DE2207713A1 - High frequency welding machine - Google Patents

Description

Dipl.-Ing. Heinz Bcrdehle

Petenfonwalt

D-8 Mürchen 26. P.O. Box 4
Telephone 0811/29 23 55

Munich, the 1%. February 1972

My reference: P 1380
Applicant: USM Corporation

Flemington, New Jersey
Delivery address: Balch Street

Beverly, Mass. Ol 915 United States

High frequency welding machine.

The invention relates to a high-frequency welding machine for processing workpieces made of weldable material or of workpieces made of non-metallic and non-weldable layers, but with one that can be activated by heat Intermediate layer are provided with a pressing member and fastening means for workpieces that are arranged in a larger number and of which by a relative movement between the pressing member and the workpiece fastening means, each fastener is selectable and in one opposite to the pressing member The position is adjustable, with a high-frequency welding through the application of pressure and a high-frequency field on a work piece that is fastened and opposite the pressing member can be carried out and the strength of the high-frequency field can be set independently for each attached workpiece and

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the pressure that is used for every HF weld, can be selected according to the workpiece opposite the pressing member.

An HF welding machine from the The type described above was proposed in the description of patent application P 17 78 008. With this welding machine the variation of the H.F. field strength to be applied is caused by two selector switch sets, each selector switch set in each case is assigned to a mounting location. Each selector switch set includes 4 switching options, which can be set as required can be used to set the field strength that is applied to the workpiece is used on the workstation assigned to the switch set.

It is understandable that this arrangement only has a limited number of possibilities, namely four «for a differentiated Establishing the applicable field strength offers. Furthermore, this arrangement is relatively complex because it has a number of Selector switches required; in addition, it is complicated in the electrical wiring requirement.

Lately attempts have been made to reach an unlimited number to provide setting options for the field strength independently of one another on the two workstations. Sine such Arrangement is described in German patent application No. 20 27 561.0. This arrangement is true in the number of Einetellossible not limited, but it is relatively expensive and complicated to manufacture. It's the job of the present invention to eliminate the disadvantages outlined above. According to the invention this object is achieved solved that the high frequency field is generated in a known manner by an RF generator and the RF generator one the output determining capacitor with two capacitor plates, one of which is movable, and that the Position in which the movable capacitor plate is set

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can be set independently for each workpiece mounting location is and that control means are provided which move the movable capacitor plate so that they each given HP welding work process at a workpiece fastening location is set according to the workpiece opposite the dem.Preß member.

Within the scope of the invention, the control means can have adjustable disconnection elements, one of which is each workpiece fastening place is assigned, and a closing element, which is connected to the movable capacitor plate, included, that the switch-on member when a selected workpiece mounting location Opposite the pressing member with the disconnecting member, which is assigned to the workpiece fastening area is, comes into engagement and that the movable capacitor plate in its predetermined for this workpiece mounting place Location is moved.

The closing element can be controlled in a suitable manner in such a way that a cam with one of the folding elements is used comes into engagement. One welding machine can have 2 two Contain workpiece mounting positions which form two operator positions and between which the pressing member moves can. In such a machine the cam is appropriately attached for the movement of the pressing member while the switch-on element is connected to the workpiece fastening means. Such an arrangement can be constructed in such a way that that the cam comes into engagement with the switch-on member when the pressing member moves towards one of the operating positions and disengages when the pressing member is moved towards the other of said operator stations. at such an arrangement may include springs for rubbing the movable capacitor plate towards the other be provided, the cam in turn brings the switch-on member into engagement with one of the switch-off members against the action of the springs and the springs in turn push that

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Closing element in engagement with the other of the closing elements.

In the context of the invention, the control means can also contain hydraulic means, which have a piston and cylinder arrangement and are provided for moving the movable capacitor plate into a selected position which corresponds to that predetermined for the workpiece mounting location relative to the pressing member.

