JP2605926B2 - Work receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a shuttle bar type transport device which is mounted on a shuttle bar based on a relative movement of a receiving member with respect to a shuttle bar which has stopped moving forward. A work for receiving the work from the shuttle bar and positioning the work at a predetermined position by fitting the receiving member to a predetermined portion of the work that has been conveyed and conveyed from below, and supporting the work by the receiving member. It relates to a receiving device.

(Prior Art) As a shuttle bar type transfer apparatus, for example, there is a shuttle conveyor used in an automobile body assembly line shown in FIG.

In the drawing, reference numeral 1 denotes a shuttle conveyor. The shuttle conveyor 1 includes a shuttle bar 2 composed of two long plate members arranged side by side and connected to each other in a ladder shape, and a schematic center of the shuttle bar 2. And a shuttle bar driving device 3 fixed on the floor below the section, wherein the shuttle bar 2 is supported and guided by a number of support rollers (not shown) so as to be able to advance and retreat in the left-right direction in the figure. ing.

In addition, the shuttle bar driving device 3 drives the pinion 4 by a motor (not shown) to rotate the shuttle bar 2 through a rack 5 fixed along the shuttle bar 2 and meshing with the pinion 4 by an arrow in the drawing. As shown, it can be moved forward and backward, and the distance of the forward and backward movement is
The contact between the two stopper plates 6 fixed to the center of the shuttle bar 2 and the stopper block 7 fixed to the floor surface makes the pitch distance between the work stations denoted by reference numerals # 0 to # 9 equal to the pitch distance. can do.

On the shuttle bar 2, fingers (not shown) capable of fitting the vehicle body 8 during or after assembly to a predetermined portion thereof and positioning and holding the same with respect to the shuttle bar are provided at intervals equal to the pitch distance. It is erected at a location.

On the other hand, the work station # 0 has a loader (not shown) for placing the body parts on the fingers of the shuttle bar 2, and the work station # 9 has a loader (not shown) from the shuttle bar 2 of the assembled car body 8. An unloader (not shown) is installed for unloading, and each work station # 1 to # 1
9 is provided with a vehicle receiving device 9 as a work receiving device for receiving the vehicle body 8 from the shuttle bar 2 (only the work stations # 7 to # 9 are shown in the figure, and the others are omitted).

Here, each of the vehicle body receiving devices 9 raises and lowers the jig base 12 that supports a plurality of columns 11 each having a tapered locating pin 10 erected as a receiving member with the air cylinder 13 with respect to the shuttle bar 2. Based on such a function, the column 11 is raised, and the fins of the shuttle bar 2 are placed on the shuttle bar 2 and the shuttle bar 2 is transferred from the previous work station to the work station by the forward movement and stop of the shuttle bar 2. The locating pins 10 on the columns 11 are inserted from below into the locating holes at predetermined positions on the bottom of the vehicle body 8 stopped and fitted, and the vehicle body 8 is supported by the columns 11 so that the vehicle body 8 is supported. It can be received from the shuttle bar 2 and lifted to be positioned at a predetermined position of each work station.

And the vehicle body 8 positioned in this way includes
Work such as assembly of vehicle body parts assigned to the work station is performed.

In addition, the vehicle body receiving devices 9 installed in the work stations # 1 to # 8 lower the support 11 with the air cylinder 13 with respect to the shuttle bar 2 which has moved backward and stopped, and the vehicle body supported by the support 11 The vehicle body 8 can be delivered to the shuttle bar 2 by placing the vehicle body 8 on the finger of the shuttle bar 2.

Therefore, according to the above line, the work station # 0
, While sequentially transporting the body parts placed on the shuttle bar 2 by the loader to the work stations # 1 to # 9, sequentially assembling other body parts at predetermined positions of the body parts, and And the vehicle body 8 can be picked up from the shuttle bar 2 by the unloader at the work station # 9 and carried out of the line.

