JPH045228Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a pallet conveying device for use in assembling parts, etc. to lightweight articles such as video circuit boards by robot work.

Prior Art and its Problems The work of assembling a large number of parts onto lightweight articles such as circuit boards and base bodies to be incorporated into electrical machines, measuring instruments, etc., involves placing the lightweight articles on a pallet and attaching them to the underside of the pallet so as to be able to rotate freely. In many cases, a pallet conveying device is used in which the traveling and stopping of pallets is controlled by bringing a driven roller into frictional contact with a drive rotating shaft provided along a pallet traveling guide rail.

Such a pallet conveying device for lightweight articles, as disclosed in Japanese Patent Publication No. 52-45568, for example, has the rotational axis of the driven roller obliquely intersecting the drive rotational axis to reduce the friction between the driven roller and the drive rotational shaft. Pallets are transported by transmission.

When the axis of rotation of the driven roller and the axis of rotation of the drive are parallel, even if the axis of rotation of the drive is rotating, the driven roller only rotates in the reverse direction and the pallet is stopped without being driven forward.

FIG. 11 is a perspective view of such a pallet conveying device, in which a pallet 1 runs in the direction of arrow A on two rails 3 and 3' supported on a pedestal 2,
The entire assembly work is completed by repeatedly stopping at a predetermined assembly work position, starting when the assembly work is completed, and stopping again at the next assembly work position.

On the pedestal 2, there is a pallet conveyance drive shaft 4 arranged parallel to the rails 3, 3', and the drive shaft 4 is pushed against the circumferential surface of a driven roller 5 rotatably mounted on the lower surface of the pallet 1 shown in FIG. When the axis of rotation of the driven roller 5 is oblique to the axis of the drive shaft 4, the pallet 1 is driven forward, and when the axis of rotation of the driven roller 5 is parallel to the axis of the drive shaft 4, the pallet 1 is driven forward. Pallet 1 is stopped.

A swinging work plate 6 is fixed to the driven roller 5, and the swinging work plate is interlocked and connected to levers 8, 8' pivotally connected to the front and rear parts of the pallet via interlocking rods 7, 7'.
The rotation axis of the driven roller 5 is obliquely intersected with the axis of the drive axis 4 by the spring 9 of the swing operation plate 6, and the lever 8,
8' is pivoted so as to protrude forward and rearward from the front and rear parts of the pallet, respectively.

Cam pins 10, 10' are protruded from the swing operating plate 6, a stopper pin 11 is protruded from the lower surface of the pallet near the cam pin 10, and a lock pin 12 is protruded from the lower surface of the side of the pallet. .

Wheels 13 rolling on rails 3, 3' are provided at the corners of the lower surface of the pallet 1, and a pair of guide rollers 14, 14' for holding the rail 3 are installed at the front and rear of one side of the lower surface of the pallet. is guided along the rails 3 and 3'. At the front and rear of the pallet 1, there are push members 15, 1 that push and retract levers of adjacent pallets to rotate the driven rollers 5.
5' is provided protrudingly. .

A pallet stop positioning device 6 is provided between the rails 3 and 3' and operates in cooperation with a cam pin 10 and a stopper pin 11 that project from the pallet.

The details of the pallet stop positioning device 16 are explained in the 13th section.
As shown in the figure.

That is, the stopper pin 1 that appears and retracts on the movement path of the stopper pin 11 protruding from the lower surface of the pallet by the cylinder device 17 operated by a command signal.
The cam pin 10 protrudes from the rotation operating plate 6 of the driven roller 8 and the driven roller. The rotation axis of drive shaft 4
A stop actuating plate 20 having a cam surface 19 that pivots to the nearest position parallel to the axis of rotation of the pallet is mounted, and a spring 21 (Fig. A pallet stop positioning plate 22 is pivotally attached to the pallet stop positioning plate 22, which is rotationally biased by When the stopper pin 11 is pushed open and collides with the stopper 18, the cam surface 23 returns to its original position by the spring 21, and the stopper pin 11 is pressed between the stopper 18 and the stopper 1.
A cam surface 24 is formed to press 1 laterally.

Therefore, as shown in FIG. 14, the stopper pin 11 is pressed between the stopper 18 and the cam surface 24, and the cam surface 19 of the stop operation plate 20 moves the cam pin 10 of the swing operation plate 6 to the driven roller. The pallet 1 is not pushed until the axis of rotation of the pallet 5 is parallel to the axis of rotation of the drive shaft 4, but is pushed so that it is in the closest parallel position, so the pallet 1 receives a slight forward driving force from the drive shaft 4. transmitted and therefore the stopper pin 1
1 is always kept pressed against the stopper 18, and the pallet does not run backwards.

