US20020009354A1

US20020009354A1 - Cable assembler

Info

Publication number: US20020009354A1
Application number: US09/875,725
Authority: US
Inventors: Akihiro Nagaya; Yasushi Nishi; Morishisa Ishizawa
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2000-06-06
Filing date: 2001-06-05
Publication date: 2002-01-24
Also published as: JP2001347428A

Abstract

A cable assembler which makes it possible to carry out in a short tact time the assembling of cable terminal which needs a plurality of jigs and tools. A robot delivers a bobbin of cable to various stations in a working area. Processing in accordance with the invention reduces tact time.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is related to and claims priority from Japanese Patent Application No. 2000-168444, filed on Jun. 6, 2000.

BACKGROUND OF THE INVENTION

The present invention relates to a cable assembler, and more particularly, to a cable assembler suitable for the terminal finishing of optical cable.

The conventional automatic assembler by a robot usually operates in such a way that the work is fixed on a previously arranged assembling line and the robot does assembling according to the previous established procedure. An example of such conventional automatic assemblers is disclosed in Japanese Patent Laid-open No. 320363/1994. It consists of several robots arranged back to back on one station of a previously installed line. The robots move and rotate to do complicated assembling operations.

Unfortunately, the assembling system disclosed in Japanese Patent Laid-open No. 320363/1994 has the disadvantage of requiring many robots and many stations on the line for the process, such as the terminal finishing of optical cable, which needs a plurality of complex tools and jigs. This leads to a long period and a large expense for development. The disadvantage of this system is that the tact time becomes longer because the number of steps to be carried out in one station increases.

There is a need to provide a cable assembler which is capable of the terminal finishing of cable in a short tact time even though the terminal finishing requires a plurality of jigs and tools.

SUMMARY OF THE INVENTION

The first aspect of the present invention resides in a cable assembler of the type having a robot which holds and moves the work by a mechanical hand attached to the forward end thereof and a plurality of processing means arranged within the working area of the robot, said robot moves the work sequentially from one processing means to another for the execution of individual processing, wherein said robot transfers works such that one work undergoes one processing while the other work undergoes another processing which takes a longer time among a plurality of processing steps.

This constitution reduces tact time because the work is transferred to the step which takes a long processing time while the other work is being processed by other processing means.

The second aspect of the present invention resides in the cable assembler as defined the first aspect above, wherein the processing means to receive said work consists of a plurality of processing means having identical functions and said robot transfers the work to the processing means which is idle among the plurality of processing means.

This constitution reduces tact time further owing to parallel operation by a plurality of processing means having identical functions.

The third aspect of the present invention resides in the cable assembler as defined in the first aspect above, wherein said mechanical hand is provided with a chuck which has the mechanism to hold the work and change the direction of the held work.

This constitution simplifies the construction of the processing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing the layout of the entire structure of the cable assembler according to an illustrative embodiment of the present invention; [0012]
FIG. 2 is a fragmentary sectional view showing the structure of the terminal of the optical cable which has undergone terminal processing by the cable processing apparatus according to an illustrative embodiment of the present invention; [0013]
FIG. 3 is a perspective view showing the structure of a mechanical hand used for the pre-finishing station of the cable assembler shown in FIG. 1, according to an illustrative embodiment of the present invention; [0014]
FIGS. [0015] 4(A)-4(G) show the steps which are carried out by the pre-finishing station of the cable assembler shown in FIG. 1, according to an illustrative embodiment of the present invention;
FIG. 5(A) is a perspective view of the mechanical hand used for the post-finishing station of the cable assembler shown in FIG. 1, according to an illustrative embodiment of the present invention; [0016]
FIG. 5(B) is an expanded view of the circled portion of the mechanical hand shown in FIG. 5(A); [0017]
FIGS. [0018] 6(A)-6(E) are perspective views showing the actions of the connector inserter used for the post-finishing station of the cable assembler shown in FIG. 1, according to an illustrative embodiment of the present invention; and
FIG. 7 is a diagram showing the processing which occurs in the post-finishing station of the cable assembler shown in FIG. 1, according to an illustrative embodiment of the present invention.[0019]

