JPH04275843A - Workpiece conveying device - Google Patents

Abstract

PURPOSE:To provide a workpiece conveying device which can quickly change line constitution according to the change of types of workpieces and is suitable to multi-kind small batch production and of high productivity. CONSTITUTION:In a workpiece conveying device with an upper conveyer 101 in the approach route, a lower conveyer 102 in the separation route and a plurality of machining stations 106 provided along the conveyer 101, an intermediate return unit 201 for moving a workpiece 17 between the conveyers 101 and 102 is provided at least one position between machining stations 106. A machined workpiece 17 is moved to a return conveyer through the intermediate return unit 201 without being conveyed to the unnecessary machining stations A=on the down stream side.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a workpiece conveyance device having a reciprocating conveyance path suitable for application to automatic assembly lines.

0002

BACKGROUND OF THE INVENTION In recent years, technological innovations have made electronic devices lighter, thinner, and smaller, and the demand for high-mix, low-volume production is increasing. For this reason, automatic assembly lines using general-purpose robots have come into widespread use.

This automatic assembly line has conventionally been constructed as shown in FIG. 8, for example. That is, an upper stage conveyor 101 serving as a first conveyance path is provided at the upper stage to convey the workpiece.
A lower stage conveyor 102, which is a second conveyance path, is provided in the lower stage in parallel with each other. At one end of both conveyors 101 and 102, there is a stocker 103 for storing parts and assemblies, respectively.
104 is provided, and a return unit 105, which is a moving means for moving the work from the upper conveyor 101 to the lower conveyor 102, is provided at the other end. Also, along the upper conveyor 101, a plurality of processing stations 106 having robots that perform processing including assembly of workpieces are installed at predetermined intervals.

[0004] With the work conveyance device configured as described above, the work is taken out from the stocker 103 and placed on a pallet (not shown), and is conveyed by the upper stage conveyor 101 and processed in each step at the processing station 106. The processed work is returned to the return unit 10.
5 is moved onto the lower conveyor 102, conveyed in the opposite direction to the upper conveyor 101, and stored in the stocker 104.

[0005]

However, as high-mix low-volume production progresses, machining may not necessarily be completed without using all of the machining stations 106, depending on the type of workpiece. In such a case, in order to return the workpiece to the stocker 104, the workpiece is conveyed the entire length of the upper conveyor 101, passes through the return unit 105, is conveyed the entire length of the lower conveyor 102 again, and is returned to the stocker 104. There was a problem in that the transfer efficiency was lowered because the paper was sent to an unnecessary processing station 106. Furthermore, since the workpieces are present over the entire length of the conveyors 101 and 102, the conveyance density becomes unnecessarily large, which has the disadvantage of hindering the improvement of production volume.

The present invention has been made in view of the above circumstances, and provides a workpiece conveyance device suitable for high-mix, low-volume production, which can quickly change the line configuration and improve productivity. The purpose is to provide.

[0007]

Means for Solving the Problems A workpiece conveyance device according to claim 1 includes a first conveyance path for conveying a workpiece in one direction, and a first conveyance path provided in parallel below the first conveyance path. A workpiece conveyance device having a second conveyance path for conveying the workpiece in a direction opposite to the conveyance path, and a plurality of processing stations provided at predetermined positions along the first conveyance path. The present invention is characterized in that a moving means for moving the workpiece on one of the pair of transport paths to the other transport path is provided at at least one location between the stations.

[0008] The workpiece conveyance device according to the second aspect of the present invention includes a moving unit that carries a workpiece and moves up and down between a pair of conveyance paths, and a second conveyance path in a lowered position of the movable unit. a fixed unit that is provided and that transports the work on a second transport path; a transport means that transports the work placed on the movable unit and the fixed unit; and a drive means that drives the movable unit up and down. It is characterized by

[0009]

[Operation] In the workpiece conveying device configured as claimed in claim 1,
By activating the moving means closest to the downstream side of the last processing station that requires processing among the plurality of processing stations, the processed workpiece can be moved onto the return conveyance path. Therefore, unnecessary transport of workpieces to processing stations can be eliminated, congestion of workpieces on the transport path can be minimized, and a decrease in production can be prevented.

