periphery thereof. Each

positioning protrusion

1a, 1b is positioned by fitting with a clamper 20 described later at the time of welding. The tube 2 is a hollow cylindrical tube.

As shown in FIG. 11 in an enlarged manner, the joint portion 3 has an end portion of the tube 2 fitted to a tube end portion of the joint 1, and a housing 4 that is a heat-resistant cylinder is further fitted. The housing 4 is a resin molded product having a melting point higher than that of the joint 1 and the tube 2, and prevents the shape from collapsing during welding. The

positioning protrusions

1 a and 1 b of the joint 1 are formed so as to be arranged in the vicinity of the joint 3. The joint 1 and the tube 2 are made of a fluororesin material such as PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer). The housing 4 is made of a fluororesin material such as polytetrafluoroethylene.

As shown in FIGS. 1 and 2, the welding apparatus 10 can be held in a state where it circulates the joint 3, and includes a welding head 11 for heating the joint 3 from the outer peripheral side. The welding head 11 includes a plurality of clampers 20 that are divided in the circumferential direction that circulates around the joint portion 3, and a plurality of heaters 30 that are provided along the inner peripheral side of each clamper 20. A plurality of clampers 20 and heaters 30 are provided in pairs in this embodiment.

As shown in FIGS. 3 to 6, each clamper 20 is movably connected to a closed position that is closed so as to go around the joint 3 and an open position that is opened so as to be separated from the joint 3. ing. More specifically, one end of the pair of clampers 20 is slidably connected to a closed position where the joint 3 is sandwiched from both sides and an open position where the gap is widened. Thus, although not shown in the drawings, each clamper 20 is connected to each other by a hinge or the like so as to be swingable, and the other end is provided with a general-purpose stopper or the like that can be restrained to a closed position. Yes.

Each clamper 20 is formed of a metal material (for example, stainless steel) in a semicircular case shape. More specifically, the clamper 20 includes a semicircular arc-shaped front and rear side walls 21 and an outer peripheral wall 22, and an inner peripheral side thereof is open, and the inside serves as an accommodating recess 23 for accommodating the heater 30. Yes. As shown in FIG. 2, the clampers 20 are configured to communicate with each other when they are in the closed position and are sealed from the outside of the clampers 20. One clamper 20 is provided with an air supply inlet 24, and the other clamper 20 is provided with an air supply outlet 25. After the welding of the joint portion 3 is completed, air is forcibly introduced into each clamper 20 from the air supply inlet 24 and exhausted to the outside from the air supply outlet 25.

In the side walls 21 at the front and rear of each clamper 20, the semicircular arc-shaped opening edge on the inner peripheral side is a portion that is directly engaged with and held by the tube 2 or the joint portion 3. Of these, one opening edge is a portion that directly engages the tube 2 when each clamper 20 is in the closed position, and the portion is formed of an elastic material. Specifically, a mounting rail 26 having a groove-shaped cross section is provided so as to extend in a semicircular arc shape along the opening edge on the inner peripheral side, and a tube material 27 made of an elastic material is provided in the groove of the mounting rail 26. A part of the outer periphery protrudes outward and is fitted into the tube 2. Specifically, for example, a tube material made of silicon may be adopted as the tube material 27.

The other opening edge is a portion that directly engages with the joint portion 3 when each clamper 20 is in the closed position, and a joint holding portion 28 is provided in the portion. The joint holding part 28 is formed as a flange protruding along the other opening edge so as to fit into a recess between the positioning

protrusions

1a, 1b of the joint 1. The joint 1 held by the joint holding portion 28 does not shift even if a force is applied in a direction in which the joint 1 is removed from the clamper 20, and the state of being securely held is maintained. The

positioning protrusions

1 a and 1 b are provided at positions adjacent to the joint portion 3.

As shown in FIGS. 9 and 10, the heater 30 covers the front and back surfaces of the sheet heating element 31 with a sheet-like insulating material 32, which is fixed to a thin metal plate 33, along the inner peripheral surface of the clamper 20. It is curved in a circular arc shape. Here, the planar heating element 31 is a thin film-like heating element that generates heat by flowing electricity, and its configuration is general, and thus detailed description thereof is omitted.

The planar heating element 31 according to the present embodiment is formed in a narrow tape shape, and is designed so as to obtain a uniform heat distribution by applying a circuit to almost the entire area. Such a planar heating element 31 is not only very thin and soft, but also has a large resistance value as an electrical characteristic. For example, in the case of a conventional nichrome plate used for an equivalent device, the resistance value is 0.1Ω or less and the current is about several tens of A. The resistance value is about several Ω, and the current is about several A. By manufacturing the heater 30 with such a planar heating element 31, it is possible to reduce the current, and consequently to save power, and to reduce the size of the clamper 20 to be housed.

