Wire buffer device, buffer amount controlling system, and welding system

Abstract

To provide a wire buffer device which accurately detects a buffer amount, while adequately securing a buffer amount with a compact constitution.SOLUTION: A wire buffer device for controlling a sagging amount of a welding wire between feeding devices includes a base, the base comprising: a wire inlet part; a wire outlet part; a tube into which the welding wire is inserted and whose annular part is curved; a rod; a slider sliding in a radial direction of the annular part; a crank shaft disposed at a center position of the annular part; and a detection sensor. The rod is connected to a slide mechanism which slides in the radial direction of the annular part so that the crank shaft rotates according to slide movement of the slider, and connected to the crank shaft. The slide mechanism has a tube insertion part where the tube is inserted. The slide mechanism slides in the radial direction of the annular part following the movement of the tube in the radial direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a wire buffer device, a buffer amount control system, and a welding system. [Background technology]

[0002] Conventionally, in a welding device using a welding wire, a configuration is known in which a buffer device is provided between a push feeder arranged on the wire pack side for feeding only in the forward direction and a pull feeder arranged on the welding torch side for feeding in the forward and reverse directions to smoothly feed the welding wire. In such a welding device, if the feed directions of the push feeder and the pull feeder are different, a large load is applied to the welding wire in the feed path when a feeding failure occurs, and there is a risk that feeding control will not be performed appropriately. For this reason, a welding system has been disclosed in which the amount of load applied to the welding wire detected by the buffer device is fed back to the push feeder or the pull feeder.

[0003] Patent document 1 describes a wire accommodating device that has a housing body including an entrance portion through which the wire is inserted, an exit portion, a storage area that accommodates the wire in a curved ring shape, and a guide portion accommodated in the storage area, and one of a first end portion closer to the entrance portion and a second end portion closer to the exit portion is fixed to the housing body, and the other is supported so as to be slidable along the axial direction. Similarly, Patent Document 2 describes a wire buffer forming mechanism comprising a tubular wire guide having a wire introduction end and a wire delivery end, and a support base supporting the wire guide, wherein the wire introduction end is fixed to the support base, the wire delivery end is supported so as to be movable relative to the support base in the axial direction, and the wire guide forms a loop so that the wire introduction end and the wire delivery end face in opposite directions.

[0004] Patent Document 3 describes a wire buffer forming device having a housing through which a wire passes while forming an L-shaped arch between an inlet portion and an outlet portion. Patent Document 4 describes a wire storage device in which a wire is stored in an S-shaped curved state in a storage body through which the wire is inserted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-217689 A [Patent Document 2] JP 2010-52021 A [Patent Document 3] JP 2017-136613 A [Patent Document 4] JP 2015-199091 A Summary of the Invention [Problem to be solved by the invention]

[0006] The disclosures in Patent Documents 1 and 2 aim to ensure a sufficient wire storage capacity (hereinafter also referred to as buffer volume or slack volume) of the wire buffer device by making the wire feed path circular. However, since the wire curved into a circular shape must be stored in the guide section and either the inlet or outlet section must be moved significantly to absorb the wire load, the device as a whole becomes larger. In addition, differences in wire diameter and hardness have a large effect, and depending on the type of wire, the device as a whole becomes even larger.

[0007] The disclosures in Patent Documents 3 and 4 aim to make the overall size of the device compact. However, because the wires are bent and held in an L-shape or S-shape in both documents, there are problems in that the buffer volume cannot be sufficiently secured and the detection accuracy of the buffer volume tends to be low.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a wire buffer device, a buffer amount control system, and a welding system that are compact in configuration and can accurately detect the buffer amount while ensuring a sufficient buffer amount. [Means for solving the problem]

[0009] The above object of the present invention can be achieved by the following configuration. (1) A wire buffer device disposed between a first feeding device and a second feeding device for controlling a slack amount of a welding wire between the feeding devices, comprising: The wire buffer device is a wire inlet through which the welding wire is fed from the first feeding device; a wire outlet portion that delivers the welding wire toward the second feeder; a tube through which the welding wire is inserted, the tube having a curved annular portion formed by crossing between the wire inlet portion and the wire outlet portion; a base having an accommodation area for accommodating the wire inlet portion, the wire outlet portion, and the annular portion of the tube; a sliding mechanism including: a tube insertion portion disposed in the accommodation area, the tube being inserted therethrough and moving in a radial direction as the diameter of the annular portion expands or contracts; and a slider moving together with the tube insertion portion; a crank mechanism including a crankshaft journaled at a center position of the accommodation area and a rod having both longitudinal ends connected to the slider and the crankshaft, respectively, for rotating the crankshaft in association with movement of the slider; a detection sensor for detecting a rotation angle of the crankshaft; Equipped with Wire buffer device. (2) The wire buffer device according to (1), a push feeder serving as the first feeding device that feeds the welding wire to the wire buffer device; a pull feeder serving as the second feeding device to which the welding wire is fed from the wire buffer device; A control unit, Buffer volume control system. (3) A welding robot equipped with the wire buffer device according to (1), A welding power source. Welding system. Effect of the Invention

