JPS61248815A - Operation device for synchronized conveyors - Google Patents

Abstract

PURPOSE:To enable correction of a teaching amount to be accomplished in real time by configurating a device in such a way that slippage between synchronized conveyors is detected by non-contact sensors, and a mounting means is corrected by the teaching amount on the basis of the slippage detected in synchronized conveyors for an automobile assembly line. CONSTITUTION:When both an object on No.1 travelling conveyor 1 and another object on No.2 travelling conveyor 2 arrive at a relative position which is set in advance, a position slip detecting means 7 is actuated so as to detect the slippage D2L, D2W, and D2H in length, width, and height allowing it to be sent to a teaching amount correction means 8. Then, the teaching amount correction means 8 allows the teaching amount T.D which is inputted from a teaching means 6 in advance, to be corrected by the slippage D2 in position permitting a correction drive amount KL to be inputted to a mounting device drive means 9. Then, the mounting device drive means 9 actuates a mounting device 5 on the basis of the correction drive amount KL permitting No.2 object 3 to be installed on No.1 object 2. This configuration enables correction for the teaching amount to the mounting device to be accomplished in real time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique for correcting the amount of teaching in an article assembly line using a synchronous conveyor device.

[Conventional technology]

2. Description of the Related Art In automobile assembly lines and the like, articles are assembled using multiple conveyors. For example, the body of a car is transported by an overhead conveyor, and the engine is transported by an underfloor conveyor. Conventionally, the conveyor was stopped at the point where the body and engine were attached to perform the attachment work.

[Problem that the invention seeks to improve]

If the conveyor is stopped and the assembly is performed as in the past, productivity will be poor. Therefore, in order to perform attachment without stopping the conveyor, it has been proposed to drive both conveyors synchronously, provide an engine attachment device on the underfloor conveyor, and move the attachment device by the required amount of instruction. However, since the position of the body supported by the overhead conveyor fluctuates, a deviation in the reference position occurs between the body and the component mounting device even though the overhead conveyor and the underfloor conveyor are synchronized. If the relative relationship between the engine and the body deviates from the standard, the amount of engine movement will be calculated in advance, assuming the positional relationship with the body is constant, and will be added to the mounting device as a taught amount. Even if the equipment is moved, the engine cannot be installed, so it is necessary for the operator to take action.

The present invention has been made in view of the problems of the prior art, and it is possible to compensate for positional deviation between articles to be assembled on a synchronous conveyor and correct the teaching amount in real time without stopping the assembly device. The purpose is to provide equipment.

[Means for solving problems]

As shown in FIG. 1, the synchronous conveyor working device of the present invention includes a first traveling conveyor 1 that continuously conveys a first object 2 at a predetermined pitch, and a first traveling conveyor 1 that is driven in synchronization with the first traveling conveyor 1 to convey the first object 2 continuously at a predetermined pitch. A second traveling conveyor 4 continuously conveys the second object 3 to be attached to the second object 2 at a predetermined pitch. A mounting device 5 that performs mounting work on the object 1;
attachment device 5 necessary for attaching the second object 3 on the traveling conveyor 4 to the first object 2 on the first traveling conveyor 1;
teaching means 6 for teaching in advance the amount of drive of the first traveling conveyor 1 and second traveling conveyor 4; means 7 for detecting the relative positional deviation between the first traveling conveyor 1 and the second traveling conveyor 4 without contact; and the mounting device based on the amount of deviation. The attachment of the second object to the first object by means of means 8 for correcting the teaching drive amount in the horizontal and vertical directions, and means 9 for driving the attachment device 5 by the corrected teaching amount.

〔Example〕

In the following, an example will be described in which the idea of the present invention is applied to the work of assembling an automobile body and an engine.

In Fig. 2.3.4, an overhead conveyor 12 is attached to a building beam 10 of an automobile assembly factory, and a third automobile body 16 is moved from the overhead conveyor 12 by a hanger 14.
As shown in the figure, they are suspended at a predetermined pitch.

