JP6795189B2 - High-frequency dielectric welding device for stepped tubes and high-frequency dielectric welding method for stepped tubes - Google Patents

Description

The present invention relates to a high-frequency dielectric welding device for stepped tubes using a polymer resin material and a high-frequency dielectric welding method for stepped tubes, and particularly a medical-grade tube having a different diameter or a stepped portion in which tubes having different thicknesses are stacked. The present invention relates to a high-frequency dielectric welding device suitable for welding a stepped portion for attaching a drip tube of a drip container, and a stepped portion where a tube and a joint overlap, and a high-frequency dielectric welding method.

Conventionally, a high-frequency dielectric welding device and a high-frequency dielectric welding method in which a stepped portion in which a pair of different-diameter tubes for medical use are stacked and a stepped portion for attaching a drip tube in a drip container are welded by high-frequency dielectric heating have been used. Are known.
In high-frequency dielectric heating, when a high frequency (high-frequency alternating voltage) is applied to polar plastic, the poles of the plastic molecules continue to invert in response to changes in the polarity of the high frequency, and the molecular movement becomes active and heat is generated. A thermoplastic resin such as vinyl chloride (PVC) is a suitable material. Then, as shown in FIGS. 14 and 17, the thermoplastic resin is actually welded by high-frequency dielectric heating (see, for example, Patent Document 1).

In FIG. 14, the left end of the first tube 21 is covered with the second tube 22, and the outer periphery of the second tube 22 has a block-shaped or plate-shaped shape, respectively, and can be freely divided and combined into upper and lower parts of the paper surface. The first electrodes 23a and 23b, the insulating plates 24a and 24b, and the second, each of which has a semicircular notch in cross section that receives the first tube 21 and the second tube 22 and adheres to the first tube 21 and the second tube 22. The electrodes 25a and 25b are applied, and the first electrodes 23a and 23b and the second electrodes 25a and 25b are connected to the high frequency power supply 26. Incidentally, in the high frequency power supply 26, for example, a high frequency current of 10 MHz to 40 MHz is applied to the first electrodes 23a and 23b and the second electrodes 25a and 25b.

In FIG. 14, when a high-frequency current in which the positive electrode and the negative electrode alternate at high frequencies is passed between the first electrodes 23a and 23b and the second electrodes 25a and 25b by the high-frequency power supply 26, one electrode alternates with the other electrode. High frequency voltage is applied to. Then, the molecular poles of the first tube 21 and the second tube 22 inside the notches of the insulating plates 24a and 24b continue to be inverted as shown by the dotted lines with arrows at both ends in FIG.

In the first tube 21 and the second tube 22 near the insulating plates 24a and 24b, the molecules of the first tube 21 and the second tube 22 repeatedly invert the polarities of the positive electrode and the negative electrode due to the dielectric action of the high frequency current to generate heat. Then, the hatched region 29 shown by the dotted line in FIG. 15 melts. When the high-frequency power supply 26 is turned off, the hatched regions 29 of the first tube 21 and the second tube 22 cool, solidify, and weld.

In FIG. 14, the image in which the poles of the plastic molecule are inverted is shown by three dotted lines with arrows at both ends. The poles of the plastic molecule are inverted in the part near the surface where the first and second electrodes of the first tube 21 and the second tube 22 are in contact with each other, but the part away from the first and second electrodes is the plastic molecule. The pole is hard to reverse. Therefore, if the wall thickness of the second tube 22 or the wall thickness of the first tube 21 and the second tube 22 is thick, from the surface where the first and second electrodes are in contact with the first tube 21 and the second tube 22. The amount of heat generated is reduced at a distance.

In an extreme case, the second tube 22 in the vicinity where the first electrodes 23a and 23b and the second electrodes 25a and 25b are in contact with each other generates heat, melts and solidifies, but the first electrodes 23a and 23b and the second electrodes 25a and 25b The first tube 21 away from the above does not generate heat or melt, and the contacted portion between the first tube 21 and the second tube 22 may not be welded. For this reason, the conventional high-frequency dielectric welding apparatus has a problem that the wall thickness of the tube that can be welded, particularly the wall thickness of the second tube is thin.

Further, in Patent Document 1, as shown in FIGS. 16 and 17, a tube 32 is provided at the end of the drip container 31, a stepped joint 37 is welded to the tube 32, and a drip tube is attached to the stepped joint 37. An example is shown in which the 38 is fitted. In this conventional example, as shown in FIG. 17 with a schematic cross section of the high-frequency dielectric welding device, the end surface 32a of the tube 32 and the end surface of the stepped portion of the stepped joint 37 are butted against each other, and the outer periphery thereof is directed toward the paper surface. The first electrodes 33a and 33b, which can be split and combined vertically, the insulating plates 34a and 34b, and the second electrodes 35a and 35b are applied, and a high frequency voltage is applied from the high frequency power supply 36.

When the high-frequency power supply 36 is energized with the welded electrodes shown in FIG. 17, the inside of the notch of the insulating plate 34 is alternately formed between the first electrodes 33a and 33b and the second electrodes 35a and 35b in FIG. A high frequency voltage is applied as shown by the dotted line with arrows on both ends, and the electrodes of the plastic molecules are inverted. 18A and 18B are enlarged views showing the E portion of FIG. 17 in an enlarged manner for understanding the invention. In FIG. 17, an image showing the direction in which the poles of the plastic molecule are inverted is shown by three dotted lines with arrows at both ends. However, in FIGS. 18A and 18B, the poles of the plastic molecule are shown by taking one dotted line with an arrow as an example. It is a diagram showing which member the direction of is reversed from which member to which member.

