JP6962118B2 - Work transfer device - Google Patents

Description

The present disclosure relates to a work transfer device that transfers a work between a plurality of work facilities.

Conventionally, in addition to the work equipment such as machine tools or inspection equipment that composes the production line, a work is set in each work equipment, and a work transfer device for transporting the finished work to the next work equipment is provided in the work. On the other hand, a production system that executes a series of work processes in order is known. For example, Patent Document 1 includes a traveling rail laid along a plurality of machine tools and a dual-arm robot having a robot arm having a scalar structure. The configuration for delivering the work between the two is described. In this configuration, the dual-arm robot is arranged above the traveling rail laid on the floor, and the weight of the dual-arm robot is supported by the traveling rail.

Japanese Unexamined Patent Publication No. 2005-46966

By the way, in the device described in Patent Document 1, the traveling rail has a configuration in which the traveling rail has a horizontal spread in a cross section perpendicular to the traveling direction of the dual-arm robot, and when an operator approaches the machine tool for the purpose of maintenance or the like. In addition, there was a concern that the traveling rail would become an obstacle and workability would be reduced. Therefore, a configuration has been studied in which a plurality of rails are arranged side by side in the vertical direction and these rails support a transfer unit such as a dual-arm robot.

However, in such a configuration, when viewed from the traveling direction of the transport unit, a moment of force that causes the transport unit to collapse around the rail is generated, and a large load acts on the connecting portion between the transport unit and the rail. There was something. For example, when the robot of the transport unit extends the arm toward the work equipment and the work is gripped by the tip of the arm, a large load tends to be generated. If the rail is twisted or the transfer unit is misaligned due to such a load, for example, there is a concern that the positioning accuracy of the work in the work of delivering the work may be lowered.

Therefore, an object of the present technology is to provide a work transfer device capable of reducing the load acting on the connecting portion between the transfer unit and the rail.

One aspect of the present technology is a work transfer device that transfers a work between a plurality of work facilities.
A first rail extending along the first horizontal direction in which the plurality of work facilities are lined up, and
Said extends parallel to the first rail, a second rail disposed alongside said first rail below the first rail,
A robot supported by the first rail and the second rail and moving along the first direction, and a robot supported by the moving body that grips a work and delivers it between the plurality of work facilities. And a transport unit including a control device supported by the moving body and controlling the operation of the robot.
The robot is arranged at a position above the first rail and the second rail and overlapping the first rail with respect to a second direction orthogonal to the first direction when viewed from above.
The control device is on the opposite side of the plurality of work facilities with respect to the first rail and the second rail in the second direction, and the first rail as viewed from the second direction in the vertical direction. And is arranged at a position overlapping with at least one of the second rails.

According to the work transfer device according to the present technology, it is possible to reduce the load acting on the connecting portion between the transfer unit and the rail.

(A) and (b) are both perspective views of the work transfer device according to the present embodiment. (A) is a plan view of the work transfer device, and (b) is a side view of the work transfer device as viewed from the opposite side of the work equipment. FIG. 2 is a cross-sectional view of the work transfer device at the position shown in FIG. 2 (b). (A) and (b) are both perspective views of the transport loader. (A) is a plan view of the transfer loader, (b) is a side view of the transfer loader as viewed from the opposite side of the work equipment, and (c) and (d) are side views of the transfer loader as viewed from the traveling direction of the guide rail. (A) is a side view showing a robot arm in a detachable posture, and (b) is a side view showing a robot arm in a running posture. (A) and (b) are views showing the position of the center of gravity in the first configuration example of the transfer loader, and (c) and (d) are side views showing the position of the center of gravity in the second configuration example of the transfer loader, (e). , (F) are side views showing the position of the center of gravity in the third configuration example of the transport loader.

Hereinafter, the work transfer device according to the present disclosure will be described with reference to the drawings. This work transfer device can be suitably used for a general production system in which a work is sequentially delivered between a plurality of work facilities including a production line for automobile parts and the work is performed on the work according to a work process.

As shown in FIGS. 1A and 1B, the work transfer device 1 includes one or a plurality of transfer loaders 2 provided with a robot arm 5, and a guide rail 3 serving as a travel path for the transfer loader 2. , Equipped with. The transfer loader 2, which is an example of a transfer unit that transfers a work between a plurality of work facilities, sets the work in the work facility arranged in the space on one side of the guide rail 3 (the left side in FIG. 1A). , The work is grasped and moved along the guide rail 3, and the operation of setting the work in the work equipment responsible for the next process is repeated.

