JPH0125660B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is an assembly method in which a workpiece is sequentially conveyed to a plurality of assembly stations in a pitch manner, and each assembly station lifts and supports the workpiece to perform an assembly operation. This invention relates to improvement of a device for conveying workpieces in pitches on a line.

(Prior Art) A so-called lift-and-carry device has been known as a device for lifting and lowering workpieces and conveying pitches on such an assembly line (see, for example, Japanese Patent Application Laid-Open No. 56-3212). This lift and carry device includes a pair of shuttle bars (transfer bars) arranged on both sides of a support base of an assembly station and extending in the arrangement direction (transfer direction) of the assembly station, and a lifting drive device that moves the shuttle bars up and down. , a conveyance drive device that reciprocates the shuttle bar in the conveyance direction with strokes at pitch intervals between the assembly stations, and when the workpiece is on the support stand of each of the assembly stations and the assembly at the assembly station is completed, the shuttle bar is moved. After ascending and placing the work on the shuttle bar,
The shuttle bar advances one pitch to transport the workpiece to the front assembly station, and then descends to place the workpiece on the support of the assembly station, while the lowered shuttle bar moves back one pitch to return to its original position. It was designed to return to .

However, in the above-mentioned lift-and-carry equipment, all the workpieces on the assembly line are placed on a pair of shuttle bars, and the shuttle bars are moved up and down or reciprocated by each drive device, so the drive device uses hydraulic pressure. There is a problem in that the equipment is large-scale and operates by various means, and the equipment cost increases. Moreover, when such a drive device is installed on the floor of an assembly line, the floor space available for assembly jigs, etc. becomes narrow, which poses the problem of interfering with the layout of each jig. ing.

On the other hand, conventionally, as a device for conveying workpieces in a pinch, a rail is provided along the conveyance direction on the ceiling above the assembly line, a hanger is movably suspended on the rail via a trolley, and the trolley is conveyed to each trolley. A transformer monorail type is known that is equipped with a drive device that reciprocates one pitch in the direction. When this transmonorail type pitch conveyance device is used for pitch conveyance of workpieces on the assembly line as described above, a lift device is provided at each assembly station, and as the lift device descends, the above-mentioned hanger The workpiece supported by the lift device is suspended and transported to the front assembly station, and as the lift device moves upward, the workpiece is cut off from the hanger and lifted and supported.

In this case, by using separate devices to carry the work piece and lift it up and down, it is possible to simplify the structure of the drive device and reduce equipment costs, and at the same time, because the drive device is not installed on the floor of the assembly line, space is increased. This allows the assembly jig to be placed in the optimal position. On the other hand, however, since the workpiece is suspended by a hanger, the hanger interferes with and obstructs the assembly jig that moves around the workpiece during assembly, impairing the ease of assembly.

(Object of the Invention) The object of the present invention is to use separate devices for pitch conveyance and lifting of workpieces in the above-mentioned assembly line, similar to the above-mentioned trans-monorail type pitch conveying device, but instead of the trans-monorail. The pitch transfer device is made of a trolley type, and the left and right workpieces are supported independently by running bodies installed on both sides of the lifting device, and only one of the running bodies moves by itself when moving forward. The structure has been made extremely simple to significantly reduce equipment costs and make effective use of floor space, while ensuring that workpieces can be conveyed in pitch without interfering with the lifting device, and eliminating interference during assembly. The objective is to improve the workability of assembling workpieces.

(Structure of the Invention) In order to achieve the above-mentioned object, the solution means of the present invention is to convey the work piece by piece to a plurality of assembly stations, lift and support the work piece with a lift device at each assembly station, and perform the assembly work. In the assembly line, rails are provided along the assembly line on the left and right sides of the lift device of each assembly station, and a plurality of wheel units each having a traveling roller and a work receiving jig are connected in series to each rail. one of the left and right running bodies is provided with a high-output first drive mechanism that drives the running rollers to rotate in the forward direction when moving forward, and drives the running rollers in the reverse direction when moving backward; is provided with a second drive mechanism with a small output that does not drive the running rollers when moving forward and drives the running rollers in reverse when moving backwards.

