JP3490980B2 - Transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrying device mounted on a robot and extending a carrying distance by the robot.

[0002]

2. Description of the Related Art For example, a robot has been conventionally used to convey a work as an object to be conveyed between press machines, and an arm of the robot is reciprocally moved between the press machines. In recent years, along with the increase of the transport distance, there are cases where the robot cannot be transported only by the reciprocating movement of the arm. In such a case, the transport device is attached to the wrist of the robot to extend the transport distance.

As such a transfer device, there is a device that uses a link mechanism and bidirectionally expands and contracts the link mechanism in synchronization with the movement of the robot arm. The link mechanism has, for example, a first link and a second link, the base end of the first link is connected to the wrist of the robot, and the second link is rotatably connected to the tip of the first link. At the tip of 2 links,
A holding means for holding the work is attached and configured.

A motor, which is a drive source of the conveying device, is attached to the base end of the first link, and the first link is rotated by this motor. Further, the second link is driven to rotate in synchronization with the rotation of the first link. Therefore, the link mechanism expands and contracts in both directions by driving the motor in synchronization with the reciprocating motion of the robot arm.

Power transmission means is built in the first link in order to transmit the rotation of the first link by the motor to the second link to rotate the second link as a follower. As the power transmission means, for example, a pulley and a belt can be considered.

When a belt and a pulley are used as the driven rotation means, the weight can be reduced, but it is difficult to transmit a large rotation torque with high rigidity. In order to transmit high rotational torque with high rigidity using a belt,
It is necessary to increase the belt width, tension or pulley diameter. However, in order to increase the tension, it is necessary to increase the strength of the frame of the link, which causes an excessive weight. In addition, when the width of the belt is increased, the thickness of the link is increased. Also,
If the pulley diameter is increased, the width of the link will be increased.

Since it is desired that the conveying device be flat, small and compact, it is desirable to avoid increasing the belt width and the pulley diameter.

Further, when a belt is used, there is a problem that the rigidity of the transmission system becomes low. That is, there is a problem that the belt is swayed laterally with respect to the rectilinear movement direction due to stretching of the belt or the holding means is easily moved by lateral force.

Particularly, when the link becomes long, the belt becomes long, and the force for driving the link mechanism also increases exponentially, so that the elongation of the belt further increases. as a result,
The swing width in the lateral direction also increases exponentially, and there is a limit to the usable transport distance.

Further, as a method of transmitting a rotational force without using a belt and a pulley, there is a method of using a gear train.

Since it is desired that the conveying device be flat and compact, it is desirable to avoid increasing the belt width and the pulley diameter. In particular, in a transfer device used for transfer between presses, a flat shape is desired because the tip portion enters the press machine.

Due to the above problems, a method of combining a gear train and a belt can be considered as a lightweight and flat power transmission method. That is, by decelerating using the gear train, the tension of the belt transmission portion is suppressed and transmitted. As a result, the number of gears can be minimized, and a belt can be used for the long-distance transmission unit, and a flat, lightweight, and compact transmission unit can be configured.

[0013]

However, in this case, since the belt is used as the long distance transmission unit, there is a problem that the rigidity of the drive system is lowered. That is, there is a problem that the holding means is swayed in the lateral direction with respect to the rectilinear movement direction due to the stretching of the belt or the like, and the holding means is easily moved by the lateral force. In particular, the longer the link, the longer the belt, and the greater the belt stretches.
As a result, the rigidity of the drive system is further reduced. in this way,
The effect of improvement is small in the configuration in which the belt and the gear are combined.

An object of the present invention is to provide a conveying device which can transmit high torque over a long distance and has a highly rigid drive system.

[0015]

SUMMARY OF THE INVENTION According to the present invention, a holding means for holding an object to be conveyed is mounted on the wrist of a robot and is moved in both directions in synchronization with the reciprocating motion of the robot so that the object to be conveyed is conveyed straight ahead. In the carrying device, the base end is attached to the wrist of the robot, the holding means is attached to the tip, and the link mechanism expands and contracts bidirectionally in synchronization with the reciprocating motion of the robot, and the base end of the link mechanism. And a drive source for driving the link mechanism, and provided in the link mechanism,
Driven rotation means for driven rotation of the link based on the rotational power of the drive source using a shaft and a bevel gear, wherein the drive source is arranged so that its rotation axis is parallel to the shaft. Is a transport device.

According to the present invention, the link mechanism comprises, for example, two links, and the first link is attached to the wrist of the robot and the second link is attached to the tip of the first link. A drive source attached to the base end of the first link rotationally drives the first link. The driven rotation means transmits the rotation of the first link to the second link, and rotates the second link in synchronization with the rotation of the first link.

In the present invention, the driven rotation means uses a shaft and a bevel gear. That is, since the rotation of the drive source is transmitted by the shaft, the drive system can have higher rigidity than transmission by the belt. Further, it can be made flat as compared with a structure using a belt and a pulley. Further, it can be made lighter than the structure using the gear train. In this way, since it is lightweight, the load weight on the robot can be reduced, and by making the drive system highly rigid, a robot system for handling that can increase the conveying speed and extend the conveying distance is constructed. It Further, since it is flat, it is suitable for conveyance between presses for placing a work or the like in a narrow space between machines.

According to the present invention, the drive source is arranged so that the rotation axis of the drive source is parallel to the shaft, that is, the drive source is arranged laterally, so that the drive unit can be made compact.

The present invention relates to a carrying device which is attached to a wrist of a robot and which moves a holding means for holding an object to be transferred bidirectionally in synchronization with a reciprocating motion of the robot, thereby carrying out straight transfer of the object to be transferred. The base end is attached to the wrist of the robot, the holding means is attached to the tip, and the link mechanism is provided at the base end of the link mechanism and the link mechanism that expands and contracts in both directions in synchronization with the reciprocating motion of the robot. A drive source for driving the drive mechanism, and a driven rotation means provided in the link mechanism and driven by the shaft and the bevel gear to rotate the link based on the rotational power of the drive source. One end of the drive mechanism is attached to the robot arm. The other end is attached to the link mechanism, and a force is applied in the direction of contraction to reduce the load on the wrist of the robot.
5 is provided.

