JP2012135956A - Melting heater for resin made annular work and welder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melting heater for resin made annular work which can firmly weld even a resin made annular work of high melting point with small diameter by heating to a predetermined high temperature state, can join the resin made annular works by evenly melting by heating with a temperature distribution appropriate for the shape of the end face of the annular work, and can miniaturize a welder, while securing whole compactness and to provide the welder.SOLUTION: There is provided the melting heater for resin made annular work which is provided with electrodes 2 at both ends in right and left direction of both faces of the heater plate 1 made of the rectangular shape conductive ceramic. In this melt heater, length L1 of the electrode 2 given to the vertical direction of the heater plate 1 is formed shorter than the length L2 of the vertical direction of the heater plate, and the heating area T of the heater plate 1 is made a conical shape temperature distribution.

Description

  The present invention relates to a melting heater for resinous annular workpieces used when welding pipe ends of resinous annular workpieces with a welding machine, and particularly suitable for joining small-diameter annular workpieces used in the field of semiconductor manufacturing. The present invention relates to a non-contact type melting heater and a welding machine.

  Conventionally, chemical resistance, heat resistance, high cleanliness, and the like are required for pipes used in production lines in the field of semiconductor manufacturing. For example, a fluororesin such as PFA (perfluoroalkoxyethylene copolymer resin) is said to be most suitable as a pipe that satisfies these requirements. A pipe used in a pipe line of a semiconductor production line may be provided by welding weld joints made of fluororesins or workpieces made of an annular thermoplastic resin of a joint and a tube. In this case, the annular workpiece is often joined by end face butt welding, and a welding machine is used in that case. When welding workpieces with a welding machine, this welding machine is provided with a non-contact type heater. When the end surfaces of both workpieces are heated and melted with this heater and the workpiece end surfaces are in an appropriate molten state, the workpieces are joined together. Press to weld.

As a heater for this type of welding machine, for example, a heater having a structure in which a heating wire is disposed between two heat generating plates made of ceramic plates is often used. In the heater, when a voltage is applied to the heating wire, the heat generated by the heating wire is transferred to the ceramic plate, and the heating plate generates heat to melt the workpiece.
On the other hand, the thin plate-shaped far infrared heater disclosed in Patent Document 1 has a structure in which a ceramic layer having a double structure is used as a heat generating plate, and an electrode formed of an aluminum sprayed film is provided on the end side and the side of the ceramic layer. It has become. This heater is placed close to the pipe end face of the pipe clamped on the same axis by a work clamp, and the ceramic layer generates heat when a voltage is applied through the lead wire of the terminal connected to the electrode, The work is melted by this heat generation. The heater of the same document can suppress the heat generation by adjusting the heat generation temperature of the electrode by changing the spraying length of the side surface section electrode, and this heater is an electrode on the end side and the side surface. The arrangement is intended to control the temperature distribution by suppressing the heat generation of the terminal portion.
Moreover, as this kind of heater, thin film electrodes made of aluminum are provided on both sides of the ceramic plate, and further, the electrode arrangement side of the heat generating plate is extended so that the horizontal dimension of the heat generating plate is longer than the vertical dimension. Heated heaters are known.

  In particular, it is desirable that the shape of the pipe used in the semiconductor field after joining should be an appropriate melting amount at the joint and the entire circumference should be uniform. It is necessary to melt both ends of the workpiece to be welded evenly. For this reason, the heater is required to have a uniform heat distribution suitable for the work to be melted, with the heat generation temperatures of the front and back surfaces being constant. In this case, since the melting point of a fluororesin such as PFA is higher than that of a general resin such as polyethylene, it is important to set the heating temperature of the heater high.

JP 2001-313156 A

  However, in a heater having a structure in which a heating wire is arranged between two ceramic plates, the heating wire is oxidized over time and the balance of heat generation is lost, or the arrangement is lost due to expansion and contraction of the heating wire, resulting in a heat generation temperature. Differences can occur. As a result, for example, when the temperature near the inner diameter side of the workpiece end surface is about 300 ° C. and the temperature near the outer diameter side is about 500 ° C., the heat generation temperature for the circular workpiece becomes non-uniform and uneven melting of the workpiece occurs. Sometimes. Due to this unevenness of melting, insufficient melting or excessive melting occurs, and as a result, it is difficult to keep the shape of the pipe after joining in a circular shape, or there is a possibility of causing poor welding. In this case, insufficient melting leads to insufficient strength, and excessive melting may cause voids. In particular, when welding a workpiece having a small diameter, these tendencies become more prominent and the unevenness of melting becomes large, and the finished pipe after welding becomes difficult to stabilize. When the heat generating plate is a conductive ceramic plate, it is necessary to make the temperature region longer than the diameter of the workpiece in order to widen the same temperature region when it is a normal strip electrode.

