Wire buffer device, buffer volume control system, and welding system
The wire buffer device with a curved annular portion and sliding mechanism addresses the challenge of compact size and accurate detection, ensuring stable welding wire feeding by expanding and contracting the wire tube diameter to absorb slack and prevent load imbalances.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KOBE STEEL LTD
- Filing Date
- 2023-07-18
- Publication Date
- 2026-07-29
AI Technical Summary
Existing wire buffer devices in welding systems face challenges in achieving a compact size while ensuring sufficient buffer capacity and accurate buffer amount detection, particularly due to differences in wire diameter and stiffness, leading to potential feeding failures and load imbalances.
A wire buffer device with a curved annular portion and a sliding mechanism, equipped with a crankshaft and detection sensor, allows for radial expansion and contraction of the wire tube diameter, enabling accurate buffer amount detection and stable feeding control.
The device ensures a compact configuration with sufficient buffer capacity and precise detection, stabilizing welding wire feeding by absorbing slack and preventing excessive load, thus maintaining smooth welding operations.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a wire buffer device, a buffer amount control system, and a welding system.
Background Art
[0002] Conventionally, in a welding apparatus using a welding wire, between a push feeder arranged on the wire pack side and performing feeding only in the forward rotation direction, and a pull feeder arranged on the welding torch side and performing feeding in both the forward and reverse rotation directions, a configuration in which a buffer device for smoothly supplying the welding wire is provided is known. In such a welding apparatus, when the feeding directions of the push feeder and the pull feeder are different, if a feeding failure or the like occurs, a large load may be applied to the welding wire in the feeding path, and there is a risk that the feeding control cannot be properly performed. For this reason, a welding system that feeds back the amount of load applied to the welding wire detected by the buffer device to the push feeder or the pull feeder has been disclosed.
[0003] Patent Document 1 describes a wire storage device including a housing including an inlet through which a wire is inserted, an outlet, a storage region for storing the wire in a circularly curved state, and a guide portion stored in the storage region, and in which one of a first end portion near the inlet and a second end portion near the outlet is fixed to the housing and the other is supported so as to be slidable along the axial direction. Similarly, Patent Document 2 describes a wire buffer forming mechanism including a tubular wire guide having a wire introduction end and a wire delivery end, and a support base for supporting the wire guide, in which the wire introduction end is fixed to the support base, the wire delivery end is supported so as to be relatively movable in the axial direction with respect to the support base, and the wire guide forms a loop such that the wire introduction end and the wire delivery end face in opposite directions.
[0004] Patent Document 3 describes a wire buffer forming device including a housing through which a wire passes forming an L-shaped arch between an inlet and an outlet. Patent Document 4 describes a wire housing device in which a wire, curved in an S-shape, is housed in a housing through which the wire is inserted. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Japanese Patent Publication No. 2017-217689 [Patent Document 2] Japanese Patent Publication No. 2010-52021 [Patent Document 3] Japanese Patent Publication No. 2017-136613 [Patent Document 4] Japanese Patent Publication No. 2015-199091 [Overview of the Initiative] [Problems that the invention aims to solve]
[0006] Patent Documents 1 and 2 describe a method for ensuring sufficient wire capacity (hereinafter also referred to as buffer capacity or slack capacity) in a wire buffer device by making the wire feeding path annular. However, because it is necessary to accommodate the annularly curved wire in the guide section and to make either the inlet or outlet section highly movable to absorb the wire load, the entire device becomes large. Furthermore, there is a problem in that the overall size of the device increases even further depending on the type of wire, due to the significant impact of differences in wire diameter and stiffness.
[0007] The descriptions in Patent Documents 3 and 4 aim to make the overall size of the device compact. However, since both methods involve bending the wire into an L-shape or S-shape to hold it, there is a problem in that a sufficient buffer amount cannot be secured, and the accuracy of buffer amount detection tends to be low.