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The invention will be described with reference to FIGS. [0020] 1 to 7 which illustrate the construction and mechanism of a cable assembler merely as an example of an embodiment of the present invention. In particular, the following explanation is made in reference to a cable assembler that handles optical fiber of twin-core type for its terminal finishing.
First, the entire construction of the cable assembler according to the present invention is explained below with reference to FIG. 1. FIG. 1 is a plan view showing the layout of the cable assembler according to the present invention. [0021]
The cable assembler according to the present invention comprises a [0022] pre-finishing station 10 and a post-finishing station 30. The pre-finishing station 10 includes a horizontal articulated robot 11 having a mechanical hand 20 at its forward end. Within the working area of the horizontal articulated robot 11 are arranged a plurality of workstations including an outer coat stripper 13, a sleeve inserter 14, and a crimper 15.
A detailed description of the [0023] components 13, 14, and 15 will be given later with reference to FIG. 3. An outline is given here.
A loader-[0024] unloader 12 receives a cable bobbin 60 (as a work) which is manually placed thereon. The bobbin 60 has an optical fiber cable 50 wound thereon. From the bobbin 60, protrude both ends of the cable (designated by 50A and 50B) which are to undergo terminal finishing.
The horizontal articulated [0025] robot 11 has joints J1 and J2. The robot 11 rotates about a center J0. The portion of the robot between the center 10 and the joint J1 rotates in the direction of arrow A1. The portion of the robot between the joint J1 and the joint J2 rotates in the direction of arrow A2. To the forward end of the joint J2 is attached a mechanical hand 20, which rotates in the direction of arrow A3. In addition, the center of the robot 11 is movable in the vertical direction (i.e., in a direction above and below the plane of the paper). Consequently, the mechanical hand 20 attached to the forward end of the horizontal articulated robot 11 is movable in three-dimensions.
The outer coat stripper [0026] 13 cuts and removes the outer coat of the each end 50A, 50B of the optical fiber 50 and then cuts the Kevlar. The sleeve inserter 14 inserts the end of the optical fiber 50 into the strain relief. The crimper 15 slips a crimping ring on the end of the optical fiber 50 and then crimps the crimping ring.
A detailed description of the [0027] mechanical hand 20 will be given later with reference to FIG. 3. The mechanical hand 20 loads the work 60 from the loader-unloader 12, and moves it to the outer coat stripper 13 which cuts the outer coat. Then, the mechanical hand 20 moves the work 60 to the sleeve inserter 14 which inserts a strain relief. Then, the mechanical hand 20 moves the work 60 to the crimper 15 which crimps the crimping ring. When the crimping step is completed, the mechanical hand 20 unloads the work 60 back to the loader-unloader 12.
The [0028] post-finishing station 30 constitutes a cable work area having a horizontal articulated robot 31 which has a mechanical hand 40 at its forward end. Within a first area in the working area of the horizontal articulated robot 31 are arranged a plurality of workstations including a loader station 32, an inner coat stripper 33, and a connector part inserter 34. A second area in the working area includes an adhesive setter 35. A third area in the working area includes another plurality of workstations, including a grinder 36, a polisher 37, and an unloader 38. The adhesive setter 35 comprises a plurality of identical curing ovens, first through third ovens 35A, 35B, and 35C.
A detailed description of what the [0029] components 33 to 37 do will be given later with reference to FIG. 4. An outline is given here.
The [0030] loader station 32 receives from the loader-unloader 12 a cable bobbin 60 that has undergone the pre-finishing step discussed above. The cable bobbin is manually transferred from the loader-unloader to the loader station 32.
The horizontal articulated [0031] robot 31 has joints J1 and J2. The robot 31 rotates about a center J0. The part between the center J0 and the joint J1 rotates in the direction of arrow B1. The part between the joint J1 and the joint J2 rotates in the direction of arrow B2. To the forward end of the joint J2 is attached a mechanical hand 40, which rotates in the direction of arrow B3. The center J0 of the robot 31 is movable in the vertical direction (i.e., in a direction above and below the plane of the paper). In other words, the mechanical hand 40 attached to the forward end of the horizontal articulated robot 31 is movable in three-dimensions.
The [0032] robot 31 is controlled by a controller 31CONT. The controller 31CONT communicates via communication lines 31COMM with the inner coat stripper 33, the connector part inserter 34, the adhesive setter 35, the grinder 36, and the polisher 37 through communications circuits. The controller receives signal from the devices indicating the completion of operation from each device.
The [0033] inner coat stripper 33 strips the inner coat of the optical cable 50 and removes the primary coat. The connector part inserter 34 inserts connector parts (to which an adhesive has been applied) into the end of the optical cable 50. The adhesive setter 35 heats and cures the adhesive. The grinder 36 removes the adhesive and the core protruding from the end of the connector part. The polisher 37 polishes the end surface of the connector part.
After terminal finishing according to the present invention, the end of the optical cable has a structure as shown in FIG. 2. [0034]
FIG. 2 is a sectional view showing the structure of the end of the optical cable which has undergone terminal finishing by the cable assembler according to the present invention. FIG. 2 shows the optical fiber, with its inner coat stripped off by the [0035] inner coat stripper 33.
The [0036] optical cable 50 comprises two cores 51. Each core is covered with a primary coat 52A. Disposed over the primary coat is an inner coat 52. The two cores are covered with an outer coat 54. Between the inner coat 52 and the outer coat 54 is interposed the Kevlar 53. The core 51 is 0.2 mm in diameter, for example. The outer coat 52 is made of Teflon and 2 mm in diameter, for example. The Kevlar 53 is a long plastic string comprised of thousands of fibers interposed between the outer coat 54 and the inner coat 52. The Kevlar 53 protects the core 51. The outer coat 54 is made of polyvinyl chloride and is 10 mm in outside diameter, for example.