The heater in Patent Document 1 described above can adjust the heat generation temperature by adjusting the spray length of the side surface section electrode. However, this structure is for suppressing heat generation at the terminal part of the electrode part, and the temperature of the heating part for welding the workpiece cannot be adjusted. For this reason, it is difficult to heat and weld the ends of the workpieces in a soaking state.
On the other hand, a heater plate having a thin film electrode, in particular, a heater in which the left and right sides of the heat generating plate are longer than the upper and lower sides can reduce the difference in the heating temperature of the part that heats the workpiece. However, this heater has a demerit that the overall size becomes large. Therefore, with an increase in the size of the heater, an increase in the size of the entire welder is inevitable. In addition, when heating a small-diameter workpiece with an enlarged heater, it becomes difficult to keep the vicinity of the center of the ceramic plate in a soaking state, and since the melting point of the fluororesin is high, a large electric power is required to heat the vicinity of the center of the heater. Is required.

  The present invention has been developed in order to solve the above-mentioned problems, and the object of the present invention is to heat and weld firmly to a predetermined high temperature state even for a small-diameter resin annular workpiece having a high melting point. A resinous annular work melting heater that generates heat in a temperature distribution suitable for the shape of the end face of the annular work and can evenly melt and join them, ensuring the overall compactness and miniaturizing the welder It is to provide a welding machine.

  In order to achieve the above object, an invention according to claim 1 is a melting heater for a resin annular work in which electrodes are provided on both left and right ends of both sides of a heater plate made of a rectangular conductive ceramic, the heater plate This is a melting heater for a resin-made annular workpiece in which the length of the electrode portion applied in the vertical direction is shorter than the vertical length of the heater plate, and the heat generation area of the heater plate has a conical temperature distribution.

  The invention according to claim 2 is a resin in which the length of the electrode portion in the vertical direction is shorter than both ends of the heater plate in the vertical direction, and the length of the electrode portion relative to the length of the heater plate is in the range of 50% to 70%. This is a melting heater for an annular workpiece.

  The invention according to claim 3 is a resin-made annular work melting heater in which electrode portions are provided by aluminum spray deposition on both end portions of both sides of the heater plate.

  The invention according to claim 4 is a resin-made annular work melting heater in which the annular work is a tube made of a fluororesin such as PFA and both end surfaces of the pair of tubes are heated in a soaking state.

  The invention according to claim 5 is the resin-made annular workpiece melting heater, wherein the tube is a tube having an outer diameter corresponding to the size of the A name or B name corresponding to a wall thickness of 1 to 2.2 mm.

  The invention according to claim 6 is a welding machine equipped with a resin-made annular work melting heater and provided so that the annular work can be welded by butt welding.

  According to the first aspect of the present invention, since the length of the electrode portion is shorter than the length of the heater plate in the vertical direction and the heat generating area of the heater plate is formed in a conical temperature distribution, the small-diameter resin ring having a high melting point is formed. Even workpieces can be welded by heating to a high temperature state, and heat can be generated in a temperature distribution suitable for the shape of the end face of the workpiece, so that they can be joined in a state of being evenly melted. In particular, it prevents the occurrence of uneven inner surface beads, secures the flow path by suppressing the reduction of the flow area, prevents the adhesion of pollutants and the generation / reproduction of bacteria and other microbubbles, Can be suppressed. The melting heater of the present invention is particularly suitable for the semiconductor industry field, for example, clears high demands required for semiconductor manufacturing process piping, achieves complete sealing by end face butt welding, and has a sliding part on the inner surface of the connection part. Since there is no particle, the particle characteristics are excellent, and the welded portion has higher strength than other portions. Furthermore, since heat resistance can be ensured and the overall compactness and weight reduction can be ensured, it is effective in reducing piping space and contributes to miniaturization of the welder.