[0008] The present invention has been made in view of the above circumstances, and its objective is to provide a wire buffer device, a buffer amount control system, and a welding system that can accurately detect the buffer amount while ensuring a sufficient buffer amount in a compact configuration. [Means for solving the problem]
[0009] The above objective of the present invention is achieved by the following configuration. (1) A wire buffer device positioned between a first feeding device and a second feeding device for controlling the amount of slack in the welding wire between the feeding devices, The wire buffer device is A wire inlet from which welding wire is fed from the first feeding device, A wire outlet section that feeds the welding wire toward the second feeding device, The annular portion is curved by crossing the wire inlet portion and the wire outlet portion, and the tube through which the welding wire is inserted, A base provided with a wire inlet, a wire outlet, and a housing area for housing the annular portion of the tube, A sliding mechanism comprising: a tube insertion portion arranged in the aforementioned housing area, through which the tube is inserted and which moves radially as the diameter of the annular portion expands and contracts; and a slider that moves together with the tube insertion portion; A crank mechanism comprising: a crankshaft pivotally supported at the center of the aforementioned containment area; and a rod whose longitudinal ends are connected to the slider and the crankshaft, respectively, and which rotates the crankshaft as the slider moves; A detection sensor for detecting the rotation angle of the crankshaft, Equipped with, Wire buffer device. (2) The wire buffer device described in (1), The first feeding device, a push feeder, feeds the welding wire to the wire buffer device, A pull feeder, which is a second feeding device from which the welding wire is fed from the wire buffer device, A control unit and A buffer amount control system. (3) A welding robot equipped with the wire buffer device described in (1), A welding power source, and A welding system.
Advantages of the Invention
[0010] According to the present invention, while ensuring a sufficient buffer amount with a compact configuration, the buffer amount can be accurately detected.
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. [Figure 2] FIG. 2 is a schematic side view of a welding robot in which a wire buffer device according to the present embodiment is used. [Figure 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. [Figure 5] FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4. [Figure 6] FIG. 6 is a cross-sectional view of the main part of the sliding portion. [Figure 7] FIG. 7 is a front view showing the wire buffer device in an extended state, [Figure 8] FIG. 8 is a front view showing the wire buffer device in a reduced state. [Figure 9] FIG. 9 is a block diagram of the control unit. [Figure 10] FIG. 10 is a cross-sectional view of the main part of the sliding portion of the second embodiment.
Modes for Carrying Out the Invention
[0012] The configuration of a wire buffer device to which the present invention is applied will be described below with reference to the attached drawings. Note that the figures are created for the purpose of explaining the present invention, and the embodiments of the present invention are not limited to those shown.
[0013] First, in order to understand the overall picture of the wire buffer device to which the present invention is applied, a welding system using the wire buffer device will be described based on Figures 1 and 2. Figure 1 is a schematic diagram of a welding system using the wire buffer device according to this embodiment, and Figure 2 is a schematic side view of a welding robot using the wire buffer device according to this embodiment.
[0014] (Welding system) The welding system 100 includes a welding robot 110, a robot control device 120, a welding power supply 130, a servo amplifier 140, a pull feeder 150, a push feeder 160, and a wire buffer device 10. This configuration can be seen in Figure 1.
[0015] The welding robot 110 is equipped with a welding torch 111 as an end effector. The welding torch 111 has a current-conducting mechanism, i.e., a welding tip, for energizing the welding wire W. The welding wire W generates an arc from its tip when current is passed through it from the welding tip, and uses the heat from this arc to weld the workpiece 200. The welding tip is also commonly referred to as a contact tip.
[0016] The welding torch 111 is equipped with a nozzle that serves as a mechanism for ejecting shielding gas. The shielding gas is not particularly limited, but it is preferable that it contains at least one gas with a high potential gradient, such as carbon dioxide, nitrogen, hydrogen, or oxygen. Furthermore, from the viewpoint of versatility, in the case of a mixed gas with argon gas, a system in which at least 10% by volume of carbon dioxide is mixed is more preferable, a system in which 90% by volume of carbon dioxide is mixed is even more preferable, and using carbon dioxide alone is even more preferable. The shielding gas is supplied from a shielding gas supply device (not shown).
[0017] The robot control device 120 primarily controls the operation of the welding robot 110. The robot control device 120 has control information such as the operation pattern of the welding robot 110, welding start position, welding end position, welding conditions, and weaving operation, which are input in advance by a teaching pendant or the like (not shown). The welding robot 110 and the welding power supply 130 operate based on the control information input to the robot control device 120. The robot control device 120 may also be configured to be integrated with the welding power supply 130.
[0018] The welding power supply 130 is connected to the welding robot 110 via a positive power cable (not shown) to energize the welding wire, which is a consumable electrode, and is connected to the workpiece 200 via a power cable (not shown). The workpiece 200 is also referred to as the base material.
