Positioner device

Abstract

To provide a positioner device capable of easily removing a ball screw 60 and reducing a work cost related to replacement work of the ball screw 60.SOLUTION: The positioner device includes a ball screw 60, a nut 65, and a bracket 80 for housing the nut 65. The bracket 80 has a cutout 82b wide enough for the ball screw 60 to pass through, and the cutout 82b is open to the front side of the figure. The ball screw 60 can be taken out to the front side of the drawing by removing the bolt 87 and removing the nut 65 downward from the bracket 80.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a positioner device for multi-dimensionally moving and positioning a workpiece, and a ball screw extraction method. [Background technology]

[0002] 2. Description of the Related Art It is common practice to attach processing tools such as nut runners and welding guns to the arms of multi-axis robots and use these processing tools to tighten bolts or weld workpieces such as car body parts. For reasons such as reducing the load on a multi-axis robot, it is desirable to be able to move the workpiece in multiple dimensions (including rotation and turning). Various positioner devices for such movement have been proposed (see, for example, Patent Document 1 (FIGS. 6, 7, and 8)).

[0003] Patent Document 1 will be explained with reference to the following figure. FIG. 14 is a side view of a conventional positioner device. As shown in Figure 14, the positioner device 200 comprises a base 201, a frame body 202 erected on the base 201, a ball screw 204 suspended from an upper cross beam 203 of the frame body 202, a nut 205 fitted onto (threaded onto) the ball screw 204, a bracket 206 fixed to the nut 205, and a lifting arm 207 extending laterally from the bracket 206.

[0004] A reducer 208 and an electric motor 209 are mounted on the frame 202. The reducer 208 and the ball screw 204 are connected by a coupling 211. The output of the electric motor 209 is reduced in speed by the reducer 208 and is used to rotate the ball screw 204 . When the ball screw 204 is turned, the nut 205 moves up or down, and the lifting arm 207 moves up or down. A workpiece is set on the tip of the lifting arm 207.

[0005] An enlarged view of part 15a in FIG. 14 is shown in FIG. 15(a), and an enlarged view of part 15b in FIG. 14 is shown in FIG. 15(b). 15(a), the ball screw 204 passes through the upper cross beam 203 from top to bottom and is supported by the upper cross beam 203 via a bearing unit 213. The bearing unit 213 has a flange 214. This flange 214 is placed on the upper cross beam 203 and fixed with bolts 215.

[0006] 15(b), the nut 205 also has a flange 216. This flange 216 is placed on the bracket 206 and fixed with a bolt 217. A ball (steel ball) 218 ​​is interposed between the ball screw 204 and the nut 205.

[0007] Roller bearings have a set lifespan. This lifespan shortens as the frequency of use increases and the load on the bearing increases. Furthermore, the lifespan shortens even further if an unexpected impact force is applied. The ball screw 204 is a type of roller bearing and has a limited lifespan, so it can be said to be a consumable item. When the lifespan is reached or before it is reached, the ball screw 204 and the nut 205 are replaced with new ones.

[0008] Although Patent Document 1 does not provide any explanation about replacing the ball screw, it is common to remove the ball screw 204 after removing any objects that may fall, such as the front lift arm 207.

[0009] However, because the work had to be done in a small space, replacement took time, resulting in increased work costs.

[0010] As various costs are being reduced, there is a demand for a positioner device that allows for easy removal of the ball screw and reduces the labor costs associated with replacing the ball screw. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 4371835 Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a positioner device in which the ball screw can be easily removed and the labor costs associated with replacing the ball screw can be reduced. [Means for solving the problem]

[0013] The invention according to claim 1 comprises a base, a frame body erected on the base and having an upper cross beam stretched across it, a ball screw rotatably attached to the upper cross beam and extending downward along a vertical axis, a nut fitted onto the ball screw, a bracket fixed to the nut, and a lifting arm extending from the bracket sideways through the front of the frame body to the outside and supported by the bracket so as to be rotatable around a horizontal axis, When the ball screw is rotated, the nut moves up and down, and the bracket and the lifting arm move up and down together with the nut, thereby moving and positioning the workpiece in multiple dimensions, the bracket has a notch with a width that allows the ball screw to pass through, the notch opening toward the rear surface side of the frame, The ball screw can be taken out from the rear surface of the frame through the notch. [Effects of the Invention]

[0014] In the invention of claim 1, the bracket has a notch wide enough for the ball screw to pass through. The existence of this notch allows the ball screw to be removed from the rear of the frame. Moreover, since the work is done on the rear, there is no need for a lifting arm, etc., so the working space is wider. Therefore, the present invention provides a positioner device in which the ball screw can be easily removed and the labor costs associated with replacing the ball screw can be reduced. [Brief explanation of the drawings]