[0010] According to the present invention, it is possible to accurately detect the buffer amount while ensuring a sufficient buffer amount with a compact configuration. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a welding system in which a wire buffer device according to an embodiment is used. [Diagram 2] FIG. 2 is a schematic side view of a welding robot in which the wire buffer device according to this embodiment is used. [Diagram 3] FIG. 3 is a perspective view of the wire buffer device. [Figure 4] FIG. 4 is a front view of the wire buffer device. [Diagram 5] FIG. 5 is a cross-sectional view taken along line AA of FIG. [Figure 6] FIG. 6 is a cross-sectional view of a main part of the sliding portion. [Figure 7] FIG. 7 is a front view showing the wire buffer device in an expanded state; [Figure 8] FIG. 8 is a front view showing the wire buffer device in a contracted state. [Figure 9] FIG. 9 is a block diagram of the control unit. [Figure 10] FIG. 10 is a cross-sectional view of a main part of a sliding portion of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The configuration of a wire buffer device to which the present invention is applied will be described below with reference to the accompanying drawings. Note that each drawing is created for the purpose of explaining the present invention, and the embodiment of the present invention is not limited to the contents of the drawings.

[0013] First, in order to grasp the overall picture of a wire buffer device to which the present invention is applied, a welding system in which the wire buffer device is used will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram of a welding system in which a wire buffer device according to an embodiment is used, and Figure 2 is a schematic side view of a welding robot in which a wire buffer device according to this embodiment is used.

[0014] (Welding Systems) The welding system 100 includes a welding robot 110, a robot control device 120, a welding power source 130, a servo amplifier 140, a pull feeder 150, a push feeder 160, and a wire buffer device 10. This configuration may be seen in FIG.

[0015] The welding robot 110 includes a welding torch 111 as an end effector. The welding torch 111 has an energization mechanism for energizing the welding wire W, that is, a welding tip. When electricity is applied from the welding tip, the welding wire W generates an arc from its tip, and the heat is used to weld the workpiece 200 that is the object of welding. The welding tip is also generally referred to as a contact tip.

[0016] The welding torch 111 includes a nozzle that serves as a mechanism for ejecting a shielding gas. The shielding gas is not particularly limited, but specifically, it is preferable that the shielding gas contains at least one gas among carbon dioxide gas, nitrogen gas, hydrogen gas, and oxygen gas, which have a high potential gradient. From the viewpoint of versatility, in the case of a mixed gas with argon gas, a system containing at least 10% by volume of carbon dioxide gas or more is more preferable, a system containing 90% by volume of carbon dioxide gas or more is even more preferable, and it is even more preferable to use carbon dioxide gas alone. The shielding gas is supplied from a shielding gas supply device (not shown).

[0017] Robot controller 120 mainly controls the operation of welding robot 110. Robot controller 120 has control information such as the operation pattern, welding start position, welding end position, welding conditions, weaving operation, etc. of welding robot 110 input in advance by a teaching pendant (not shown) or the like. Welding robot 110 and welding power source 130 operate based on the control information input to this robot controller 120. Note that robot controller 120 may be configured to be provided integrally with welding power source 130.

[0018] Welding power source 130 is connected to welding robot 110 via a positive power cable (not shown) so as to be able to energize a welding wire, which is a consumable electrode, and is also connected to workpiece 200 via a power cable (not shown). Workpiece 200 is also referred to as a base material.

[0019] The push feeder 160 is connected to the welding power source 130 via a signal line. In this embodiment, the push feeder 160 has a push motor (not shown) that is controlled by a feed control unit 131 provided in the welding power source 130.

[0020] The pull feeder 150 is provided near the welding torch 111, and is connected to the servo amplifier 140. The pull feeder 150 has a servo motor (not shown) that is controlled by the feed control unit 131 via the servo amplifier 140. In this embodiment, the welding torch 111 is configured to be independent from the pull feeder 150, but the welding torch 111 may be configured to have the pull feeder 150 integrally therewith.

