JP2006263823A - Spot welding gun - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe, inexpensive and small spot welding gun with a simple structure. <P>SOLUTION: A spot welding gun is provided with first and second arms 14 and 16 which are turnably and pivotably supported around a common support shaft 12, a first electrode 18 fitted to one end of the first arm 14, a second electrode 20 which is fitted to one end of the second arm 16 and set to be able to abut on the first electrode 18, and a drive mechanism 22 which is interposed between the first arm 14 and the second arm 16 to open/close the space between the first and second electrodes 18 and 20. The drive mechanism 22 is installed between the other end of the first arm 14 and a section which is located between the support shaft 12 of the second arm 16 and a tip of the second arm 16 to which the second electrode 20 is fitted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a spot welding gun for pressurizing a material to be welded by a pair of electrodes, supplying a large current to the welded material within a short time, and melting and joining the welding local parts by resistance heating. In particular, the present invention relates to a so-called X-type spot welding gun in which a pair of arms each having an electrode attached to each tip is pivotally supported around a support shaft.

  Conventionally, spot welding has been widely used as a kind of resistance welding in order to weld between thin metal plates. In particular, spot welding has a possibility of welding between various metals, a point with little thermal influence, and since welding work is performed almost automatically, it is uniform without introducing individual differences among workers. This is a welding technique that is very commonly used as a technique that is excellent in adapting to automation in automobile manufacturing technology, particularly from the point of obtaining welding results.

  As this spot welding machine, a spot welding gun is known which is configured to be easily operated by an operator or attached to the tip of a robot arm for easy automation. As is well known, the spot welding guns are roughly classified into C type guns and X type guns.

  Here, for example, in the case of an X-type gun, from the viewpoint of workability, conventionally, during the welding operation, the movement strokes of both electrodes are set to be short and restricted so as to open only narrowly, thereby achieving an efficient welding operation. On the other hand, at the start or end of the welding operation, the moving strokes of both electrodes are set long and wide open so that a reliable set operation or end operation is performed.

  In order to achieve such a two-stage stroke, for example, as a conventional drive mechanism for opening and closing both arms, a double cylinder structure shown in FIGS. 14 to 16 or a member for regulating the piston stroke shown in Patent Document 1 is used. There is a known structure in which the cylinder is provided outside the cylinder.

  The structure of the X-type gun according to the conventional technology of the double cylinder type will be described briefly. Although not shown in detail, the first and second arms are provided so as to be rotatable around a common support shaft. The first and second electrodes are attached to the tips of the first and second arms so as to be in contact with each other. A drive mechanism 70 having a double cylinder structure is interposed between the first and second arms so as to open and close both of the first and second arms so as to contact and separate the first and second electrodes.

  Here, the drive mechanism 70 is configured to have a double cylinder structure as described above. Specifically, as shown in FIG. 14, the outer first cylinder 72 is formed in a sealed state, In this first cylinder 72, a second cylinder 74 whose left side surface in the figure is fully opened is slidably accommodated, and in this second cylinder 74, a piston 76 is slidably accommodated. The piston rod 78 is integrally attached to the piston 76 so as to extend leftward in the drawing, and the piston rod 78 is attached to the first cylinder 72 via the open side surface on the left side of the second cylinder 74 in the drawing. The structure of taking out from the left side in the figure is adopted.

  And the 1st air port 80 is provided in the right side in the figure on the opposite side to the side in which the piston rod 78 of the 1st cylinder 72 was provided, and this 1st air port 80 is used as the 1st air port 80. Compressed air as working fluid is sucked into and exhausted from a first cylinder chamber 82 defined by a space between the right side surface of the cylinder 72 and the second cylinder 74, and the piston rod of the first cylinder 72 A second air port 84 is provided on the left side in the drawing on the side where 78 is provided, and the space between the left side of the first cylinder 72 and the piston 76 is provided via the second air port 84. Compressed air as a working fluid is sucked into and exhausted from the second cylinder chamber 90 defined, and the third air port is opened on the right side in the figure of the piston 76 and penetrates the cylinder rod 78. 88. Via a third air port 88, compressed air as a working fluid is sucked and exhausted into a third cylinder chamber 86 defined from a space between the second cylinder 74 and the piston 76. ing.