In this embodiment, the content of the work performed in each work facility is not particularly limited, and in addition to a machine tool that performs processing such as pressing, welding, and polishing, a device for assembling a plurality of works, a machine, or a human being can be used. It may be a facility for inspecting a work. Further, the transfer loader 2 may have a function of transferring the work between the work equipments. For example, the transfer loader 2 itself has a function of performing some work on the work by using the robot arm 5. You may.

Hereinafter, the vertical direction will be the Z-axis direction, the traveling direction of the transport loader 2 will be the X-axis direction in a plane perpendicular to the Z-axis direction, and the Z-axis and the direction perpendicular to the X-axis will be described as the Y-axis direction. FIG. 2A is a plan view of the work transfer device 1, and FIG. 2B is a side view of the work transfer device 1 as viewed from the opposite side of the work equipment in the Y-axis direction. The guide rail 3 of the work transfer device 1 is configured by connecting a plurality of rail units 31, 32, 33 in the X-axis direction. A plurality of types of rail units 31, 32, and 33 having different lengths d1, d2, and d3 in the X-axis direction are prepared, and the combination can be appropriately changed and used according to the arrangement of the work equipment. It is configured.

Each rail unit 31 to 33 includes an upper rail 3a and a lower rail 3b, and a trolley wire 3c located between the upper and lower rails 3a and 3b. The upper rail 3a corresponds to the first rail extending in the first direction (X-axis direction of the present embodiment) in which a plurality of work facilities are lined up, and the lower rail 3b is arranged below the first rail and parallel to the first rail. Corresponds to the extending second rail.

As shown in the cross-sectional view of FIG. 3, the upper rail 3a and the lower rail 3b are arranged side by side in the Z-axis direction, and the legs 3e are fixed to the guide frame 3d supported on the floor surface. The trolley wire 3c corresponding to the feeder is composed of a plurality of electric wires extending in the X-axis direction while the lower side is covered with an open cover 3f, and each electric wire is connected to a power source or a communication device (not shown). ing. That is, the trolley line 3c according to the present embodiment includes a signal line for transmitting a signal from the communication device, and can transmit, for example, a command for urgently stopping the transport loader 2.

As shown in FIGS. 4A and 4B, the transport loader 2 includes a carriage 4 supported by a guide rail 3, a robot arm 5 supported by the carriage 4, and a control unit 8 attached to the carriage 4. And have. The trolley 4 corresponds to a moving body that can move along the upper rail 3a and the lower rail 3b, and the robot arm 5 corresponds to a robot that is supported by the moving body and transfers work to and from the work equipment. Although the robot arm 5 in this embodiment is an articulated robot, a robot having a scalar structure or a parallel link robot may be used.

The configuration of the transfer loader 2 will be described in detail with reference to FIGS. 5A to 5D. The carriage 4 has a frame body 40 that supports the weights of the robot arm 5 and the control unit 8, and a traveling wheel (not shown) that meshes with the upper rail 3a and the lower rail 3b, and is connected to the guide rail 3. 42 and. The frame body 40 has a horizontal frame 40a extending in the Y-axis direction above the upper rail 3a, and a vertical frame 40b extending in the Z-axis direction on the opposite side of the work equipment in the Y-axis direction with respect to the guide rail 3.

In the robot arm 5, the first arm 51, the second arm 52, and the third arm 53 are connected in order with the base 50 supported by the trolley 4 as a base, and the work is gripped at the tip of the third arm 53 in parallel. A wrist portion 55 to which a grip portion such as an arm or a claw-shaped chuck is attached is provided. The robot arm 5 is driven with a drive degree of freedom of 6 axes by operating an actuator such as a built-in servomotor or a solenoid valve, and the work gripped by the grip portion can be moved to an arbitrary position and posture. Further, by replacing the grip portion according to the work to be conveyed, it is possible to adapt to the conditions such as the shape and weight of the work and the required positioning accuracy.