[0019] The push feeder 160 is connected to the welding power supply 130 by 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 on the welding power supply 130.
[0020] The pull feeder 150 is located near the welding torch 111 and is connected to a servo amplifier 140. The pull feeder 150 has a servo motor (not shown) that is controlled by a feed control unit 131 via the servo amplifier 140. In this embodiment, the welding torch 111 is configured to be independent of the pull feeder 150, but the pull feeder 150 may also be integrated into the welding torch 111.
[0021] The wire buffer device 10 is positioned 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 feeding directions of the push feeder 160 and the pull feeder 150 may differ. Therefore, the wire buffer device 10 slackens the welding wire W and detects the amount of slack in the welding wire W, and feeds this back to the pull feeder 150 or the push feeder 160, thereby enabling proper feeding control even in such feeding conditions. Hereinafter, the amount of slack in the welding wire W that the wire buffer device 10 can absorb will also be referred to as the buffer amount. In other words, the feed control unit 131 can perform feed control that controls the pull feeder 150 and the push feeder 160 based on the buffer amount of welding wire W detected by the wire buffer device 10.
[0022] (Wire buffer device) Next, the specific configuration of the wire buffer device 10 according to this embodiment will be described based on Figures 3 to 6. Figure 3 is a perspective view of the wire buffer device, Figure 4 is a front view of the wire buffer device, Figure 5 is a cross-sectional view of AA in Figure 4, and Figure 6 is a cross-sectional view of the main part of the sliding section.
[0023] The wire buffer device 10 comprises a base 21 constituting a housing 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 a housing portion 20 through which a wire tube 25 containing a welding wire W is inserted. The wire tube 25 housed in the housing portion 20 is supported at one end by a wire inlet portion 22 and at the other end by a wire outlet portion 23, and has a circularly curved annular portion 25a. 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 disc-shaped substrate portion 21a and an annular edge portion 21b formed by raising along the outer edge of the substrate portion 21a. As a result, the base 21 forms a housing portion 20 in which the annularly curved wire tube 25 is housed. The housing section 20 includes a housing area 20b that houses the wire tube 25 while guiding it to curve in an annular shape, an introduction area 20a that guides the wire tube 25 from a wire inlet 22 provided on one upper end of the housing section 20 to the housing area 20b, and a discharge area 20c that guides the wire tube 25 from the housing area 20b to a wire outlet 23 provided on the other upper end of the housing section 20.
[0025] A recess 27 is formed on the outer edge side of the housing area 20b of the housing section 20, where the sliding portion 30 is arranged. In this embodiment, three recesses 27 and three sliding portions 30 are arranged along the outer edge of the substrate portion 21a. Specifically, a first recess 27A where the first sliding portion 30A is arranged, a second recess 27B where the second sliding portion 30B is arranged, and a third recess 27C where the third sliding portion 30C is arranged are provided at equal intervals along the outer edge of the housing area 20b.
[0026] A guide portion 24 is formed on the outer edge side of the housing area 20b of the housing portion 20 to guide the annular portion 25a of the wire tube 25. The guide portion 24 is positioned along the inside of the edge portion 21b, is provided in a concentric arc shape with respect to the edge portion 21b, and is a protruding piece that projects from the base portion 21a in the same direction as the edge portion 21b. This forms a tube support portion between the guide portion 24 and the edge portion 21b that supports the wire tube 25.
[0027] A lid 28 is provided at the upper ends of the introduction area 20a and the discharge area 20c of the storage section 20, which opens and closes the storage section 20 via a hinge. This configuration can be seen in Figure 5. In response to this, a pair of fixing magnets 29, 29 are provided within the storage area 20b to easily secure the closed lid 28. Within the storage area 20b, an auxiliary switch 15 is located inside the guide section 24 for performing minute feeding operations of the welding wire W by the push feeder 160. This configuration can be seen in Figures 3 and 4.
[0028] The wire inlet portion 22 is located at one axial end of the upper end of the housing portion 20. One end 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 located at the other axial end of the upper end of the housing portion 20. The other end of the wire tube 25 is supported at the wire outlet portion 23 in a manner that allows for axial sliding. The wire inlet 22 and the wire outlet 23 are arranged on approximately the same axis. This configuration can be seen in Figures 3 and 4.
