JP2001171832A - Work transferring method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a work from a floor conveyor to an overhead conveyor in a short time. SOLUTION: This device has a first lifter L1 for vertically moving a work W between a lower work transfer position P1 and an intermediate work transfer position P3 of a floor conveyor C1, and a second lifter L2 for vertically moving the work W between an upper work transfer position P2 and the intermediate work transfer position P3 of an overhead conveyor 2. The second lifter L2 is lowered from the upper work transfer position P2 to the intermediate work transfer position P3 during a time when the work W is raised from the lower work transfer position P2 to the intermediate work transfer position P3 by the first lifter L1. The first lifter L1 is lowered from the intermediate work transfer position P3 to the lower work transfer position P1 during a time when the second lifter L2 is raised from the intermediate work transfer position P3 to the upper work transfer position P2 after the work W is transferred from the first lifter L1 to the second lifter L2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work transfer method for transferring a work from a floor conveyor to an overhead conveyor, and a work transfer apparatus used directly for carrying out the method.

[0002]

2. Description of the Related Art In order to transfer a work from a floor conveyer to an overhead conveyer, a pair of elevating members which move up and down in synchronism along two columns are provided. What transports in the direction is known.

A pair of motors for raising and lowering a pair of elevating members that move up and down along two columns are linked by an interlocking shaft so that both elevating members are moved up and down synchronously. What is disclosed in JP-A-5-16
No. 2989.

[0004]

When a work is transferred from a floor conveyor to an overhead conveyor using a single lifter, the lifting member of the lifter that has received the work from the floor conveyor moves to a position of the overhead conveyor. After ascending and discharging the work, the empty elevating member descends again to the floor conveyor position and
The cycle will be completed. Therefore, in order to shorten the time of one cycle, it is necessary to increase the elevating speed of the elevating member, and therefore, there is a problem that the driving source for driving the elevating member becomes large.

When the pair of right and left elevating members is raised and lowered in synchronization with each other, if the interlocking shaft described in the above-mentioned Japanese Patent Application Laid-Open No. 5-1621989 is employed, the work supported by the left and right elevating members and the interlocking shaft may interfere with each other. In such a case, it is necessary to adopt another synchronization means. As another synchronizing means, it is conceivable to control the left and right elevating members by a servomotor. However, adopting a servomotor has a problem that the cost is greatly increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a work transfer method capable of saving a work time for transferring a work from a floor conveyor to an overhead conveyor. Another object of the present invention is to synchronize a pair of motors for driving the left and right lifting members of the lifter without using an interlocking shaft or a servomotor in the work transfer device used in the work transfer method.

[0007]

According to the first aspect of the present invention, a lower work transfer position provided on a floor conveyor is provided between a floor conveyor and an overhead conveyor. A first lifter that raises and lowers the work between the intermediate work transfer position; and a second lifter that raises and lowers the work between the upper work transfer position provided on the overhead conveyor and the intermediate work transfer position.
A work transfer method for transferring a work from a floor conveyor to an overhead conveyor using a lifter;
One step of transferring the work from the floor conveyor to the first lifter at the lower work transfer position, and separating the first lifter supporting the work and the empty second lifter from the lower work transfer position and the upper work transfer position, respectively; A second step of substantially simultaneously moving the work to the work transfer position, a third step of transferring the work from the first lifter to the second lifter at the intermediate work transfer position, and a second step of supporting the empty first lifter and the work. A fourth step of moving the lifter from the intermediate work transfer position to the lower work transfer position and the upper work transfer position substantially simultaneously, and a fifth step of discharging the work from the second lifter to the overhead conveyor at the upper work transfer position.
A work transfer method characterized by performing the above steps is proposed.

