DE3121229A1 - Device for welding the coupling wires in an electromechanical filter - Google Patents

Abstract

A device for welding the coupling wires (6, 7, 11) in an electromechanical filter is proposed in which two electrodes (17, 37) each are pressed against one another with interposition of the coupling wires (6, 7, 11) and vibrating elements (2) (resonators) in accordance with the spot welding method. The lower electrode consists of a common element (17) for all resonators and the upper electrode consists of electrodes (37) which can be separately activated for each welding spot and which are pressed on by means of a spring bow (31). In addition, holding and clamping devices for the resonators (2, 5, 10) are provided in a base frame, which devices, for actuating such pincer-shaped holding elements (24a, 24b) have an actuating shaft (13) with levers (15). A frame (Figures 7, 8, 9) provides for the presorting of the resonators. The welding process is electronically controlled. <IMAGE>

Description

Device for welding the coupling wires in a

electromechanical filter The invention relates to an apparatus for welding the coupling wires in an electromechanical filter, in which using the spot welding method, two electrodes with the coupling wires in between and vibrating elements (resonators) are pressed against each other.

Up until now it was common practice to use the coupling wires in electromechanical filters to be welded with the individual resonators more or less by hand in individual steps. Such a filter is shown in principle in FIG. 1 in perspective.

Figure 2 shows this filter in a cross section and below in a plan view, not all resonators shown in the plan view are.

The resonator elements 5 are at certain points via coupling wires connected with each other. Usually is at the bottom of the resonator elements a common coupling wire 11 is provided, which extends up to the on the outside located electromechanical transducers 10 extends. The entire row of resonator elements is indicated by 2 in FIG. The resonator elements are mechanically over Wire legs 4 held in a socket 1. The electrical connections 3 of the Filters lead through the receptacle 1 to the electromechanical transducers 10. Furthermore, a part of each of the resonator elements 5 is via a so-called over-coupler in the form of a wire 6, 7 with one another tied together. The upper coupling wire (2 coupler 6, 7) is not to be welded to every resonator element.

The resonator elements have different dimensions in their longitudinal direction and also in their execution, which ultimately defines the characteristics of the electromechanical Determine filters. The mutual distance between the resonator elements is precisely defined and is maintained over the long term by the welding points with the coupling wires.

The invention is based on the object of specifying a device due to the spot welding of the individual resonator elements with the coupling wires can be carried out automatically in just a few work steps not only take care of the adjustment of the position of the resonator elements with one another but also be suitable for different designs of such filters.

This object is achieved by a device as described in the claim 1 is outlined.

Further improvements to this device can be found in the subclaims.

FIG. 3 shows the lower part of the welding device with brackets for the coupling elements in the top view and in the side view.

FIGS. 4 and 5 show sections in those indicated in FIG Levels.

FIG. 6 shows a view from one side of the device.

FIG. 7 shows a plan view of a holding device for the Resonator elements.

Figures 8 and 9 show sections of this holding device in specified levels.

Figure 10 shows a single top electrode.

FIG. 11 shows a package of top electrodes.

FIG. 12 shows a spacer element of the holding device according to FIG 3.

FIG. 13 shows a side view in the axial direction of the resonator elements.

Figures 14 to 16 show different types of top electrodes.

FIG. 17 shows an individual element from FIG. 3.

The device basically consists of two electrode holders. The lower electrode is a common electrode in the form of a rod 17, which is shown in FIG a clamping device 18 is held. The whole thing is on a base plate 12 combined with a pressure shaft 13, mounted in brackets 14, which is used to the pincer-shaped gripper elements to be explained later for the individual resonators to operate. The common electrode 17 is replaceable and extends below of the lower bobbin wire that rests on this electrode. The lever 15 is used to operate this shaft. The shaft is still with electrical encoder elements 49, whose connection unit 16 is also on the base plate, connected to the for the electrical Niche control in the individual phases of the welding process are relevant. The distance between the individual resonator elements in the longitudinal direction of the filter comb 2 (FIG. 1), insulating pins 19 and 20 are provided. If there are greater distances between individual resonator elements, the material is there made of ceramic; because the distance between the electromechanical transducers and the closest resonator elements is very small, there is always a thin one resilient insulating element 20 is arranged. At the end of the row of resonators are spring claws 21 (see individual illustration in FIG. 17) is provided, which is used to press the two outermost last resonator elements against the first rigid ceramic pin 19, 20 after inserting the Re sonator elements ensure.

The individual resonator elements are already in place before the welding process provided with holding legs. With these holding legs 4 they grip into a receiving device in the form of a plastic frame (magazine) according to FIGS. 7 to 9. The plastic frame forms the coarse centering and holder for the resonator elements, for which purpose he means a bore 22 engages a pin 23 on the lower plate 12 and after Glide past the spring claws 21, which later become the outermost resonator elements press down, click into place (Fig. 3, 17). The individual electrodes are placed before the welding process held for position determination by means of resilient pliers 24 in its axial direction.

The spring pliers can be seen better from FIG. You insist of two levers 24a and 24b which are connected to one another via a joint 25. The lever elements are mounted on common shafts 26 for all.

Bolts 27 prestressed by means of springs 28 press on one lever arm 24b, so that normally the pliers is closed and the drawn Resonator element 5 holds. The shaft 13 with actuating lever 15 for actuating this Lever arm is flattened at one point, making them similar to an eccentric at Pivoting movement of the lever 15 opens the pliers for receiving the resonator elements 5. The aforementioned electrical transmitter elements 49 actuated.