According to the invention, the load on the robot can be reduced by providing the load reducing means using a spring or the like. As a result, the transportable weight can be increased.

The driven rotating means of the present invention has a first bevel gear fixed to both ends of the shaft, and a second bevel gear meshing with the first bevel gear. Is the second
Is meshed with the bevel gear from the outside of the shaft, and the intersection of the axis of the second bevel gear and the axis of the shaft is on the extension of the axis of the shaft to the outside.

According to the invention, the intersection of the axis line of the second bevel gear and the axis line of the shaft is on the extension of the shaft axis line to the outside. The effect of this will be described in comparison with the configuration shown in FIG. FIG. 15 is a diagram showing the structure of a driven rotation means used for a joint of a conventional robot, which is disclosed in Japanese Patent Application Laid-Open No. 8-47878 "joint mechanism". The mechanism disclosed in this publication has a pair of first bevel gears 101, 102 fixed to both ends of a shaft 100, and a pair of dish-shaped second bevel gears 103, 104 meshing with these, The shaft 105 of one of the second bevel gears 103 is rotationally driven by the motor, and the second link is connected to the shaft 106 of the other second bevel gear 104, whereby the rotational force of the motor is transmitted to the second link.

In this mechanism, one of the second bevel gears 103
The first bevel gear 101 that meshes with the second bevel gear 10 has a dish shape.
It meshes with 3 from the inside. That is, the second bevel gear 1
Since the intersection of the axis L1 of 05 and the axis L2 of the shaft 100 exists inside the shaft 100,
As a result, there is a problem in that the thickness of the first link that incorporates the driven rotation means becomes large, and the configuration becomes large.

On the other hand, the driven rotation means of the present invention is
The first bevel gear fixed to the shaft meshes with the disc-shaped second bevel gear from the outside, and the intersection of the axis of the second bevel gear and the axis of the shaft extends to the outside of the shaft axis. It is on extension. That is, the shaft is configured not to be arranged on the dish-shaped second bevel gear. With this configuration,
It can be made thinner than the prior art shown in FIG.

The driven rotating means of the present invention has a pair of first bevel gears fixed to both ends of the shaft, and a pair of second bevel gears meshing with the first bevel gear, The second bevel gear that meshes with one end and the second bevel gear that meshes with the other end mesh from opposite sides with respect to the axis of the shaft.

When the link mechanism has the first link and the second link, it is necessary to rotate the first link and the second link in opposite directions in order to extend and contract the link mechanism. In the present invention, the second bevel gear that meshes with both ends of the shaft is
By configuring the shafts so that they engage with each other from opposite sides, it becomes possible to rotate the first link and the second link in opposite directions. Therefore, the driven rotation means can be made flat with a simple configuration having a small number of parts.

The driven rotating means of the present invention has a pair of first bevel gears fixed to both ends of the shaft, a pair of second bevel gears meshing with the first bevel gear, and a driven rotating direction. A second bevel gear that has a gear for matching and that meshes with one end of the shaft and a second bevel gear that meshes with the other end of the shaft mesh with each other from the same side with respect to the axis of the shaft. Characterize.

In the present invention, the second bevel gear that meshes with both ends of the shaft is meshed from the same side with respect to the shaft, and one gear is provided to reverse the driven rotation direction and align the rotation direction. . In this way, by engaging the pair of second bevel gears from the same side with respect to the shaft, the space inside the frame in which the shaft is contained can be effectively used, and the shaft can be made flatter.

In the present invention, in the preceding stage of the driven rotation means,
A speed increasing mechanism is provided, and a speed reducing mechanism is provided at a subsequent stage.

According to the invention, since the speed increasing mechanism is provided in the front stage of the driven rotating means and the speed reducing mechanism is provided in the rear stage thereof, the rotational speed of the shaft can be increased and the rotational torque transmitted by the shaft can be suppressed small. . As a result, the outer diameter of the shaft can be reduced, and the width and weight of the shaft can be reduced. Moreover, the diameter of the first bevel gears at both ends of the link can be reduced by the speed increasing / decelerating mechanism. This allows
The thickness of the link can be reduced. Therefore,
The transport device can be made compact and operability is improved.

The driven rotating means of the present invention is characterized in that the holding means attached to the tip of the link mechanism is driven to rotate based on the rotation of the link, and the object to be transferred is conveyed at a constant posture during the conveyance. To do.

According to the present invention, the holding means provided at the tip of the link mechanism is also driven to rotate by the driven rotation means. Thereby, the transported object can be transported in a non-inverted manner.