[0029] The wire tube 25 is a tube through which the welding wire W is inserted and is housed in the housing section 20. Both ends of the wire tube 25 are supported by the wire inlet section 22 and the wire outlet section 23, and intersect between the introduction region 20a and the discharge region 20c. As a result, the wire tube 25 forms an annular section 25a that curves in an annular shape along the guide section 24 within the housing region 20b of the housing section 20. This configuration can be seen by referring to Figures 3 and 4. Furthermore, the diameter of the annular portion 25a of the wire tube 25 changes as the end of the wire tube 25 on the wire outlet portion 23 side slides axially. This diameter of the annular portion 25a is also called the loop diameter. As a result, the wire buffer device 10 functions as a buffer that absorbs the slack of the welding wire W. This configuration can be seen in Figures 7 and 8.
[0030] The protective sleeve 26 consists of multiple cylindrical members that are curved in an arc shape so as to be positioned between the edge portion 21b and the guide portion 24, through which the wire tube 25 is inserted. The protective sleeve 26 is intermittently arranged to avoid the sliding portion 30. More specifically, the protective sleeve 26 includes a first protective sleeve 26A extending from the vicinity of the wire outlet 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 the vicinity of the wire inlet 22, and a fifth protective sleeve 26E within the housing portion 20 that covers from the point where the annular wire tube 25 intersects to the wire outlet 23. Furthermore, the inner diameter of the protective sleeve 26 is larger than the outer diameter of the wire tube 25, defining the range within which the diameter of the annular portion 25a of the wire tube 25 can expand and contract.
[0031] With this configuration, the wire tube 25, whose loop diameter fluctuates, slides against the inner circumferential surface of the protective sleeve 26, which has low sliding resistance. This prevents the wire tube 25 from directly rubbing against the edge 21b or the guide portion 24, thus preventing premature deterioration.
[0032] Furthermore, the fifth protective sleeve 26E provided at the wire exit portion 23 protects the welding wire W that is exposed from the wire tube 25 within the discharge region 20c as the loop diameter of the wire tube 25 increases. To explain in more detail, since one end of the wire tube 25 slides axially at the wire outlet 23, when a slack welding wire W is absorbed into the wire buffer device 10 from the wire outlet 23 during welding, the end of the wire tube 25 may be pushed into the housing 20, causing the welding wire W to be exposed within the housing 20. Such exposure of the welding wire W can be protected by the fifth protective sleeve 26E.
[0033] The sliding portion 30 and the crank portion 41 will be described based on Figures 5 and 6. The sliding portion 30 is provided in each of the multiple recesses 27 that are arranged at equal intervals along the outer edge of the substrate portion 21a. In this embodiment, the sliding portion 30 has a first sliding portion 30A located in the first recess 27A, a second sliding portion 30B located in the second recess 27B, and a third sliding portion 30C located in the third recess 27C. This configuration can be seen by referring to Figures 3 and 4. Each sliding part 30 includes a slider 31, a guide shaft 32, a support plate 33, a tube insertion part 34, and a guide groove 35. The crank section 41 includes a crankshaft 42 and a rod 43. The crankshaft 42 is a support member pivotally supported at the center of the housing area 20b. The rod 43 has both longitudinal ends connected to the slider 31 and the crankshaft 42, respectively, and rotates the crankshaft 42 as the slider 31 provided on each sliding section 30 moves.
[0034] The guide shaft 32 is a rod-shaped member that extends radially along the annular portion 25a of the wire tube 25, and is provided to span the open end side of the recess 27. The axial end of each guide shaft 32 is fixed to the recess 27 side by fixing bolts fastened along the axial direction of the guide shaft 32. This configuration can be seen in Figures 5 and 6.
[0035] The slider 31 is provided 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 externally fitted onto the guide shaft 32. That is, one end of the rod 43 and the support plate 33 slide together with the slider 31 along the guide shaft 32.
[0036] The tube insertion section 34 is formed between a ball bearing 36 supported by a first support shaft 38 fixed to the support plate 33, and a roller 37 supported by a second support shaft 39 fixed to the support plate 33. The tube insertion section 34 constitutes a roller mechanism in which the wire tube 25 is slidably inserted in its longitudinal direction, by arranging the ball bearing 36 and the roller 37 side by side along the extending direction of the guide shaft 32. At this time, a contact surface 36a is formed on the outer ring of the ball bearing 36, recessed in a semicircular shape along the cross-sectional shape of the wire tube 25. As a result, the contact surface 36a of the tube insertion portion 34 fits tightly onto half of the outer surface of the cylindrical wire tube 25. This configuration can be seen in Figure 6.