  According to the invention which concerns on Claim 2, the length of the electrode part with respect to the length of a heater plate can be set in a predetermined range, and a workpiece | work end surface can be fuse | melted equally and joined by this electrode part. In addition, by adjusting the length of the electrode part, the accuracy of the temperature distribution of the conical shape of the heat generation area is further improved, the end face of the annular work is melted more evenly on the circumference, and variations in the joined state of the work after joining are achieved. Can be avoided and quality can be improved.

  According to the invention which concerns on Claim 3, the electrode part of predetermined length can be easily formed by carrying out the aluminum spray deposition to the both-ends part of both surfaces of a heater plate. Therefore, it is possible to provide a conical heat generation area by adjusting the size of the electrode part for a heater plate of any shape, and it is possible to ensure uniform heat transfer of the heater plate by the electrode part. become.

  According to the invention according to claim 4, a tube made of a fluororesin such as PFA, which is mainly used in the field of semiconductor manufacturing and has a high melting point and is difficult to weld, can be welded uniformly with high accuracy, and the inner peripheral bead is minimized. It is possible to prevent impurities from being mixed and particles from being generated when supplying the semiconductor manufacturing gas.

  According to the invention which concerns on Claim 5, the ready-made tube which has an outer diameter corresponding to the various sizes of A name or B name corresponding to a thickness of 1-2 mm can be utilized as an annular work, for example, outer diameter φ6 It is suitable for welding a tube of about ~ 39 mm.

  According to the invention of claim 6, it is possible to provide a welding machine that can melt and join the workpieces uniformly, melt the end faces of the annular workpiece by this welding machine, and weld them easily by butt welding, so that the inner surface bead is uniform. A high quality tube can be provided.

It is a perspective view which shows embodiment of the fusion heater for resin-made annular workpieces of this invention. It is a front view which shows the attachment state of a melting heater. It is a schematic side view which shows the attachment state of a melting heater. It is a schematic diagram which shows the heat conduction state of a melting heater. It is a schematic diagram which shows the heat conduction state in the melting heater which extended the electrode part. It is a schematic side view which shows the welding process of a cyclic | annular workpiece | work. It is the schematic which shows a welding machine main body. It is a conceptual diagram which shows a welding machine main body. It is the photograph which showed the thermal image data and temperature distribution analysis result of the melting heater of the electrode part of 60% of heater plate ratios. It is the photograph which showed the thermal image data and temperature distribution analysis result of the fusion | melting heater of the electrode part of 50% of heater plate ratios. It is the photograph which showed the thermal image data and temperature distribution analysis result of the fusion | melting heater of the electrode part of 70% of heater plate ratios. It is the photograph which showed the thermal image data and temperature distribution analysis result of the melting heater of the electrode part of 75% of heater plate ratios. It is the schematic diagram which showed the heat_generation | fever state of the melting heater of this invention. It is the schematic diagram which showed the heat_generation | fever state of the heater of the comparative product. It is the schematic diagram which showed the heat_generation | fever state of the heater of the comparative product.

  Hereinafter, preferred embodiments of a resin-made annular work melting heater and a welding machine according to the present invention will be described in detail with reference to the drawings. In FIG. 1, the perspective view of the melting heater for resin-made annular workpieces of this invention is shown, and in FIG. 2, the attachment state of the melting heater is shown.

  As shown in FIG. 1, the melting heater for resin-made annular workpieces (hereinafter referred to as melting heater) of the present invention has a heater plate 1 and an electrode portion 2. The heater plate 1 is made of a conductive ceramic, and is formed in a rectangular shape with an appropriate thickness. The electrode parts 2 are respectively provided on both ends of the heater plate 1 in the left-right direction on both sides. A through hole 3 penetrating the front and back sides is provided at an arbitrary position on the heater plate 1 where the electrode portion 2 is applied.

  The electrode portion 2 is made of, for example, aluminum, and is applied to both ends of both surfaces of the heater plate 1 by spray deposition. In this case, the electrode portion 2 is provided in the vertical direction of the heater plate 1, and the vertical length L <b> 1 is shorter than the vertical length L <b> 2 of the heater plate 1. As a result, in the heater plate 2, the heat generation region T indicated by the two-dot chain line in FIG. 2 has a conical temperature distribution. The heat generation region T is a region formed in a substantially square portion of the heater plate 1 between the electrode portions 2 by heat conduction when a voltage is applied to the electrode portions 2.