According to the present invention, the holding means, which is attached to the wrist of the robot and holds the object to be conveyed, is moved in both directions in synchronization with the reciprocating motion of the robot, so that the object to be conveyed is linearly conveyed, and the base end portion is provided. Is attached to the wrist of the robot, the holding means is attached to the tip of the robot, and the link mechanism that expands and contracts in both directions in synchronization with the reciprocating motion of the robot is provided at the base end of the link mechanism to drive the link mechanism. And a driven rotation means that is provided in the link mechanism and that rotates the link based on the rotational power of the drive source using a shaft and a bevel gear, and the driven rotation means is the link mechanism. In a transport device that transports the holding means attached to the tip end part according to the rotation of the link and transports the transported object while keeping the posture constant, the link mechanism is attached to the wrist of the robot. First having a base end
It has a link 10 and a second link 11 that is rotatably connected to the tip of the first link 10 about the axis J7 and that has the tip portion to which the holding means is attached. It has a first driven rotation means 20 built in the link 10 and a second driven rotation means 21 built in the second link 11, and the first driven rotation means 20 is at the base end portion of the first shaft. A first bevel gear fixed to one end and the other end that is the tip of the first link 10, and a second bevel gear that meshes with the first bevel gear. The bevel gear meshes with the second bevel gear from the outside of the first shaft, and the intersection of the axis of the second bevel gear and the axis of the first shaft is extended to the outside of the axis of the first shaft. Yes, second
The driven rotating means 21 includes a third bevel gear fixed to one end of the second shaft on the tip side of the first link 10 and another end of the first shaft on the other end. A fourth bevel gear that meshes with the third bevel gear, and the third bevel gear meshes with the fourth bevel gear from the outer side of the second shaft to form an axis line of the fourth bevel gear and an axis line of the second shaft. The intersection is on the extension of the axis of the second shaft to the outside, and is accelerated by the first and second bevel gears at the one end of the first shaft of the first driven rotation means 20, and the The speed is reduced by the first and second bevel gears at the other end, and is increased by the third and fourth bevel gears at the one end of the second shaft of the second driven rotation means 21, and the other end of the second shaft is accelerated. The conveyor device is characterized in that the speed is reduced by the third and fourth bevel gears of the section.

[0034]

1 is a perspective view showing a transfer system in which a multi-joint robot 2 is equipped with a transfer device 1 according to an embodiment of the present invention. This transfer system is installed, for example, between two press machines, and is used for transfer between two points for transferring a work from one press machine to the other press machine.

The robot 2 is a 6-axis vertical articulated robot in this embodiment, and has a base 3, a lower arm 4, an upper arm 5 and a wrist 6. The lower arm 4 is attached to the base 3, the upper arm 5 is attached to the tip of the lower arm 4, the wrist 6 is attached to the tip of the upper arm 5, and the carrier device 1 is attached to the wrist 6.

The base 3 is rotatable about a vertical first axis J1, and the lower arm 4 is angularly displaceable about a horizontal second axis J2 about a base end connected to the base 3. Is.
The upper arm 5 can be angularly displaced about a horizontal third axis J3 around a base end portion attached to the tip of the lower arm 4, and can be angularly displaced about a fourth axis J4 which is the axis of the upper arm 5. Is. The wrist 6 attached to the tip of the upper arm 5 is angularly displaceable around a fifth axis J5 perpendicular to the axis of the upper arm 5, and the carrier device 1 is attached to the wrist 6.

The carrier device 1 is a carrier device body 12 which is a link mechanism having a first link 10 and a second link 11.
And a holding means 13 attached to the front end of the carrier body 12 for holding a work. Transport device body 12
The first link 10 has a proximal end attached to the wrist 6. The second link 11 is rotatably connected to the tip of the first link 10 about a seventh axis J7 parallel to the sixth axis.

The servo motor 1 is provided at the base end of the first link.
4 are provided. The servomotor 14 is a drive source that rotationally drives the first link around the sixth axis J6. The first driven rotation means 20 is built in the first link 10. The first driven rotation means 20 transmits the rotation of the first link 10 by the servomotor 14 to the second link 11 to cause the first link 10 to rotate. The second link 11 is driven to rotate in synchronization with the rotation.

By driving the servo motor 14, the expanded state where the first link 10 and the second link 11 are in a relationship of about 180 ° is changed to the contracted state where the first link 10 and the second link 11 are overlapped. As described above, the conveyance device body 12 further expands and contracts from the contracted state to the expanded state. Such a carrier device 1 expands and contracts in both directions in synchronization with the swing of the arm of the robot 2 to carry a long distance.

The holding means 13 attached to the tip of the second link 11 is rotatable about the eighth axis J8 which is parallel to the seventh axis J7. In the second link 11, the second link 1
In synchronization with the rotation of 1, the second driven rotation means 21 for driving the holding means 13 to be driven is incorporated. Therefore, when the servo motor 14 is rotationally driven, the first driven rotation means 2
With 0, the second link 11 is driven to rotate with respect to the first link 10, and the second driven rotation means 21 causes the holding means 13 to be driven to rotate with respect to the second link 11. The holding means 13 holds the work by suction.

Next, the transfer operation of the robot 2 will be described with reference to FIG. Robot 2 is press machine 8
It is arranged between 0 and 81 and bidirectionally expands and contracts to convey the work W from one press 80 to the other press 81. As shown in FIG. 12 (1), one press machine 8
When holding the work at 0, the robot 2 moves the arm 4,
5 is extended toward the one press 80, and the conveying device 1 is also extended. Then, the work is sucked and held by the holding means 13 provided at the tip of the transport device 1.

Then, as shown in FIG. 12 (2), when the arms 4 and 5 are swung to the center from the state where they are extended to one side, the carrier device 1 contracts from the state where they are extended. 12
As shown in (3), the arms 4, 5 swung to the center
Is further extended to the other side as shown in FIG.
(4) As shown in (5), the transport device 1 also extends to the other side. In this way, the work W can be conveyed from the one press 80 to the other press 81. Also,
The link length of the first link 10 (between the axis lines J6 and J7) and the second
Since the length of the link 11 is the same as the link length (between the axis lines J7 and J8), this allows straight-line conveyance. Further, at the time of this conveyance, the holding means 13 is also driven to rotate in synchronization with the conveyance device main body 12, so that the direction of the work W is the same when it is in one press machine 80 and the other press machine 81. Can be oriented. In this way, the work can be continuously conveyed by reciprocating bidirectionally from the one press 80 to the other press 81.

FIG. 2 is a vertical cross-sectional view showing the internal structure of the carrying device 1, and FIG. 3 is a first link 10 and a second link 11.
FIG. 14 is an enlarged cross-sectional view showing the vicinity of the connecting portion with FIG.
FIG. 3 is an enlarged cross-sectional view showing a connecting portion between the hand 7 of the robot 2 and the transfer device 1. The power transmission system of the carrier device 1 will be described with reference to these drawings.

