JPS6250376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention transports and circulates a plurality of pallets using a chain or the like, and a work unit is placed in the transport path to perform work such as inserting parts into objects placed on the pallets. Concerning a conveying device that automatically and continuously carries out the process, more specifically, in such a conveying device, the pallet is This invention relates to an improvement in a lifting device for lifting and lowering.

In recent years, mass production technologies have shifted from those that adopted the conventional so-called belt conveyor system to those that aim to significantly automate assembly and stabilize quality by combining automatic work equipment such as robots with conveyance equipment. It's coming.

One of the most widely used devices is one in which objects to be worked are placed on a plurality of pallets, the pallets are conveyed, and the conveyance is stopped during the work. In this case, while the pallet is being circulated, when it comes to the upper side, it becomes the main transport process and is sent to the work area while loading the object, and when the main transport is finished, the object is released (the work on the object is completed at this time),
The pallet is moved to a reverse conveyance process in which the pallet is lowered and returned to its original position. Therefore, each of the plurality of pallets circulates through four strokes: main conveyance stroke, descending stroke, reverse conveyance stroke, and upward stroke, and in the main conveyance stroke, objects to be worked on are loaded, conveyed, and stopped repeatedly. ing.

By the way, in such a conveying device, it is clear that the faster the pallets are circulated in each conveyance stroke, the higher the productivity will be.

However, in a conventional conveying device, the main body of the conveyor was a single endless conveyor chain, with the upper side serving as the main conveying process and the lower side serving as the reverse conveying process, in which pallets were placed on the conveyor chain. However, the speed of the pallets moving in the main conveyance stroke and the reverse conveyance stroke is the same, which has the disadvantage that the number of pallets in the reverse conveyance stroke that does not contribute to production increases, increasing the cost of the entire apparatus.

In order to solve this problem, a proposal has been made to configure two conveyor chains, one for main conveyance and one for reverse conveyance, independently, and to increase the speed of the conveyor chain for reverse conveyance to speed up pallet circulation.

FIG. 1 shows a structural diagram of an example of such a conveying device.

In the figure, a main conveyor chain 1 and a reverse conveyor chain 2 are each independently driven in the directions indicated by arrows. Therefore, the pallet 3 is conveyed to the left on the conveyor chain 1 and to the right on the conveyor chain 2.

Further, lifters 4 and 4' for pallets 3 are provided at both ends of the conveyor chains 1 and 2.

Since it is configured in this way, palette 3 is
It is circulated through four strokes: a main conveyance stroke by the conveyor chain 1, a downward stroke by the lifter 4, a reverse conveyance stroke by the conveyor chain 2, and an upward stroke by the lifter 4'. In this case, if the speed of the conveyor chain 2 is increased, the number of pallets in the reverse conveyance process that does not contribute to production can be reduced, and costs can be reduced accordingly.

In this way, by making the main conveyance section and the reverse conveyance section independent, and by increasing the pallet conveyance speed in the reverse conveyance section, there is an advantage that the number of pallets can be reduced. However, as is clear from the figure, the lifting and lowering transfer cycle stroke of the lifters 4, 4' places the pallet 3 on the lifters 4, 4'. Lower (raise) lifters 4 and 4'. The pallet 3 is placed on the conveyors 2, 1 from the lifters 4, 4'. Raise (lower) lifters 4, 4' to their original positions. Because it consists of four strokes, the cycle time required for this lifting stroke may be longer than the cycle time required for other transport strokes, and as a result, the cycle time of the entire conveyance device is dominated by the cycle time for this lifting stroke. I had the inconvenience of being rejected. In other words, this means that even if the work cycle time in the main transport stroke or the reverse transport cycle time in the reverse transport stroke is shortened, the speed of the transport device cannot be made faster than the cycle time in the lifting stroke.

Therefore, an object of the present invention is to shorten the cycle time of such a lifting device, thereby increasing the speed of the entire conveying device.