[0015] [Figure 1] 1A is a front perspective view of a positioner device according to the present invention, FIG. 1B is an enlarged exploded view of part b in FIG. 1A, and FIG. 1C is a rear perspective view of the positioner device. [Figure 2] FIG. 2 is a rear view of the positioner device according to the present invention. [Figure 3] FIG. 3 is an enlarged view of part 3 of FIG. 2. [Figure 4] FIG. 4 is an enlarged view of part 4 of FIG. 2. [Figure 5] FIG. 2 is an exploded view of the bracket according to the present invention. [Figure 6] 5, (b) is a view taken along the line 6b-6b in FIG. 5, (c) is a cross-sectional view of the nut, and (d) to (e) are diagrams illustrating other embodiments. [Figure 7] FIG. 7 is an enlarged view of part 7 of FIG. [Figure 8] FIG. 4 is a cross-sectional view of a screw drop prevention mechanism. [Figure 9] 7. (a) is a cross-sectional view taken along line 9a-9a in FIG. 7, and (b) is a view taken along arrows 9b-9b in FIG. [Figure 10] FIG. 4 is a flow chart illustrating a ball screw removal method according to the present invention. [Figure 11] FIG. 10 is a perspective view of the main part of the positioner device to which a traverse shaft member and a traveling shaft member have been added. [Figure 12] 11. (a) is a view taken along the arrow 12a in FIG. 11, and (b) is a view taken along the arrow 12b in FIG. [Figure 13] 1A is a diagram for explaining a modified example of the bracket, FIG. 1B is a cross-sectional view taken along line bb in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line cc in FIG. [Figure 14] FIG. 1 is a side view of a conventional positioner device. [Figure 15] 14. (a) is an enlarged view of a portion 15a in FIG. 14, and (b) is an enlarged view of a portion 15b in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the present invention will be described below with reference to the accompanying drawings. [Example]

[0017] [Positioner device] As shown in FIG. 1(a), the positioner device 10 comprises a base 12 to be placed on a floor 11, a frame body 40 erected from the base 12, a lifting arm 20 extending horizontally from the front face 41F of the frame body 40, and a turntable 30 attached to the tip of the lifting arm 20 and supporting the workpiece. In this example, the sub-base 13 is placed on the base 12 and the frame 40 is erected on the sub-base 13, but it is also possible to omit the sub-base 13 and erect the frame 40 directly on the base 12.

[0018] [Arm lift] The lifting arm 20 is made up of, for example, a face plate 21 along the front face 41F of the frame 40, a rotary plate 22 rotatably attached to the face plate 21, and a square pillar 23 extending horizontally from the rotary plate 22.

[0019] [Support rod] As shown in FIG. 1(b), a seat 14 is provided at a predetermined location on the base 12, and a support rod 15 can be placed on the seat 14 and fixed with a bolt 16 before replacing the ball screw. This support rod 15 serves as a base on which the heavy lifting arm 20 is temporarily placed. For convenience of drawing, support rod 15 is drawn in FIG. 1(a), but support rod 15 is only necessary when replacing the ball screw, and is removed at other times and stored in a jig storage area or the like.

[0020] [Rear cover] As shown in FIG. 1(c), a rear surface 41B of the frame body 40 is covered with a rear surface cover . In this example, five rear covers 42 are used to cover the rear surface 41B of the frame body 40, but any number may be used. Each rear cover 42 is fastened to the frame body 40 with four bolts.

[0021] [Positioner device details] FIG. 2 is a rear view of the positioner device 10. As shown in FIG. 2, the positioner device 10 comprises a frame 40 that stands on a base 12 via a sub-base 13 and has an upper cross beam 43 spanning the top, a ball screw 60 that is attached to the upper cross beam 43 so as to be rotatable around a vertical axis and extends downward, a nut 65 that fits onto the ball screw 60, a bracket 80 that is fixed to the nut 65, a face plate 21 that is fixed to the bracket 80, a rotating plate 22 that is supported on the face plate 21 via a hollow shaft 27, and a lifting arm (FIG. 1(a), reference numeral 20) that is supported by the rotating plate 22 and extends toward the back of the drawing.

[0022] A rotation motor 24 is attached to the face plate 21, a pinion gear 25 is provided on the rotation motor 24, and a ring gear 26 is provided on the rotary plate 22. The rotational force is transmitted through the rotation motor 24 , pinion gear 25 and ring gear 26 in this order, and the rotating plate 22 rotates around the hollow shaft 27 .

[0023] 1(a) is rotated by a turning motor 31. A cable 32 for power supply and control of the turning motor 31 passes through the rectangular pillar 23 and reaches the inside of the frame 40.

[0024] [Back of frame] When the rear cover 42 shown in Fig. 1(c) is removed, a large, vertically elongated rectangular opening 44 appears as shown in Fig. 2, and 20 (4 x 5 = 20) female screw portions 40a appear on the frame 40, surrounding the opening 44. No intermediate bars are provided in the opening 44. Therefore, the ball screws 60 can be clearly seen through the opening 44.

[0025] [Ball screw] As shown in FIG. 2, the ball screw 60 is supported by the upper cross beam 43 and extends downward. A top plate 45 of the frame body 40 is arranged above the upper cross beam 43, a reducer 47 is mounted on this top plate 45 with a reducer shaft 46 extending downward, and an elevation motor 48 is mounted integrally on this reducer 47.

[0026] That is, a so-called electric motor with a reducer is suitable as the drive source 49 that rotates the ball screw 60. However, the drive source 49 may also be a hydraulic motor or an electric servo motor, and is not limited to an electric motor with a reducer. The reducer shaft 46 is connected to a ball screw 60 using a coupling 51 .

[0027] [nut] A nut 65 is screwed onto the ball screw 60. The structure of the nut 65 will be described in detail later with reference to FIG.

[0028] [Screw drop prevention mechanism] Preferably, a screw drop prevention mechanism 90 for preventing excessive drop of the ball screw 60 is provided below the ball screw 60. The configuration of the screw drop prevention mechanism 90 will be described in detail later with reference to Figs. 7 to 9(a) and (b).

[0029] The structure of the main parts of the positioner device 10 will be described in detail below with reference to the drawings.

[0030] [Upper bearing] As shown in FIG. 3, the ball screw 60 has, at its upper end, a medium diameter portion 61 having a smaller diameter than the general portion, and a small diameter portion 62 having a smaller diameter than the medium diameter portion 61, in this order from bottom to top. An upper bearing 55 is fitted into the upper cross beam 43 from above.