The sheet-like insulating material 32 that covers the front and back surfaces of the sheet heating element 31 may be anything as long as it is a sheet-like material having insulating properties. Specifically, for example, what is called a flexible mica sheet is used. Is suitable. This is a moldable composite material in which mica (mica) is infiltrated into an organic silicon resin having high temperature resistance. The entire area other than the electrode portions at both ends of the planar heating element 31 is covered from the front and back by the insulating material 32. Further, this is fixed to the thin metal plate 33 and is bent in an arc shape along the inner peripheral surface of the clamper 20. In the present embodiment, the sheet heating element 31 covered with the insulating material 32 is sandwiched from the front and back by the metal thin plate 33, but is not limited to this configuration, and only along one side. The metal thin plate 33 may be fixed.

As the metal thin plate 33, for example, a material having equivalent workability and heat resistance such as nichrome and stainless steel may be used. The entire heater 30 can be bent into a desired shape by the plasticity of the metal thin plate 33. Specifically, as shown in FIG. 10, the heater 30 is bent into a semicircular arc shape. Further, both end portions 30a of the heater 30 are bent on the same plane, and are formed in a flange shape so that the pair of heaters 30 are in contact with each other. Although not shown, heater wires are connected to both end portions 30a. Each heater 30 is wired to the power supply unit via a heater wire, and heating control is possible.

Further, as shown in FIGS. 7 and 8, the heater 30 is supported by a frame member 35 having a curved shape along the outer peripheral side thereof, and the housing recess 23 of the clamper 20 is interposed through the frame member 35. Is attached. Here, when each clamper 20 is in the closed position, the pair of heaters 30 are arranged so that both end portions 30a abut each other vertically and continuously surround the outer periphery of the joint portion 3 in the circumferential direction without any gap. ing. Such an arrangement is possible because the planar heating element 31 of the heater 30 is insulated by the insulating material 32.

More specifically, the frame member 35 has a structure for preventing the shape of the heater 30 from being deformed, in addition to maintaining the shape of the heater 30 by the metal thin plate 33. The frame member 35 is a groove-shaped cross-section member obtained by processing a metal material so as to match the semicircular arc shape of the heater 30, and the inner peripheral side is open, and the heater 30 is floated along the inside of the opening. Support in shape. That is, the heater 30 is supported by the mounting piece 33a that locally protrudes so as not to contact the frame member 35 as much as possible. Thereby, a gap for cooling the heater is formed between both side edges of the heater 30 and the opening side edge of the frame member 35.

Further, both end portions 35 a of the frame member 35 are formed in a flange shape like the both end portions 30 a of the heater 30. The both end portions 35a are provided with attachment pieces 35b that are screwed to the fixing seat 29 on the inner wall of the accommodating recess 23 of the clamper 20. The frame member 35 is not limited to a metal material, and may be formed of a resin material having a strength capable of maintaining rigidity and a high temperature resistance. The attachment piece 33a may be provided not on the metal thin plate 33 side of the heater 30 but on the frame member 35 side.

The welding head 11 configured as described above constitutes a welding apparatus 10 in combination with a power supply unit (not shown) to which a heater wire extending from each heater 30 is connected. Here, in addition to the heater 30, a temperature sensor is incorporated in each clamper 20 of the welding head 11 although not shown.

Here, with regard to the temperature sensor, in the conventional apparatus, the sheath type thermocouple is configured to contact the nichrome plate, but in this embodiment, the thermocouple is directly applied to the metal thin plate 33 or the frame member 35 of the heater 30. Just weld. Such a temperature sensor can be attached because the thin metal plate 33 is insulated from the planar heating element 31 by the insulating material 32. According to the configuration of such a temperature sensor, cost reduction and accurate temperature measurement are possible. The clamper 20 is made of a metal material (for example, stainless steel) instead of a conventional bake material, so that deterioration over time (distortion due to heating) can be suppressed.

Further, as described above, since the heater 30 is manufactured by the planar heating element 31, not only the welding head 11 is reduced in size by the structure of the heater 30 itself but also the resistance of the heater 30 is small. Welding with electric current is possible. As a result, it is possible to eliminate the large-diameter cable and connect with a thin heater wire, and it is also possible to reduce the size of the power source and the power source unit that houses the power source. In particular, the welding head 11 (clamper 20) has a structure that mainly accommodates the heater 30, and the thickness in the radial direction can be suppressed as much as possible in the illustrated ring shape.

