JPS60228090A - Method of carrying article by robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for transporting articles by an industrial robot.

There are cases where a large amount of articles loaded on a pallet are picked one by one by an industrial robot and fed one by one to a separately provided conveyor or the like. The transfer process (pallet-conveyor) as described above is mostly aimed at orderly and forceful supply of articles to another processing line, and therefore, the article is supplied onto the conveyor in a certain posture. It is desirable that this be done at a fixed location, and in that sense there is an advantage to using an industrial robot as described above.

However, the loading of goods onto the pallet is often done manually, and the positions and postures of the goods loaded on the pallet vary (particularly when it comes to almost symmetrical goods). In some cases, it may be difficult to align the orientation of the items), and if the items are held and conveyed by a robot as they are, the posture (orientation) and position of the items on the conveyor will not be constant.

Methods to resolve the above-mentioned inconvenience include installing a new correction device on the conveyor that checks the posture of the articles transferred onto the conveyor and corrects it if the posture is different from the normal one, or One idea would be to provide a guide jig that resembles the shape of the items on the pallet so that the position and posture of the items placed on the pallet are always the same, but the former would result in a time loss due to increased travel. In the latter case, if a guide jig is installed, the position and posture (orientation) of the items on the pallet will always be the same. Although,
On the other hand, there are disadvantages in that it takes time for a worker to load articles onto a pallet, and it is difficult for a robot to pick up articles from the pallet. In other words, the guide jig on the pallet needs to support the articles with a certain degree of freedom.

Therefore, the present invention provides a guide jig on a pallet that has a certain degree of freedom, so that even if the posture (orientation) of the articles loaded on the pallet varies, the articles can be guided as described above. The purpose is to propose a transport method that allows transport and transfer without causing any drawbacks, and examples will be described below based on the drawings.

That is, Figure 1 is a side view of a system for conveying and transferring an automobile engine camshaft (item) (2) using a robot (1) in an orthogonal coordinate system. It consists of an extending fixed rail (3), a rail frame (4) that runs on the rail (3), and an elevating hand device (5) that runs on the rail frame (4) along the Y-axis direction, The robot hand (6) at the lower end of the hand device (5) grasps the camshafts (2) on the pallet (Pi) one by one and transports them onto a nearby conveyor (7'). The lifting and lowering directions of the hand (6) are biaxial directions.

The pallet (P) is provided with horizontal bars (9) in multiple stages on the side of a box-shaped frame (8), and V is provided at regular intervals on the horizontal bars (9).
A camshaft (article) (2) that has a letter-shaped support jig (11) fixed thereto, and is supported on the support jig (11).
is installed on the floor along the Y-axis direction.

As shown in Fig. 2.3, the robot hand (6) is attached to the lower end of the lifting arm (12) through a bracket (13) at an angle of 45 degrees.
14), the robot moves up and down along the above-mentioned 45 degree angle. (1
5) is a guide rod, (16) is a guide cylinder on the bracket side, and the robot hand (6) is connected to this guide rod (16).
a base (17) to which the base (15) is fixed, and the base (17)
A rotating frame (18) that can rotate freely relative to
) and a rotary actuator (21) for rotating the rotating frame (18), and the rotary actuator (21) has its rotating shaft (21a) aligned with the base (
The key (22) is fixed to the frame (2)
1b) is fixed to the rotating frame (18) with a bolt (23), thereby driving the rotating frame (18) to rotate.

(24) accurately adjusts the rotation angle of frame (18) to 180 degrees.
(25) is a stopper protrusion on the rotating frame (18) side.

Next, the gripping claw device (19) will be explained. The gripping claw device (19) consists of a pair of claws (27) pivoted on a support bracket (26) protruding from a rotating frame (18). members (28) (29), and the claw member (28) (
29) Insert the opening into the elongated hole drilled at the end of the force point side (31a).
The opening/closing drive cylinder (3) engages the pin (32) at the tip.
1), and when the cylinder (31) expands and contracts, the tips of the claw members (28) and (29) open and close. (33) is a spring that always biases the claw members (28) and (29) in the closing direction; (34) is an upper and lower electromagnetic switch that detects the position of the piston (35) in the cylinder (31); The electromagnetic switch 7 (34) can be slid freely along the rail (36) on the side of the cylinder and can be mounted on the cylinder.
The mounting position can be freely adjusted by turning (37) (Figure 4). In other words, by changing the mounting position of this electromagnetic switch (34), the claw member (
28) The opening amount in (29) can be detected at any desired amount.

Then, using the robot (1), the camshaft (2) is transported in the following manner.

In other words, the camshaft (2) is
(The camshafts (2) are arranged in advance along the Y-axis direction on the Pi support jig (11), and the control device (not shown) of the robot (1) sequentially moves the arranged camshafts (2) to the top It contains a program to pink the edges and transfer and place them on the conveyor (7).
operates according to the program, but the product in this example, the cam 7 shaft (2), is asymmetrical, and
y (as shown in the third figure on the Pi support jig (11),
The following operation is performed for the camshaft (2) placed in the left-right direction opposite to the preset direction.

That is, in this example, robot (1) is
) is taught to hold and lift at the Y-axis position shown in the third figure, and the camshaft is placed on the jig (11) in a normal posture with the right and left direction opposite to that shown in the third figure. When gripping (2), the right claw member (28) grips the (5) portion of the shaft, and the left claw member (29) grips the (81) portion of the shaft. For the cam 7 shaft (2) in the opposite orientation shown in Figure 3, the claw member (28) on the right side is attached to the cam portion of the shaft (2).
q, the left claw member (29) grips the 0 part of the shaft, and the cam part (q holds the other shaft part (A)
) (B) (Since it has a slightly larger diameter than the DJ,
The claw member (28) on the right side is the shaft part (A) (B)
(The amount of closing when gripping Q is also smaller than the amount of closing when gripping Q.)