[0008] According to the above configuration, the first supporting the work.
The lifter and the empty second lifter are moved from the lower work transfer position and the upper work transfer position to the intermediate work transfer position almost simultaneously, respectively, and the first lifter and the empty second lifter are moved to the first position at the intermediate work transfer position.
After transferring the work from the lifter to the second lifter, the empty first lifter and the second lifter supporting the work are moved from the intermediate work transfer position to the lower work transfer position and the upper work transfer position, respectively, substantially simultaneously. Therefore, the time for the first lifter to reciprocate the distance between the lower work transfer position and the intermediate work transfer position, or the time for the second lifter to reciprocate the distance between the upper work transfer position and the intermediate work transfer position is one. This is a cycle time, and the time required for the transfer operation can be reduced as compared with the case where one cycle is completed by reciprocating a single lifter between the lower work transfer position and the upper work transfer position.

According to the invention described in claim 2,
2. The work transfer device used in the work transfer method according to claim 1, wherein the first lifter is provided on a pair of columns erected with a floor conveyor interposed therebetween, and the first lifter is provided on both columns so as to be able to move up and down. , A pair of motors for independently raising and lowering the two lifting members, a pair of pulse encoders for detecting the rotational speeds of both motors, and control means for controlling the driving of both motors. The control means continues driving both motors when the count values of the outputs of both pulse encoders after the first lifter starts rising from the lower work transfer position are coincident with each other; Wherein the count value is reset when the first and second lifters return to the lower workpiece transfer position when the first and second lifters return to the lower workpiece transfer position. There is proposed.

According to the above construction, the count values of the outputs of the two pulse encoders after the first lifter starts rising from the lower work transfer position are compared, and when the count values become inconsistent, the two motors are compared. Is forcibly stopped, so that it is possible to prevent the occurrence of a difference between the rotational speeds of the left and right motors and the inclination of the left and right elevating members. Moreover, when the first lifter returns to the lower work transfer position without forcibly stopping the drive of both motors, the count values of the outputs of both pulse encoders are reset, so that the count values accumulate and the motor becomes unnecessary. The stoppage can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 10 show an embodiment of the present invention. FIG. 1 is a front view of a work transfer device, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 4 is an enlarged view of a main part of FIG. 2, FIG. 5 is an enlarged view of a main part of FIG. 3, and FIG.
7 is an operation explanatory view corresponding to FIG. 4, FIG. 8 is an operation explanatory view corresponding to FIG. 5, FIG. 9 is a block diagram of a control system of a motor of the first lifter, and FIG. It is a flowchart explaining control of the motor of a lifter.

As shown in FIG. 1, a work transfer apparatus for transferring an automobile body W as a work carried in at a predetermined time interval on a floor conveyor C1 to an overhead conveyor C2 uses a floor transfer work at a lower work transfer position P1. Conveyor C1
Lifter L1 that raises the vehicle body W received from the intermediate work transfer position P3, and raises the vehicle body W received from the first lifter L1 at the intermediate work transfer position P3 and moves the overhead conveyor at the upper work transfer position P2. A second lifter L2 to be transferred to C2.

The floor conveyor C1 has a carriage 11 which supports the vehicle body W and travels in the direction of arrow a.
1 can be stopped at the lower workpiece transfer position P1. The overhead conveyor C2 is provided with a hanger 13 which runs in the direction of arrow b along the guide rail 12, and the lifting rail 14 which constitutes a part of the guide rail 12 at the upper work transfer position P2 is provided together with one hanger 13. It can be moved up and down.

Next, the structure of the first lifter L1 is shown in FIGS.
It will be described based on.

The first lifter L1 is a pair of right and left columns 21L, 21R erected on both sides in the conveying direction of the floor conveyor C1.
Is provided. Two guide rails 22 are fixed to both sides of each of the columns 21L and 21R.
A total of eight guide rollers 2 provided on the base end side of L, 23R
4 is rolled along the two guide rails 22, so that the elevating members 23L, 23R are supported by the columns 21L, 21R.
It can move up and down along R. Left and right work support portions 25L, 25R that support the lower surface of the side sill portion of the vehicle body W are provided on the distal ends of the lifting members 23L, 23R. Prop 2
Motors 27L and 27R are provided on the upper surface of a substrate 26 fixed to the upper ends of 1L and 21R, respectively.
The drive sprockets 29L and 29R are provided. A pulse encoder 30L, which outputs a pulse according to the rotation angle of the motor 27L, 27R, is provided at the tip of each drive shaft 28.
30R are provided.