With the end of the [0037] inner coat 52 cut and removed, the core 51 is exposed. At the end of the optical cable 50, a sleeve Sv is inserted between the Kevlar 53 and the inner coat 52. The sleeve Sv is made of polyvinyl chloride, for example. The end of the outer coat 54 is covered with a strain relief Sr. The strain relief Sr is made of polyvinyl chloride, for example. It relives the stress which the optical fiber 50 receives when it is bent. To the end of the strain relief Sr is fitted an inner crimp ring Ir, which is made of brass, for example. The inner crimp ring Ir has a knurled outer surface. The crimping ring Pr is slipped on the Kevlar 53 which has been folded back. The inner crimp ring Ir (between the strain relief Sr and the crimping ring Pr) is fixed to the Kevlar 53 by application of pressure from outside. The crimping ring Pr is made of copper, for example.
What occurs in the [0038] pre-finishing station 10 of the cable assembler of the present invention is explained with reference to FIGS. 1 to 4.
First, an explanation is made below with reference to FIG. 3 of the [0039] mechanical hand 20 used in the pre-finishing station 10 of the cable assembler of the present invention.
FIG. 3 is a perspective view showing the construction of the [0040] mechanical hand 20 used in the pre-finishing station 10 of the cable assembler as one embodiment of the present invention.
The [0041] mechanical hand 20 has a cable bobbin chuck 22 comprising arms 22A and 22B. The arms 22A and 22B swing (to open and close) respectively in the direction of arrows C1 and C2 around the support on the base 21 of the mechanical hand 20. With the cable bobbin chuck 22 opened, the bobbin 60 (as the work) is set. As the cable bobbin chuck 22 is closed, the bobbin 60 is clamped by the chuck and held.
The [0042] base 21 has forward chucks 23A and 23B and forward chucks 24A and 24B. The forward chuck 23A is movable in the direction of arrow C3, and the forward chuck 23B is movable in the direction of arrow C4. The forward chucks 23A and 23B are moved in such a direction that their separation distance increases. While the forward chucks 23A and 23B are apart, an end of the optical fiber 50A is arranged. Then, the forward chucks 23A and 23B are moved in such a direction that their separation distance decreases. In this way the end of the optical cable 50A is held.
Similarly, the [0043] forward chuck 24A is movable in the direction of arrow C5, and the forward chuck 24B is movable in the direction of arrow C6. The forward chucks 24A and 24B are moved in such a direction that their separation distance increases. While the forward chucks 24A and 24B are apart, another end of the optical fiber 50B is arranged. Then, the forward chucks 24A and 24B are moved in such a direction that their separation distance decreases. In this way the end of the optical cable 50B is held.
What is done by the pre-finishing step is explained with reference to FIGS. [0044] 4(A)-4(G) and FIG. 1.
FIGS. [0045] 4(A)-4(G) show the steps carried out in the pre-finishing station 10 of the cable assembler as one embodiment of the present invention.
First, the horizontal articulated [0046] robot 11 moves to the position of the loader-unloader 12. The mechanical hand 20 attached to the forward end of the horizontal articulated robot 11 grips the bobbin 60 that had been previously manually loaded on the loader-unloader 12.
The horizontal articulated [0047] robot 11 inserts an end 50A of the optical cable 50 (which is held by the mechanical hand 20) into the outer coat stripper 13. As shown in FIG. 4(A), the outer coat stripper 13 cuts and removes the outer coat 54 at the end of the optical fiber 50, and it also cuts the Kevlar 53.
When the removal of the [0048] outer coat 54 and the cutting of the Kevlar 53 are completed, the horizontal articulated robot 11 moves the ends of the optical cable 50 (held in place by the mechanical hand 20) to the sleeve inserter 14. As shown in FIG. 4(A), the sleeve inserter 14 slips the strain relief Sr on the end of the optical fiber 50. It further slips the inner crimp ring Ir on the end of the strain relief Sr. As shown in FIG. 4(B), the sleeve inserter 14 further slips the sleeve Sv on the part between the Kevlar 53 and the inner coat 52. After the sleeve Sv has been slipped on, the sleeve inserter 14 moves the strain relief Sr toward the end of the optical cable such that the Kevlar 53 and the outer coat 54 are held between the sleeve Sv and the strain relief Sr.
After the sleeve Sv has been slipped on, the horizontal articulated [0049] robot 11 moves the ends of the optical cable 50 to the crimper 15. The crimper 15 folds back the end of the Kevlar 53, as shown in FIG. 4(C). Further, the crimper 15 slips the crimping ring Pr on the end of the optical fiber 50, as shown in FIG. 4(D), and then applies pressure to the periphery of the crimping ring Pr so as to deform and crimp the crimping ring Pr.
When the slipping on of the crimping ring Pr is completed, the horizontal articulated [0050] robot 11 transfers the bobbin 60 to the position of the loader-unloader 12 and then unloads the bobbin 60.
With the [0051] bobbin 60 placed on the loader-unloader 12, the washer spring Ws is slipped on the periphery of the inner coat 52, as shown in FIG. 4(E). This step is carried out manually rather than mechanically because manual operation is more efficient. To complete the previous crimping step, the washer spring is slipped on within the tact time, and the work (bobbin 60) is set on the loader station 32. In one embodiment of the invention, the work is manually transferred from the loader-unloader 12 to the loader station 32.
What is done by the [0052] post-finishing station 30 of the cable assembler will be described with reference to FIGS. 5, 6, 1, and 4.
First, an explanation is made below with reference to FIGS. [0053] 5(A) and 5(B) of the construction of the mechanical hand 40 used in the post-finishing station 30 of the cable assembler in one embodiment of the present invention.
FIG. 5(A) is a perspective view showing the [0054] mechanical hand 40 used in the post-finishing station 30 of the cable assembler in one embodiment of the present invention. FIG. 5(B) is an enlarged view of the circled portion of the mechanical hand shown in FIG. 5(A).