In the conventional double cylinder structure X-type gun configured as described above,
(1) During the pressurizing operation for executing the welding operation, as shown in FIG. 14, the compressed air is supplied to the first and third cylinder chambers 82 via the first and third air ports 80 and 88. 86, the piston rod 78 is projected to the maximum, and the first and second electrodes 66, 68 are pressurized with the work piece interposed therebetween,
(2) When the first and second electrodes 66 and 68 are separated from each other by moving the welding position or the like, as shown in FIG. 15, from the state shown in FIG. In a state where the introduction of compressed air is stopped and communicated with the atmosphere, compressed air is introduced from the second air port 84 into the second cylinder chamber 90, and the piston rod 78 is limited to the second cylinder chamber 90. Pull in and move, open a small gap between the first and second electrodes 66, 68, move the welding position,
(3) When the first and second electrodes 66 and 68 are separated from each other by setting or removing the X-type gun from the workpiece, as shown in FIG. 16, from the state shown in FIG. The introduction of the compressed air to the first air port 80 is stopped to communicate with the atmosphere, the second cylinder 74 is drawn and moved over the entire area of the first cylinder chamber 82, and the first and second electrodes 66, 68 so that there is a large gap between
To work.

  In this way, the separation operation of the first and second electrodes 66 and 68 is performed with two types of strokes, long and short, so that the welding operation can be performed efficiently. Yes.

Further, the structure of the spot welding gun disclosed in Patent Document 1 in which a member for regulating the stroke of the piston is provided outside the cylinder will be briefly described. The upper arm, the lower arm, and the upper and lower arms can be freely opened and closed. A spot welding gun comprising: a pivot shaft for pivot connection; an electrode tip facing the tips of the upper and lower arms; and a pressure open / close cylinder erected at the rear ends of the upper and lower arms. In order to change the stroke of the piston rod in an exposed state between the connecting member and the upper end surface of the cylinder, connected to the rear end of the upper arm through a connecting member provided at the tip of the piston rod extending from Spacers are provided.
ACT 59-49482

  However, the drive mechanism that achieves the two-stage stroke according to the prior art as described above has a complicated structure such that two cylinders must be provided, and three air switching valves are required. It is pointed out that the cost is high.

  In addition, in the structure in which the spacer as a regulating member is exposed outside the cylinder as in Patent Document 1, the regulating member moves with a strong force during the welding operation. There is a risk that an operator's fingers or the like may be pinched between the welding gun body and damage, and improvement is desired from the viewpoint of risk prevention. Further, since a pressure open / close cylinder as a drive mechanism is installed on the rear end portion of the upper arm and the lower arm, it has been pointed out that the size of the entire spot welding gun is increased.

  The present invention has been made to solve the above-described problems, and a main object of the present invention is to achieve a two-stage stroke with a simple structure, a safe, inexpensive, and compact structure. It is to provide a spot welding gun.

  In order to solve the above-described problems and achieve the object, according to the spot welding gun according to the present invention, the first and the second are pivotally supported around a common support shaft. Two arms, a first electrode attached to one end of the first arm, and a second electrode attached to one end of the second arm and configured to be able to contact the first electrode. And a driving means interposed between the first arm and the second arm for opening and closing between the first and second electrodes, the driving means comprising: It is constructed between the other end of the first arm and a portion between the support shaft of the second arm and the one end of the second arm.

  In the spot welding gun according to the present invention, the drive means is rotatably connected to the second arm by a connection mechanism, and the connection mechanism is connected to the drive gun. A guide pin rotatably attached to the tip of the mechanism, and a long hole formed in a portion between the support shaft of the second arm and the one end of the second arm, A guide pin is slidably inserted into the elongated hole.