[0021] The wire buffer device 10 is disposed between the pull feeder 150 and the push feeder 160. In this embodiment, the wire buffer device 10 is attached and fixed to the welding robot 110. Since the push feeder 160 feeds the wire only in the forward direction and the pull feeder 150 feeds the wire in both the forward and reverse directions, the push feeder 160 and the pull feeder 150 may have different feeding directions. Therefore, the wire buffer device 10 slackens the welding wire W and detects the amount of slack in the welding wire W and feeds it back to the pull feeder 150 or the push feeder 160, thereby enabling appropriate feeding control even in such a feeding situation. Hereinafter, the amount of slack in the welding wire W that the wire buffer device 10 can absorb is also referred to as the buffer amount. That is, the feed control unit 131 can execute feed control for controlling the pull feeder 150 and the push feeder 160 based on the buffer amount of the welding wire W detected by the wire buffer device 10.

[0022] (Wire buffer device) Next, a specific configuration of the wire buffer device 10 according to this embodiment will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a perspective view of the wire buffer device, Fig. 4 is a front view of the wire buffer device, Fig. 5 is a cross-sectional view taken along line AA in Fig. 4, and Fig. 6 is a cross-sectional view of the main parts of the sliding portion.

[0023] The wire buffer device 10 includes a base 21 that constitutes the storage section 20, a wire inlet section 22, a wire outlet section 23, a guide section 24, a wire tube 25, a protective sleeve 26, a sliding section 30, a crank section 41, and a detection sensor 44. The base 21 forms the accommodation portion 20 in which the wire tube 25 through which the welding wire W is inserted is accommodated. The wire tube 25 accommodated in the accommodation portion 20 has one end supported by the wire inlet portion 22 and the other end supported by the wire outlet portion 23, and has an annular portion 25a curved into a circular shape. The sliding portion 30 is attached to the annular portion 25a of the wire tube 25 and moves along the radial direction of the annular portion 25a.

[0024] The base 21 has a disk-shaped substrate portion 21a and an annular edge portion 21b formed by raising the substrate portion 21a along the outer edge side of the substrate portion 21a, thereby forming the housing portion 20 in which the wire tube 25 curved in an annular shape is housed. The accommodating section 20 has a accommodating area 20b that accommodates the wire tube 25 while guiding it to bend into a ring shape, an introduction area 20a that guides the wire tube 25 from a wire inlet section 22 provided at one upper end side of the accommodating section 20 to the accommodating area 20b, and an outlet area 20c that guides the wire tube 25 from the accommodating area 20b to a wire outlet section 23 provided at the other upper end side of the accommodating section 20.

[0025] A recess 27 in which the sliding portion 30 is disposed is formed on the outer edge side of the accommodation area 20b of the accommodation portion 20. In this embodiment, three recesses 27 and three sliding portions 30 are disposed along the outer edge of the substrate portion 21a. Specifically, a first recess 27A in which the first sliding portion 30A is disposed, a second recess 27B in which the second sliding portion 30B is disposed, and a third recess 27C in which the third sliding portion 30C is disposed are provided at equal intervals on the outer edge of the accommodation area 20b.

[0026] A guide portion 24 for guiding the annular portion 25a of the wire tube 25 is formed on the outer edge side of the receiving region 20b of the receiving portion 20. The guide portion 24 is disposed along the inside of the edge portion 21b, is provided in an arc shape concentric with the edge portion 21b, and is a protruding piece that protrudes from the base portion 21a in the same direction as the edge portion 21b. As a result, a tube support portion that supports the wire tube 25 is formed between the guide portion 24 and the edge portion 21b.

[0027] A lid portion 28 is provided at the upper ends of the introduction area 20a and the delivery area 20c of the storage portion 20 via a hinge for opening and closing the storage portion 20. This configuration may be seen in FIG. Correspondingly, a pair of fixing magnets 29, 29 for fixing the closed lid portion 28 in place for easy removal are provided in the accommodation area 20b. Note that, within the accommodation area 20b, inside the guide portion 24, an auxiliary switch 15 for performing a micro-feed operation of the welding wire W by the push feeder 160 is disposed. This configuration may be seen in Figs. 3 and 4.

[0028] The wire inlet portion 22 is disposed at one axial end of the upper end of the housing portion 20. One end side of the wire tube 25 is attached and fixed to the wire inlet portion 22 so as not to slide in the axial direction. The wire outlet portion 23 is disposed at the other axial end of the upper end of the housing portion 20. The other end side of the wire tube 25 is supported by the wire outlet portion 23 in a state where sliding in the axial direction is permitted. The wire inlet portion 22 and the wire outlet portion 23 are disposed on substantially the same axis. This configuration can be seen in FIGS.

[0029] The wire tube 25 is a tube through which the welding wire W is inserted, and is housed in the housing portion 20. Both ends of the wire tube 25 are supported by the wire inlet portion 22 and the wire outlet portion 23, and intersect between the introduction region 20a and the delivery region 20c. As a result, the wire tube 25 forms an annular portion 25a that is curved annularly along the guide portion 24 within the housing region 20b of the housing portion 20. This configuration can be seen in Figures 3 and 4. In addition, the end of the wire tube 25 on the wire outlet portion 23 side slides in the axial direction, so that the diameter of the annular portion 25a of the wire tube 25 varies. The diameter of the annular portion 25a is also referred to as a loop diameter. In this way, the wire buffer device 10 functions as a buffer that absorbs slack in the welding wire W. This configuration may be seen in Figs. 7 and 8.