  Here, “the heat generation region T has a conical temperature distribution” means that when the vertical axis and the horizontal axis of the temperature distribution are set at the center of the heater plate 1, the vertical axis and the horizontal axis are respectively peaks. This is the case where the curves become the same and the curves have substantially the same shape. In this case, the central portion of the heater plate 1 has the highest temperature due to the temperature distribution in the vertical direction and the horizontal direction, and a heat generation region T having a conical temperature distribution that gradually decreases in temperature as the distance from the central portion increases. .

  In this embodiment, the length L1 of the electrode part 2 in the vertical direction is made shorter than both ends of the length L2 in the vertical direction of the heater plate 1, and the length L1 of the electrode part is set from the length L2 of the heater plate. Although the length is 60%, the length L1 of the electrode portion 2 with respect to the length L2 of the heater plate 1 can be set in a range of 50% to 70%.

  An extension member 5 is attached to the electrode portion 2, and the extension member 5 is provided in a long shape with a metal material that is excellent in oxidizing properties such as nickel and has a lower thermal expansion coefficient than the electrode portion. One end of the extension member 5 is fixed by a bolt nut 6 through the through hole 3, and the free end is fixed by a bolt nut 6 to a heat insulating material 7 made of an appropriate material. A terminal portion 8 is attached to the other end portion of the extension member 5 by a bolt nut 6, and the electric wire 4 is connected to the terminal portion 8. The electric wire 4 is connected to a power source (not shown), and a voltage can be applied from the electric wire 4 to the electrode portion 2 via the extension member 5 by controlling a welding machine body 20 described later. Thus, by providing the terminal portion 8 at a position separated from the electrode portion 2 via the extending member 5, the terminal portion 8 is prevented from being consumed due to the high temperature of the electrode portion 2. When a voltage is applied to the electrode part 2, it is desirable that the temperature of the heat generating region T of the heater plate 1 is about 500 ° C.

  In addition to using the heater plate 1 in a landscape orientation as shown in FIG. 2, the melting heater can also be used in a orientation in which the heater plate 1 is in a portrait orientation. Arranged above and below the plate 1. Further, the heater plate 1 can be used obliquely, and its direction can be changed as appropriate depending on the mode of the welder main body 20.

  The annular workpiece 10 melted by the melting heater of the present invention shown in FIG. 3 is a tube or pipe made of a fluororesin having thermoplasticity such as PFA or modified PTFE. In this embodiment, a tube having an outer diameter corresponding to the size of the A name or B name corresponding to a wall thickness of 1 to 2.2 mm is used as the annular workpiece 10. For example, as a tube having a size corresponding to the wall thickness of 1 to 2.2 mm, there are a tube having an outer diameter of φ6 to φ25 mm and a tube having an outer diameter of φ1 / 8 to φ1 · 1/2 inch. A tube having an outer diameter of φ6 mm or less, or a tube having an outer diameter of φ1 · 1/2 inch or more can be used as the annular workpiece 10.

Further, the annular workpiece 10 may be other than fluororesin as long as it is a thermoplastic resin. For example, vinylidene chloride, vinyl chloride, vinyl acetate, polyvinyl alcohol, styrene, ABS, polycarbonate, polyethylene, ultrahigh molecular weight polyethylene. , Polypropylene, acrylic, butyrate, acetate, polyamide, polyacetal, AS, and vinylidene fluoride. When the annular workpiece 10 is formed of a fluororesin, it exhibits chemical resistance and heat resistance against chemical fluids and gases such as semiconductor manufacturing fluids flowing through the annular workpiece 10 and prevents generation of particles and has high cleanliness. In this case, it is necessary to increase the temperature for melting.
Any one of these can be used as the annular workpiece 10, and both end surfaces of the pair of tubes 10 and 10 can be welded by heating them to a soaking state with the melting heater.

Then, the welding machine for heating the melting heater of this invention is demonstrated.
7A shows a schematic plan view of the welder main body, and FIG. 7B shows a schematic front view of the welder main body. Moreover, in FIG. 8, the conceptual diagram of the welding machine main body is shown. The main body of the welding machine is equipped with the above-described melting heater, and joins the annular workpieces together by welding.

In the figure, the welding machine main body 20 has a moving mechanism 22, a clamp 32, a stopper 31, a retracting mechanism 23, and a control mechanism 24.
The moving mechanism 22 includes a ball screw 28 and a motor 29, and is attached along the bar-shaped guide portion 30 via the ball screw 28 rotated by the motor 29 so as to advance or retreat. The clamp 32 is provided in the moving mechanism 22 and a portion facing the moving mechanism 22, and the left and right annular workpieces 10, 10 can be attached in an aligned state by the clamp 32. The stopper 31 can be clamped at an arbitrary position while the clamp 32 is moved forward or backward, and the interval between the clamps 32 is adjusted by loosening the stopper 31, and the clamp 32 is fixed at the time of welding operation by tightening. Can be fixed in position.