  According to a spot welding gun according to the present invention, the elongated hole extends along a direction intersecting the advancing / retreating direction of the drive mechanism, and according to the advance / retreat of the drive mechanism. Then, the second arm rotates when the guide pin moves through the elongated hole.

  According to a spot welding gun according to the present invention, the driving means includes a cylinder attached to the first arm, a slidably housed in the cylinder, and a tip portion. Comprises a piston attached to the second arm via the coupling mechanism.

  The spot welding gun according to the present invention is the spot welding gun according to claim 5, wherein the driving means is provided between the cylinder and the piston in the cylinder when the two electrodes are separated from each other. A restricting means for restricting the moving stroke is interposed, and a small interval is defined between the first and second electrodes in a state where the moving stroke of the piston is restricted by the restricting means. A large interval is defined in a state where the movement stroke of the piston is not regulated.

  According to a sixth aspect of the present invention, the spot welding gun is characterized in that the driving means includes an operating portion for operating the regulating means outside the cylinder.

  In the spot welding gun according to the present invention, the restricting means is capable of rotating around the central axis of the cylinder and immovable along the central axis. And a regulating member formed in a flat cross section, and the piston is formed to extend along the central axis in a state where the piston is opened at an end surface on the side where the regulating member is disposed, The cross-sectional shape permits the insertion of the restricting member when the restricting member is at a predetermined first angular position, and the restricting member is at a second angular position different from the first angular position. And a hole formed to prevent insertion of the restricting member, and when the restricting member is at the first angular position, the movement stroke of the piston is not restricted, and the first Second angle different from 1 angular position When in position, the movement stroke of the piston is characterized by a state is restricted.

  In the spot welding gun according to the present invention, the restriction member has an end portion that protrudes to the outside through the cylinder, and the protruding end portion is determined by an operator. It is characterized by being made rotatable.

  Further, according to the spot welding gun according to the present invention, a lever extending along a direction substantially orthogonal to the protruding end portion of the regulating member is integrally attached to the protruding end portion of the regulating member, The operator is characterized by changing the degree of opening between the first and second electrodes by switching the restriction or release of the movement stroke of the piston by rotating the lever.

  In the spot welding gun according to the present invention, the regulating member is urged to rotate from the first angular position to the second angular position by the urging member. And is elastically held at the second angular position.

  According to the present invention, a spot welding gun having a simple configuration, an inexpensive and small configuration for achieving a two-stage stroke is provided.

  Hereinafter, an embodiment (one example) of a spot welding gun according to the present invention will be described in detail with reference to FIGS. 1 to 12 of the accompanying drawings.

  As shown in FIG. 1 in a state where the pressure is applied during the welding operation, the spot welding gun 10 is a handy type X-type gun that is gripped by an operator and rotates around a common support shaft 12. First and second arms 14 and 16 that are freely supported, a first electrode 18 attached to the tip (one end) of the first arm 14, and a tip of the second arm 16 ( A first electrode 18 and a second electrode 20 set so as to be in contact with the first electrode 18, and the first arm 14 and the second arm 16. And a drive mechanism 22 for opening and closing between the two electrodes 18 and 20.

  The first and second arms 14 and 16 are respectively attached with grip ends 24 and 26 which are respectively held by both hands of the operator. Although not shown, the grip ends 24 and 26 are respectively shown. 26 is connected to an electric cable for energizing between the corresponding electrodes 18 and 20.

  Here, as shown in the enlarged state in FIG. 2, the drive mechanism 22 described above is slidably housed in the cylinder 28 attached to the first arm 14 and slidable in the cylinder 28. A piston 30 attached to the second arm 16, and a moving stroke in the retracting direction of the piston 30 (ie, separation of the first and second electrodes 18, 20) between the cylinder 28 and the piston 30. A restriction mechanism 32 is provided for restricting the time stroke) to be releasable. The drive mechanism 22 is installed between the other end of the first arm 14 and a portion between the support shaft 12 and the tip of the second arm 16.

