Drive mechanism of a transport tool

Abstract

A drive mechanism of a conveyance tool is provided, which transmits a driving force of a motor to a swing shaft without an oil tank or oil application, and reduces a radial load on an output shaft of a speed reducer. A drive mechanism of a conveyance tool that drives a swing shaft that tilts a workpiece includes a motor, a speed reducer that has an output shaft arranged parallel to the swing shaft, reduces a rotation of the motor, and a link mechanism that links the swing shaft and the output shaft, the link mechanism having a first link portion that has a middle portion of a length direction fixed to the output shaft, a second link portion that has a middle portion of a length direction fixed to the swing shaft, a third link portion that links one end portion of the first and second link portions so as to be rotatable, and a fourth link portion that links the other end portion of the first and second link portions so as to be rotatable, the first and second link portions being arranged in parallel, and the third and fourth link portions being arranged parallel to a line segment that links a center axis of the output shaft and a center axis of the swing shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to a drive mechanism of a transfer tool. BACKGROUND

[0002] For example, it is known that a tandem press line in which press machines are arranged in a line is used when a workpiece such as a vehicle body panel is formed. In this case, in order to transfer the workpiece subjected to pressing to the next press machine, a robot in which a transfer tool is attached to the tip of an arm is sometimes used. The robot holds the workpiece by a suction pad or the like attached to the transfer tool and transfers the workpiece to the next press machine. In such workpiece transfer, it is required that the holding operation and the holding release operation can be performed even in a state in which the workpiece is inclined. As one of the methods corresponding to this requirement, a method in which a swing shaft is provided in the transfer tool and the transfer tool is caused to change the posture of the workpiece with respect to the transfer tool with the swing shaft as the center is known.

[0003] In the transfer of the workpiece using the transfer tool, it is sought to perform the transfer between the press machines at high speed to improve the cycle time. In order to improve the transfer capability, it is desired that the tip of the transfer tool is formed as light and compact as possible to thereby reduce the inertial force. Therefore, it is desired that the increase in the weight of the transfer tool is suppressed and a large transmission force to the swing shaft is ensured by using a small reduction machine in a small motor and achieving a large reduction ratio.

[0004] In Patent Literature 1, a transfer tool is disclosed which has a swing shaft for inclining a workpiece, a motor, and a reduction machine that reduces the rotation of the motor. The transfer tool further has a drive gear fixed to an output shaft of the reduction machine and a driven gear fixed to a rotation shaft of the swing shaft and transmitting the rotation of the drive gear.

[0005] Prior art documents

[0006] Patent documents

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2018-130771 SUMMARY

[0008] Problems to be solved by the invention

[0009] In order to normally drive the driving gear and the driven gear, an oil film (lubricating film) is required between the contacted tooth surfaces. In the absence of the oil film, since the contact between the tooth surfaces is the contact of metals with each other, abnormal wear of the tooth surfaces occurs and abnormal operation such as a positional deviation is caused. As a means for ensuring the oil film, there are a method of immersing the gear in an oil tank and a method of periodically applying oil that is not easily peeled off on the tooth surfaces. However, in the case of the method of immersing the gear in the oil tank, in order to avoid splashing of the oil, it is necessary to make the device into a sealed structure, whereby the device is upsized and difficult to assemble. In the case of the method of periodically applying oil on the tooth surfaces, in the case where the load applied to the gear is small or the rotational speed is low, the oil film is maintained on the tooth surfaces for a certain period without being peeled off, and thus the method of periodically applying oil on the tooth surfaces is effective. However, in the case where the load applied to the gear is large or the rotational speed is high, since the tooth surfaces become high temperature, the durability of the oil is also reduced, and thus it is difficult to maintain the oil film, and the oil application operation needs to be frequently performed.

[0010] In addition, in the reduction gear, in order to amplify the torque of the motor, there are a case where a gear is installed on the output shaft of the reduction gear, and a case where the gear becomes a larger size than expected. In addition to this, the operation of the swing shaft is swung only with a swing angle of about ±20 degrees, and the entire teeth of the gear are not used. As a result, only the teeth within the swing range are always used, and the smaller the swing angle, the greater the load that is always applied to the same teeth. Therefore, the load applied to the teeth becomes large, and on the other hand, the teeth that are not used become meaningless.