As a result, assembly at the assembly station can be carried out without interference with other parts while the workpiece is lifted and supported by the lift device, and when this assembly is completed, the lift device moves down and the wheels of the left and right traveling bodies are moved. After the workpiece is placed on the unit, one of the traveling bodies moves forward one pitch by the first drive mechanism, and the workpiece is transported to the front assembly station with support on one side by the other traveling body, and then the lift While the device moves upward to lift and support the workpiece, each of the traveling bodies is moved backward by one pitch and returned to its original position by the first drive mechanism and the second drive mechanism.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

The drawings show an embodiment in which the present invention is applied to pitch conveyance in an assembly line for welding the underbody of an automobile. FIG. 1 shows an assembly line L that extends linearly, and the assembly line L is provided with a plurality of (three locations in the figure) assembly stations S, S, etc. at predetermined pitch intervals, and each assembly station S
Welding machines R, R, . Also, on the assembly line L, a pitch conveying device P is provided in the arrangement direction of the assembly stations S.
In addition, each assembly station S is provided with a lift device T to lift the workpiece W.
are sequentially conveyed in pitches by the pitch conveying device P to the assembly station S located forward in the conveyance direction (in the direction of the arrow in the figure), while the workpieces W conveyed to each assembly station S are lifted and supported by the lift device T. , welding machines R, R... are configured to perform welding.

2 to 4 show the pitch conveyance device P, in which rails 1 and 2 extending in the conveyance direction are provided in parallel on the left and right sides of the lift device T of each assembly station S. A pair of wheel units 3, 4 are respectively disposed on each of the rails 1, 2 at the pitch interval.

As shown in FIGS. 5 and 6, each of the wheel units 3 and 4 includes a guide member 5 arranged on the side of the rail 1 or 2, and an upper part of the guide member 5.
a running roller 6 that is rotatably supported on the side and rolls on the rail 1 or 2; and a guide roller that is rotatably supported on the guide member 5 and that circumferentially contacts the side of the rail 1 or 2. 7, 7... (three pieces in the figure) and a receiving jig 8 provided on the upper part of the guide member 5 to receive one side (left side) of the workpiece W, and can be moved in the transport direction on the rail 1 or 2. The wheel units 3, 4, 3, 4... disposed on each of the rails 1 or 2 are connected in a straight line by pipe-shaped connecting rods 9, 9... Running bodies 10 and 11 are constructed. Of the pair of wheel units 3 and 4 of the traveling body 10 on the left side in the conveyance direction, the wheel unit 3 on the front side in the conveyance direction has its traveling roller 6 rotated in the forward direction when moving forward, and the traveling roller 6 when moving backward. An electric drive motor 12 that drives in reverse is provided, and the drive motors 12, 12... (first
The first drive mechanism 13 with high output (three in the figure)
is configured. On the other hand, among the wheel units 3 and 4 of any pair (middle one in FIG. 1) of the traveling body 11 on the right side in the conveyance direction, the wheel unit 3 on the front side in the conveyance direction has a traveling roller 6 when it moves forward.
A second electric drive mechanism 14 with a small output is provided which does not drive the traveling roller 6 and reversely drives the traveling roller 6 when retracting, and by driving the traveling body 10 forward with one pitch stroke, the work The left side of the vehicle is mounted on the receiving jigs 8 and 8 of the pair of wheel units 3 and 4 of the left traveling body 10, and the right side is mounted on the receiving jigs 8 of the pair of wheel units 3 and 4 of the right traveling body 11. .
is configured to drive backward even with a one-pitch stroke.

Note that the power supply cables 15 for each drive mechanism 13, 14 are arranged within the connecting rods 9, 9, . . . .

Next, to describe the operation of the above embodiment, the workpiece W is lifted and supported above the pitch transfer device P by the lift device T of each assembly station S (the dotted line position in FIGS. 2 and 4). , In this state, welding assembly is performed by the welding machine R at each assembly station S. When this assembly is completed, the lift device T moves downward, so that the workpiece W is placed on the wheel units 3 and 4 of the traveling bodies 10 and 11 and is supported on the left and right sides (see Figs. 2 and 4). imaginary line position in the figure).