A [0055] cable bobbin chuck 42 of the mechanical hand 40 opens and closes in the directions of arrows D1 and D2, moving around the support of the mechanical hand 40 on the base 41. With the cable chuck bobbin 42 opened, the bobbin 60 (as the work) is set, and the cable chuck bobbin 42 is closed so as to hold the bobbin 60.
On the [0056] base 41 are mounted the outer coat chucks 43A and 43B and the outer coat chucks 44A and 44B. The outer coat chuck 43A is movable in the direction of arrow D3, and the outer coat chuck 43B is movable in the direction of arrow D4. The outer coat chucks 43A and 43B move in such a direction that their separation distance increases. While they are apart, one end 50A of the optical cable 50 is arranged. Then, the outer coat chucks 43A and 43B move in such a direction that their separation distance decreases. In this way the chuck grips onto the outer coat 54 of the end of the optical cable 50A. Also, the outer coat chuck 44A is movable in the direction of arrow D5, and the outer coat chuck 44B is movable in the direction of arrow D6. The outer coat chucks 44A and 44B move in such a direction that their separation distance increases. While they are apart, the other end of the optical cable 50 is arranged. Then, the outer coat chucks 44A and 44B move in such a direction that their separation distance decreases. In this way the outer coat 54 of the other end 50B of the optical cable 50 is held.
To the forward end of the [0057] outer coat chuck 43A is attached the end chuck 45A. The end chuck 45A holds the inner coat 52 of one of the two cores 51 at one end 50A of the twin-core optical fiber 50. To the forward end of the outer coat chuck 43B is attached the end chuck 45B. The end chuck 45B holds the inner coat 52 of the other of the two cores 51 at one end 50A of the twin-core optical fiber 50.
To the forward end of the [0058] outer coat chuck 44A is attached the end chuck 46A. The end chuck 46A holds the inner coat 52 of one of the two cores 51 at one end 50B of the twin-core optical fiber 50. To the forward end of the outer coat chuck 44B is attached the end chuck 46B. The end chuck 46B holds the inner coat 52 of the other of the two cores 51 at one end 50B of the twin-core optical fiber 50.
Referring to FIGS. [0059] 5(A) and 5(B), the end chucks 45A, 45B, 46A, and 46B are movable in the direction of arrow E. The end chucks 45A, 45B, 46A, and 46B are rotatable upward through 90° (from a neutral position A) in the direction of arrow E1 to and upward position A+. Hence the end chucks can direct the core 51 upward (vertically). The end chucks can also fix the core 51 at any angle between horizontal (neutral position A) and the upward vertical position A+.
Moreover, the end chucks [0060] 45A, 45B, 46A, and 46B are rotatable downward through 90° (from the neutral position A) in the direction of arrow E2, as shown in FIG. 5(B) to a downward vertical position A−. Hence the end chucks can direct the core 51 downward (vertically). The end chucks can also fix the core 51 at any angle between neutral position A and vertical downward position A−.
In other words, the end chucks [0061] 45A, 45B, 46A, and 46B of the mechanical hand 40 can move independently in the directions of E1 and E2 and change the direction of the cable end and hold it at a desired angle. The mechanical hand 40 changes the direction of the cable end in alignment with the setting direction of the stations. Therefore, it simplifies the construction of the single-function automatic machine.
The pre-finishing step will be explained with reference to FIGS. [0062] 4(A)-4(G) and 1.
First, the horizontal articulated [0063] robot 31 moves to the position of the loader-unloader 32. To the forward end of the horizontal articulated robot 31 is attached the mechanical hand 40. The mechanical hand 40 grips for loading the bobbin 60 placed on the loader-unloader 32. As explained with reference to FIGS. 5(A) and 5(B), the outer coat chucks 43A and 43B and the outer coat chucks 44A and 44B of the mechanical hand 40 hold both ends of the optical fiber 50, and the end chucks 45A, 45B, 46A, and 46B hold the inner coat 52 corresponding to the respective cores.
Then the horizontal articulated [0064] robot 31 inserts the end of the optical cable 50 (which is held by the mechanical hand 40) into the inner coat stripper 33. At this time, the end chucks 45A, 45B, 46A, and 46B insert it into the inner coat stripper 33, with the optical cable held such that the inner coat 52 is horizontal (neutral position A), as shown in FIG. 5(B).
The [0065] inner coat stripper 33 strips the end part of the inner coat of the optical cable 50. FIG. 4(D) shows the cable before stripping, and FIG. 4(E) shows the cable after stripping. Then, the inner coat stripper 33 removes the inner coat covering the periphery of the core 51. The inner coat may be silicone rubber, for example.
Next, the horizontal articulated [0066] robot 31 moves the end of the optical cable 50 (which is held by the mechanical hand) to the connector part inserter 34. At this time, the end chucks 45A, 45B, 46A, and 46B rotate through 90° in the direction of arrow E1, as shown in FIG. 5(B), and move to the connector part inserter 34 while holding the optical cable such that the inner coat 52 points upward. The connector part inserter 34 slips the connector part Cp (which is filled with an adhesive) on the end of the optical cable 50, as shown in FIG. 4(F).
What is done by the connector part inserter [0067] 34 (which is used in the post-finishing station 30 of the cable assembler) is explained below with reference to FIGS. 6(A)-6(E).
FIGS. [0068] 6(A)-6(E) are perspective views illustrating the operation of the connector part inserter 34 in the post-finishing station 30 of the cable assembler.
In this embodiment, the [0069] connector part inserter 34 communicates with the controller 31CONT of the robot 31 through the communication port, as explained above with reference to FIG. 1. Owing to communications between them, the controller 31CONT of the robot 31 helps the operation of the connector part inserter 34.