FIG. 2 is a diagram showing the stroke of an elevating device as an example of the conveying device according to the present invention.

In the figure, the same parts as in FIG. 1 are denoted by the same reference numerals, and explanations of those parts will be omitted.

The configuration differs from FIG. 1 in that a conveyor chain 5 of the auxiliary conveyance section is provided close to the end of the conveyor chain 1 of the main conveyance section and on the side in the conveyance direction.

First, in the first stroke shown in Figure A, the lifter 4
At the same time, a pallet 3 is placed on the conveyor chain 2 from the conveyor chain 1, and at the same time another pallet 3 is placed on the conveyor chain 5 from the conveyor chain 1. Subsequently, in the second stroke shown in FIG. Next, in the third stroke shown in Figure C, the conveyor chain 5 escapes laterally and the lifter 4 descends. When the conveyor chain 5 finishes descending, the conveyor chain 5 returns to its original position and enters the state shown in FIG.

As described above, in this lifting device, the auxiliary conveyance section is configured separately from the lifter 4, so that the cycle for lifting and lowering the pallet 3 only takes three strokes, and the cycle time in the lifting device can be shortened.

Next, a specific example of the above-mentioned elevating device will be described in detail with reference to FIG. 3 and subsequent figures.

Figure 3 is a detailed structural diagram of the lifting device, Figure 4 A,
B, C, and D are diagrams showing details of the stroke in the lifting device, A, B, and D are front views, and C is a side view.

In FIG. 3, the conveyor chain 1 of the main conveyance section is driven by a motor 6 as a drive source via a deceleration mechanism 7. As shown in FIG. Further, the rotational force of the speed reduction mechanism 7 drives the conveyor chain 12 of the auxiliary conveyance section through the bevel gears 8 to 11, and similarly the bevel gear 13
16 to 16 drive another conveyor chain 17 of the same auxiliary conveyor section.

The lifting mechanism includes a lifter 18, a motor 19, a crank arm 20, and the arm 20 and the lifter 18.
The lifter 18 is made up of a connecting rod 21 that connects the lifters 18 and 18, and the lifter 18 is moved up and down by the rotation of a motor 19. Additionally, a cam 22 is attached to the rotating shaft of the motor 19.
is attached coaxially with the crank arm 20, and a link 23 is supported on the cam 22 by a pin 24, and a connecting rod 25 is rotatably attached to one end of the link 23. The tip of this connecting rod 25 is connected to the conveyor chain 17 and the bevel gear 1.
The connecting rod 25 is attached to an auxiliary conveying unit 26 including the connecting rods 3 to 16, and the unit 26 swings when the connecting rod 25 moves up and down.
Link 2 that similarly operates integrally with link 23 above.
7 is provided, and by vertical movement of the connecting rod 28, the conveyor chain 12 and the bevel gears 8 to 1 are connected.
The auxiliary transport unit 29 including the transport unit 1 is configured to perform a swinging movement. The cam 22 is shaped to swing the auxiliary conveyance unit 29 to such an extent that the pallet can move downward together with the lifter 18 before the lifter 18 moves downward from the top dead center. Further, the cam 22 has a shape that returns the auxiliary transport unit 29 to its original transportable state during one rotation of the cam 22.

Note that 30 is a lifting device unit in which each of the above-mentioned elements is housed. To configure the conveyance device, as shown in Fig. 1, two lifting device units are required.
A stand is required. The motor, deceleration mechanism, etc. for driving the conveyor chain 2 of the reverse conveyance section are housed in another elevator unit (not shown). In that case, the configuration of each element is the third
It is roughly the same as shown in the figure.

Next, referring to FIG. 4, the operation of the elevating device having the above structure will be explained.