The first driven rotation means 20 is built in the frame 25 of the first link 10. First driven rotation means 2
Reference numeral 0 denotes the shaft 26, the pair of first bevel gears 27 and 28 fixed to both ends of the shaft 26, and the first bevel gear 2
A pair of dish-shaped second bevel gears 29, 30 meshing with 7, 28
Have. The second bevel gear 29 on the base end side of the first link 20.
Is arranged coaxially with the sixth axis J6 of the robot and is fixed to the hand 7. A spur gear 33 is coaxially fixed to the second bevel gear 29 and is integrally fixed to the second bevel gear 29.

The shaft 26 is arranged on one side of the second bevel gear 29, and the servo motor 14 is arranged on the other side. The servomotor 14 is vertically arranged and fixed to the frame 25 so that its rotation axis is parallel to the sixth axis J6. A speed reducer 34 is provided below the servo motor 25. The speed reducer 34 decelerates the rotation of the rotation shaft of the servomotor 14 to rotate the spur gear 35, and the spur gear 35 meshes with the spur gear 33 integrally fixed to the second bevel gear 29.

The shaft 26 is disposed in the frame 25 along the first link 10 and is rotatably supported by the frame 25 by bearings 31 and 32 provided at both ends thereof. One of the first bevel gears 27 is the second
It meshes with the bevel gear 29.

At the tip of the first link 10, a seventh shaft J7 is attached.
A support shaft 40 having an axis as an axis is provided. The support shaft 40 is
The first link 10 is fixed to the upper wall of the tip portion of the frame 25, and projects downward along the seventh axis J7. A cylindrical body 41 is rotatably supported on the upper portion of the support shaft 40 via a bearing, and the second bevel gear 30 is fixed to the upper end of the cylindrical body 41. In this way, the second bevel gear 30
Is rotatably supported about the seventh axis J7. Also,
The frame 4 of the second link 11 is provided at the lower end of the cylindrical body 41.
2 is fixed, and the frame 42 of the second link 11 is supported by the lower end of the support shaft 40 protruding from the tip of the frame 25 via a bearing. That is, the second link 11 rotates integrally with the cylindrical body 41 and the bevel gear 30 around the seventh axis J7.

In the frame 42 of the second link 11, the second
The driven rotation means 21 is built in. Second driven rotation means 21
Has a structure similar to that of the above-mentioned first driven rotation means 20, and has a shaft 45, a pair of first bevel gears 46, 47 fixed to both ends of the shaft 45, and a first bevel gear 46 ,.
It has a pair of second bevel gears 48 and 49 that mesh with 47.
The lower half of the support shaft 40 is inserted into the frame 42 at the base end of the second link 11. A second bevel gear 48 is fixed to the support shaft 40, and one first bevel gear 46 meshes with the second bevel gear 48. At the tip of the second link 11, the other second bevel gear 49 is rotatably supported around the eighth shaft J8 as an axis, and the other bevel gear 47 of the shaft 45 is attached to the second bevel gear 49. Mesh. Second bevel gear 49
The holding means 13 is attached to, and integrally with the second bevel gear 49, the holding means 13 rotates about the eighth axis J8.

As described above, according to the present invention, since the rotation of the servo motor 14 is transmitted by using the shaft and the bevel gear to rotate the second link 11 and the holding means 13, as compared with a transmission system using a belt or the like. The rigidity can be increased.

The robot 2 moves the hand 7 straight along the transport path. At this time, the wrist 3 axes are rotated so that the hand 7 has a constant posture with respect to the installation surface (absolute coordinate system). The second bevel gear 29 and the spur gear 3 are attached to the hand 7.
3 is fixed. Therefore, when the spur gear 35 meshing with the spur gear 33 is rotationally driven by the servomotor 14, the spur gear 35 revolves around the spur gear 33. This spur gear 35 is the frame 25
Since the spur gear 35 revolves, the first link 10 rotates about the sixth axis J6.

The shaft 26 and the first bevel gears 27, 28 fixed to the shaft are rotatably supported by the frame 25. Moreover, since the dish-shaped second bevel gear 29 is fixed to the wrist, it does not rotate around the sixth axis J6. Therefore, the first bevel gear 27 that meshes with the second bevel gear 29
, While revolving around the sixth axis J6 together with the shaft 26, the shaft 26 rotates about its axis.

The first bevel gear 26 fixed to the tip of the shaft 26 meshes with the second bevel gear 30 provided at the tip of the first link 10. The second bevel gear 30 is supported rotatably around the seventh axis J7 with respect to the first link 11,
It is fixed to the frame 42 of the second link 11. Therefore, when the first bevel gear 28 rotates together with the shaft 26, the second link 11 rotates together with the second bevel gear 30 around the seventh axis J7.

When the first link 10 is rotated 180 ° from left to right in one conveyance, the second link 11 is rotated 360 °.
Rotate. That is, the number of teeth of the first bevel gears 27 and 28 and the second bevel gears 29 and 30 is selected so that the rotation of the first link 10 and the rotation of the second link 11 have a relationship of 1: 2.

The servomotor 14 for rotating the first link 10 with respect to the hand 7 decelerates via the decelerator 34 and then rotates the first link 10. Also, the shaft 26
Is a hollow structure, which is less prone to whirling than a shaft having the same cross-sectional area.