[0031] As long as it can bear the thrust load and radial load, a single upper bearing 55 may be used. The rolling elements contained in the bearing may be either balls or tapered rolls.

[0032] Alternatively, multiple angular ball bearings (two in this example, preferably four) may be stacked one above the other. Furthermore, the multiple angular ball bearings may include at least one bearing that receives an upward thrust load. Therefore, the configuration of upper bearing 55 is arbitrary and is not limited to the embodiment.

[0033] The upper bearing 55 includes, for example, an inner ring 56, an outer ring 57, and steel balls 58 sandwiched between them.

[0034] The medium diameter portion 61 is inserted into the inner ring 56 from below. Next, the lower lock nut 71 is screwed onto the medium diameter portion 61. When the lower lock nut 71 is turned, the ball screw 60 gradually rises. The step at the boundary between the general portion and the medium diameter portion 61 comes into contact with the inner ring 56.

[0035] Furthermore, the lower lock nut 71 is turned slightly to apply tension (apply axial force). In this state, the upper lock nut 72 is screwed in. This upper lock nut 72 prevents the lower lock nut 71 from loosening.

[0036] Furthermore, the small diameter portion 62 is inserted into the coupling 51 from below, and then fixed with a set screw 73. In this way, the reducer shaft 46 is mechanically connected to the ball screw 60.

[0037] [bracket] The bracket 80 shown in FIG. 2 may be a single thick plate bracket extending laterally, but is preferably a three-dimensional box-shaped bracket 81 as shown in FIG. The box-type bracket 81 has a hollow structure, so it can maintain the weight at the same level as a thick plate bracket. The box-type bracket 81 has a large height, so it can have significantly higher torsional rigidity and bending rigidity than a thick plate bracket.

[0038] To facilitate understanding of FIG. 4, an exploded view of FIG. 4 is presented in FIG. 5, the box-shaped bracket 81 is composed of, for example, a bottom plate 82, left and right side plates 83 extending upward from the left and right sides of the bottom plate 82, and a bridge plate 84 spanning the upper ends or upper portions of these side plates 83. Preferably, the bridge plate 84 is provided with a cylindrical cover 85 extending upward.

[0039] In this example, the side plates 83 are fixed to the bottom plate 82 by welding, and the bridge plate 84 is fastened to the side plates 83 with bolts 86. There is no problem in fixing the side plates 83 to the bottom plate 82 with bolts.

[0040] 6(a), the bridge plate 84 has a semicircular hole 84a, shown by an imaginary line, with a diameter slightly larger than that of the ball screw 60, and a notch 84b extending from the semicircular hole 84a. The notch 84b is wide enough to allow the ball screw 60 to pass through, and opens to the back surface 41B. The cylindrical cover 85 also has a cutout 85a in a part thereof.

[0041] The semicircular hole 84a may be changed to a rectangular hole 84c as shown in Fig. 6(d). The rectangular hole 84c may be a polygonal hole such as a square hole, a hexagonal hole, or an octagonal hole, and may have any number of corners. A notch 84b extends from the rectangular hole 84c. The length of one side of the rectangular hole 84c (the width in the drawing) is preferably the same as the width of the notch 84b, but may be different from the width of the notch 84b.

[0042] 6(b), the bottom plate 82 has a round hole 82a, shown by an imaginary line, that is slightly larger in diameter than the nut 65, and a notch 82b extending from the round hole 82a. The notch 82b is wide enough to allow the ball screw 60 to pass through, and opens to the back surface 41B.

[0043] The round hole 82a may be changed to a square hole 82c as shown in FIG. 6(e). The rectangular hole 82c may be a polygonal hole such as a square hole, a hexagonal hole, or an octagonal hole, and may have any number of corners. A notch 84b extends from the rectangular hole 82c.

[0044] As shown in FIG. 6(c), the nut 65 has a cylindrical portion 66 and a flange portion 67 that extends horizontally from the lower end of the cylindrical portion 66. Because the steel balls 68 are interposed between the grooves of the ball screw 60 and the nut 65, the nut 65 moves up or down extremely smoothly when the ball screw 60 is turned. However, the steel balls 68 are consumables with a limited lifespan.

[0045] 5, the flange 67 is placed on the bottom plate 82 from below. In this state, the nut 65 is fixed to the bottom plate 82 with the bolt 87. As a result, as shown in FIG. 4, most of the nut 65 is housed between the pair of left and right side plates 83. The ball screw 60 can be seen through the notch 85 a of the cover 85 .

[0046] [The role of the cover] 1(a), is laid inside the frame 40 through the hollow shaft 27, as shown in FIG. 2. Contact between the cable 32 and the ball screw 60 must be avoided. Therefore, a cover 85 is erected to prevent contact between the cable 32 and the ball screw 60.

[0047] [Details of the screw drop prevention mechanism] As shown in Figure 8, the screw drop prevention mechanism 90 includes a gate-shaped stay 91 attached to the base 12, a propeller member 97 housed in the gate-shaped stay 91 and fixed to the lower end of the ball screw 60 with a bolt 96, a plate 98 positioned below the propeller member 97, and a stopper piece 99 provided on the upper surface of the plate 98.

[0048] Preferably, the plate 98 is provided with a lateral groove 98a wider than the head of the bolt 96. The presence of the lateral groove 98a makes it easier to insert and remove the plate 98. It is even more preferable to have a central hole.

