JP3893125B2 - Variable pressure welding head - Google Patents

Description

  The present invention relates to a resistance welding weld head, and more particularly, to a variable pressure welding head having a relatively low pressure.

  Conventionally, in resistance welding, it is important to control the welding current as well as the control of the pressing force to the welded member by welding electrodes. When welding leads for input and output to the electrodes of electrical parts, printed wiring A device for controlling the pressing force has also been devised in the case where a repair member is assigned to the disconnection portion of the plate and the repair member is welded to the circuit pattern on both sides of the disconnection portion.

  As an example of a welding operation by resistance welding, a welding state in the repair of a broken printed wiring board will be described with reference to FIG. In FIG. 8, 101 is a printed wiring board, 102 is a circuit pattern formed on the printed wiring board 101, 104 is a repair member, and 105 is an electrode assembly.

  Here, the printed wiring board 101 is placed on the stage 103 so as not to be displaced, and the stage 103 is moved in the X direction and the Y direction on the horizontal plane so that the disconnected portion 102A is located immediately below the electrode assembly 105. Perform positioning operation. Further, there is a case where it rotates in the θ direction in order to make the posture on the horizontal plane a predetermined angle. After positioning, the repair member 104 is applied to the disconnection location 102A, and the circuit pattern 102 and the repair material 104 on both sides of the disconnection location 102A are welded at the positions 104A and 104B shown in FIG.

  In the electrode assembly 105, as shown in FIG. 8B, a pair of electrodes 105A and 105B are arranged with a gap 105C interposed between them, and after pressing the repair member 104 as a member to be welded with the tips of both electrodes, A potential difference is applied to both electrodes by the power supply means that does not, and a current flows through the circuit pattern 102 and the repair member 104 by this potential difference to form a nugget, thereby performing resistance welding.

  As described above, even in such welding, the control of the pressure applied to the member to be welded has been devised conventionally. For example, as disclosed in Patent Document 1, the pressure is variably controlled by combining the lever members. There is technology to do. This technique is in principle as shown in FIG.

  In FIG. 9, 201 is an outer flange of the welding head, 202 is a base, 203 is a first lever member, 204 is a first fulcrum, 205 is a weight, 206 is an abutting member, 207 is a second lever member, and 208 is The second fulcrum, 209 is an electrode assembly, 210 is a stopper, and 211 is a member to be welded.

  Here, the outer flange 201 of the welding head is fixed at a predetermined height above the member to be welded, and the base 202 is fixed to the inner surface. A first lever member 203 is rotatably extended from a first fulcrum 204 provided on the base 202, and a weight 205 is disposed at the tip of the first lever member 203. Has been.

  Further, the first lever member 203 has a shape in which a male screw is cut into a round bar. A contact member 206 having a roller at a lower end is screwed into the male screw, and the first lever member 203 is centered on an axis. The contact member 206 is moved in the direction indicated by the arrow A shown in FIG. 9A by rotating the screw (rotating the male screw), so that the first fulcrum 204 and the contact member 206 can be adjusted to an arbitrary interval. I have to. Further, a second lever member 207 is rotatably extended from a second fulcrum 208 provided on the base 202, and an electrode assembly 209 is fixed to the tip of the second lever member. .

  The stopper 210 supports the second lever member 207 from below as shown in FIG. 9A except during welding. However, since the operator moves the stopper 210 downward during welding, the electrode assembly 209 is welded. Contact the member 211. At this time, the tip of the electrode assembly 209 is connected to the load of the second lever member 207 and the electrode assembly 209, the load of the contact member 206 itself, and the first lever member 203 and the weight 205 transmitted through the contact member 206. The member to be welded 211 is pressed with a pressing force applied with a load of. Further, at this time, a predetermined pressing force can be obtained by adjusting the distance between the first fulcrum 204 and the contact member 206 (dimension a shown in FIG. 9B) to a predetermined distance.

Japanese Examined Patent Publication No. 42-15296 (first page, FIG. 1)

  However, even when the electrode assembly 209 is within the operation range described above, as shown in FIG. 9B, the electrode tip contacts the welded member 211 at the lower end of the entire operation range, and FIG. ), The angle of the first and second lever members is different from the case where the tip of the electrode is in contact with the member to be welded 211 in the upper part of the entire operating range, and the applied pressure deviates from a predetermined value. .

  In order to avoid this, it is very difficult and troublesome for the operator to accurately adjust the vertical position of the entire welding head in accordance with the thickness of the member to be welded 211. Furthermore, even if the members to be welded 211 are of the same type, if the thickness varies, it is not practical to adjust the position of the welding head up and down accordingly.

