WO2014128766A1

WO2014128766A1 - Transportation device and workpiece transportation method using same

Info

Publication number: WO2014128766A1
Application number: PCT/JP2013/001075
Authority: WO
Inventors: 高橋　孝治; 勝美南東
Original assignee: 株式会社エイチアンドエフ
Priority date: 2013-02-25
Filing date: 2013-02-25
Publication date: 2014-08-28
Also published as: JPWO2014128766A1; JP5798689B2

Abstract

[Problem] To provide a transportation device capable of preventing quality from decreasing or the workpiece from falling due to deflection in the workpiece during transportation, and a workpiece transportation method using the same. [Solution] The present invention is a transportation device (100) in which robots (10) that face each other simultaneously grip a workpiece (W) and transport the workpiece (W), each of the robots (10) being provided with: a base (1); an arm unit (2) rotatably mounted on the base (1); a grip unit (3) for gripping the workpiece (W), the grip unit (3) being provided to the distal end of the arm unit (2); and a contact means mounted on the grip unit (3), the workpiece (W) being transported while the distal ends of support rods of the contact means of the robots (10) that face each other are being pressed against each other and kept in supported state.

Description

Conveying apparatus and work conveying method using the same

The present invention relates to a transfer device and a method of transferring a workpiece using the transfer device, and more specifically, a transfer device that can prevent deterioration in quality due to bending of the workpiece during transfer and can also prevent a transfer error due to dropping of the workpiece and the same. The present invention relates to a work conveying method.

In an apparatus for processing a workpiece such as a press device, the workpiece is continuously transferred between the press devices using a transfer device.
Various types of such transport devices have been studied. For example, a multi-axis robot, a first handling arm supported at one end by the tip of the multi-axis robot, and one end at the other end of the first handling arm. A conveying device having a second handling arm that is rotatably coupled, a driving device for rotationally driving the second handling arm, and a gripping device fixed to the other end of the second handling arm is known. (For example, refer to Patent Document 1 or 2).
There is also known a transport device including a robot, a linear motion mechanism having a carrier attached to the tip of a robot arm and linearly driven by a belt, and a workpiece gripping mechanism attached to the carrier (for example, (See Patent Document 3).

In recent years, with the diversification of industrial materials, large-sized workpieces (steel plates and the like) to be conveyed have appeared.
However, when a large workpiece is transferred, the conventional transfer device cannot always hold the workpiece in a balanced manner, so that there is a drawback that the position of the workpiece is greatly shifted or the workpiece is dropped in some cases.

On the other hand, a method of simultaneously gripping and transporting a workpiece using two synchronized robots arranged in parallel is used.
That is, a method is used in which a robot is arranged so as to face both sides of a workpiece, a fixed handling arm provided in each robot is synchronously controlled, a single workpiece is gripped, and conveyed.

JP 2001-225286 A JP 2001-30190 A JP 2010-94695 A

By the way, in the transfer device using the two robots described above, the horizontal rotation and the vertical rotation with respect to the axes of the handling arms of the two robots are respectively controlled synchronously by a motor to grip and transfer the workpiece. Therefore, when the workpiece is transported at an extremely low speed, the workpiece can be linearly fed in the transport direction.

However, when a workpiece is fed at high speed, both the tracking control error inevitably generated in the transfer device, the gap between the mechanical transmission parts (internodes, etc.) of the handling arm, backlash, etc. Even if the interval between the handling arms is set to be constant, a variation in the interval of about 10 to 20 mm occurs.
Specifically, as shown in FIG. 6, the handling arm rotates about the axis of the robot, so when the workpiece on the upstream side is transported to the position close to the robot, the robot Even if it is controlled so that it moves linearly, due to its tracking control error and backlash of the mechanical transmission part, it is affected by the centrifugal force, and the transport trajectory B (that is, the trajectory where the handling arms approach each other) )
Then, the gripped work is subject to fluctuations that are narrowed down in the direction of the arrow from the robots on both sides.
Thereby, as schematically shown in FIG. 7, the work W1 itself is bent, and as a result, the work W1 has poor quality.
In extreme cases, the suction pad is detached from the workpiece W1 in the vicinity of the bending, and other suction pads are also successively removed in a manner linked to the workpiece W1, so that the workpiece W1 falls, resulting in a so-called serious conveyance error.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transport apparatus capable of preventing quality deterioration and work drop due to bending of a work during transport, and a work transport method using the same.