The control unit 8 corresponding to the control device is configured by storing the control panel 8a, which is the main body of the control device, in the protective housing 8b, and is attached to the frame body 40. The transfer loader 2 is provided with a current collector 13 that takes in current from the trolley wire 3c, and the control panel 8a controls the operation of each part of the transfer loader 2 by using the electric power supplied through the current collector 13. The control panel 8a is provided with a control circuit including a computing device and a memory, and by executing a pre-installed program, the actuator of the robot arm 5 and the traveling wheel of the trolley 4 are driven by using the current taken from the trolley wire 3c. It drives the driving motor to control the operation of the robot arm 5 and the traveling operation of the transfer loader 2.

In addition, the transfer loader 2 relays the wiring connecting the protective plate 11, the control unit 8, and the robot arm 5 that protect the front surface (the surface facing the work equipment) of the transfer loader 2 above the guide rail 3. A device such as a compressor that supplies compressed air to the terminal box 9 that houses the substrate and the robot arm 5 is mounted as needed. Further, the control unit 8 is connected to another transport loader supported by the guide rail 3 or a control center that controls the production line by wire or wirelessly so as to cooperate between a plurality of transport loaders and the production line. It is configured in.

Here, the arrangement of the rails and the weight balance of the transport loader 2 will be described. In this embodiment, the transfer loader 2 is supported by a plurality of rails 3a and 3b arranged vertically, and the robot arm 5 located above the rails 3a and 3b transfers the work to and from the work equipment. ing. With such a configuration, the occupied area of the guide rails viewed from above is smaller than that of the arrangement in which a plurality of rails are arranged horizontally, and the operator can easily access the work equipment. That is, since it is easy for the worker to approach the work equipment from the lower side in FIG. 2A, workability in work such as inspection of the work equipment and replacement of parts is improved.

However, under such an arrangement of rails arranged vertically, a moment that causes the transfer loader 2 to be tilted may be generated due to a deviation between the position of the rail and the position of the center of gravity of the transfer loader 2. For example, in FIG. 3, when the rail is arranged as close to the work equipment as possible in the Y-axis direction (see the broken line P0), the weight of the robot arm 5 attempts to rotate the trolley 4 in the clockwise direction in the drawing. A moment of force is generated. If the position of the robot arm 5 is displaced due to such a moment, there is a concern that the accuracy of the work delivered to the work equipment may be reduced. On the other hand, for example, increasing the rigidity of the guide rail 3 to the extent that the influence of the moment can be ignored leads to an increase in size and cost of the guide rail 3.

Further, in the conventional work transfer device, a control device such as a control panel 8a for controlling the operation of the robot arm 5 is arranged separately from the transfer loader 2, and a configuration is used in which a control signal is sent to the transfer loader 2 by a wired connection. Was there. However, in such a configuration, the configuration of the production system is complicated by the wiring connecting the transport loader 2 and the control device, and the accessibility of the worker to the work equipment is lowered.

Therefore, in the work transfer device 1 according to the present embodiment, the arrangement of the guide rail 3 is offset so that the robot arm 5 supported by the carriage 4 is located above the upper rail 3a, and the control unit 8 is attached to the carriage 4. Adopted the configuration to be installed.

That is, as shown in FIG. 3, the connection position P1 between the upper and lower rails 3a and 3b and the connection portions 41 and 42 of the transfer loader 2 is separated from the frontmost surface of the work equipment in the second direction (Y-axis direction). The robot arm 5 and at least the upper rail 3a overlap each other when viewed from above. In other words, the direction in which the connection position P1 of the guide rail 3 and the transfer loader 2 is separated from the work equipment as compared with the position of the protective plate 11 (broken line P0) forming the side surface of the transfer loader 2 on the work equipment side in the Y-axis direction. It was offset (to the right in the figure). More specifically, it is preferable that the base 50 of the robot arm 5 is arranged so as to overlap each of the upper rail 3a and the lower rail 3b when viewed from above. With such an arrangement, the position of the center of gravity of the robot arm 5 in the Y-axis direction approaches the position of the upper rail 3a, so that it is possible to reduce the generation of a force moment that causes the robot arm 5 to fall in the clockwise direction in the drawing. can.