Next, one of the traveling bodies 10 and 11 is driven forward by one pitch with high output, so that the workpiece W is transported to the assembly station S in front. At this time, since the traveling bodies 10 and 11 are provided independently on both sides of the lift device T, they do not interfere with the lift device T.

Next, as the lift device T moves upward, the workpiece W is lifted and supported by the lift device T, while both the traveling bodies 10 and 11 are driven backward one pitch to return to their original positions, and the above-mentioned operation is continued. By repeating this process, the workpieces W are sequentially conveyed in pitches and welded and assembled.

Therefore, since the workpiece W is raised and lowered by the lift device T and the workpiece W is conveyed in pitches by the pitch conveyance device P, the structure of the drive mechanisms 13 and 14 of the pitch conveyance device P can be simplified. Can be done. Moreover, the wheel units 3 and 4 are provided independently from each other on both sides of the lift device T, and each supports the left and right sides of the workpiece W, and the first drive mechanism 13
The second drive mechanism 14 has a large output that drives the left side traveling body 10 forward and backward, and the second drive mechanism 14 does not drive the right side traveling body 11 when the workpiece W is moving forward, and also has a light right side traveling mechanism that does not carry the workpiece W when reversing. Since a small output power is used to drive the body 11, there is no need for a large-scale drive device like the conventional lift-and-carry device, and the structure of the pitch transfer device P can be further simplified, reducing equipment costs. At the same time, it is possible to secure a large floor space that can be used for assembly jigs such as welding machine R.
It is possible to arrange each jig at an optimal position.

Further, since the workpiece W is carried on the independent wheel units 3 and 4 on both sides of the lift device T, the workpiece can be conveyed smoothly and reliably in pitches without interference with the lift device T. At the same time, there is no interference with the hanger as in the conventional transformer monorail type, and the welding machine R can be moved smoothly, thereby improving welding and assembly workability.

(Effects of the Invention) As described above, according to the present invention, a traveling body that lifts and lowers a workpiece with a lift device, and that is provided independently on both sides of the lift device and drives with high output during both forward and backward movement, and The workpiece is supported and transported between the left and right sides using a traveling body that is not driven when moving and is driven with a small output when reversing, eliminating the need for a large-scale drive device like the conventional lift-and-carry device. The structure of the transport device can be made extremely simple, and equipment costs can be reduced and floor space can be used effectively.
Moreover, since the workpiece is carried on independent wheel units on both sides of the lift device, it is possible to reliably carry the workpiece in pitch, and there is no interference with the hanger like in the conventional transmonorail type. Assembling workability can be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a plan view of an assembly line, FIG. 2 is a plan view of essential parts of a pitch conveying device, FIG. 3 is a side view of the same, and FIG. 5 is an enlarged view of the main part of FIG. 4, and FIG. 6 is a side view of the same. L... Assembly line, S... Assembly station,
W...Workpiece, P...Pitch transport device, T...Lift device, 1...Rail, 2...Rail, 3...
Wheel unit, 4... Wheel unit, 6... Running roller, 8... Receiving jig, 10... Running body, 11...
...running body, 13...first drive mechanism, 14...second
Drive mechanism.

Claims (1)

[Claims] 1. In an assembly line where workpieces are sequentially conveyed in pitch to multiple assembly stations, and at each assembly station the workpieces are lifted and supported by a lift device for assembly work, the left and right sides of the lift device of each assembly station are A rail is provided along the assembly line, and each rail has a plurality of wheel units each having a running roller and a workpiece receiving jig connected in series and arranged as a running body. One of the traveling bodies is provided with a high-output first drive mechanism that drives the traveling rollers in forward rotation when moving forward and reversely drives the traveling rollers when retreating, and the other traveling body is provided with a first drive mechanism that rotates the traveling rollers in forward rotation when moving backward. 1. A pitch conveyance device for workpieces in an assembly line, characterized in that it is not driven and is provided with a second drive mechanism with a small output that drives the traveling roller in the reverse direction when retracting.