That is, when a high-frequency voltage is applied between the first electrode 33a and the second electrode 35a by the high-frequency power supply device 36, as shown in FIG. 18A, (S) the pole of the plastic molecule from the first electrode 33a to the stepped joint 37. (T) The pole of the plastic molecule points from the stepped joint 37 directly under the insulating plate 34a to the tube 32 in the axial direction of the tube, and (U) the pole of the plastic molecule goes from the tube 32 to the second electrode 35a. Is suitable. Next, as shown in FIG. 18B, the poles of the plastic molecules are reversed in the opposite direction, and (U') from the second electrode 35a to the tube 32, and (T') from the tube 32 directly below the insulating plate 34a to the stepped joint 37. The poles of the plastic molecules point in the axial direction of the tube and from the (S') stepped joint 37 to the first electrode 33a. After that, the poles of the plastic molecules continue to invert in response to changes in high-frequency polarity.

Then, in the stepped joint 37 and the tube 32, the molecules repeatedly invert the polarity in the axial direction of the tube to generate heat and melt. When the energization of the high-frequency current is stopped, the portion where the stepped joint 37 and the tube 32 are abutted is solidified and welded as shown by the dotted lines in FIG. 19 as shown in the regions 39a and 39b.
In the stepped joint 37 and the tube 32, the poles of the plastic molecules are reversed near the surface where the first and second electrodes are in contact, but the parts away from the first and second electrodes are the plastic molecules. The poles are hard to reverse. Therefore, plastic molecules generate heat in the portion where the end face of the stepped portion of the stepped joint 37 and the end face of the tube 32 are butted, but the amount of heat generated in the portion where the tube 32 and the stepped joint 37 overlap in the radial direction. decrease. Therefore, in the example of FIG. 17, the end surface of the partial tube 32 near the surface where the first and second electrodes are in contact and the end surface of the stepped portion of the stepped joint 37 are welded to the butt surface and the vicinity portion where they are abutted. I try to get the required strength.

By the way, FIG. 19A shows a cross-sectional view when the tube 32 and the stepped joint 37 are welded, and FIG. 19B shows a state in which another tube 38 is fitted to the other end of the stepped joint 37 welded to the tube 32. There is. Since the shape of the end face of the stepped joint 37 on the side where the other tube 38 is fitted is not deformed, the other tube 38 and the end face of the stepped joint 37 can be in good contact with each other.

JP-A-60-1495

The present invention relates to a high-frequency dielectric welding device for stepped tubes using a polymer resin material and a high-frequency dielectric welding method for stepped tubes, and particularly a medical-grade tube having a different diameter or a stepped portion in which tubes having different thicknesses are stacked. To provide a new high-frequency dielectric welding device and a new high-frequency dielectric welding method suitable for welding a stepped portion for attaching a drip tube of a drip container, and other stepped portions where a tube and a joint overlap. That is the issue.

More specifically, the present invention is a new step in which high-frequency dielectric welding is reliably performed in the radial direction of the tube while maintaining the shape of the stepped portion where the tubes are stacked and the stepped portion where the tube and the joint are overlapped. An object of the present invention is to provide a high-frequency dielectric welding device for a tube with a stepped tube and a new high-frequency dielectric welding method for a stepped tube.

Each is made of a polymer resin material, and is a high-frequency dielectric welding device in which one end of a small-diameter first tube is fitted into a large-diameter second tube and the overlapping ends of the first and second tubes are high-frequency dielectric welded. The first electrode having a pressing surface for applying a high frequency voltage by pressing the outer peripheral surface near one end of the first tube and the outer peripheral surface of the overlapping end of the second tube are pressed to apply a high frequency voltage. An insulating plate that is interposed between the second electrode having a pressing surface and the first and second electrodes to electrically insulate the first and second electrodes, and when the first and second tubes are overlapped. An insulating plate having a side surface attached in contact with the entire surface of the end surface of the second tube formed in a stepped manner and a pressing surface for pressing the outer peripheral surface near one end of the first tube, the first electrode and the first A high-frequency power supply for applying a high-frequency voltage between the two electrodes is provided, and when a high-frequency voltage is applied between the first electrode and the second electrode by the high-frequency power supply, the insulating plate is used to connect the second tube to the end face. The high frequency voltage applied between the first electrode and the second electrode is blocked, and the high frequency is generated between the first electrode and the second electrode, in the overlapping ends of the first and second tubes, and between the first electrode and the second electrode. It is configured to apply a voltage, and heat is generated and melted by the dielectric action that reverses the polarity of the molecules of the first tube and the second tube, and after the first tube and the second tube are fused with each other, they are cooled and solidified to each other. The region to be welded is formed.

According to the present invention, high-frequency dielectric welding can be reliably performed in the radial direction of the tube while maintaining the shape of the stepped portion in which the tubes are stacked and the stepped portion in which the tube and the joint overlap.
As an incidental effect of the present invention, even when the wall thickness of the second tube or the wall thickness of the first tube and the second tube is thick, the stepped portion where the first tube and the second tube are overlapped is placed in the radial direction of the tube. It can be dielectric welded.