  The retraction mechanism 23 includes a handle 33 and a heater mounting portion 34, and the above-described melting heater can be mounted on the heater mounting portion 34. The retraction mechanism 23 is attached to the guide portion 30 so as to be able to move laterally and pivotally, and can be finely adjusted in a state of being installed at a fixed position via the guide portion 30, and can be adjusted to any position via the guide portion 30. The melting heater is lifted and arranged between the left and right annular workpieces 10 and 10 held by the clamp 32 by moving the handle 33 manually and rotating, or from between the annular workpieces 10 and 10. The melting heater can be retracted and stored in a storage box (not shown) formed in the welder main body 20. Although not shown, the retraction mechanism 23 can be rotated by an automatic operation mechanism.

The control mechanism 24 includes a process step switch 35 and an operation panel 36. The control mechanism 24 can be operated by turning on the process step switch 35 and controls the operation of the moving mechanism 22 via the operation panel 36 or controls the heating of the melting heater to melt the annular workpieces 10 and 10. It is possible to weld.
The above-described welding machine main body 20 is merely an example, and any welding machine other than the butt welding machine can be used as long as it has a structure capable of welding the annular workpiece 10 by heating the melting heater to a predetermined temperature. Is possible.

  3 and 6, when welding the annular workpieces 10 and 10 using the welding machine main body 20, a heater power switch (not shown) is turned on in advance before welding work to heat the melting heater to an appropriate temperature, The annular work 10 is attached to the clamp 32 in an aligned state, the moving mechanism 22 is adjusted, and the end faces 10a and 10a of the annular work are arranged at appropriate positions with respect to the melting heater. Fix in the positioning state. At this time, it is important that the annular workpiece end surface 10a and the melting heater are in a non-contact state. At this time, if the annular workpiece end surface 10a and the melting heater are too close to each other, the workpiece end surface temperature becomes high and the amount of decomposition gas generated also increases. The gap between the annular workpiece end surface 10a and the melting heater is preferably, for example, about 1.0 to 1.2 mm. In this case, the workpiece end surface temperature is easily heated to around 400 ° C.

The melting heater is always properly controlled in the state set by the operation panel 36, and the applied voltage is applied to the electrode portion 2 through the electric wire 4 and the extension member 5, and the heating region T in FIG. The heater plate 1 generates heat at the center.
In this state, the process step switch 35 is turned on and the annular work end surface 10a is heated and melted for a predetermined time in the heat generation region T of the heater plate 1 while being controlled by the operation panel 36 as shown in FIG. . At this time, since the length of the electrode portion 2 applied in the vertical direction of the heater plate 1 is shorter than the vertical length of the heater plate 1 and the heat generation region T has a conical temperature distribution, the end surface of the annular workpiece The circumference of 10a can be evenly melted. The front and back surfaces of the melting heater have substantially the same heat generation distribution shape, and the temperature in the vicinity of the electrode portion 2 is lower than the center of the heat generation region T due to heat radiation. When the annular work end face 10a portion is melted, for example, the melting depth (melting allowance) of about 0.8 to 1.2 mm from the end face side may be used, and at this time, the entire circumference is easily welded in an appropriate state.

  When the annular workpiece end surface 10a reaches a molten state suitable for welding, the melting heater is retracted from the annular workpiece end surface 10a by operating the handle 33. Subsequently, as shown in FIG. 6C, the moving mechanism 22 is moved in the pressing direction to bring the annular workpiece end faces 10a and 10a into close contact with each other. In this case, while the operation of the moving mechanism 22 is controlled by the control mechanism 24, the annular workpiece end faces 10a and 10a are pressed and pressed to each other at a predetermined distance and speed, and the bonded state is maintained under pressure for a certain time. It can be welded in an appropriate state.

Furthermore, before the pressure is maintained for a certain period of time, for example, using the welding method of Japanese Patent No. 3910567 filed by the present applicant, a process of stretching the melt-bonded tube in the direction opposite to the butting direction may be performed. Good.
Then, the tube of the predetermined shape which can be utilized for a pipe line etc. can be provided by removing the tube joined from the clamp and cooling with appropriate equipment.