The inventors of the present invention have intensively studied to solve the above-mentioned problems. As a result, each of the opposing robots is provided with contact means, and the tips of the support rods are contacted and supported, thereby forcing the arm portion from the transport track. The present inventors have found that it is possible to prevent the occurrence of a problem and have completed the present invention.

According to the present invention, (1) in a transfer device capable of simultaneously gripping a workpiece by opposing robots and transferring the workpiece, each robot has a base portion, an arm portion rotatably attached to the base portion, and the arm A gripping part for gripping a workpiece provided at the tip of each part and a contact means attached to the gripping part, and the tips of the support rods of the contact means of each opposing robot are in contact with each other Therefore, it exists in the transfer device to which the workpiece is transferred.

The present invention resides in (2) the transfer device according to (1), in which the workpiece is transferred in a state where the distance between the gripping portions of the opposing robots is constant.

The present invention resides in (3) the transfer device according to the above (1) or (2) in which the support rod can be moved forward or backward.

The present invention resides in (4) the transfer device according to (3), wherein the contact means is an air cylinder, and the forward or backward movement of the support rod is controlled by the air cylinder.

According to the present invention, (5) the gripping part of at least one of the opposing robots is connected to the arm part via a pressure device, and the pressure device eliminates the mechanical load on the arm part ( 1) It exists in the transfer device according to any one of (4).

In the present invention, (6) the repressing device includes an LM rail connected and fixed to the grip portion, an LM guide that can slide along the LM rail, a lower surface connected to the LM guide, and an upper surface connected to the arm portion. The conveying apparatus according to the above (5), comprising: the plate, a stopper with which one end of the plate abuts, and an urging unit that urges the plate toward the stopper with a constant pressure.

The present invention resides in (7) the transfer device according to (6), wherein the urging means is an air cylinder.

The present invention is (8) a method for transferring a workpiece using the transfer device according to any one of (1) to (7) above, wherein a gripping portion of an opposing robot holds the workpiece and faces the workpiece. There is a workpiece transfer method in which the workpiece is transferred so that the distance between the gripping portions becomes constant after the tips of the support rods of the contact means of the robot are in contact with each other.

In the transfer device of the present invention, the workpiece is transferred with the tips of the support rods of the contact means of the opposing robot in contact with each other, so that the arm portion is not forced to be displaced outward from the transfer track. can do.
For this reason, even if it is a large sized workpiece | work, it can prevent that the position of a workpiece | work shift | deviates significantly or a workpiece | work falls by using the robot which opposes simultaneously.
In addition, by making the distance between the gripping portions of the robots facing each other constant, it is possible to prevent quality degradation and workpiece drop due to bending of the workpiece during conveyance.

In the transfer device of the present invention, the support rod can be switched so as to move forward or backward. Therefore, when the workpiece is transferred, the support rod is advanced so that the tips of the support rods come into contact with each other, and the workpiece is not transferred. The support rods can be moved backward so as not to obstruct the movement of the arm portion.
At this time, if the contact means is an air cylinder and the forward or backward movement of the support rod is controlled by the air cylinder, the support rod can be easily moved forward or backward.

In the transfer device according to the present invention, the gripping portion of at least one of the opposing robots is connected to the arm portion via the pressure device, and the pressure device eliminates the mechanical load on the arm portion. It has become.
For example, in a compression device fixed to the gripping part, the arm part is elastically pressed against the inner stopper by the biasing means, and when a centrifugal force is applied to the gripping part and the arm part during work transfer, the arm part In order to eliminate the load on the arm, it works to release (guide) the arm part outward along the LM rail.
At this time, if the biasing means is an air cylinder, the arm portion can be easily pressed.

