JPS6125187Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a high-frequency heating device such as a high-frequency induction heating device, a high-frequency induction welding device, or a high-frequency contact welding device, in which a conductor and a workpiece fixedly connected to a high-frequency power source are movable. The present invention relates to a water-cooled flexible connection conductor which is connected to a conductor fixedly connected to a head portion that heats a workpiece.

Generally, the above-mentioned high-frequency heating device includes a high-frequency power source fixed at a predetermined position, and a matching transformer, inductor, or contactor that is movable relative to the high-frequency power source for maintenance and adjustment of the position relative to the workpiece. It consists of a head section consisting of a
The voltage value is over 10 KV, the frequency is 10 KHz or more and 100 KHz,
It is constructed to be able to flow a high-frequency current with a current density of about 50 to 100 A/ ^mm2 , and can be bent in three directions: up and down, left and right, and front and back within a range of about 50 to 500 mm, following the movement of the head. In addition, it also requires cooling along with the head section to prevent high temperatures due to the skin effect and proximity effect caused by high frequency current.

Here, as a flexible connecting conductor that connects a fixed part such as a high frequency power supply part and a movable part such as a head part which is movably provided with respect to this fixed part, it has been conventionally shown in FIGS. 1 to 3. The following are known. That is, the flexible connecting conductor 1 shown in FIG. It is configured so that it can be connected to the movable part 4. However, this connecting conductor 1 is
Although it can be bent in any two directions (front and back), when the movable part moves in the remaining direction, it has the disadvantage that cracks occur due to twisting and are easily damaged. In order to secure the current capacity, the width (100 to 600 mm) must be increased accordingly, and it is also necessary to cool down the high temperature caused by the skin effect and proximity effect when high frequency current is applied. has no choice but to use air cooling, which has the problem of requiring a very large space.
By the way, in order to prevent the conductor parts of the fixed part 3 and the movable part 4 from being overheated due to the skin effect and proximity effect of high-frequency current, cooling water is generally supplied from the fixed part 3 side to cool them. However, in the case of the connecting conductor 1 made of laminated thin plates, a separate hose 5 for cooling water is required, which requires a large space and is uneconomical.

The connecting conductor 6 shown in FIG. 2 is composed of a metal tube formed by forming a copper or copper alloy pipe into a corrugated spiral shape, and has connections at both ends that can be fixedly connected to a fixed part 7 and a movable part 8. The flanges 9, 9 are integrally attached and are configured so that both current and cooling water can flow at the same time, but on the other hand, although it maintains a long life against movement in the expansion and contraction direction, it quickly resists twisting. In addition to cracks and damage, it is difficult to move large distances due to its lack of flexibility, and if you want to increase the movement distance, you must create bends in several places, and if bends are provided, the length of the bends must be determined. The problem is that the space required increases as the length increases, and as a result, the mechanism becomes complex and electrical loss increases. In addition, the connection conductor 6 has
The cooling water flowing through the inside turns into a vortex due to the wave-like irregularities, causing high-frequency vibrations, which may lead to premature failure due to fatigue failure and a water leakage accident. Furthermore, in order to flow a high-density current, it is necessary to increase the diameter of the tube, but there are problems such as the fact that it is extremely difficult to manufacture. Furthermore, in order to connect the end of the connecting conductor 6 and the connecting flange 9, as shown in FIG. However, when the connecting conductor 6 was bent, the terminal portion received the maximum stress and broke at that portion. For this purpose, some have attempted to reinforce the connecting conductor 6 by covering it with a metal wire braided tube 11 and brazing it integrally, but even though the metal wire braided tube 11 itself is air-cooled, Since the high frequency current flows to the outer periphery due to the proximity effect and the skin effect, there is a risk that the metal wire braided tube 11 itself may be burnt out.

The connecting conductor 12 shown in FIG. 3 has a plurality of stranded wire conductors 14 arranged around the outer periphery of a hard copper spiral 13 formed into a helical spring shape, and a tape 15 that restricts the movement of the stranded wire conductors 14 is wrapped around the outer periphery of the hard copper spiral 13. The outer periphery of is covered with a rubber sheath 16,
Inside the hard copper spiral 13 is a water channel 1 through which cooling water passes.
It is listed as 7. However, this connecting conductor 12 is 10K
If the frequency current is below Hz, the current density is
It can be used to achieve a current of about 10 to 20 A/ ^mm2 , but when the frequency increases to about 40 KHz, the two transmission paths installed parallel to each other should be placed close together to reduce inductance loss. However, as is well known, as a characteristic of high frequencies, the higher the frequency, the more pronounced the proximity effect and skin effect become, and the current path is shown by hatching in FIG.