  As described above, the resin-made annular work melting heater of the present invention heats the heat generation region T of the heater plate 1 to a conical temperature distribution, so that the temperature on the circumference of the annular work end surface 10a during melting is increased. The annular workpieces 10 and 10 can be uniformly welded in a state in which the variation of the above is eliminated and the melting unevenness is prevented.

  The mechanism in the welding process at this time will be described in detail. In the heater plate 1 which is a conductive ceramic heater, when voltage is applied to both electrode portions 2 and 2, electricity flows linearly to the electrode portion 2. There is a nature. In this case, if the width of the electrode portion 2 is increased, the current area increases, so the amount of heat generation increases, and the entire heater plate 1 generates heat. On the other hand, when the width of the electrode part 2 is reduced from this state, the current area is reduced and the heat generation area is reduced. At that time, the portion of the heater plate 1 where no current flows is heated by heat conduction from the portion where the current is flowing (heated), and the portion near the electrode portion 2 is heated as shown in FIG. Is emitted.

  In the melting heater of the present invention, the shape of the heat generation region T is changed by changing the width of the electrode portion 2 so that a conical temperature distribution suitable for welding the annular workpiece 10 can be formed. In addition, since the vertical length of the electrode portion 2 is in the range of 50% to 70% of the vertical length of the heater plate 1, the end face of the annular workpiece is maintained while keeping the size of the heater plate 1 at the minimum dimension. It can be heated to a temperature that melts 10a.

  Therefore, the melting heater can be made compact, and the welder main body 20 can also be reduced in size. Since the annular workpiece 10 can be welded in an appropriate molten state at the time of welding, the annular workpiece end surface 10a is not excessively melted, and the entire area of the annular workpiece end surface 10a is heated and welded in a soaking state to obtain a substantially uniform thickness. Bead can be formed. At this time, the voltage is applied to the electrode part 2 through the extension member 5, thereby suppressing the secular change due to the deterioration of the terminal part 8 and heating the heater plate 1 to a predetermined temperature distribution over a long period of time. Welding can be performed.

  Furthermore, the inner surface bead can be stretched and the inner surface of the tube can be made smooth by passing through a process of stretching the melt-bonded tube using the welding method of Japanese Patent No. 3910567 in the direction opposite to the butting direction.

  In addition, when the electrode part 11 is extended as shown in FIG. 5 and this electrode part 11 is provided at the same length L3 as the vertical length of the heater plate 1, the vertical direction of the electrode part 11 is Since there is no electrode part, the temperature distribution of the heater plate 1 is substantially constant. However, there is no heat generation in the left-right direction of the electrode part 11, and since the temperature decreases as it approaches the electrode part 11, the temperature decreases from the center of the heater plate 1 toward the electrode part 11. Therefore, the temperature distribution of the heater plate 1 in the vertical direction and the horizontal direction changes extremely, and a heat generation region having a conical temperature distribution cannot be obtained. Therefore, the temperature at which the annular tube end face 10a is melted varies.

Next, a voltage was applied to the resin-made annular workpiece melting heater, and the surface temperature of the heater plate was measured by experiment, and the evaluation was performed.
The vertical length of the heater plate of the melting heater used in this experiment was 50 mm, the horizontal width was 80 mm, and the thickness was 5 mm. On both sides of the heater plate, the left and right widths were 15 mm, and the electrode portions with the vertical lengths of 60%, 50%, 70%, and 75% of the vertical length of the heater plate were provided by aluminum spray deposition. Among these, the heat generation area between the electrode portions of 60% is a substantially square having a side of 50 mm. As for these, the electrode part of both surfaces is connected by the side surface. The melting heater is attached to the above-described welding machine by a clamp, generates heat when a voltage is applied from a power source, and the annular workpiece is heated using a moving mechanism, a retracting mechanism, and a control mechanism.

  These melting heaters are heated by a welding machine while being controlled by a control mechanism so that the central portion of the heater plate is preferably about 500 ° C., and the temperature is stabilized after a predetermined time. The temperature distribution was analyzed. 9 to 12 show thermal image data and temperature distribution analysis on one end side of the heater plate, respectively. These are substantially the same results on the other end side of the heater plate.