In the workpiece transfer method of the present invention, after the gripping portions of the opposing robot grip the workpiece and the tips of the support rods of the contact means of the opposing robot are in contact with each other, the distance between the gripping portions is By conveying the workpiece so as to be constant, it is possible to prevent quality degradation and workpiece drop due to bending of the workpiece.

FIG. 1 is a schematic side view showing an embodiment of a transport apparatus according to the present invention. FIG. 2A is a schematic side view showing a state in which the support rod of the contact means of the transport apparatus according to the present embodiment is retracted, and FIG. 2B is the contact of the transport apparatus according to the present embodiment. It is a schematic side view which shows the state which the support rod of the means advanced. FIG. 3 is a schematic top view showing the transport track of the gripper when the transport device according to the present embodiment transports a workpiece. FIG. 4 is a schematic side view showing a state of the gripping unit at a position approaching the robot when the transfer device according to the present embodiment transfers a workpiece. Fig.5 (a) is a schematic side view which shows the detail of the oppression apparatus in the conveying apparatus based on this embodiment, FIG.5 (b) shows the state which made the arm part slide from the state of Fig.5 (a). It is a schematic side view shown. FIG. 6 is a schematic top view showing a path along which a conventional conveying apparatus conveys a workpiece. FIG. 7 is a schematic side view showing the state of the gripper at a position where the conventional transfer device approaches the robot when transferring the workpiece.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.
In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified.
Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

The transfer apparatus according to the present invention is an apparatus in which a pair of opposed robots simultaneously picks and holds a workpiece and transfers the workpiece.
FIG. 1 is a schematic side view showing an embodiment of a transport apparatus according to the present invention.
As shown in FIG. 1, the transport apparatus 100 according to the present embodiment includes an opposing robot (hereinafter also simply referred to as “both robots”) 10.
Both robots 10 have the same structure.

Both robots 10 each have a base 1, an arm 2 attached so as to be rotatable with respect to the base 1, and a grip 3 for gripping a workpiece provided at the tip of the arm 2. And an air cylinder 5 (hereinafter referred to as a “first air cylinder” for convenience) attached to the grip portion 3.
Both robots 10 transport the work W adsorbed and gripped by the grip portion 3 by rotating the arm portion 2 with a motor (not shown) about the base portion 1 as an axis.

Here, in the transfer apparatus 100, both robots 10 are driven under synchronous control.
That is, the opposing robot 10 simultaneously picks and holds the workpiece W from both sides with the gripping part 3, and the horizontal rotation and the vertical rotation with respect to the axis of the arm part 2 of both robots 10 are controlled synchronously by a motor (not shown). Then, the workpiece W is conveyed.

The grip portion 3 includes a plurality of suction pads 31. The suction pads 31 can be decompressed by decompression means (not shown).
In the transport apparatus 100, the gripping unit 3 of both robots 10 comes into contact with the workpiece W, and the suction pad 31 is depressurized, whereby the workpiece W is chucked and gripped by the gripping unit 3.
The gripping unit 3 sucks and holds the workpiece W with a certain vertical allowable width when sucking the workpiece W.

The pressure (the negative pressure from 1 atm) at the time of decompression of the decompression means is preferably −0.8 to −0.3 kgf / cm ² from the viewpoint of reliably attracting and gripping the workpiece W.

FIG. 2A is a schematic side view showing a state in which the support rod of the contact means of the transport apparatus according to the present embodiment is retracted, and FIG. 2B is a contact means of the transport apparatus according to the present embodiment. It is a schematic side view which shows the state which the support rod advanced.
As shown in FIG. 2A and FIG. 2B, in the conveying device 100, the support rod 4 of the first air cylinder 5 that is a contact means moves forward or backward in a direction perpendicular to the moving direction of the workpiece. It is possible to position at two positions: a forward position (see FIG. 2B) and a backward position (see FIG. 2A).
The first air cylinders 5 of both robots 10 are also driven in synchronization.
That is, the robot 10 is activated simultaneously with both robots 10 so that the support rod 4 of the first air cylinder 5 moves forward or backward.