The number of teeth of the plate-shaped second bevel gear 29 on the base end side is larger than the number of teeth of the first gear 27 meshing with the second bevel gear 29.
That is, the rotation of the first link 10 is accelerated and the shaft 26
To rotate. Here, the number of teeth of the second bevel gear 29 is 48.
Since the number of teeth of the first bevel gear 27 is 6, the speed is increased by 8 times. Further, the number of teeth of the dish-shaped second bevel gear 30 meshing with the first bevel gear 28 on the tip side is larger than the number of the teeth of the first bevel gear 28. That is, the rotation of the shaft 26 is decelerated to rotate the second link 11. Here, since the number of teeth of the first bevel gear 28 is 9 and the number of teeth of the second bevel gear 30 is 36,
The speed is reduced to 1/4.

As described above, by increasing the speed in the front part of the shaft 26 and decelerating it in the rear part, the transmission torque of the shaft 26 can be suppressed to a small value, and the outer diameter of the shaft 26, in particular, the cross-sectional area is substantially increased. Can be made smaller. Thereby, it can be configured to be flat and lightweight. In addition, here, the speed is increased by 8 times in the front stage of the shaft 26 and 1 / in the rear stage.
Since the speed is reduced to 4, the second link rotates at twice the speed of the rotation of the first link 10. Further, with this configuration, the outer diameters of the first bevel gears 27 and 28 fixed to the shaft 26 can be reduced, and thus the first bevel gears 27 and 28 can be made flat.

The second driven rotation means 21 is provided in the frame 42 of the second link 11. The second bevel gear 48 provided at the base end of the second link 11 is fixed to the lower side of the support shaft 40 fixed to the tip of the first link 10, and the first bevel gear 46 fixed to the shaft 45 is The second bevel gear 4
8, the second link 11 rotates about the seventh axis J7, and the shaft 45 rotates about the axis.

The number of teeth of the first bevel gear 46 on the base end side of the second driven rotation means 21 is smaller than the number of teeth of the second bevel gear 48 meshing with the first bevel gear 46. Here, the number of teeth of the second bevel gear 48 is 27.
And the number of teeth of the first bevel gear 46 meshing with this is nine. Therefore, the shaft 45 of the second driven rotation means 21
In the previous stage, the speed is tripled.

The number of teeth of the first bevel gear 47 fixed to the tip of the shaft 45 is smaller than the number of teeth of the bevel gear 49 meshing with the first bevel gear 47. Here, the number of teeth of the first bevel gear 47 is 6, and the number of teeth of the second bevel gear 49 meshing with the first bevel gear 47 is 36. That is, the speed is reduced to 1/6 in the latter stage of the shaft. Here, since the speed is increased three times in the front stage of the shaft and decelerated to ⅙ in the rear stage, the holding means 13 rotates at a speed half that of the rotation of the second link 11.

As described above, the transmission torque of the shaft 45 can be reduced by increasing the speed in the front stage of the shaft 45 of the second driven rotation means 21 and decelerating it in the rear stage, and thus the diameter of the shaft 45 can be reduced. In particular, the cross-sectional area can be made substantially smaller, which allows flatness and light weight.

For example, when the first link 10 is rotated clockwise from left to right by 180 ° and conveyed, the second link 11 rotates counterclockwise by 360 °. Further, generally, in a transmission mechanism using a bevel gear, a pair of second bevel gears that mesh with a pair of first gears that are fixed to both ends of the shaft mesh with the first bevel gear from the same side with respect to the shaft. To do. When the first driven rotation means 20 of this embodiment is configured in this way, both the first link 10 and the second link 11 rotate in the same direction. Therefore, in the present embodiment, one second bevel gear 29 meshes with the shaft 26 from below, and the other second bevel gear 30 meshes with the shaft 26 from above. With this configuration, the rotation direction of the first link 10 and the second link 1
The rotation direction of 1 may be the opposite direction.

As described above, during the transportation, the first link 1
When 0 rotates 180 degrees clockwise from left to right, the second
The link 11 rotates 360 ° counterclockwise. Therefore, the work to be held can be conveyed non-inverted by rotating the holding means 13 by 180 ° clockwise during the conveyance.

At this time, since the rotation direction of the second link 11 and the rotation direction of the holding means 13 are opposite to each other, the pair of dish-shaped second bevel gears 4 in this second driven rotation means 21 is also reversed.
8, 49 are configured to mate from opposite sides with respect to shaft 45. Thereby, the rotation direction of the second link 11 and the rotation direction of the holder 13 can be reversed. When the second link 11 rotates 360 ° clockwise, the holder 13 rotates 180 ° clockwise.

In the prior art shown in FIG. 15, the surface pressure direction from the second bevel gear 103 to the first bevel gear 101 is the same as the surface pressure direction from the second bevel gear 104 to the first bevel gear 102. , The stress on the shaft 100 in the arrow P direction is
Since the surface pressure is doubled, a supporting member for countering the stress is required, friction loss occurs between the shaft 100 and the supporting member, and the rotational force transmission efficiency is reduced. Further, this structure has a problem that backlash is likely to occur.

On the other hand, in the configuration of the present invention, the surface pressure direction from the second bevel gear 29 to the first bevel gear 27 and the surface pressure direction from the second bevel gear 30 to the first bevel gear 28 are opposite. Since the surface pressure stresses cancel each other out and the above-mentioned problems do not occur,
Rotational force transmission efficiency does not drop and backlash does not easily occur.

As shown in FIG. 2, a load reducing means 15 is provided from the tip of the upper arm 5 of the robot 2 to the tip of the first link 10. The load reducing means 15 is
It has a cylinder 50, a piston rod 51 and a spring 52. A piston rod 52 is inserted in the cylinder 50, and the piston rod 52 and the cylinder 50 are connected via a compression coil spring 52 provided in the cylinder 50. Therefore, when the load reducing means 15 expands,
Apply force in the direction of contraction.

The base end of the cylinder 15 is rotatably attached to the end of the upper arm 5, and the piston rod 51
Is attached to the tip of the first link 10 in a freely rotatable manner.