[0037] A guide roller 40 is pivotally supported at one end of the first support shaft 38, which constitutes the tube insertion section 34. The guide roller 40 is positioned within 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 substrate portion 21a. This configuration can be seen in Figures 5 to 7. In other words, the sliding part 30 described above 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, as the wire tube 25 inserted through the tube insertion part 34 slides axially by the roller mechanism. Note that the guide roller 40 may be replaced with a pin, as will be described later.
[0038] The rod 43 is a component that has one end attached and fixed to the crankshaft 42 and the other end attached and fixed to the slider 31, and connects the crankshaft 42 and the sliding part 30. Rods 43 are provided in each sliding part 30. In this embodiment, the slider 31 of the first sliding part 30A and the crankshaft 42 are connected by a first rod 43A, the slider 31 of the second sliding part 30B and the crankshaft 42 are connected by a second rod 43B, and the slider 31 of the third sliding part 30C and the crankshaft 42 are connected by a third rod 43C.
[0039] The crankshaft 42 is a support member pivotally supported at the center of the housing area 20b, and rotates in conjunction with the movement of the sliders 31 provided on each sliding part 30. The crankshaft 42 has a shaft portion 42a and a disc-shaped flange portion 42b that extends radially around the shaft portion 42a. The shaft portion 42a is a cylindrical shaft member located on the central side of the housing portion 20, and is provided to rotate integrally with the inner ring of the bearing 49 fixed to a through hole formed in the base portion 21a. The shaft portion 42a is attached to the flange portion 42b using fixing bolts 48 provided on a concentric shaft so that they rotate integrally. Refer to Figure 5 for this configuration. 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, all at equal intervals along the outer edge. At this time, the positions of each connecting portion 46A, 46B, and 46C of the flange portion 42b are such that, in a front view, each rod 43 is inclined at the same angle around each sliding portion 30A, 30B, and 30C as its axis, relative to the line connecting each sliding portion 30A, 30B, and 30C connected to the other side of the rod 43 and the shaft portion 42a of the crankshaft 42. This configuration can be seen in Figures 7 and 8. In this embodiment, each rod 43 is inclined counterclockwise around each sliding portion 30A, 30B, and 30C as an axis, but the direction of inclination may be reversed.
[0040] As described above, the three sliding parts 30A, 30B, and 30C, which are provided at equal intervals along the outer edge of the containment area 20b, are connected via a crank part 41 that functions as a linkage mechanism. Therefore, the operation of each sliding part 30A, 30B, and 30C in response to changes in the diameter of the annular part 25a of the wire tube 25 is synchronized. As a result, the loop diameter of the wire tube 25 can be smoothly expanded and contracted while maintaining a shape close to a perfect circle without distorting or altering the shape of the annular part 25a, and localized changes in the curvature of the welding wire W within the wire buffer device 10 can be prevented, thus enabling a compact configuration for the wire buffer device 10.
[0041] Furthermore, because the connecting parts 46A, 46B, and 46C, which 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 inertia experienced by each sliding part 30A, 30B, and 30C cancels out each other, resulting in a resultant force of 0. In other words, even if the wire buffer device 10 mounted on the welding robot 110 is subjected to inertia during welding, the crankshaft 42 will not rotate on its own due to the influence of inertia.
[0042] The detection sensor 44 is a potentiometer that is mounted and fixed to the sensor support plate 45 and positioned on the same axis as the shaft portion 42a of the crankshaft 42, and detects the rotational position of the crankshaft 42. The sensor support plate 45 is attached and fixed by the base plate portion 21a so as to sandwich the crankshaft 42 in the axial direction of the shaft portion 42a via a plurality of fixing bolts 47. In this embodiment, the sensor support plate 45 is formed in a triangular shape and is fixed to the base plate portion 21a by three fixing bolts 47, 47, 47 provided along its outer edge. This configuration can be seen in Figures 3 to 5.
[0043] (Mechanism of Action and Effects) The operation and effects of the wire buffer device 10 will be explained based on Figures 7 and 8. Figure 7 is a front view showing the wire buffer device in its expanded state, and Figure 8 is a front view showing the wire buffer device in its retracted state.