In other words, the current density locally becomes extremely high, about 50 to 100 A/mm ² , and since the cooling water is designed to cool only the inside of the conductor 14, the conductor 14 is overheated, and the mechanical resistance against bending increases. There is a risk that the mechanical strength will decrease and there is a risk of burnout. In addition, in order to prevent the connecting conductor 12 from collapsing, the thickness of the conductor 14, rubber sheath 16, etc. is increased, but in this case, the weight of the connecting conductor 12 increases and the minimum allowable bending radius cannot be made smaller.

It is not as if there have not been ideas in the past in which the above-mentioned drawbacks have been eliminated. The present applicant has already disclosed the content in Patent Application No. 63592 of 1978. Here, the contents are as follows.

That is, FIG. 6 is a schematic front view of a high-frequency induction heating device 19, which is an example of a high-frequency heating device equipped with a connecting conductor 18 according to the present invention. The device includes a high-frequency power supply unit 20, such as a high-frequency oscillator, disposed at a predetermined position,
A head portion 2 is provided so as to be movable relative to the work 21 and for heating the work 21.
2 and the high frequency power supply unit 20 and the head unit 22
6 and 7, the high frequency power supply unit 20 is provided with two fixed transmission conductors 23, such as copper pipes, which can transmit cooling water from a pure water circulator (not shown) together with high frequency current and extend horizontally in parallel with each other.
In addition, two movable transmission conductors 26, such as copper pipes, are attached to the head section 22, which is composed of the matching transformer 24 and the inductor 25, in parallel and perpendicular to each other, similar to the fixed transmission conductor 23.
3, 26 are two connecting conductors 1 according to the present invention.
The head 22 is connected via the feeders 8 and 18. The head 22 is supported by a moving mechanism (not shown) so as to be movable in three directions, namely up and down, left and right, and front and rear, and the work 21 is automatically fed by a material feeding device (not shown).

As shown in FIGS. 8 and 9, each of the connection conductors 18 is connected to the flange portion 23 of the fixed transmission conductor 23.
a connecting fitting 27 that is detachably attached to a, a connecting fitting 28 that is detachably attached to the flange portion 26a of the moving transmission conductor 26, and both connecting fittings 27, 28.
A flexible hose 29 made of synthetic resin, such as a soft vinyl hose, whose ends are removably fitted into the connecting parts 27a and 28a, and a flexible hose 29 made of synthetic resin such as a soft vinyl hose, which is inserted through the inside of the hose 29 and whose ends are connected to the respective connecting fittings 27, It is composed of a cylindrical mesh-like braided conductor 30 fixedly or removably attached to the conductor 28, and a helical spring-like holder 31 made of a heat-resistant insulating hard synthetic resin such as a hard silicone rubber wire inserted into the conductor 30. Ru.
That is, one of the connecting fittings 27 consisting of a connecting part 27a and a flange part 27a is attached to the flange part 23a of the fixed transmission conductor 23, and the flange part 27b is removably attached to the flange part 23a by a plurality of fasteners 32 such as bolts. , both flanges 23
It is watertightly attached via a sealing member such as an O-ring interposed between a and 27b. A hole 33 for passing the cooling water and the conductor 30 is formed in the axial center of the connecting fitting 27, and one end 30a of the conductor 30 is attached to the flange portion 27b by soldering or the like. A flange recess 34 having a larger diameter than the hole 33 is provided for fixation.

Incidentally, the conductor end portion 23b on which the flange portion 23a of the fixed transmission conductor 23 is provided is formed in a ripple shape so that cooling water can be fed into the gap between the conductor 30 and the hole 33 as described later. There is.
On the other hand, one end of a flexible hose 29 is fitted into the connection 27a of the connection fitting 27, and is tightened watertightly via a suitable fastener 35 such as a hose band. Note that the outer peripheral surface of the connecting portion 27a is
The hose 29 is formed in an inclined step shape to improve watertightness with the hose 29 to be fitted, and the outer peripheral surface of the hose 29 is provided with a groove to prevent the hose 29 from being crushed even when bent with a small radius of curvature. A hard synthetic resin wire 36 such as a hard vinyl wire formed into the shape of a helical spring is integrally wound by welding or an adhesive as appropriate, except for the tightened portion by a hose band or the like.