[0049] [Gate-type stay details] The gate-shaped stay 91 may have any structure, but preferably comprises a pair of left and right leg portions 93 secured to the sub-base 13 (or base 12) with bolts 92, and a cross portion 95 suspended across the tops (or upper ends) of these leg portions 93 and secured to the leg portions 93 with bolts 94. A front view of the screw drop prevention mechanism 90 having the above configuration is shown in FIG.

[0050] [Plate details] As shown in FIG. 9(b), the plate 98 is a substantially square plate having a central hole, and is fixed to a pair of left and right legs 93 with bolts 101. On the plate 98, one or more (four in this example) stopper pieces 99 are arranged along a turning circle 102 of the propeller member 97 shown by an imaginary line.

[0051] The stopper piece 99 may be a simple protrusion, but as shown in Figure 8, it is attached to the plate 98 in a semi-submerged state and removably. If the propeller member 97 were to fall while turning, the blades of the propeller member 97 (Figures 9(a) and (b), symbol 97a) would collide strongly with the stopper piece 99. If the stopper piece 99 is semi-submerged, it can withstand a large impact force. Furthermore, if the stopper pieces 99 are removable, they can be made of a different material (such as a high-hardness material) from that of the plate 98, thereby increasing the durability of the stopper pieces 99. In addition, if the stopper pieces 99 are removable, it is possible to replace only the damaged stopper pieces 99 while leaving the plate 98 as is.

[0052] [Lower Bearing] In FIG. 2, the upper bearing 55 that supports the ball screw 60 is essential, but since the support function of the nut 65 can be expected, it is optional whether or not to provide the lower bearing 105 shown in FIG. However, it is more desirable to actively prevent misalignment of the lower end of the ball screw 60 (the lower end of the ball screw 60 swinging left and right or front and back in the drawing), and in this case a lower bearing 105 is provided. The type and structure of the lower bearing 105 can be selected arbitrarily, but in this example, a self-aligning bearing is used.

[0053] As shown in Figure 8, the lower bearing 105 is made up of, for example, a flanged bearing housing 106 and a ball bearing 107 housed in this bearing housing 106. The outer ring of the ball bearing 107 has a spherical outer periphery. This spherical surface provides a self-aligning function.

[0054] That is, when the ball screw 60 receives a lateral load, it bends slightly. This bending causes the lower end of the ball screw 60 to tilt to the left or right in the drawing. At this time, the ball bearing 107 in the bearing housing 106 tilts in tandem with the ball screw 60. This tilting action is called the self-aligning action.

[0055] The lower bearing 105 is placed on the cross portion 95 of the gate-shaped stay 91 and fixed with a bolt 108. Then, in the ball screw 60 , the propeller member 97 is fitted onto the extension 63 that protrudes downward from the lower bearing 105 and fixed with the bolt 96 .

[0056] [Propeller parts] 9(a), the propeller member 97 has four blades 97a. The number of blades 97a is arbitrary, and may be two or three. A polygonal hole 97b is provided in the center of the propeller member 97. The extension portion 63 of the ball screw has a polygonal cross section. The extension portion 63 can be fitted into the polygonal hole 97b. The polygon may be a square, a hexagon, or an octagon.

[0057] [Screw drop prevention mechanism function] 8, a gap t of several millimeters is secured between the stopper piece 99 and the propeller member 97. In this position, the propeller member 97 is rotatable around the vertical axis. In this state, the positioning action of the positioner device 10 continues.

[0058] 2, if the ball screw 60 breaks at a position above the nut 65, the ball screw 60 below the breakage point will begin to fall while rotating, guided by the nut 65. That is, the ball screw 60 falls while rotating due to the weight of the lifting arm 20 and turntable 30, which are supported via the bracket 80 fixed to the nut 65.

[0059] Then, in FIG. 8, the gap t gradually decreases, exceeds zero, and becomes negative. 9(b), at least one of the blades 97a of the propeller member 97 collides with the stopper piece 99. Upon collision, the rotation of the propeller member 97 is stopped, and the ball screw (reference numeral 60 in FIG. 8) is prevented from falling any further.

[0060] 8, if there were no screw drop prevention mechanism 90, the ball screw 60 would drop at least several tens of millimeters, which would cause problems such as damage to the lifting arm 20, turntable 30, and lower bearing 105. In contrast, with the structure of FIG. 8, the ball screw 60 will only drop by a few millimeters, and problems such as damage to the lifting arm 20, turntable 30, and lower bearing 105 are avoided.

[0061] [Positioner device operation] 1(a), the workpiece placed on the turntable 30 is rotated around a rotation axis Ax1 passing through the center of the turntable 30, rotated around a horizontal axis Ax2 passing through the center of the rotating plate 22, and moved up or down along a vertical axis Ax3. Thus, the workpiece is moved and positioned three-dimensionally.

[0062] [Removing the ball screw] Next, the procedure for removing the ball screw 60 in the replacement work of the ball screw 60 will be described with reference to FIG. In step number (hereinafter abbreviated as ST) 01 in Fig. 10, the support rods are fixed to the predetermined positions on the base. Specifically, as shown in Fig. 1(b), the support rods 15 are placed on the seat 14 and fixed with bolts 16. In this example, two support rods 15 are prepared, but one or more may be prepared, and a support base may be placed on the seat 14 so as to cover one side thereof.

[0063] Next, the lifting arm 20 is lowered and placed on the support rod 15 (ST02). By placing the lifting arm 20 on the support rod 15, the load on the ball screw can be significantly reduced. Furthermore, since the bracket 80 and the lifting arm 20 do not need to be removed when pulling out the ball screw 60, the labor required for replacing the ball screw 60 can be reduced. Next, the rear cover 42 shown in FIG. 1(c) is removed (ST03).