A loop-shaped underfloor conveyor 20 is provided below the overhead conveyor 12. The underfloor conveyor 20 includes a loop-shaped trolley duct 2 formed below and above the floor surface 22.
It has a chain 24 running inside 2', and the chain 24
is sprocket 26a.

26b. The sprocket 26a is driven by a drive mechanism (not shown) for driving the overhead conveyor 12, so that synchronous movement of the underfloor conveyor 20 and the overhead conveyor 12 is realized. Towing pins 28 extend upright from the chain 24 of the underfloor conveyor at intervals that match the vehicle body on the overhead conveyor 12, and to the towing pins 28, a truck 32 of an engine mounting device 30 is fixed. . Therefore, as the chain rotates, the cart 32 runs along the conveyor loop on the floor 22.

In addition to the truck 32, the engine mounting device 30 includes an elevating plate 3
4, a longitudinally movable plate 36, and a widthwise movable plate 38. The lifting plate 34 is a hydraulic cylinder 40 for driving in the height direction.
It can be moved up and down in the height direction (H). The longitudinally movable plate 36 is connected to a longitudinally driving hydraulic cylinder 42 and is horizontally movable in the longitudinal direction (L).

Further, the width direction moving plate 38 is connected to a hydraulic cylinder 44, and is horizontally movable in the width direction (W). With this configuration, the engine 46 mounted on the plate 38 can be moved independently in the height direction, length direction, and width direction by selectively driving the respective hydraulic cylinders 40, 42, and 44. It becomes.

An antenna 50 is provided upright and cantilevered from the truck 32 toward the overhead conveyor 10.

As shown in FIG. 6, the antenna 50 consists of a sleeve 56 provided on a mounting piece 32' extending in the L direction from the truck 32, and an antenna rod 58 provided slidably in the height direction within the sleeve 56. Note that the antenna rod 58 is supported within the sleeve 56 by a linear bearing (not shown).

Non-contact deviation detection sensors T0, 72, and 74 are provided at the upper end of the antenna rod 58 in the L direction, W direction, and H direction, respectively. These sensors 70°72,
74, it is possible to detect the deviation of the antenna rod 58 from the reference position in the L direction, W direction, and H direction, that is, a relative positional shift caused by a specific body and engine.

L direction deviation detection sensor 70, W direction deviation detection sensor 72
, the H direction deviation detection sensor 74 is located in the recess 16' formed in the lower surface of the body 16 by pulling up the antenna rod 58 immediately before assembly. recess 16
'Three reference planes 16t perpendicular to the beam, W, and H directions
, 16w, 16n (Figures 5 and 6)
The sensors To, 72, and 74 are located on the surface 16L, respectively.
16w and 16H, and the distance between each sensor and the opposing reference surface is XL IXw,
Detect Xs+.

These deviation detection sensors 70, 72, and 74 are reflective photoelectric sensors and all have the same structure. Therefore, to explain the sensor 70, as shown in FIG. 7, the sensor 70 consists of a light projecting part 70a and a light receiving part 70b, and a voltage output proportional to the distance Xt in the vertical direction from the opposing wall surface 16L is applied to the light receiving part 70b. (See Fig. 8 (a)). In Fig. 7, if the broken line 16L' is the position of the wall surface at the reference position, and the distance from the sensor 70 at this time is XL', then XL-XL' is the distance in the L direction. , the deviation caused by the specific body and engine will be 1) 2L. In order to extract a signal according to this deviation, the optical receiver 70b uses an operational amplifier 70.
The output voltage V6 (eighth
A set voltage corresponding to (Fig.) is applied. Therefore, the output of the operational amplifier 70c shows the actual deviation D from the reference position.
A voltage corresponding to 2L is obtained (FIG. 8(0)).

The structure is the same for the W direction and H direction sensors,
A voltage signal is obtained that corresponds to the distance between the opposing wall surfaces 16w and 16H and the deviation D2@, 02N from the reference position.