[0030] The protective sleeves 26 are a plurality of cylindrical members curved in an arc so as to be disposed between the edge portion 21b and the guide portion 24, and the wire tube 25 is inserted through the protective sleeves 26. The protective sleeves 26 are disposed intermittently so as to avoid the sliding portion 30. Specifically, the protective sleeve 26 includes a first protective sleeve 26A extending from near the wire exit portion 23 to the first sliding portion 30A, a second protective sleeve 26B extending from the first sliding portion 30A to the second sliding portion 30B, a third protective sleeve 26C extending from the second sliding portion 30B to the third sliding portion 30C, a fourth protective sleeve 26D extending from the third sliding portion 30C to near the wire entrance portion 22, and a fifth protective sleeve 26E covering the area within the accommodating portion 20 from the portion where the annular wire tubes 25 intersect to the wire exit portion 23. The inner diameter of the protective sleeve 26 is larger than the outer diameter of the wire tube 25, and defines the range within which the diameter of the annular portion 25a of the wire tube 25 can expand and contract.

[0031] According to this configuration, the wire tube 25, whose loop diameter varies, is in sliding contact with the inner peripheral surface of the protective sleeve 26, which has little sliding resistance. This prevents the wire tube 25 from directly rubbing against the edge portion 21b or the guide portion 24, which would cause early deterioration.

[0032] Furthermore, by providing a fifth protective sleeve 26E at the wire outlet portion 23, the welding wire W exposed from the wire tube 25 in the feed-out region 20c can be protected as the loop diameter of the wire tube 25 increases. More specifically, one end side of wire tube 25 slides in the axial direction at wire outlet portion 23, so that when loosened welding wire W is absorbed into wire buffer device 10 from wire outlet portion 23 during welding operation, the end of wire tube 25 may be pushed into housing portion 20, causing welding wire W to become exposed inside housing portion 20. Such exposure of welding wire W can be prevented by fifth protective sleeve 26E.

[0033] The sliding portion 30 and the crank portion 41 will be described with reference to FIGS. The sliding parts 30 are provided in a plurality of recesses 27 arranged at equal intervals along the outer edge of the substrate part 21a. In this embodiment, the sliding parts 30 have a first sliding part 30A arranged in the first recess 27A, a second sliding part 30B arranged in the second recess 27B, and a third sliding part 30C arranged in the third recess 27C. This configuration may be seen in Figs. 3 and 4. Each sliding portion 30 includes a slider 31 , a guide shaft 32 , a support plate 33 , a tube insertion portion 34 , and a guide groove 35 . The crank portion 41 has a crankshaft 42 and a rod 43. The crankshaft 42 is a support member that is journaled at the center of the accommodation area 20b. The rod 43 has both longitudinal ends connected to the slider 31 and the crankshaft 42, respectively, and rotates the crankshaft 42 in association with the movement of the slider 31 provided on each sliding portion 30.

[0034] The guide shafts 32 are rod-shaped members extending radially of the annular portion 25a of the wire tube 25, and are provided so as to bridge the open ends of the recesses 27. The axial ends of each guide shaft 32 are fixed to the recesses 27 by fixing bolts fastened along the axial direction of the guide shafts 32. This configuration may be seen in Figs. 5 and 6.

[0035] The slider 31 is provided so as to slide along the guide shaft 32 in the radial direction of the annular portion 25a. The slider 31 has a slider body 31a to which one end of the rod 43 and the support plate 33 are attached, and a guide tube 31b fixed to the slider body 31a and inserted onto the guide shaft 32. That is, the one end of the rod 43 and the support plate 33 slide along the guide shaft 32 together with the slider 31.

[0036] The tube insertion portion 34 is formed between a ball bearing 36 journaled on a first support shaft 38 fixed to the support plate 33, and a roller 37 journaled on a second support shaft 39 fixed to the support plate 33. The tube insertion portion 34 configures a roller mechanism in which the wire tube 25 is inserted slidably in the longitudinal direction thereof, by arranging the ball bearing 36 and the roller 37 side by side along the extension direction of the guide shaft 32. At this time, the outer ring of the ball bearing 36 is formed with an abutment surface 36a that is recessed in a semicircular shape along the cross-sectional shape of the wire tube 25. As a result, the abutment surface 36a of the tube insertion portion 34 fits tightly into half of the outer circumferential surface of the cylindrical wire tube 25. This configuration may be seen in FIG. 6.