  More specifically, the cylinder 28 is configured by a cylindrical casing with an inside sealed, and is fixed by being integrally attached to the other end of the first arm 14. As shown in FIGS. 3 and 4, the piston 30 is slidably provided on the inner circumferential surface of the cylinder 28 while maintaining an airtight state. A piston body 30A that is separated into a second cylinder chamber 34B on the left side in the figure, and the piston arm 30A airtightly penetrates the left side wall of the cylinder 28 in the figure to the second arm 16. The piston rod 30 </ b> B extends integrally, and the tip of the piston rod 30 </ b> B is connected to the second arm 16 via a connecting mechanism 36 so as to be rotatable. The connection mechanism 36 will be described later.

  A first air port 38 for intake / exhaust of compressed air as a working fluid is formed in the first cylinder chamber 34A on the right side wall of the cylinder 28 in the drawing. On the wall, a second air port 40 is formed in the second cylinder chamber 34B for intake / exhaust of compressed air as working fluid. The first air port 38 is connected to a compression pump or the atmosphere via a switching valve (not shown) so as to be switchable, and the second air port 40 is switched to the compression pump or the atmosphere via the switching valve described above. Connected as possible.

  Since the cylinder 28 and the compression pump are thus connected via the switching valve, the switching valve connects the first cylinder chamber 34A and the compression pump, and connects the second cylinder chamber 34B and the atmosphere. In this state, the piston 30 is moved and biased to the left in the drawing, and as shown in FIG. 1, the first and second arms 14 and 16 are rotated so as to approach each other, and the first and second electrodes 18 are moved. , 20 are brought to the pressing position where they are pressed against each other.

  On the other hand, from the pressure position shown in FIG. 1, the switching valve connects the first cylinder chamber 34A and the atmosphere, and connects the second cylinder chamber 34B and the compression pump. The first and second electrodes 18 and 20 are rotationally biased in directions away from each other.

  Here, the restriction mechanism 32 described above constitutes one of the features of the present invention. When the first and second electrodes 18 and 20 are separated from each other, the pull-in operation (first and second) of the piston 30 is performed. The movement of the first electrode 18 and the second electrode 18 and the second electrode 18 and the second electrode 18 and the second electrode 18 and the second electrode 18 and the second electrode 18 and the second electrode 18, respectively. The movement stroke of the piston 30 is not restricted, so that the gap between the first and second electrodes 18 and 20 is allowed to become a large interval. A step moving stroke, that is, a two step moving stroke during the separating operation between the first and second electrodes 18 and 20 is defined.

  More specifically, as shown in FIG. 2, the restricting mechanism 32 is provided on the right side wall of the cylinder 28 in the drawing so as to be rotatable around the central axis thereof and along the central axis. Along with the central axis of the cylinder 28 in a state in which the regulating member 42 that is immovably attached and has a flat cross-sectional shape and the piston 30 described above is open to the end surface on the side where the regulating member 42 is disposed. When the regulating member 42 is at a predetermined first angular position, insertion of the regulating member 42 is permitted, and the regulating member 42 has a predetermined angular position. In the case of the second angular position that is different (biased) by an angle, for example, 90 degrees, it is configured to include a hole 44 that is formed so as to prevent insertion of the regulating member 42.

  Since the restricting mechanism 32 is configured in this way, when the restricting member 42 is in the first angular position, the retraction movement stroke of the piston 30 is not restricted, and accordingly, the first and second electrodes 18, When the gap between the two is allowed to be large, and when the second angular position is deviated by 90 degrees from the first angular position described above, the retraction movement stroke of the piston 30 is Therefore, when the first and second electrodes 18 and 20 are separated from each other, the gap between them is limited to a small interval.

  Here, the restricting member 42 as one component of the restricting mechanism 32 described above penetrates the right side wall in the drawing of the cylinder 28 as shown in FIGS. 5 and 6 in this embodiment. A mounting portion 42A that is mounted so as to be rotatable in such a state and is not movable along the central axis of the cylinder 28, and a regulating piece 42B that extends from the mounting portion 42A toward the hole 44. As is apparent from FIG. 4, the restriction piece 42 </ b> B is integrally formed and has a flat cross section, more specifically, a rectangular cross section.