(Problems to be Solved by the Invention) Since the shuttle bar 2 is made of an extremely long steel material, its entire length greatly expands and contracts due to thermal expansion and thermal contraction caused by a change in ambient temperature (for example, the shuttle bar 2). If the total length of the steel is 100 meters and the temperature varies from -10 ℃ to 30 ℃, the coefficient of thermal expansion of the steel material is about 1 × 10 ^-5 /
° C, so the difference in total length due to expansion and contraction is about 40 mm).

On the other hand, the above-mentioned conventional vehicle receiving device 9 is installed on the floor of a work station fixed to the ground via a foundation, and since the vehicle body 8 needs to be positioned at a predetermined position of the work station, the locating pin 10 is used. Standing upright
The horizontal position of 11 is fixed with respect to the floor of the work station, and the column 11 cannot be moved in the direction in which the shuttle bar 2 extends.

For this reason, in the conventional vehicle receiving device 9 described above, the stop position of the shuttle bar 2 is determined by the stopper plate 6 at the center and the stopper block 7 on the floor side.
As it is, the shuttle bar 2 expands and contracts, and is positioned on the finger of the shuttle bar 2 that has moved forward and stopped with respect to the locate pin 10 on the support column 11, particularly at the work station near both ends of the shuttle bar 2. The position of the car body 8 and thus the locating pin of the car body 8
In some cases, the location of the locating hole that fits with the position 10 is excessively shifted, and the tapered locating pin 10 cannot be fitted into the locating hole. In such a case, the vehicle body 8 must be securely received and accurately positioned. Therefore, as shown in the figure, a rough guide 14 having an upper space is provided on the jig base 12 so as to be integrated with the support 11, and the jig base 12 is provided.
When the vehicle rises, firstly, the positional deviation of the vehicle body 8 is corrected to some extent by the rough guide 14, and then the locate pin 10 is raised to the locate hole.

When the rough guide 14 is not provided, as shown in FIG. 7, the fixing position of each finger 15 with respect to the shuttle bar 2 is set to a position near the end shown by a two-dot chain line in winter,
In the summer, it is moved to the position near the center indicated by the dashed line in the figure, and in the spring and autumn, it is moved to the intermediate position shown by the solid line in the figure. Had been prevented.

However, in the above-described method, when the rough guides 14 are provided, there is a problem that the interval between the rough guides 14 is too wide or too narrow depending on the type of vehicle when a plurality of types of vehicles are mixed-produced on the vehicle body assembly line. When the 15 fixed positions are moved, there are problems in that the number of fingers 15 is large, so that the man-hour for the movement is increased, and it takes extremely time to determine an appropriate fixed position.

The present invention is to provide a work receiving apparatus that advantageously solves such a problem.

(Means for Solving the Problems) The work receiving device of the present invention is mounted on the shuttle bar based on the relative elevation of the receiving member with respect to the shuttle bar stopped by moving forward of the shuttle bar type transfer device. Receiving the work from the shuttle bar and positioning the work at a predetermined position by fitting the receiving member to a predetermined portion of the work that has been conveyed from below and supporting the work by the receiving member. Finding the shift amount of the stop position of the work due to the expansion and contraction of the shuttle bar based on changes in the ambient temperature,
A stop position shift amount output means for outputting a signal corresponding to the stop position shift amount, and moving the receiving member in the direction in which the shuttle bar extends in accordance with the stop position shift amount of the work based on the output signal. And a receiving position correcting means.

(Operation) In such an apparatus, first, the stop position shift amount output means obtains the shift amount of the stop position of the work due to the expansion and contraction of the shuttle bar based on the change in ambient temperature, and corresponds to the stop position shift amount. A signal is output, and then the receiving position correcting means moves the receiving member in the direction in which the shuttle bar extends in accordance with the stop position deviation amount of the workpiece based on the output signal, and then moves forward to stop the shuttle. Based on the relative elevation of the receiving member with respect to the bar, the receiving member is fitted from below into a predetermined portion of the work placed and transported on the shuttle bar, and the receiving member supports the work. By receiving the workpiece from the shuttle bar, the receiving position correcting means moves the receiving member to the original position in the direction in which the shuttle bar extends, and then moves the receiving member to the original position. Position the workpiece in place.

Therefore, according to the device of the present invention, even if the stop position of the work is shifted due to the expansion and contraction of the shuttle bar based on the change in the ambient temperature, a rough guide is provided or the fixed position of the finger to the shuttle bar is moved. Work can be reliably received and accurately positioned from the shuttle bar without having to perform multi-mix production of multiple models on the body assembly line, and a large amount of movement is required for moving each finger. The number of steps and time required can be eliminated.

According to the present invention, even when the stop position of the finger is shifted due to the expansion and contraction of the shuttle bar, the work can be reliably transferred to the shuttle bar by performing the same procedure as described above.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a layout of an automobile body assembly line to which an embodiment of a work receiving device according to the present invention is applied. In FIG. 1, parts similar to those in the related art are denoted by the same reference numerals.

That is, in the drawing, reference numeral 1 denotes a shuttle conveyor. This shuttle conveyor 1 includes a long shuttle bar 2 and a shuttle bar driving device 3 fixed on a floor below a substantially central portion of the shuttle bar 2. Here, the shuttle bar 2 is supported and guided so as to be able to move forward and backward in the left and right directions in the figure.

In addition, the shuttle bar driving device 3 can move the shuttle bar 2 forward and backward as indicated by the arrow in the figure by rotating the pinion 4 to move the shuttle bar 2 through a rack 5 that meshes with the pinion 4. The distance of movement is adjusted by the contact between the two stopper plates 6 fixed to the center of the shuttle bar 2 and the stopper block 7 fixed to the floor surface between the work stations indicated by reference numerals # 0 to # 9 in the drawing. It can be equal to the pitch distance.

On the shuttle bar 2, fingers (not shown) capable of fitting the vehicle body 8 during or after assembly to a predetermined portion thereof and positioning and holding the same with respect to the shuttle bar are provided at intervals equal to the pitch distance. It is erected at a location.

On the other hand, the work station # 0 has a loader (not shown) for placing the body parts on the fingers of the shuttle bar 2, and the work station # 9 has a loader (not shown) from the shuttle bar 2 of the assembled car body 8. An unloader (not shown) is installed for transport, and each work station # 1 to # ♯
9 is provided with a body receiving device 16 as a work receiving device for receiving the vehicle body 8 from the shuttle bar 2 (only the work stations # 1, # 2 and # 8, # 9 are shown in the figure, and the others are shown). Omitted).

Here, as shown in FIG.
A plurality of rectangular coordinate robots 18 as receiving position correction means, each supported by a frame 17 fixed to the floor surface
And a robot controller 19 using a microcomputer for controlling the operation of the robots 18, as shown in FIG.
Based on a command signal from the robot controller 19, the support bar 11 having a tapered locating pin 10 as a receiving member attached to a wrist located at the upper end of the robot 18 extends the shuttle bar 2. It can be moved horizontally in the existing direction and in a direction perpendicular thereto, and can be moved up and down.

Therefore, this vehicle body receiving device 16
11 is lifted to a predetermined position on the bottom of the vehicle body 8 which is placed on the finger of the shuttle bar 2 and is transferred from the previous work station to the work station by the forward movement and stop of the shuttle bar 2 and stopped. By inserting the locating pins 10 from below into the locating holes and fitting the locating pins 10 and supporting the vehicle body 8 on the columns 11, the vehicle body 8 is received from the shuttle bar 2 and lifted, and the predetermined position of each work station is determined. When there are a plurality of types of the vehicle body 8 to be assembled, each of the locate pins 10 is horizontally moved below the position of the locate hole according to the type of the vehicle body 8 that has come to the stop position. By performing the above operation, each locating pin 10 is securely fitted into each locating hole of the vehicle body 8,
The received vehicle body 8 can be reliably positioned.

Incidentally, the vehicle body receiving devices 16 installed in the work stations # 1 to # 8 lower the column 11 with respect to the shuttle bar 2 which has moved backward and stopped, and the vehicle body 8 supported by the column 11 The vehicle body 8 can also be delivered to the shuttle bar 2 by placing it on the above-mentioned fingers of the second vehicle 2.

