JPH0741982B2 - Pallet conveyor - Google Patents

Description

The present invention relates to a pallet conveyor that circulates and transports on a traveling path by pushing one pallet.

[Prior Art] In a conventional pallet conveyor, short passages are overlapped at both ends of a parallel reciprocating path to form a rectangular traveling path, and a pallet arranged on the traveling path is tact-fed by a pusher cylinder in the traveling path. Is configured.

[Problems to be Solved by the Invention] In the conventional pallet conveyor, since the pallets are transferred along the rectangular traveling path along the square motion locus as described above, the pallet on the return traveling path is the forward pallet. The left and right positions are opposite to the traveling direction of. That is, when the articles A and B are respectively placed on the left and right sides of the pallet and run, the pallet does not turn at the leading end of the pallet and follows the square motion locus to move to the return side. Even if the position of is unchanged, the item A is on the right side and the item B is on the left side with respect to the traveling direction.
Further, when moving from the return side end to the going side, the positions of the articles A and B with respect to the traveling direction are returned to the original positions. If such a pallet conveyor is placed in a line including an assembly robot and a transfer robot, the items on the pallet may be displaced left and right in the forward and backward directions, which may cause inconvenience in the operation of grasping the item by the robot hand. . Further, in the conventional pallet conveyor, positioning of the pallet at a specific position is incomplete, which makes it difficult to accurately determine the gripping position by the assembly robot.

It is an object of the present invention to provide a pallet conveyor that can travel in the same left and right position in the traveling direction on both the going and returning sides, and also, at the same time as turning the pallet, positioning at the turning end position is made accurate. The purpose of the present invention is to provide a pallet conveyor that can be applied to peripheral equipment of assembling robots and transfer robots.

[Means for Solving the Problems] In order to achieve the above object, the present invention forms a circulation traveling path by connecting both ends of a reciprocating path with a turning circuit, and a pusher arranged in the reciprocating path is provided with a dog on the back surface of the pallet. Conveyor which is pressed against and travels; a large number of pallets having engaging holes for turning inside the traveling direction; a turning arm attached to the turning center of a turning circuit; a turning for turning the arm 180 degrees Mechanism and pallet positioning means for holding the dogs of the pallet at the end of the turning in at least one of the turning circuits to hold the loading or unloading position of the articles on the pallet; Pin engaging means for inserting an arm side pin into an engaging hole of the pallet stopped by the pallet stopping means, and lowering the arm at the turning end position to disengage the pin. To do.

The pallet positioning means pivotally retracts to the outside of the pusher track when the pusher is pushed, pivotally advances into the track when the pusher is stopped, and comes into contact with the dog of the pallet at the end of turning, and a positioning stopper for rotating the positioning stopper. It is composed of a cylinder. The reciprocating path in the circulation running path has a guide in the center for passing the dog on the back side of the pallet,
A single wheel conveyor for supporting the pallet is arranged on both sides of the guide, and a large number of free bearings or casters for supporting the rotating pallet are arranged in the turning circuit. Further, the dog on the back surface of the pallet has a V-shaped convex portion formed on the rear side in the traveling direction when viewed from the plane, and a V-shaped groove portion that fits into the V-shaped convex portion of the dog is formed on the front side of the pusher.

[Operation] When the turning arm is rotated 180 degrees around the turning center of the turning circuit,
When the pallet is turned, it is stopped accurately by the positioning means. Also, since the pallet is rotated 180 degrees at the end of the reciprocating road, the left-right relationship of the pallet with respect to the traveling direction is always maintained as it is; therefore, when the conveyor is arranged in a line including an assembly robot or a transfer bollot, the work hand It is possible to smoothly carry out the operation of gripping an item. Further, when the pallet is pushed forward, the V-shaped convex portion of the dog and the V-shaped groove of the pusher are fitted to each other, and an automatic check is performed while the pallet is running.

EXAMPLES Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a side view in which a part of the pallet conveyor of the present invention is cut away, and FIG. 2 is a plan view of the same. In the figure, 1 is a pedestal, 2 is a plate arranged in the pedestal 1, 3 is a pallet, 4 is a dog projecting from the back surface of the pallet 3, and 5 is a dog on the forward and return sides formed in the longitudinal direction of the plate 2. , 6 is a single wheel conveyor for supporting pallets arranged on both sides of the guide 5, 7 is a swing arm,
Reference numeral 8 is a turning mechanism, and 9 is a positioning means.