The rotation of the motors 27L and 27R is transmitted to the drive shaft 28 at a reduced speed.
Is not the same as the rotation speed detected by the pulse encoders 30L and 30R,
By correcting the rotational speed detected by R based on the reduction ratio, the rotational speeds of the motors 27L and 27R can be known.

One end of the two chains 31 wound around the two drive sprockets 29L and 29R is connected to the lifting member 2
3L and 23R, and the other end is connected to a counterweight 32 housed in the columns 21L and 21R so as to be able to move up and down. Therefore, by driving the left motor 27L, the left lifting member 23L can be raised and lowered via the driving sprocket 29L and the chain 31,
At this time, the load on the motor 27L can be reduced by the action of the counterweight 32. Similarly, the right motor 2
By driving the 7R, the right lifting member 23R can be raised and lowered via the driving sprocket 29R and the chain 31, and at this time, the load on the motor 27R can be reduced by the action of the counterweight 32.

An upper limit switch 33 and a lower limit switch 34 are provided on the upper and lower portions of the columns 21L and 21R, respectively.
By operating the upper limit switch 33 and the lower limit switch 34 by the dogs 46 and 47 provided in the above, the upper limit position and the lower limit position of the lifting members 23L and 23R are detected.

A stay 36 provided on the left elevating member 23L is provided.
Are provided with four light transmitters 37, and the right elevating member 23R
Are provided with four light receivers 39.
The four light transmitters 37 are opposed to the four light receivers 39, respectively, and the light emitted from the predetermined light transmitter 37 is blocked by the vehicle body W, so that the plurality of types of the vehicle The front-back position is detected.

The work supporting portions 25L, 25R are provided on a forward / backward moving table 41 movable by a drive source (not shown) along two rails 40 provided on the elevating members 23L, 23R. A left and right moving table 44 movable by a cylinder 43 along two rails 42 is provided. A pair of front and rear vehicle body supporting portions 45 provided on the left and right moving table 44 can support a lower surface of a side sill of the vehicle body W. is there.

Next, the structure of the second lifter L2 is shown in FIGS.
It will be described based on.

The second lifter L2 is provided with a pair of front and rear columns 51f and 51r erected on the right side of the floor conveyor C1, and two guide rails 52 are provided on the side surfaces of the columns 51f and 51r. Front and rear elevating members 53f, 5
Eight guide rollers 54 provided on the base end side of 3r
Are rolled along the two guide rails 52, so that the elevating members 53f, 53r are supported by the columns 51L, 51R.
It can be moved up and down along.

A pair of front and rear motors 56f, 56r are provided on the upper surface of the board 55 connecting the upper ends of the front and rear columns 51f, 51r.
The output shafts of both motors 56f and 56r are integrally connected by an interlocking shaft 57 and rotate synchronously. A pair of driving sprockets 58f, 58r are provided at both ends of the interlocking shaft 57.
Are provided, and these drive sprockets 58f,
A pair of idle sprockets 59 is provided corresponding to 58r. One end of a chain 60 wound around one driving sprocket 58f and one idle sprocket 59 is connected to a front elevating member 53f, and the other end is
Counter weight 6 housed inside 1f so as to be able to move up and down
1 and the other drive sprocket 58
One end of the chain 60 wound around r and the other idle sprocket 59 is connected to a rear elevating member 53r, and the other end is connected to a counterweight 61 housed inside the column 51r so as to be able to move up and down.

Therefore, by driving the front and rear motors 56f and 56r, the front and rear drive sprockets 58f and 58r are rotated synchronously by the action of the interlocking shaft 57, and the front and rear lifting members 53f and 53r are moved via the chain 60. Can be moved up and down synchronously. At that time, counter weight 6
The effect of 1 can reduce the load on the motors 56f and 56r.

