JPS6054205B2 - Pallet circulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used for automatic processing and automatic assembly of articles.
This relates to a pallet circulation device for a so-called transfer machine.

Conventionally, various methods have been considered for this purpose, but one of them, as shown in Figs. 1 to 4, has a relatively simple structure and is suitable for high-speed operation. At least two rollers 2, 3 are provided on the lower surface of each of the plurality of pallets 1, and a plurality of cylindrical cams 5, 5' each having a rotating shaft 4 parallel to the direction in which the pallets travel is arranged below the pallet 1. Then, the rollers 2, 3, 2', 3' clamp the protrusions 6, 6' around the cylindrical cams 5, 5', and move the pallet group between the pallets 1, 1' onto the cylindrical cams 5, 5'. According to the cam curve of
There was something to be moved while positioning.

However, this method requires two or more screw-like cam surfaces on the cylindrical cam, resulting in high processing costs, and the number of rollers on the pallet is often two or more, which has the disadvantage of increasing roller costs and the cost of machining the roller mounting holes on the pallet. Ta. Further position Ho~he, Le~
The linear section of wo is intermittently transferred by the above device, but between positions A to 2 and T to N, as shown in FIG. 3, the push rod 7 driven by one cam (not shown) and a lever 8 driven by another cam (not shown)
The swinging and linearly moving claws 9 and 10 sandwich the rollers of the pallets at positions A and C, and feed the pallets between them to positions 2 and 2, and the detents 11,
It requires two sets of complicated feed claw devices to complete the transfer of the pallet by placing the pallet 12 against the roller of the pallet at the position opening, which makes the machine expensive.
In the case of intermittent transfer in increments of 2 or 113, the cam drive shaft of the feed pawl mechanism needs to be driven at a speed of 112 or 113, which makes the configuration of the device difficult. In a pallet circulation device with a rectangular circulation path as described above, as shown by the long and short arrows on the pallet in Fig. 4, in the straight line section from position H to the straight line from position L to In this case, the front and back of the pallet are viewed from the processing unit placed around the outer periphery of the pallet circulation path, and the direction of movement of each pallet is also reversed, which is generally the case during processing and assembly. The top alignment is poor, and the jig on the pallet is
On the other hand, there was an additional requirement that the pallet should not protrude outward from the periphery of the pallet due to contact with other pallets, making it difficult to use with many restrictions.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned conventional drawbacks and to provide a pallet circulation device that is inexpensive and easy to use.

A pallet circulation device according to an embodiment of the present invention will be described below with reference to FIGS. 5 to 11.

In the figure, 21 and 2" are pallets, 22 and 22" are rollers each attached to the bottom surface of a plurality of pallets, 23 and 23" are rails that guide both sides and the bottom of the pallets, and 24 and 2C are A holding plate that prevents the pallet from floating;
25 is a pin passed through a hole drilled in the pallet to connect the pallets together, 26 is a link plate, and 27 is a retaining metal fitting. In this embodiment, parts 25, 26, and 27 are roller chain joint links. I am using 33. 28, 2' is the rotation axis 29 parallel to the direction of pallet movement.
A cylindrical cam with
2", and the other surface 32, 32"
remains as cast.

The cam surfaces 31, 3'' are shown in a developed view in FIG.
A surface where the cylindrical cam rotation angle is inclined to the rotation axis between 00 and 120 degrees and whose helical lead is equal to the pallet length, and a surface which is perpendicular to the rotation axis 29 between 120 and 360 degrees. Become. Notches 34, 34 are provided at the corners of the pallet 21 where the coupling links 33 are attached, to prevent the pallet from slightly rotating around the pin 25 when it is on a curved section in the circulation route. .

Further, the mounting holes for the pins 25 are drilled at precise positions and with a diameter slightly larger than the diameter of the pins 25 so as not to interfere with the close contact when the pallets 21 are closely connected in a straight line. The overall configuration of the device is as shown in FIGS. 9 to 11, and the circulation path of the pallets is A to B as shown in FIG. (
There is a straight line between 5E and 5E, and below the straight line, right-handed cylindrical cams 28, 2'' on the rotating shaft 29 and left-handed cylindrical cams 35, 35'' on the rotating shaft 34 are arranged.

There is a curved section between C-D and G-H, and there are arc rails 36, 3'', 37, 37'' that guide the pallet, and the inner arc rails 36, 37 guide the rollers on the bottom of the pallet toward the outside of the circle. Press lightly.