The present invention is not limited to welding thin tubes to each other, and a stepped tube that enables welding and connection between thick tubes or between a thick tube and a thin tube without using a stepped joint. High frequency dielectric welding apparatus and stepped tube high frequency dielectric welding method can be provided.
Further, in the present invention using the split type electrode, it is not necessary to pass the electrode through the tube, so that the tact time of the welding work can be shortened.

The cross-sectional view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 1 of this invention. The left side view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 1 of this invention. The lower electrode portion and the upper electrode portion of the high-frequency dielectric welding apparatus according to the first embodiment of the present invention are separated from each other, and the first tube and the second tube in which a part is overlapped between them are shown to show their positional relationship with each other. Disassembled sectional view. FIG. 5 is a diagram showing a state in which a high-frequency dielectric welding device according to a first embodiment of the present invention is applied with a high-frequency voltage by bringing the upper electrode and the lower electrode into contact with the upper and lower outer peripheral surfaces of the stepped tube. The enlarged view of the D part of FIG. 4 of the high frequency dielectric welding apparatus which concerns on Embodiment 1 of this invention. It is an enlarged view of the D part of FIG. 4 of the high frequency dielectric welding apparatus which concerns on Embodiment 1 of this invention, and is the figure which showed another voltage application state. FIG. 3 is a cross-sectional view of a stepped tube welded by the high-frequency dielectric welding apparatus according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which another tube is fitted into a stepped tube welded by the high-frequency dielectric welding device according to the first embodiment of the present invention. The figure shown. A modified example of the high-frequency dielectric welding apparatus according to the first embodiment of the present invention is shown, and a similar enlarged view corresponding to the D portion of FIG. Another modified example of the high frequency dielectric welding apparatus according to the first embodiment of the present invention is shown, and a similar enlarged view corresponding to the D portion of FIG. The cross-sectional view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 2 of this invention. FIG. 3 is a cross-sectional view of a tube subjected to high-frequency dielectric welding in the high-frequency dielectric welding apparatus according to the second embodiment of the present invention. The cross-sectional view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 3 of this invention. FIG. 3 is a cross-sectional view of a tube subjected to high-frequency dielectric welding in the high-frequency dielectric welding apparatus according to the third embodiment of the present invention. The cross-sectional view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 4 of this invention. The cross-sectional view which showed the schematic structure of the high frequency dielectric welding apparatus which concerns on Embodiment 5 of this invention. The figure which showed the state which the upper electrode and the lower electrode were brought into contact with the upper and lower outer peripheral surfaces of a stepped tube, respectively, and the high frequency voltage was applied in the conventional high frequency dielectric welding apparatus. The figure which showed the cross section of the stepped tube which was high-frequency dielectric welded in the conventional high-frequency dielectric welding apparatus. An exploded perspective view showing the positional relationship between a conventional drip container, a stepped joint, and a drip tube. In a conventional high-frequency dielectric welding device, the first electrode and the second electrode are brought into contact with the upper and lower outer peripheral surfaces of the drip container end tube and the upper and lower outer peripheral surfaces of the stepped joint, respectively, and a high-frequency voltage is applied. The figure shown. The enlarged view of the E part of FIG. 17 of the conventional high frequency dielectric welding apparatus. It is an enlarged view of the E part of FIG. 17 of the conventional high-frequency dielectric welding apparatus, and is the figure which showed another voltage application state. The figure which showed the cross section of the stepped tube which was high-frequency dielectric welded in the conventional high-frequency dielectric welding apparatus. A cross-sectional view showing a state in which another tube is fitted into a stepped tube which has been subjected to high-frequency dielectric welding in a conventional high-frequency dielectric welding device.

(Embodiment 1)
In the first embodiment, one end of a first tube having a small outer diameter, in other words, a thin first tube, has an inner diameter substantially the same as that of the first tube, and an outer diameter larger than that of the first tube, in other words, a thick second tube. The overlapping end of the stepped tube is taken as an example of a stepped tube in which the ends of both tubes are overlapped with each other and the end surface of the second tube formed at the overlapping end is used as the end surface of the step. A high-frequency dielectric welding device that performs high-frequency dielectric welding in the radial direction of the tube will be described.

FIG. 1 is a cross-sectional view showing a schematic configuration of a high-frequency dielectric welding device according to the first embodiment, and FIG. 2 is a left side view showing a schematic configuration of the high-frequency dielectric welding device according to the first embodiment.
As shown in FIG. 1, the high-frequency dielectric welding device according to the first embodiment is a high-frequency dielectric welding device that performs high-frequency dielectric welding of a stepped tube in which a second tube 2 is superposed on one end of a thin first tube 1. In the first embodiment, a split block type electrode and a split type insulating plate which are divided into upper and lower parts in the drawing are used, and a tube is closely attached to the mating surface of each electrode and the insulating plate as described in detail later. A notch (pressing surface) for accommodating is formed.

More specifically, in the welding device of the first embodiment, the first electrodes 3a and 3b having pressing surfaces 3a1 and 3b1 for pressing the outer peripheral surface of the thin first tube 1 and the outer peripheral surface of the same thin first tube 1 are provided. The second electrodes 5a and 5b having the insulating plates 4a and 4b having an L-shaped cross section and the pressing surfaces 5a1 and 5b1 for pressing the outer peripheral surfaces of the second tube 2, respectively, having the pressing surfaces 4a1 and 4b1 for pressing. I have. In the insulating plates 4a and 4b, the entire surface of the end surface 2a of the second tube 2 is brought into contact with the side surfaces 4a2 and 4b2, respectively, and the feeding plate 6 and the feeding terminal portion 6a are arranged above the second electrode 5a in FIG. , The ground plate 7 is arranged below the first electrode 3b. Then, the insulating plates 4a and 4b having an L-shaped cross section are arranged so that the horizontal portions of the L-shape are extended to the opposite sides, and the insulating plate 4a insulates the feeding plate 6 and the first electrodes 3a and 3b. The insulating plate 4b insulates the ground plate 7 and the second electrodes 5a and 5b.

