JPH0124101B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pallet direction changing device which is provided with a linear feed index cam and whose purpose is to change the running direction of a pallet at right angles.

In the conventional indexing mechanism in which pallets are index-fed using a feeding rod, the mechanism for returning the pallets from the last station and transferring them to the conveyor is complicated, leading to high equipment costs.
Further, a structure in which pallets are circulated in a rectangular ring shape requires a driving source for each straight line, and also requires a pallet transfer device at each corner.

However, if the pallet travel path of the present invention is laid out in a rectangular ring shape, it becomes possible to arrange work stations around the entire circumference of the travel path, and it is not necessary to install special equipment for returning or transferring the pallets. There are some characteristics such as no. Therefore, the present invention satisfies the above-mentioned need by movably providing a guide member for regulating the traveling direction of the pallet at the corner portion of the travel path, thereby allowing the pallet to move smoothly around the right-angled corner portion.

In the pallet of this invention, a linear feed index cam consisting of two plate cams is fixed to a drive shaft, and the drive shaft is rotated by a motor built into each pallet. The linear feed index cam obtains a driving force for self-propulsion, but in order to change the traveling direction of the pallet to a right angle at the corner of the travel path, a moving guide is installed at the end of the fixed guide member (horizontal wall). The members are connected and the movement guide member is moved while the pallet is stopped at a corner.

That is, to explain the present invention in terms of an embodiment, in FIG. 1, a pallet traveling path is formed by frames 2, 2a which are placed opposite each other at a predetermined interval. As shown in FIG. 1, rollers 3 and 3a for supporting the pallet 1 are installed horizontally at predetermined intervals inside the upper part of the frames 2 and 2a of the running path, and support walls 4 of the cam followers 5 and 6 are installed inside the frame 2. are horizontally protruding, and cam followers 5 and 6 are attached to the upper and lower surfaces of the support wall 4 so as to be rotatable about vertical axes, respectively, and the cam followers 5 and 6 are installed in series at predetermined intervals in the longitudinal direction of the support wall 4, respectively. At the same time, cam followers 5 and 6
are arranged half a pitch apart from each other. Next, a horizontal wall 7 is horizontally projecting from the inside of the frame 2a, and the projecting end surface (vertical surface) of the horizontal wall 7 forms a contact guide surface for the roller 9 of the pallet drive shaft 8.
In an actual configuration, the guide surface can be formed smoothly and with high precision by fixing, for example, a metal rail.

Pallet guide rollers 10 are mounted on the upper end surface of the frame 2 at equal intervals in the longitudinal direction so as to be freely rotatable around a vertical axis. The pallet 1 has a drive shaft 8 rotatably installed vertically in the center of a pallet base plate 16, and plate cams 11, 12 in the middle of the drive shaft 8.
are fixed in parallel, and a guide roller 9 is rotatably attached to the lower end of the drive shaft 8. A motor 13 is installed on the pallet board 16, and a bevel gear 14 fixed to the shaft of the motor 13 and a bevel gear 15 fixed to the upper end of the drive shaft 8 are engaged with each other. In the embodiment described above, the rollers 3, 3a were installed inside the upper ends of the frames 2, 2a, but instead of the rollers 3, 3a, rails were laid horizontally, and the rails were rolled on the rails to the lower surface of the pallet board 16. Similar effects can be obtained even if a guide roller is provided or if the guide roller is slid on a rail.

Next, the operation of the pallet will be explained based on the above embodiment. As explained with reference to FIG.
The pallet 1 is supported by the pallet a, and the left and right movement of the pallet is controlled by the contact between the cam followers 5 and 6 and the plate cams 11 and 12, and the contact between the roller 9 attached to the drive shaft 8 and the side wall 7. Since rotation of the pallet is prevented by restraining it and bringing the side surface of the pallet into contact with the guide rollers 10, the pallet 1 is installed in such a state that it can only move straight along the frames 2, 2a. Then, if you start the motor 13,
The drive shaft 8 is rotated via the bevel gears 14 and 15, and the plate cams 11 and 12 are rotated by the rotation of the drive shaft 8.
rotates.

Next, FIG. 2 shows the relationship between the rotation of the plate cam and the movement and stopping of the pallet. In this figure,
, respectively indicate a state in which the pallet is in the middle of stopping, a state in which the pallet begins to move from a stop, a state in the center of the index, and a state in which the pallet has finished moving to a stop. A in FIG. 2 shows the relationship between the pallet 1 and the cam, and the positional relationship between the pallet 1 and the guide roller 10.

FIG. 3 is an explanatory diagram of the operation in which the pallet 1 is stopped at a corner and then sent out onto a travel path in a right angle direction.