By the way, the other end of the hose 29 is fitted into the connecting portion 28a of the other connecting fitting 28, as shown in FIG. 9, and is tightened watertightly by a plurality of fasteners 37. In this case as well, the outer circumferential surface of the connecting portion 28a of the connecting fitting 28 is formed in the shape of an inclined step similar to one of the connecting fittings 27, and the connecting fitting 28 is formed in the shape of an inclined step.
and a flange portion 28b integrally formed with the moving transmission conductor 26.
It can be attached to the movable transmission conductor 26 by being removably attached to the flange portion 26a with a plurality of fasteners 38, and the attachment is made watertight via a seal member 39. A hole 40 for passing the cooling water and the conductor 30 is formed in the axial center of the connecting fitting 28, and a hole 40 larger than the hole 40 is provided in the flange portion 28a for attaching the other end of the conductor 30. A flange recess 41 formed in the diameter is provided. The hole 40 is provided to have the same diameter as the hole 33 of the one connection fitting 27, and the conductor end portion 26b of the movable transmission conductor 26 is formed into a ruffled shape similarly to the fixed transmission conductor 23.

A conductor 30 is inserted into the hose 29 and is made by binding thin conductive wires such as copper wires or copper alloy wires and braiding them into a cylindrical mesh shape.
The outer periphery of is covered with a heat-resistant insulating spacer 42 made of, for example, glass fibers braided into a cylindrical mesh shape, or a flat tape braided into a mesh shape wrapped around the spacer 42, the outer diameter of which is as described above. The diameter of the holes 33 and 40 of each of the connecting fittings 27 and 28 is appropriately made smaller to ensure a gap. On the other hand, the conductor 30
A heat-resistant and insulating hard synthetic resin holder 31 shaped like a helical spring is inserted into the inner periphery of the holder 31 . As shown in FIGS. 8, 10, and 11, one end of the conductor 30 is divided into a plurality of parts and has a divided end part 30a bent outward perpendicular to the direction in which the conductor 30 extends. , each divided end 30a
is fixed to the bottom of the flange recess 34 of one of the connecting fittings 27 by brazing. In addition, the conductor 30
The other end is a split end portion 30b which is divided into a plurality of pieces and tied together as shown in FIGS. 9, 12 and 13.
One end of a connecting terminal 43 bent in an L-shape is fixed to each divided end portion 30b by compression, crimping, brazing, etc., and the other end of the connecting terminal 43 is attached to a cap screw. It is detachably connected to the bottom of the flange recess 41 of the connecting fitting 28 via a plurality of fasteners 44 such as the following.

Since the invention is constructed as described above, it is several times more flexible than conventional ones, and can be used even when the moving distance of the head section is large, or in other words, when a curved section with a small radius of curvature is created. It can be easily followed.

Furthermore, since the conductor is placed in cooling water and a current is passed through it, the conductor can be effectively cooled. That is, by inserting a heat-resistant insulating holder formed into the shape of a helical spring into the inner diameter of the braided conductor, the conductor is prevented from collapsing without impairing its flexibility, and water flow through the inner diameter is facilitated. By effectively cooling the inner diameter part of the conductor, and by providing a gap in the outer diameter part with respect to the hole diameter of the first and second connecting fittings or the inner diameter of the hose, and allowing water to flow through this part, This makes conductor cooling effective. On the other hand, the outer periphery of the conductor is covered with a spacer made of heat-resistant insulating fibers braided into a mesh, so even if the conductor is unevenly distributed with respect to the inner diameter of the hose, the conductor will not come into direct contact with the inner circumferential surface of the hose. Since the contact is made through the spacer through which the cooling water permeates, there is no risk of damage to the inner peripheral surface of the hose due to overheating of the conductor. Similarly, the outer diameter of the conductor contacts the inner circumferential surface of each of the connection fittings to form a bypass circuit, and there is no possibility that current will concentrate at the contact area, causing local overheating and damaging the conductor. ing. Furthermore, since the connecting fitting part of the fixed or moving transmission conductor is connected to the connecting conductor in a conical shape (expanded into a conical shape), the end of the conductor is bundled and divided into a plurality of pieces and connected to an L-shaped terminal. However, the heat generated by the contact resistance of the mounting part, which is removably attached to the connection fitting with a gap provided so that it does not come into contact with the inner peripheral surface of the connection fitting, can be effectively carried away by the cooling water, and the conductor end Cooling water can be sufficiently circulated through the gap between the outer circumference of the conductor and the inner circumference of the connecting fitting through the gap formed by bundling and dividing the section into a plurality of pieces.