  On the other hand, as is apparent from FIG. 2, the hole 44 as another component of the restriction mechanism 32 described above opens to the right end surface of the piston main body 30A in the drawing, and the attachment part 42A of the restriction member 42 described above. However, as shown in cross-sections in FIGS. 7 and 8 respectively, the large-diameter hole portion 44A formed with a predetermined depth so that it can be inserted at any angular position, Is formed continuously on the side, and opens to the bottom surface (left side surface in the drawing) of the large-diameter hole portion 44A, and the portions facing each other with respect to the diametrical direction are formed so as to narrow radially inward, The restricting piece 42B of the restricting member 42 described above is configured to include a restricting hole portion 44B that can be inserted only when the restricting piece 42B is in the first angular position.

  Here, in order to define the restriction hole portion 44B having the above-mentioned cross-sectional shape, a pair of bulging portions 30C and 30C facing each other in the diametrical direction are provided on the inner peripheral surface of the portion continuing to the large diameter hole portion 44A. It is integrally provided in a state where it bulges gently inward in the direction. In other words, the end portions on the opening side of the bulging portions 30C and 30C are in a state of projecting inward in the radial direction from the inner peripheral surface of the large-diameter hole portion 44A in a state that just constitutes a shoulder portion. It will be.

  In this embodiment, as shown in FIG. 4, the hole 44 is arranged in a state in which the restriction hole 44 </ b> B extends in the vertical direction in the drawing, and the restriction piece 42 </ b> B of the restriction member 42. In FIG. 4, the first angular position is defined in the state where it is in an upright state as indicated by a broken line. Therefore, the regulating piece 42B can be fitted into the regulating hole 44B, and the piston 30 The movement at the time of retraction is not restricted at all. On the other hand, the second angular position is defined in a state where the restricting piece 42B is rotated and biased by 90 degrees as shown by the one-dot chain line in FIG. The piece 42B engages with the shoulder portions of the bulging portions 30C and 30C defining the restriction hole portion 44B, and the movement stroke when the piston 30 is retracted is restricted.

  On the other hand, both the bulging portions 30C and 30C are formed integrally with the piston rod 30B. In this embodiment, since the piston 30 itself is formed as an aluminum casting, these bulging portions are formed. The parts 30C and 30C are naturally made of aluminum. For this reason, there is a possibility that the tip of the restricting piece 42B described above will be damaged if it strongly collides with the end surfaces (that is, the shoulders) of the bulging portions 30C, 30C.

  Therefore, in this embodiment, steel bolts 46, 46 are embedded in the end faces of the bulging portions 30C, 30C with their heads exposed. As a result, the movement of the tip of the regulating piece 42B is regulated in a state where the tip of the regulating piece 42B is in contact (collision) with the heads of these bolts 46, 46, and the bulging portions 30C, 30C can be surely damaged. Will be resolved.

  Further, the mounting portion 42A of the regulating member 42 described above has an end portion that protrudes to the outside through the right side wall of the cylinder 28 in the drawing, and this protruding end portion includes an end portion as shown in FIG. An operation lever 48 extending along a substantially orthogonal direction is integrally attached. Here, the regulating member 42 is moved by the biasing spring 50 from the first angular position (shown in FIG. 9) that defines the large interval described above to the second angular position (shown in FIG. 10) that defines a small interval. ) And is elastically held at this second angular position.

  Then, the operator switches the restriction or release of the movement stroke of the piston 30 by rotating the operation lever 48 to change the degree of opening (open position) between the first and second electrodes 18 and 20. Can be different.