[0010] In the workpiece conveyance device having the structure of claim 2, when the workpiece being conveyed on one of the conveyance paths is placed on the movable unit, the movable unit does not move up and down unless the workpiece is returned; The workpiece is transported as it is in the same direction by a transport means provided on a movable unit or a fixed unit. When returning the movable unit, the conveyance means for the movable unit is stopped, and the movable unit is driven up and down by the moving means so that it is at approximately the same height as the other conveyance path. Thereafter, the workpiece is transported in the opposite direction by a transport means provided on the fixed unit or the movable unit. Furthermore, when the movable unit is on the upper first conveyance path side, the fixed unit acts as the second conveyance path.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a workpiece conveying apparatus according to the present invention will be described below with reference to the drawings. 1 to 5 show the configuration of an embodiment of the present invention. In these figures, parts corresponding to those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and explanations thereof will be omitted as appropriate. In FIG. 1, when the processing stations on the most downstream side of conveyors 101 and 102 are respectively 106C and 106A, intermediate return units 201A and 2 which are moving means between processing stations 106A and 106B and between 106B and 106C, respectively.
01B is provided.

FIGS. 2 to 5 show an intermediate return unit 20.
1 (201A, 201B) is shown. In the figure,
Upper conveyor 10 between adjacent processing stations 106
1 and the lower conveyor 102 are partially cut off at positions where they match in the vertical direction. At this cut portion of the lower conveyor 102, a fixing unit 1 is provided fixed to the substrate 3 via a pedestal 2.

The fixing unit 1 is formed into a substantially rectangular plate shape, and two opposing sides parallel to the conveyance direction are bent upward at right angles, and a support portion 4 for supporting a pallet, which will be described later, is formed.
(Figure 3). In addition, each of the pair of support parts 4 has a plurality of, for example, four
rollers 5 are provided. One roller 6, 7 is rotatably supported on a vertical support shaft on each side of the upper surface of the fixed unit 1 at the center with respect to the conveyance direction (
Figure 4). As shown in FIG. 5, an endless belt 8 is wound around these rollers 5, 6, and 7. Further, a first motor 9, which is a conveyance means having a vertical drive shaft, is attached to the lower surface of the fixed unit 1. The first motor 9 rotates a roller 6, and an endless belt 8 having a circular cross section is attached. It is designed to drive. Furthermore, a pair of first sensors 10 are provided at approximately the center of the fixed unit 1 in the width direction (vertical direction in FIG. 4) and at both ends in the transport direction, each detecting and positioning a transported pallet. There is.

On one side of the conveyors 101 and 102 at the position where the fixed unit 1 is provided, a rodless cylinder 11 serving as a driving means is fixed vertically, and a movable unit is attached to the sliding portion 12 of the rodless cylinder 11. 13 are installed horizontally. The movable unit 13 is formed in the shape of a rectangular frame, and a plurality of rollers 14, for example, four rollers 14, each rotatably supported on a horizontal support shaft, are provided on two opposing sides in the conveyance direction. Figure 2
). Further, an endless belt 15 having a circular cross section is stretched around the roller 14, and one end of the roller 14 is attached to a movable unit 13.
It is rotatably driven by a second motor 16 which is attached to and has a horizontal drive shaft. Both sides of the pallet 18 in the width direction (left and right direction in FIG. 3) on which the workpiece 17 is placed are guided by the inner surface of the movable unit 13 in the conveying direction, and an endless roller driven by the second motor 16 via the roller 14 It is conveyed by a belt 15 (in a direction perpendicular to the plane of the paper in FIG. 3). Furthermore, a pair of second sensors 19 are provided at both ends of one side surface (upper side surface in FIG. 4) of the movable unit 13 for detecting and positioning the pallet 18 that has been transported.

When the movable unit 13 attached to the slide portion 12 is lowered by the rodless cylinder 11, it enters the outside of the fixed unit 1 as shown in FIG. belt 1
5 is the outside of the endless belt 8 on the inside (fixed unit 1),
Moreover, it is located slightly below the endless belt 8. Grooves 20 (FIG. 3) are formed in the vicinity of both ends of the lower surface of the pallet 18 in parallel to the conveying direction, and the support portion 4 of the fixing unit 1 fits into and abuts within the grooves 20 at the lower end of the pallet 18. Positioned. In this state, the pallet 18 is conveyed by the endless belt 8 on the fixed unit 1 side.