On the lower surface of the connecting member 62 for connecting the front and rear elevating members 53f and 53r, the elevating rail 14 constituting a part of the guide rail 12 of the overhead conveyor C2 is provided.
Is fixed. The hanger 13 of the overhead conveyor C2 has a front drive wheel 63 that engages with the lift rail 14.
And a driven wheel 64 on the rear side, and can be driven by driving a driving wheel 63 with a motor 65. The hanger 13 has four suspension arms 66 that can be opened and closed by a drive source (not shown) to support the upper edge of the door opening of the vehicle body W.

Next, the operation of the work transfer device having the above configuration will be described.

In the initial state of starting one cycle of transferring the vehicle body W from the floor conveyor C1 to the overhead conveyor C2, the left and right lifting members 23 of the first lifter L1
L, 23R are waiting at the lower workpiece transfer position P1,
The lifting members 53f and 53r before and after the second lifter L2 are waiting at the upper workpiece transfer position P2.

As shown in FIGS. 7 and 8, the truck 11 of the floor conveyor C1 on which the vehicle body W is mounted moves forward and enters the lower work transfer position P1, and the light transmitter 3 of the first lifter L1 is moved.
When a predetermined number of optical axes of the four optical axes connecting the light receiving device 7 and the light receiver 39 are cut off, the floor conveyor C1 stops.
Thereby, the vehicle body W on the trolley 11 is positioned at a correct position determined according to the model, and the positional relationship between the vehicle body W and the first lifter L1 is secured. Subsequently, the cylinders 43 of the left and right elevating members 23L and 23R extend, and the left and right moving tables 44 move in a direction approaching each other, and the vehicle body support portions 45 enter the lower surface of the side sill portion of the vehicle body W.
At this time, the front and rear positions of the left and right lifting members 23L and 23R of the front and rear moving table 41 are adjusted in advance according to the model of the vehicle body W.

Subsequently, when the left and right elevating members 23L, 23R are raised by synchronizing the left and right elevating members 23L, 23R with the chain 31 by driving the left and right motors 27L, 27R,
The vehicle body W whose side sill portion is locked to the vehicle body supporting portion 45 of the vehicle is scooped up from the cart 11 of the floor conveyor C1 and rises. When the left and right elevating members 23L and 23R reach the intermediate work transfer position P3 and the dog 46 operates the upper limit switch 33, the left and right motors 27L and 27R stop and the elevating members 23L and 23R move the intermediate work transfer. It stops at the position P3. In this manner, while the lifting members 23L and 23R of the first lifter L1 are rising from the lower work transfer position P1 toward the intermediate work transfer position P3, the second lifter 23L and 23R are moved upward.
The motors 56f, 56r of the lifter L2 are driven to lower the lifting members 53f, 53r supporting the empty hanger 13 from the upper work transfer position P2 to the intermediate work transfer position P3. At this time, the suspension arm 66 of the hanger 13 is open left and right.

As shown in FIG. 1, the lower workpiece transfer position P
Since the distance H1 between the first work transfer position P3 and the intermediate work transfer position P3 is smaller than the distance H2 between the upper work transfer position P2 and the intermediate work transfer position P3, the distance H1 is supported by the lifting members 23L and 23R of the first lifter L1. The vehicle body W first arrives at the intermediate work transfer position P3 and stands by, and the empty hanger 13 supported by the second lifter L2 arrives there with a slight delay. When the empty hanger 13 supported by the second lifter L2 reaches the intermediate work transfer position P3, its suspension arm 66
Is closed, the upper edge of the door opening of the vehicle body W is locked.