With such an arrangement, the movable capacitor plate can be pushed away from the other capacitor plate by springs; the piston and cylinder arrangement, on the other hand, causes the plate to move in the direction of the other plate against the influence of the feathers. The hydraulic means usually comprise valves, one of which is assigned to each factory gap attachment and each of these valves is reset when the assigned workpiece attachment to the Opposite pressing member and that adjustable pressure regulating valves are also provided, each of which associated with each of the other valves and the pressure exerted on the piston and cylinder corresponding to the predetermined pressure of the pressure regulating valve which the Workpiece attachment is assigned, is selected when the workpiece attachment is opposite to the pressing member.

With this optional arrangement, in a machine constructed in accordance with the invention, a rotatable table can support the workpiece mountings, one around a selected one Workpiece fastening to be arranged opposite the pressing member, is to be rotated further, and that also for the method of operation of the valves there is provided control means adapted to move with the rotatable table.

It is understandable that the HF generator is usually provided with a tunable output capacitor,

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which contains a movable and a fixed capacitor plate. The relative position of the panels is varied by approximately Output field strength according to the general requirements of the operation to be carried out and the type of operation to be carried out Workpiece? However, they usually allow Adjustment means no precise and rapid variation of the plate position. In contrast, it is in accordance with the invention by providing suitable control means, it can be achieved to switch the output field strength precisely and quickly and thus to determine the HF-PeId to be applied to the workpiece without giving rise to expensive and complicated ones To give orders as it used to be.

In order to explain the invention in more detail, two exemplary embodiments are described with reference to the accompanying drawings described. The first of them includes a two-station welding machine in which the press member between the two places is moved back and forth and is opposite a workpiece attachment on each place. The second Example includes a welding machine with three places a rotatable table which rotates a selected workpiece fixture into the one opposite the pressing member Location brings. It will be understood that these first and second machines are only used for description as examples of the invention and were not chosen as a limitation on them.

In the drawing shows:

1 shows a schematic representation of the first machine

with tax funds for varying the applicable high-frequency electric field strength,

2 shows a part of the first machine in an enlarged view, which contains a Bowden cable arrangement as part of the control means,

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Fig. 3 is a side view of the second machine, in which individual parts have been omitted, and in which a tunable output capacitor of the HF generator and control means are shown, the strength of the output being independent according to the location of the Turntable can be varied, which is just opposite the pressing member,

FIG. 4 is a fragmentary view, on an enlarged scale, of FIG parts shown in Fig. 3,

FIGS. 5a and 5b show a schematic representation of a pneumatic control circuit of the second machine.

The machine shown in Figs. 1 and 2 is a two jobs comprehensive welding and cutting machine, the at each place a workpiece fixture, which is fixed on a lower plate (not shown), and has a pressing member in the shape of the top plate 18 (shown as a dash-dotted rectangle), which is for a back and forth Movement between the two places' is mounted and which is then opposite a workpiece attachment on each place.

ν The machine also includes an RF generator that is generally used with 20 and a tunable output capacitor which comprises a fixed plate 22 and a further plate 24 "which is movable relative to the fixed plate" and on the fixed plate is moved by a spring 26} the movement of the plate 24 relative to the plate 22 does this Varying or "tuning" the output field strength of the generator. The Qenerator is conventionally by no shown copper cables connected to the upper and lower plate, which also serve as electrodes of the machine, so that when the machine is in use and from the pressing member a pressure is applied to one fixed in the workpiece fixture Workpiece is exerted «a high-frequency electric field,

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the strength of which is controlled by the capacitance of the capacitor in accordance with the relative position of the plates 22 and 24 to one another is formed between the plates and can thus cause HP machining on the workpiece mentioned.

The first machine also contains control means by means of which both the position into which the movable plate is to be moved and the strength of the high-frequency field to be used can be set independently for each of the workstations? the fixing for each workpiece fastening is carried out according to the particular operation that is to be carried out when the said fastening place is opposite the upper plate. The control means, which are also operative when the upper plate is brought into the position opposite the fastening, cause the automatic movement of the plate 24 to its predetermined position in the said fastening position and consist of a block 28 which is fastened on the machine frame. The block 28 is made up of two plates 32 which are fastened together by the separating block 34 ^. are rotatable about a central opening 36 to ücaafferif in & i.j ilatir- an engaging element in the form of a lever 38 "> ■. ■ '; dc-ϊΐ bolt 40 is attached, which is guided in corresponding slots 42, which in the Plates 32. On the left end side (Fig. 2) of the lever 38 a roller 44 is mounted and another roller 46 is mounted at the same distance from the bolt 40 to the right as to the roller 44. The control means comprise also two adjustable disconnection elements 48 and 50 which are arranged adjacent to the two rollers 44 and 46. These disconnection elements consist of screws which are screwed into the threads of the spacer 34. The adjustable disconnection elements limit the movement of the plate 24 in such a way that that it is movable between two positions, each of which is assigned to a workpiece mounting location.