Then, the first electrodes 3a and 3b and the second electrodes 5a and 5b are divided in the vertical direction and can be combined freely, and the first electrodes 3a and 3b are electrically connected by the connecting plate 3c shown in FIG. The second electrodes 5a and 5b are electrically connected by the connection plate 5c shown in 1. That is, the first electrodes 3a and 3b are electrically connected to the ground plate 7, and the second electrodes 5a and 5b are electrically connected to the feeding plate 6. Then, the high frequency power supply device P is connected to the power supply plate 6 and the ground plate 7. The plus (+) and minus (-) symbols in FIG. 1 are shown as symbols indicating a positive electrode and a negative electrode for understanding the invention.

The outer and inner diameters of the tip of the second tube 2 are the same as those of the other tubes 10 fitted in the thin first tube 1 as shown in FIGS. 6A and 6B described later. The end surface 2a at the tip of the second tube 2 is finished to be a flat surface that abuts on the side surfaces 4a2, 4b2 of the insulating plates 4a and 4b and the end surface 10a of another tube 10.
FIG. 3 shows a first tube and a second tube in which the lower electrode portion and the upper electrode portion of the high-frequency dielectric welding apparatus according to the first embodiment of the present invention are separated from each other and a part thereof is overlapped between them. It is an exploded sectional view which showed the positional relationship.

When starting the welding work, one end of the first tube 1 is fitted into the second tube 2 on the lower electrode portion, and a stepped tube on which these are stacked is placed as shown by the arrow A, and the upper electrode portion is indicated by the arrow B. The lower electrode portion and the upper electrode portion are integrally combined with each other. At this time, the pressing surface of each electrode presses the outer peripheral surfaces of the tubes 1 and 2, and the electrodes are attached so as to be in close contact with the outer peripheral surface of the tube so that uniform welding performance of the tube overlapping portion is ensured. There is. After assembling the electrodes in this way, a high frequency voltage is applied from the high frequency power supply device P to the power supply plate 6 and the ground plate 7.

FIG. 4 shows a high-frequency dielectric welding device according to the first embodiment of the present invention, in which the upper electrode portion and the lower electrode portion are brought into contact with the upper and lower outer peripheral surfaces of the stepped tube, respectively, and a high-frequency current is applied. It is a figure shown. 5A and 5B are enlarged views showing the D portion of FIG. 4 of the high-frequency dielectric welding apparatus according to the first embodiment of the present invention in an enlarged manner for understanding the invention. 5A and 5B show the directions in which the high frequency voltage is applied in the opposite directions, and show that the polarities are alternately reversed depending on the timing. In FIG. 4, an image showing the direction in which the poles of the plastic molecule are inverted is shown by three dotted arrows, but in FIGS. 5A and 5B, the poles of the plastic molecule are taken as an example of a dotted line with one arrow. It was explained which member the direction of is reversed from which member to which member.

When a high-frequency voltage is applied between the feeding plate 6 and the ground plate 7 by the high-frequency power supply device P, (a) the poles of the plastic molecules are oriented from the first electrode 3a to the first tube 1 as shown in FIG. 5A. b) The pole of the plastic molecule is oriented in the axial direction of the tube in the first tube 1 directly under the insulating plate 4a, and (c) the pole of the plastic molecule is oriented in the radial direction of the tube from the first tube 1 to the second tube 2. Orientation, (d) The pole of the plastic molecule is oriented from the second tube 2 to the second electrode 5a. Then, as shown in FIG. 5B, the poles of the plastic molecules are reversed in the opposite direction, and (d') the radius of the tube from the second electrode 5a to the second tube 2 and (c') from the second tube 2 to the first tube 1. In the direction, (b') the first tube 1 just below the insulating plate 4 points in the axial direction of the tube, and (a') the pole of the plastic molecule points from the first tube 1 to the first electrode 3a. After that, the poles of the plastic molecules continue to invert in response to changes in high-frequency polarity.

Then, due to the dielectric action of the high-frequency current, the molecules inside the first tube 1 and the second tube 2 repeatedly invert the polarities of the positive electrode and the negative electrode to generate heat and melt.
When the high-frequency current is turned off, the radial portions of the first tube 1 and the second tube 2 are solidified and welded as shown by the dotted lines in FIGS. 6A and 6B. ..

In the present invention, when a high frequency voltage is applied between the first electrode and the second electrode by a high frequency power supply, the insulating plate blocks the high frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube. And to apply a high frequency voltage between the first and second electrodes in the radial direction within the overlapping ends of the first and second tubes between the first and second electrodes. There is a feature.

According to the present invention, the outer peripheral surface 1b at the tip of the first tube 1 is pressed by the pressing surfaces of the first electrodes 3a and 3b so that the entire circumference is uniformly in contact with the outer peripheral surface 1b, and the cylindrical shape is maintained. The end surface 2a at the tip of 2 is in contact with the insulating plates 4a and 4b to maintain a flat surface, and the outer peripheral surface 2b at the tip of the second tube 2 is in contact with the second electrodes 5a and 5b to maintain a cylindrical shape. The original shape is maintained without deformation even when heated during welding.