The horizontal rod 1a is horizontally installed in the frame 1, and the plate 2 is attached to the front surface except the guide 5. A center guide unit 23 is provided at the center of the plate 2 to form a forward path 11 and a return path 12 for the pallets which are parallel to each other, and both ends thereof are turned circuits 13, 14.
To form a circulating road. As described above, the guides 5 for guiding the dogs 4 of the pallet are provided at the center of the reciprocating and returning paths, and two single wheel conveyors 6 are provided on both sides of the guides 5. A large number of free bearings or casters 15 are arranged in the rotating circuits 13 and 14.

A rodless cylinder type pushing mechanism 16 for pushing the pallet 3 is provided at the downstream position of the reciprocating paths 11, 12. In the pushing mechanism 16 of the illustrated example, a movable body 18 having a built-in permanent magnet is attached to a cylinder tube 17, and the movable body is guided by a guide rod 19 to perform linear reciprocating motion. When the movable body 18 moves forward, the pusher 20 on the upper side of the movable body is fitted into the dog 4 on the pallet 3 side to push the pallet forward (FIGS. 4 and 8).

As shown in FIGS. 2 and 5, the dog 4 has a pentagonal shape in which a V-shaped convex portion 21 is formed on the rear side in the traveling direction as seen from the plane, and the pusher 20 facing this is the front side of the dog 4 on the front side of the traveling direction. The V-shaped convex portion 21 is formed in the V-shaped groove portion 22 so that the dog 4 is pushed forward by the operation of the pushing mechanism 16 so as to perform self-centering.

As shown in FIG. 2, pallet stopping means 25 is provided at the end of the runways 11 and 12 on the going side and the returning side. The stopping means 25 is for temporarily stopping the pallet 2 at the end of each of the running paths 11 and 12. As shown in FIG. 5 and FIG. 6, a stopper is attached to the piston rod end of the thin cylinder 26.
27 is mounted and a guide rod 28 is provided in parallel with the piston rod. When the thin cylinder 26 is actuated, the stopper 27 rises above the purse line in the turning circuits 13 and 14 to bring the front end of the pallet 3 into contact, and when the thin cylinder 26 contracts, the stopper 27 descends below the purse line.

A large number of pallets 3 arranged on the traveling path have 21 engaging holes 29 for turning near the inner corners in the traveling direction, and the turning centers of the turning circuits 13 and 14 can turn 180 degrees. The arm 7 is attached, and two pins 31 are projected from the tip of the arm (FIGS. 5 and 7).

The swing arm 7 includes a swing gear 36 fixed to the swing shaft 30,
A rack 37 that meshes with the swivel gear 36 and a swivel mechanism 8 including a power cylinder 38 for driving the rack drive the swirl circuit.
Turn 180 degrees. A detection piece 47 is provided at the tip of the rack 37,
Detectors (proximity switches) 48 and 49 for turning confirmation are arranged at the origin of the rack tip and at the stroke end (5th position).
Figure). Further, on the upper surface of the revolving gear 36, the revolving arm 30
Thin cylinder 32 that moves up and down to form pin engaging means
And a pair of rods 33 that guide the lifting and lowering of the arm. In this thin cylinder 32, the arm at the start of rotation is lifted to insert the pin 31 on the arm side into the engagement hole 29 of the pallet 3 stopped by the pallet stopping means 25, and the arm is lowered at the end of rotation. It is for removing the pin 31. It should be noted that the one accommodation cylinder 39 of the guide rod 33 is provided.
Secure the contact piece 40 to the
A stopper cushion 41 is provided at the ends of 11 and 12 to absorb a shock at the turning end when the pallet 3 is engaged and the arm turns.

Further, the pallet positioning means 9 is provided at the turning end position in at least one of the turning circuits (the right turning circuit 14 in FIG. 2).
To provide. This means comprises a stopper 42 that comes into contact with the dog 4 of the pallet 3 swung by the swivel arm 7, and a stopper rotation cylinder 43. Positioning stopper 42
Is supported by a bracket 44 provided on the side of one of the pushing mechanisms 16, and the piston rod 45 of the rotating cylinder 43 is connected to the opposite side of the stopper. As is apparent from FIG. 5, the stopper 42 pivots and retreats out of the track of the pusher 20 by the contraction of the cylinder 43 so as not to interfere when the pusher 20 is advanced, and when the pusher 20 stops at the stroke end, As shown by the solid line in FIG. 5, it pivotally advances into the track and comes into contact with the dog 4 of the pallet at the turning end. The pallet 3 stopped by the positioning stopper 42 is an industrial robot or a transfer robot (not shown).
Accurately holds the loading and unloading positions of items on the pallet. Note that FIG. 5 shows the plate 2 and the casters so that the arrangement of each part of the swivel part can be easily understood.
Illustration of 15 is omitted.