At the time of transportation, the robot 2 causes the wrist to reciprocate linearly along the transportation path. Next, with reference to FIGS. 4 to 8, the operation of the robot during transportation will be described in more detail. FIG. 4 is a front view of the robot 2 during transportation, FIG. 5 is a plan view, and FIG. 6 is a side view. In each figure, A shows the state when the robot arms 4 and 5 are extended to one position A, which is one press machine, and B
Shows a state in which the arms 4 and 5 are folded at the central position B, and C shows a state in which the arms 4 and 5 are extended to the other position C which is the other press machine. In addition, FIG.
5 is a plan view and a front view showing an extended state of the transfer device 1 when the transfer device 5 is extended to the other position C. FIG. 8 is a folded state of the transfer device 1 when the arms 4 and 5 are folded at the central position B. FIG. 3 is a plan view and a side view showing FIG.

In the present embodiment, the work is conveyed from one press machine to the other press machine in a substantially straight line on the horizontal plane. That is, as shown in FIGS. 4 to 6, the movement path of the wrist 6 of the robot is substantially a straight line. In this embodiment, the movement distance W1 of the wrist 6 of the robot (see FIG. 4)
Is 5.4 m, the stroke W2 of the transport device 1 in the extended state (see FIG. 7) is 1.8 m, and the stroke W3 of the transport device 1 in the folded state (see FIG. 8) is 0.9 m.
And The work weight is 30 to 50 kg, and the weight of the holding means 13 is 30 kg. Moreover, the load reducing means 15 shall expand and contract within the range of 0.9 to 1.1 m.

The operation of the arms 4 and 5 of the robot during transfer will be described in more detail. When extended to one position A and the other position B, as shown in FIGS. 4 to 6, the lower arm 4 and the upper arm 5 are , Extends to one side close to horizontal. At the central position B, the lower arm 4 and the upper arm 5 are almost vertically raised and folded.

Further, the carrying device 1 is always horizontal at the time of carrying, and the arms 4, 5 are provided at one and the other positions A, C.
As shown in FIG. 7, the carrier device 1 also moves the first
When the link 10 and the second link 11 extend in a straight line and the arms 4 and 5 are folded at the central position B, the first link 10 and the second link 11 are folded together as shown in FIG. 8.

The load reducing means 15 is attached from the vicinity of the wrist 6 at the tip of the upper arm 5 to the tip of the first link 10 of the carrier 1. When in the central position B, as shown in FIG. 8, the upper arm 5 and the first link 10 are
The positional relationship is close to a right angle, and at this time, the load reducing means 1
The angle θ formed by 5 and the transfer device 1 is about 40 °, and the load reducing means 15 is in the extended state.

At one and the other positions A and C,
As shown in FIG. 7, since the upper arm 5 lays down to a nearly horizontal state, the angle θ formed by the load reducing means 15 and the transfer device 1 is about 30 °, and the load reducing means 15 is in an extended state. In the present embodiment, the stroke length L1 of the balancer in the contracted state shown in FIG. 8 is about 1.1 m, and the stroke length of the load reducing means 15 in the extended state shown in FIG. 7 is about 0.9 m.

As shown in FIG. 8, at the central position B, the carrying device 1 is folded and the work and the holding means 13 are arranged immediately below the wrist 6, so that the load applied to the wrist is minimized. On the other hand, at the one and the other positions A and C, the carrying device 1 extends and the holding means 13 and the work are arranged at the most distal end of the carrying device 1, so that the load applied to the wrist 6 becomes the largest.

As described above, the load reducing means 15 has the spring 52. When the load reducing means 15 is expanded, the spring 52 is compressed, and the spring force acts in the direction of contracting the load reducing means 15. That is, when moving to the one side and the other side, the load reducing means 15 acts in the direction of lifting the tip of the first link 10 upward, whereby the load of the wrist 6 is released to the upper arm 5, and the wrist is released. The load on 6 can be reduced. The load released to the upper arm 5 by the load reducing means 15 is so small that it does not cause any problem for the upper arm 5.

In this way, when the load on the wrist 6 of the robot 2 becomes large, this load can be reduced by the load reducing means 15. When the load applied to the wrist 6 is at the center position where the load is the smallest, the load reducing means 15 contracts and almost no spring force is generated. In this way, as the load on the wrist increases, the load reduction by the load reducing means 15 increases,
It is possible to suppress variations in the load applied to the wrist during a series of transfer operations.

Such a load reducing means is not limited to a spring as long as it exerts a force in a contracting direction when it expands, and may use hydraulic pressure or pneumatic pressure.

Further, as shown in FIG. 2, since the support shaft 40 has a hollow structure, a work suction air hose or the like can be inserted therethrough and interference with the movement of the link can be eliminated.

In the above-mentioned embodiment, the pair of second bevel gears are arranged on the opposite side to the shaft, but the present invention is not limited to this, and as shown in FIG. 9, the second bevel gears are arranged on the same side. It may be placed at. In the example shown in FIG. 9, the pair of second bevel gears 28 and 29 is arranged below the shaft 26 in the first driven rotation means 20, and the pair of second bevel gears 48 is also arranged in the second driven rotation means 21. , 49 are arranged below the shaft 45. However, when the second bevel gears are arranged on the same side with respect to the shaft, the rotation directions become opposite. Therefore, in order to match the rotation directions, the first and second driven rotation means 2
Idle gears 60 and 61 were respectively interposed between 0 and 21 to match the rotation directions.

By thus disposing the pair of second bevel gears on the same side with respect to the shaft, it becomes possible to make the conveying device 1 flatter.

Further, in the above-described embodiment, the servo motor 14 is mounted so that the rotation axis thereof is parallel to the sixth axis, that is, vertical, but the present invention is not limited to such a configuration, and as shown in FIG. In addition, the output shaft of the servo motor 14 may be arranged parallel to the shaft 26, that is, horizontally. In this case, the reduction gear 34 is provided with a bevel gear 65, and the bevel gear 65 is meshed with the second bevel gear 29.