In the thermal image data shown in FIGS. 9 (a), 10 (a), 11 (a), and 12 (a), the temperature decreases with increasing distance from the center of the heater plate, and substantially the same temperature portion is annular. Shown in
In the temperature distribution analysis shown in FIG. 9B, FIG. 10B, FIG. 11B, and FIG. 12B, the result of analyzing the temperature distribution in the range from the center of the heater plate to 25 mm in the vertical direction. Is shown. In the temperature distribution analysis shown in FIG. 9C, FIG. 10C, FIG. 11C, and FIG. 12C, the result of analyzing the temperature distribution in the range from the center of the heater plate to 25 mm in the left-right direction. Is shown. By combining these, the temperature distribution in the φ50 mm heat generation region can be analyzed. In the figure, the vertical line indicated by the alternate long and short dash line is the position of the imaginary circle having a diameter of 1 inch from the center of the heater plate, and the vertical line indicated by the two-dot chain line is the imaginary circle having a diameter of 1/4 inch from the center of the heater plate. The vertical lines indicated by the positions and broken lines indicate the positions of virtual circles having a diameter of 11/2 inches from the center of the heater plate. Tubes having a predetermined diameter of these virtual circles are arranged and melted.

  From the results shown in the figure, it was confirmed that the temperature distribution of the melting heater is the highest in the central portion, and gradually decreases as the distance from the central portion decreases. By disposing the thick portion of the annular tube in one temperature region of the melting heater and melting the end face of this thick portion, the end face can be melted in a soaking state, and the inner surface of the annular tube can be welded in a uniform state.

  FIG. 9 shows thermal image data and temperature distribution analysis results of a melting heater in which the vertical length of the electrode portion is set to 60% with respect to the vertical length of the heater plate. In this case, as shown in FIG. 9 (a), the temperature distribution by the thermal image is substantially conical from the center, and as shown in FIGS. 9 (b) and 9 (c), any virtual circle Also in each, the temperatures are substantially equal. Furthermore, the temperature distribution has a substantially conical shape even inside the virtual circle having a diameter of 1 inch.

  FIG. 10 shows thermal image data and temperature distribution analysis results of a melting heater in which the vertical length of the electrode portion is set to 50% with respect to the vertical length of the heater plate. As shown in FIG. 10 (a), the temperature distribution based on the thermal image is a shape in which the cone-shaped heat distribution is slightly crushed sideways, but in FIG. 10 (b) and FIG. 10 (c), Each temperature can be maintained substantially equal even in the virtual circle.

  FIG. 11 shows thermal image data and temperature distribution analysis results of a melting heater in which the vertical length of the electrode portion is set to 70% with respect to the vertical length of the heater plate. As shown in FIG. 11A, the thermal center area is slightly above the heater plate, but the temperature distribution based on the thermal image has a shape close to a conical heat distribution. Therefore, as shown in FIGS. 11 (b) and 11 (c), the end face can be melted with a substantially equal temperature distribution in the case of an annular work having a diameter of about 1 inch.

  FIG. 12 shows thermal image data and temperature distribution analysis results of a melting heater in which the vertical length of the electrode portion is set to 75% with respect to the vertical length of the heater plate. In this case, as shown in FIG. 12A, the heat distribution is vertically long, and it is difficult to maintain the temperature evenly in any virtual circle in FIGS. 12B and 12C. . Therefore, it becomes inappropriate for melting of the annular workpiece.

  From these experimental results, it can be confirmed that the temperature distribution in the heat generation region of the heater plate having the electrode portion with a length of 60% of the heater plate is closest to a conical shape and is particularly effective when melting the annular pipe. It was. As for the length of the electrode portion, about ± 10% centering on 60% of the heater plate ratio is in a range where a heat distribution close to a conical shape is possible, and the length of the electrode portion having such a heater plate ratio of 50% to 70%. It can be said that it is a critical value that can be welded while uniformly melting the annular workpiece.

  From the results in the figure, the temperature distribution of the left and right melting heaters is that the temperature at the center is the highest, and the temperature distribution has a substantially conical shape with the temperature gradually decreasing as the distance from the center is increased. confirmed. As a result, when the annular tube is melted by the melting heater, the end face of the tube can be melted by heating in a uniform temperature state and welded in a uniform molten state.

  Subsequently, the surface temperature of the entire length of the heater plate including the range where the electrode portion was provided in the molten heater having the electrode portion length of 60% of the heater plate ratio was measured by experiments. Moreover, in order to compare with the temperature distribution of this melting heater, comparative products 1 and 2 were provided, and the surface temperature of the entire heater plate was also measured for these comparative products 1 and 2. The heat generation state of the melting heater of the present invention is shown in FIG. 13, and the heat generation states of the heaters of comparative products 1 and 2 are schematically shown in FIGS.