Next, the operation will be described. A large number of pallets 3 arranged on the reciprocating path 11 and the return path 12 are cyclically moved by pushing one pallet at a time by the operation of the pushing mechanism 16. On the pallet, a jig (not shown) such as a stand or a socket is used to correctly place the item at a predetermined position. The position where the item is placed serves as a reference point when the industrial robot or the transfer robot grips the item. That is, at the turning end of the turning circuit 14 on the right side (Figs. 2 and 5) and on the return path.
When the pallet 3 is positioned at the most downstream position of 12, the jig center on the pallet 3 is used as the coordinates at the time of the grip operation.

Each pallet 3 is supported by two single-wheel conveyors 6 arranged in the reciprocating paths 11 and 12, and is stationary with the dog 4 inserted in the guide 5. When the pusher 20 is moved forward by the operation of the pushing mechanism 16 in this state, the V groove portion 22 formed on the front side of the pusher 20 engages with the V-shaped convex portion 21 on the back surface of the pallet at the most downstream position of the forward and backward paths. It is pushed while self-centering. Due to this pushing, the pallets on the upstream side are simultaneously pushed to move a distance corresponding to one pallet. The earliest pallet is the stopper 27 of the pallet stopping means 25 provided in the turning circuits 13 and 14 as shown by the chain line in FIG.
Stop at.

With respect to the pallet 3 stopped by the stopper 27 that has risen above the perspective line by the operation of the pallet stopping means 25, the thin cylinder 26 is driven to raise the swing arm 30 of the swing mechanism 8 by a predetermined stroke (for example, 20 to 40 mm). , The pin 31 near the tip of the arm is engaged with the engaging hole 29 provided in the corner inside the pallet to temporarily integrate it. Then, the thin cylinder 60 is returned to lower the stopper 27, and then the power cylinder 38 of the turning mechanism is driven to rotate the turning gear 36 by 180 degrees to turn the pallet 3. The rotating pallet is supported by free bearings or casters 15 and stably rotated while maintaining a horizontal plane. At the turning end, the first piece 40 hits the stopper cushion 41 to absorb the shock and stop. Whirl circuits are formed at both ends of the round trip, while
In the figure, since the left and right turning circuits 14 have the positioning means 9, they are positioned at the same time as the turning circuit 3. That is, as shown in FIGS. 2 and 5, since the positioning stopper 42 is advanced into the movement locus of the pusher 20 and the dog 4 by the operation of the rotation cylinder 43, the dog 4 in the pallet at the turning end is moved to the above-mentioned position. The stopper 42 is brought into contact with the stopper 42 and stopped in the positioned state.

Robots are used to grab and stack or unload items on the pallet while the pallet is in the position state. For example, an article (particularly a work piece) is placed on a jig on a pallet near the downstream of the outward path 11 in FIG. 2, the article is picked up at the positioning position, and then another article or a processed work piece is treated in the same manner. The pallet, which is placed on a tool and finished with these operations, is used to take out the machined work at a position moved near the turning circuit 13 on the left side, upstream of the return path 12. Since the left-right positional relationship of the pallet does not change with respect to the traveling direction of the conveyor in any of the reciprocating paths, it is not necessary to shift the work handling coordinate when the robot is introduced.

In the above work, when the product loading and unloading at the positioning position is completed, the rotary cylinder 43 is actuated to the return side to move the positioning stopper 42 to the track of the pusher 20 as shown by the chain line in FIG. Prepared for the next turning of the pallet by turning it to the outside. Further, during handling of the product at the positioning position, the pin 31 of the swing arm 7 is kept fitted in the pallet side engagement hole 29 so as not to be displaced. After this work is completed, the thin cylinder 32 is returned to unpin the pin 31, the power cylinder 35 is returned, and the rack 37 is pulled back. When the rack is pulled back, the revolving gear 35 reverses 180 degrees and the revolving arm 7 returns to the position shown by the solid line in FIG. At the return end, the hitting piece 40 fixed to the upper part of the turning gear 36 hits the stopper cushion 41 on the turning start end side (the upstream end of the outward path 11) to absorb the shock and stop.