[0011] Also, since the gear has a pressure angle in its configuration, a radial component is inevitably generated at the time of torque transmission. The component of the gear installed on the output shaft of the reduction gear is received by the main bearing of the output shaft. In this case, according to the capacity of the main bearing, even if there is a margin for the transmission torque of the reduction gear, the performance with respect to the radial load acting on the main bearing is insufficient. In order to cope with the radial load, it is necessary to select a main bearing of a larger type, and thus there is a problem that the device is upsized.

[0012] Thus, a drive mechanism that does not necessarily require an oil tank or oil application to transmit the driving force of the motor to the swing shaft and that can also reduce the radial load on the output shaft of the reduction gear is desired.

[0013] Solution to the problem

[0014] One embodiment of the present disclosure is a drive mechanism of a transport tool that is provided to a transport tool that transports a workpiece and drives a swing shaft for tilting the workpiece with respect to the transport tool, the drive mechanism of the transport tool including: a motor; a speed reducer that has an output shaft arranged in parallel with the swing shaft and that reduces the rotation of the motor; and a link mechanism that links the swing shaft and the output shaft, the link mechanism including: a first link portion whose middle portion in the length direction is fixed to the output shaft; a second link portion whose middle portion in the length direction is fixed to the swing shaft; a third link portion that links one end portion of the first link portion and one end portion of the second link portion in a manner that allows the one end portion of the first link portion and the one end portion of the second link portion to rotate; and a fourth link portion that links the other end portion of the first link portion and the other end portion of the second link portion in a manner that allows the other end portion of the first link portion and the other end portion of the second link portion to rotate, the first link portion and the second link portion being arranged in parallel, and the third link portion and the fourth link portion being arranged in parallel with a line segment that links the center axis of the output shaft and the center axis of the swing shaft.

[0015] Effects of the invention

[0016] According to one embodiment, a drive mechanism of a transport tool that does not necessarily need a sump or oil application to transmit the driving force of a motor to a swing shaft and that can reduce the radial load on the output shaft of a speed reducer can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a perspective view that shows a robot system that includes a drive mechanism of a transport tool according to one embodiment of the present disclosure.

[0018] Figure 2 FIG. 2 is a perspective view that shows Figure 1 the transport tool in the robot system shown in FIG. 1.

[0019] Figure 3 FIG. 3 is a perspective view that shows Figure 1 the transport tool shown in FIG. 2 from the bottom side.

[0020] Figure 4 FIG. 4 is a schematic view that shows one embodiment of a link mechanism in the drive mechanism.

[0021] Figure 5 FIG. 5 is a view that explains the direction of the load generated by a bearing in the link mechanism shown in FIG. 4. Figure 4

[0022] Figure 6 ​is a diagram illustrating the direction of load generated at the bearing in the case where the both end portions of the link portion and the output shaft are not on the same straight line as a reference example.

[0023] Figure 7 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example.

[0024] Figure 8 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example. Figure 1 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example.

[0025] Figure 9 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example. Figure 8 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example.

[0026] Figure 10 is a diagram illustrating the direction of load generated at the bearing in the case where the end portion of the link portion is fixed to the output shaft as a reference example.

[0027] Explanation of reference numerals

[0028] 3: transfer tool; 5: drive mechanism; 51: swing shaft; 52: motor; 53: speed reducer; 54: output shaft; 51a, 54a: center axis; 6: link mechanism; 61: first link portion; 62: second link portion; 61a, 62a: upper end portion (one end portion); 61b, 62b: lower end portion (other end portion); 61c, 62c: central portion; 63: third link portion; 64: fourth link portion; 611, 612, 631, 641: stopper (first swing angle range limiting portion); 621, 622, 632, 642: stopper (second swing angle range limiting portion); L: line segment; W: workpiece. DETAILED DESCRIPTION

[0029] One embodiment of the present disclosure will be described in detail below with reference to the drawings.