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For determining the end position of the movement of the lever 38 and for determining the end position of the plate 24, each of the switch-off members 48, 50 has a button 52 which is on the front end is attached. A scale is also provided to easily determine the location of the buttons and so on to act on the rollers 44 and 46 by means of the holding surfaces 54 and 56 at the rear end of the holding members 48, 50. It is Obviously, by varying the holding surfaces 54 and 56, two end positions of the movement of the lever 38 are defined can be

The control switching means of the first machine also contain nor limiting means represented by a surface of the partition block 34 and with the adjustable support members 48 and 50 work together, as will be described later. The bolt 40 also forms the pivot point for a pulley 58 over which a Bowden cable 60 is guided. One end of this Bowden cable is in the rear partition block 34 while the other end thereof is fixed on the movable plate 24 of the capacitor. The bowden cable runs over another pulley 62 directly to the plate 24. The Bowden cable 60 is over the pulley 58 and held taut between the pulley 58 and the plate 24 by the spring, the spring 26 acting on the plate. This way, every back and forth movement of the pulley effected by the block 28 and used by the Bowden cable to vary the position of the plate relative to the plate 22, wherein varying the capacitance of the capacitor changes the output field strength of the generator. Definitely that way the end position of the movement of the lever 38 is the end position of the movement of the lever in which the holding surfaces 54 and 56 are adjusted will. The end position of the plate 24 and the capacitance of the capacitor can also be varied in this way. The tax means of the first machine also comprise a cam 64 which is intended to cooperate with the lever 36 to make it so to move between its end positions; this cam 64 can be fixed in the lower part of the upper plate. The lever 38- is provided with a protruding part 66 on which one

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rotatable roller 68 is attached, this bolt extends in the path of movement of cam 64 when the latter is * as described above, with the upper plate moved around some inequalities of movement of the lever accordingly the positions of the holding surfaces 54 and 56 is to be balanced

the cam 64 is resiliently attached, thus indicating the end of the movement of the lever.

In the operation of the first machine, when the upper plate is, as shown, on the left workstation, the lever 38 and with it the pulley 58 is moved out of its position shown in FIG It is understandable that in this movement the lever first rotates clockwise (Fig. 2) around the axis of the bolt 40 and at the same time the bolt moves in the slot 42 under the tension exerted by the spring 26 on the Bowden cable 60. The lever 38 rotates around the axis until the roller 44 comes into engagement with the surface of the separating block 34, whereupon a further rotary movement of the lever takes place on the axis of said roller 44. This rotary movement continues until the roller 46 comes into engagement with the holding surface 56. It is understood that takes place during di · rotational movement about the second axis / the bolt is forced 40 to move against the influence of eggs spring 26 along AESS slot 42 and thereby the lever and AEIA movable plate 24, as indicated by the retaining surface 56 is intended to be relocated and how it is appropriate to the work to be carried out on the workstation on the left. It will also be understood that when the top plate is moved towards the right work station of the first machine, the retraction of the stop then allows the lever 38 to return to its original position under the influence of the spring 26, as shown in the figure .

In the invention, the machines can srsten Li: & as control means and electrical counterpoint ,; is-sxei'Sö änats. \ ^ & äss mesons 64 included, for example, if s .-. oh aie ofcere iPlcfefcs "Jon » ieii

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Moving right to the left, could be on the right A limit switch is de-energized on the side and a limit switch is energized on the left-hand side; in the electric Control circuit could be a force magnet for moving the Lever 38 may be provided between its end positions. This force magnet can be activated by operating the limit switch that comes with each workstation to which the plate is attached , moved, connected, controlled

The second type of machine will now be explained with reference to FIGS. 3, 4, 5a and 5b. It comprises a frame 110, on which a base plate 120 and a top plate 128 are attached. A piston and cylinder assembly C4 is mounted on the top plate and in rotatable mountings For example, another plate 138 is connected to a generally rectangular pressing member 142 via spacers in the form of insulators 140. A lower plate 124, too generally rectangular, is mounted on the base plate 120 adjacent the pressing member 142. The lower plate 124 and the Press members 142 are connected by connecting means in the form of a conductive strip 154 and 152 to the RF generator, respectively 156 connected.