2 and 3, the pallet 1 moves from the right side of the figure in the direction of arrow 18 while repeatedly stopping and moving due to the rotation of the drive shaft 8 until it reaches a corner where the direction should be changed.

At the corner, the running path in the right angle direction, the horizontal wall 7a, the cam followers 5a, 6a, and the guide roller 10a are arranged as shown in FIG. The position of the first cam follower 5a at the corner is shifted by half a pitch in the right angle direction. As is clear from Figure 2, the third
Index scums 11, 12 at the corners of the figure
The angular position indicates the position where the allocation is just completed and pallet 1 begins to stop.

In order for the pallet 1 to stop at a predetermined position at the corner, the front edge of the horizontal wall 7 must protrude beyond the horizontal wall 7a of the running path in the perpendicular direction by more than the radius of the roller 9, as shown in FIG. The corner guide member 20 is installed for this purpose, and while the pallet 1 is stationary, the corner guide member 20 is installed so that the horizontal wall 7a in the right angle direction as shown in FIG.
Instead of protruding the corner guide member 21, it is retracted as shown in FIG. 4 so as not to obstruct the movement of the roller 9 in the right angle direction.

When the pallet 1 arrives at the corner shown in FIG. 3, it begins to stop, and this stopping position is also exactly the stopping position with respect to the cam followers 5a, 6a in the perpendicular direction. When the drive shaft 8 rotates further and the plate cams 11 and 12 reach the positions of the plate cams 11a and 12a, the stop of the pallet 1 ends and the pallet 1 moves in the direction of the arrow 18a along the travel path in the right angle direction. .

In FIG. 3, the positions of the plate cams 11 and 12 where the corner cams start to stop and the positions of the plate cams 11a and 12a where the movement in the right angle direction starts (stops stop) are compared to the case where there is no running path in the right angle direction. ,exactly
It is located 90 degrees ahead. That is, the index scum shown in Figures 2 and 3 has an index angle of 120° and a retention angle of 120°.
Since it is 240°, the stopping angle at the corner is 240° − 90° =
It is 150°.

Therefore, in the case of FIG. 3, the pallet remains stationary while the drive shaft 8 rotates 150 degrees, so if the moving guide member 21 is protruded during this period and then the moving guide member 20 is pulled back one by one, the pallet at the corner can be moved. The change in direction of travel of No. 1 is performed smoothly.

In the above explanation, the cam was explained when the pallet is moved by one pitch of the cam follower (P in Fig. 2) with one revolution of the drive shaft 8, but a half-rotation type linear feed index as shown in Fig. 4 is used. A cam can also be used to index every half pitch.

That is, according to the present invention, a pallet equipped with a drive motor and a linear feed index cam is installed on a circular traveling path consisting of a linear traveling path, and guide members are movably provided at the corners of the traveling path. This has the effect of making it possible to smoothly and stably change the traveling direction of a pallet containing a self-propelled motor. However, even when changing direction, the movement is based on the motion characteristics of the linear feed index cam, so there are no unstable factors such as inertia, and there is no need to install a shock absorber or the like.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a traveling path and a pallet according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the pallet traveling by the rotation of the plate cam, and Fig. 3 is a pallet at the corner section extended from Fig. 2. FIG. 4 is an explanatory diagram of the movement direction change, FIG. 4 is an explanatory diagram of the entrance and exit of the roller guide member at the corner, and FIG. 5 is an explanatory diagram of the square annular traveling path. 1... Palette, 2, 2a... Frame, 3, 3a
... Roller, 4... Support wall, 5, 6, 5a, 6a... Cam follower, 7, 7a... Side wall, 8... Drive shaft, 9... Roller, 10... Guide roller, 11, 12, 11a,
12a... Plate cam, 13... Motor, 14, 15... Bevel gear, 16... Pallet board, 17... Arrow,
18, 18a...arrow, 20, 21...movement guide member.

Claims (1)

[Scope of Claims] 1. In an apparatus in which pallets equipped with a drive motor and a linear feed index cam are installed on a straight running path, when changing the traveling direction of the pallets, a 1. A pallet direction changing device characterized by movably installing guide members perpendicular to each other for restraining directions. 2. The pallet direction changing device according to claim 1, wherein the traveling path is constructed by arranging in parallel a cam follower corresponding to a support member for the pallet board, a guide member, and a linear feed index cam. 3. The pallet direction changing device according to claim 1, wherein the pallet has a drive shaft provided with a linear feed index cam installed vertically on the pallet board, and the drive shaft is driven by a motor fixed to the pallet board. .