[0044] When the welding wire W becomes slack during welding, the wire buffer device 10 absorbs the slack in the welding wire W, thereby increasing the loop diameter of the wire tube 25 in the housing section 20. Consequently, the crankshaft 42 rotates clockwise in a front view via the sliders 31 of each sliding section 30A, 30B, and 30C, and the rods 43A, 43B, and 43C. This causes the wire tube 25 to expand in diameter while maintaining the shape of the annular section 25a. This increases the amount of welding wire W that can be accommodated in the housing section 20. In other words, the buffer capacity of the welding wire W in the housing section 20 increases. This configuration can be seen in Figure 7.
[0045] On the other hand, when the slack in the welding wire W is eliminated, the wire buffer device 10 reduces the loop diameter of the wire tube 25 in the housing section 20. Consequently, the crankshaft 42 rotates counterclockwise in a front view via the sliders 31 of each sliding section 30A, 30B, 30C and the rods 43A, 43B, 43C. As a result, the wire tube 25 enters a reduced diameter state in which the loop diameter is reduced while maintaining the shape of the annular section 25a. This makes it possible to absorb the slack in the welding wire W again within the housing section 20. Refer to Figure 8 for this configuration.
[0046] In other words, the wire buffer device 10 has a compact configuration that fits within the housing section 20 and functions as a buffer that absorbs the slack of the welding wire W during welding work by expanding and contracting the loop diameter of the wire tube 25, thereby absorbing a wire length equal to the maximum stroke amount of the slider 31 × 2π. Furthermore, the wire buffer device 10 can constantly detect the buffer amount of welding wire W that can be absorbed by the housing 20 by detecting the rotational position of the crankshaft 42 with the detection sensor 44. By minimizing the offset distance from the axis center of the crankshaft 42 to the connecting part 46, and setting the angle between the line connecting the axis center of the crankshaft 42 to the connecting part 46 and the axis of the rod 43 to around 90°, the rotation angle of the detection sensor 44 can be moved significantly in response to the displacement of the slider 31 in the loop diameter direction, thus providing excellent detection accuracy.
[0047] (Freight Delivery Control Unit) Next, the feed control unit will be described based on Figure 9. Figure 9 is a block diagram of the control unit. The input side of the feed control unit 131 is connected to a welding power supply 130, an auxiliary switch 15, and a detection sensor 44. The output side of the feed control unit 131 is connected to a push feeder 160 and a pull feeder 150.
[0048] The feeding control unit 131 controls the driving 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 adjusting the feeding rate of the welding wire W. This prevents compression and tension of the welding wire W due to the accumulation of feeding speed errors between the push feeder 160 and the pull feeder 150, and enables feeding control that feedback controls the buffer amount of the wire buffer device 10 so that it reaches the target position (specifically, around the middle of the slider 31's stroke). According to the feed control, a buffer state can be maintained in the wire buffer device 10 during welding, allowing the welding wire W to be somewhat slack. In other words, even if the feed rate of the push feeder 160 and the feed direction and feed rate of the pull feeder 150 are different, it is possible to prevent excessive load from being placed on the welding wire W and to maintain smooth and stable feeding of the welding wire W toward the welding torch 111.
[0049] To explain in more detail, 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 prevents excessive load from being placed on the welding wire W, thus preventing 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 prevents the welding wire W from being excessively pulled and subjected to excessive load.
[0050] Furthermore, the feeding control unit 131 is configured to perform assembly auxiliary control, which involves driving the push motor of the push feeder 160 in the forward direction when a push operation of the auxiliary switch 15 in the wire buffer device 10 is detected. With the assembly assist 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 at any point in the feeding path, making the assembly work of the wire buffer device 10 easier.
[0051] Furthermore, the feed control unit 131 may be configured such that the push motor is driven while the auxiliary switch 15 is pressed, or it may be configured such that when the pressing operation of the auxiliary switch 15 is detected, the welding wire W is fed only by a preset minute feed width. Furthermore, since the auxiliary switch 15 is installed on the circuit board 21a that constitutes the housing 20, it can be operated smoothly and easily during the installation of the wire buffer device 10.