[0030] As shown in Figure 1 , a robot system 1 according to one embodiment of the present disclosure holds a plate-shaped workpiece W such as a vehicle body panel by a robot 2 and transfers it to, for example, a press machine (not shown). In order to hold and transfer the workpiece W, a transfer tool 3 is installed at the top end of an arm portion 24 of the robot 2.

[0031] The robot 2 is a multi-joint robot that includes a base 22 fixed to a support table 21, a rotary base 23 supported by the base 22 so as to be rotatable relative to the base 22, an arm portion 24 provided at the top end of the rotary base 23 so as to be swingable, and a wrist unit 25 provided at the top end of the arm portion 24 so as to be multi-axially rotatable. The transfer tool 3 is installed at the top end of the wrist unit 25.

[0032] As shown in Figure 2 and Figure 3 , the conveyance tool 3 is provided with a frame 31 in a strip shape, a slide 32 arranged on a surface (a side of the wrist unit 25) of the frame 31, and a slide 33 arranged on a back surface (a surface on the side opposite to the wrist unit 25) of the frame 31. The slides 32, 33 are respectively attached to the surface and the back surface of the frame 31 in a manner that they can move along a guide rail 34 arranged in the length direction of the frame 31. The two slides 32, 33 are connected by a belt 35 arranged in a manner that it can rotate in the length direction of the frame 31.

[0033] On one end surface of the frame 31 in the width direction, a rack 36 is arranged in the length direction of the frame 31. As shown in Figure 3 , a pinion 371 is engaged with the rack 36. The pinion 371 is attached to an output shaft of a motor 37. The motor 37 is arranged on the slide 32 arranged on the surface side of the frame 31. Thus, when the motor 37 is driven, the slide 32 moves in one direction in the length direction of the frame 31. When the slide 32 moves in one direction, the belt 35 pulls the slide 33, thereby moving the slide 33 in the length direction of the frame 31 in a direction opposite to the slide 32. That is, the two slides 32, 33 are arranged on the frame 31 in a manner that they move in opposite directions in the length direction of the frame 31.

[0034] On the slide 33 arranged on the back surface side of the frame 31, a holding tool 4 is attached, which is provided with a plurality of suction cups 41 that suck the workpiece W, and the holding tool 4 can be swung by a driving mechanism 5 attached to the lower surface (a surface on the opposite side of the frame 31) of the slide 33. In detail, as shown in Figure 2 and Figure 3 , the driving mechanism 5 has a swing shaft 51 extending in the width direction of the frame 31. The swing shaft 51 protrudes to both sides in the width direction of the frame 31, and on both sides in the width direction of the frame 31, a support portion 42 of the holding tool 4 is coaxially attached. A plurality of branch portions 43 extending in a direction orthogonal to the length direction of the support portion 42 are extended from the support portion 42. The plurality of suction cups 41 are arranged on the branch portions 43.

[0035] As shown in Figure 3 , the driving mechanism 5 is provided with the swing shaft 51, a motor 52, a speed reducer 53 that reduces the rotation of the motor 52, and a link mechanism 6 (not shown in Figure 3 ). An output shaft 54 of the speed reducer 53 (not shown in Figure 3(Not shown) is configured parallel to the swing shaft 51 and is connected to the swing shaft 51 via the linkage mechanism 6. Therefore, when the motor 52 rotates within a predetermined angle range, the rotation of the motor 52, after being reduced in speed by the reducer 53, is transmitted to the swing shaft 51 via the output shaft 54 ​​of the reducer 53 and the linkage mechanism 6. Thus, the swing shaft 51 rotates around... Figure 3 The swing axis X shown swings at a specified angle, causing the workpiece W held by the holding tool 4 to tilt.

[0036] Next, refer to Figure 4 The linkage mechanism 6 will be explained.