The second machine also includes workpiece fastening means in the form of a rotatable table 160 which is rotatably supported on a journal bearing 162 within the machine frame, and comprises a plurality of, e.g., three workpiece mounting locations. Each of these is in the form of a generally rectangular mounting pad 166 made of polished aluminum and elastically inserted in the bottom of the rotating table. A blanket 178 made of spongy rubber on one side covered with p.t.f.e, is with each mounting plate 166 connected. Each plate forms a place on the rotating table and the three plates, generally labeled X, Y and Z. denoted are arranged evenly from each other at an angle of 120 in the rotating table. The rotating table is from

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To turn his hand to get to lie on the mounting thereon courts opposite the pressing member to one. A split ring 200 is arranged on the machine frame above the journal bearing 162, on which a brake 202 is fastened, which at its lower end carries three pneumatic valves V51, V52 and V53 (FIG. 5b); each of these forms three valves a part of the control means of the second machine type - actuators for these valves are arranged along the radius of the rotatable table. Above the center of the rotatable table is a mounting plate 164 by which the rotatable table is held on the journal bearing 162. Also attached are still on the rotatable table at equal intervals of the circumference of the disk along 164 three mounting plates 204 arranged, each carrying control elements 206 (two of which are shown only in FIG _o 3) which are each associated with one of the valves V5i V52 and V53 .

The second machine is so constructed and arranged that when station X of the rotating table is opposite clem 142, valve V51 is actuated by its associated moving actuator 206 ", - :; i -), t € gesc'iii " _? the places Y and Z in the same relationships -, - -κ Ι ·.-κ. '

■ ^ λ 1

V52 stand and V53 and each actuated by their AUJ supply members are _e The RF generator 156 includes ei? I? N tunable output capacitor which is generally designated by the 210th The condenser includes a plate 212 which is rotatably mounted and movable relative to the wall 214 of the resonance chamber of the generator (the latter forms the other plate of the condenser).

The control means also comprise means for changing the position of the plate 212 relative to the wall 214, which means comprise a piston and cylinder assembly C5 of a so-called rotary piston system, which is mounted on a frame 216 on which the Machine frame and the generator are attached, attached is. An upwardly directed piston rod 218 of this arrangement has at its lower end a bore 220 into which the lower

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End of a MeQstabes 222 fitted and through which it is in a U-shaped bracket 224 is attached by one on the Frame 216 mounted on the plate is held.

Towards the lower end, the measuring stick is provided with two split collars 228, between which slidable a U-shaped block 230 is inserted, between the legs of which the piston rod moves. The U-shaped block 230 has two pins 2.32 (one of which is shown in FIG. 3), one of which protrudes slightly from the block on each side; these pegs in turn engage in holes of a fork-shaped end piece on the arm 234 of an articulated lever, which is rotatably mounted on the plate 226. The other arm 236 of the articulated lever is also fork-shaped and carries a bolt 238 around which a further lever 240 is rotatably attached. The other end of the lever is rotatably mounted in the capacitor plate 212. The rotational movement of the plate is adjustable limited by two adjustable limiting screws 242 and 244 mounted on part of the frame of the generator. The piston and cylinder assembly C5 counteracts the influence of the spring 246, which in turn is between the upper sleeve and the surface of the bracket 224 is inserted so that the plate 212 is held away from the wall 214 by the spring when the arrangement C5 is not in operation. In order to set up the control means, the piston rod 222 is at its highest position adjustable with two adjusting screws 248 and 250. The adjustment screws are threaded on the top end of the provided piston rod arranged in such a way that each adjoins an arm of the bracket 224, depending on whether the arrangement C5 works or not; this arrangement is preferably made in order to measure the position of the limit screws 242 and 244.