  In addition, in the conventional configuration described above, the tip of the electrode of the electrode assembly 209 operates while drawing an arcuate locus, so that the height of the upper surface of the member to be welded 211 fluctuates, so There is a problem that the contact position is shifted. For example, the circuit pattern of a printed wiring board introduced in the description of the prior art has been reduced to a line width of about 25 μm due to the recent demand for high-density mounting. In the case of welding such a thin wire, a positional deviation of about 10 μm greatly affects the welding quality.

  Furthermore, since the tip of the electrode moves along an arcuate locus, there is a problem in that the surface to be contacted with the workpiece 211 at the tip of the electrode does not always contact at the same angle. This phenomenon is referred to as “per piece” by those skilled in the art and greatly affects the welding quality and the life of the electrode. Therefore, close efforts such as polishing the tip after incorporating the electrode into the apparatus have been made. Securing parallelism at the time of contact between the surface to be contacted and the surface of the member to be welded 211 cannot be expected from the above-described conventional configuration.

As a first aspect of the present invention, a first fulcrum is provided at one end and a weight is provided at the other end, and the distance between the first fulcrum and the weight is provided to be adjustable. A first lever member having a contact member, a second fulcrum at one end, a pressing portion at the other end, and a second lever member provided in a substantially parallel position with respect to the first lever member And these first
And an outer casing that houses the second lever member, and can move up and down with respect to the outer casing in the outer casing
At the same time as supporting the first and second fulcrums ,
A lift member for supporting the pressing portion from below, the is composed of a fixed electrode assembly in the pressing section, by Rukoto before SL lifting member to descend the outside in case, the pressing portion side front
The variable pressure welding head is provided in which the electrode assembly starts to contact the member to be welded while being supported by the lifting member from below .

Further, as a second aspect, a first fulcrum is provided at one end and a weight is provided at the other end, and the distance between the first fulcrum and the weight is provided to be adjustable. A first lever member having a contact member; a second fulcrum at one end; a pressing portion at the other end;
A second lever member which is disposed substantially parallel position with respect to the lever member, these first Oyo
And an outer casing that houses the second lever member, and a support that is movable up and down relative to the outer casing in the outer casing.
A lifting member is lifting rotatably supporting said first and second supporting point, it is composed of an electrode assembly which is supported on the elevating member in a movable state in the vertical linear direction, the previous SL lifting member
By lowering the outer casing, the electrode assembly is moved to the lower end of the movable range.
Provided is a variable pressure welding head characterized in that the electrode assembly starts to contact the member to be welded in a state where the electrode assembly is positioned and the electrode assembly presses the electrode assembly from above .

  According to the first aspect of the present invention, the tilt angle of the first and second lever members at the start of contact can be made the same regardless of the position where the electrode tip contacts the workpiece. Therefore, by supplying a welding current immediately after contact, it becomes possible to always obtain a stable pressing force even when there is a variation in the thickness of the member to be welded or a variation in the setting of the vertical position of the welding head. Stable welding quality can be obtained.

  Further, even if the electrode tip has a circular arc-like locus as in the first aspect of the present invention, the inclination angle of the second lever member at the start of contact between the electrode tip and the member to be welded is constant. Therefore, the parallelism immediately after contact between the surface to be welded at the electrode tip and the surface of the welded member is maintained, and stable welding quality is obtained.

  Furthermore, even if the electrode tip has a circular arc-like locus as in the present invention, since the angle of the second lever member at the start of contact between the electrode tip and the member to be welded is constant, The welding position is always constant, and misalignment is difficult to occur.

  Further, according to the second aspect of the present invention, it is possible to always keep the surface to be in contact with the member to be welded at the electrode tip as well as the contact start time of the electrode tip and the member to be welded at a constant angle, It is possible to more reliably avoid the one-sided contact as described above.

  In addition, according to the second aspect of the present invention, not only when the contact between the electrode tip and the member to be welded starts but also when the elevating member sinks over time and the second lever member is inclined, the electrode tip Therefore, the lateral welding force is not applied to the welded member after welding, and the welding quality of the fine welding work is further improved.

  FIG. 5 is an overall view of a welding apparatus using a variable pressure welding head according to the present invention. In this figure, 1 is a welding head, 51 is a support for holding the welding head, 52 is a stage for placing and positioning a member to be welded, 53 is a frame, and 54 is a foot switch. The welding head 1 is covered with an outer casing 2 and the electrode assembly 4 is exposed at the tip. The dial 3 is also exposed from the side surface of the outer casing 2. In this figure, the power supply unit, the control unit, and the operation unit are omitted.