[0037] The linkage mechanism 6 includes: a first linkage portion 61, which is fixed to the output shaft 54 ​​of the reducer 53; a second linkage portion 62, which is fixed to the swing shaft 51; and a third linkage portion 63 and a fourth linkage portion 64, which connect the two ends of the first linkage portion 61 and the second linkage portion 62 in a manner that allows the two ends of the first linkage portion 61 and the second linkage portion 62 to rotate, respectively. The first linkage portion 61, the second linkage portion 62, the third linkage portion 63, and the fourth linkage portion 64 are all composed of a metal rod extending in a straight line.

[0038] The first link portion 61 and the second link portion 62 are of equal length and arranged parallel to each other, thus forming a set of parallel links. The first link portion 61 is arranged parallel to the length direction of the output shaft 54. Figure 4 The first link 61 is fixed to the output shaft 54 ​​at the midpoint of its length direction (perpendicular to the plane of the paper). The second link 62 is configured to be perpendicular to the length direction of the swing shaft 51 (perpendicular to the plane of the paper), and the second link 62 is configured to be perpendicular to the output shaft 54 ​​at the midpoint of its length direction (perpendicular to the plane of the paper). Figure 4 The first link 61 is orthogonal to the direction perpendicular to the paper, and the middle part of the second link 62 in the length direction is fixed to the swing shaft 51. Specifically, in this embodiment, the middle part 61c of the first link 61 in the length direction is fixed to the output shaft 54, and the middle part 62c of the second link 62 in the length direction is fixed to the swing shaft 51.

[0039] The upper end 61a (one end) and lower end 61b (the other end) of the first link 61 are arranged in a straight line with the output shaft 54 ​​as the center. The upper end 62a (one end) and lower end 62b (the other end) of the second link 62 are arranged in a straight line with the swing shaft 51 as the center. The lengths of the upper end 61a and lower end 61b of the first link 61 centered on the output shaft 54 ​​are equal, and the lengths of the upper end 62a and lower end 62b of the second link 62 centered on the swing shaft 51 are equal.

[0040] The third link portion 63 and the fourth link portion 64 are equal in length and are arranged in parallel to each other, thereby constituting another set of parallel links. The end portion 63a of the third link portion 63 arranged on the side of the first link portion 61 is coupled to the upper end portion 61a of the first link portion 61 via a bearing 65 in a manner that the third link portion 63 is rotatable relative to the upper end portion 61a. The end portion 63b of the third link portion 63 arranged on the side of the second link portion 62 is coupled to the upper end portion 62a of the second link portion 62 via a bearing 66 in a manner that the third link portion 63 is rotatable relative to the upper end portion 62a. The end portion 64a of the fourth link portion 64 arranged on the side of the first link portion 61 is coupled to the lower end portion 61b of the first link portion 61 via a bearing 67 in a manner that the fourth link portion 64 is rotatable relative to the lower end portion 61b. The end portion 64b of the fourth link portion 64 arranged on the side of the second link portion 62 is coupled to the lower end portion 62b of the second link portion 62 via a bearing 68 in a manner that the fourth link portion 64 is rotatable relative to the lower end portion 62b.

[0041] The bearings 65, 66, 67, 68 can use sliding bearings or rolling bearings of a sealed type. In particular, sliding bearings such as oil-free bearings, etc. that have self-lubricating properties can achieve a larger gap compared to rolling bearings, and thus can average assembly errors. In addition, in the case where the capacity of the bearing for receiving load by a surface is insufficient, since the size of the bearing can be increased in the axial direction to cope with the situation, the radial size of the bearing can be suppressed from becoming large.

[0042] In this way, by coupling the first link portion 61, the second link portion 62, the third link portion 63, and the fourth link portion 64, the third link portion 63 and the fourth link portion 64 are arranged in parallel to a line segment L that links the center axis 54a of the output shaft 54 and the center axis 51a of the swing shaft 51. The line segment L is a line segment that is orthogonal to the length direction of the output shaft 54 and the swing shaft 51 when the link mechanism 6 is viewed in the axial direction of the output shaft 54 and the swing shaft 51, and that links the center axis 54a of the output shaft 54 and the center axis 51a of the swing shaft 51 at the shortest distance.