[0016] Also, the upper stage conveyor 101 and the lower stage conveyor 1
Sensors 21 and 22, which are identification means, are provided upstream of the intermediate return unit 201 of 02 (FIG. 2). The sensors 21 and 22 read an ID card (not shown) attached to the bottom surface of the pallet 18 to identify the type of workpiece 17 on the pallet 18. Then, based on the signals identified by the sensors 21 and 22, the rodless cylinder 11 and the motor 9 are
, 16.

Next, the operation of this embodiment will be explained with reference to FIGS. 6 and 7. In Figure 6, the work 17 is transferred to the upper conveyor 101.
The case is shown in which the image is moved from to the lower conveyor 102. In (a), the workpiece 17 is being conveyed on the upper stage conveyor 101 in the direction indicated by arrow A. At this time, an ID card is affixed to the lower surface of the pallet 18 in which the number of the processing station 201 that requires processing determined by the type of the workpiece 17 is stored. When the sensor 21 reads this ID card and there is a processing station 201 that requires processing remaining on the downstream side, the rodless cylinder 11 does not operate and the movable unit 13 moves to the upper stage conveyor 10.
It is on the same level as 1. Then, the second motor 16 on the movable unit 13 side is driven to rotate the endless belt 15 and convey the work 17 as it is to the upper conveyor 101 on the downstream side (see FIG. 2).

When the sensor 21 reads the ID card and identifies that there is no machining station 201 remaining downstream that requires machining, the work 17 is conveyed onto the movable unit 13 and the sensor 19 detects the work 17. When it is detected that the motor 16 of the movable unit 13 has reached a predetermined position, the rotation of the motor 16 of the movable unit 13 is stopped. In this embodiment, two sensors 19 are provided in the transport direction, and by calculating the AND of both outputs, accurate position detection is possible. Next, when the sensor 10 detects that no other pallet is placed on the fixed unit 1, the rodless cylinder 11 is actuated to move the movable unit 13 as shown by arrow B in FIG. 6(b). Descending. At this time, since the belt 15 of the movable unit 13 is located slightly below the belt 8 of the fixed unit 1, the pallet 18 is transferred onto the fixed unit 1. Moreover, at this time, the pallet 18 is positioned and supported by the support part 4,
It is placed on the endless belt 8 (see FIG. 3). In this state, the first motor 9 on the fixed unit 1 side starts rotating, and the workpiece 17 is conveyed along with the pallet 18 to the downstream side of the lower conveyor 102 as shown by arrow C in FIG. 6(c). When the conveyance (feeding) is completed, the rotation of the first motor 9 is stopped, and the movable unit 13 is raised by the rodless cylinder 11 and returns to the original position shown in FIG. 6(a).

FIG. 7 shows the case where the work 17 is moved from the lower conveyor 102 to the upper conveyor 101. In this case as well, the operation is almost the same as that described above, and the lower conveyor 10
A sensor 22 identifies whether or not the work 17 conveyed on the top of the workpiece 2 should be returned. If the workpiece 17 is not to be returned, the first motor 9 is driven to allow the workpiece 17 to pass over the fixed unit 1 as it is. If you want to return, please refer to Figure 7 (a)
), (b), the rodless cylinder 11 is operated to lower the movable unit 13 in the direction shown by arrow B. At this time, the second motor 16 (therefore, the belt 15
) rotation is stopped. After the fixed unit 1 enters the frame of the movable unit 13, the second motor 16
The workpiece 17 starts rotating in the opposite direction from when it is positioned on the upper conveyor 101, and moves the workpiece 17 in the direction shown by arrow C, as shown in FIG.
As shown in (c), after the workpiece 17 is placed at a predetermined position on the fixed unit 1, the rotation of the second motor 16 is stopped. This position is accurately detected by calculating the AND of the outputs of the two sensors 10. Next, the rodless cylinder 11 is operated to raise the movable unit 13 in the direction shown by arrow D, and the movable unit 13 is brought to the same level as the upper stage conveyor 101 as shown in FIG. 7(d). Then, the second motor 16 is rotated in the opposite direction to that on the lower conveyor 102 to move the workpiece 17 in the direction shown by arrow E and convey it onto the upper conveyor 101.

Upper conveyor 101 and lower conveyor 102
In a normal state in which there is no transfer of workpieces 17 between 17 is transported in the normal direction.