Further, the control unit 8 is supported by the carriage 4 and is arranged at a position where it overlaps with at least one of the upper rail 3a and the lower rail 3b in the Z-axis direction and on the opposite side of the work equipment in the Y-axis direction with respect to the guide rail 3. bottom. By configuring the control unit 8 as a part of the transfer loader 2, the wiring constituting the work transfer device 1 can be minimized. Then, by arranging the control unit 8 having a certain weight on the side of the guide rail 3 and arranging the positions of at least one of the rails 3a and 3b in the vertical direction to overlap with each other, the position of the center of gravity of the transfer loader 2 is possible. It can be set as low as possible to improve the stability of the transport loader 2.

Here, as shown in FIG. 6A, when the transport loader 2 sets (mounts) or removes the work from the work equipment, the robot arm 5 extends in the Y-axis direction toward the work equipment. Take a posture (detachable posture). At this time, the distance X1 from the connecting portions 41 and 42 of the transport loader 2 to the guide rail 3 to the center of gravity position Ga of the transport loader 2 is the center of gravity position Gb when the transport loader 2 travels between the work facilities (FIG. 6 (b)). ) Is smaller than the distance X2. In other words, the offset amount X0 of the connecting portions 41 and 42 in the Y-axis direction is set so that the center of gravity position Ga of the transport loader 2 approaches the positions of the connecting portions 41 and 42 when the robot arm 5 takes the detachable posture. Has been done. However, the offset amount X0 is the distance from the end position of the carriage 4 on the work equipment side (for example, the position of the protective plate 11 in FIG. 3) to the connecting portions 41 and 42.

In such a configuration, by arranging the control unit 8 on the opposite side of the work equipment in the Y-axis direction, the weight balance in the state where the robot arm 5 extends toward the work equipment becomes good. That is, when the connecting portion 41 between the upper rail 3a and the transfer loader 2 is considered as a fulcrum in a state where the robot arm 5 is in the detachable posture, the weight of the robot arm 5 and the work W gripped by the connecting portion 41 causes the transfer loader 2 to be attached. The moment of the acting force and the moment of the force acting on the transfer loader 2 due to the weight of the control unit 8 cancel each other out. Therefore, it is possible to avoid applying a large load to the connecting portion between the guide rail 3 and the transport loader 2.

In the configuration in which the control unit 8 is arranged on the same side as the work equipment in the Y-axis direction, when the robot arm 5 extends the arm toward the work equipment, a large moment in the direction of falling toward the work equipment is generated. It ends up. Further, when the control unit 8 is arranged above the guide rail 3, the position of the center of gravity of the entire transfer loader 2 rises and the stability is impaired, and when the control unit 8 is arranged below the guide rail 3, the guide rail 3 moves. The height of the work transfer device 1 increases by the amount of the space provided. Therefore, by adopting the arrangement of the present embodiment, the weight balance of the transport loader 2 becomes good while avoiding such inconvenience.

Next, the posture (running posture) of the robot arm 5 when the transport loader 2 travels while holding the work W from a position facing a certain work equipment to a position facing another work equipment will be described. As shown in FIG. 6B, in the traveling posture, the robot arm 5 and the work W gripped by the tip thereof are held above the connecting portions 41 and 42 with respect to the guide rail 3. In other words, when the transport loader 2 travels between a plurality of positions facing a plurality of work facilities, the control unit 8 has an upper rail when the arms (51 to 53) of the robot arm 5 and the work W are viewed from above. The posture of the robot arm 5 is controlled so as to be held at a position overlapping with 3a. As a result, it is guaranteed that the center of gravity position Gb of the transfer loader 2 including the work W when the transfer loader 2 travels is near the connection position of the transfer loader 2 and the guide rail 3 regardless of the weight of the work W. Will be done.

If a configuration is adopted in which the robot arm 5 is tilted in a direction away from the work equipment (to the right in the figure) when the transport loader 2 travels to avoid interference with the work equipment, the robot arm 5 A part of the protrusion may protrude toward the right side in the drawing, and the protruding portion may come into contact with an obstacle as the transport loader 2 travels. Further, in order to keep the center of gravity position Gb of the transfer loader 2 near the connection position of the transfer loader 2 and the guide rail 3 regardless of the weight of the work W, the inclination angle of the robot arm 5 is changed according to the weight of the work W. It is necessary to do so, and the control becomes complicated. On the other hand, if the running posture as in the present embodiment is taken, such inconvenience can be avoided.