[0043] Further, in the first link portion 61, the second link portion 62, the third link portion 63, and the fourth link portion 64, equal length means that the length that functions as the link mechanism 6 is equal. That is, equal length of the first link portion 61 and the second link portion 62 means that the distance between the center axes of the bearings 65, 67 at the first link portion 61 and the distance between the center axes of the bearings 66, 68 at the second link portion 62 are equal in length. Equal length of the third link portion 63 and the fourth link portion 64 means that the distance between the center axes of the bearings 65, 66 at the third link portion 63 and the distance between the center axes of the bearings 67, 68 at the fourth link portion 64 are equal in length. However, equal length is not limited to strict equality in length, and can include a design-allowable error within a range that does not impair the function as the link mechanism 6.

[0044] Furthermore, in the first link section 61, the second link section 62, the third link section 63, and the fourth link section 64, parallelism is not limited to parallelism in a strict sense. Also, in the first link section 61 and the second link section 62, the central portion in the length direction is not limited to the central portion in a strict sense. These allowable design errors are permitted within the scope of not impairing the function of the linkage mechanism 6.

[0045] In the drive mechanism 5 with the linkage mechanism 6 configured in this way, when the output shaft 54 ​​is driven by the drive motor 52 via the reducer 53 at a predetermined angle, for example... Figure 4 When the first link 61 rotates counterclockwise, it tilts. As a result, the upper end 61a of the first link 61 moves towards the swing axis 51. Figure 4 (to the left) and the lower end 61b of the first link 61 moves away from the swing axis 51. Figure 4 The right side of the first link 62 moves, and in conjunction with this, the third link 63 rotates around bearings 65 and 66 and moves towards the swing shaft 51, while the fourth link 64 rotates around bearings 67 and 68 and moves away from the swing shaft 51. This causes the second link 62 to tilt in the same direction as the first link 61. Consequently, the driving force of the motor 52 is transmitted to the swing shaft 51, which swings at a predetermined swing angle in a counter-clockwise swing direction SW. During this swinging motion, the parallelism between the first link 61 and the second link 62, and between the third link 63 and the fourth link 64, remains substantially unchanged.

[0046] Next, refer to Figure 5 The function of the linkage mechanism 6 in the drive mechanism 5 will be explained.

[0047] like Figure 5 As shown, when the motor 52 drives the output shaft 54 ​​to generate a counterclockwise rotational torque Tq, radial loads F1 and F2 are generated in the bearings 65 and 67 in the directions indicated by the dashed arrows, respectively. If these radial loads F1 and F2 are decomposed into vectors, the radial loads F1 and F2 are respectively generated from the vertical direction ( Figure 5 Loads F1a and F2a in the vertical direction and in the horizontal direction Figure 5 The loads F1b and F2b are composed of loads in the left and right directions. Loads F1a and F2a act in opposite directions, and loads F1b and F2b act in opposite directions.

[0048] Since the central portion 61c of the first link portion 61 in the length direction is fixed to the output shaft 54, the length of the first link portion 61 from the output shaft 54 to the bearing 65 is equal to the length from the output shaft 54 to the bearing 67. Therefore, the load F1a and the load F2a are the same load, and the load F1b and the load F2b are the same load. The load F1a and the load F2a act in opposite directions, and the load F1b and the load F2b act in opposite directions. Therefore, the radial loads F1, F2 acting on the bearings 65, 67 cancel each other out. Thus, the radial load on the output shaft 54 of the reduction gear 53 is completely eliminated. The same effect of completely eliminating the radial load also works on the swing shaft 51.

[0049] On the other hand, as different from the first link portion 61 of the present disclosure Figure 6 As with the link portion 100 shown in the drawing, in the case where the link portion 100 is configured in a "く" shape so that the both end portions of the link portion 100 and the output shaft 200 are not on the same straight line, the loads F1a, F2a in the perpendicular direction when the radial loads F1, F2 generated at the bearings 301, 302 are vectorially decomposed act in the same direction. Therefore, a radial load of the amount of the sum of the loads F1a, F2a acts on the output shaft 200, and the radial load is not reduced. In this case, because of the loads F1a, F2a generated at the bearings 301, 302, a reaction force F3 for not moving the center of rotation is generated on the output shaft 200.