Further, here, on the floor (left side in FIG. 1) of the end of the shuttle bar 2 on the side of the work station # 9, the detected member 2a fixed to the end of the shuttle bar 2 A laser distance sensor 20 as stop position deviation amount output means capable of detecting a distance in a non-contact manner is fixed, and the distance sensor 20 and the robot control device 19 of each of the vehicle body receiving devices 16 are shown in FIG. As shown in the figure, the vehicle receiving devices 16 and the work computers of the work stations are connected to host computers 21 for instructing work contents and operation timings of a large number of welding robots (not shown).

According to such an automobile body assembly line, the body parts placed on the shuttle bar 2 by the loader at the work station # 0 are transferred to the work stations # 1 to # 4 by the instruction from the host computer 21 in the same manner as the conventional line.
While sequentially transporting the vehicle body to # 9, other vehicle body parts are sequentially assembled at predetermined positions of the vehicle body part to assemble the vehicle body 8, and the vehicle body 8 is picked up from the shuttle bar 2 by the unloader at the work station # 9. Out of the line.

In addition, since a plurality of types of vehicle bodies 8 can be positioned at each work station as described above, mixed production of a plurality of types of vehicles can be easily performed.

Then, shuttle bar 2 based on the change of ambient temperature
The shift of the stop position of the vehicle body 8 due to the expansion and contraction of the vehicle will be dealt with as follows.

That is, as shown in FIG. 1, the length from the center position C to both ends of the shuttle bar 2 at a predetermined reference temperature is L,
Assuming that the current amount of expansion and contraction of the length L based on the change in temperature from the reference temperature is ΔL, here the distance sensor
As shown in FIG. 3, the host computer 20 detects the distance from the reference member 2a of the shuttle bar 2 that has reached the forward limit position to the distance sensor 20, and outputs a signal corresponding to the distance to the host computer.
Output to 21.

Next, the host computer 21 receives the signal, obtains the expansion / contraction amount ΔL from the difference between the distance at the current temperature based on the signal and the distance at the reference temperature,
From the ratio of ΔL and L, the following formula is used to determine the amount of deviation of the stop position of the vehicle body 8 at each work station, and hence each robot.
The movement amount ΔL _n of the locating pin 10 in the direction in which the shuttle bar 2 extends due to 18 is generated. Where n is shuttle bar 2
The body 8 on which the fingers are positioned and held is defined as 1, 2, 3,... In order of being closer to both ends of the shuttle bar 2, and L _n is the shuttle bar from the reference position P of the nth body 8 to the center position C. Length at the reference temperature of 2.

ΔL _n = ΔL × L _n / L After that, the host computer 21 outputs a movement amount signal corresponding to each of the movement amounts ΔL _n to the robot controller 19 of the work station that receives the n-th vehicle body 8, and Each robot control device 19 gives a command signal to the robot 18 of each vehicle body receiving device 16 based on the movement amount signal, and moves each strut 11 in the extending direction of the shuttle bar 2 as shown in FIG.
Movement amount [Delta] L _n only is horizontally moved from the predetermined horizontal position (shown in the drawing phantom) in the reference temperature with respect to the reference position Q of the work station, the position of the locating pin 10, below each locator hole of the vehicle body 8 has stopped After the position is corrected, the columns 11 are lifted so as to receive the vehicle body 8, and when the columns 11 lift the vehicle body 8 from above the shuttle bar 2, the columns 11 are horizontally moved to the predetermined horizontal position. Thus, the reference position P of the vehicle body 8 is made to coincide with the reference position Q of the work station, and automatic work on the vehicle body 8 is enabled.

Therefore, according to the apparatus of this embodiment, even if the stop position of the vehicle body 8 shifts due to expansion and contraction of the shuttle bar 2 due to a change in ambient temperature, a rough guide is provided or the finger 15 is fixed to the shuttle bar 2. Since the vehicle body 8 can be reliably received from the shuttle bar 2 and accurately positioned without shifting the position, mixed production of a plurality of types of vehicles on the vehicle body assembly line can be facilitated. A great deal of man-hour and time for moving the finger 15 can be eliminated.