FIG. 7 shows the results of analyzing the positions of the centers of gravity of the three transfer loaders 2 having different configurations. In FIG. 7, (a) and (b) represent the first configuration example (2A) of the transport loader 2, and (c) and (d) represent the second configuration example (2B) of the transport loader 2. (E) and (f) represent a third configuration example (2C) of the transfer loader 2. Further, each upper view is a schematic view seen from the Y-axis direction, and each lower figure is a schematic view of a cross section seen from the X-axis direction. The center-of-gravity positions G1, G2, and G3 in each figure represent the positions of the center of gravity of the transfer loaders 2A, 2B, and 2C when the robot arm 5 does not grip the work and is in the traveling posture.

The transfer loaders 2A to 2C shown in each figure of FIG. 7 differ in the positional relationship of the elements constituting the transfer loaders 2A to 2C, such as the arrangement of the control unit 8 and the terminal box 9 in the vertical direction being different. The center of gravity positions G1 to G3 are also different. For example, the central position of the connecting portions 41 and 41 between the carriage 4 and the upper rail 3a is set as the reference position Px in the X-axis direction, and the position of the upper rail 3a viewed from the X-axis direction is the reference position in the Y-axis direction and the Z-axis direction. When Py and Pz are used, the center of gravity position G1 in the first configuration example is located at (-6 [mm], -187 [mm], +87 [mm]) from the reference point (Px, Py, Pz). .. The center of gravity position G2 in the second configuration example is located at a position (+37 [mm], -249 [mm], +328 [mm]) from the reference point (Px, Py, Pz). The center of gravity position G3 in the third configuration example is located at a position (+37 [mm], -249 [mm], +105 [mm]) from the reference point (Px, Py, Pz).

All of these configuration examples are examples of configurations in which the robot arm 5 and the control unit 8 are arranged as described in the above-described embodiment, and the load acting on the connecting portion with the guide rail 3 is practically sufficient. It is within a small value. For example, the control unit 8 in the second configuration example has a configuration that overlaps only the upper rail 3a in the Z-axis direction, and although the center of gravity position G2 is higher than in the other configuration examples, it acts on the guide rail 3. The magnitude of the load was within the permissible range.

In the configuration example shown in FIG. 7, the total weight of the transfer loader 2 is about 340 kg, of which the robot arm 5 occupies about 30 kg and the control unit 8 occupies about 50 kg. Further, the size of the transport loader 2 excluding the robot arm 5 in each configuration example is such that the length Lx in the X-axis direction is about 810 mm and the length Ly in the Y-axis direction is about 520 mm. Therefore, if the moment of the force acting on the transfer loader 2 centering on the upper rail 3a is within the same value as the moment of the force derived from these numerical values, the size, weight, etc. of the transfer loader 2 may be adjusted. Regardless of the details, it is possible to realize a weight balance as good as each configuration example shown in FIG.

[Other Embodiments]
In the present embodiment, the "first rail" and the "second rail" refer to any two rails when a plurality of rails are arranged at different positions in the vertical direction, and the guide rail 3 The present technology can also be applied to a form composed of three or more rails. Further, the first rail and the second rail are not limited to the positional relationship in which they overlap when viewed from above, and one of them may be offset from the other.

<Summary of this embodiment>
The work transfer device (1) according to the present embodiment is a work transfer device (1) that transfers a work between a plurality of work facilities.
A first rail (3a) extending along a first direction in which the plurality of work facilities are lined up, and
A second rail (3b) extending parallel to the first rail (3a) and arranged below the first rail (3a).
A moving body (4) supported by the first rail (3a) and the second rail (3b) and moving along the first direction, and a moving body (4) supported by the moving body (4) to grip the work. A transport unit (8) including a robot (5) that is transferred between the plurality of work facilities and a control device (8) that is supported by the moving body (4) and controls the operation of the robot (5). 2) and,
The first rail (5) is above the first rail (3a) and the second rail (3b) and is orthogonal to the first direction when viewed from above. It is placed at a position that overlaps with 3a),
The control device (8) is on the opposite side of the plurality of work facilities with respect to the first rail (3a) and the second rail (3b) in the second direction, and is in the second direction in the vertical direction. It is arranged at a position where it overlaps with at least one of the first rail (3a) and the second rail (3b) when viewed from the viewpoint.