[0064] When ST03 is completed, the upper bearing 55, the bracket 80, and the screw drop prevention mechanism 90 shown in FIG. 2 prevent the ball screw 60 from being removed. Therefore, in ST04, the screw drop prevention mechanism 90 is removed.

[0065] Specifically, in FIG. 8, the bolt 101 is removed and the plate 98 is pulled out to the front side of the drawing. Next, the bolt 96 is removed from the ball screw 60, the propeller member 97 is lowered, and the propeller member 97 is pulled out to the front side of the drawing.

[0066] Next, the bolts 94 are removed to free the legs 93 from the cross section 95. Next, the bolt 92 is removed, and the left leg 93 is moved to the left, and the right leg 93 is moved to the right, and the left and right legs 93 are removed.

[0067] Next, the lower bearing 105 is lowered together with the cross portion 95, and the lower bearing 105 is removed from the ball screw 60. Then, the lower bearing 105 is removed together with the cross portion 95. As a result of the above, the screw drop prevention mechanism 90 in FIG. 2 has been removed.

[0068] At ST05 in Figure 10, release the connection between the bracket and the nut and lower the nut. 4, the bolt 87 is loosened and removed from the bottom plate 82. Then, the nut 65 moves down by its own weight while freely rotating along the ball screw 60. As a result of this downward movement, the nut 65 comes completely out from the bottom plate 82.

[0069] Next, in ST06 in Figure 10, the coupling and ball screw are released from each other. Specifically, in FIG. 3, the setscrew 73 is loosened. Next, the upper lock nut 72 is loosened until it contacts the coupling 51 (or reaches the vicinity of the coupling 51) (ST07).

[0070] Next, the lower lock nut 71 is slowly turned (ST08), which causes the medium diameter portion 61 to come out of the inner ring 56 and the ball screw 60 to gradually move down. Once lowered, the upper lock nut 72 is removed from the ball screw 60 (ST09). Furthermore, the lower lock nut 71 is loosened and removed from the ball screw 60 (ST10). This disengages the ball screw 60 from the upper cross beam 43 .

[0071] At this point in time, in FIG. 2, the screw drop prevention mechanism 90 and the nut 65 have been removed, and the upper end of the ball screw 60 is located below the upper cross beam 43 . Therefore, in ST11 in FIG. 10, the ball screw is removed from the bracket while being moved laterally. 4, the nut 65 has been removed, so the ball screw 60 is pulled toward the front of the drawing. As a result, the ball screw 60 passes through the notches 82b, 84b, and 85a. As a result, the ball screw 60 is disengaged from the bracket 80.

[0072] In FIG. 2, the ball screw 60 is removed from the opening 44 on the rear surface of the frame 40 (FIG. 10, ST12). A new ball screw 60 can be set by reversing the procedure described above.

[0073] In FIG. 2, the height of the positioner device 10 is H2. The work of removing the ball screw 60 is performed within this height H2 range. Since H2 is, for example, about 2 m, the work is performed at a low altitude. If the work is performed at a low altitude, no special scaffolding is required. Furthermore, the top plate 45, the reducer 47, and the lifting motor 48 do not need to be removed. Therefore, according to the present invention, a positioner device 10 is provided in which the ball screw 60 can be easily removed and the labor costs associated with the replacement of the ball screw 60 can be reduced.

[0074] The positioner device 10 described above is a three-axis positioner device that can rotate, pivot, and raise and lower the workpiece based on the rotation axis Ax1, horizontal axis Ax2, and vertical axis Ax3, as explained in Figure 1(a). However, depending on the shape and structure of the workpiece and the type of processing, a 4-axis positioner device or a 5-axis positioner device may be required. Therefore, a specific example of a 5-axis positioner device will be explained below.

[0075] [Positioner device with a traverse shaft member and a running shaft member] As shown in FIG. 11, axes that are perpendicular to each other in a plan view are defined as a lateral axis Ax4 and a traveling axis Ax5, and the traveling axis Ax5 is defined to extend along the lifting arm 20, and the lateral axis Ax4 is defined to extend perpendicular to the lifting arm 20. The frame 40 further includes a lateral axis member 110 at its upper end, which extends along the lateral axis Ax4.

[0076] Preferably, the vertical displacement of one end and the other end of the traverse shaft member 110 is restrained by a support 111. The form, shape and structure of the support 111 are arbitrary.

[0077] Furthermore, the traverse shaft member 110 is provided with a first slider 112 that moves along the traverse axis Ax4, and this first slider 112 is provided with a traveling shaft member 120 that extends along the traveling axis Ax5. The traveling axis member 120 is provided with a second slider 121 that moves along the traveling axis Ax5, and the second slider 121 is provided with a working robot 122. As a result of the above, the positioner device 10 to which the lateral shaft member 110 and the traveling shaft member 120 are added is obtained.

[0078] [First slider] As shown in Figure 12(a), the first slider 112 is movably attached to the lateral shaft member 110 via a first rail 113 laid in front of the lateral shaft member 110 and a first slide block 114 guided by the first rail 113.

[0079] The attachment structure between each element is determined so as to prevent the first rail 113 from coming off the transverse shaft member 110, the first slide block 114 from coming off the first rail 113, and the first slider 112 from the first slide block 114. However, it is preferable to take additional measures. Therefore, a first drop prevention member 115 is provided between the first slider 112 and the lateral shaft member 110 to prevent the first slider 112 from dropping off the lateral shaft member 110.