[0037] A guide roller 40 is supported on one end of a first support shaft 38 that constitutes the tube insertion portion 34. The guide roller 40 is disposed in a guide groove 35 formed in the recess 27, and rolls along the guide groove 35. This guide groove 35 is formed along the extending direction of the guide shaft 32. Therefore, the tube insertion portion 34 moves along the guide groove 35 formed along the surface direction of the base plate portion 21a. This configuration may be seen in Figs. 5 to 7. That is, the above-mentioned sliding portion 30 allows the wire tube 25 inserted into the tube insertion portion 34 to slide in the axial direction by the roller mechanism, and allows the slider 31 to slide smoothly and accurately along the guide shaft 32 even when an external force is applied in a direction intersecting the sliding direction of the slider 31. Note that the guide roller 40 may be replaced with a pin as described later.

[0038] The rod 43 is a member having one end fixed to the crankshaft 42 and the other end fixed to the slider 31 , and connects the crankshaft 42 and the sliding portion 30 . The rod 43 is provided in each sliding part 30. That is, in this embodiment, the slider 31 and the crankshaft 42 of the first sliding part 30A are connected by a first rod 43A, the slider 31 and the crankshaft 42 of the second sliding part 30B are connected by a second rod 43B, and the slider 31 and the crankshaft 42 of the third sliding part 30C are connected by a third rod 43C.

[0039] The crankshaft 42 is a support member journaled at the center of the accommodation area 20b, and rotates with the movement of the sliders 31 provided on each sliding portion 30. The crankshaft 42 has a shaft portion 42a and a disk-shaped flange portion 42b extending radially from the shaft portion 42a. The shaft portion 42a is a cylindrical shaft member provided on the center side of the housing portion 20 so as to rotate integrally with an inner ring of a bearing 49 fixed in a through hole formed in the base plate portion 21a. The shaft portion 42a is attached to the flange portion 42b by using a fixing bolt 48 provided on the same axis so as to rotate integrally with the flange portion 42b. This configuration may be seen in FIG. 5. The flange portion 42b is provided with a first connecting portion 46A to which the first rod 43A is connected, a second connecting portion 46B to which the second rod 43B is connected, and a third connecting portion 46C to which the third rod 43C is connected, at equal intervals along the outer edge side. In this case, the positions of the connecting portions 46A, 46B, and 46C of the flange portion 42b are such that the rods 43 are inclined at the same angle with respect to the axis of each of the sliding portions 30A, 30B, and 30C from a line connecting the sliding portions 30A, 30B, and 30C connected to the other side of the rod 43 and the shaft portion 42a of the crankshaft 42 in a front view. This configuration may be seen in FIGS. 7 and 8. In this embodiment, each rod 43 is inclined counterclockwise around each sliding portion 30A, 30B, 30C as an axis, but the inclination direction may be reversed.

[0040] According to the above, the three sliding parts 30A, 30B, and 30C provided at equal intervals along the outer edge of the accommodation area 20b are connected via the crank part 41 that functions as a linking mechanism. Therefore, the operations of the sliding parts 30A, 30B, and 30C associated with the change in diameter of the annular part 25a of the wire tube 25 are all synchronized. Therefore, the loop diameter of the wire tube 25 can be smoothly enlarged and reduced while maintaining a shape close to a perfect circle without destroying or distorting the shape of the annular part 25a, and a local change in the curvature of the welding wire W in the wire buffer device 10 can be prevented, so that a compact configuration of the wire buffer device 10 can be realized.

[0041] In addition, since the connecting portions 46A, 46B, 46C that connect the crankshaft 42 and the rod 43 are arranged at equal intervals along the outer edge of the crankshaft 42, when the wire buffer device 10 is subjected to inertia, the inertias received by each sliding portion 30A, 30B, 30C cancel each other out, and the resultant force becomes zero. That is, even if the wire buffer device 10 mounted on the welding robot 110 is subjected to inertia during welding work, the crankshaft 42 is not affected by the inertia and does not rotate by itself.

[0042] The detection sensor 44 is a potentiometer that is fixedly attached to a sensor support plate 45 and disposed coaxially with the shaft portion 42 a of the crankshaft 42 , and detects the rotational / pivot position of the crankshaft 42 . The sensor support plate 45 is attached and fixed to the base plate portion 21a via a plurality of fixing bolts 47 so as to sandwich the crankshaft 42 in the axial direction of the shaft portion 42a. In this embodiment, the sensor support plate 45 is formed in a triangular shape, and is fixed to the base plate portion 21a side by three fixing bolts 47, 47, 47 provided along the outer edge. This configuration may be seen in Figs. 3 to 5.