The controller [0070] 31CONT of the robot 31 starts communications with the connector part inserter 34 to make sure that the connector part inserter 34 is ready to work. Then, the controller 31CONT of the robot 31 issues an operation start command to the connector part inserter 34. At the same time, the mechanical hand 41 moves in the direction of arrow F1 while holding the cores of the optical cables 50A and 50B upward, and transfers them to the stationary core guide 34A of the connector part inserter 34, as shown in FIG. 6(A). When the end chucks 45 and 46 have moved over a prescribed distance, the connector part inserter 34 is informed of the arrival of the cores of the optical cables 50A and 50B.
Then, upon receipt of the operation start command, the [0071] connector part chuck 34B of the connector part inserter 34 holds the connector part Cp and fills it with an adhesive and feeds the connector part Cp to the insertion starting position, as shown in FIG. 6(A). The connector part Cp is made of ceramics, for example. If information of the arrival to the connector part insertion position has been received from the controller 31CONT of the robot 31, the movable core guide 34C and the connector part chuck 34B of the connector part inserter 34 move down in the direction of arrow F2, so that the connector part Cp (which is held by the connector part chuck 34B) is slipped on the core of the end of the optical cable, while the core of the optical cable is guided in the center direction of the connector part Cp by the movable core guide 34C. After movement over a prescribed distance, the connector part inserter 34 informs the controller 31CONT of the robot 31 of the completion of the temporary slipping on of the connector part Cp. Incidentally, at the time of the completion of the temporary slipping on, the connector part Cp is not yet slipped on to the final position.
Upon receipt of information of the completion of operation from the [0072] connector part inserter 34, the controller 31CONT of the robot 31 causes the mechanical hand 41 to move upward in the direction of arrow F3, as shown in FIG. 6(B), so as to move the connector part Cp to its final position. The final position is a position at which the forward end of the core protrudes from the central hole of the connector part Cp. The movement in the direction of arrow F3 is accomplished by sliding the axis J0 of the robot 31 in the vertical direction with respect to paper. The completion of the complimentary action of the connector inserter 34 is informed to the connector part inserter 34 by the controller 31CONT.
Upon receipt of information of the completion of the complimentary action from the controller [0073] 31CONT of the robot 31, the connector part inserter 34 moves the dividable movable core guide 34C and the connector part chuck 34B in the respective directions of arrows F4 and F5, as shown in FIG. 6(C), so as to release the connector part Cp (as the work) and informs the controller 31CONT of the robot 31 of the completion of operation.
Then, in response to the signal indicating the completion of operation by the [0074] connector part inserter 34, the robot 31 moves the end chucks 45 and 46 in the direction of arrow F6, as shown in FIG. 6(D), and starts the next step. At the same time the connector part inserter 34 moves the movable core guide 34C and the connector chuck 34B in the direction of arrow F7, thereby helps the discharge by the robot, and then returns to the neutral position to become ready for the next operation.
When the slipping on of the connector part Cp by the [0075] connector part inserter 34 is completed, the connector part Cp is fitted to the forward end of the inner coat 52 and the core 51 protrudes from the center hole of the connector part Cp, as shown in FIG. 4(f).
Then, the horizontal articulated [0076] robot 31 moves the end of the optical cable 50 (which is held by the mechanical hand 40) to the adhesive setter 35. The adhesive setter 35 comprises three identical curing ovens 35A, 35B, and 35C. The controller 31CONT of the robot 31 transfers the end of the optical cable 50 to any of the curing ovens which is not in use. At this time, the end chucks 45A, 45B, 46A, and 46B rotate through 90° in the direction of arrow E1, as shown in FIG. 5(B), and move the optical cable to the curing oven while holding it such that the inner coat 52 points upward.
The [0077] adhesive setter 35 needs heat-curing for more than 20 minutes in the post-finishing step. Therefore, the mechanical hand 40 of the robot 31 transfers the optical cable (as the work) to one of the curing ovens 35A, 35B, and 35C, thereby releasing the robot 31 and allowing the optical cable (as the other work) to be processed. The adhesive to be packed into the connector part Cp is of two-pack type. It cures upon heating at 130° C. for 20 minutes. For the step that requires a long time for processing, the robot transfers the optical cable (as the work) so as to release itself and save the total tact time. The parallel operation of the three curing ovens reduces the tact time. More about tact time will be explained later with reference to FIG. 7.
When the heating step is completed, the [0078] mechanical hand 40 of the horizontal articulated robot 31 receives the optical cable from the curing oven 35 of the adhesive setter 35 and moves the end of the optical cable 50 held thereby to the grinder 36. At this time, the end chucks 45A, 45B, 46A, and 46B rotate through 90° in the direction of arrow E2 and move to the connector part inserter 34, while holding the optical cable such that the end of the core 51 points downward, as shown in FIG. 5(B). The grinder 36 cuts the core 51 protruding (5-10 mm) from the end of the connector part Cp and roughly grinds the end of the connector part Cp, as shown in FIG. 4(f), so as to remove the adhesive which has cured after leakage from the end of the connector part Cp, as shown in FIG. 4(g).
Then, the horizontal articulated [0079] robot 31 moves the end of the optical cable 50 (which is held by the mechanical hand 40) to the polisher 37. At this time, the end chucks 45A, 45B, 46A, and 46B rotate through 90° in the direction of arrow E2 and move to the connector part inserter 34, while holding the optical cable such that the end of the core 51 points downward, as shown in FIG. 5(B). The polisher 37 polishes the end surface of the connector part Cp. The polisher 37 takes 8 minutes for polishing. Therefore, the mechanical hand 40 transfers the optical cable to the polisher 37 temporarily so as to make the robot 31 free. The polisher 37 employs two kinds of polishing paper (rough and fine) so as to polish the end of the connector part Cp, particularly the end of the core 51.