  More specifically, when the operator does not operate the operation lever 48 at all, the operation lever 48 is elastically held at the second angular position by the urging force of the urging spring 50 as shown in FIG. In this state, the first and second electrodes 18 and 20 can be separated from each other only by a small distance (that is, a small open position). On the other hand, when the operator causes the operating lever 48 to be biased from the second angular position to the first angular position as shown in FIG. 9 against the biasing force of the biasing spring 50, The first and second electrodes 18 and 20 can be separated from each other with a large distance (that is, a large open position). When the operator releases his / her hand from the operation lever 48 at the first angular position, the operation lever 48 is automatically moved from the first angular position to the second angular position by the urging force of the urging spring 50. Needless to say, it will return.

  Next, the connection mechanism 36 for rotatably connecting the tip of the piston rod 30B to the second arm 16 will be described with reference to FIG. 2 again.

  The coupling mechanism 36 includes a guide pin 52 that is rotatably attached to the tip of the piston 30, and the support shaft 12 and the second shaft of the second arm 16 so that the guide pin 52 is slidably inserted. And an elongated hole 54 formed in a portion between the tip portion to which the electrode 20 is attached. Here, the long hole 54 is formed so as to extend along a direction intersecting the advancing / retreating direction of the piston 30, specifically, a direction orthogonal thereto.

  Since the coupling mechanism 36 is configured in this way, the guide pin 52 rotates the second arm 16 while moving in the elongated hole 54 according to the advancement and retreat of the piston 30, thereby The second arm 16 is reliably rotated around the support shaft 12 with respect to the first arm 14. That is, by this coupling mechanism 36, between the other end portion of the first arm 14 and a portion of the second arm 16 between the support shaft 12 and the tip end portion to which the second electrode 20 is attached. With the drive mechanism 22 installed, the second arm 16 is reliably rotated around the support shaft 12 with respect to the first arm 14 and the entire spot welding gun can be reduced in size.

  In the spot welding gun 10 configured as described above, the switching valve connects the first cylinder chamber 34A and the compression pump, and the switching valve connects the second cylinder chamber 34B and the atmosphere, so that the piston 30 is shifted to the left in the figure, and as shown in FIG. 1, the first and second electrodes 18 and 20 are brought to a pressurizing position where they are pressed against each other. In this pressurization position, a current of a predetermined voltage is passed between the first and second electrodes 18 and 20, so that the plates to be welded (not shown) sandwiched between the electrodes 18 and 20 are melted together. And will be welded.

  When the welding operation is temporarily interrupted from this pressure position and the welding position is changed, the operation lever 48 is maintained in the state shown in FIG. 10 (that is, the operation lever 48 is not operated at all), and the switching valve is operated. Are switched to connect the first cylinder chamber 34A and the atmosphere, and to connect the second cylinder chamber 34B and the compression pump, respectively. As a result, the piston 30 is moved and biased rightward in the figure, and the first and second electrodes 18 and 20 are rotationally biased in directions away from each other. Here, since the restricting member 42 is held at the second angular position, the restricting piece 42B of the restricting member 42 is an overhanging portion of the restricting hole 44B of the hole 44 as shown by a one-dot chain line in FIG. Is engaged with the heads of a pair of bolts 46, 46 embedded in the shoulders of the bulging portions 30C, 30C, and the movement stroke when the piston 30 is retracted is restricted.

  In this way, as shown in FIG. 11, a small open state in which the first and second electrodes 18 and 20 are separated by a small interval is defined. As a result, the operator can change the welding position within a short time, and the working efficiency is remarkably improved.

  On the other hand, when the welding operation is finished from the above-described pressurizing position and the spot welding gun 10 is removed from the welding position, the operation lever 48 is resisted against the biasing force of the biasing spring 50 from the state shown in FIG. Then, it is rotated clockwise in the drawing to bring it to the first angular position as shown in FIG. In this state, the switching valve performs switching so as to connect the first cylinder chamber 34A and the atmosphere, and connect the second cylinder chamber 34B and the compression pump, respectively.