[0052] (Second Embodiment) Based on Figure 10, the configuration of the sliding part 50 of the second embodiment will be described. The sliding portion 50 includes a slider 31, a guide shaft 32, a support 51, a tube insertion portion 51a, a guide pin 52, and a guide groove 53. The sliding portion 50 is provided in each of the multiple recesses 27 that are arranged at equal intervals along the outer edge of the substrate portion 21a.
[0053] The support 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 51a and a guide pin 52. The tube insertion portion 51a is formed in the middle of the extending direction and is an insertion hole through which the annular portion 25a of the wire tube 25 is inserted. The guide pin 52 is attached and fixed to the end of the support 51 and slides along the guide groove 53. The guide groove 53 is a recessed hole in the recess 27 through which the guide pin 52 slides, and is formed along the extending direction of the guide shaft 32.
[0054] With the sliding portion 50 of this configuration, the sliding direction of the slider 31 can be guided to align with the radial direction of the annular portion 25a in a simpler and lower-cost configuration.
[0055] It should be noted that the present invention is not limited to the embodiments described above. Combining the various components of the embodiments with each other, and modifying and applying them based on the description in the specification and well-known technology, are also intended to be done by those skilled in the art and are included within the scope of protection.
[0056] As described above, the following matters are disclosed in this specification: (1) A wire buffer device positioned between a first feeding device and a second feeding device for controlling the amount of slack in the welding wire between the feeding devices, The wire buffer device is A wire inlet from which welding wire is fed from the first feeding device, A wire outlet section that feeds the welding wire toward the second feeding device, The annular portion is curved by crossing the wire inlet portion and the wire outlet portion, and the tube through which the welding wire is inserted, A base provided with a wire inlet, a wire outlet, and a housing area for housing the annular portion of the tube, A sliding mechanism comprising: a tube insertion portion arranged in the aforementioned housing area, through which the tube is inserted and which moves radially as the diameter of the annular portion expands and contracts; and a slider that moves together with the tube insertion portion; A crank mechanism comprising: a crankshaft pivotally supported at the center of the aforementioned containment area; and a rod whose longitudinal ends are connected to the slider and the crankshaft, respectively, and which rotates the crankshaft as the slider moves; A detection sensor for detecting the rotation angle of the crankshaft, Equipped with, Wire buffer device. In this configuration, a rod connects a slider that slides radially in the annular section to a crankshaft located at the center of the storage area, and a detection sensor is provided to detect the rotational position of the crankshaft. This allows for a compact configuration that ensures sufficient buffer volume while accurately detecting the buffer volume.
[0057] (2) The sliding mechanism has a ball bearing or pin that moves along the surface direction of the base, The ball bearing or pin moves along the radial direction of the annular portion along the guide groove formed in the base. (1) The wire buffer device described above. With this configuration, the slider can be reliably slid along the radial direction of the annular section, allowing the diameter of the annular section to expand and contract smoothly without distorting its shape.
[0058] (3) The tube is attached to either the wire inlet or the wire outlet. The wire buffer device described in (1) or (2). This configuration allows for smooth radial expansion and contraction of the annular portion of the wire tube into which the welding wire is inserted.
[0059] (4) The tube insertion section has a roller mechanism for gripping the tube, A wire buffer device as described in any one of (1) to (3). With this configuration, the wire tube inserted into the tube insertion section can slide smoothly without resistance, and as a result, the radial sliding movement of the slider accompanying the radial expansion and contraction of the annular section also becomes smooth.
[0060] (5) Provide at least two of the aforementioned rods, The connecting portion between the rod and the crankshaft is arranged at equal intervals on the outer edge side of the crankshaft. A wire buffer device as described in any one of (1) to (4). With this configuration, the sliding movement of each rod is synchronized via the crankshaft, allowing the radial expansion and contraction of the annular section to be performed without distorting its shape. Furthermore, when acceleration is applied to the wire buffer device, the loads on each rod cancel each other out, so even if the wire buffer device is mounted on a welding robot, and even if the welding robot moves at high speed, the diameter of the annular section will not fluctuate due to the effects of acceleration.
[0061] (6) A plurality of sleeves are provided to guide the tube, The sleeve has an inner diameter that allows the diameter of the annular portion to expand or contract within a predetermined range. A wire buffer device as described in any one of (1) to (5). This configuration prevents deterioration of the wire tube due to direct friction against the base when the diameter of the annular portion of the wire tube changes.