From the right side of FIG. 6A, when the other tube 10 shown by the alternate long and short dash line is fitted into the first tube 1 and pushed in the axial direction, the end surface 10b of the tube 10 becomes the second tube 10 as shown in FIG. 6B. It abuts on the flat surface of the tip surface 2a of the tube 2.
According to the present invention, since the outer peripheral surface and the end surface of the tube are dielectrically welded while being restrained by the electrodes and the insulating plate, deformation of the outer shape of the stepped portion is prevented. Since the outer peripheral surface 1b of the first tube is prevented from being deformed by heating during welding, the outer shape of the stepped portion and the other tube 10 can be satisfactorily bonded to each other.

To reiterate, according to the present invention, a high frequency voltage is applied in the radial direction of the tube at the portion of the first tube 1 and the second tube 2 that overlap in the radial direction (overlapping end portion). Due to the dielectric action of the high-frequency current, the molecules inside the first tube 1 and the second tube 2 repeatedly invert the polarities of the positive electrode and the negative electrode to generate heat and melt them, and weld them to each other.
Then, it is possible to weld with a predetermined strength regardless of the thickness of the first tube 1 and the second tube 2.

Further, the shapes of the stepped portions of the first tube 1 and the second tube 2 are not deformed.
In the first embodiment of the present invention, the first electrodes 3a and 3b and the pressing surfaces of the insulating plates 4a and 4b are brought into contact with the outer peripheral surface 1b of the first tube 1 so as to be on the side surfaces of the insulating plates 4a and 4b. The requirement is that the end surface 2a of the second tube 2 is brought into contact with the entire surface and the pressing surface of the second electrode is brought into contact with the outer peripheral surface 2b of the second tube. The diameter of the outer circumference of the tube and the diameter of the outer circumference of the first tube to which the pressing surface of the insulating plate abuts may be the same, or high-frequency dielectric welding according to the first embodiment of the present invention in FIGS. 7A and 7B. It may be different as in the modified example of the device.

In FIG. 7A, the diameter of the outer circumference of the first tube with which the pressing surface of the first electrode abuts is larger than the diameter of the outer circumference of the first tube with which the pressing surface of the insulating plate abuts. The diameter of the outer circumference of the first tube that abuts is smaller than the diameter of the outer circumference of the first tube that the pressing surface of the insulating plate abuts, but even if the diameter of the outer circumference of the first tube changes in the middle, the high frequency current This is because the flow method is the same as that in FIGS. 5A and 5B.

Further, the present invention uses a split type electrode. Therefore, it is not necessary to pass the electrode through the tube before dielectric welding and remove the electrode from the tube after dielectric welding, so that the tact time of the welding operation can be shortened.
(Embodiment 2)
In the second embodiment, the shape of the outer peripheral surface on the tip end side of the second tube 12 is a conical trapezoid whose radius gradually decreases toward the front. FIG. 8 is a cross-sectional view showing a schematic configuration of a high-frequency dielectric welding apparatus according to a second embodiment of the present invention. In the figure, components, members, parts, etc. similar to those of the first embodiment described above, which can be easily inferred from the action and effect, are designated by the same reference numerals and the description thereof will be omitted. The same applies below).

In FIG. 8, the tip portion 12b of the second tube 12 is tapered like a truncated cone, and the outer diameter of the tip is the same as the outer diameter of the other tube 13 fitted in the thin first tube 1. The tip surface 12a of the second tube 12 is finished to be a flat surface that abuts on the side surface of the insulating plate 4a and the end surface 13a of the other tube 13.
In FIG. 8, when a high-frequency voltage is applied to the first electrodes 3a and 3b and the second electrodes 5c and 5d from a high-frequency power source P (not shown), the poles of the plastic molecules are oriented from the first electrodes 3a and 3b to the first tube 1. Then, the poles of the plastic molecules are oriented in the axial direction of the tube in the first tube 1 directly under the insulating plates 4a and 4b, and when passing directly under the insulating plates 4a and 4b, the tube is transferred from the first tube 1 to the second tube 12. The poles of the plastic molecules are oriented in the radial direction, and then the poles of the plastic molecules are oriented from the second tube 12 to the second electrodes 5c and 5d. Then, the poles of the plastic molecules are reversed in the opposite direction, from the second electrodes 5c and 5d to the second tube 12, and from the second tube 12 to the first tube 1 in the radial direction of the tube, directly under the insulating plates 4a and 4b. The poles of the plastic molecules face from the first tube 1 to the first electrodes 3a and 3b. After that, the poles of the plastic molecules continue to invert in response to changes in high-frequency polarity.

Then, due to the dielectric action of the high-frequency current, the molecules inside the first tube 1 and the second tube 12 repeatedly invert the polarities of the positive electrode and the negative electrode to generate heat and melt. When the energization of the high-frequency current is stopped and the application of the high-frequency voltage is stopped, the portion where the first tube 1 and the second tube 12 overlap is solidified and welded as shown by the hatched area 9a shown by the dotted line in FIG.
Also in the second embodiment of the present invention, when a high frequency voltage is applied between the first electrode and the second electrode by a high frequency power supply, the high frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube by the insulating plate. And to apply a high frequency voltage between the first and second electrodes in the radial direction within the overlapping ends of the first and second tubes between the first and second electrodes. This is the same as in the first embodiment.