First, it is assumed that the upper pallet 3 is conveyed from the conveyor chain 1 to the conveyor chains 12 and 17 of the auxiliary conveyance section, and reaches a position where it can be lowered (see A in the same figure). At this time, another pallet 3' is discharged from the lifter 18 of the lifting mechanism to the conveyor chain 2, and the lifter 18 becomes empty. When a pallet detection device (not shown) detects that the lower pallet 3' has been discharged, the lifter 18 begins to rise (see b). and crank arm 2
0 reaches the top dead center, that is, when the lifter 18 reaches the rising end, the auxiliary conveyance units 26 and 29 that had supported the pallet 3 up to that time swing from side to side, and the pallet 3 moves above the lifter 18. The vehicle can be lowered by resting on it (see C in the same figure). In this case, the mounting position of the cam 22 is set appropriately, and the links 23 and 27 act immediately after the crank arm 20 passes the top dead center, so that the unit 2
Since the units 6 and 29 are designed to swing, the pallet 3 can be lowered without the units 26 and 29 and the lifter 18 interfering with each other. Thereafter, the lifter 18 begins to descend (see D in the figure), and when the crank arm 20 reaches the bottom dead center, that is, when the lifter 18 reaches the lowering end, the operation of the lifting mechanism stops. Note that the motor 19 has a one-rotation stop mechanism.

Next, when the lifter 18 reaches the lower end, the pallet 3 placed on it is discharged onto the lower conveyor chain 2 and returns to the first stroke shown in FIG. In addition, just before the crank arm 20 reaches the bottom dead center, the auxiliary transport units 26 and 2
9 swings back to its original state, allowing the process of A in the figure to be carried out again.

Repeating the above process, pallet 3 is transferred from upper conveyor chain 1 to lower conveyor chain 2.
will be sequentially transferred to

The lifting device unit 30 takes the step of lowering the pallet 3 as described above, but the other lifting device unit (not shown) takes the step of raising the pallet 3. However, it will be understood that even in this case, the operation of the lifting mechanism is the same as that shown in FIG. That is, the pallet lifting and lowering transfer cycle steps in these units include a pallet delivery process (see Figure 4A), a lifter's ascending process (see Figure 4B), a lifter's descending process (see Figure 4D), It only takes 3 steps.

As described above, according to the present invention, the cycle of lifting and lowering the pallets in the lifting device can be made into three steps, so the cycle time of the conveying device can be further shortened, and as a result, the circulation of pallets can be speeded up. There is. In addition, since a single motor is used to move the lifter up and down and swing the auxiliary transport section, the structure is simple, and the advantage is that the up and down movement of the lifter and the swinging motion of the auxiliary transport section can be easily synchronized. There is.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing an example of a conventional conveying device.
Fig. 2 is a diagram showing the stroke of an elevating device as an example of the conveying device according to the present invention, Fig. 3 is a detailed structural diagram embodying the elevating device, Fig. 4 is a, b,
C and D are diagrams showing details of the stroke in the above-mentioned elevating device. 1, 2... Conveyor chain, 3... Pallet, 4, 18... Lifter, 5, 12, 17...
Conveyor chain, 20...Crank arm, 2
1, 25, 28...Connecting rod, 22...Cam, 23
... Link, 26, 29 ... Auxiliary transport unit,
30... Lifting device unit.

Claims (1)

[Scope of Claims] 1. A conveyance device comprising at least a main conveyance section and a reverse conveyance section for pallets, each having a different conveyance speed, and an elevating device for moving the pallet up and down between these two conveyance sections, The device includes: an auxiliary transport section that is provided in the main transport direction close to the main transport section and is swingably supported; and a lifter that is supported vertically and movably between the auxiliary transport section and the reverse transport section. , a motor, a crank arm connected to the rotating shaft of the motor, a first connecting rod connecting the crank arm and the lifter, a cam connected to the rotating shaft of the motor, and an operation of the cam. The cam includes a driven member that is driven and a second connecting rod that connects the driven member and the auxiliary member, and the cam is configured to move the pallet downward together with the lifter before the lifter moves downward from the top dead center. A conveyance device, characterized in that it has a shape that allows the auxiliary member to swing to such an extent that it can be moved, and a shape that returns the auxiliary member to its original transportable state during one rotation.