With such an arrangement, the weight of the robot is supported by the first rail arranged at a position overlapping the robot when viewed from above, and the weight of the robot is prevented from acting as a force to cause the transport unit to collapse. Is done. Further, by arranging the control device on the opposite side of the work equipment at a position where it overlaps with at least one of the first rail and the second rail in the vertical direction, the weight of the control device causes the transport unit to collapse. It can be used to reduce the action as a force, and rather to maintain a good weight balance when the robot holds the work inside the work equipment.

Further, the work transfer device (1) according to the present embodiment is
It has a feeder line (3c) extending in the first direction between the first rail (3a) and the second rail (3b) in the vertical direction and connected to a power source.
The transport unit (2) includes a current collector (13) that takes in current from the feeder line (3c).

According to this configuration, since the power supply line is arranged using the space between the first rail and the second rail, the wiring for supplying electric power to the transfer unit becomes unnecessary, and the wiring constituting the work transfer device is minimized. It can be suppressed to the limit.

Further, in the work transfer device (1) according to the present embodiment,
The first rail (3a) and the second rail (3b) are arranged so as to overlap each other when viewed from above.

According to this configuration, the occupied area of the first rail and the second rail when viewed from above is minimized, so that the worker can easily access the work equipment in a situation such as maintenance work.

Further, in the work transfer device (1) according to the present embodiment,
The robot (5) is movably supported by a base (50) attached to the moving body (4) and an arm (51, 52, 53) that is movably supported by the base (50) and grips a work at a tip portion. And have
The base (50) is arranged so as to overlap the first rail (3a) when viewed from above.

According to this configuration, in a configuration in which the robot arm moves according to the work content, at least the base attached to the moving body exists at a position overlapping the first rail when viewed from above, so that the position of the center of gravity of the robot is located. Can be easily realized in a configuration that is well supported by the first rail.

Further, in the work transfer device (1) according to the present embodiment,
The transport unit (2) is located at a position where the arm (51, 52, 53) and the work (W) gripped by the arm (51, 52, 53) overlap the first rail (3a) when viewed from above. It is configured to move between a plurality of positions facing the plurality of work facilities while being held by the device.

According to this configuration, the weight balance when the transfer unit moves between a plurality of work facilities is well maintained, and the possibility that the arm of the robot or the work held by the arm interferes with an obstacle is reduced. be able to.

1 ... Work transfer device / 2 ... Transfer unit (convey loader) / 3a ... 1st rail (upper rail) / 3b ... 2nd rail (lower rail) / 3c ... Feed line (trolley line) / 4 ... Moving body (trolley) ) / 5 ... Robot (robot arm) / 8 ... Control device (control unit) / 13 ... Current collector / 50 ... Base / 51, 52, 53 ... Arm

Claims (5)

A work transfer device that transfers work between multiple work facilities.
A first rail extending along the first horizontal direction in which the plurality of work facilities are lined up, and
Said extends parallel to the first rail, a second rail disposed alongside said first rail below the first rail,
A robot supported by the first rail and the second rail and moving along the first direction, and a robot supported by the moving body that grips a work and delivers it between the plurality of work facilities. And a transport unit including a control device supported by the moving body and controlling the operation of the robot.
The robot is arranged at a position above the first rail and the second rail and overlapping the first rail with respect to a second direction orthogonal to the first direction when viewed from above.
The control device is on the opposite side of the first rail and the plurality of work facilities with respect to the first rail in the second direction, and the first rail and the first rail and the said in the vertical direction when viewed from the second direction. Arranged so as to overlap at least one of the second rails,
Work transfer device. A feeder line extending in the first direction between the first rail and the second rail in the vertical direction and connected to a power source is provided.
The transport unit has a current collector that takes in current from the feeder.
The work transfer device according to claim 1. The first rail and the second rail were arranged so as to overlap each other when viewed from above.
The work transfer device according to claim 1 or 2. The robot has a base attached to the moving body and an arm that is movably supported by the base and grips a work at a tip portion.
The base was arranged so as to overlap the first rail when viewed from above.
The work transfer device according to any one of claims 1 to 3. The transport unit moves between a plurality of positions facing the plurality of work facilities in a state where the arm and the work gripped by the arm are held at positions overlapping the first rail when viewed from above. ,
The work transfer device according to claim 4.

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