However, the connecting conductor according to the above application is not without drawbacks. This is because pressure is applied to the cooling water by a pump, and in order to prevent water leakage due to this pressure, the outer circumferential surfaces of the connecting parts 27a and 28a of the connecting fittings 27 and 28, respectively, have sloped steps as described above. These connecting parts 2
With the hose 29 fitted to 7a and 28a, the hose 29 is attached to fasteners 35 and 37 such as hose bands.
However, if metal hose bands are used as the fasteners 35, 37, the hose bands themselves may be heated due to iron loss. There is a risk that the hose 29 may be melted or burned out, causing a water leakage accident. Traditionally, hose bands have generally been made of steel because of the need to ensure tightening strength, but the hose bands are heated due to the high-frequency alternating magnetic field generated by the flow of high-frequency current. That's why. In order to avoid this problem, it is conceivable to construct the hose band with non-magnetic stainless steel or non-ferrous phosphor bronze, which has a high tightening strength. However, even with this, there is a drawback that heating occurs due to induction at high frequencies of about 200 to 400 KHz. Therefore, copper wire, which is least susceptible to the effects of magnetic fields, is currently used as a hose band, but the leakage magnetic flux increases as the flexible distance and current density increase. The disadvantage is that it is not an exception because it increases in number. Copper wire has a weak tightening strength and is difficult to form into hose band fittings, so the method of tightening the hose is to wrap the copper wire around the hose and tie it. This method requires skill and has the disadvantage that uniform tightening force cannot be obtained.

The object of the invention is to provide a flexible connecting conductor with a hose band that is not heated by high-frequency current.

For this purpose, the present invention provides that the hose band for watertightly fastening the hose to the conductor fitting is made of a non-magnetic and electrically non-conducting material, such as linen or cotton.
It is constructed using any one of braided glass fibers, etc., and is characterized by a structure in which a rope or string made of the above-mentioned material is wrapped around the hose in at least one layer. In addition, in order to help tighten the hose so that it does not come off the conductor connection fitting during subsequent use, the rope or string should also be wrapped around the conductor connection fitting near the end of the hose in a positioned manner. However, this wrapped rope or string is characterized by a configuration in which it is connected to a rope or string wrapped around the hose.

The present invention will be explained below with reference to FIGS. 14 and 15.

As mentioned above, in the present invention, the hose band is made of a material that is non-magnetic and electrically non-conductive, but such materials generally have a significantly weaker tightening force than metal materials. Therefore, it is clear that the necessary tightening force cannot be ensured only by using the above-mentioned non-metallic material. In consideration of this point, the present invention aims to strengthen the tightening force using thermosetting resin.

To specifically explain the present invention, Fig. 14 and 1
As shown in FIG. 5, while applying tension to a string 45 made of hemp, cotton, braided glass fiber, etc., the string 45 is first wrapped one layer around the connecting part 27a of the connecting fitting 27 in order to tighten the hose 29 watertightly. After that, the string 46 for connecting is placed on the surface of the layer of several strings 45, and then the string 4
5 in the direction of the flange portion 27b.

In this example, several strings 46 are extended in the flange direction at four locations, and their tips are accommodated in the recess space formed by the small flange 27c and the flange 27b, for example, as shown in the figure. . After this, the string 45 is wound again as shown in the figure with a tensile force applied to the string 46. It should be noted here that when carrying out the above treatment, the strings 45 and 46 are pre-impregnated with thermosetting resin such as epoxy, silicone, phenol, etc.
Processing such as winding shall be carried out before the resin hardens, and after finishing the winding, the ends of the string 45 are appropriately treated and then thermosetting resin 47 is applied to the outer surface of the strings 45, 46 to the required thickness. , it must be thermally cured under appropriate conditions. If heat curing is carried out appropriately, the necessary resin strength can be obtained, and thus the necessary clamping force and connecting force can be obtained. Although FIGS. 14 and 15 only show the tightening of the hose 29 to the connecting fitting 27, the tightening of the hose 29 to the connecting fitting 28 is handled in exactly the same manner. Further, the end treatment of the string 46 is directly related to the strength of the connecting force, but if the engagement between the strings 45 and 46 is made appropriate, the necessary connecting force can be obtained.