[0080] [First fall prevention member] The structure of the first fall prevention member 115 is arbitrary, but for example, it may be composed of a square bar 116 placed on the upper and lower surfaces of the lateral shaft member 110, and a first hook 117 extending from the first slider 112 with its tip wrapping around the square bar 116.

[0081] The square bar 116 is not essential and may be a groove drilled in the transverse shaft member 110. However, the grooves are an element that reduces the strength of the transverse shaft member 110. On the other hand, the square bars 116 are an element that increases the strength of the transverse shaft member 110, so the square bars 116 are more preferable.

[0082] A clearance C1 is secured between the first hook 117 and the square bar 116, allowing sliding movement under normal circumstances and allowing the bar to be caught if dropped. Alternatively, a clearance is secured between the first hook 117 and a groove formed in the lateral shaft member 110. Normally, the clearance C1 is ensured, allowing the first slider 112 to move unimpeded. When the first slider 112 separates from the lateral shaft member 110 (when it is about to come off), the clearance C1 becomes zero, preventing (suppressing) the first slider 112 from falling (coming off) any further.

[0083] That is, the first fall prevention member 115 is preferably a first hook 117 that extends from the first slider 112 to the lateral shaft member 110 so as to normally allow movement of the first slider 112 and prevent the first slider 112 from falling when the first slider 112 separates from the lateral shaft member 110.

[0084] [Second slider] As shown in Figure 12(b), a steel strip 123 is attached to the underside of the traveling shaft member 120, a second rail 124 is laid on this steel strip 123, a second slide block 125 is fitted to this second rail 124 so as to be able to move freely, and a second slider 121 is attached to this second slide block 125. That is, the second slider 121 is movably attached to the traveling shaft member 120 via, for example, a steel band 123, a second rail 124, and a second slide block 125.

[0085] The steel strip 123 is attached to the traveling shaft member 120 so that a portion of the steel strip 123 protrudes from the traveling shaft member 120 . It is desirable that such a second slider 121 also be provided with a second drop prevention member 126.

[0086] [Second fall prevention member] The second fall prevention member 126 may have any structure, but may include, for example, a protruding portion 123a of the steel band 123 and a second hook 127 that extends from the second slider 121 and whose tip wraps around the protruding portion 123a of the steel band 123.

[0087] The steel strip 123 and the protruding portion 123a are not essential, and may be a groove formed in the traveling shaft member 120. However, the grooves are an element that reduces the strength of the traveling shaft member 120. On the other hand, the band steel 123 is an element that increases the strength of the traveling shaft member 120, so the band steel 123 is more preferable.

[0088] A clearance C2 is secured between the second hook 127 and the steel band 123, allowing sliding under normal circumstances and allowing the hook to be caught when dropped. Alternatively, a clearance is secured between the groove formed in the traveling shaft member 120 and the second hook 127. Normally, the clearance C2 is ensured, allowing unhindered movement of the second slider 121. When the second slider 121 separates from the traveling shaft member 120 (when it is about to come off), the clearance C2 becomes zero, preventing (suppressing) the second slider 121 from falling (coming off) any further.

[0089] That is, the second fall prevention member 126 is preferably a second hook 127 that extends from the second slider 121 to the running shaft member 120 so as to normally allow the second slider 121 to move and to prevent the second slider 121 from falling when the second slider 121 separates from the running shaft member 120.

[0090] It is desirable that the five-axis positioner device 10 be provided with both the first fall prevention member 115 and the second fall prevention member 126 described above, but it may be provided with only one of them.

[0091] [Example of bracket change] A modified example of the bracket 80 described with reference to FIG. 4 will be described with reference to FIGS. 13(a) to 13(c). As shown in Figure 13(a), a reinforcing plate 88 is placed between the rear side of the bottom plate 82 and the rear side of the bridge plate 84 and fixed with bolts 89. Since the rest is the same as in Figure 4, the reference numerals in Figure 4 will be used and detailed description will be omitted. The reinforcing plate 88 is removed when the ball screw 60 is replaced, but is otherwise left attached.

[0092] As shown in FIG. 13(b), the opening of the notch 84b provided in the bridge plate 84 is closed and reinforced by a reinforcing plate 88. Even if a bending force or a twisting force is applied to the bridge plate 84, the opening of the notch 84b will not open.

[0093] As shown in FIG. 13(c), the opening of the notch 82b provided in the bottom plate 82 is closed and reinforced by a reinforcing plate 88. Even if a bending force or a twisting force is applied to the bottom plate 82, the opening of the notch 82b will not open. According to this modification, the rigidity of the box-shaped bracket 81 can be further increased.

[0094] Based on the above, the present invention can be summarized as follows. The lifting device comprises a base (12), a frame (40) standing on the base (12) and having an upper cross beam (43) stretched across it, a ball screw (60) rotatably attached to the upper cross beam (43) and extending downward along a vertical axis (Ax3), a nut (65) fitted onto the ball screw (60), a bracket (80) fixed to the nut (65), and a lifting arm (20) extending laterally from the bracket (80) through a front face (41F) of the frame (40) and outward, and supported by the bracket (80) so as to be rotatable about a horizontal axis (Ax2), When the ball screw 60 is rotated, the nut 65 moves up and down, and the bracket 80 and the lifting arm 20 move up and down together with the nut 65, thereby moving and positioning the workpiece in multiple dimensions. The bracket 80 has a notch 82b with a width that allows the ball screw 60 to pass through, and the notch 82b opens to the rear surface 41B side of the frame 40, The ball screw 60 can be taken out from the rear surface 41B of the frame 40 through the notch 82b.