FIG. 9 shows the hydraulic circuit for the driving hydraulic cylinder in the mounting device 30 and the electric circuit for driving the hydraulic circuit; these are shown for one hydraulic cylinder, but for the other two.
The same applies to the two hydraulic cylinders, each of which is provided independently. The hydraulic cylinder y4o, 42 or 44 includes a piston 80 and a piston rod 81, and hydraulic chambers 82, 83 are formed on both sides of the piston. Hydraulic chambers 82, 83
Hydraulic pressure is selectively supplied from a 2-position hydraulic pressure switching valve 84 to the piston 8 by selecting solenoids 84a and 84b.
0 moves left and right, moving plates 36 and 38 in Figure 2.4
, 34 Nori, W.

Motion in the H direction is obtained. In addition, 85 is a check valve, 86
is a strainer, 87 is a hydraulic pump, 89 is a motor, 90
is an oil reservoir, and since these are well-known elements of a hydraulic circuit, a detailed explanation will be omitted. Reference numeral 92 denotes a flow rate control valve, which controls the amount thereof, that is, the flow rate to the hydraulic chamber 82 or 83, by the current applied to the solenoid 94, and controls the speed in the W and H directions as described later. .

The control circuit is configured as a microcomputer system, which controls the hydraulic circuit according to the program shown in the flowchart described later, performs the engine installation work as instructed, and corrects the taught amount according to the detected deviation. . As in the case of the hydraulic circuit, only the control circuit for one hydraulic cylinder is shown in FIG. 9, but the other hydraulic cylinders are similarly constructed. Deviation detection sensor 70,
72 or 74 is an analog-to-digital (A/D) converter 1
(input via 00) connected to 102, L, W.

A digital signal corresponding to the deviation is input into the computer in each direction of H and H.

On the other hand, a position sensor 104 is provided to detect the position of the piston rod 81 of each hydraulic cylinder 40, 42 or 44. This position sensor 104 is shown in FIG. 10 as an L direction position sensor, and has a detection member 104a and a detection piece 104b.
Consists of a combination of The sensing member 104a is a permanent magnet with alternating N and S poles, and the sensing piece 104b is a Hall element placed close to the permanent magnet, and responds to movement by changing the magnetic field due to the relative positions of the two. A pulse signal is obtained.

The pulse signal from the sensor 104 is connected to the input boat 102 via an up/down counter 106 and connected to the mounting device 30 .

Signals corresponding to the actual position in the W and H directions are input into the computer. 107 is located at a position where the relative positions of the vehicle body 16 on the overhead conveyor 12 and the engine assembly 46 mounted on the mounting device 30 on the underfloor conveyor 20 coincide, for example, as shown by p in FIG. This is a limit switch that detects the arrival of the limit switch, and is used to generate a start signal for operation control by a microcomputer as described later. The input board 102 is connected to a microprocessing unit (MPtl) 10B, a random access memory (RAM) 110, and a read only memory (ROM) 112 via a bus 114. R
A control program, which will be described later, is written in the OM 112, and the MPυ 108 forms a drive signal to the hydraulic circuit according to this program and outputs it to the output boat 116.

The output boat 116 includes flip-flop circuits 118a and 118b as launches, and amplifier circuits 120a and 1.
Solenoids 84a, 8 of the hydraulic switching valve 84 via 20b.
4b.

Furthermore, the output boat 116 is connected to the solenoid 94 of the pressure regulating valve 92 via a pulse oscillator 120 and a digital-to-analog (A/D) converter 122. ROM112
The instruction amount necessary for assembling the engine assembly 46 to the automobile body 16 is stored therein. Such teaching data is configured as shown in FIG. 11, for example, and moves the engine assembly from the origin S0 in the H direction to point SL, then in the L direction to point 82, and finally in the W direction to point S. It is configured as a series of data consisting of a combination of movement direction and movement amount. The reason why such a complicated movement of the engine assembly is necessary is that the body design of recent automobiles has become extremely complex, and the engine assembly cannot be attached to the body simply by moving it in one direction.

ROM 112 has mounting device 3 in accordance with such teachings.
A program has been written to drive the engine and mount the engine assembly. The software configuration of this invention will be explained below with reference to the flowchart of FIG.