In other words, the cylinder (31) of the right gripping claw device (19)
Since the amount of contraction of the shaft part (4) (B) 0 is smaller than that when the shaft part (4) (B) 0 is normally gripped, this is detected by the electromagnetic switch (34) for detecting the position of the piston in the cylinder, and the detection signal is to the control device of the robot,
The robot (1) is made to perform the following actions.

That is, if it is detected in the first gripping operation that either of the gripping claws (28) (29) is closed by a smaller amount than the predetermined closing amount, in this embodiment, the hand ( 6) stops the gripping operation, opens both claw members (2s) (29), contracts the cylinder (14), and temporarily leaves the camshaft (2). Then, after moving the entire lifting/lowering device (5) a certain distance along the Y-axis direction (Fig. 3 (Hakama)), the rotary actuator (
21) to turn the entire gripper (6) 180 degrees, and with the palm of the hand (6) turned back, the cylinder (14) is extended again, and each gripping claw device (19)
to grip the shaft parts (A) and (B).

During this second gripping, each claw member (28) (29
) grips the shaft part (8) (uniformly), which is the same as when the cam 7 shaft (2) is placed in the normal direction, so the detection signal is output, and the hand (6) grips the entire shaft (2). While keeping the cylinder (14) in place, contract the shaft (2).
) diagonally upward from the support jig (11) (second
Dot-dashed line - dashed-double line - solid line), hereinafter referred to as the lifting hand device (
5) in each of the X, Y, and Z directions to transfer the shaft (2) onto the conveyor (7), and during the transfer, the rotary actuator (21) is operated again to move the hand (6). The camshaft (2
) is placed on the upper conveyor (7>) which has been corrected to its normal orientation.

In addition, in the robot of the above embodiment, the hand (6) is an arm (
12) Since the camshaft (goods) (2) is picked by moving diagonally at the end, the pallet supporting jigs (11) are installed in positions that overlap vertically in each stage as shown in the first and second figures. Even if the camshaft (2) is lifted diagonally by a predetermined amount, the camshaft (2) can be fixed to the support jig (1).
1) and is held at an intermediate position between the supporting jigs (11) so as not to interfere with the upper supporting jigs (11).
6) If the entire camshaft (2) is raised, the camshaft (2) will be able to lift the pallet H without contacting the pallet (pH support jig (11)).
D Lifted upwards.

In addition, in the above example, either gripping claw (28) (29)
If the gripping operation does not reach the predetermined closing amount, the -th gripping operation is stopped and the hand (6) is moved to the camshaft (article) (
2), rotate the hand half a turn near the camshaft (2), then grip the camshaft (2) with the half-rotated hand (6), and again during the transfer process to the conveyor (7). By rotating the hand (6) half a turn, the posture of the camshaft (article) was correctly corrected and it was able to be placed on the conveyor (7). ) Even if it is detected that the posture in (2) is not normal, the gripping operation will continue without stopping and will be lifted up and placed on the conveyor (7).
On the way to transfer the hand (6) half a turn,
It may be placed on the conveyor (7) with its posture corrected normally.

Furthermore, in the above example, the camshaft (2) that is the article has a large diameter part and a small diameter part, and the normal gripping state and the abnormal gripping state are due to the difference in diameter, that is, the claw member (28
) (29) was detected by the feedper, but in the case where an elastic material is attached to the tips of the claw members (28) and (29), the difference in the closing amount is small and detection becomes difficult. Therefore, the shape of the catch, such as the diameter and size, may be detected by a pressure sensor provided at the tip of the claw.

In addition, in the case of a left-right asymmetrical article, if the orientation is changed and the article is placed, there will always be a position where the amount of closing of the gripping claws changes when gripped by the gripping claws. In other words, the Y-axis position of the hand relative to the pallet in FIG. 3) is selected and set for each workpiece.

As described above, in the conveyance method according to the present invention, based on the detected amount transmitted to the hand side when the robot grips the article, if the detected amount is different from a predetermined value, the conveyance method is In order to change the posture of the article by moving the seat (rotating, bending, etc.) and transferring it to another conveyor in the normal posture, we need to install a new posture correction device as mentioned at the beginning. There is no need to install one, and the number of steps does not increase. In addition, it is sufficient to provide guide jigs on the pallet to accurately control the position of the articles, and when workers load articles on the pallet, they do not need to consider the orientation of the articles. Since all you have to do is load the items, you can quickly load the items onto the pallet and improve the overall efficiency of the 7 stems.

[Brief explanation of the drawing]

Figure 1 shows the camshaft (
Figure 2 is a side view of the hand part, Figure 3 is a view taken along the line 1-1 in Figure 2, and Figure 4 shows how the electromagnetic switch is installed in the cylinder. FIG. (1)...Robo, (2)...Camshaft (article), (6)...Robot hand, (19)...
- Gripping claw device, (21)... rotary actuator, (28) (29)... claw member, (34)... electromagnetic switch, (P)... pallet, prisoner (B) 0...・Shaft part, (Q... cam part.

Claims (1)

[Claims] Based on the detected amount detected by feedback from the gripped part of the object to the hand side, such as the amount of closing of the gripping claws and the pressure applied to the gripping claws when the hand grips the object,
If the detected amount is different from a predetermined value, it is assumed that the state of the article placed on the pallet is abnormal, and the attitude of the article is changed at the same time as the article is conveyed during the subsequent conveyance process. A method for transporting goods by a robot, characterized by: