JP2808989B2 - Positioning method of body parts by carrier cart - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of assembling a vehicle body on an automobile body assembly line, using a vehicle body component carrier as a part of a vehicle body assembly jig not only as a transport means but also as a part of a vehicle body assembly jig. The present invention relates to a method for positioning a body part by a carrier vehicle, which performs predetermined processing or work while being positioned on the carrier vehicle.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 2-286478 discloses a method for positioning a vehicle body part by using a carrier of this type. In this conventional method, a body part is positioned on the basis of the work receiving member with respect to a self-propelled carrier having a work receiving member whose position in three orthogonal directions can be adjusted, and the carrier is moved to a predetermined position. After traveling along the closed loop-shaped transport trajectory, in the vehicle body assembling process provided on the above-described transport trajectory, after performing the stop position accuracy of the transport trolley with the reference member on the vehicle body assembling process side,
An operation such as spot welding by a robot is performed on a body part positioned with reference to the work receiving member.

A jig switching step is provided on the transfer track separately from the vehicle body assembling step, and a drive unit capable of engaging and disengaging a part of the transfer carriage is provided in the jig switching step. The three-dimensional position of the work receiving member is switched and changed by a drive unit according to the type of a vehicle body component to be positioned on the carrier.

On the other hand, a so-called electric train, which is driven by an electric motor as a drive source while receiving power supplied from a power supply line provided on the side of the transfer rail, is used as a transfer vehicle used for transferring or positioning the body parts as described above. 2. Description of the Related Art Transport vehicles of the type are known.

[0005] In this train-type transport trolley, wear of the transport rails or wheels due to long-term use may directly affect the press-contact state between the power supply line and the current collecting brush, and may cause poor energization. 1-12-1
As shown in Japanese Patent Application No. 487 (Japanese Utility Model Application No. 63-29332), the displacement of the transport vehicle caused by wear of the sliding surface between the transport rail and the transport vehicle is detected during the travel of the transport vehicle. A sensor is provided to monitor the degree of the displacement.

[0006]

However, in the case of the latter (Japanese Utility Model Laid-Open No. 1-132487),
It merely detects the displacement of the carriage due to the wear of the running sliding surface and does not have a function of correcting the displacement by the feedback. When applied to positioning, there is no measure against the decrease in positioning accuracy of vehicle body parts caused by the displacement of the carrier.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to prevent the wear of wheels of a transport vehicle from affecting the positioning accuracy of body parts by work positioning means on the transport vehicle. It is intended to provide a method for positioning a vehicle body part by the method described above.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a vehicle body having a work positioning means capable of adjusting a position in a vertical direction is positioned with respect to a vehicle body based on the work positioning means. While traveling along the track, in the vehicle body assembling step on the transport track, predetermined processing or work is performed on the body part positioned with reference to the work positioning means, while in the switching step on the transport track, the switching step is performed. In a method of positioning a body part by a transport vehicle, wherein a vertical position of the work positioning means is changed by a drive unit provided in the vehicle, a measuring step of measuring a wear amount of wheels of the transport vehicle on the transport track is provided. At the same time, the transporting vehicle is provided with storage means, and the wear amount data obtained by the measurement in the measuring step is provided. Is newly written in the storage means each time, and in the switching step, the wear amount data stored in the storage means of the carriage is read out each time and the position of the work positioning means is corrected based on the wear amount data. It is characterized by:

[0009]

According to this method, the wear amount data of the carrier itself measured in the measuring step is stored in the storage means of the carrier and is always attached to the carrier. Therefore, in the switching step, if the wear amount data stored in the storage means is read out and given to the drive unit as position correction data, the drive unit moves the work positioning means by an amount corresponding to the wear amount data and moves the work positioning means. Correct the position. As described above, the influence on the work positioning accuracy due to the wear of the wheels of the transport trolley can be avoided.

[0010]

FIG. 1 is a view showing an embodiment of the present invention, in which a vehicle body assembly line (sub line) 1 includes a rail 2 as a transport track.
Are formed in the form of a closed loop with a plurality of self-propelled carriages 3, 3...
Moves around.

A plurality of assembly stages S1 to S9, a component carry-in stage S11 and a component carry-out stage S12 are provided on the vehicle body assembly line 1. A measuring stage S20 and a positioning device switching stage S30 are provided in front of the component carry-in stage S11. A branch instruction stage S40 is provided downstream of the component unloading stage S12. Further, a bogie maintenance stage S50 is provided at a position branched from a stage subsequent to the branch instruction stage S40. S
Reference numeral 10 denotes an idle stage.