When the vehicle body 16 on the overhead conveyor 12 and the engine on the floor conveyor 20 arrive at a predetermined fixed point p (FIG. 3) where the relative positions of the vehicle body 16 and the engine on the floor conveyor 20 almost match, a sensor 107 such as a limit switch detects this. This routine then begins at 200 in FIG. At 202, deviation detection sensors 70 , 72 .

The A/D converter 100 performs A/D conversion of the voltage signals representing the deviations D2L, D2, 02N from the reference position in the L direction, W direction, and H direction from the reference position. The A/D converter IQO includes a multiplexer and sequentially switches the sensors To, 72, and 74 to inputs of the A/D converter, and A/D conversion of the deviation signal from each sensor is performed sequentially. The D-converted value is stored in a predetermined area of RAM 110.

Proceed to the next step 204 and MPo 10B is ROM
Teaching data T, D stored in a predetermined area in 112
.

Perform reading. The teaching data includes moving the engine 46 on the mounting device 30 in the H direction as shown in FIG.
up to 35 then bl in the L direction to S2 and then S3 in the W direction
When moving up to C, a series of data (H.

3; L, , b; W, c). Next 206
Proceed to step , where the number of repetitions, i.e., H, L
, data of the number of divided movements in the W direction are set. This number of times I is 3 in the example of the data above. 208
In step , the repetition count counter C is cleared. At step 209, it is determined whether the counter C has reached the set number of repetitions I.

At first, the answer is No, and the process proceeds to 210. In 210, teaching data is loaded. As described above, the teaching data is made up of pairs of moving direction and moving amount, and such pairs are loaded one by one starting from the first set each time this routine is executed. In the next step 212, it is established whether the direction is W or H based on the direction data of the loaded set of data.

If it is determined in 212 that the direction is L, the control routine for the direction below 213 is executed, and if it is determined that the direction is W, the control routine for the W direction is executed
If the H direction is selected, the flow advances to the H direction control routine 252.

To explain the L direction control routine, if it is determined at 212 that the direction is the forward/backward direction, the program executes 2
In step 13, the moving direction of the piston is determined, and if it is positive, the initial value of the speed is set in step 214. That is,
The MPU 116 applies a signal according to the data to the oscillator 120 based on the desired speed data of the piston 80 of the hydraulic cylinder for movement in the L direction, and the D/A converter 122 forms a current signal according to the speed. , as a result, the flow rate control valve 92
The opening degree can be determined. Next, the program proceeds to step 216 and enters a routine for driving the hydraulic switching valve 84 to move the piston in the positive direction of the teaching data T, D. That is, the MPU 108 uses the output port 116 as
Set the flip-flop 118a. (At this time, the flip-flop 118b is reset, so the amplifier 1
Solenoid 84a of switching valve 84 is energized via 20a, while solenoid 84b is deenergized by resetting flip-flop 118b. Therefore, the hydraulic chamber 82
The hydraulic pressure chamber 83 is connected to a drain, and the piston 80 is positioned so as to move to the right in FIG. It goes without saying that the direction of movement of the piston 80 is to move the L direction moving plate 34 in the plus direction in the L direction. Next, at 218, a loop is performed for a predetermined time to wait for a response from the hydraulic part. In 220, M
The PU 108 reads the workpiece position signal D+ in the direction input as a digital signal from the sensor 104 by the counter 106, and then reads the antenna 50 signal digitized by the A/D converter 100 from the deviation detection sensor 70 at 222. A deviation signal D2L from the reference position in the L direction is input. That is, in advance, the operator pulls up the antenna rod 58 of the antenna 50 to reach the tip #A6.
6 is located within the recess 16' of the body 16. 1. Then, the sensor 70 detects if there is a deviation D2L of the opposing wall surface 16L from the reference position 16L', and the signal from the detection sensor 70 indicates such a deviation from the reference position in the zero direction. be.