[0062] (7) A wire buffer device as described in any one of (1) to (6), The first feeding device, a push feeder, feeds the welding wire to the wire buffer device, A pull feeder, which is a second feeding device from which the welding wire is fed from the wire buffer device, A control unit, comprising, Buffer amount control system. With 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 feeding control of the welding wire by the first feeding device and the second feeding device more stable.
[0063] (8) A welding robot equipped with a wire buffer device as described in any one of (1) to (6), Equipped with a welding power source, Welding system. With this configuration, the buffer amount detected by the wire buffer device is fed back to the first and second feeding devices, which stabilizes the amount of welding wire fed to the welding torch, resulting in improved welding accuracy. [Explanation of Symbols]
[0064] 10 Wire buffer device 15 Auxiliary switch 20 Storage Units 20a Introduction Area 20b Containment area 20c sending area 21 base 21a Substrate section (base surface) 21b Edge 22 Wire entry point 23 Wire exit section 24 Guide section 25 Wire tube (tube) 25a Annular section 26 protective sleeves (sleeves) 26A First protective sleeve 26B Second protective sleeve 26C Third protective sleeve 26D 4th protective sleeve 26E 5th protective sleeve 27 recess 27A First recess 27B Second recess 27C Third recess 28 Lid 29 Fixed magnet 30. Sliding parts (sliding mechanisms) 30A First sliding part 30B Second sliding part 30C Third sliding part 31 Slider 32 Guide shaft 33 Support plate 34 Tube insertion section 35 Guide grooves 36 Ball bearing 36a Contact surface 37 Laura 38 1st support shaft 39 2nd support shaft 41. Crank section (crank mechanism, linkage mechanism) 42 Crank Axle 42a Shaft 42b Flange section 43 rods 43A First Rod 43B 2nd Rod 43C Third Rod 44 detection sensors 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 section 52 Guide pins (pins) 53 Guide groove 100 welding systems 110 Welding Robots 111 Welding Torch 120 Robot control devices 130 Welding Power Supply 131 Feeding Control Unit 140 Servo Amplifier 150 Pull feeder (second feeding device) 160 Push feeder (first feeding device) 200 work
Claims
1. A wire buffer device positioned between a first feeding device and a second feeding device, for controlling the amount of slack in the welding wire between the feeding devices, The wire buffer device is A wire inlet from which welding wire is fed from the first feeding device, A wire outlet section that feeds the welding wire toward the second feeding device, The annular portion is curved by crossing the wire inlet portion and the wire outlet portion, and the tube through which the welding wire is inserted, A base provided with a wire inlet, a wire outlet, and a housing area for housing the annular portion of the tube, A sliding mechanism comprising: a tube insertion portion arranged in the aforementioned housing area, through which the tube is inserted and which moves radially as the diameter of the annular portion expands and contracts; and a slider that moves together with the tube insertion portion; A crank mechanism comprising: a crankshaft pivotally supported at the center of the aforementioned containment area; and a rod whose longitudinal ends are connected to the slider and the crankshaft, respectively, and which rotates the crankshaft as the slider moves; A detection sensor for detecting the rotation angle of the crankshaft, Equipped with, Wire buffer device.
2. The sliding mechanism has a ball bearing or pin that moves along the surface direction of the base, The ball bearing or pin moves along the radial direction of the annular portion along the guide groove formed in the base. The wire buffer device according to claim 1.
3. The tube is attached to either the wire inlet or the wire outlet. The wire buffer device according to claim 1.
4. The tube insertion section has a roller mechanism for gripping the tube. The wire buffer device according to claim 1.
5. At least two or more of the aforementioned rods are provided. The connecting portion between the rod and the crankshaft is arranged at equal intervals on the outer edge side of the crankshaft. The wire buffer device according to claim 1.
6. Multiple sleeves are provided to guide the tube, The sleeve has an inner diameter that allows the diameter of the annular portion to expand or contract within a predetermined range. The wire buffer device according to claim 1.
7. A wire buffer device according to any one of claims 1 to 6, The first feeding device, a push feeder, feeds the welding wire to the wire buffer device, A pull feeder, which is a second feeding device from which the welding wire is fed from the wire buffer device, A control unit, comprising, Buffer amount control system.
8. A welding robot equipped with a wire buffer device according to any one of claims 1 to 6, Equipped with a welding power source, Welding system.