[0043] (Action and Effects) The operation and effect of the wire buffer device 10 will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a front view showing the wire buffer device in an expanded state, and Fig. 8 is a front view showing the wire buffer device in a contracted state.

[0044] When the welding wire W becomes loose during welding operation, the wire buffer device 10 absorbs the looseness of the welding wire W, and the loop diameter of the wire tube 25 in the housing portion 20 increases. Accordingly, the crankshaft 42 rotates clockwise in a front view via the sliders 31 of the sliding portions 30A, 30B, and 30C and the rods 43A, 43B, and 43C. As a result, the wire tube 25 enters an expanded diameter state in which the loop diameter increases while maintaining the shape of the annular portion 25a. As a result, the amount of the welding wire W accommodated in the housing portion 20 increases. In other words, the amount of the welding wire W buffered in the housing portion 20 increases. This configuration may be seen in FIG. 7.

[0045] On the other hand, in the wire buffer device 10, when the slack of the welding wire W is eliminated, the loop diameter of the wire tube 25 in the storage section 20 becomes smaller. Accordingly, the crankshaft 42 rotates counterclockwise in a front view via the sliders 31 of the sliding sections 30A, 30B, and 30C and the rods 43A, 43B, and 43C. As a result, the wire tube 25 becomes in a diameter-reduced state in which the loop diameter is reduced while maintaining the shape of the annular section 25a. As a result, the wire tube 25 becomes in a state in which it can absorb the slack of the welding wire W in the storage section 20 again. This configuration may be seen in FIG. 8.

[0046] In other words, the wire buffer device 10 has a compact configuration that fits within the storage section 20 and functions as a buffer that absorbs slack in the welding wire W during welding operations by expanding and contracting the loop diameter of the wire tube 25 to absorb the wire length of the maximum stroke amount of the slider 31 × 2π. Furthermore, the wire buffer device 10 can constantly detect the buffer amount of the welding wire W that can be absorbed in the accommodation part 20 by detecting the rotational position of the crankshaft 42 with the detection sensor 44. By making the offset distance from the axial center of the crankshaft 42 to the connecting part 46 as small as possible and setting the angle between the line connecting the axial center of the crankshaft 42 to the connecting part 46 and the axis of the rod 43 to about 90°, the rotational angle of the detection sensor 44 can be moved significantly relative to the displacement of the slider 31 in the loop radial direction, thereby providing excellent detection accuracy.

[0047] (Feed control section) Next, the feed control section will be described with reference to Fig. 9. Fig. 9 is a block diagram of the control section. The input side of the feed control unit 131 is connected to the welding power source 130, the auxiliary switch 15, and the detection sensor 44. The output side of the feed control unit 131 is connected to the push feeder 160 and the pull feeder 150.

[0048] The feed control unit 131 is configured to be able to perform feed control in which the feed amount speed of the welding wire W is adjusted by controlling the drive of the servo motor on the pull feeder 150 side and / or the push motor of the push feeder 160 based on the buffer amount of the wire buffer device 10 detected by the detection sensor 44, thereby avoiding compression and tension of the welding wire W due to accumulation of feed speed errors of the push feeder 160 and the pull feeder 150, and feedback-controlling the buffer amount of the wire buffer device 10 so that an appropriate position (specifically, near the middle of the stroke of the slider 31) is targeted. According to the feed control, during welding operation, the welding wire W can be maintained in a buffered state with some slackness in the wire buffer device 10. That is, even if the feed amount of the push feeder 160 and the feed direction and feed amount of the pull feeder 150 differ from each other, it is possible to prevent an excessive load from being applied to the welding wire W, and to maintain smooth and stable feed of the welding wire W toward the welding torch 111.

[0049] Specifically, even if the forward feeding by the push feeder 160 and the reverse feeding by the pull feeder 150 overlap and the welding wire W is compressed between the push feeder 160 and the pull feeder 150, the buffer of the wire buffer device 10 can prevent the welding wire W from being subjected to an excessive load and buckling. Similarly, even if the amount of welding wire W fed by the pull feeder 150 increases, the buffer of the wire buffer device 10 can prevent the welding wire W from being excessively pulled and subjected to a load.

[0050] Furthermore, the feed control unit 131 is configured to be able to execute an assembly auxiliary control for driving the push motor of the push feeder 160 in the forward direction when a pressing operation of the auxiliary switch 15 in the wire buffer device 10 is detected. According to the assembly auxiliary control, the welding wire W can be fed out simply by pressing the auxiliary switch 15. Therefore, when performing the assembly work of inserting the welding wire W into the wire tube 25, the welding wire W can be fed from the push feeder 160 to the tip of the torch without getting caught anywhere in the feeding path, making it easier to assemble the wire buffer device 10.