In the above work stations # 1 to # 8, the body 8
In the delivery of the support 11 from the support 11 to the shuttle bar 2, the support 11 supporting the vehicle body 8 is previously moved in the extending direction based on the expansion and contraction of the shuttle bar 2 in the same procedure as described above. , Whereby the vehicle body 8 can be securely fitted and placed on the finger 15 of the shuttle bar 2 which has been retracted and stopped.

FIGS. 4 and 5 show another embodiment of the present invention. In the embodiment shown in FIG. 4, the same vehicle body receiving device 16, robot control device 19 and host device as those in the above embodiment are used. Although the computer 21 is provided, the detected member is located in the vicinity of each vehicle body mounting position of the shuttle bar 2.
2b is fixed, and includes a position sensor 22 on the floor of each work station, for example, which can detect the movement distance of the detected member 2b by a change in magnetism generated by the detected member 2b. Each robot controller 19 outputs the vehicle body 8 at the work station based on the output signal from the
5, the position of the locating pin 10 is horizontally moved by the amount of the positional deviation. In the embodiment shown in FIG. 5, the vehicle body receiving device 16 and the robot control Device 19 and host computer 21
A temperature sensor 23 for detecting an air temperature on the shuttle bar 2 or on a floor near the shuttle bar 2, and a host computer 21 based on a signal output from the temperature sensor 23 corresponding to the current air temperature. Calculates the amount of displacement of each of the vehicle bar mounting positions of the shuttle bar 2, and gives the calculation result to each of the robot controllers 19 in the same manner as in the first embodiment. The position of the locate pin 10 is moved horizontally based on the amount.

Therefore, according to these embodiments, the same effect as the previous embodiment can be obtained.

As described above, the present invention has been described based on the illustrated example, but the present invention is not limited to the above-described example.
It can be applied to other works.

(Effect of the Invention) Thus, according to the work receiving device of the present invention, even if the stop position of the work is shifted due to the expansion and contraction of the shuttle bar due to a change in ambient temperature, a rough guide is provided or the finger to the shuttle bar is provided. The work can be reliably received and accurately positioned from the shuttle bar without moving the fixed position of the vehicle, so that mixed production of multiple models on the body assembly line can be facilitated, and A great deal of man-hour and time for moving the finger can be eliminated.

According to the present invention, even when the stop position of the finger is shifted due to the expansion and contraction of the shuttle bar, the work can be reliably transferred to the shuttle bar by performing the same procedure as described above.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a layout of an automobile body assembly line to which an embodiment of a work receiving device of the present invention is applied, and FIG. 2 is a schematic diagram showing a vehicle body receiving device installed at a work station of the vehicle body assembly line. FIG. 3 is a block diagram showing a control system of the apparatus of the above embodiment, FIGS. 4 and 5 are block diagrams showing a control system in another embodiment of the present invention, and FIG. FIG. 7 is a schematic diagram illustrating a layout of an automobile body assembly line including a work receiving device, and FIG. 7 is a schematic diagram illustrating a state where the vehicle body is mounted on a shuttle bar in the vehicle body assembly line. 2 Shuttle bar, 8 Body 11 Support, 16 Body receiving device 20 Distance sensor 22, Position sensor 23 Temperature sensor

Claims (1)

(57) [Claims] 1. The shuttle bar-type transfer device is mounted on the shuttle bar and conveyed based on the relative movement of the receiving member (11) with respect to the shuttle bar (2) stopped by moving forward. A work receiving apparatus for receiving the work from the shuttle bar and positioning the work at a predetermined position by fitting the receiving member to a predetermined portion of the work (8) from below and supporting the work by the receiving member. Stop position shift amount output means (20, 22, 23) for obtaining a shift amount of a work stop position due to expansion and contraction of the shuttle bar based on a change in ambient temperature and outputting a signal corresponding to the stop position shift amount. Receiving position correcting means (16) for moving the receiving member in the direction in which the shuttle bar extends in accordance with the work stop position deviation amount based on the output signal. When, and providing a, workpiece receiving device.