In the transport device 100, the support rods 4 facing each other can be moved forward or backward. Therefore, when the workpiece W is transported, the support rods 4 are moved forward so that their tips come into contact with each other as will be described later ( In this state, the support rods are in a pressure contact state), and when the workpiece W is not transported, the support rods 4 can be retracted (retracted) to a position that does not get in the way.
Further, in the transport device 100, the advancement degree of the support rod 4 can be appropriately adjusted according to the size of the workpiece W.

Here, the forward or backward movement of the support rod 4 is controlled by the first air cylinder 5. In the first air cylinder, air flows into one cylinder chamber partitioned in the cylinder, and the other cylinder chamber is opened, so that the support rod 4 moves forward, opens one cylinder chamber, and opens the other cylinder chamber. The support rod 4 moves backward by flowing air into the cylinder chamber.
Thereby, it is possible to easily and accurately adjust the degree of forward or backward movement of the support rod 4.
In addition, when the tips of the support rods 4 are in contact with each other, both the first air cylinders 5 are applied with a predetermined air pressure by the first first air cylinders 5 so as to be balanced at the center. Thus, the abutted and supported state is maintained.
Note that a predetermined air pressure is always applied to both the first air cylinders 5 during the transfer of the workpiece.

FIG. 3 is a schematic top view showing the transport track of the gripper when the transport device according to the present embodiment transports a workpiece.
As shown in FIG. 3, in the transfer device 100, when the workpiece W is transferred at high speed from the upstream position P1 to the downstream position P3 via the position P2 approaching the robot, The work W is conveyed in a state where the tips of the support rods 4 of the 1 air cylinder 5 are in contact with each other.
As a result, as the arm portion 2 approaches the position P2 where the robot approaches the robot, the transfer trajectory of the grip portion 3 is prevented from shifting outward due to centrifugal force (see FIG. 6).
That is, the conveying device 100 is configured such that the gripping portion 3 is forcibly transported by the tips of the support rods 4 of the first air cylinders 5 of both robots 10 being abutted and supported by a predetermined pressing force (air pressure). You will pass A.
At this time, the air pressure in the first air cylinder 5 when the tips of the support rods 4 are in contact with each other is set larger than the centrifugal force that the first air cylinder 5 tends to shift outward. is important.
Moreover, in the conveying apparatus 100, since the front-end | tips of the support rod 4 of the 1st air cylinder 5 of both robots 10 are contact-supported, the holding | grip part 3 will move directly, Therefore It opposes at the time of conveyance. The distance between the grip portions 3 of the robot 10 is always constant.

FIG. 4 is a schematic side view showing a state of the gripping unit at a position approaching the robot when the transfer device according to the present embodiment transfers a workpiece.
In the transfer device 100, since the distance H between the gripping portions 3 of the opposing robots 10 at the time of transfer is always constant, the position P2 approaching the robot when transferring the workpiece is also as shown in FIG. The work W can be prevented from bending.
Thereby, the quality degradation of the workpiece | work W and the workpiece | work W fall can be prevented.

In the transfer device 100 according to the present embodiment, the gripping unit 3 of one of the opposing robots is connected to the arm unit 2 via a pressure device.
Fig.5 (a) is a schematic side view which shows the detail of the oppression apparatus in the conveying apparatus based on this embodiment, FIG.5 (b) shows the state which made the arm part slide from the state of Fig.5 (a). It is a schematic side view shown. In FIG. 1, FIG. 2, and FIG. 4, the repressing device is omitted.
As shown in FIG. 5A, the repressing device 6 includes an LM rail 61 that is integrally fixed to the grip portion 3, an LM guide 62 that can slide along the LM rail 61, and a lower surface that is an LM guide 62. A plate 63 that is fixed integrally and whose upper surface is integrally fixed to the arm portion 2, a stopper 64 that can be brought into contact with one end of the plate 63 and that is integrally fixed to the grip portion 3, and a constant pressure on the plate 63. And an air cylinder 65 (hereinafter referred to as “second air cylinder” for convenience) which is an urging means for urging the stopper 64.