  As a result, the piston 30 is moved and biased rightward in the figure, and the first and second electrodes 18 and 20 are rotationally biased in directions away from each other. Here, since the restricting member 42 is held at the first angular position, the restricting piece 42B of the restricting member 42 is a bulge that defines the restricting hole 44B of the hole 44 as shown by a broken line in FIG. It fits in the regulation hole 44B without engaging with the heads of the pair of bolts embedded in the shoulders of the protruding portions 30C and 30C. As a result, there is no restriction on the movement stroke when the piston 30 is retracted.

  In this way, as shown in FIG. 12, a large open state in which the first and second electrodes 18 and 20 are separated by a large distance is defined. As a result, the operator can remove the spot welding gun 10 from the welding position very easily, and the workability thereof is greatly improved.

  Needless to say, the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist of the present invention.

  For example, in the above-described embodiment, the cylinder 28 of the drive mechanism 22 is fixed to the first arm 14, and the piston 30 attached to the cylinder 28 so as to be able to advance and retract is rotated to the second arm 16 via the coupling mechanism 36. Although described so that it could move freely, this invention is not limited to such a structure, For example, by attaching the cylinder 28 to the 1st arm 14 so that rotation is possible, the front-end | tip of piston 30 is provided. Can be simply pivotably connected to the second arm 16.

  In the above-described embodiment, the compressed air as the working fluid is taken in and exhausted to the first and second cylinder chambers 34A and 34B via the first and second air ports 38 and 40 to the cylinder 28, respectively. As described above, the piston 30 is driven to advance and retract. However, the present invention is not limited to such a configuration, and the protrusion operation of the piston 30 (that is, the closing operation of both the electrodes 18 and 20) is performed. Although the above-described compressed air is used, the pull-in operation of the piston 30 (that is, the opening operation of both the electrodes 18 and 20) may be performed using an urging force of a return spring (not shown).

  In the above-described embodiment, the operation lever 48 has been described as being elastically held at the second angular position by the biasing force of the biasing spring 50. However, the present invention is limited to such a configuration. Instead, it may be configured to be elastically held alternatively at the first or second angular position by using a toggle spring or the like, or without using a spring, for example, friction system engagement. May be configured to hold the stop position. In the above-described embodiment, the spot welding gun is described as being applied to the X-type gun 10. However, the present invention is not limited to such an application example, for example, as shown in FIG. Thus, it goes without saying that the present invention can be applied to the C-type gun 60. The constituent elements of the C-type gun 60 shown in FIG. 13 are different only in the operation form of the pair of arms. To do.

  It is a front fragmentary sectional view shown in the state in a welding position (pressurization position) about the case where the structure of the spot welding gun concerning this invention is applied to X type.   It is front sectional drawing which takes out and shows a drive mechanism from the spot welding gun shown in FIG.   It is a front view which takes out and shows a piston from the drive mechanism shown in FIG.   It is a side view which shows the side surface shape of the piston shown in FIG.   It is a front view which takes out and shows the regulating member which constitutes a regulating mechanism.   It is a side view which shows the side surface shape of the control member shown in FIG.   FIG. 5 is a cross-sectional view showing the piston shown in FIG. 4 cut along the line XX in order to explain the shape of the hole.   FIG. 5 is a cross-sectional view showing the piston shown in FIG. 4 in a state cut along the line YY in order to explain the shape of the hole.   It is a side view which shows a cylinder in the state which has an operation lever in a 1st angular position.   It is a side view which shows a cylinder in the state which has an operation lever in a 2nd angular position.   It is a front view which shows a spot welding gun in the small open state which the 1st and 2nd electrode spaced apart by the small space | interval.   It is a front view which shows a spot welding gun in the large open state which the 1st and 2nd electrode separated over a large space | interval.   It is a front fragmentary sectional view which shows the structure at the time of applying the spot welding gun concerning this invention to C type.   It is front sectional drawing which shows the drive mechanism of the conventional spot welding gun in a pressurization state.   It is front sectional drawing which shows the drive mechanism of the conventional spot welding gun in a small open state.   It is front sectional drawing which shows the drive mechanism of the conventional spot welding gun in a large open state.