As shown in FIG. 2, each carrier 3 includes a self-propelled drive mechanism 4 for self-propelling and a pair of wheels 5 and 5 at the front stage. A pair of front and rear work positioning devices 7 for positioning and supporting W are mounted.

The work positioning device 7 has a moving mechanism 8 having three orthogonal axes of freedom similar to an orthogonal coordinate type robot.
And a pair of left and right locate pins 9 as work positioning means.
Since the moving mechanism 8 itself does not have a drive source, when the transport carriage 3 is located on the positioning device switching stage S30, the positioning device is mounted on an input shaft (not shown) of the moving mechanism 8. By engaging the drive unit 10 provided on the switching stage S30 and driving it based on the position data corresponding to the type of the vehicle body component W, the locating pin 9 is driven in accordance with the type of the vehicle body component W to be positioned. Can be arbitrarily changed. The details of the moving mechanism 8 and the drive unit 10 are basically the same as those disclosed in JP-A-2-286478.

The movable carriage 3 is provided with a movable communication device 11 for exchanging information with the outside. The communication device 11 has an ID card 12 as storage means and a write / read device for the ID card. And a mechanism for performing the operation.

The carriage 3 receives the vehicle body parts W from a loading robot or a drop lifter (not shown) at the parts loading stage S11 in FIG. ~
S9 is sequentially visited. Each of the assembling stages S1 to S9 has a working machine such as a welding robot and a reference member (not shown) for determining the positional accuracy of the carrier 3. The work such as spot welding is directly performed on the body parts W positioned and supported by the positioning device 7 of the transfer carriage 3 using the transfer carriage 3 as a jig.

The transporting trolley 3 that has made a round of each of the assembly stages S1 to S9 is subjected to its body parts W
Is transferred to a drop lifter or the like, and then travels again toward the component carry-in stage S11 to be circulated and reused. The body parts suspended by the drop lifter at the parts unloading stage S12 are conveyed to another line by another conveyor 13.

The measurement stage S20 includes a transport carriage 3 that is circulated and reused as described above, and a component loading stage S11.
Prior to the entry, the wear amount of each wheel 5 on the side of the transport trolley 3 is set, and the measurement stage S20 includes the wear amount of each wheel 5 as shown in FIG. And a pair of front and rear distance measurement sensors 15 for detecting the distance as a distance from the reference surface 14 on the side of the carriage 3 are provided.
A fixed communication device 16 and a measurement control device 17 are provided.

In the measurement stage S20, the information written in the ID card 12 is read out at any time via the communication devices 11 and 16 according to an instruction from the measurement control device 17, and is taken into the measurement control device 17 side. At the same time, information such as wear amount data measured by the distance measuring sensor 15 can be written at any time via the communication devices 11 and 16 as well. The wireless information communication system centering on the ID card 12 and the communication devices 11 and 16 is basically the same as that disclosed in JP-A-61-108080.

On the other hand, the branch instruction stage S40 in FIG.
As a result of measuring the amount of wear of each wheel 5 as described above, it is determined whether or not the transport vehicle 3 can be reused.
The fixed-side communication device 1 for determining whether maintenance is necessary and instructing the destination of the carrier 3 and communicating with the movable-side communication device 11 on the carrier 3 side.
In addition to 8, a branch control device 19 is provided.

The ID card 12 attached to the carrier 3 is provided for managing data such as the amount of wear of each wheel 5 of the carrier 3 itself. 2, the ID card 12 is detected as a change in the distance between the distance measuring sensor 15 and the reference plane 14 on the side of the transport vehicle 3, as shown in FIG. Number of laps area 12a for managing the number of laps
And an average distance measurement data area 12b for managing the average length measurement value of the past orbits for each wheel 5, and the wear amount itself calculated based on the average distance measurement data and the length measurement value for each wheel 5. And an abrasion amount data area 12c to be managed.

On the other hand, each time the transport vehicle 3 makes one round of the vehicle body assembly line 1, it always passes through the branch instruction stage S40, the measurement stage S20, and the positioning device switching stage S30 once. Then, as will be described later, each time each carrier 3 passes through the branch instruction stage S40,
The number of revolutions written in the ID card 12 is rewritten and updated by adding one to the value.

