CN112469533A

CN112469533A - Automatic workpiece conveyor

Info

Publication number: CN112469533A
Application number: CN201880095838.XA
Authority: CN
Inventors: 加藤正树; 古川和也
Original assignee: Fuji Corp
Current assignee: Fuji Corp
Priority date: 2018-07-24
Filing date: 2018-07-24
Publication date: 2021-03-09
Also published as: JP7041747B2; JPWO2020021615A1; WO2020021615A1

Abstract

The automatic workpiece conveyor performs attitude control of a multi-joint robot arm corresponding to the size of a workpiece, and includes: a traveling table movable along the guide rail; a multi-joint robot arm mounted on the traveling platform, the multi-joint robot arm including a first arm member rotatably supported by a first joint with respect to a support member, a second arm member rotatably supported by a second joint with respect to the first arm member, and a robot arm attached to the second arm member; a turning device mounted on the traveling platform and configured to transfer a workpiece between the turning device and the articulated robot arm; and a controller for controlling the attitude of the multi-joint robot arm by adjusting the angles of the first arm member and the second arm member according to the size of the workpiece when the workpiece is transferred to and from the turning device.

Description

Automatic workpiece conveyor

Technical Field

The present invention relates to an automatic workpiece conveyor that performs attitude control of a multi-joint robot arm according to the size of a workpiece.

Background

An automatic workpiece conveyor for transferring workpieces to and from machine tools is provided in a processing line in which a plurality of machine tools are arranged. Patent document 1 listed below discloses an automatic workpiece conveyor in which an articulated robot arm having a robot at its distal end moves on a traveling table. In this multi-joint robot arm, the upper arm member and the forearm member are coupled via a joint mechanism, and the robot arm at the distal end portion can be moved to a predetermined position by deformation between the folded state and the extended state. Therefore, the articulated robot arm moves to a corresponding position in a folded state, extends relative to the machine tool, enters the processing chamber, and delivers and receives the workpiece by the robot arm.

Documents of the prior art

Patent document 1: international publication WO2015/145575

Disclosure of Invention

Problems to be solved by the invention

The above-described conventional automatic workpiece conveyor has a turning device mounted on the traveling table together with the articulated robot arm, and can turn over the workpiece received by the robot arm on the traveling table. In the transfer of the workpiece between the multi-joint robot arm and the turning device, a posture control has been performed so far to adjust the folding angle of the forearm member while keeping the posture (angle) of the upper arm member constant. This is to maintain a safe posture in which the articulated robot arm does not contact a wall or the like when rotating or moving in a narrow transport space. Therefore, in the conventional automatic workpiece conveyor, if the size of the workpiece to be processed changes, the height of the reversing device needs to be adjusted in accordance with the change, which is very time-consuming.

In view of the above, it is an object of the present invention to provide an automatic workpiece conveyor that performs attitude control of an articulated robot arm according to the size of a workpiece.

Means for solving the problems

An automatic workpiece conveyor according to an aspect of the present invention includes: a traveling table movable along the guide rail; a multi-joint robot arm mounted on the traveling platform, the multi-joint robot arm including a first arm member rotatably supported by a first joint with respect to a support member, a second arm member rotatably supported by a second joint with respect to the first arm member, and a robot arm attached to the second arm member; a turning device mounted on the traveling platform and configured to transfer a workpiece between the turning device and the articulated robot arm; and a controller for controlling the attitude of the multi-joint robot arm by adjusting the angles of the first arm member and the second arm member according to the size of the workpiece when the workpiece is transferred to and from the turning device.

Effects of the invention

According to the above configuration, when the workpiece is transferred between the articulated robot arm and the turning device, the attitude control for adjusting the angles of the first arm member and the second arm member of the articulated robot arm is performed in accordance with the size of the workpiece, whereby the workpiece can be transferred in the same manner even if the size of the workpiece to be processed is changed, and the setup change of the turning device is not required.

Drawings

Fig. 1 is a front view showing a processing machine line.

Fig. 2 is a perspective view showing a work module (lathe module) and a front cover constituting a processing machine line.

Fig. 3 is a perspective view showing an embodiment of the automatic workpiece conveyor.

Fig. 4 is a block diagram showing a control system of the automatic workpiece conveyor in a simplified manner.

Fig. 5 is a diagram illustrating conventional attitude control for the articulated robot arm.

Fig. 6 is a diagram showing the posture control of the present embodiment for the articulated robot arm.