In the operation of the second machine, the air pressure applied to the assembly C5 is corresponding to the Adjustment of the valves V51, V52 and V53 is controlled, namely depending on which of the valves is open the pressure itself through one of the three adjustable pressure regulators

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flow valves RV51, RV52 and RV53, one of which each is one associated with the aforementioned valves. It will be understood that by varying the amount of time applied to array C5 applied pressure is also varied, the pressure exerted by the assembly against the influence of the spring 246 is varied and thus the amount of movement of the plate 212 is determined, as it can be brought about by the articulated lever 234, 236. To this In this way, a variation in the output lever strength of the generator is achieved.

When the second machine is in use and an operation has just been completed, e.g. on the workpiece mounting station Z of the rotating table and the operator has prepared the next workpiece mounting location, e.g. location X, so she continues to turn the table by hand. The rotating table is locked (by the action of the microswitch MSl and the excitation of the magnet SVl, which in turn release the piston and cylinder arrangement) when the workpiece mounting area X is opposite to the pressing member 142, the valve V51 is actuated by the actuating member 206, and is thereby that valve V61 is switched so that the air with a Pressure, as indicated by the pressure regulating valve RV51, flows into the piston and cylinder assembly C5 to counteract the Influence of the spring 246 and to determine the position of the plate 212 and with it the output field strength of the generator

At the same time, the operation of the arrangement C1 does this Activate the microswitch MS2, which excites the magnet SV2, which on the other hand »via the regulating valve RV2 and the quick-release valve EV2 causes the piston and cylinder arrangement C2 and C3 to control the monitoring elements (not shown) lowers, whereupon the valves V2 and V3 are mechanically activated by the monitoring elements, and the pressure switch Getting PS4 into action. The prints cha it- M * 3? £ 4 foe » the excitation of the valves SV41 and SV42 and SV43 * acts with actuation the valve V51 through its actuator 3C6

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the pressurized air can escape through the valve SV41 to operate the valve V41, so that the pressurized standing air, as the pressure is determined by the regulating valve RV 41, through the quick release valve EV4 to the piston and cylinder assembly C4 can flow, which in turn causes the pressing member 142 to be lowered and with the up the mounting plate 166 inserted workpiece, which form the space X, come into press contact. The pressure on this The way it is applied to the workpiece is regulated by the regulating valve RV41. In the case of editing on the Positions Y and Z each allow the valves V52 and V53 Air passage through the magnets SV42 and SV43 to switch the valves V42 and V43, whereupon the air, as well as through the Pressure regulating valve RV42 and RV43 set, to which piston-cylinder comes to order C4.

The operation of the pressure switch PS 4 also causes the excitation of an electrical timing device Tl (which is not shown), which is enabled after a certain time H.F «generator to be switched on and thus the formation of a high-frequency electric field between the lower plate 124

Vl? and to effect the Pressgliea. The measuring of the certain Time by the time device Tl also causes the de-excitation of the valve SVl, so that the air through the piston and The cylinder arrangement Cl escapes in order to release the rotatable table for the next rotary movement.

The duration of the time during which the H.F. field is developed, is always controlled by an adjustable electrical time bed T21. From the counting of this time-keeper from the H.F. field is switched off, but the pressure continues for a certain time, in which the workpiece cools down and and can consolidate. This time is controlled by a further electrically adjustable timer T31. Waiting for this time then causes de-excitation of the valve SV43, so that the pressure member 142 in its output

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situation can return. The valve SV2 is also de-energized when the timer T31. Has measured the specific time, so that the monitoring elements also return to their original position can. When the workpiece mounting positions Y and Z are used, the electrical timing devices take over, respectively T22 and T23 the dimensions of the times during which the H.F. field is formed and those which can also be set Timing devices T32 and T33 determine the duration of the subsequent cooling time. The latter is also measured the de-energization of the valves SV41, SV42, SV43 and 8V2.

The second type of machine just described is now ready to turn the rotating table again and the next »latz to bring into a position opposite to the pressing member.