[0095] Preferably, the ball screw 60 is attached to the upper cross beam 43 in a manner that the ball screw 60 is inserted from below into an upper bearing 55 provided on the upper cross beam 43 and fixed to an inner ring 56 of the upper bearing 55, The ball screw 60 is rotated by a drive source 49 disposed on the ball screw 60. The drive source 49 is connected to the ball screw 60 via a coupling 51 .

[0096] A ball screw 60 is rotatably fixed to the inner ring 56 of the upper bearing 55, and this ball screw 60 can be suspended from the upper cross beam 43. In addition, by releasing the connection between the drive source 49 and the ball screw 60, the ball screw 60 can be pulled out downward.

[0097] Preferably, a gate-shaped stay 91 is attached to the base 12, The gate-shaped stay 91 has a pair of left and right leg portions 93 secured to the base 12 with bolts 92, and a cross portion 95 suspended across the upper portions of the leg portions 93 and secured to the leg portions 93 with bolts 94. A lower bearing 105 into which the ball screw 60 can be inserted from above is fixed to the cross portion 95 .

[0098] The lower bearing 105 can suppress misalignment of the ball screw 60. By removing the pair of legs 93, the lower bearing 105 can be pulled out downward from the ball screw 60.

[0099] Preferably, the ball screw 60 has an extension 63 that extends below the lower bearing 105; A propeller member 97 having blades 97a is attached to the extension portion 63. A plate 98 is placed between the pair of left and right legs 93 below the propeller member 97. The plate 98 has a stopper piece 99 on its upper surface that prevents the propeller member 97 from rotating when the propeller member 97 falls. Before the propeller member 97 falls, a gap t is maintained between the stopper piece 99 and the propeller member 97 in the height direction.

[0100] If the ball screw 60 were to break, the propeller member 97 would fall while rotating. When the propeller member 97 falls, its blades 97a would hit the stopper piece 99, restricting the rotation of the propeller member 97 and the rotation of the ball screw 60. As a result, the ball screw 60 is prevented from falling excessively.

[0101] Preferably, the extension 63 has a polygonal cross section (planar cross section), and the propeller member 97 has a polygonal hole 97b that fits into the polygonal cross section. After being fitted into the extension 63, the propeller member 97 is fixed with a bolt 96.

[0102] The propeller member 97 can be reliably rotated together with the ball screw 60.

[0103] Preferably, the base 12 has a seat 14 that receives a support rod 15 that temporarily supports the lifting arm 20 .

[0104] When removing the ball screw 60, the support rod 15 is placed on the seat 14 and fixed in place. The weight of the lifting arm 20 is supported by the support rod 15. As a result, the load on the ball screw 60 can be eliminated, and the ball screw 60 can be easily removed.

[0105] Preferably, the nut 65 has a cylindrical portion 66 and a flange portion 67 that extends horizontally from the lower end of the cylindrical portion 66, The bracket 80 is a box-shaped bracket 81 that can house the cylindrical portion 66 and can be fixed with a bolt 87 by abutting the flange portion 67 against the bottom, and the box-shaped bracket 81 is provided with the notch 82b.

[0106] The box-shaped bracket 81 has high rigidity. The highly rigid box-shaped bracket 81 can stably support the heavy lifting arm 20. In addition, the presence of the notch 82b allows the ball screw 60 to be removed from the box-shaped bracket 81 while moving it laterally.

[0107] Preferably, the rear surface 41B of the frame body 40 is covered with a rear cover 42, and when the rear cover 42 is removed, a vertically elongated opening 44 corresponding to the length of the ball screw 60 appears, and no intermediate bar is provided in this opening 44.

[0108] Since there is nothing obstructing the rear surface 41B of the frame body 40, the ball screw 60 can be easily removed from the opening 44 of the rear surface 41B.

[0109] Preferably, the box-shaped bracket 81 has a cover 85 on the top surface thereof that extends along the ball screw 60, and this cover 85 also has a notch 85a.

[0110] If the cable 32 is laid near the box-shaped bracket 81 and there is a risk that the cable 32 may come close to the ball screw 60, the cable 32 and the ball screw 60 can be separated by the cover 85.

[0111] Preferably, the step of releasing the connection between the bracket 80 and the nut 65 (FIG. 10, ST05); a step of disconnecting the upper cross beam 43 and the ball screw 60 (FIG. 10, ST06 to ST10); a step of removing the ball screw 60 from the bracket 80 while moving it laterally (FIG. 10, ST11); and a step of removing the ball screw 60 from the rear surface 41B of the frame 40 (FIG. 10, ST12).

[0112] The removal of the ball screw 60 is completed by lowering the ball screw 60 and moving it sideways. A method for removing the ball screw 60 is provided that can reduce the cost of replacing the ball screw 60.

[0113] The positioner device 10 of the present invention may be applied to welding lines and assembly lines in addition to metal processing lines.