[0021] Furthermore, the rodless cylinder 11 and the motor 9
, 16 are controlled by a control circuit 40 based on signals from sensors 10, 19, 21, 22.

According to the workpiece conveying apparatus according to this embodiment configured as described above, for example, the workpiece 17A shown in FIG.
needs to be processed only by the processing station 106B, and the workpiece 17B is processed by the processing stations 106B and 106.
When processing by C is required, the workpiece 17A is moved from the upper conveyor 101 to the lower conveyor 102 by the intermediate return unit 201B. Then, it is returned to the stocker 104 shown in FIG. 8 by the lower conveyor 102. In other words, processing station 106C where processing is not performed.
Since the workpiece 17A is not conveyed to the conveyor 101,
The conveyance length of the workpiece 17A on the workpiece 102 can be shortened, and congestion of the workpiece 17 can be minimized. As a result, productivity of the production line can be improved.

After the workpiece 17B has been processed by the final processing station 106C, it is sent onto the lower conveyor 102 via the return unit 105 as in the conventional example, and is transported in the opposite direction to the stocker 104.

[0024] In this way, even if the type of workpiece 17 changes, there is no need to change the line configuration, and it is only necessary to change the ID card affixed to the pallet 18, making it possible to quickly change the line configuration. . Therefore, it is possible to realize a conveying device suitable for high-mix, low-volume production.

[0025] In the above embodiment, an ID card is used as the identification means, but it is also possible to use something other than an ID card, such as a bar code. Further, the number and arrangement of the processing stations 106 and intermediate return units 201 shown in the above embodiments are merely examples, and the present invention is not limited thereto.

[0026]

As explained above, according to the workpiece conveyance device according to claim 1, since the moving means for moving the workpiece located on one of the upper and lower conveyance paths to the other is provided between the processing stations, the workpiece Even if the type of material changes, the line configuration can be quickly changed, making it possible to realize a conveying device suitable for high-mix, low-volume production. Moreover, congestion of workpieces on the conveyance path can be minimized, and productivity of the production line can be improved.

Further, according to the workpiece conveying device according to the second aspect, since the moving means is constituted by the fixed unit and the moving unit, the workpiece can be moved without being held up.
It can be transported not only in the normal direction but also in other directions.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of an embodiment of a workpiece conveyance device of the present invention.

FIG. 2 is a front view showing the configuration of the intermediate return unit of the embodiment of FIG. 1;

FIG. 3 is a side view of the embodiment of FIG. 2;

FIG. 4 is a plan view of the embodiment of FIG. 2;

FIG. 5 is an explanatory diagram showing the arrangement of the endless belt in the embodiment of FIG. 4;

FIG. 6 is an explanatory diagram illustrating an operation of moving a workpiece from an upper conveyor to a lower conveyor according to the present embodiment.

FIG. 7 is an explanatory diagram illustrating an operation of moving a workpiece from a lower conveyor to an upper conveyor according to the present embodiment.

FIG. 8 is an explanatory diagram showing the configuration of an example of a conventional work transfer device.

[Explanation of symbols]

1 Fixed unit 9 First motor (transporting means) 11 Rodless cylinder (driving means) 13 Movable unit 16 Second motor (transporting means) 17 Workpieces 21, 22 Sensors (identification means) 101 Upper conveyor (first transporting means) (path) 102 Lower conveyor (second conveyance path) 106 Processing station

Claims (2)

[Claims] 1. A first conveyance path that conveys a workpiece in one direction; and a second conveyance path that is provided below and parallel to the first conveyance path and that conveys the workpiece in a direction opposite to the first conveyance path. In the workpiece conveyance device having a conveyance path of 1 and a plurality of processing stations provided at predetermined positions along the first conveyance path, at least one part of the pair of conveyance paths is provided between the processing stations. A workpiece conveyance device comprising a moving means for moving the workpiece on one of the conveyance paths onto the other conveyance path. 2. The moving means is provided in a movable unit on which the work is placed and moves up and down between a pair of conveyance paths, and a second conveyance path in a lowered position of the movable unit,
A fixed unit that transports the work on the second transport path, a transport means that transports the work placed on the movable unit and the fixed unit, and a drive means that drives the movable unit up and down. The workpiece conveyance device according to claim 1, characterized in that: