JPS6140509Y2 - - Google Patents

Description

[Detailed description of the invention] This invention clamps a sheet-shaped workpiece between the processing surface of a processing horn fixed to an ultrasonic vibrator and a presser roller, and applies ultrasonic vibration to the processing horn. In an ultrasonic processing machine that welds workpieces by feeding the workpieces while moving the workpieces, the device relates to a no-load oscillation prevention device that ensures safety when the workpieces are driven without being pinched, that is, with no load. A control signal generation circuit is connected via an elastic contact to a bearing that is rotatably supported and electrically connected to the bearing, thereby making effective use of existing components and producing ultrasonic waves that operate reliably. This invention relates to a no-load oscillation prevention device for processing machines.

Conventionally, when this type of ultrasonic processing machine is operated in a normal state in which a workpiece is held between the processing surface of the processing horn and a presser roller, the ultrasonic vibrations applied to the processing horn are too,
The ultrasonic vibrations are spent welding the workpiece, but when the workpiece is not clamped and is driven without load, the ultrasonic vibrations are directly transmitted to the presser roller, so the presser roller or processing horn is This has caused problems such as damaging the machined surface, shortening the tool life, and causing noise.

This invention was devised to solve the above-mentioned problems and achieve further effects, and one embodiment thereof will be described in detail below.

In the figure, reference numeral 1 denotes a workbench that constitutes a part of the machine frame, and fixes the bed 2. An arm 3 is integrally formed in the upper part of the bed 2, and a motor 4 is fixed to the lower part. A pulley 5 is connected to the motor 4 and is configured to rotate a main shaft 7 supported within the arm 3 via a belt 6. A pulley 8 is fixed to the left end of the main shaft 7 in FIG.

A presser bar 12 is provided in the head portion 10 of the arm 3.
is supported slidably in the vertical direction, and at the lower end of the presser bar 12 are two support plates 13a and 13 made of an insulating material, as shown in FIG.
A supporting member 13 is attached to the support member 13, which is fixedly integrated with the connecting plate 13c, which is also made of an insulating material, in a so-called inverted U-shape. Further, the support plates 13a and 13b include an inner ring 14a,
Outer ring 14b and sphere 14 interposed between the two wheels
Each of the bearings 14 made of a conductive material is fixed in an embedded state, and these bearings 14, 14 rotatably support the presser roller 11, which is also made of a conductive material, and at the same time, the presser roller 11 is also made of a conductive material. Bearings 14, 14 are electrically connected to the roller 11. Reference numeral 15 denotes a hole bored in one support plate 13a to a depth that communicates with the outer ring 14b of the bearing 14.A coil spring 16 as an elastic contactor is first housed in this hole, and the tip of the coil spring 16 is inserted into the bearing 14. Then, the screw 17 is inserted into the hole 15 to press the coil spring 16 and at the same time to electrically contact the coil spring 16, and the head of the folding screw 17 and the support A terminal 18 is connected between the end face of the member 13b and the end face of the member 13b.
is held in between and connected via a lead wire 19 to an appropriate control signal generation circuit (not shown). This control signal generation circuit always maintains the potential of the terminal 18 at a potential higher than the ground potential, and in this state, the power supply circuit for supplying high-frequency current to the ultrasonic transducer 27, which will be described later, remains in an operating state. be done.

A V-groove is integrally formed on one side of the presser roller 11, and an annular elastic member 20 having a circular cross section and having an outer diameter several hundred microns larger than the presser roller 11 is fitted into the V-groove. On the other hand, the presser bar 12
A stopper 21 is fixed to an intermediate portion of the arm 3, and a presser spring 22 is interposed between the stopper 21 and the arm 3 to constantly press the presser bar 12 downward.
A cam portion of a presser foot lifting lever 23 is in contact with the lower surface of the stopper 21, and when this lever 23 is raised upward as shown in FIG. 1, the presser foot bar 12 is latched at the upper release position. In this state, the belt 9 placed between the pulley 8 and the presser roller 11 is loose. When the presser foot lifting lever 23 is lowered, the presser bar 12 is pressed downward by the presser spring 22, and the presser roller 11 is pressed against a processing horn 28, which will be described later, via the support member 13, as shown in FIG. .

A frame 1a hanging downward is fixed to the lower surface of the bed 2, as shown in FIG. A pair of L-shaped supports 2 are provided on the sides of this frame 1a.
4 is fixed. A casing 26 of a vibrator assembly 25 is rotatably supported by the pair of supports 24 via bearings (not shown) about a central axis in the vertical direction. An ultrasonic transducer 27 is integrally fixed within this casing 26,
The vibrator 27 is ultrasonically vibrated in the vertical direction when high frequency power is supplied.

A machining horn 28 having a cylindrical upper portion is integrally fixed to the ultrasonic vibrator 27, and the upper end surface of the machining horn 28 is disposed perpendicular to the vibration direction of the horn 28. A flat annular processed surface 29 is formed. This processed surface 29
is arranged through a circular hole 30 formed in the workbench 1 and the bed 2 so as to be on the same level as the top surface of the bed 2, and is located at a position radially away from the center of rotation of the presser roller 11 and the processing surface 29. are arranged to face each other. Further, as shown in FIG. 2, at the contact portion between the presser roller 11 and the processing surface 29, the rotational directions of the presser roller 11 and the processing surface 29 are the same, and the workpiece 39, which will be described later, is linearly moved forward. It is configured so that it can be sent.

At the bottom of the vibrator assembly 25, a pair of current collecting rings 32 and 33 are connected to the casing 2 with an insulator 31 in between.
It is fixed so that it rotates together with 6. These current collecting rings 32, 33 have spring contacts 34, 35 fixed at one end to the frame 1a.
are in contact with each other, one of the contacts 34 and 35 is connected to the positive pole of a high frequency oscillator (not shown), and the other is connected to the negative pole. Further, each of the current collecting rings 32 and 33 is connected to each pole of the ultrasonic vibrator 27.

Here, the frame 1a is suitably grounded, and therefore the support 24 is connected to the frame 1a.
A machining horn 28 electrically connected to the
is also held at ground potential.

A pulley 36 is integrally fixed to the lower end of the vibrator assembly 25. Further, a motor 37 is fixed to the lower part of the frame 1a, and the pulley 36 is connected to the motor 37 via a belt 38.

When welding the workpieces 39 made of sheet-like thermoplastic resin materials in such a configuration, first, as shown in FIG.
0 in the upper position. Then, two or more workpieces 39 stacked one on top of the other are placed on the bed 2 between the presser roller 11 and the machining horn 28, the machining start position is set, and the presser foot lifting lever 23 is lowered to release the elastic member 20. is deformed by its own elasticity until the presser roller 11 comes into contact with the workpiece 39, and the workpiece 39 is held between the presser roller 11, the elastic member 20, and the machining horn 28. When a processing start switch (not shown) is turned on in this state, a high frequency oscillator (not shown) sends an ultrasonic wave to the ultrasonic vibrator 27 via the contacts 34, 35 and the current collecting rings 32, 33.
High frequency power is supplied to the machining horn 28 to apply vertical ultrasonic vibrations, and the overlapping workpieces 39 are welded by the vibrations. At this time, the motors 4 and 37 are also energized, and the presser roller 11 and the machining horn 28 are rotated in the same direction at approximately the same speed in the machining section, and the workpiece 39
are successively fed and welded continuously. At this time, since the elastic member 20 is in pressure contact with the workpiece 39, it acts to feed the workpiece 39 in the tangential direction of the presser roller 11, and the straightness of the workpiece 39 is extremely good.

Now, in contrast to the above, if it is attempted to drive the workpiece 39 without sandwiching it between the presser roller 11 and the machining horn 28, the presser roller 11 can be directly used for machining without intervening the workpiece 39. Since it comes into contact with the machined surface 29 of the horn 28, the coil spring 16 as an elastic contact is electrically connected to the bearing 1.
4 to the machining horn 28 via the presser roller 11, and is connected to the ground potential. For example, a small current as a control signal flows to the ground point of the commercial horn 28, and based on this, the supply of high frequency power from the high frequency oscillator to the ultrasonic vibrator 27 is stopped. Therefore, no ultrasonic vibration is applied from the machining horn 28.

Note that when the high-frequency power supply from the high-frequency oscillator to the ultrasonic transducer 27 is stopped as described above, the motor 4 and the motor 37 are simultaneously operated, in other words, the presser roller 11 and the machining horn 2 are stopped.
8 may also be stopped. Further, regarding the presser roller 11 and the machining horn 28, only one of them may be driven to rotate by a motor, and the other may be rotated in conjunction with the motor. Furthermore, the elastic contactor may also be made of other than the coil spring 16, such as a plate spring.

As detailed above, the no-load oscillation prevention device for an ultrasonic processing machine according to this invention is such that when the presser roller comes into contact with the machining horn, the bearing that rotatably supports the presser roller receives an electric charge. When the elastic contact brought into contact with the processing horn reaches the same ground potential as the processing horn, the supply of high-frequency power to the ultrasonic vibrator is stopped by a control signal from the control signal generation circuit connected to the elastic contact. This is a feature of the present invention, which prevents damage to the press roller or the machining horn when the workpiece is driven without being sandwiched between the press roller and the machining horn. Moreover, by focusing on the fact that the bearing that rotatably supports the presser roller is electrically connected to the presser roller, we cleverly modified existing components such as the bearing, the presser roller, and the machining horn. Since the bearing is used for the above-mentioned purpose, the complexity of the structure can be sufficiently suppressed.Furthermore, since the above-mentioned bearing is in contact with an elastic contact and the control signal generation circuit is connected to this elastic contact, it can be easily resistant to vibrations, etc. It also has good followability and can be operated reliably.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of the main part showing an embodiment of this invention, and FIG. 2 is a partially enlarged sectional view. In the figure, 11 is a presser roller, 13 is a support member, 1
4 is a bearing, 16 is a coil spring (elastic contactor), 25 is a transducer assembly, 27 is an ultrasonic transducer,
28 is a processing horn, and 29 is a processing surface.

Claims (1)

[Scope of utility model registration request] A vibrator that vibrates ultrasonically when high-frequency power is supplied from a high-frequency generator; a processing horn that is fixed to the vibrator and held at ground potential;
A presser roller made of a conductive material that cooperates with the machining surface of the processing horn to clamp the sheet-like workpiece, and is electrically connected to the presser roller and rotatably supports the presser roller. a support member formed of an insulating material that fixes the bearing and supports the presser roller so as to be able to move toward and away from the processing surface; an elastic contact that electrically contacts the bearing; and a control signal generating circuit connected to the elastic contact, and when the presser roller contacts the processing horn and the elastic contact reaches the ground potential, the control signal from the control signal generating circuit generates the vibration. A no-load oscillation prevention device for an ultrasonic processing machine, characterized in that the supply of high-frequency power to the child is stopped.