In the conveying device 100, the repressing device 6 fixed to the gripping unit 3 is configured so that when the arm unit 2 is at the upstream position P1 or the downstream position P3 (see FIG. 3), the second air cylinder 65 2 is pressed against the inner stopper via the plate 63 (left direction in FIG. 5).
As a result, the plate 63 is fixed at a position in contact with the stopper 64.
That is, the holding part 3 and the arm part 2 are fixed in position.
When the arm portion 2 is at the upstream position P1 or the downstream position P3, the tips of the support rods 4 of the abutting means (first air cylinder 5) of the opposing robot 10 abut at a predetermined pressure. It is in the state that was done.

For example, as described above, when the workpiece W is transported to the position P2 approaching the robot, an outward centrifugal force is applied to the grip portion 3 and the arm portion 2.
At this time, since the tips of the support rods 4 of the first air cylinder 5 of the opposed robot 10 described above are in contact with each other, the distance H between the gripping portions 3 is always constant.
On the other hand, since such an abutting means is not provided in the arm part 2, it tends to shift | deviate outside from a conveyance track | orbit by centrifugal force.
That is, the arm part 2 receives the load to the outside.
On the other hand, in the transport apparatus 100, as shown by the arrow in FIG. 5B, the arm unit 2 slides on the LM rail 61 via the plate 63 and moves outward. The unreasonable load on the arm part 2 is eliminated.

Here, the repression by the urging means is controlled by the second air cylinder 65. The second air cylinder is in a state where the plate 63 is always pressed against the stopper 64 by flowing air into one cylinder chamber partitioned in the cylinder and opening the other cylinder chamber.
Thus, by using the second air cylinder 65 as the urging means, it is possible to easily press the arm part.

In the transport device 100, the above-described pressure device (second air cylinder) can press the grip portion 3 against the stopper 64 and fix it to the arm portion 2, while the robot grip portion 3 moves outward. The arm portion 2 can be guided outward.
For this reason, the mechanical load to the arm part 2 can be eliminated.
The air pressure of the second air cylinder 65 is set smaller than the air pressure of the first first air cylinder 5.

As described above, according to the transport apparatus 100 according to the present embodiment, the workpiece is transported in a state where the tips of the support rods 4 of the first air cylinder 5 of the opposing robot are in contact with each other. From being forced out of the way.
For this reason, even if it is a large-sized workpiece | work W, the robot 10 which opposes simultaneously is used, and the workpiece | work W is conveyed in the state which made the front-end | tips of the support rod 4 of the 1st air cylinder 5 of both robots 10 contact | abut. Thus, it is possible to prevent the position of the workpiece W from being greatly displaced or dropping the workpiece W.
In addition, since the conveying device 100 includes the compression device 6, it is possible to eliminate the load on the arm portion 2 while maintaining the direct movement of the grip portion 3.

Next, a method for conveying a workpiece using the conveyance device 100 will be described.
First, in the method for transporting the workpiece W according to the present embodiment, the gripping units 3 of both robots 10 suction and grip the workpiece W.
Then, the support rod 4 of the first air cylinder 5 of both robots 10 is advanced at that position, and the tips of the support rods 4 abut against each other.
At this time, the tips of the support rods 4 are abutted and supported so that the workpiece W does not bend. At this time, a predetermined air pressure is applied to both the first air cylinders 5.