38 is a motor that drives a speed reducer 40 via a belt 39, and drives a sprocket 42 on its output shaft 41 via a chain 43 to bearings 45, 46, 4 on a table 44.
The rotating shafts 29 and 34 supported by the sprocket 47
, 48 in the same direction, they are rotated synchronously.

Next, the main points of the operation of this device will be explained. In the straight line between positions A and B, the opposing cam surfaces 31 and 3V of the cylindrical cams 28 and 28'' touch the pallets 2 at both ends of the upper pallet group.
1 and 2" rollers 22, 22" from the outside, and when positioning between the cam curves 1203602, by appropriately adjusting the interval between the cylindrical cams 28, 28". 2. Apply a preload force to the group of pallets in between so that the pallets come into close contact with each other. Since the pallets and rollers are machined with high precision, the pallets 21 and 2
"All pallets between are positioned.0 of the cam curve
Between LE and 1200, the cam curve is
Since the rollers are processed to smoothly move the pallet length while keeping the distance between the centers of 2 and 22'' constant, the pallet group is smoothly transferred by the pallet length and returns to the positioning state again.Position The operation is the same in the other straight section between E and F, but since the cylindrical cams 35, 35'' are twisted in the opposite direction to the cylindrical cams 28, 2'', the rotating shaft 34 is the same as the rotating shaft. When rotated in the same direction as 29, the transfer direction is opposite to that between positions A and B. In the curved section between positions C and D, when positioning the straight section, the inner arcuate rail 36 lightly presses the rollers on the bottom of the pallets outward, creating tension between the pallets.
The pallets are kept stable on the circumference, and when transferring a straight section, the pallets at both ends of the curved section are simultaneously driven along the arc in the same direction by the movement of the two straight sections, so that the pallets are not forced to move. The transfer will take place. The same applies to the other curved section between positions GH. As described above, pallets are circulated throughout the apparatus. As an example of a modified application of the present invention, the cam surface of the cylindrical cam may be provided not on the side surface of the protrusion, but on the wall surface of the cam groove bored around the cylinder, and furthermore, the cam surface of the cylindrical cam may be provided on the wall surface of the cam groove bored around the cylinder, and the lead of the cam curve may be extended to the length of the pallet. As for the curve itself as 112 or 113 of be able to. As described above, the present invention provides one roller for each of the lower surfaces of a plurality of pallets, connects the pallets to form an endless shape, and provides a linear portion of the circulation route through which the connected pallets are transported. In this system, a plurality of cylindrical cams below the pallets are engaged with the rollers to sandwich the group of pallets between them, positioning and transporting them intermittently, and in the curved portion of the circulation path, the pallets are connected. As a result, the pallet transfer device is forcibly transferred by intermittent transfer movement in the straight section, so it is sufficient to have the pallet transfer device only in the straight section, and the overall structure is simple and economical, and the circulation path is There is no problem with the jigs being turned in the opposite direction midway through, and the jigs on the pallet can protrude somewhat from the periphery of the pallet in the direction perpendicular to the direction of travel, and the pallet can be held at 112 or 113 points along its length. Intermittent transfer is also easily possible, making it useful as a transfer machine circulation device.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional pallet circulation device, Fig. 2 is a front view of the same, Fig. 3 is a perspective view showing details of the conventional device, and Fig. 4 is a plan view of the conventional pallet circulation device.
The figure is a schematic plan view of the conventional device, and FIG. 5 is a plan view of a pallet used in the pallet circulation device in an embodiment of the present invention.
Figure 6 is a sectional view taken along line X-X in Figure 5;
The figure is a front view of the main parts of the device, Figure 8 is a developed view of the cam curve of the cylindrical cam, Figure 9 is a plan view of the entire device, Figure 10 is a front view of the same, and Figure 11 is shown in Figure 9. It is a sectional view taken along the YY line. 21,2"...Pallet, 22,22"...
...Roller chain joint link, 28,2'...Cylindrical cam, 29,34
···Axis of rotation.

Claims (1)

[Claims] 1. A roller is provided on the lower surface of a plurality of pallets, a plurality of cylindrical cams are provided below the circulation path through which the pallets are transported, and the cylindrical cams have rotational axes parallel to the direction of travel, and the cam surface of the cylindrical cam is attached to the roller of the pallet. In a pallet circulation device that transports pallets by engaging them, the circulation path is composed of a straight part and a curved part, one roller is provided for each pallet on the bottom surface, and these pallets are connected by a link with a gap. In the straight part of the circulation path, a group of pallets between them is held between the rollers and the pallets themselves by a plurality of cylindrical cams, and the pallets are intermittently positioned and transported, and in the curved part of the circulation path, is a pallet circulation device that is forcibly towed and transferred using links.