By repeating the above operation and sequentially feeding the pallet 3 in sequence, the goods are accurately handled at the positioning position.

EFFECTS OF THE INVENTION As described above, according to the present invention, when the turning arm is rotated 180 degrees around the turning center of the turning circuit, the positioning means stops the turning end of the pallet, so that the articles on the pallet on the conveyor are stopped. Accurate loading and unloading. Also, since the pallet is rotated 180 degrees at the end of the reciprocating road, the left-right relationship of the pallet with respect to the traveling direction is always maintained as it is. Therefore, when the conveyor is placed on the line including the assembly robot and the transfer robot, the work hand goods There is an effect that the grasping operation can be performed smoothly.

[Brief description of drawings]

FIG. 1 is a side view showing a part of the pallet conveyor of the present invention in a cutaway manner, FIG. 2 is a plan view of the same, and FIG. 3 is II of FIG.
A sectional view taken along line I-III, FIG. 4 is a sectional view taken along line IV-IV in FIG. 2, FIG. 5 is an enlarged plan view showing a swivel unit and a positioning device, and FIG. 6 is an enlarged side view of pallet stopping means. , FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG.
FIG. 8 is an enlarged side view of the pusher. 1 ... Stand, 2 ... Plate, 3 ... Pallet, 4 ...
Dog, 5 ... Guide, 6 ... Single wheel conveyor, 7 ... Swing arm, 8 ... Swing mechanism, 9 ... Positioning means, 11 ... Forward path, 12 ... Return path, 13, 14 ... Turning circuit , 15 …… Caster, 16 …… Pushing mechanism, 20 …… Pusher, 21 …… V-shaped convex part, 22 …… V groove, 25 …… Pallet stopping means, 27 …… Stopper, 29 …… Engaging hole , 30 …… Swivel axis, 31 …… Pin, 35 …… Swivel mechanism, 36 …… Swivel gear, 37
...... Rack, 38 …… Power cylinder, 40 …… per piece, 41
…… Stopper cushion, 42 …… Positioning stopper.

Claims (7)

[Claims] 1. A conveyor for connecting both ends of a reciprocating path with a turning circuit to form a circulating traveling path, and pushing a pusher arranged in the reciprocating path against a dog on the back surface of a pallet to move; A large number of pallets provided with engaging holes for turning; a turning arm attached to the turning center of a turning circuit; a turning mechanism for turning the arm by 180 degrees; and a pallet at the end of turning in at least one turning circuit. Pallet positioning means for holding the loading or unloading position on the pallet by bringing the dog into contact with the pallet; and an arm at the engaging hole of the pallet stopped by the pallet stopping means by raising the arm at the turning start end. And a pin engaging means for disengaging the arm by lowering the arm at the turning end position. 2. The swivel mechanism comprises a swivel gear for fixing an arm, which is provided on a swivel center axis, a rack engaging with the swivel gear, and a power cylinder for driving the rack. Pallet conveyor. 3. A pallet stopping means for temporarily stopping a pallet immediately before advancing into a turning circuit is provided at each upstream end of the reciprocating path, and the pallet stopping means moves up and down with respect to a pallet purse line in the turning circuit. The pallet conveyor according to claim 1, wherein the pallet conveyor comprises a stopper and a stopper lifting cylinder. 4. A pallet positioning means includes a positioning stopper that pivotally retreats out of a pusher orbit when the pusher is pushed forward, pivotally advances into the orbit when the pusher is stopped, and abuts against a pallet dog at a pivot end end. The pallet conveyor according to claim 1, wherein the pallet conveyor comprises a rotating cylinder of a positioning stopper. 5. The pallet conveyor according to claim 1, wherein the pin engaging means is a thin cylinder fixed to the upper surface of the revolving gear and moving up and down the revolving arm. 6. The dog on the rear surface of the pallet has a V-shaped convex portion formed on the rear side in the traveling direction when viewed from the plane, and a V-groove portion fitted on the V-shaped convex portion of the dog on the front side of the pusher. A pallet conveyor according to claim 1. 7. The reciprocating path has a guide through which a dog on the back side of the pallet passes in the center, single-wheel conveyors for supporting the pallet are arranged on both sides of the guide, and a rotating circuit supports the rotating pallet. The pallet conveyor according to claim 1, wherein a large number of free bearings or casters are arranged.