Even if the second type of machine in this exemplary embodiment had a table with three places * it is understandable that other machines in accordance with the invention of the operation of the second type of machine can also have four or more places second machine type also only have two places} in this case, however, the rotatable table does not need to make a full turn, but it can e.g. change a segment of a circle of a little more than 240 °.

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Claims (1)

Expectations 1. High-frequency welding machine for processing workpieces made of weldable material or workpieces made of non-metallic and non-weldable layers but with an intermediate layer that can be activated by heat, with a pressing member and fastening means for workpieces that are arranged in a large number and of which each fastening means can be selected by a relative movement between the pressing member and the workpiece fastening means and can be set in a position opposite the pressing member, with the use of pressure and a high-frequency field being able to perform high-frequency welding on a workpiece which is fastened and opposite to the pressing member, and thereby the strength of the high-frequency field can be set independently for each attached workpiece and the pressure that is used for each HF weld can be selected according to the workpiece opposite the pressing member, characterized in that the Hoc hfrequency field is generated in a known manner by an HF generator and the HF generator has a capacitor determining the output with two capacitor plates, one of which is movable, and that the position in which the movable capacitor plate is set is independent for each workpiece mounting location is adjustable and that control means are provided which move the movable capacitor plate so that it is adjusted for each given HF welding operation at a workpiece mounting location corresponding to the workpiece opposite the pressing member. 2. High-frequency welding machine according to claim 1, characterized in that the control means adjustable disconnection means (48, 50), one of which is assigned to each workpiece mounting location, and a switch-on element (38) which is connected to the movable capacitor plate (24) contain that the switch-on element (38) when a selected workpiece 209836/0878 fastening place opposite the pressing member (18) with the disconnecting member (48.50), which is assigned to the workpiece mounting location is, comes into engagement and that the movable capacitor plate (24) in its for this workpiece mounting place predetermined position is moved. 3. High frequency welding machine according to claim 2 _t characterized in that the normally open (38) by a cam (64) with one of the switching elements (48,5C | engages.. 4. High-frequency welding machine according to claim 3, characterized in that that the cam (64) is fastened on the pressing member (18) and the switch-on member (38) is fastened to the workpiece fastening point assigned. 5. High-frequency welding machine according to claim 4 with two workpiece attachment places, which form two operator stations and between which the pressing member can be moved, characterized in that, that the cam (64) comes into engagement with the switch-on member (38) when the pressing member (18) is moved towards one of the operating positions, and disengages when that Pressing member (18) is moved towards the other operator station * 6. High-frequency welding machine according to one of claims 3, 4 or 5, in which springs for actuating the movable capacitor plate provided in the direction of the fixed capacitor plate are, characterized in that the cam (64) the switch-on member (38) in engagement with one of the switch-off members (48.50) brings against the action of the springs (26) and that the springs (26) the switching element (38) in engagement with the bring other of the mentioned disconnection elements (48,50) " 7. High-frequency welding machine according to claim 1, characterized in that that the control means consist of hydraulically operating means, which include a piston and cylinder arrangement (C5) and are provided for moving the movable capacitor plate (212) into a selected position that corresponds to the Workpiece mounting place in relation to the pressing member predetermined is equivalent to. 209836/0878 θ. High-frequency welding machine according to Claim 7, characterized in that the movable capacitor plate (212) by Springs (246) is pushed away from the other capacitor plate (214) and the piston and cylinder assembly against it causes the plate movement in the direction of the other plate against the influence of the springs 9. High-frequency welding machine according to claim 8, characterized in that valves (V51, V52, V53) are provided, of which is associated with each workpiece fixture and each of these valves is reset when the associated Workpiece fastening is opposite to the pressing member and that adjustable, pressure-regulating valves are also provided, each of which is associated with each of the other valves and the pressure exerted on the piston and cylinder according to the predetermined pressure of the Pressure regulating valve associated with the workpiece attachment is selected when the workpiece attachment opposite to the pressing member. 10.High frequency welding machine according to claim 9, with a rotatable table which carries the workpiece fastenings and which is to be rotated around a selected workpiece fastening opposite the pressing member, characterized in that control means are provided for the operation of the valves, which are for movement with the rotatable table are provided. ^x 209836/0878