  The operator fixes the welding head 1 to the support column 51 at an appropriate height and places the member to be welded on the stage 52. Then, the welding operation is started by stepping on the foot switch 54 after positioning the welding portion directly under the electrode tip by driving the stage 52.

  Next, the welding operation will be described in detail with reference to FIGS. 1 and 2 are schematic sectional views of the welding head showing the first aspect of the present invention, and FIGS. 3 and 4 are schematic sectional views of the welding head showing the second aspect of the present invention. In FIG. 1, 2 is an outer cage, 4 is an electrode assembly, 5 is a first lever member, 6 is a first fulcrum, 7 is a weight, 8 is a contact member, 9 is a second lever member, and 10 is a second lever. , 11 is a lifting member, 12 is a stopper, and 211 is a member to be welded.

  Here, the first lever member 5 has a shape in which a male screw is cut into a round bar, the contact member 8 has a roller at the lower end, and the upper portion is screwed into the male screw of the first lever member 5. The dial 3 shown in FIG. 5 has a central axis at the position of the first fulcrum 6, and is interlocked with a first bevel gear (not shown) arranged on the same axis as this. Further, a second bevel gear (not shown) meshed with the first bevel gear in a direction perpendicular to the first bevel gear is fixed on the same axis as the first lever member.

  In this configuration, the first bevel gear is rotated by rotating the dial 3, and the second bevel gear engaged with the dial 3 is rotated, whereby the first lever member 5 is rotated about its own axis. On the other hand, the second lever member 9 is a member having a flat surface on the upper surface side, and since the roller at the lower end of the contact member 8 is in contact with the flat portion of the second lever member 9, the contact member 8 is It does not rotate around the axis of the first lever member 5.

  Therefore, by rotating the dial 3, the contact member 8 screwed into the first lever member 5 can be moved in the axial direction of the first lever member 5 (the direction of arrow C). As a result, the total mass of the first lever member 5, the weight 7, and the contact member 8 can be transmitted to the second lever member 9 as a radius variable moment with reference to the fulcrum 6.

  The second lever member 9 has a second fulcrum 10 at one end and a pressing portion 9A at the other end, and the electrode assembly 4 is fixed to the pressing portion 9A. In the state of FIG. 1A, the pressing portion 9 </ b> A side of the second lever member 9 is supported from below by the end portion 11 </ b> A of the elevating member 11. The elevating member 11 is provided with the first fulcrum 6 and the second fulcrum 10 so as not to move relative to each other, and is supported by the outer casing 2 so as to be movable up and down by a linear guide 13 comprising a slide rail 13A and a slide block 13B. ing. Further, in the state of FIG. 9A, the stopper 12 supports the elevating member 11 from below. This state is a standby state before the welding operation.

  Next, when the preparation for welding is completed, the operator lowers the stopper 12 and starts the welding operation. When the stopper 12 is lowered, as shown in FIG. 1B or FIG. 1C, the first lever member 5 is moved as the elevating member 11 supported vertically by the linear guide 13 moves downward. The second lever member 9 also moves downward without changing its posture.

  Here, FIG. 1B shows a case where the member to be welded 211 is relatively below, and FIG. 1C shows a case where the member to be welded 211 is relatively above. In both cases, the operation of bringing the electrode tip into contact with the surface of the member to be welded 211 is realized in a state in which the postures of the first lever member 5, the second lever member 9, and the electrode assembly 4 do not change.

  Next, immediately after these states, that is, when the end portion 11A of the elevating member 11 is separated from the second lever member 9, a voltage is applied from the power supply means (not shown) to the electrode assembly 4, and welding is performed. In the case of this embodiment, the energization time for welding is about 50 milliseconds.

  When the time further elapses, the state shown in FIG. 1B is as shown in FIG. 2B2, and the state shown in FIG. 1C is as shown in FIG. 2C2. Here, in FIG. 2B2 where the member to be welded 211 is relatively below, even when the elevating member 11 reaches the lower end of the operating range, the first lever member 5 and the second lever member 9 are If the member to be welded 211 is relatively upward, the first lever member 5 and the second lever member 9 are largely inclined as shown in FIG. 2 (c2).

  In the case of the present embodiment, the welding operation is started when the operator operates the foot switch 54 with his / her foot. The state shown in FIG. 2 (b2) or FIG. 2 (c2) after the foot switch 54 is depressed. Usually, a time of 500 milliseconds or more passes. However, as described above, the time during which the welding current flows, in other words, the substantial welding time is about 50 milliseconds. That is, substantial welding is performed immediately after the state shown in FIGS. 1B and 1C, and the posture change of the first and second lever members is completed within a short time.