[0051] In addition, the feed control unit 131 may be configured to drive the push motor while the auxiliary switch 15 is being pressed, or may be configured to feed the welding wire W only a preset small feed width when pressing of the auxiliary switch 15 is detected. Furthermore, since the auxiliary switch 15 is installed on the substrate portion 21a constituting the housing portion 20, it can be operated smoothly and easily during the installation work of the wire buffer device 10.

[0052] Second embodiment The configuration of the sliding portion 50 of the second embodiment will be described with reference to FIG. The sliding portion 50 includes a slider 31 , a guide shaft 32 , a support 51 , a tube insertion portion 51 a , a guide pin 52 , and a guide groove 53 . The sliding portions 50 are provided in a plurality of recesses 27 arranged at equal intervals along the outer edge of the base portion 21a.

[0053] The support body 51 is fixed to the slider 31 side and extends toward the recessed surface side of the recess 27 . The support 51 is provided with a tube insertion portion 51 a and a guide pin 52 . The tube insertion portion 51a is formed in the middle of the extension direction and is an insertion hole through which the annular portion 25a of the wire tube 25 is inserted. The guide pin 52 is fixed to an end of the support 51 and slides along the guide groove 53 . The guide groove 53 is an elongated hole that is recessed in the recess 27 and through which the guide pin 52 slides, and is formed along the extending direction of the guide shaft 32 .

[0054] The sliding portion 50 having this configuration can guide the sliding direction of the slider 31 along the radial direction of the annular portion 25a with a simpler and less expensive configuration.

[0055] The present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known technologies, and these are included in the scope of protection sought.

[0056] As described above, the present specification discloses the following: (1) A wire buffer device disposed between a first feeding device and a second feeding device for controlling a slack amount of a welding wire between the feeding devices, comprising: The wire buffer device is a wire inlet through which the welding wire is fed from the first feeding device; a wire outlet portion that delivers the welding wire toward the second feeder; a tube through which the welding wire is inserted, the tube having a curved annular portion formed by crossing between the wire inlet portion and the wire outlet portion; a base having an accommodation area for accommodating the wire inlet portion, the wire outlet portion, and the annular portion of the tube; a sliding mechanism including: a tube insertion portion disposed in the accommodation area, the tube being inserted therethrough and moving in a radial direction as the diameter of the annular portion expands or contracts; and a slider moving together with the tube insertion portion; a crank mechanism including a crankshaft journaled at a center position of the accommodation area and a rod having both longitudinal ends connected to the slider and the crankshaft, respectively, for rotating the crankshaft in association with movement of the slider; a detection sensor for detecting a rotation angle of the crankshaft; Equipped with Wire buffer device. According to this configuration, a rod connects the slider, which slides radially around the annular portion, to the crankshaft located in the center of the storage area, and a detection sensor is provided to detect the rotational position of the crankshaft. This makes it possible to accurately detect the buffer volume while ensuring a sufficient buffer volume with a compact configuration.

[0057] (2) The sliding mechanism has a ball bearing or a pin that moves along a surface direction of the base, The ball bearing or the pin moves along a guide groove formed in the base in a radial direction of the annular portion. The wire buffer device according to (1). According to this configuration, the slider can be reliably slid along the radial direction of the annular portion, so that the diameter of the annular portion can be smoothly expanded or contracted without losing its shape.

[0058] (3) The tube is attached to either the wire inlet or the wire outlet. A wire buffer device according to (1) or (2). According to this configuration, the radial extension and contraction action of the annular portion of the wire tube into which the welding wire is inserted can be smoothly performed.

[0059] (4) The tube insertion section has a roller mechanism that clamps the tube. The wire buffer device according to any one of (1) to (3). According to this configuration, the wire tube inserted into the tube insertion portion can slide smoothly without resistance, so that the radial sliding movement of the slider accompanying the radial expansion and contraction of the annular portion also becomes smooth.

[0060] (5) At least two of the rods are provided, The connecting portions between the rod and the crankshaft are arranged at equal intervals on the outer edge side of the crankshaft. The wire buffer device according to any one of (1) to (4). According to this configuration, the sliding movements of the rods are synchronized via the crankshaft, so that the radial expansion and contraction of the annular portion can be performed without destroying the shape of the annular portion. Also, when acceleration is applied to the wire buffer device, the loads applied to the rods cancel each other out, so that even if the wire buffer device is mounted on a welding robot or the welding robot moves at high speed, the diameter of the annular portion can be prevented from fluctuating due to the influence of acceleration.

[0061] (6) providing a plurality of sleeves for guiding the tube; The sleeve has an inner diameter that allows the diameter of the annular portion to expand and contract within a predetermined range. The wire buffer device according to any one of (1) to (5). According to this configuration, when the diameter of the annular portion of the wire tube varies, it is possible to prevent the wire tube from directly rubbing against the base and being deteriorated.