On the measuring stage S20 shown in FIG. 2, each time the transport vehicle 3 is carried in, each wheel 5 of the transport vehicle 3
The distance from the reference plane 14 is measured by the distance measuring sensor 15 corresponding to. That is, in the measurement stage S20, when the carrier 3 is positioned and stopped as shown in FIGS. 2 and 4, the measurement control device 17 transmits all the contents written to the ID card 12 via the communication devices 11 and 16.
That is, the data of the number of revolutions of the transport trolley 3, the average distance measurement data for each wheel 5, and the wear amount data for each wheel 5 are read out, and these information are taken into the measurement control device 17 (steps S1 and S2 in FIG. 4). , S3). Then, the distance to the reference plane 14 is measured by each distance measuring sensor 15 as described above (step S4).

In the next step S5 of FIG.
The number of turns written in 2 is determined, and the number of turns is “0”.
That is, when the transport trolley 3 is used for the first time in the vehicle body assembly line 1, the distance measurement data (actually measured values) measured by the respective distance measurement sensors 15 are used as they are by the communication devices 11 and 16.
Average distance measurement data area 12b of ID card 12 via
(Steps S5 and S6).

On the other hand, if the number of laps of the transport vehicle 3 is 1 to 9, the calculation of new average ranging data = (average ranging data × number of laps + actual measurement value) / (number of laps + 1) is performed. The obtained new average distance measurement data for each wheel 5 is transmitted to the ID card 1 via the communication devices 11 and 16.
The data is written in the average distance measurement data area 12b and updated (steps S7 and S8).

When the number of laps is 10 or more, the new wear amount data = (average distance measurement data)-(actual measurement value) is calculated, and the new wear amount data for each wheel 5 is transmitted to the communication device. The data is written and updated in the wear amount data area 12c of the ID card 12 through the steps 11 and 16 (step S).
9, S10).

As described above, the latest number of laps, average distance measurement data, and wear amount data are always recorded on the ID card 12 attached to each carrier 3.

On the other hand, the carrier 3 having completed the measurement at the measurement stage S20 travels to the next positioning device switching stage S30. In this positioning device switching stage S30, as shown in FIG. 1, since the type control data of the vehicle body parts W to be mounted on the transport carriage 3 in the next component loading stage S11 is grasped by the positioning control device 20, the positioning is performed. The control device 20 gives a command to the drive unit 10 to move the locate pin 9 via the moving mechanism 8 in FIG.
Is moved, whereby the position of each locate pin 9 is switched to a position corresponding to the vehicle body component W of the corresponding type.

At this time, the positioning control device 20 operates as shown in FIG.
As shown in FIG. 5, the wear amount data for each wheel 5 written in the ID card 12 of the transport trolley 3 is read out via the communication devices 11 and 21 (step S1 in FIG. 5).
1) The average wear amount data of the left and right front wheels and the average wear amount data of the left and right rear wheels are individually calculated based on the wear amount data (step S12 in FIG. 5). The communication device 21 provided in the positioning device switching stage S30 is the same as the communication device 16 in the measurement stage S20.

Then, after adding the above-mentioned average wear amount data to the position command value to be given from the positioning control device 20 to the drive unit 10 and correcting the position command value, the drive unit 10 controls the work positioning device 7 of FIG. Each locate pin 9 is moved via the moving mechanism 8 (Step S13 in FIG. 5). As a result, the position of the locate pin 9 to be finally positioned is corrected at least in the vertical direction according to the wear amount of each wheel 5, and the above-mentioned influence of the wear of the wheel 5 on the positioning accuracy of the vehicle body part W is avoided. Is done.

In this way, the transport trolley 3 in which the position of the locate pin 9 of the work positioning device 7 is switched according to the type of the body component W travels to the component loading stage S11,
After mounting and positioning a predetermined body part W, each assembly step S1 to S9 is circulated.

After the above-described assembly steps S1 to S9, the transport cart 3 is empty when the vehicle body parts W are delivered to the drop lifter or the like at the component unloading stage S12, and the empty transport cart 3 branches. Move to instruction stage S40.

In this branch instruction stage S40, the operation shown in FIG.
As shown in FIGS. 2 and 6, the branch control device 19 reads out the number of turns written on the ID card 12 of the transport trolley 3 via the communication devices 11 and 18, adds 1 to the number of turns, and adds the ID to the number of turns. While the number of laps of the card is rewritten and updated (step S21 in FIG. 6), the wear amount data for each wheel 5 similarly written in the ID card 12 is read (step S22 in FIG. 6).