Explanation of symbols

10 spot welding gun 12 support shaft 14 first arm 16 second arm 18 first electrode 20 second electrode 22 drive mechanism 24 first grip end 26 second grip end 28 cylinder 30 piston 30A piston main body 30B Piston rod 30C Expansion portion 32 Restriction mechanism 34A First cylinder chamber 34B Second cylinder chamber 36 Connection mechanism 38 First air port 40 Second air port 42 Restriction member 42A Attachment portion 42B Restriction piece 44 Hole 44A Large Diameter hole 44B Restriction hole 46 Bolt 48 Operation lever 50 Biasing spring 52 Guide pin 54 Slot 60 C type gun (conventional technology)
70 Drive mechanism 72 First cylinder 74 Second cylinder 76 Piston 78 Piston rod 80 First air port 82 First cylinder chamber 84 Second air port 86 Second cylinder chamber 88 Third air port 90 First 3 cylinder chambers

Claims (10)

A first arm and a second arm that are pivotally supported around a common spindle;
A first electrode attached to one end of the first arm;
A second electrode attached to one end of the second arm and set to be in contact with the first electrode;
A driving means interposed between the first arm and the second arm, for driving to open and close between the first and second electrodes;
The driving means includes
Spot welding characterized in that it is constructed between the other end portion of the first arm and a portion between the support shaft of the second arm and the one end portion of the second arm. gun. The drive means is rotatably connected to the second arm by a connection mechanism,
The coupling mechanism is
A guide pin rotatably attached to the tip of the drive mechanism;
An elongated hole formed in a portion between the support shaft of the second arm and the one end of the second arm;
The spot welding gun according to claim 1, wherein the guide pin is slidably inserted into the elongated hole.   The elongated hole extends in a direction crossing the advancing / retreating direction of the drive mechanism, and the second arm rotates as the guide pin moves through the elongated hole according to the advance / retreat of the drive mechanism. The spot welding gun according to claim 2, wherein the spot welding gun moves.   The driving means includes a cylinder attached to the first arm, and a piston slidably housed in the cylinder and having a tip attached to the second arm via the coupling mechanism. The spot welding gun according to claim 2 or 3, wherein the spot welding gun is provided. The driving means includes a regulating means for regulating a moving stroke of the piston when the electrodes are separated from each other, between the cylinder and the piston in the cylinder.
Between the first and second electrodes, a small interval is defined in a state where the movement stroke of the piston is regulated by the regulation means, and a movement stroke of the piston by the regulation means is not regulated, The spot welding gun according to claim 4, wherein a large interval is defined.   6. The spot welding gun according to claim 4 or 5, wherein the driving means includes an operating portion for operating the restricting means outside the cylinder.   The restricting means is attached to the cylinder so as to be rotatable around the central axis of the cylinder and immovable along the central axis, and has a flat cross section and the piston. When the restriction member is opened to the end surface on the side where the restriction member is disposed, the cross-sectional shape is formed so as to extend along the central axis, and the restriction member is at a predetermined first angular position. Allows the insertion of the restricting member, and when the restricting member is at a second angular position different from the first angular position, a hole formed to prevent the restricting member from being inserted; When the restricting member is at the first angular position, the movement stroke of the piston is not restricted, and when the restricting member is at a second angular position different from the first angular position, The movement stroke is restricted Spot welding gun according to claim 5, characterized in Rukoto.   The spot welding according to claim 7, wherein the regulating member has an end portion that penetrates the cylinder and protrudes to the outside, and the protruding end portion is rotatable by an operator. gun.   A lever extending along a direction substantially orthogonal to the restricting member is integrally attached to the protruding end of the restricting member, and the operator rotates the lever so that the movement stroke of the piston is reduced. The spot welding gun according to claim 8, wherein switching is performed between regulation and deregulation to change the degree of opening between the first and second electrodes.   The restricting member is urged to rotate from the first angular position toward the second angular position by an urging member, and is elastically held at the second angular position. The spot welding gun according to claim 9, which is characterized by:

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