Next, the operation of the welding apparatus 10 according to the present embodiment will be described.
As shown in FIG. 1, when welding the joint 3 between the pipe end of the joint 1 and the end of the tube 2 by the welding device 10, each clamper 20 is opened to the open position, and each The joint 3 is disposed between the clampers 20. At this time, the joint holding part 28 of one clamper 20 (the lower side in FIG. 1) may be disposed so as to fit into the recesses between the positioning

protrusions

1 a and 1 b of the joint 1.

When the other clamper 20 (upper side in the figure) is swung to the closed position, the joint holding portion 28 of the clamper 20 is also fitted in the recess between the positioning

protrusions

1a and 1b in the upper half of the joint 1. As a result, the joint portion 3 is sandwiched from above and below by the pair of clampers 20, and the joint portion 3 can be held in a circulating state. At this time, since the tube material 27 at the opening edge on the inner peripheral side of each clamper 20 is elastically brought into contact with the tube 2 in the vicinity of the joint portion 3, the deformation of the tube 2 can be suppressed. it can.

In this way, when each clamper 20 is in the closed position, the pair of heaters 30 are arranged so that both end portions 30a abut each other vertically and continuously surround the outer periphery of the joint portion 3 without any gap in the entire circumferential direction. Is done. Such an arrangement is made possible by the planar heating element 31 of the heater 30 being insulated by the insulating material 32 and having durability and the like by the metal thin plate 33. As a result, the heat generation efficiency can be increased, and the joining portion 3 can be welded uniformly and uniformly over the entire circumferential direction.

Each heater 30 is energized and generates heat by operating a start switch (not shown) in the power supply unit. Here, when the same amount of electric power is supplied to each heater 30, each heater 30 has the same shape and the same resistance, so the amount of heat generated from each heater 30 is also the same. As described above, since both end portions 30a of each heater 30 are in contact with each other, an insulator is interposed between both ends of each heater as in the conventional apparatus, and the temperature of this portion may be locally reduced. Absent. Therefore, the junction part 3 can be heated uniformly from the whole circumference direction, and the favorable welding result of the junction part 3 can be obtained.

As shown in FIG. 9, each heater 30 covers the front and back of the planar heating element 31 with a sheet-like insulating material 32, which is fixed from the front and back with a metal thin plate 33, along the inner peripheral surface of the clamper 20. Curved in an arc. The sheet heating element 31 is not only thinner than a resistance heating material such as a conventional nichrome plate, but also has a large resistance value as one of its characteristics, so that it can sufficiently generate heat even at a relatively low current. it can. Therefore, the welding head 11, the power supply unit, the power supply cable, and the like can be simplified.

Moreover, since the front and back surfaces of the planar heating element 31 are covered with the sheet-like insulating material 32, it is not necessary to interpose an insulator as described above even when the heaters 30 are close to each other. Further, by being fixed to the metal thin plate 33, it is possible to keep the shape curved in an arc along the inner peripheral surface of the clamper 20 due to the plasticity of the metal. In addition, the thin metal plate 33 can be used as a substitute for the heat conducting member, and the durability and rigidity of the heater 30 itself can be increased.

Further, a releasable material 34 is laminated on the surface of the metal thin plate 33 which is the inner peripheral side of each heater 30. Accordingly, it is not necessary to separately prepare a heat conducting member obtained by processing ceramic as in the prior art for mold release. In addition, for the insulating material 32 that covers the front and back surfaces of the planar heating element 31, it is difficult to laminate a releasable material by means of ceramic spraying or the like. It is possible to coat a releasable material without difficulty.

Furthermore, in the case of a conventional heat conduction member that is a separate body, it is necessary to be molded with a strong strength because it is a processed ceramic product. On the other hand, if the releasable material 34 is laminated as in the present embodiment, heat conduction is not impaired, and heat generation from the planar heating element 31 is efficiently transmitted while ensuring releasability. be able to. Of course, the lamination of the releasable material 34 is not limited to ceramic spraying.

As shown in FIG. 7, each heater 30 is supported by a frame member 35 having a curved shape along the outer peripheral side thereof, and is attached to each clamper 20 via the frame member 35. By supporting the heater 30 on the frame member 35 in this way, the curved shape of the heater 30 itself can be maintained more firmly.

The heater 30 is supported by the attachment piece 33a so as to float inside the opening of the frame member 35, and the frame member 35 is also attached to the clamper 20 by the both end portions 35a so that the contact area becomes as small as possible. ing. As a result, a gap for cooling the heater is generated between both side edges of the heater 30 and the opening side edge of the frame member 35, and a large gap is also generated between the frame member 35 and the clamper 20. For this reason, when the heater 30 generates heat, the gaps serve as a heat insulating layer, making it difficult for the heat of the heater 30 to be transmitted to the clamper 20 and preventing heat loss.