The mechanism described above is for stopping the pallet 1 while applying a weak forward driving force to the pallet 1. Accurate positioning of the pallet is achieved by using the V-claw stopper 26 in Fig. 13 with an air cylinder (Fig. (not shown), the V-groove 25 is pressed against the lock pin 12 (see Fig. 12), and the pallet 1 is moved through the guide rollers 14, 14' on the front side.
This is done by pressing the guide rail 3' against the guide rail 3'.

FIG. 10 is a simplified view of the pallet positioning mechanism described above, omitting the mechanism for stopping the driven roller 5 with its axis of rotation substantially parallel to the axis of rotation of the drive shaft 4. V-claw stopper 3
1 presses the positioning roller 32 (corresponding to the lock pin 12 in FIG. 12), so that its center becomes the reference position in the front-rear direction of the pallet 30, and the guide rollers 33, 33' press against the rail 34, so that the pallet 30 Positioning in the width direction will also be performed.

By the way, this palette 30 has two
Normally, book positioning pins 35 and 36 are provided in a protruding manner, and another pallet (not shown) with holes in corresponding positions is placed on the pallet. (In this case, the pallet 30 is called the primary pallet, and the pallet placed on top of it is called the secondary pallet. Note that it is also possible to directly drill holes in the workpiece and place it on the (primary) pallet 30 without using the secondary pallet. However, in this case, since the positioning pins 35, 36 and the positioning roller 32 are provided separately, the stopping accuracy of the positioning pins 35, 36 is limited to the machining of dimensions a, b, c, and d in Fig. 10. There were problems in that it depended on accuracy, and each dimension was easily affected by temperature changes (the degree of expansion differed depending on the temperature in summer and winter, for example).

Means for Solving the Problems The present invention is based on a machine that is loaded with workpieces or secondary pallets and travels under the guidance of rails and guide rollers.
A reference-side positioning pin that serves as a stop position reference for the primary pallet and engages with the work or the secondary pallet on the upper surface of the next pallet, and a guide-side positioning pin that simply engages with the work or the secondary pallet; The lower surface of the primary pallet has a positioning guide that is integrated with the reference side positioning pin and is pressed in the direction of the rail at the stop position of the primary pallet, and the guide side positioning pin rotates with respect to the primary pallet. The above-mentioned problem has been solved by a configuration in which the rotary member is provided at an eccentric position so as to be able to rotate.

Function In this invention, the reference side positioning pin and the positioning guide are attached to the pallet as one body, and
The guide side positioning pin is also attached to the pallet, so if the positioning guide is fixed by some means for positioning, its fixed position will match the stop position of the reference side positioning pin, so it can be achieved with extremely high accuracy with normal machining. Accurate positioning is possible, and it is not easily affected by temperature changes.

According to the present invention, the guide side positioning pin is provided at an eccentric position of the rotating member that is provided so as to be able to rotate with respect to the primary pallet, so that the guide side positioning pin is relative to the reference side positioning pin. Angular position can be corrected accurately and easily.

Embodiment An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows a positioning mechanism using a V-claw stopper 31, and a guide roller 33,
A reference side positioning pin 37 and a guide side positioning pin 38 protrude from the upper surface of the pallet 30 which travels while being regulated by 33'.

As shown in FIG. 2, the reference side positioning pin 37
The positioning guide 39 and the positioning guide 39 have an integral structure and are fixed to the pallet 30 with a lock nut 40.

Positioning guide 39 protruding from the bottom of the pallet
Positioning is performed by being pressed by a V-claw stopper 31 that operates at a stopping point.

Therefore, the reference side positioning pin 37 can be positioned without error in both the front-rear direction (X-X) and the width direction (Y-Y).

FIG. 3 shows how to attach the secondary pallet 50 on the (primary) pallet 30.
1, the secondary pallet 50 is fitted. The mounting hole for the reference side positioning pin 37 may be a normal round hole. In this way, accuracy in the Y-Y direction, which is the width direction, is not required, and the reference line B-B with respect to the A-A axis in the X-X direction connecting the centers of the front and rear guide rollers.
Angle α of the axis (line connecting the centers of both positioning pins)
It only depends on the accuracy of (see Figure 1).
Furthermore, if only the angle α is affected by changes in the temperature of the pallet, it is not easily affected.

Next, a method for accurately setting the angle α will be described. First, FIGS. 4a and 4b and FIG. 5 show a method for adjusting the position of the guide side positioning pin 38 using an eccentric boss method.

As shown in FIG. 5, the guide side positioning pin 3
8 is the reference line B by a distance from the reference side positioning pin 37
-B, the eccentric boss (rotating member) 38' is rotated, and the positioning pin setting jig 60 is rotated.
The guide side positioning pin 38 can be held so as to align with the reference line B-B while looking at the dial gauge 61 incorporated in the guide side positioning pin 38. After that, secure with lock nut 38''.