  Next, a second aspect of the present invention will be described with reference to FIGS. In FIG. 3, the electrode assembly 4 is supported on the end portion 15A of the elevating member 15 by a linear guide 14 including a slide rail 14A and a slide block 14B. Further, the pressing portion 16A of the second lever member 16 is in contact with the upper surface of the electrode assembly 4, and the electrode assembly 4 is moved by the linear guide 14 in the state shown in FIG. Located at the lower end of the vertical movement range. Further, since the other members are equivalent to the configuration of the first aspect described with reference to FIGS. 1 and 2, description will be made using the same reference numerals.

  Next, the operation of the welding operation will be described. As shown in FIG. 3A, when the member to be welded 211 is positioned and ready for the welding operation, the operator lowers the stopper 12 and starts the welding operation. When the stopper 12 is lowered, as shown in FIG. 3 (b) or FIG. 3 (c), the first lever member 5 is moved as the elevating member 15 supported vertically by the linear guide 13 moves downward. The second lever member 16 also moves downward without changing the respective postures.

  Here, FIG. 3B shows a case where the member to be welded 211 is relatively below, and FIG. 3C shows a case where the member to be welded is relatively above. In both cases, the operation of bringing the electrode tip into contact with the surface of the member to be welded 211 is realized in a state in which the postures of the first lever member 5, the second lever member 16, and the electrode assembly 4 do not change.

  Next, immediately after these states, that is, when the elevating member 15 starts to descend without lowering the electrode assembly 4, a voltage is applied to the electrode assembly 4 from a power supply means (not shown), and welding is performed. As time further elapses, the state shown in FIG. 3B becomes as shown in FIG. 4B2, and the state shown in FIG. 3C becomes as shown in FIG. 4C2.

  In FIG. 4B2 where the member to be welded 211 is relatively below, the first lever member 5 and the second lever member 16 are in the state where the elevating member 15 has reached the lower end of the operating range. If the member to be welded 211 is relatively upward, the first lever member 5 and the second lever member 16 are largely inclined as shown in FIG. 4 (c2).

  However, according to the second mode, as shown in FIGS. 4 (b2) and 4 (c2), even when the elevating member 15 reaches the lower end of the operating range, the posture of the electrode assembly 4, that is, the angle viewed from the side. Does not change and is maintained even when the height of the upper surface of the member to be welded 211 is different. That is, even after the energization is performed and the substantial welding is completed, the workpiece 211 is not subjected to a lateral force by the electrode tip.

  Next, based on FIG. 6 and FIG. 7, the detailed structure of the Example which concerns on the 2nd aspect of this invention is demonstrated. In FIG. 6, 17 is a base for ensuring the structural strength of the entire welding head, 18 is an insulating plate, 19 is a first power supply plate, and 20 is a flexible material made of a material in which thin copper alloy plates are stacked. 2 is a power feeding block, 21 is a third power feeding plate which is also flexible, 23 is a wire interlocking with the foot switch 54 shown in FIG. 5, 24 is a compression coil spring, 25 is a plunger, 26 is a first bevel gear, and 27 is a second bevel gear.

  First, the operator sets the pressing force of the electrode during welding by turning the dial 3 shown in FIG. The first bevel gear 26 is interlocked with the dial 3, and when the dial 3 is turned, the second bevel gear 27 meshed with the first bevel gear 26 is also rotated. Here, the first lever member 5 is supported so as to be rotatable around the first fulcrum 6 like a watch hand as viewed in FIG. 6, and is also supported so as to be rotatable about its own axis. ing.

  Accordingly, when the second bevel gear 27 fixed to the first lever member 5 is rotated, the male screw carved on the surface of the first lever member 5 is rotated, and the abutting member screwed into this is engaged. 8 moves in the axial direction of the first lever member 5. In this way, the pressing force during welding is set and the member to be welded 211 is positioned, and then the operator steps on the foot switch 54 shown in FIG. 5 to start the welding operation.

  When the foot switch 54 is stepped on, the wire 23 interlocked therewith pulls the plunger 25 against the repulsive force of the compression coil spring 24. This operation will be described with reference to a detailed view of the stopper 12 pulled out in the upper part of FIG. The stopper 12 is supported by the base 17 at a fulcrum 12A (the support portion is not shown), and is rotated around the fulcrum 12A when the plunger 25 pulls the force application point 12B.

  Along with this, the roller 12C also rotates about the fulcrum 12A, and the elevating member 15 supported by the roller 12C from the protruding portion 15B from below moves downward. The elevating member 15 is supported by the linear guide 13 so as to be movable in the vertical direction, and the slide rail 13A of the linear guide 13 is fixed to the base 17 (the illustration of the fixing portion is omitted).