In the comparative product 1 in FIG. 14, the length of the heater plate in the left-right direction is the same as that of the melting heater in FIG. 13, and a substantially square heat generating region is formed between the electrode portions. On the other hand, the length of the electrode portion in the vertical direction is extended to the length of the heater plate in the vertical direction, unlike the melting heater in FIG.
The comparative product 2 in FIG. 15 is formed such that the heater plate in the left-right direction is longer than the melting heater in FIG. 13, and a rectangular heat generating region is formed between the electrode portions. On the other hand, the length of the electrode portion in the vertical direction is the same as that of the melting heater in FIG.

  As a result of measuring these temperature distributions, as shown in the figure, in the melting heater of the present invention, the temperature distribution in the vertical direction and the temperature distribution in the horizontal direction in the central part of the heater plate become a mountain-shaped curve, These became curves of substantially the same shape. From this, it was confirmed that in this melting heater, the heat generation region of the heater plate was formed in a conical temperature distribution.

  On the other hand, in the comparative products 1 and 2, the temperature distribution in the vertical direction and the temperature distribution in the horizontal direction are not substantially the same shape. Specifically, in the comparative product 1, the temperature distribution in the vertical direction is higher on average than the temperature distribution in the horizontal direction, and thus the temperature distribution in the heat generation region does not have a conical shape. In the comparative product 2, the temperature distribution in the vertical direction is lower on average than the temperature distribution in the horizontal direction, and therefore the temperature distribution in the heat generation region does not have a conical shape. In this case, in the left-right direction of the heater plate, the temperature is reduced from about 30 mm from the end of the electrode portion.

From the above results, the length of the electrode portion in the vertical direction is made shorter than both ends in the vertical direction of the heater plate, and the length of the electrode portion is set to 50% to 70%, preferably 60% of the length of the heater plate. It was confirmed that when the heat generation area between the parts was made into a substantially square shape, the heat generation area could have a conical temperature distribution. In this case, the conical temperature distribution becomes a heat distribution suitable for melting the annular workpiece, and the annular workpiece can be uniformly melted and welded.
It is also possible to provide a melting heater other than the dimensions shown in the above embodiments, and the vertical length of the electrode portion is in the range of 50% to 70% of the vertical length of the heater plate, preferably 60. If it is provided in%, it becomes possible to enlarge the whole and melt large-diameter tubes and pipes. In this case, care must be taken because adverse effects are likely to occur as the tube or pipe diameter increases.

  The melting heater for resin-made annular workpieces of the present invention can be used as a melting heater for welding annular workpieces used in various industries other than the semiconductor manufacturing field, and can be used for welding resin workpieces having various thermoplasticity. It becomes possible.

1 Heater plate 2 Electrode part 10 Tube (annular workpiece)
20 Welding Machine Body L1 Vertical Length of Electrode L2 Vertical Length of Heater Plate T Heating Area

Claims (6)

  A resin-made annular work melting heater in which electrodes are provided on both left and right ends of both sides of a heater plate made of a rectangular conductive ceramic, wherein the length of the electrode portion applied in the vertical direction of the heater plate is the heater plate A resin-made annular work melting heater, wherein the heater plate has a heat generation area having a conical temperature distribution formed shorter than the vertical length of the heater plate.   The length of the said electrode part in the up-down direction is made shorter than the up-down direction both ends of a heater plate, The said length of the electrode part with respect to the length of a heater plate was made into the range of 50%-70%. Melting heater for annular workpieces.   The melting heater for resin-made annular workpieces according to claim 1 or 2, wherein electrode portions are applied to both end portions of both sides of the heater plate by aluminum spray deposition.   The melting heater for a resin-made annular workpiece according to any one of claims 1 to 3, wherein the annular workpiece is a tube made of a fluororesin such as PFA and both end surfaces of the pair of tubes are heated in a soaking state.   The molten heater for resin-made annular workpieces according to claim 4, wherein the tube is a tube having an outer diameter corresponding to a size of a name A or a size B corresponding to a wall thickness of 1 to 2.2 mm.   A welding machine equipped with the resin-made annular workpiece melting heater according to any one of claims 1 to 5, wherein the annular workpiece is provided so as to be welded by butt welding.

Images