JP3211454B2 - Work positioning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for positioning a work, and more particularly to an improvement in the positioning accuracy of the work.

[0002]

2. Description of the Related Art A cylinder block is subjected to deburring after casting. This deburring process is performed using a robot because the same operation is repeatedly performed in an unsanitary environment. In order to perform deburring using a robot, a cylinder block must be fixed at a specific position on fixed coordinates.

[0003] The cylinder block is fixed using a work positioning device. In other words, a conveyor device for transporting a pallet on which a work as a cylinder block is mounted is provided, and the pallet on which the work is mounted is positioned on a line formed by the conveyor device. Hereinafter, the positioning method will be described.

As shown in FIG. 4, four support bases 3 for supporting a work 2 are formed on a pallet 1, and a pair of work reference seats for positioning are provided at the center in the vertical direction in FIG. 4 and 5 are formed. The work 2 is positioned with respect to the pallet 1 by engaging the substantially semi-circular protrusion 7 of the work reference seat 5 with the substantially semi-circular recess 7 of the rib 6 provided at the center of the lower surface of the work 2. . Work 2
Is positioned in the z direction by lifting the pallet 1 on which the pallet 1 is placed by a fixed amount, and the pallet 1 is positioned in the x direction by pressing the pallet 1 against a stopper 9 for positioning one side in the x direction. The pallet 1 is positioned in the y direction by pressing the pallet 1 against a stopper 10 for positioning one side in the y direction. As described above, the pallet is positioned with respect to the fixed coordinates including the x, y, and z axes, and the work is positioned with respect to the fixed coordinates by positioning the work with respect to the pallet.

[0005]

However, since the positioning accuracy of the pallet with respect to the fixed coordinates and the positioning accuracy of the work with respect to the pallet are added as the positioning accuracy of the work with respect to the fixed coordinates, errors in the positioning accuracy of the work are accumulated. As a result, the positioning accuracy deteriorates, and in particular, the positioning accuracy in the left-right direction deteriorates, as indicated by arrows in FIG. On the other hand, in order to increase the processing accuracy of the pallet in order to increase the positioning accuracy of the work with respect to the pallet, pallet types are required by the number of types of the work. In addition, if the accuracy of the pallet is increased, it becomes difficult to set the work.

Accordingly, an object of the present invention is to provide a work positioning method which solves the above problem.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, after a work conveyed on a conveyor and stopped on a pallet at a specific position, the work is fixed together with the pallet. Press the workpiece itself in the transport direction and the horizontal direction perpendicular to the transport direction to position the workpiece itself on the horizontal plane, and finally position The feature is to detect whether the positioning of the work itself is appropriate by detecting the amount of descent when multiple detection pins arranged at specific positions on the horizontal plane are lowered until they come into contact with the work. And

[0008]

When the work is being conveyed on the conveyor together with the pallet, the stop means stops the movement of the work together with the pallet. At the same time, the conveyor is stopped. Thereafter, the work is lifted by a predetermined amount together with the pallet by the vertical positioning means. This allows
This means that the work has been positioned in the vertical direction.
Next, the workpiece is pushed by the transport direction positioning means, and the workpiece is positioned in the transport direction. Next, the workpiece is pushed by a horizontal positioning means perpendicular to the transport direction, and the workpiece is positioned in a horizontal direction perpendicular to the transport direction of the workpiece.

Thus, the work has been positioned at the fixed coordinates. Thereafter, the plurality of detection pins are lowered until they come into contact with the work. If the descending amount of the detection pin is the same as a preset value, it is determined that the positioning of the work is appropriate. If at least one of the descending amounts is different from the set value, it is determined that the work is poorly positioned.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows the configuration of a positioning device for implementing the work positioning method according to the present invention. FIG.
As shown in the approximate center of (b), transport rollers 13 extending in the left-right direction and rotationally driven are provided side by side in a direction perpendicular to the paper surface to constitute a conveyor device 14. Then, the work 2 placed on the pallet 1 is conveyed downward from above in FIG. 1A by the conveyor device 14. A positioning device 15 is provided in the middle of the conveyor device 14.

The structure of the positioning device 15 is as follows. Before describing the structure, for convenience, the transport direction is referred to as x direction, the horizontal direction perpendicular to the transport direction is referred to as y direction, and the vertical direction is referred to as z direction. A table 18 is composed of the four legs 16 and a base 17 provided on the legs 16. Stopping means 19 for stopping the movement of the pallet 1 on the conveyor device 14 and positioning means 20 for pushing the work 2 upward together with the pallet 1 to position the work 2 in the z-direction on the table 18.
Positioning means 21 for positioning the work 2 in the y direction
And positioning means 23 disposed above the conveyor device 14 via the support column 22 and positioning the work 2 in the x direction, and inspection means 24 for inspecting whether the positioning has been properly performed. .

As shown in FIG. 1B, the stopping means 19 includes a pair of lifting rods 25 extending in the vertical direction and a stopper 2 provided to connect the pair of lifting rods 25.
6 and a cylinder (not shown) for driving the lifting rod 25.

The positioning means 20 is attached to a pair of guide cylinders 27 fixed to the base 17, a guide rod 28 inserted through the guide cylinder 27, and a lower end of the guide rod 28 as shown in FIG. With guide rod 2
A stopper 32 for limiting the upward movement of the pallet 8, a lifting platform 29 connected to the upper ends of a pair of guide rods 28, a pallet 1 protruding upward from the upper surface of the lifting platform 29, and between the rollers 13. And a cylinder 31 fixedly mounted on the base 17 between a pair of guide cylinders 27 and having a rod end coupled to a lifting table 29.