[0062] (7) A wire buffer device according to any one of (1) to (6), a push feeder serving as the first feeding device that feeds the welding wire to the wire buffer device; a pull feeder serving as the second feeding device to which the welding wire is fed from the wire buffer device; A control unit, Buffer volume control system. According to this configuration, the buffer amount detected by the wire buffer device can be fed back to the first feeding device and the second feeding device, thereby making the control of the feeding of the welding wire by the first feeding device and the second feeding device more stable.

[0063] (8) A welding robot including the wire buffer device according to any one of (1) to (6), A welding power source. Welding system. According to this configuration, the buffer amount detected by the wire buffer device is fed back to the first feeding device and the second feeding device, thereby stabilizing the amount of welding wire fed to the welding torch, thereby improving welding accuracy. [Explanation of symbols]

[0064] 10 Wire buffer device 15 Auxiliary Switch 20 Storage unit 20a Introduction Area 20b Containment Area 20c sending area 21 Foundation 21a Board part (base surface) 21b Edge 22 Wire inlet 23 Wire exit 24 Guide section 25 Wire tube (tube) 25a Circular section 26 Protective sleeve (sleeve) 26A First protective sleeve 26B Second protective sleeve 26C 3rd protective sleeve 26D 4th protective sleeve 26E 5th protective sleeve 27 Recess 27A First recess 27B Second recess 27C 3rd recess 28 Lid 29 Fixing magnet 30 Sliding part (sliding mechanism) 30A First sliding part 30B Second sliding part 30C 3rd sliding part 31 Slider 32 Guide shaft 33 Support plate 34 Tube insertion part 35 Guide groove 36 Ball bearing 36a Contact surface 37 Lola 38 1st support shaft 39 2nd support shaft 41 Crank section (crank mechanism, linkage mechanism) 42 Crankshaft 42a Shaft 42b Flange part 43 Rod 43A First Rod 43B 2nd Rod 43C 3rd Rod 44 Detection sensor 45 Sensor support plate 46A 1st connection part (connection part) 46B 2nd connection part (connection part) 46C 3rd connection part (connection part) 49 Bearings 50 Sliding part 51 Support 51a Tube insertion part 52 Guide pin (pin) 53 Guide groove 100 Welding System 110 Welding Robot 111 Welding torch 120 Robot control device 130 Welding power source 131 Feeding control section 140 Servo Amplifier 150 Prufeeder (second feeding device) 160 Push feeder (first feeding device) 200 Work

Claims

1. A wire buffer device disposed between a first feeding device and a second feeding device for controlling a slack amount of a welding wire between the feeding devices, The wire buffer device is a wire inlet through which the welding wire is fed from the first feeding device; a wire outlet portion that delivers the welding wire toward the second feeder; a tube through which the welding wire is inserted, the tube having a curved annular portion formed by crossing between the wire inlet portion and the wire outlet portion; a base having an accommodation area for accommodating the wire inlet portion, the wire outlet portion, and the annular portion of the tube; a sliding mechanism including: a tube insertion portion disposed in the accommodation area, the tube being inserted therethrough and moving in a radial direction as the diameter of the annular portion expands or contracts; and a slider moving together with the tube insertion portion; a crank mechanism including a crankshaft journaled at a center position of the accommodation area and a rod having both longitudinal ends connected to the slider and the crankshaft, respectively, for rotating the crankshaft in association with movement of the slider; a detection sensor for detecting a rotation angle of the crankshaft; Equipped with Wire buffer device.

2. The sliding mechanism has a ball bearing or a pin that moves along a surface direction of the base, The ball bearing or the pin moves along a guide groove formed in the base in a radial direction of the annular portion.

2. The wire buffer device according to claim 1.

3. The tube is attached to either the wire inlet or the wire outlet.

2. The wire buffer device according to claim 1.

4. The tube insertion section has a roller mechanism that clamps the tube.

2. The wire buffer device according to claim 1.

5. At least two of the rods are provided, The connecting portions between the rod and the crankshaft are arranged at equal intervals on the outer edge side of the crankshaft.

2. The wire buffer device according to claim 1.

6. providing a plurality of sleeves for guiding the tube; The sleeve has an inner diameter that allows the diameter of the annular portion to expand and contract within a predetermined range.

2. The wire buffer device according to claim 1.

7. A wire buffer device according to any one of claims 1 to 6, a push feeder serving as the first feeding device that feeds the welding wire to the wire buffer device; a pull feeder serving as the second feeding device to which the welding wire is fed from the wire buffer device; A control unit, Buffer volume control system.

8. A welding robot including the wire buffer device according to any one of claims 1 to 6; A welding power source. Welding system.

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