By horizontally placing the motor 14 in this manner, the spur gear 33 is unnecessary, the number of parts can be reduced, and the entire link mechanism can be made compact.

In the above-described embodiment, the robot 2
In which the hand 7 has a constant posture with respect to the installation surface (absolute coordinate system) and the entire transport device 1 is rotated around the sixth axis J6, the present invention is not limited to this, and the robot 2
The hand 7 may directly rotate the first link 10 and the servomotor 14 may rotate the second link. 11 is a cross-sectional view showing the structure of the carrier device 70 for directly rotating the first link 10 with the hand 7, and FIG.
It is sectional drawing which expands and shows the connection part of the hand 7 of a robot, and the conveyance apparatus 70. As shown in FIG.

In this carrying device 70, the hand 7 of the robot 2 is fixed to the frame 25 of the first link 10, and the hand 7 rotates the first link 10 around the sixth axis J6. The second bevel gear 29 arranged below the hand 7 is rotatably supported by the frame 25 about the sixth axis J6. Therefore, the second bevel gear 29 is the servo motor 1
By rotating by 4, the second link 11 rotates via the shaft 26. That is, the first driven rotation means 26 transmits the rotational force of the servo motor 14 arranged at the base end portion of the first link 10 to the tip end, and the second link 1
Rotate 1.

The second driven rotation means 21 further transmits the rotation of the servomotor 14 to the holding means 13 at the tip of the second link 11.

As described above, by directly rotating the first link 10 by the hand 7 of the robot and rotating the second link 11 by the servo motor 14, the transfer device 70 can be efficiently driven.

In the present embodiment, both the first link 10 and the second link 11 are driven by the shaft drive, but the conventional belt drive system or the gear train drive system may be used together. That is, the first link 10 is a gear train, the second link 11 is a shaft drive of the present invention, or the first link 10 is a shaft drive.
The second link 11 may be driven by a belt or the like.

[0088]

As described above, according to the present invention, since the driven rotation means is composed of the shaft and the bevel gear, the drive system can have a high rigidity as compared with the transmission of the belt or the like. In addition, the transmission between the shaft and the bevel gear makes it possible to have a flat and compact structure as compared with the transmission through the belt and the pulley. Further, even if the link length is increased as compared with the transmission by the gear train, it is not necessary to increase the diameter of the gear, so the width can be reduced, and the number of parts is small, so that the weight can be reduced. In this way, by making the drive system lightweight and having high rigidity, it is possible to increase the conveying speed and further extend the conveying distance. Moreover, since it is flat, it is suitable for conveyance between presses.

Further, according to the present invention, by arranging the drive source laterally, it is possible to make the entire conveying device compact. Further, according to the present invention, the load on the robot can be reduced by providing the load reducing means using a spring or the like. As a result, the transportable weight can be increased.

Further, according to the present invention, since the intersection of the axis line of the second bevel gear and the axis line of the shaft is on the extension of the shaft axis line to the outside, as compared with the conventional configuration shown in FIG.
The driven rotation means can be made thin, and the carrier device itself can be made flat.

Further, according to the present invention, the second bevel gears that mesh with both ends of the shaft are configured to mesh with each other from opposite sides with respect to the shaft, so that the structure is simple and the first link and the second link are connected. It is possible to rotate and in opposite directions.

Further, according to the present invention, the second bevel gear meshing with both ends of the shaft is meshed with the shaft from the same side in order to effectively utilize the space inside the frame in which the shaft is contained, and the driven gear is driven. By providing one gear in order to reverse the rotation direction and match the rotation direction, the driven rotation means can be made even flatter.

Further, according to the present invention, since the speed increasing mechanism is provided in the front stage of the driven rotation means and the speed reducing mechanism is provided in the rear stage, it becomes possible to suppress the transmission torque of the shaft portion to a low level. The diameter can be reduced,
It can be made lighter.

Further, according to the present invention, it is possible to convey the conveyed object in a non-inverted manner.

[Brief description of drawings]

FIG. 1 is a diagram showing a transfer system using a transfer device 1 according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structure of a carrier device 1.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of a connecting portion between a first link 10 and a second link 11.

FIG. 4 is a front view showing the operation of the robot 2 during transportation.

FIG. 5 is a plan view showing an operation of the robot 2 during transportation.

FIG. 6 is a side view showing the operation of the robot 2 during transportation.

7A and 7B are a plan view and a front view showing a state in which the carrier device 1 is extended.

8A and 8B are a plan view and a front view showing a state in which the carrying device 1 is folded.

FIG. 9 is a view showing a conveying device of a type in which a pair of second bevel gears is provided opposite to a shaft.

FIG. 10 is a diagram showing a structure of a conveyance device in which a servo motor 14 is laterally oriented.

FIG. 11 is a diagram of a transfer device of a type in which the wrist 6 of the robot 2 rotates the first link 10.

FIG. 12 is a diagram illustrating a transport operation of the transport device 1.

13 is an enlarged cross-sectional view showing a connecting portion between the hand 7 of the robot 2 and the transfer device 1. FIG.

FIG. 14 is an enlarged cross-sectional view showing a connecting portion between the hand 7 of the robot 2 and the transfer device 70.

FIG. 15 is a diagram showing a configuration of a conventional driven rotation means.