When the polishing by the [0080] polisher 37 is completed, the mechanical hand 40 of the horizontal articulated robot 31 receives the optical cable from the polisher 37 and moves to the unloader 38 to unload the bobbin 60 (as the work).
In what follows, the processing of the post-finishing step of the cable assembler in one embodiment of the present invention is explained with reference to FIG. 7. [0081]
FIG. 7 is a diagram showing what is done by the [0082] post-finishing station 30 of the cable assembler in one embodiment of the present invention.
In FIG. 7, the abscissa represents time, each division denoting 2 minutes, and the ordinate represents devices. In other words, ([0083] 31) at the bottom of the ordinate represents the operating state of the robot 31. (32) on the ordinate represents the loader 32. (33) on the ordinate represents the operating state of the inner coat stripper 33. (34) on the ordinate represents the operating state of the connector part inserter 34. (35) on the ordinate represents the operating state of the adhesive setter 35. The adhesive setter 35 comprises three curing ovens 35A, 35B, and 35C. (36) on the ordinate represents the operating state of the grinder 36. (37) on the ordinate represents the operating state of the polisher 37. (38) on the ordinate represents the unloader 38. Circled alphabets A to H respectively denote the bobbins 60A to 60H which are different works.
First, the horizontal articulated [0084] robot 31 loads the bobbin 60A from the loader 32, and then moves it to the inner coat stripper 33 and executes the stripping of the inner coat. The inner coat stripper 33 takes 2 minutes for its processing. Incidentally, this processing time includes time required for movement from the previous step (the loader 32 in this case) to the inner coat stripper 33. In each step mentioned later, the processing time includes time required for movement from the previous step.
When the inner coat stripping for the bobbin [0085] 60A is completed, the horizontal articulated robot 31 moves the bobbin 60A from the inner coat stripper 33 to the connector part inserter 34, so that the connector part is slipped on. The connector part inserter 34 takes 4 minutes for its processing.
After the bobbin [0086] 60A has undergone the slipping on of the connector part, the horizontal articulated robot 31 moves the bobbin 60A from the connector part inserter 34 to the adhesive setter 35. In this step, the horizontal articulated robot 31 moves the bobbin 60A to the curing oven 35A and transfers the bobbin 60A to the curing oven 35A, so as to make it possible to handle the other work. The curing oven 35A takes 20 minutes for its processing. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60A, as indicated by (31) at the bottom of the ordinate in FIG. 7.
Then, the horizontal articulated [0087] robot 31 loads the bobbin 60B from the loader 32 and moves it to the inner coat stripper 33 for the stripping of the inner coat. After the bobbin 60B has undergone inner coat stripping, the horizontal articulated robot 31 moves the bobbin 60B from the inner coat stripper 33 to the connector part inserter 34 so that the connector part is slipped on. After the bobbin 60B has undergone the slipping on of the connector part, the horizontal articulated robot 31 moves the bobbin 60B from the connector part inserter 34 to the curing oven 35B of the adhesive setter 35 and transfers the bobbin 60B to the curing oven 35B. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60B, as indicated by (31) at the bottom of the ordinate in FIG. 7.
Then, the horizontal articulated [0088] robot 31 loads the bobbin 60C from the loader 32 and moves it to the inner coat stripper 33 for the stripping of the inner coat. After the bobbin 60C has undergone inner coat stripping, the horizontal articulated robot 31 moves the bobbin 60C from the inner coat stripper 33 to the connector part inserter 34 so that the connector part is slipped on. After the bobbin 60C has undergone the slipping on of the connector part, the horizontal articulated robot 31 moves the bobbin 60C from the connector part inserter 34 to the curing oven 35C of the adhesive setter 35 and transfers the bobbin 60C to the curing oven 35C. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60C, as indicated by (31) at the bottom of the ordinate in FIG. 7.
Then, as soon as the bobbin [0089] 60A has undergone the adhesive setting by the curing oven 35A, the horizontal articulated robot 31 receives the bobbin 60A from the curing oven 35A and moves it to the grinder 36. The grinder 36 takes 0.5 minutes for its processing.
After the bobbin [0090] 60A has undergone the grinding step, the horizontal articulated robot 31 moves the bobbin 60A from the grinder 36 to the polisher 37. The polisher 37 takes 8 minutes for its processing. The horizontal articulated robot 31 transfers the bobbin 60A to the polisher 37. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60A, as indicated by (31) at the bottom of the ordinate in FIG. 7.
After the bobbin [0091] 60A has been transferred to the polisher 37, the horizontal articulated robot 31 loads the bobbin 60D from the loader 32 and moves it to the inner coat stripper 33 for the stripping of the inner coat. After the bobbin 60D has undergone inner coat stripping, the horizontal articulated robot 31 moves the bobbin 60D from the inner coat stripper 33 to the connector part inserter 34 so that the connector part is slipped on. After the bobbin 60D has undergone the slipping on of the connector part, the horizontal articulated robot 31 moves the bobbin 60D from the connector part inserter 34 to the curing oven 35A of the adhesive setter 35 and transfers the bobbin 60D to the curing oven 35A. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60D, as indicated by (31) at the bottom of the ordinate in FIG. 7.
After the bobbin [0092] 60D has been transferred to the curing oven 35A, the horizontal articulated robot 31 moves the bobbin 60A from the polisher 37 to the unloader 38 for unloading. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60A, as indicated by (31) at the bottom of the ordinate in FIG. 7.