Note that FIG. 9 is a cross-sectional view of a tube high-frequency dielectric welded by the high-frequency dielectric welding device according to the second embodiment of the present invention. According to the second embodiment of the present invention, as shown in FIG. The outer peripheral surface 12b of the tip of the second tube 12 is in contact with the second electrodes 5c and 5d to maintain a conical shape, and the end surface 12a of the tip is in contact with the insulating plates 4a and 4b to maintain a flat surface. The outer peripheral surface 1b of the tube 1 is in contact with the first electrodes 3a and 3b to maintain a cylindrical shape, and the original shape is maintained without being deformed despite the heating of dielectric welding.

From the right side of FIG. 9, when the other tube 13 shown by the virtual line of the alternate long and short dash line is fitted into the outer peripheral edge 1b of the end portion of the first tube 1 and pushed in the axial direction, the end surface 13a of the tube 13 becomes the second tube 12. It abuts on the flat surface of the tip surface 12a. Since the outer shape of the stepped portion is not deformed even by dielectric welding, the outer shape of the stepped portion and the other tube 13 are in good contact with each other.
In the second embodiment of the present invention, the tip of the second tube 12 is tapered in a truncated cone shape, and the outer diameter of the tip 12a is the same as the outer diameter of the other tube 13 fitted in the thin first tube 1. Therefore, there is an advantage that the outer shape of the tube changes smoothly, it looks beautiful, and it bends flexibly even when a bending force is applied.
(Embodiment 3)
In the third embodiment, the shape of the outer peripheral surface on the tip end side of the second tube 14 is formed so that the radius gradually decreases toward the tip, that is, a shape in which cylinders are stacked. FIG. 10 is a cross-sectional view showing a schematic configuration of a high-frequency dielectric welding apparatus according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view of a high-frequency dielectric welded tube in the high-frequency dielectric welding device according to the third embodiment of the present invention.

In FIG. 10, the tip of the second tube 14 is gradually tapered, and the outer diameter at the tip 14a is the same as the outer diameter of the other tube 13 fitted to the outer peripheral surface 1b of the thin first tube 1. There is. Therefore, the tip surface 14a of the second tube 14 comes into contact with the surface of the insulating plate 4a.
In FIG. 10, when a high-frequency voltage is applied from a high-frequency power source P (not shown), the poles of the plastic molecules are oriented from the first electrodes 3a and 3b to the first tube 1, and the first tube 1 directly below the insulating plates 4a and 4b. The pole of the plastic molecule faces in the axial direction of the tube, and when passing directly under the insulating plates 4a and 4b, the pole of the plastic molecule points in the radial direction from the first tube 1 to the second tube 14, and then the second tube 14 The pole of the plastic molecule points from to the second electrodes 5e and 5f.

Then, the poles of the plastic molecules are inverted in the opposite direction, and pass through the insulating plates 4a and 4b in the radial direction from the second electrodes 5e and 5f to the second tube 14 and from the second tube 14 to the first tube 1. , The poles of the plastic molecules face from the first tube 1 to the first electrodes 3a and 3b. After that, the poles of the plastic molecules continue to invert in response to changes in high-frequency polarity.
Then, due to the dielectric action of the high-frequency current, the molecules inside the first tube 1 and the second tube 14 are repeatedly reversed in polarity and melted. When the energization of the high-frequency current is stopped and the application of the high-frequency voltage is stopped, the overlapping portion of the first tube 1 and the second tube 14 is solidified and welded as shown by the hatched area 9b shown by the dotted line in FIG.

Also in the third embodiment of the present invention, when a high frequency voltage is applied between the first electrode and the second electrode by a high frequency power supply, the high frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube by the insulating plate. And to apply a high frequency voltage between the first and second electrodes in the radial direction within the overlapping ends of the first and second tubes between the first and second electrodes. This is the same as in the first embodiment.

In the third embodiment of the present invention, the outer peripheral surface 14b of the tip of the second tube 14 is in contact with the second electrodes 5e and 5f to maintain a cylindrical shape, and the end face 14a of the tip is in contact with the insulating plates 4a and 4b. The flat surface is maintained, and the outer peripheral surface 1b of the first tube 1 is in contact with the first electrodes 3a and 3b to maintain a cylindrical shape. As a result, the original shape is kept unchanged.
From the right side of FIG. 11, when the other tube 13 shown by the alternate long and short dash line is fitted into the first tube 1 and pushed in the axial direction, the end surface 13a of the tube 13 becomes the plane of the tip surface 14a of the second tube 14. Contact. Since the outer shape of the stepped portion is not deformed even by dielectric welding, the outer shape of the stepped portion and the other tube 13 are in good contact with each other.

In the third embodiment of the present invention, the tip of the second tube 14 is gradually tapered, and the outer diameter of the tip is the same as the outer diameter of the other tube 13 fitted in the thin first tube 1. Therefore, there is an advantage that the outer shape of the tube changes stepwise and bends flexibly even when a bending force is applied.
(Embodiment 4)
Although not shown in the above embodiment, according to the present invention, when forming the stepped portion for attaching the drip tube of the drip container, a straight tube is used instead of the stepped joint and welded to the drip container. Can also be formed.