  When the elevating member 15 moves downward, the first lever member 5 and the second lever member 16 move downward without changing their postures, and at the same time, the electrode assembly 4 also moves downward, and FIG. As shown in (a), the electrode tip contacts the surface of the member to be welded 211. When the elevating member 15 further moves downward, the electrode assembly 4 stops at this position while being regulated by the linear guide 14, and only the elevating member 15 continues to descend. As a result, the pressing portion 16A presses the electrode assembly 4 downward with a predetermined pressing force. The sum of the pressing force and the weight of the electrode assembly 4 is set as the pressing force during welding.

  When the pressing force set in this way is applied to the member to be welded 211, a voltage is applied to the first power supply plate 19 from a power supply means (not shown). The first power feeding plate 19 is fixed on the base 17 via an insulating plate 18, and the applied voltage is transmitted to the second power feeding plate 20. The second power supply plate 20 absorbs the relative displacement between the base 17 and the elevating member 15 with a slight reaction force due to its flexibility.

  The voltage transmitted to the second power feeding plate 20 is transmitted to the third power feeding plate 22 via a power feeding block 21 that is electrically insulated and fixed to the elevating means 15. The third power supply plate 22 absorbs the relative displacement between the elevating member 15 and the electrode assembly 4 with a slight reaction force due to its flexibility. The voltage transmitted to the third power supply plate 22 is transmitted to the electrode of the electrode assembly 4.

  Here, only one first power supply plate 19, second power supply plate 20, power supply block 21, third power supply plate 22, and electrode are depicted as side views in FIGS. 6 and 7, but in practice, As shown in the figure, voltage application is realized by providing a pair in the front-rear direction.

  Even after the energization and the substantial welding are performed in this manner, the downward movement of the elevating member 15 continues, and the first lever member 5 and the second lever member 16 are as shown in FIG. Although each tilts, the electrode assembly 4 does not tilt and does not move laterally.

Sectional schematic diagram showing an embodiment according to the first aspect of the present invention Sectional schematic diagram showing an embodiment according to the first aspect of the present invention Sectional schematic diagram which shows embodiment which concerns on the 2nd aspect of this invention. Sectional schematic diagram which shows embodiment which concerns on the 2nd aspect of this invention. The side view showing the device of one embodiment of the present invention. Sectional drawing which shows the Example which concerns on the 2nd aspect of this invention Sectional drawing which shows the Example which concerns on the 2nd aspect of this invention Perspective view and sectional view showing conventional technology Cross-sectional schematic diagram showing conventional technology

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding head 2 Outer rod 3 Dial 4 Electrode assembly 5 1st lever member 6 1st fulcrum 7 Weight 8 Contact member 9, 16 2nd lever member 10 2nd fulcrum 11, 15 Lifting member 12 Stopper 13, 14 Linear guide

Claims (2)

A welding head provided with an electrode for resistance welding,
A first fulcrum at one end, a weight at the other end, and a contact member provided between the first fulcrum and the weight so that an interval between the first fulcrum is adjustable. A lever member, a second fulcrum at one end, a pressing portion at the other end, a second lever member provided in a substantially parallel position with respect to the first lever member, and the first and second Storing the lever member
And the first and second outer casings supported in such a manner as to be movable up and down with respect to the outer casing.
When supporting the fulcrum consists of simultaneously and temperature <br/> descending member for supporting the pressing portion side of the second lever member from below, a fixed electrode assembly in the pressing portion, the previous SL lifting member Above
By descending the outer casing, the pressing part side is supported by the lifting member from below.
The variable pressure welding head , wherein the electrode assembly starts contact with the member to be welded in a state where the welding is performed. A welding head provided with an electrode for resistance welding,
A first fulcrum at one end, a weight at the other end, and a contact member provided between the first fulcrum and the weight so that an interval between the first fulcrum is adjustable. A lever member, a second fulcrum at one end, a pressing portion at the other end, a second lever member provided in a substantially parallel position with respect to the first lever member, and the first and second Storing the lever member
And the first and second outer casings supported in such a manner as to be movable up and down with respect to the outer casing.
A lifting member for supporting the fulcrum is composed of an electrode assembly which is supported on the elevating member in a movable state in the vertical linear direction, the front SL lifting member is lowered to the outer within the housing
The electrode assembly is positioned at the lower end of the movable range, and the pressing portion is
The variable pressure welding head , wherein the electrode assembly starts contact with a member to be welded in a state where the electrode assembly is pressed from above .

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