[0050] In addition, as different from the first link portion 61 of the present disclosure Figure 7 As with the link portion 400 shown in the drawing, in the case where the end portion of the link portion 400 is fixed to the output shaft 200, a load F4 of the same size and opposite direction as the radial load F2 generated at the bearing 303 acts on the output shaft 200, and the radial load is not reduced.

[0051] Thus, as described above, the drive mechanism 5 according to one embodiment of the present disclosure transmits the driving force of the motor 52 to the swing shaft 51 by the link mechanism 6 configured by using two sets of parallel links. Therefore, it is not necessary to coat oil or to provide an oil sump as required in the case where the driving force of the motor is transmitted to the swing shaft by the meshing of gears with each other as in the past, and the necessity of frequent maintenance is also reduced.

[0052] Further, the driving mechanism 5 according to one embodiment of the present disclosure also reduces the radial load on the output shaft 54 of the speed reducer 53, as compared with the case where the driving force is transmitted by the meshing of gears with each other. Thus, high life and downsizing of the speed reducer 53 can be expected. Since the load at the time of rotation of the output shaft 54 and the load at the time of rotation of the swing shaft 51 are each borne by two points of the bearings 65, 67 and the bearings 66, 68, the load is dispersed, and the load on the bearings 65, 66, 67, 68 is also reduced. Thus, the bearings 65, 66, 67, 68 can also be downsized.

[0053] The driving mechanism 5 that transmits the driving force by the link mechanism 6 can easily take measures to limit the swing angle of the swing shaft 51 within a certain range, as compared with the case where the driving force is transmitted by the meshing of gears with each other. By limiting the swing angle of the swing shaft 51 within a certain range, it is thereby possible to prevent the swing shaft 51 from excessively rotating, i.e., to prevent the work W from excessively tilting.

[0054] Figure 8 and Figure 9 An example of measures for limiting the swing angle of the swing shaft 51 within a certain range is shown. In Figure 8 and Figure 9 In the first link portion 61, four-cornered stoppers 611, 612 are respectively attached to the faces facing the second link portion 62 at both end portions 61a, 61b. In the second link portion 62, four-cornered stoppers 621, 622 are respectively attached to the faces facing the first link portion 61 at both end portions 62a, 62b. In contrast, in the third link portion 63, triangular stoppers 631, 632 are respectively attached to the faces facing the fourth link portion 64 at both end portions 63a, 63b. In the fourth link portion 64, triangular stoppers 641, 642 are respectively attached to the faces facing the third link portion 63 at both end portions 64a, 64b.

[0055] When the output shaft 54 is rotated by more than a certain angle in the counterclockwise direction, as shown in Figure 8 the stopper 612 of the first link portion 61 comes into abutment with the stopper 641 of the fourth link portion 64, causing the first link portion 61 to interfere with the fourth link portion 64. At the same time, the stopper 621 of the second link portion 62 comes into abutment with the stopper 632 of the third link portion 63, causing the second link portion 62 to interfere with the third link portion 63. Thus, the output shaft 54 cannot continue to be rotated in the counterclockwise direction, and the swing angle range of the swing shaft 51 in the counterclockwise direction is limited.

[0056] As shown in Figure 9As shown, when the output shaft 54 is rotated more than a certain angle in the clockwise direction, the stopper 611 of the first link portion 61 abuts against the stopper 631 of the third link portion 63, causing the first link portion 61 to interfere with the third link portion 63. At the same time, the stopper 622 of the second link portion 62 abuts against the stopper 642 of the fourth link portion 64, causing the second link portion 62 to interfere with the fourth link portion 64. Thus, the output shaft 54 cannot continue to be rotated in the clockwise direction, and the range of the swing angle of the swing shaft 51 in the clockwise direction is limited.

[0057] Each of the stoppers 611, 612, 621, 622, 631, 632, 641, 642 can be provided to each of the link portions 61, 62, 63, 64 in a detachable manner, or can be provided integrally in a non-detachable manner.