After the bobbin [0093] 60A has been unloaded, the horizontal articulated robot 31 receives the bobbin 60B from the curing oven 35B and moves it to the grinder 36. (At this stage the bobbin 60B has undergone the adhesive curing in the curing oven 35B.) After the bobbin 60B undergone the grinding step, the horizontal articulated robot 31 moves the bobbin 60B from the grinder 36 to the polisher 37 and transfers the bobbin 60B to the polisher 37. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60B, as indicated by (31) at the bottom of the ordinate in FIG. 7.
After the bobbin [0094] 60B has been transferred to the polisher 37, the horizontal articulated robot 31 loads the bobbin 60E from the loader 32 and moves it to the inner coat stripper 33 for the stripping of the inner coat. After the bobbin 60E has undergone inner coat stripping, the horizontal articulated robot 31 moves the bobbin 60E from the inner coat stripper 33 to the connector part inserter 34 so that the connector part is slipped on. After the bobbin 60E has undergone the slipping on of the connector part, the horizontal articulated robot 31 moves the bobbin 60E from the connector part inserter 34 to the curing oven 35B of the adhesive setter 35 and transfers the bobbin 60E to the curing oven 35B. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60E, as indicated by (31) at the bottom of the ordinate in FIG. 7.
After the bobbin [0095] 60E has been transferred to the curing oven 35B, the horizontal articulated robot 31 moves the bobbin 60B from the polisher 37 to the unloader 38 for unloading. In other words, up to this stage, the horizontal articulated robot 31 handles the bobbin 60B, as indicated by (31) at the bottom of the ordinate in FIG. 7.
The above-mentioned steps are repeated sequentially to perform the terminal processing of the bobbin. The time (Tt) from the unloading of the bobbin [0096] 60A to the unloading of the next bobbin 60B is referred to as the tact time. Similarly, the time (Tt) from the unloading of the bobbin 60B to the unloading of the next bobbin 60C is also tact time. The tact time (Tt) in this illustrative embodiment of the invention is 10 minutes. The time required for each step is as follows: inner coat stripping=2 minutes, connector part insertion=4 minutes, adhesive curing=20 minutes, grinding=0.5 minutes, and polishing=8 minutes. The total time is 34.5 minutes using conventional processing.
However, in accordance with the invention, it is possible to reduce the tact time in the following ways. (1) For the steps (such as adhesive curing and polishing) which take a long time, the robot transfers the bobbin (as the work) to the [0097] adhesive setter 35 and the polisher 37 so as to free itself. (2) The step (such as adhesive curing) which takes a long time is carried out in parallel processing fashion with a plurality of identical units (the curing ovens 35A, 35B, and 35C of the adhesive setter).
Referring to FIG. 7, the time Tx represents the delay between curing completion times between two successive curing ovens, [0098] 35A-35C. Since the curing time in each oven is the same, Tx can alternatively represent the delay between starting times of successive ovens. By staggering the start time of each oven, parallel curing operations can be achieved. The time Tx should be smaller than the desired tact time Tt, in this case 10 minutes. The time Tx can be adjusted by the number of such ovens in use. For the illustrative embodiment shown, it was determined that three such ovens would satisfy the tact time requirement.
Moreover, for a further reduction of the tact time, the controller [0099] 31CONT of the robot 31 has priority for each step, and performs processing according to this priority if there are a plurality of bobbins (as the works) that can be processed simultaneously. The priority (in the descending order) is as follows: (1) unloading the bobbin which has undergone polishing by the polisher 37; (2) moving the bobbin to the polisher 37; and (3) loading a new bobbin.
Execution according to this priority is illustrated in FIG. 7. For example, in the neighborhood of 35 minutes on the abscissa (at which the bobbin [0100] 60D has been transferred to the curing oven 35A), the polishing of the bobbin 60A is completed, and hence the unloading of the bobbin 60A is carried out in preference to the moving of the bobbin 60B to the grinder or the loading of the bobbin 60E according to the rule of priority (1) “the bobbin which has undergone polishing by the polisher 37 is unloaded”. Alternatively, for example, in the neighborhood of 36 minutes on the abscissa (at which the bobbin 60A has been unloaded), the transfer of the bobbin 60B (which has undergone heating) to the grinder 36 and further to the polisher 37 is carried out in preference to the loading of the bobbin 60B to the grinder or the loading of the bobbin 60E according to the rule of priority (2) “the bobbin is moved to the polisher 37”. Furthermore, for example, in the neighborhood of 38 minutes on the abscissa (at which the bobbin 60B has been moved to the polisher 37), the bobbin 60E is loaded according to the rule of priority (3) “a new bobbin is loaded”.
As mentioned above, the present invention makes it possible to carry out in a short tact time the assembling of cable terminal which needs a plurality of jigs and tools. [0101]
Another aspect of the invention is the pipeline fashion processing which can be seen in FIG. 7. In the neighborhood of zero to ten minutes, bobbin [0102] 60A is moved from the coat stripper 33 to connector part inserter 34. At the end of processing in the connector part inserter 34, bobbin 60B is transferred to the coat stripper while bobbin 60A is transferred to a first oven 35A. During curing, bobbin 60B completes processing by the coat stripper 33 and the connector part inserter 34, and is then transferred to a second oven 35B. A similar overlap can be seen in the neighborhood of 28-38 minutes, for example, where bobbin 60A is being polished and bobbin 60D begins its journey. This pipeline processing aspect of the invention allows for shortening of the tact time.
The end chuck of the mechanical hand can change the direction of the member (optical cable) which it grips. This simplifies the mechanism of the processing apparatus and hence reduces the period and expense required for the development of the apparatus. [0103]
Within the working area of the robot, it is possible to handle various kinds of cables by replacing the mechanical hand and adding the units. [0104]
According to the present invention, it is possible to carry out in a short tact time the assembling of cable terminal which needs a plurality of jigs and tools. [0105]