As explained above, the present invention involves wrapping a hose fitted onto a connecting fitting with a string made of a non-magnetic and electrically non-conducting material with the aid of a thermosetting resin. Since it is designed to be tightened, it has the following effects.

(1) Since the hose band is made of a non-magnetic and electrically non-conducting material, there is no leakage magnetic flux even when the frequency of the heating current is several hundred KHz and when moving in any direction. Since the hose band itself is not heated, water leakage accidents due to heating of the hose band itself can be completely eliminated.

(2) If the material combination of the hose band and thermosetting resin and the number of wraps are appropriate, the necessary tightening force can be easily secured. Incidentally, when glass fiber and epoxy resin are combined, the tensile strength can be increased to a higher tightening force than when using copper wire.

(3) Since the hose band itself is non-magnetic and non-conductive, no high frequency voltage is induced in the hose band itself, so it is safe to touch.

(4) Tension applied to the string and wrapping around the hose can be easily done by machine without relying on human hands, so the work does not require special skill and the accuracy of wrapping and tightening can be maintained at a constant level. can be maintained even higher.

(5) Unlike rubber molds, resin can be cured at low temperatures, so hoses made of transparent soft vinyl chloride or the like can be used.

(6) Even if a strong tensile force is applied to the hose, the tethering string will prevent the hose from being easily pulled out of the connecting fitting.

[Brief explanation of the drawing]

1, 2, and 3 are respectively a perspective view and a cross-sectional explanatory view of a conventional flexible connecting conductor, FIG. 4 is a partial cross-sectional view of the connecting conductor shown in FIG. 2, and FIG. Fig. 3 is an explanatory diagram of the current path in the connecting conductor, Fig. 6 is a schematic front explanatory diagram of a high-frequency heating device equipped with a connecting conductor according to the invention filed by the present applicant, and Fig. 7 is a side explanatory diagram thereof. 8 is a cross-sectional explanatory diagram of a connection conductor according to the invention, with a part of one end broken away, FIG. 9 is a cross-sectional explanatory diagram of the other end, and FIG. FIG. 11 is a perspective view of one end of the conductor in the connection conductor, FIG. 12 is a view taken along line B-B in FIG. 9, and FIG. 13 is the other end of the conductor in the connection conductor. 14 and 15 are a partially broken and sectional explanatory view showing one end of an example of the connecting conductor according to the present invention, and a partially omitted and sectional explanatory view taken along line C-C. 27, 28... Connection fittings, 27a, 28a...
Connection part, 29...Hose, 30...Conductor, 31...
...Holder, 42...Spacer, 45, 46...
String, 47...Thermosetting resin.

Claims (1)

[Scope of utility model registration request] A connecting conductor that connects a fixed transmission conductor of a high frequency power supply unit fixed at a predetermined position in a high frequency heating device and a movable transmission body of a head unit that is movably provided with respect to the workpiece and for heating the workpiece, One end of a soft flexible hose made of synthetic resin is fitted into the connection part of the first connection fitting which can be freely connected to the fixed transmission conductor, and the other end of the hose can be connected to the movable transmission conductor. The conductor is fitted into the connecting part of the connecting fitting, and is inserted into the hose as a conductor formed by braiding a thin conductive wire into a cylindrical mesh shape having a diameter smaller than the hole diameter of the first and second connecting fittings. A conductor is covered with a spacer made of heat-resistant insulating fibers braided into a mesh, and a heat-resistant insulating holder shaped like a helical spring is inserted into the conductor, and a plurality of ends of the conductor are inserted. A flexible connecting conductor in a high frequency heating device configured to be divided into two parts and fixedly or removably connected to the flange recesses of the first and second connecting fittings is non-magnetic and electrically non-conductive. A string made of a certain material is impregnated with a thermosetting resin and fitted onto the connecting part of the connecting fitting while applying tension.The connecting part of the hose, the flange/small flange of the connecting fitting. The two strings involved in the wrapping are connected by at least the same type of string for connecting, and the outer surface is later coated with thermosetting resin to a required thickness. A flexible connecting conductor in a high frequency heating device characterized by a structure in which the conductor is overcoated and cured.