Of course, this is done by setting the lower line of the setting jig 60 in FIG. 5 along the reference line A-A. Set in advance so that

The jig block 62 can move along the guide grooves 63, 63'.

If the eccentricity is 0.1 to 0.2 mm, this method can also achieve an accuracy of ±20 μm.

Figures 6a and b are methods that do not use eccentric bosses,
Guide rollers 33A, 33 with variable eccentricity
By adjusting the amount of eccentricity of A', the inclination of the pallet can be corrected so that the guide side positioning pin 38 is placed on the reference line B-B.

By the way, the present invention can be used not only for the two-dimensional positioning described above but also for three-dimensional positioning.

Figures 7 to 9 show a pallet push-up positioning mechanism for this purpose, and the reference side positioning pin 77 and guide side positioning pin 78 are both positioning guides 77' and 77 at the lower part of the pallet.
8' and is attached to the pallet 70. The mounting method may be similar to that shown in FIG.

It is assumed that the drive mechanism of the pallet conveying device in this case is such that the pallet stops when it hits an obstacle.

When the stopper 72 is projected forward in the traveling direction of the pallet 70 by the air cylinder 71, the progress of the pallet is stopped, and the piston rod 81 of the air cylinder of the lifting mechanism 80 is raised, and the vertical direction regulating stoppers 82, 82 provided on the side surfaces of the pallet are raised. The reference side push-up guide block 83 and the guide side push-up guide block 84 raise the pallet 70 until the pallet collides with the pallet 70.

The push-up guide blocks 83 and 84 have guide holes 8 into which the positioning guides 77' and 78' are fitted.
3' and 84' are respectively provided, and it is preferable that the guide hole 84' of the guide side block 84 is an elongated hole as shown in the figure. Of course, the reference side guide hole 83' may be a round hole.

If the upper ends of these holes are tapered as shown, their alignment function will allow the pallet to be brought to the position of the guide block even if there is a slight misalignment.

With the above configuration, the positioning pin 77 can be
The guide side positioning pin 78 can be positioned without error in the X direction.

Furthermore, it is a matter of course that by pressing the pallet 70, positioning can be performed in the vertical direction without error.

For installation of the secondary pallet (not shown),
This can be done as shown in FIG.

The push-up assisting blocks 85, 85' are used as necessary when the pallet size is large. And push-up guide blocks 83, 84
By supporting the base plate 86 with springs 87, the pallet can be fixed without play.

Note that 88 is a guide bearing.

Effect of the invention 1: High-precision positioning (repetitive positioning accuracy of ±20 μm) is possible with normal machining accuracy.

2. Not easily affected by temperature changes.

3. The mechanism is simple.

4. Normal machining accuracy is sufficient, so machining with special machine tools is not required, and inspection is not particularly required, so machining costs are low. And since the positioning pin itself is accurately positioned,
It is not affected by the accuracy of mounting on the pallet.

5. Since it is less affected by temperature changes, there is no need for temperature control during processing, so processing costs are low.

Also, during use, the positioning accuracy will not be affected by the surrounding environment, and therefore the quality of the product will be stable.

[Brief explanation of the drawing]

Figure 1 is a plan view of the positioning mechanism using the pallet of the present invention, Figure 2 is a sectional view of the reference side positioning pin and positioning guide installed, Figure 3 is a plan view showing how to install the secondary pallet, Figure 4 a, b
5 is a plan view showing the method of adjusting the guide side positioning pin; FIGS. 6 a and b are plan views showing before and after correcting the pallet inclination using the eccentric guide roller; Figure 7, Figure 8, Figure 9
The figures show a plan view, a front view, and a side view of the pallet push-up positioning mechanism, respectively. Fig. 10 is a plan view showing the positional relationship of the positioning pins on the conventional pallet surface, and Fig. 11 shows the conventional pallet conveying device. A perspective view, Figure 12 is a bottom perspective view of the pallet, Figure 1.
FIG. 3 is a perspective view of a conventional pallet positioning mechanism, and FIG. 14 is a plan view of a conventional pallet stopping mechanism. 30, 70... Pallet, 37, 77... Reference side positioning pin, 39, 77'... Positioning guide.

Claims (1)

[Scope of utility model registration request] A reference side positioning pin is provided on the upper surface of the primary pallet loaded with a work or a secondary pallet and travels under the guidance of rails and guide rollers, which serves as a reference for the stopping position of the primary pallet and which engages with the work or the secondary pallet. A guide-side positioning pin with which the work or the secondary pallet simply engages is provided, and the pin is integrated with the reference-side positioning pin on the lower surface of the primary pallet and is pressed in the direction of the rail at the stop position of the primary pallet. A pallet conveying device comprising a positioning guide, wherein the guide-side positioning pin is provided at an eccentric position of a rotating member that is rotatable with respect to the primary pallet. .