Detailed Description

Next, an embodiment of the automatic workpiece conveyor according to the present invention will be described below with reference to the drawings. In the present embodiment, an automatic workpiece conveyor incorporated in a processing line is described as an example, similarly to the conventional example. Fig. 1 is a front view showing the processing machine line. In the processing line 100, various modular work modules 101 such as machine tools are arranged along the width direction of the machine body. Specifically, a workpiece loading module serving as a workpiece loading section is provided at the right end in the drawing, and various operation modules 101 such as a lathe, a machining center, and a detector are provided in the middle of the workpiece unloading section, i.e., a workpiece discharge module, at the left end in the drawing.

All work modules 101 of the processing machine wire 100 are covered with an exterior cover 102 having the same shape. An openable and closable front cover 103 is formed in a front portion of the housing cover 102, and a conveying space 108 (see fig. 2) extending in the width direction is provided in the entire processing machine line 100. Here, fig. 2 is a perspective view showing a work module 101 (particularly, a lathe module) and a front cover 103 constituting the processing machine line 100.

The work modules 101 are mounted on the base 105 in a state where the adjacent work modules 101 are close to each other. Rails 151 are laid on the base 105, and a machine body such as a lathe or a machining center is assembled to the movable head having wheels in the work module 101. Therefore, the work module 101 mounted on the base 105 can move in the front-rear direction (Z-axis direction) along the rail 151. The work module 101 is provided with a front cover 103 protruding forward as shown in the drawing, and the front cover 103 forms one transport space 108 continuing in the Y-axis direction in the processing machine line 100. Further, an automatic workpiece conveyor is assembled in the conveying space 108.

Fig. 3 is a perspective view showing the automatic workpiece conveyor according to the present embodiment, and particularly shows a state in which a workpiece is transferred to and from the work module 101. The work automatic conveyor 10 has a traveling device 3 incorporated in a front surface portion of a base 105 on which the work module 101 is mounted, and the articulated robot arm 1 is mounted on the traveling device 3. The articulated robot arm 1 enters the inside of the work module 101 in an extended posture as shown in the figure, and moves in the transportation space 108 in an erected state in which it is folded and made compact.

The traveling device 3 has a support plate 21 attached to a front surface portion of the base 105, and a rack 22 and two rails 23 arranged in parallel are fixed to the support plate 21 in a horizontal direction. The traveling table 25 is provided with a slider slidable with respect to the rail 23 and is movable in the lateral direction in accordance with the rail 23. A traveling motor 26 is fixed to the traveling table 25, and a pinion gear 27 attached to a rotary shaft is engaged with the rack 22. Thus, the pinion 27 rolls on the rack 22 by driving the traveling motor 26, and the traveling base 25 can move along the rail 23 on the front surface portion of the base 13.

Next, the articulated robot arm 1 is mounted on the traveling base 25 via the rotating base 18. In the multi-joint robot arm 1, an upper arm member 11 is coupled to a support base 19 fixed to a rotary table 18 via a first joint 13, and a forearm member 12 is coupled to the upper arm member 11 via a second joint 14. The articulated robot arm 1 can perform the angular adjustment of each of the upper arm member 11 and the forearm member 12 by controlling the rotation of the joint motor of each of the first joint 13 and the second joint 14, and can perform the form change of the extended state as illustrated in the drawing and the folded state as described later.

The articulated robot arm 1 is configured such that the folded forearm member 12 is accommodated in the upper arm member 11. Therefore, the pair of left and right upper arm plates of the upper arm member 11 are integrated by the back plate, and are formed into コ -shaped cross sections so as to have a storage space inside. The forearm member 12 is composed of a pair of left and right parallel forearm plates coupled via a second joint 14 on the storage space side thereof, and a robot hand 15 is assembled to the free end side, i.e., the distal end portion of the articulated robot arm 1. The robot hand 15 is pivotally fixed to the forearm member 12 so as to be rotatable about a rotation axis parallel to the rotation axes of the first and

second joints

13 and 14, and hydraulic chucks for gripping a workpiece are provided on both front and back surfaces.

Further, the automatic workpiece conveyor 10 according to the present embodiment is provided with a turning device 5 for turning over a workpiece on the traveling table 25. The turning device 5 is assembled to a support base 19 of the articulated robot arm 1 fixed to the turntable 18. The reversing device 5 is configured such that the pair of gripping claws 17 can grip the workpiece by opening and closing the gripping cylinders. The inverting device 5 is provided with a rotary actuator that rotates compressed air as a working fluid, and can rotate the workpiece held by the holding claws 17 by 180 ° about a vertical rotation axis.