FIG. 12 is a schematic cross-sectional view of a high-frequency dielectric welding device for forming a stepped portion for attaching a drip tube of a drip container, which shows the fourth embodiment of the present invention. The pressing surfaces of the first electrodes 33a and 33b and the pressing surfaces of the insulating plates 34a and 34b are brought into contact with the outer peripheral surface of the first tube 11, and the side surfaces of the insulating plates 34a and 34b are brought into contact with the end surfaces of the tube 32 of the drip container. The pressing surface of the second electrodes 35a and 35b is brought into contact with the outer peripheral surface of the tube 32 of the drip container, and a high frequency voltage is applied from the high frequency power source 36 to the first electrodes 33a and 33b and the second electrodes 35a and 35b. One tube 11 and the tube 32 of the drip container are melted, the application of high frequency voltage is stopped, and the overlapping portion of the first tube 11 and the tube 32 of the drip container is welded in the radial direction of the tube.

In the fourth embodiment of the present invention, the outer shape of the stepped portion is not deformed even if dielectric welding is performed without using the stepped joint as in the conventional example shown in FIGS. 16 and 17, so that the outer shape of the stepped portion is not deformed. And the other tube 38 are in good contact with each other.
(Embodiment 5)
As the fifth embodiment, a high-frequency dielectric welding device that dielectrically welds a range of a certain length in the axial direction from the stepped portion of the stepped tube will be described.

FIG. 13 shows a schematic cross-sectional view of a main part of a high-frequency dielectric welding device that dielectrically welds a range of a certain length in the axial direction from the stepped portion of the stepped tube of the fifth embodiment of the present invention. In FIG. 13, in addition to the first electrodes 3a and 3b, the insulating plates 4a and 4b, the second electrodes 5a and 5b described in the first to fourth embodiments, the second insulating plate is to the left of the second electrodes 5a and 5b. The 4c, 4d, the third electrode 3c, 3d, the third insulating plate 4e, 4f, and the fourth electrode 5c, 5d are overlapped in the axial direction of the tube.

In FIG. 13, the end surface of the second tube 2 is brought into contact with the side surfaces of the insulating plates 4a and 4b in the same manner as in the first to fourth embodiments, but the outer peripheral 1b of the thin first tube 1 is pressed. There are only the first electrodes 3a and 3b and the insulating plates 4a and 4b, the second electrodes 5a and 5b, the second insulating plates 4c and 4d, the third electrodes 3c and 3d, and the third insulating plates 4e and 4f. The fourth electrodes 5c and 5d press the outer circumference 2b of the thick second tube 2.

The first electrodes 3a and 3b and the third electrodes 3c and 3d are electrically connected by the connecting member 3e, and the second electrodes 5a and 5b and the fourth electrodes 5c and 5d are electrically connected by the connecting member 5e. There is. As a result, from the high-frequency power supply device P to the feeding unit 6a, the feeding plate 6, the fourth electrode 5c, 5d, the third electrode 3c, 3d, the second electrode 5a, 5b, the first electrode 3a, 3b, and the ground plate 7. , And the high frequency voltage is applied in the opposite direction.

Since the first electrodes 3a and 3b and the insulating plates 4a and 4b press the outer peripheral 1b of the thin first tube 1 at the stepped portion of the stepped tube, a high frequency is generated in the radial direction of the first tube 1 and the second tube 2. The fact that a voltage is applied and the overlapping contact surfaces of the first tube 1 and the second tube 2 generate dielectric heat and weld to each other is the same as described in the first to fourth embodiments.
In the fifth embodiment, in addition to the above, a high frequency voltage is applied between the second electrode 5a and 5b and the third electrode 3c and 3d, and also between the third electrode 3c and 3d and the fourth electrode 5c and 5d. There is. Therefore, in the axial direction of the tubes, between the second electrodes 5a and 5b and the third electrodes 3c and 3d, and between the third electrodes 3c and 3d and the fourth electrodes 5c and 5d, the first tube 1 and the second tube 2 A high frequency voltage is applied in the radial direction of.

When a high-frequency voltage is applied between the second electrodes 5a and 5b and the third electrodes 3c and 3d, and also between the third electrodes 3c and 3d and the fourth electrodes 5c and 5d, the second electrode and the second electrode are arranged in the axial direction of the tube. Dielectric welding is performed between the third electrode and between the third electrode and the fourth electrode. Therefore, it is possible to dielectrically weld not only the vicinity of the stepped portion of the stepped portion of the stepped tube but also a range of a certain length in the axial direction from the stepped portion of the stepped tube. In FIG. 13, the dielectric welding range is emphasized by a thick line for illustration.

In the fifth embodiment, since it is possible to perform dielectric welding in a range of a certain length in the axial direction from the stepped portion of the stepped tube, there is an effect that the welding strength of the first tube and the second tube is increased. By increasing the number of electrodes as necessary, the dielectric welding range can be expanded in the axial direction of the tube.

The present invention relates to a high-frequency dielectric welding device for a stepped tube and a high-frequency dielectric welding method for a stepped tube, particularly a stepped portion in which a first tube and a second tube for medical use are overlapped, and a drip tube for a drip container. It can be applied to a high-frequency dielectric welding device for welding a stepped portion for mounting and a stepped portion where a tube and a joint overlap, and a high-frequency dielectric welding method for a stepped tube.

In addition to stepped tubes for medical use, stepped tubes for chemical experiments, stepped tubes for fluid control circuits such as pneumatic and hydraulic, and stepped tubes for various production machinery and equipment are used for high-frequency dielectric welding. Can be applied.