Then, the difference between the wear amounts of the left and right front wheels and the difference between the wear amounts of the left and right rear wheels are calculated individually (step S23 in FIG. 6), and the difference between the respective wear amounts is set in advance. It is determined whether the transport vehicle 3 can be continuously used (step S24 in FIG. 6) by comparing with the allowable limit value. If the difference between the wear amounts of at least one of the front and rear wheels is, for example, 0.3 mm or more, the branch control device is used. 19 issues a branch instruction to the carrier 3 (step S25 in FIG. 6).

Even if the difference between the wear amounts of the front and rear wheels is less than 0.3 mm, if the wear amount of any one of the front and rear wheels is, for example, 3.0 mm or more, the branch control device 19 is operated in the same manner as described above. Issues a branch instruction to the carrier 3 (steps S24, S26, S27 in FIG. 6). This branch instruction is
If the wheel 5 is greatly worn and the carrier 3 is continuously used, the positioning accuracy of the vehicle body component W is greatly affected, and it is determined that maintenance is necessary. Then, the transport trolley 3 to which the branch instruction has been issued is the branch unit 2 in FIG.
From 2, it is turned to the trolley maintenance stage S50 to perform maintenance such as wheel replacement.

As described above, according to the present embodiment, the carriage 3
If the wear of the wheels 5 is within the allowable limit, the position of the locate pin 9 of the work positioning device 7 is corrected accordingly. The branching is performed, the continuous use is stopped, and the vehicle is moved to the carriage maintenance stage S50. Therefore, it is possible to eliminate the influence of the wear of the wheels 5 on the positioning accuracy of the vehicle body part W.

Here, in the above-described embodiment, an example in which the pair of left and right locating pins 9, 9 are moved by the common moving mechanism 8, as shown in FIG. 2, has been described. 8 may be provided.

[0037]

As described above, according to the present invention, a measuring step for measuring the wear amount of the wheels of the transport vehicle is provided on the transport track, and the transport vehicle is provided with a storage means. While the wear amount data obtained by the measurement is newly written in the storage means each time, in the switching step, the wear amount data stored in the storage means of the carrier is read out each time and the wear amount data is read based on the wear amount data. By correcting the position of the work positioning means, the influence of the wear of the wheels of the transport vehicle on the positioning accuracy of the vehicle body parts is eliminated, and the positioning accuracy of the vehicle body parts is greatly improved as compared with the related art.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view of a vehicle body assembly line showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a measurement stage and a transport trolley.

FIG. 3 is a conceptual explanatory view of an ID card attached to a transport trolley.

FIG. 4 is a flowchart of a processing procedure in a measurement stage.

FIG. 5 is a flowchart of a processing procedure in a positioning device switching stage.

FIG. 6 is a flowchart of a processing procedure in a branch instruction stage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Body assembly line 2 ... Rail (transportation track) 3 ... Conveyor truck 5 ... Wheel 7 ... Work positioning device 8 ... Moving mechanism 9 ... Locating pin (work positioning means) 10 ... Drive unit 11 ... Movable communication device 12 ... ID card ( 15: Distance measuring sensor 16: Fixed side communication device 17: Measurement control device 19: Branch control device 20: Positioning control device S1 to S9: Assembly stage S20: Measurement stage (measuring process) S30: Positioning device switching stage ( Switching step) S40: Branch instruction stage (branch instruction step) S50: Truck maintenance stage W: Body parts

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-239811 (JP, A) JP-A-53-6061 (JP, A) JP-A-1-184510 (JP, A) JP-A-2- 286478 (JP, A) JP-A 1-132487 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23P 21/00 303 B62D 65/00 G05D 1/02

Claims (1)

(57) [Claims] 1. A vehicle body having a work positioning means capable of adjusting a position in a vertical direction, a body part is positioned on the basis of the work positioning means, and the carriage is caused to travel along a conveyance track. In a vehicle body assembling process on a transport track, predetermined processing or work is performed on a vehicle body component positioned on the basis of a work positioning means. In a method for positioning a body part by a transport vehicle in which a vertical position of a positioning means is changed, a measuring step of measuring a wear amount of wheels of the transport vehicle on the transport track is provided, and the transport vehicle has a storage means. Is provided, and the wear amount data obtained by the measurement in the measurement step is newly described each time. Writing in the means, wherein in the switching step, the wear amount data stored in the storage means of the carriage is read each time and the position of the work positioning means is corrected based on the wear amount data. Method of positioning vehicle body parts.