[0114] Furthermore, the "notch" in claim 1 includes not only the notch 82b in the bottom plate 82 of the bracket 80 described in the examples, but also any separation structure that allows the ball screw 60 to be pulled out to the rear side, such as any bracket structure that allows the ball screw 60 to be pulled out to the rear side by removing a fixed block or the like. [Industrial Applicability]

[0115] The present invention is suitable for a positioner device used in conjunction with a work robot. [Explanation of symbols]

[0116] 10...positioner device, 12...base, 14...seat, 15...support rod, 20...lifting arm, 40...frame body, 41F...front, 41B...back, 42...back cover, 43...upper cross beam, 44...opening, 49...drive source, 51...coupling, 55...upper bearing, 56...inner ring, 60...ball screw, 63...extension part, 65...nut, 66...tubular part, 67...flange part, 80...bracket, 81...box-shaped bracket, 82...bottom plate, 82a...round hole, 82b...notch, 83...side plate, 84...bridge plate, 84a...semicircular hole, 84b...notch, 85...cover, 85a...notch, 90...screw drop prevention mechanism, 91...Gantry stay, 93...Leg, 95...Cross section, 96...Bolt, 97...Propeller member, 97a...Blade, 97b...Polygonal hole, 98...Plate, 99...Stopper piece, 105...Lower bearing, 110...Traverse shaft member, 112...First slider, 115...First fall prevention member, 117...First hook, 120...Travel shaft member, 121...Second slider, 122...Work robot, 126...Second fall prevention member, 127...Second hook, H2...Height, C1, C2...Clearance, t...Gap, Ax1...Rotation axis, Ax2...Horizontal axis, Ax3...Vertical axis, Ax4...Traverse axis, Ax5...Travel axis.

Claims

1. The lifting device comprises a base, a frame body erected on the base and having an upper cross beam stretched across it, a ball screw rotatably attached to the upper cross beam and extending downward along a vertical axis, a nut fitted onto the ball screw, a bracket fixed to the nut, and a lifting arm extending laterally from the bracket through the front of the frame body to the outside and supported by the bracket so as to be rotatable around a horizontal axis, When the ball screw is rotated, the nut moves up and down, and the bracket and the lifting arm move up and down together with the nut, thereby moving and positioning the workpiece in multiple dimensions, the bracket has a notch with a width that allows the ball screw to pass through, the notch opening toward the rear surface side of the frame, The positioner device is configured so that the ball screw can be taken out from the rear surface of the frame through the notch.

2. 2. The positioner device according to claim 1, the ball screw is attached to the upper cross beam in a manner that the ball screw is inserted from below into an upper bearing provided on the upper cross beam and fixed to an inner ring of the upper bearing, The ball screw is rotated by a drive source disposed on the ball screw, The drive source is connected to the ball screw via a coupling.

3. 3. The positioner device according to claim 2, A gate-shaped stay is attached to the base, The gate-shaped stay has a pair of left and right leg portions that are bolted to the base, and a cross portion that is hung across the upper portions of the leg portions and is bolted to the leg portions, a lower bearing into which the ball screw can be inserted from above is fixed to the cross portion;

4. 4. The positioner device according to claim 3, the ball screw has an extension extending below the lower bearing; a propeller member having blades attached to the extension; A plate is placed between the pair of left and right legs at a position below the propeller member, The plate has a stopper piece on its upper surface that prevents the propeller member from rotating when the propeller member falls onto the plate, The positioner device is configured to maintain a gap between the stopper piece and the propeller member in the height direction before the propeller member falls.

5. 5. The positioner device according to claim 4, A positioner device, wherein the extension portion has a polygonal cross section, the propeller member has a polygonal hole that fits into the polygonal cross section, and the propeller member is fixed with a bolt after being fitted into the extension portion.

6. The positioner device according to any one of claims 1 to 4, The base has a seat for receiving a support rod that temporarily supports the lifting arm.

7. 2. The positioner device according to claim 1, The nut has a cylindrical portion and a flange portion that extends horizontally from the lower end of the cylindrical portion, The bracket is a box-shaped bracket that can house the cylindrical portion and can be fixed with a bolt by placing the flange portion against the bottom, and the notch is provided in this box-shaped bracket.

8. 2. The positioner device according to claim 1, The rear surface of the frame is covered with a rear cover, and when the rear cover is removed, a vertically long opening corresponding to the length of the ball screw appears, and no intermediate crosspiece is provided in this opening.

9. 2. The positioner device according to claim 1, When axes that are perpendicular to each other in a plan view are defined as a lateral axis and a traveling axis, and the traveling axis is defined to extend along the lifting arm, and the lateral axis is defined to extend at a right angle to the lifting arm, a traverse shaft member extending along the traverse shaft is provided at the upper end of the frame, a first slider that moves along the traverse shaft is provided on the traverse shaft member, a traveling shaft member that extends along the traveling shaft is provided on the first slider, a second slider that moves along the traveling shaft is provided on the traveling shaft member, and a work robot is provided on the second slider; Further, the device may include one or both of a first fall prevention member and a second fall prevention member, the first fall prevention member is a member disposed between the first slider and the lateral movement shaft member and prevents the first slider from falling off the lateral movement shaft member, The second drop prevention member is a member disposed between the second slider and the traveling shaft member and prevents the second slider from dropping off the traveling shaft member.

10. 10. The positioner device according to claim 9, A positioner device wherein the first fall prevention member is a first hook extending from the first slider to the lateral shaft member so as to normally allow the first slider to move and to prevent the first slider from falling when the first slider separates from the lateral shaft member.

11. 10. The positioner device according to claim 9, A positioner device, wherein the second fall prevention member is a second hook extending from the second slider to the running shaft member so as to normally allow the second slider to move and to prevent the second slider from falling when the second slider separates from the running shaft member.

12. 8. The positioner device according to claim 7, The positioner device has a cover on the top surface of the box-shaped bracket that extends along the ball screw, and this cover also has a notch.

13. 2. A method for removing the ball screw from the positioner device according to claim 1, comprising: releasing the connection between the bracket and the nut; a step of releasing the connection between the upper cross beam and the ball screw; removing the ball screw from the bracket while moving it laterally; and removing the ball screw from the rear surface of the frame.

Images