While maintaining this state, the arm portions 2 of both robots 10 are rotated (P1 → P3), and the workpiece W is conveyed.
At this time, since the tips of the support rods 4 of the first air cylinders 5 of both robots 10 are in contact with each other, the distance between the gripping portions 3 is always constant.

After the conveyance, the grip portion 3 releases the workpiece W and the first air cylinder 5 moves the support rod 4 backward.
Then, the gripping portions 3 of both robots 10 are returned to the position of the next set workpiece W. At this time, since the support rod of the first air cylinder 5 is retracted (retracted), it does not get in the way.
By repeating such an operation, the workpiece W is continuously conveyed.

In the workpiece transfer method of the present invention, after the gripping portion 3 of the opposing robot 10 sucks and grips the workpiece W, the tips of the support rods 4 of the first air cylinder 5 of the opposing robot 10 abut each other, By conveying the workpiece W so that the distance between the gripping portions 3 is constant, the workpiece W is not bent.
Therefore, there is no deterioration in the quality of the workpiece W.
Moreover, since the workpiece | work W itself does not bend, the adsorption | suction pad 31 does not come off.
Therefore, according to the method for conveying a workpiece, it is possible to prevent quality degradation and workpiece W dropping due to bending of the workpiece W.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment.

In the transport apparatus 100 according to the present embodiment, the first air cylinder 5 is used as the contact means, but the present invention is not limited to this as long as it has a function with a linear motion mechanism similar to this.
For example, a shock absorber, a ball screw, a rack and pinion, a linear motor, or the like can be used in combination as appropriate.

In the transport apparatus 100 according to the present embodiment, the second air cylinder 65 is used as the biasing means, but is not limited to this as well.

The conveyance device of the present invention is suitably used in the field of press working.
In particular, when a large workpiece is transported, it is possible to prevent deterioration in quality and workpiece drop due to bending of the workpiece during transport.

DESCRIPTION OF SYMBOLS 1 ... Base part 2 ... Arm part 3 ... Holding part 4 ... Supporting rod 5 ... 1st air cylinder 6 ... Repressor 10 ... Robot 31 ... Adsorption pad 61. .... LM rail 62 ... LM guide 63 ... Plate 64 ... Stopper 65 ... Second air cylinder 100 ... Conveying device A, B ... Conveying track P1 ... Upstream position P2: Position approaching the robot P3: Downstream position W: Workpiece

Claims

In the transfer device that can grip the workpiece at the same time by the opposing robot and transfer the workpiece,
Each robot has a base, an arm part rotatably attached to the base, a gripping part for gripping the workpiece provided at the tip of the arm part, and a contact means attached to the gripping part With
A transfer device for transferring the workpiece in a state in which the tips of the support rods of the contact means of each of the opposed robots are in contact with each other.
The transfer apparatus according to claim 1, wherein the workpiece is transferred in a state where a distance between the gripping portions of the robots facing each other is constant.
The conveying device according to claim 1 or 2, wherein the support rod is capable of moving forward or backward.
The contact means is an air cylinder;
The transport apparatus according to claim 3, wherein the forward or backward movement of the support rod is controlled by the air cylinder.
The gripping part of at least one of the opposing robots is connected to the arm part via a repressing device,
The conveying device according to any one of claims 1 to 4, wherein the repressing device eliminates a mechanical load on the arm portion.
An LM rail connected and fixed to the gripping portion; an LM guide slidable along the LM rail; a plate having a lower surface connected to the LM guide and an upper surface connected to the arm portion; 6. A transport apparatus according to claim 5, further comprising a stopper with which one end of the plate is abutted, and a biasing means for biasing the plate toward the stopper with a constant pressure.
The transfer device according to claim 6, wherein the biasing means is an air cylinder.
A workpiece transfer method using the transfer device according to any one of claims 1 to 7,
The gripping part of the robot facing the grips the workpiece,
After the tips of the support rods of the contact means of the robot facing each other contact each other,
A work transporting method for transporting the work such that a distance between the gripping parts is constant.