The program then proceeds to 224 in FIG. 12, where IKLI is calculated by subtracting the sum of Dl and D2L from the teaching data T and D. Here, IKLI indicates the difference between the taught position and the actual position of the workpiece, and also includes correction for deviation from the reference position. A digital signal corresponding to this IKLI is applied from the output port 116 to the oscillator 120, and the D/A
The converter 122 converts the signal into an analog signal, and the flow rate control valve 9
2 solenoid 94. Therefore, the flow rate control valve 92 has an opening degree depending on the value of KL. That is, when KL is large, that is, when the position of the workpiece (engine) is far from the taught position, the opening degree of the flow control valve 92 is large, the hydraulic pressure inflow speed is large, and the operating speed of the piston 80, in other words, the speed of the moving plate in the L direction. That is, the moving speed of the engine assembly is set high. Then, as the position of the engine assembly comes closer to the taught position, control is performed to reduce the speed of the engine assembly.

As a result of such control, if KL=0, that is, the position of the engine in the L direction matches the taught position, the determination in 226 is Ye.
s, the process proceeds to 228, where the MPo 10B sends a reset signal to the flip-flop 118a from the output boat 116, so that the switching valve 84 takes the neutral position and stops moving in the L direction. At 230, the speed instruction is canceled.

The flow of the program when it is determined at 214 in FIG. 12 to perform L movement in the negative direction is almost the same as in the case of positive movement, and only a number is given to each step and the explanation thereof will be omitted.

W direction control routine 250, H direction control routine 2
The contents of 52 are similar to the forward direction control routines 213-242, and in each routine, the sensors 72 and 74 control the facing closed surfaces 161.1.16. Deviation D2. of the distance XW+XM from the reference value. , 02. After correcting the teaching amount by I, movement processing in the W and H directions by the corrected teaching amount is executed.

When the movement process in the desired direction is completed in this way, the counter C is incremented at step 254, and the process proceeds to 209, where the next movement process is performed. Once the required number of movements have been performed, the process flows from 209 to 256, and a -cycle operation is executed.

〔Effect of the invention〕

In the present invention, a shift in relative position is detected without contact, and the teaching amount is corrected by the amount of shift to perform movement control. Therefore, even if there is a positional shift between the articles on the synchronous conveyor, these articles can be attached without stopping the conveyor, and work efficiency can be improved.

Further, since the relative positional deviation detection means can be operated without contact between the articles on the synchronous conveyor, the structure of the positional deviation detection means can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the present invention; Fig. 2 is a schematic side view of the conveyor device of the invention; Fig. 3 is a schematic top view; Fig. 4 is a schematic front view; Fig. 5 is a top view of the antenna; Figure 6 is a side view of the antenna, Figure 7 is a detailed configuration diagram of the deviation detection sensor, Figure 8 is a graph showing the operation of the deviation detection sensor, Figure 9 is a configuration diagram of the hydraulic circuit and control circuit, and Figure 10 is FIG. 11 is a schematic configuration diagram of a position sensor; FIG. 11 is an explanatory diagram of the configuration of teaching data; FIG. 12 is a flowchart diagram illustrating the operation of the device of the present invention. DESCRIPTION OF SYMBOLS 10... Overhead conveyor, 16... Automobile body, 20... Underfloor running conveyor, 30... Mounting device, 32... Dolly, 34...
Lifting plate, 36...Longitudinal moving plate, 38...
Width direction moving plate, 40, 42, 44... cylinder,
46...Engine, 50...Antenna,? 0
, 72 , 74... displacement detection sensor, 104...
position sensor. 4...Second traveling conveyor 5...Mounting device boiling...Engine field 00. Antenna Fig. 5 70a... Light emitting part voltage Fig. 8

Claims (1)

[Claims] a first traveling conveyor that continuously conveys a first object at a predetermined pitch; and a second traveling conveyor that is driven in synchronization with the first conveyor and continuously conveys a second object to be attached to the first object at a predetermined pitch. a second traveling conveyor; a mounting device that attaches the second object to the first object by driving the second object on the second traveling conveyor; teaching means for teaching in advance the amount of drive of the attachment device required to attach it to the first object on the first traveling conveyor, the relative position between the first traveling conveyor and the second traveling conveyor; A means for detecting a deviation without contact; a means for correcting the teaching drive amount in the horizontal and vertical directions when the second object is attached to the first object by the mounting device based on the deviation amount; and a mounting device by the corrected teaching amount. A synchronous conveyor working device comprising means for driving a synchronous conveyor.