The motors 56f, 5 of the second lifter L2
6r is rotated in the reverse direction to scoop up the vehicle body W supported by the hanger 13 from the lifting members 23L and 23R of the first lifter L1 and raise it toward the upper workpiece transfer position P2, and at the same time, the motor 27L of the first lifter L1 , 27R are rotated in reverse, and the empty lifting members 23L, 23R are lowered toward the first work transfer position P1. Lifting member 5 of second lifter L2
When 3f and 53r reach the upper workpiece transfer position P2, the hanger 13 is self-propelled and paid out from the elevating rails 14 of the elevating members 53f and 53r to the guide rails 12 of the overhead conveyor C2. 13 is entered. Further, the elevating members 23L, 23R of the first lifter L1 lowered to the first work transfer position P1.
Stops at the position where the dog 47 operates the lower limit switch 34.

As described above, while the lifting members 23L and 23R of the first lifter L1 supporting the vehicle body W rise from the lower work transfer position P1 to the intermediate work transfer position P3, the empty second lifter L2 The elevating members 53f, 53r are lowered from the upper work transfer position P2 to the intermediate work transfer position P3, and the elevating members 23L, 23R of the empty first lifter L1 are moved from the intermediate work transfer position P3 to the lower work transfer position P1. When the lifter 53f, 53r of the second lifter L2 supporting the vehicle body W rises from the intermediate work transfer position P3 to the upper work transfer position P2 during the downward movement, the moving speed of the lifter is assumed to be constant. In addition, the time required for the transfer operation can be reduced as compared with the case where a single lifter is reciprocated up and down between the lower work transfer position P1 and the upper work transfer position P2.

This is because, when a single lifter is used, it takes one cycle for the lifter to reciprocate the distance H1 + H2 (see FIG. 1) between the lower work transfer position P1 and the upper work transfer position P2. According to the present embodiment, the time required for the first lifter L1 to reciprocate the distance H1 between the lower work transfer position P1 and the intermediate work transfer position P3,
Alternatively, the time required for the second lifter L2 to reciprocate the distance H2 between the upper work transfer position P2 and the intermediate work transfer position P3 is one cycle time. Actually, since the distance H2 is larger than the distance H1, the time for the second lifter L2 to reciprocate the distance H2 between the upper work transfer position P2 and the intermediate work transfer position P3 is one cycle time of the present embodiment. However, during that time, a single lifter is located at a distance of H1 + H
Obviously, it takes less time than it takes to make a round trip.

Next, the control of the left and right motors 27L, 27L of the first lifter L1 will be described with reference to FIGS.

The motors 56f, 5 before and after the second lifter L2
Since 6r is connected by the interlocking shaft 57 and forcibly rotates, the front and rear elevating members 53f and 53r can move up and down synchronously without shifting vertically. On the other hand, since the left and right motors 27L and 27R of the first lifter L1 are not connected by the interlocking shaft 57, the left and right motors 27L and 27R are output based on the outputs of the left and right pulse encoders 30L and 30R.
L and 27R are rotated synchronously, and the left and right elevating members 23L and 2L are rotated.
The 3R is prevented from shifting vertically. First lifter L1
The reason that the left and right motors 27L and 27R are not synchronized by the interlocking axis is that the vehicle body W is located in the space between the left and right motors 27L and 27R.
When the interlocking shaft is provided, the vehicle body W
It is because it interferes.

As shown in FIG. 9, an electronic control unit U including a microcomputer includes left and right inverters 71L,
The speed command and the drive command are output to 71R, and the left and right motors 27L and 27R operate according to the commands. The pulses output from the left and right pulse encoders 30L and 30R in response to the rotation of the left and right motors 27L and 27R are counted by the left and right counters 72L and 72R, and the result is input to the electronic control unit U. Counter 72L, 7
The count value of 2R is reset to “0” by a command from the electronic control unit U when the left and right elevating members 23L and 23R of the first lifter L1 are at the lower limit position. When the count values of the left and right counters 72L and 72R do not match, the electronic control unit U operates the left and right motors 27L and 72R.
A stop command for stopping the driving of the L and 27R is issued to the inverter 71.
L, 71R.

Next, the above operation will be further described with reference to the flowchart of FIG.