As shown in FIG. 3, the positioning device 21 includes a pair of support bases 33 provided so as to sandwich the conveyor device 14 from both sides, a pair of guide cylinders 34 mounted on the respective support bases 33, A guide rod 35 inserted into the cylinder 34, a movable table 36 coupled to the inner ends of the pair of guide rods 35, a pair of push rods 37 provided to protrude from the movable table 36, and a pair of A cylinder 38 is provided between the guide cylinders 34 and fixed to the support table 33 and has a rod end coupled to the moving table 36. Then, the push rod 3 on the left side in FIGS.
In order to position the tip of the guide rod 7, a stopper 39 for limiting the amount of movement of the guide rod 35 is provided on the left guide rod 3
5 is provided only on the left end.

The positioning means 23 is shown in FIGS. 2 (a) and 2 (b).
As shown in FIG. 3, a fixed claw 41 attached to the lower surface of the mounting base 40 on the support column 22, a rotating claw 43 rotatable about a support shaft 42, and an end of a rod 44 at the upper end of the rotating claw 43 And a cylinder 45 mounted on the upper surface of the mounting base 40 while being rotatably connected to the main body.

The detecting means 24 includes one on the left and two on the right below the mounting table 40 in FIG. 2A (FIG. 2B).
Reference) A total of three detection pins 46 and each detection pin 46
And a cylinder 47 (see FIG. 1A) in which a detection pin 46 is attached to the tip of a rod to move the rod vertically.

Next, a method of positioning a workpiece using the positioning device will be described. The work 2 is transported together with the pallet 1 on the conveyor device 14 in the direction shown by the arrow in FIG.
When 5 rises, the pallet 1 hits the stopper 26, and the movement of the work 2 stops. At the same time, the conveyor device 14 is stopped. Thereafter, the rod of the cylinder 31 shown in FIG.
And the support rod 30 are lifted to lift the work 2 together with the pallet 1 by a fixed amount, that is, until the stopper 32 contacts the guide cylinder 27. This means that the work 2 has been positioned in the z direction.

Next, by moving the rod of the left cylinder 38 shown in FIGS. 3A and 3B to the right, the push rod 37 is moved right until the stopper 39 contacts the guide cylinder 34. When the position of the left end of the pallet 1 is determined in this manner, the rod of the right cylinder 38 is moved to the left, and the work 2 is moved through the push rod 37 to the left push rod 3.
Press until it touches 7. This means that the work 2 has been positioned in the y direction.

Next, the cylinder 4 shown in the upper part of FIG.
The rod 44 of No. 5 is moved to the left. Then, the rotating claw 43
Rotates counterclockwise about the pin 42, and the work 2
Is pushed rightward in FIG. 2 (a). Then, the work 2 comes into contact with the fixed claw 41 and is in a state of being sandwiched between the fixed claw 41 and the rotating claw 43. This means that the work 2 has been positioned in the x direction.

As described above, the work 2 is positioned in the x, y, and z directions. To determine whether the positioning is appropriate, the three cylinders 47 above the work 2 are moved. Operate to lower the three detection pins 46. In the present embodiment, since the upper surface of the work 2 is flat, if the amount of drop of the three detection pins 46 is the same, it is determined that the positioning of the work 2 is appropriate. Is determined to be a positioning defect or a dimensional defect of the work 2.

In this embodiment, three detection pins are used. However, the number of detection pins is not limited to three and may be any number.

[0023]

As can be seen from the above description, according to the method for positioning a work according to the present invention, the work itself is directly positioned except in the vertical direction. Work can be positioned accurately. Therefore, there is no need to increase the processing accuracy of the pallet, which reduces the cost of the pallet and facilitates setting of the work on the pallet. In addition, a plurality of types of workpieces can be handled with only one type of pallet.

[Brief description of the drawings]

FIG. 1 shows one embodiment of a positioning device used in a method of positioning a work according to the present invention, wherein (a) is a plan view,
(B) is a front view.

FIGS. 2A and 2B are views for explaining an operation of positioning in a z direction and an x direction according to the present invention, wherein FIG.
Is a front view.

3A and 3B are views for explaining an operation of positioning in the y direction according to the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a front view.

FIG. 4 relates to the description of the operation of the conventional positioning device,
(A) is a plan view, (b) is a front view, and (c) is a right side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pallet 2 ... Work 14 ... Conveyor device 15 ... Positioning device 19 ... Stop device 20, 21, 23 ... Positioning means 24 ... Inspection means 31, 38, 45, 47 ... Cylinder 46 ... Detection pin

Claims (1)

(57) [Claims] After a work conveyed on a conveyor and placed on a pallet is stopped at a specific position, the work is pushed up by a fixed amount together with the pallet to position the work in the vertical direction, and the work is carried out in the conveyance direction and In each horizontal direction perpendicular to the transport direction, the work itself is positioned on the horizontal plane by pressing the work itself, and finally, multiple detection pins arranged at specific positions on the horizontal plane contact the work A method of positioning a work, comprising detecting whether the positioning of the work itself is appropriate by detecting the amount of descent when the work is lowered.