Next, the automatic workpiece conveyor 10 includes a control device 7 for controlling the driving of the articulated robot arm 1, the traveling device 3, and the like. Fig. 4 is a block diagram showing a simplified control system of the automatic workpiece conveyor 10. The control device 7 is mainly a computer including a storage device such as a ROM32, a RAM43, and a nonvolatile memory 34 in addition to the CPU31, and is connected to each of the driving units of the articulated robot arm 1, the traveling device 3, and the turning device 5 via I/035.

In the processing machine line 100, a controller is mounted on each work module 101, and although not shown in detail, a LAN is constructed in which such a work machine-side controller and the controller 7 of the automatic workpiece conveyor 10 are connected via a hub. As shown in fig. 1 and the like, the work module 101 is provided with an operation display device 107 having a touch panel type or button type input means and capable of displaying work information, an operation screen, and the like, inputting a setting value and the like by an operator, and is connected to each control device via a LAN. This enables numerical value input and the like for controlling the automatic workpiece conveyor 10 to be performed from the operation display device 107.

In the control device 7 of the automatic workpiece conveyor 10, a conveying program for controlling conveying paths of the workpieces with respect to the plurality of work modules 101, transfer postures of the articulated robot arm 1, and the like is stored in a memory. In particular, in the present embodiment, an attitude control program 341 is stored which performs attitude control of the articulated robot arm 1 in accordance with the size of the workpiece when the workpiece is delivered to the inverting apparatus 5. The operation display device 107 inputs a workpiece size or the like, which is a numerical value for controlling the attitude of the articulated robot arm 1.

Next, in the automatic workpiece conveyor 10, the articulated robot arm 1 moves in the conveying space 108 of the processing line 100, deforms as shown in fig. 3, enters the inside of the work module 101, and delivers and receives the workpiece. When the two lathes are used to process both surfaces of the workpiece in stages, the workpiece is transferred from the hand 15 of the articulated robot arm 1 to the inverting device 5, the holding claw 17 is rotated to invert the orientation of the workpiece by 180 °, and then the workpiece is returned to the hand 15 again.

As described in the above-mentioned subject section, the workpiece is transferred to and from the inverting apparatus 5 by adjusting the folding angle of the forearm member 12 while the posture (angle) of the upper arm member 11 is kept constant. Fig. 5 is a diagram illustrating such conventional attitude control for the articulated robot arm 1. The posture of the upper arm member 11 at a constant angle is set so that an upper arm axis 41 connecting the two rotation axes of the first joint 13 and the second joint 14 is substantially vertical. The operation angle θ n (θ 1, θ 2) of the forearm shaft 42 connecting the second joint and the two rotation shafts of the robot 15 is adjusted in accordance with the size of the workpiece W (W1, W2).

The a mode and the B mode shown in fig. 5 show a state in which the articulated robot arm 1 delivers the workpieces W1 and W2 having different thicknesses Tn (T1 and T2) to the inverting apparatus 5. When the reversing device 5 is set to the fixed position, the transfer position of the robot 15 needs to be changed according to the size of the workpiece W. The workpiece Wn is picked up by the reversing device 5 so that the gripping claws 17 grip the central portion of the thickness Tn of the workpiece Wn. In such a case, in the workpieces W1, W2 having different sizes, a difference occurs in the operation angles θ 1, θ 2 of the forearm shaft 42 and the distance (transfer height) Hn (H1, H2) between the first joint 13 and the rotation axis (center of the workpiece Wn) of the robot 15.

The difference in the size of the workpiece Wn is a difference in the delivery position of the robot 15, but up to now, this difference is dealt with by adjusting the operation angle θ n of the forearm shaft 42. Further, if only the adjustment of the angle θ n is performed, the difference in the delivery height Hn becomes excessively large, and there is a case where appropriate delivery cannot be performed between the robot 15 and the inverting unit 5. Accordingly, when the size of the workpiece Wn to be processed is changed, the worker needs to perform setup adjustment for adjusting the mounting height of the inverter device 5. Therefore, there has been a problem that a delivery error may occur and a setup of the reversing device 5 is required for reliable delivery.

In this regard, in the present embodiment, the workpiece size (the value of the arbitrary thickness Tx) is input from the operation display device 107, and the operation angle θ n of the upper arm shaft 41 and the operation angle θ n of the forearm shaft 42 with respect to the upper arm shaft 41 are calculated in accordance with the posture control program 341, whereby the posture control of the articulated robot arm 1 is performed based on the respective appropriate values. Fig. 6 is a diagram showing the posture control of the present embodiment with respect to the articulated robot arm 1.

In the attitude control program 341 for executing the attitude control, control is performed such that the gripping claws 17 of the inverter 5 can grip the workpiece Wn in the same state by a combination of the operation angles θ n of the upper arm shaft 41 and the forearm shaft 42. Here, the same gripping state of the workpiece W by the inverting device 5 means that the gripping claw 17 grips the workpiece Wn at the center portion of the thickness Tn and the distance (transfer height) Hx between the first joint 13 and the rotation axis of the robot 15 (the center of the workpiece Wn) is constant as in the conventional art. This is because the gripping claws 17 always grip the central portion of the workpiece Wn by keeping the delivery height Hx constant.

In the example of fig. 6, when the workpiece W1 is large in size, the operation angle θ 32 of the upper arm shaft 41 with respect to the vertical reference line 40 is larger than the operation angle θ 42 of the upper arm member 41 when the workpiece W2 is small in size. Further, an operation angle θ 31 of the front arm shaft 42 with respect to the upper arm shaft 41 in the case of the workpiece W1 is smaller than the operation angle θ 41 in the case of the workpiece W2. By adjusting the respective operation angles θ n, the delivery height Hx is always constant even when the workpiece sizes are different.

Therefore, in the automatic workpiece conveyor 10 according to the embodiment, when the workpiece Wn is processed in the processing machine line 100, the operator inputs the workpiece size Tn from the operation display device 107, and thus the stable transfer of the workpiece between the articulated robot arm 1 and the inverter 5 can be realized without requiring the setup change of the inverter 5.

In the automatic workpiece conveyor 10, in addition to the reversing of the workpiece W by the reversing device 5, the operation operations such as the reversing of the robot 15 and the rotation of the articulated robot arm 1 are also performed. However, since the upper arm shaft 41 of the articulated robot 1 is inclined, the robot 15 and the articulated robot 1 interfere with the front cover 103 and the like constituting the narrow transport space 108 during the operation depending on the magnitude of the operation angle θ n.

Then, the tilt angle range θ dn of the upper arm shaft 41 that can be operated is set based on the size of the conveyance space 108. Thus, when the upper arm shaft 41 is tilted within the tilt angle range θ dn, the operation such as the turning of the robot 15 and the rotation of the articulated robot arm 1 is directly performed. On the other hand, when the workpiece W is transferred in a posture in which the arm member 11 is tilted beyond the tilt angle range θ dn, the upper arm shaft 41 is raised vertically or within the tilt angle range θ dn, thereby avoiding interference of the articulated robot arm 1.

While one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.

For example, the automatic workpiece conveyor 10 and the processing machine line 100 are examples, and may have different configurations.

Description of the reference numerals

1 … multi-joint robot arm 3 … walking device 5 … turnover device 7 … control device 10 … automatic workpiece conveyor 11 … upper arm part 12 … forearm part 13 … first joint 14 … second joint 15 … robot 17 … holding claw 40 … reference line 41 … upper arm shaft 43 … forearm shaft 100 … processing line 101 … operation module 108 … transportation space 341 … attitude control program.

Claims

1. An automatic workpiece conveyor comprising:

a traveling table movable along the guide rail;

a multi-joint robot arm mounted on the traveling platform, the multi-joint robot arm including a first arm member rotatably supported by a first joint with respect to a support member, a second arm member rotatably supported by a second joint with respect to the first arm member, and a robot arm attached to the second arm member;

a turnover device mounted on the walking platform and used for transferring workpieces between the turnover device and the multi-joint mechanical arm; and

and a controller that performs attitude control of the articulated robot arm by adjusting the angles of the first arm member and the second arm member according to the size of the workpiece when the workpiece is transferred to the turning device.

2. The automatic workpiece conveyor according to claim 1,

having an input device for inputting the size of the workpiece,

the control device calculates an angle between the first arm member and the second arm member based on the value input by the input device, and performs attitude control of the multi-joint robot arm.

3. The automatic workpiece conveyor according to claim 1 or 2,

the articulated robot arm and the turning device are mounted on the walking board via a rotating device, and the control device performs attitude control of the articulated robot arm in accordance with driving of the rotating device.