[0058] In Figure 8 and Figure 9 , the combination of the stopper 612 and the stopper 641 and the combination of the stopper 611 and the stopper 631 constitute a first swing angle range limiting portion that limits the range of the swing angle of the swing shaft 51 by causing the first link portion 61 to interfere with the third link portion 63 and the fourth link portion 64. In addition, the combination of the stopper 621 and the stopper 632 and the combination of the stopper 622 and the stopper 642 constitute a second swing angle range limiting portion that limits the range of the swing angle of the swing shaft 51 by causing the second link portion 62 to interfere with the third link portion 63 and the fourth link portion 64. The link mechanism 6 can have at least one of the first swing angle range limiting portion and the second swing angle range limiting portion.

[0059] In the above embodiment, the central portions 61c, 62c of the first link portion 61 and the second link portion 62 in the lengthwise direction are fixed to the output shaft 54 and the swing shaft 51, respectively, but this is not limiting. For example, as shown in Figure 10 , the first portion 61A of the first link portion 61 from the output shaft 54 to the bearing 65 can have a different length from the second portion 61B from the output shaft 54 to the bearing 67, and the first portion 62A of the second link portion 62 from the swing shaft 51 to the bearing 66 can have a different length from the second portion 62B from the swing shaft 51 to the bearing 68. However, the first portions 61A, 62A are equal in length, and the second portions 61B, 62B are equal in length. Thus, the third link portion 63 and the fourth link portion 64 are arranged in parallel.

[0060] In this way, in the case where the central portions 61c, 62c of the first link portion 61 and the second link portion 62 in the lengthwise direction are not fixed to the output shaft 54 and the swing shaft 51, respectively, the radial load acting on the output shaft 54 and the swing shaft 51 is not completely eliminated. However, Figure 5The case where the vertical loads F1a, F2a are in opposite directions as shown is unchanged. Thus, an effect of reducing the radial loads acting on the output shaft 54 and the swing shaft 51 can be obtained.

[0061] Further, the drive mechanism 5 in the above embodiment has the housing 50 in which the link mechanism 6 is housed. However, the drive mechanism 5 can not have the housing 50.

Claims

1. A drive mechanism for a conveying tool, disposed on a conveying tool for conveying a workpiece, and driving a swing shaft, the swing shaft being used to tilt the workpiece relative to the conveying tool, the drive mechanism of the conveying tool comprising: motor; A speed reducer having an output shaft arranged parallel to the oscillating shaft, and the speed reducer reducing the rotational speed of the motor; and A linkage mechanism connects the swing shaft and the output shaft. The linkage mechanism has the following characteristics: A first link portion, the middle part of which is fixed to the output shaft in the longitudinal direction, moves as the output shaft rotates; The second link portion, the middle part of which is fixed to the swing axis in the longitudinal direction; The third link connects one end of the first link and one end of the second link in a manner that allows one end of the first link and one end of the second link to rotate. as well as The fourth link connects the other ends of the first link and the other ends of the second link in a manner that allows rotation between the other ends of the first link and the second link. The first link section and the second link section are arranged in parallel. The third and fourth connecting rods are arranged parallel to the line segment connecting the central axis of the output shaft and the central axis of the swing shaft. The rotation of the output shaft of the reducer is directly transmitted to the swing shaft via the first link, the second link, the third link, and the fourth link of the linkage mechanism. The first connecting rod portion is configured to be orthogonal to the length direction of the output shaft. The second link is configured to be orthogonal to the length direction of the swing axis.

2. The driving mechanism of the conveying tool according to claim 1, wherein, The central portion of the first connecting rod in the longitudinal direction is fixed to the output shaft. The central portion of the second connecting rod in the longitudinal direction is fixed to the swing shaft.

3. The drive mechanism of the conveying tool according to claim 1 or 2, wherein, It also includes at least one of a first swing angle range limiting part and a second swing angle range limiting part. The first swing angle range limiting part limits the swing angle range of the swing axis by causing the first link part to interfere with the third link part and the fourth link part. The second swing angle range limiting part limits the swing angle range of the swing axis by causing the second link part to interfere with the third link part and the fourth link part.

Images