Further, each heater 30 is connected to a power supply unit via a heater wire, and heating control is possible. Thereby, according to the concrete material, shape, etc. of the junction part 3 which is the welding object, an optimal heat generation state can be easily realized by switching each heater 30 on / off or adjusting the current. Further, in order to adjust the variation in the heat generation temperature of each heater 30, in addition to adjusting the fixing position of the heater 30 or the frame member 35, a resistance element is inserted in series for each heater 30 so that each heat generation temperature is reduced. It is also possible to adjust.

Each clamper 20 communicates with each other when in the closed position and is sealed to the outside of each clamper 20. One clamper 20 is provided with an air supply inlet 24, and the other clampers 20 is provided with an air supply outlet 25. After the welding of the joint portion 3 is completed, air is forcibly introduced into each clamper 20 from the air supply inlet 24 and exhausted to the outside from the air supply outlet 25, whereby a series of air flows. Thus, the heater 30 can be quickly cooled, and the joint 3 is also cooled.

And after cooling each heater 30, if a pair of clamper 20 is rock | fluctuated from a closed position to an open position and the space | interval between each heater 30 is expanded, the junction part 3 can be taken out from there. Thus, by swinging the clampers 20 with each other, the joint portion 3 of the joint 1 and the tube 2 can be easily fixed so as not to slip and the joint 1 and the like can be easily taken out. be able to.

The embodiments of the present invention have been described above with reference to the drawings. However, the specific configuration is not limited to the above-described embodiments, and the present invention can be changed or added without departing from the scope of the present invention. Included in the invention. For example, the case where the joint 1 and the tube 2 are made of synthetic resin as a heat-weldable material has been described. However, the joint 1 and the tube 2 can also be applied to a metal joint or tube.

Further, the tube 2 welded to the joint 1 may be a joint instead of the tube. In this case, heat-weldable resin joints are welded together. Further, in the present embodiment, the plurality of clampers 20 and the heaters 30 are provided in pairs of two divided in the circumferential direction. However, it is not always necessary to align the pairs, for example, three or four in the circumferential direction. You may comprise so that it may do.

The welding apparatus according to the present invention can be widely applied as an apparatus for welding joints and tubes constituting flow channels for cleaning liquids such as pure water and other general chemicals used in a clean room at a semiconductor chip manufacturing site or the like. it can.

DESCRIPTION OF SYMBOLS 1 ... Joint 2 ... Tube 3 ... Joining part 4 ... Housing 10 ... Welding apparatus 11 ... Welding head 20 ... Clamper 21 ... Side wall 22 ... Outer peripheral wall 23 ... Housing recessed part 24 ... Air supply inlet 25 ... Air supply outlet 26 ... Mounting rail 27 ... Tube material 28 ... Joint holding part 29 ... Fixed seat 30 ... Heater 31 ... Planar heating element 32 ... Insulating material 33 ... Metal thin plate 33a ... Mounting piece 34 ... Release material 35 ... Frame member 35a ... Both ends 35b ... Mounting piece

Claims

A welding apparatus that heats and welds the pipe end of the heat weldable joint (1) and the end of the heat weldable tube (2) from the outer peripheral side of the joint (3). In (10),
A welding head (11) for holding the joint (3) in a circulating state, and heating the joint (3) from the outer peripheral side,
The welding head (11) includes a plurality of clampers (20) divided in a circumferential direction that circulates around the joint (3), and a plurality of heaters provided along the inner peripheral side of each clamper (20). 30)
Each clamper (20) is displaceably connected to a closed position that is closed so as to go around the joint (3) and an open position that is opened so as to be separated from the joint (3),
Each heater (30) covers the front and back of the sheet heating element (31) with a sheet-like insulating material (32), which is fixed to a thin metal plate (33), and the inner periphery of the clamper (20). Curved in an arc along the surface,
When each clamper (20) is in the closed position, each heater (30) abuts each other at both ends (30a) adjacent to each other, and the outer periphery of the joint (3) is spaced in the circumferential direction. A welding apparatus (10) characterized in that the welding apparatus is arranged so as to continuously surround it.
The heaters (30) are respectively supported by arc-shaped frame members (35) along the outer periphery thereof and attached to the clampers (20) via the frame members (35). The welding apparatus (10) according to claim 1, characterized in that:
The welding device (10) according to claim 1 or 2, wherein a portion of the clamper (20) that directly engages with the tube (2) is formed of an elastic material.
Among the clampers (20), one clamper (20) is provided with an air supply inlet (24), and the other clamper (20) is provided with an air supply outlet (25).
After the welding of the joint (3) is completed, air is forcibly introduced into the inside through the air feed inlet (24) and exhausted to the outside through the air feed outlet (25). The welding apparatus (10) according to claim 1, 2 or 3, wherein (3) and each heater (30) are cooled.