[Explanation of symbols]

1 Conveyor 2 robots 4 Lower arm 5 Upper arm 6 wrists 7 Minions 10 First link 11 Second Link 12 Transport device body 13 Holding means 20 First driven rotation means 21 Second driven rotation means 26,45 shaft 27, 28, 46, 47 1st bevel gear 29, 30, 48, 49 2nd bevel gear

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B25J 1/00-21/02

Claims (10)

(57) [Claims] 1. A transfer device, which is attached to a wrist of a robot and which moves a holding means for holding an object to be transferred bidirectionally in synchronization with a reciprocating motion of the robot, to perform a straight transfer of the object to be transferred. Part is attached to the wrist of the robot, the holding means is attached to the tip part, and the link mechanism that expands and contracts bidirectionally in synchronization with the reciprocating motion of the robot and the base part of the link mechanism are provided to drive the link mechanism. And a driven rotation unit that is provided in the link mechanism and that drives the link to rotate based on the rotational power of the drive source by using a shaft and a bevel gear. A carrier device, which is arranged in parallel. 2. A transfer device, which is attached to a wrist of a robot and which moves a holding means for holding an object to be transferred bidirectionally in synchronization with the reciprocating motion of the robot, to carry the object directly in a straight line. Part is attached to the wrist of the robot, the holding means is attached to the tip part, and the link mechanism that expands and contracts bidirectionally in synchronization with the reciprocating motion of the robot and the base part of the link mechanism are provided to drive the link mechanism. A driving source, and a driven mechanism, which is provided in the link mechanism and drives the link to rotate based on the rotational power of the driving source using a shaft and a bevel gear, and one end of which is attached to the arm of the robot. The other end is attached to a link mechanism, and a load reducing means for reducing a load applied to a wrist of the robot by applying a force in a contracting direction is provided. Feeding apparatus. 3. The driven rotation means has a first bevel gear fixed to both ends of a shaft, and a second bevel gear meshing with the first bevel gear, and the first bevel gear is The second bevel gear is meshed with the shaft from the outside of the shaft, and the intersection of the axis of the second bevel gear and the shaft of the shaft is on the extension of the shaft of the shaft to the outside. Alternatively, the transport device according to item 2. 4. The driven rotation means has a pair of first bevel gears fixed to both ends of the shaft, and a pair of second bevel gears meshing with the first bevel gear, A second bevel gear that meshes with one end and a second bevel gear that meshes with the other end
The bevel gear of claim 1 meshes with the shaft line of the shaft from mutually opposite sides.
The transport device described in 1. 5. The driven rotation means matches a driven rotation direction with a pair of first bevel gears fixed to both ends of a shaft and a pair of second bevel gears meshing with the first bevel gear. A second bevel gear that meshes with one end of the shaft and a second bevel gear that meshes with the other end of the shaft mesh with each other from the same side with respect to the axis of the shaft. The transport device according to any one of claims 1 to 3. 6. The transfer device according to claim 1, wherein a speed increasing mechanism is provided in a front stage of the driven rotation means, and a speed reducing mechanism is provided in a rear stage of the driven rotation means. 7. The driven rotating means is characterized in that the holding means attached to the tip of the link mechanism is driven to rotate based on the rotation of the link, and the conveyed object is conveyed while keeping the posture of the conveyed object constant. The transport device according to any one of claims 1 to 6. 8. The robot is mounted on the wrist of the robot, and in parallel with the reciprocating motion of the robot, a holding means for holding the transported object is moved in both directions to carry the linearly transported object, the base end portion of which is the robot. Attached to the wrist of the robot, the holding means is attached to the distal end of the link mechanism, and the link mechanism expands and contracts bidirectionally in synchronization with the reciprocating movement of the robot; and the drive mechanism that is provided at the base end of the link mechanism and drives the link mechanism. And a driven rotation means provided in the link mechanism and driven to rotate the link based on the rotational power of the drive source using a shaft and a bevel gear, wherein the driven rotation means is the tip portion of the link mechanism. The holding means attached to is driven to rotate based on the rotation of the link,
In a transfer device that transfers an object to be transferred at a constant posture during transfer, a link mechanism is attached to a wrist of a robot, and has a first link having the base end portion, and a tip of the first link around an axis. A second link that is rotatably connected and that has the tip end portion to which the holding means is attached; the driven rotation means that is included in the first link and the second driven link that is included in the first link. And a second driven rotation means, wherein the first driven rotation means is fixed to one end which is the base end of the first shaft and the other end which is the tip of the first link. The first bevel gear has a first bevel gear and a second bevel gear that meshes with the first bevel gear. The first bevel gear meshes with the second bevel gear from the outside of the first shaft to provide the second bevel gear. The intersection of the axis line of the bevel gear and the axis line of the first shaft is the axis line of the first shaft. The third driven umbrella is fixed to one end of the second shaft which is the tip side of the first link and the other end which is the tip of the first link. The third bevel gear includes a gear and a fourth bevel gear that meshes with the third bevel gear. The third bevel gear meshes with the fourth bevel gear from the outside of the second shaft to provide a fourth bevel gear. The intersection of the axis and the axis of the second shaft is on the extension of the axis of the second shaft to the outside, and the first end of the one end of the first shaft of the first driven rotation means is provided.
And a second bevel gear to increase the speed, and the first and second bevel gears at the other end of the first shaft to reduce the speed, and the third end to the third end of the second shaft of the second driven rotation means.
And a fourth bevel gear, and the deceleration is performed by the third and fourth bevel gears at the other end of the second shaft. 9. The pair of second bevel gears of the first driven rotation means are arranged such that the first bevel gears are first from opposite sides with respect to the axis of the first shaft.
9. The conveyance device according to claim 8, wherein the bevel gear meshes with each of the pair of fourth bevel gears of the second driven rotation means, and the fourth bevel gears mesh with the third bevel gear from opposite sides with respect to the axis of the second shaft. . 10. The first driven rotation means has a fifth gear for matching the driven rotation direction, and the pair of second bevel gears of the first driven rotation means are the same with respect to the axis of the first shaft. From the side, the second driven rotation means has a sixth gear for matching the driven rotation direction, and each of the pair of fourth bevel gears of the second driven rotation means has a second gear. The transport device according to claim 8, wherein the third bevel gear meshes with the shaft line of the shaft from the same side.