First, at step S1, when the first lifter L1 is at the lower limit position, at step S2, the motor 27L,
The first lifter L1 is operated by driving 27R, and in step S3, the pulses output by the pulse encoders 30L and 30R are counted according to the rotation of the motors 27L and 27R. In step S4, before the first lifter L1 returns from the lower limit position to the lower limit position via the central workpiece transfer position P3, in step S5, the output of the left counter 72L that counts the rotation speed of the left motor 27L. And a right counter 72 for counting the number of rotations of the right motor 27R.
If the deviation between the outputs of the counters 72L and 72R is equal to or less than a preset threshold value, it is determined that the left and right lifting members 23L and 23R are moving up and down in synchronization, and the process returns to step S2. Thus, the driving of both motors 27L and 27R is continued as it is.

On the other hand, in step S5, both counters 7
If the deviation between the outputs of the 2L and 72R exceeds the threshold value, it is determined that the left and right elevating members 23L and 23R may be out of synchronization and the vehicle body W may be tilted, and the driving of both motors 27L and 27R is forcibly stopped. . If the first lifter L1 returns from the lower work transfer position P1 to the lower limit position via the central work transfer position P3 in step S4 without forcibly stopping the driving of both motors 27L and 27R, step S7. To stop both motors 27L and 27R, and reset the count values of left and right counters 72L and 72R to "0" in step S8. Thereby, the difference between the rotation speeds of the left and right motors 27L and 27R is determined by
L, 72R to prevent accumulation by both motors 27L,
27R can be prevented from stopping unnecessarily.

As described above, the left and right motors 27L, 27L
The number of rotations of R is detected and compared by the pulse encoders 30L and 30R, and when the deviation exceeds a threshold value, the motor 27L,
Since 27R is stopped, the left and right motors 27L, 27R
Of the vehicle body W supported by the first lifter L1 can be reliably prevented without connecting them with an interlocking shaft and without using an expensive servomotor.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the deviation between the outputs of the counters 72L and 72R exceeds the threshold value before the first lifter L1 departs from the lower work transfer position P1 and returns to the lower work transfer position P1 again. In this case, the motors 27L and 27R are stopped, but this can be changed before the first lifter L1 starts from the lower work transfer position P1 and reaches the intermediate work transfer position P3. Because the first
The period during which the lifter L1 departs from the intermediate work transfer position P3 and returns to the lower work transfer position P1 is after the vehicle body W has been delivered to the second lifter L2.
This is because a slight out-of-sync of R does not matter.

A period during which the first lifter L1 rises from the lower work transfer position P1 to the intermediate work transfer position P3, and a period during which the second lifter L2 descends from the upper work transfer position P2 to the intermediate work transfer position P3. Does not need to completely overlap with each other, as long as some of the periods overlap. Similarly, a period during which the first lifter L1 descends from the intermediate work transfer position P3 to the lower work transfer position P1, and a period during which the second lifter L2 rises from the intermediate work transfer position P3 to the upper work transfer position P2. It is not necessary that they completely overlap, and it is only necessary that some of the periods overlap.

In the embodiment, the body of the automobile is exemplified as the work, but the present invention can be applied to any other work.

[0046]

As described above, according to the first aspect of the present invention, the first lifter supporting the work and the empty second lifter are provided.
Move the lifters from the lower work transfer position and the upper work transfer position to the intermediate work transfer position almost simultaneously,
After the work is transferred from the first lifter to the second lifter at the intermediate work transfer position, the empty first lifter and the second lifter supporting the work are moved from the intermediate work transfer position to the lower work transfer position and the upper work, respectively. Since the first and second lifters are moved to the transfer position almost simultaneously, the first lifter reciprocates the distance between the lower work transfer position and the intermediate work transfer position, or the second lifter moves between the upper work transfer position and the intermediate work transfer position. The time required for the reciprocating operation is one cycle, and the transfer work is required as compared with the case where a single lifter is reciprocated between the lower work transfer position and the upper work transfer position to complete one cycle. Time can be reduced.