Serve longitudinally to accommodate the coupling wires and to determine their position the lower electrode distributed wire holders 29. These wire holders are shown in detail in Figure 12 and basically have a U-shape. The distance A of the two legs of the wire holder is designed so that the lower one is thick Coupling rotates 11 can be inserted. The later after the first welding process of the resonator elements The upper coupling wire 6, 7 to be placed with the lower coupling wire is thinner and therefore thinner it is also positioned correctly, is on one leg of this leaflet-shaped Wire holders a small magnetic element 30 attached. The section of the U is not straight but so bent that after the upper coupling wire 6 is in place one leg (because of magnetic pull) the axes of the two coupling wires lie vertically on top of each other. The offset is shown exaggerated.

The upper part of the welding device consists of a package of Single electrodes of double E-shape according to.

Figure 10. The entire package of these mutually isolated but rigid held individual electrodes is shown in Figure 11 viewed from the front. In the In the middle of the two E-shaped spring elements 31 are the outer legs with an electrode holder 32 integrally connected. The electrode holder is therefore resiliently mounted. Means of the clamping device 33, 34, 46, 47 are the individual electrodes on their middle legs 35 against each other kept isolated. In the middle of one E-shaped An electrode 36 is provided in each case for the electrical connection of the spring element. the Spring elements are preferably made of copper beryllium. The electrode holder 32 has a bore for receiving the upper welding electrode 37, which by means of a Clamping screw 38 can be held. To have different set pressures when welding An additional spring (leaf spring) can also be achieved for individual welding points 40 provided. This can be done individually by means of adjusting screws 41 and 42 can be adjusted, that is, the additional pressure can be ideal here again for the individual Weld points can be set. The nut part 45 for the adjusting screw 42 can by one, not shown in detail, for the entire electrode package common device can be pivoted upwards, so that per weld optionally two welding pressures can be selected. The spring 40 is over a plastic cap 47 isolated from the electrode holder 37.

The individual electrodes 37 have different ones towards the welding point Shapes as shown in Figures 14-16. This is therefore necessary because the individual resonators have different shapes and there, like the figure 13 shows that the upper coupling wire 6, 7 is only welded to two resonator elements should be and therefore to avoid contact with those in between Resonators must be slightly bent. As a result, the associated electrodes are for these weld points, as can be seen in FIG Weld to achieve this actuation automatically. The electrode according to FIG. 15 has a groove 38 so that it overlaps the upper coupling wire.

The electrode according to FIG. 14 has a bevel 39 in order to avoid that in the electromechanical transducers 10, the eccentrically seated piezoelectric Excitation element 44 is damaged.

The entire facility is controlled by rectifiers fitted with thyristors controlled in such a way that the individual welds are performed one after the other at different times can be carried out. The welding of the lower coupling wire can thereby take place in one operation; Then the device is opened again so that the upper coupling wire can be inserted and after closing the upper coupling wire to be welded to the resonators.

With the actuating device (shaft 13) for the tong-shaped gripper is an L-shaped plastic element 43 between the center of the device both upper coupling wires indented as a side stop for both. This Pressure element 43 can be seen in FIG.

17 Figures 6 claims Blank page

Claims (6)

claims oil device for welding the coupling wires an electromechanical filter with two electrodes using the spot welding method with the interposition of the coupling wires and vibrating elements (resonators) against each other be pressed, that is, that one electrode (17) under the lower coupling wire (11) that connects all resonators and forms the common electrode for the individual welding points and the Upper electrode made of a single spring element for each welding point consists, which has the shape of a double E (Fig. 10), whose free outer leg connected to one another and at the connection point the holder (32) for an insertable Welding electrode (37) and in the middle of one E has a connection (36) for Welding power supply, that also a receiving device in the stable lower part in the form of a frame (Fig. 7 to 9) for the resonator elements and pincer-shaped Gripper elements (24a, 24b) are provided for the individual resonator elements (5, 10) are, as well as between these spacers (19, 20) between the individual resonators intervene and to determine the position of the resonators with one another before welding serve with the coupling wires. 2. Apparatus according to claim 1, d a d u r c h g e -k e n n z e i c h n e t that the gripper elements (24a, 24b) by an eccentric shaft (13) for all resonators (5, 10) are operated together, through which also electrical Transmitter elements (48) are operated simultaneously in the form of switches. 3. Device according to one of claims 1 or 2, d a d u r c h g it is not shown that spring claws (21) at the ends of the row of resonators are provided that the resonator elements after the locking of the receiving frame for the resonator elements press against each other and against the spacers (19, 20). 4. Device according to one of the preceding claims, d a d u r c h g e k e n n n z e i c h n e t that for the guidance of the lower coupling wire (11) and the upper coupling wires (6, 7) between the resonators wire holders (29) are provided in the form of narrow leaflets with a U-shaped recess, wherein the U-shaped recess is bent so that the axes of the coupling wires to System of the upper coupling wire to align with the side wall of the U and that for the installation of the upper coupling wire on this side wall of the U in the narrow leaflet (29) Magnetic elements (30) are used. 5. Device according to one of the preceding claims, d a d u r c h g e k e n n n z e i c h n e t that the welding electrodes (37) for the individual Welds have different shapes (Figures 14, 15, 16). 6. Device according to one of the preceding claims, d a d u r c h e k e n n n n z e i c h n e t that roughly in the middle of the arrangement a lever-shaped Spacer (43) is provided through which the upper coupling wires (6, 7) on the required distance can be maintained after inserting the lower coupling wire and the resonator element can be pivoted in by means of the eccentric shaft.