1 1st tube
2 2nd tube 3 1st electrode 4 Insulation plate 5 2nd electrode 6 Feeding part 7 Ground side surface plate 8 Arrow showing the direction in which the poles of plastic molecules are reversed 9 Welded part 10 Fitted to the 1st tube, etc. Tube P high frequency power supply

Claims (6)

Each is a high-frequency dielectric welding device made of a polymer resin material, in which one end of a small-diameter first tube is fitted into a large-diameter second tube and the overlapping ends of the first and second tubes are high-frequency dielectric welded. hand,
A first electrode having a pressing surface for applying a high frequency voltage by pressing the outer peripheral surface near one end of the first tube, and
A second electrode having a pressing surface that presses the outer peripheral surface of the overlapping end portion of the second tube and applies a high frequency voltage,
An insulating plate interposed between the first and second electrodes to electrically insulate the first and second electrodes, and is formed in a stepped manner when the first and second tubes are overlapped. An insulating plate having a side surface that abuts on the entire end surface of the second tube and is attached, and a pressing surface that presses an outer peripheral surface near one end of the first tube.
A high-frequency power source for applying a high-frequency voltage between the first electrode and the second electrode is provided.
When a high-frequency voltage is applied between the first electrode and the second electrode by the high-frequency power supply, the insulating plate blocks the high-frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube. A high frequency voltage is applied between the first electrode and the second electrode in the overlapping ends of the first tube and the second tube.
A region in which the first tube and the second tube are heated and melted due to the dielectric action that reverses the polarities of the molecules of the first tube and the second tube, and after the first tube and the second tube are melted together, they are cooled and solidified to weld each other. A high-frequency dielectric welding device characterized in that it forms. When a high-frequency voltage is applied between the first electrode and the second electrode by the high-frequency power supply, the insulating plate blocks the high-frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube. A high frequency voltage is applied between the first electrode and the second electrode in the radial direction in the overlapping ends of the first tube and the second tube between the first electrode and the second electrode. The high-frequency dielectric welding apparatus according to claim 1. A second insulating plate, a third electrode, a third insulating plate, and a fourth electrode are further superposed next to the second electrode in the axial direction of the second tube, and these second insulating plates are formed on the outer periphery of the second tube. The pressing surfaces of the plate, the third electrode, the third insulating plate, and the fourth electrode are pressed, and a high-frequency voltage is applied between the second electrode and the third electrode, and also between the third electrode and the fourth electrode. The high-frequency dielectric welding device for a stepped tube according to claim 1, wherein the contact surfaces of the first tube and the second tube are dielectrically welded. Each is made of a polymer resin material, and is a high-frequency dielectric welding method in which one end of a small-diameter first tube is fitted into a large-diameter second tube and the overlapping ends of the first and second tubes are high-frequency dielectric welded. hand,
A high-frequency voltage is applied by pressing the outer peripheral surface near one end of the first tube with the first electrode having a pressing surface to apply a high-frequency voltage and the outer peripheral surface of the overlapping end of the second tube. An insulating plate interposed between the second electrode having a pressing surface and the first and second electrodes to electrically insulate the first and second electrodes, and the first and second tubes are overlapped with each other. An insulating plate having a side surface that is attached in contact with the entire surface of the end surface of the second tube, which is formed in a stepped manner at the time, and a pressing surface that presses the outer peripheral surface near one end of the first tube, and the first. Using a high-frequency power supply for applying a high-frequency voltage between one electrode and the second electrode,
The pressing surfaces of the first electrode and the insulating plate are brought into contact with the outer circumference of the first tube.
The side surface of the insulating plate is brought into contact with the entire surface of the end surface of the second tube.
The pressing surface of the second electrode is brought into contact with the outer circumference of the second tube.
The high frequency power supply device is connected to the first electrode and the second electrode,
A state in which a high-frequency voltage is applied between the first electrode and the second electrode by the high-frequency power supply, and the high-frequency voltage applied between the first electrode and the second electrode with respect to the end face of the second tube is blocked by the insulating plate. ,
A high frequency voltage is applied between the first electrode and the second electrode in the overlapping ends of the first tube and the second tube between the first electrode and the second electrode.
The first tube and the second tube are heated and melted by the dielectric action that reverses the polarity of the molecule.
After the first tube and the second tube are fused with each other, they are cooled and solidified to weld each other.
A high-frequency dielectric welding method characterized by this. A high frequency voltage is applied between the first electrode and the second electrode in the radial direction in the overlapping ends of the first tube and the second tube between the first electrode and the second electrode.
The first tube and the second tube are heated and melted by the dielectric action that reverses the polarity of the molecule.
After the first tube and the second tube are fused with each other, they are cooled and solidified to weld each other.
The high-frequency dielectric welding method according to claim 4, wherein the method is characterized by the above. A second insulating plate, a third electrode, a third insulating plate, and a fourth electrode are further superposed next to the second electrode in the axial direction of the second tube, and these second insulating plates are formed on the outer periphery of the second tube. The pressing surfaces of the plate, the third electrode, the third insulating plate, and the fourth electrode are pressed, and a high-frequency voltage is applied between the second electrode and the third electrode, and also between the third electrode and the fourth electrode. The high-frequency dielectric welding method for a stepped tube according to claim 4, wherein the contact surfaces of the first tube and the second tube are dielectrically welded.

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