According to the second aspect of the present invention,
Compare the count values of the outputs of both pulse encoders after the first lifter starts rising from the lower work transfer position,
Since the driving of both motors is forcibly stopped when the count values become inconsistent, it is possible to prevent the occurrence of a difference between the rotational speeds of the left and right motors and the inclination of the left and right elevating members beforehand. . Moreover, when the first lifter returns to the lower work transfer position without forcibly stopping the driving of both motors,
Since the count values of the outputs of both pulse encoders are reset, it is possible to prevent the count values from accumulating and stopping the motor unnecessarily.

[Brief description of the drawings]

FIG. 1 is a front view of a work transfer device.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a view in the direction of arrows in FIG. 2;

FIG. 4 is an enlarged view of a main part of FIG. 2;

FIG. 5 is an enlarged view of a main part of FIG. 3;

FIG. 6 is a view taken along line 6-6 of FIG. 4;

FIG. 7 is an operation explanatory view corresponding to FIG. 4;

FIG. 8 is an operation explanatory view corresponding to FIG. 5;

FIG. 9 is a block diagram of a control system of a motor of the first lifter.

FIG. 10 is a flowchart illustrating control of a motor of a first lifter.

[Explanation of symbols]

 C1 Floor conveyor C2 Overhead conveyor L1 First lifter L2 Second lifter P1 Lower work transfer position P2 Upper work transfer position P3 Intermediate work transfer position U Electronic control unit (control means) W Body (work) 21L Support 21R Support 23L Lifting member 23R Lifting member 27L Motor 27R Motor 30L Pulse encoder 30R Pulse encoder

Claims (2)

[Claims] 1. Between a lower work transfer position (P1) provided on a floor conveyor (C1) and an intermediate work transfer position (P3) provided between a floor conveyor (C1) and an overhead conveyor (C2). Lifter (L1) for raising and lowering the work (W) by means of an overhead conveyor (C)
2) using a second conveyor (L2) for raising and lowering the work (W) between the upper work transfer position (P2) provided above and the intermediate work transfer position (P3); A work transfer method for transferring a work (W) from C1) to an overhead conveyor (C2), comprising a first lifter (L) at a lower work transfer position (P1).
1) a process of transferring the work (W) from the floor conveyor (C1) to the floor conveyor (C1), and a first work lifter (L1) supporting the work (W) and an empty second lifter (L2) are each transferred to a lower work. (P
1) and a second step of substantially simultaneously moving the upper work transfer position (P2) to the intermediate work transfer position (P3); and a first lifter (L) at the intermediate work transfer position (P3).
The third step of transferring the work (W) from 1) to the second lifter (L2), and the transfer of the intermediate work to the empty first lifter (L1) and the second lifter (L2) supporting the work (W). A fourth step of moving from the position (P3) to the lower work transfer position (P1) and the upper work transfer position (P2) substantially simultaneously, respectively, and a second lifter (L) at the upper work transfer position (P2).
A fifth step of discharging the work (W) from 2) to the overhead conveyor (C2). 2. The work transfer device used in the work transfer method according to claim 1, wherein the first lifter (L1) is a pair of pillars (11) standing upright with a floor conveyor (C1) interposed therebetween. 21L, 21R) and a pair of elevating members (23L, 21L, 21L, 21R) which are provided on both columns (21L, 21R) so as to be able to move up and down and support the work (W) from both sides.
23R), a pair of motors (27L, 27R) for independently raising and lowering the two lifting members (23L, 23R), and a pair of pulse encoders (30L, 30R) for detecting the rotation speeds of both motors (27L, 27R). 30R) and control means (U) for controlling the driving of both motors (27L, 27R), wherein the control means (U) raises the first lifter (L1) from the lower work transfer position (P1). When the count values of the outputs of both pulse encoders (30L, 30R) coincide with each other after the start of the operation, the driving of both motors (27L, 27R) is continued. A work wherein the drive of the motors (27L, 27R) is stopped and the count value is reset when the first lifter (L1) returns to the lower work transfer position (P1). Transfer equipment.