Claims

What is claimed is:

1. A cable assembly method comprising:

obtaining a first bobbin of cable as a first work;

sequentially delivering said first work to each workstation in a first area having one or more workstations;

delivering said first work to a first workstation in a second area having a plurality of workstations, processing times of each workstation in said second area being about equal to each other, said processing time being greater than a total processing time of said one or more workstations in said first work area; and

during processing of said first work in said first workstation:

obtaining a second bobbin of cable as a second work;

sequentially delivering said second work to said one or more workstations in said first area; and

delivering said second work to a second workstation in said second area,

wherein completion of said first work in said first workstation is followed by completion of said second work in said second workstation by a period of time less than said processing time of said workstations in said second area.

2. The method of claim 1 wherein said obtaining steps include manipulating a robotic arm to receive a bobbin of cable disposed in a loader, and said delivering steps include manipulating said robotic arm to transfer said first and second works among said one or more workstations in said first and second areas.

3. The method of claim I further including sequentially delivering said first work to each workstation in a third area having one or more workstations upon completion of processing in said first workstation and then delivering said first work to an unloader, said processing time of said workstations in said second area being greater than a total processing time of said one or more workstations in said third area.

4. The method of claim 1 wherein said workstations in said second work area each provides an identical function.

5. The method of claim 3 further including, subsequent to said delivering said first work to an unloader, delivering said second work to said one or more workstations in said third area and then delivering said second work to said unloader, wherein said first and second works are delivered to said unloader in a time less than said processing time of said workstations in said second area.

6. The method of claim 3 wherein said one or more workstations in said first area include an outercoat stripper and a connector part inserter, said workstations in said second area are curing ovens, and said one or more workstations in said third area include a grinder and a polisher.

7. The method of claim 6 further including delivering a work from said polisher to said unloader prior to delivering a work from said grinder to said polisher, when a work is available at each of said grinder and said polisher, and delivering a work from said grinder to said polisher prior to loading a work to said one or more workstations in said first area, when a work is available at said polisher.

8. A system for assembling cables comprising:

a first work area;

a robotic arm disposed within said first work area;

a first plurality of workstations disposed about said first work area and within reach of said robotic arm;

a loading station for receiving a bobbin of cable as a first work, said loading station disposed within reach of said robotic arm;

a first workstation disposed downstream of said first plurality of workstations;

a second plurality of workstations disposed downstream of said first workstation; and

a controller operatively coupled to said robotic arm, said controller configured to cause said robotic arm:

to retrieve said first work from said loader and to sequentially deliver said first work to said first plurality of workstations, wherein said first work is processed in sequential fashion;

to deliver said first work to said first workstation, said first workstation having a processing time greater than processing times of said first plurality of workstations;

to sequentially deliver said first work to said second plurality of workstations; and

to retrieve a second work from said loader and sequentially deliver said second work to said first plurality of workstations during processing of said first work in said first workstation.

9. The system of claim 8 wherein said first workstation is a first oven.

10. The system of claim 9 further including a second oven, wherein said controller is further configured to deliver said second work to said second oven while said first work is still being processed by said first oven.

11. The system of claim 10 wherein said controller is further configured to deliver said first work from said first oven to said second plurality of workstations while said second work is still in said second oven.

12. The system of claim 8 wherein said first plurality of workstations includes an outer coat stripper and a connector part inserter and said second plurality of workstations includes a grinder and a polisher.

13. The system of claim 8 wherein said robotic arm includes an articulated chuck configured to grip an end portion of said cable and to provide approximately 180° of arcuate range of motion of said end portion in a vertical plane.

14. The system of claim 8 further including a second work area having a second robotic arm disposed therein, a second plurality of workstations disposed in said second work area about said second robotic arm and within reach of said second robotic arm, and a second loading station for receiving said bobbin of cable, wherein said bobbin of cable is processed in said second work area prior to being processed in said first work area.

15. A system for assembling cables comprising:

means for receiving a bobbin of a cable as a first work;

a first means for performing a first plurality of operations on a cable portion of said first work;

a thermal processing means for a thermal treatment of said cable portion, said thermal means having at least a first and a second heating unit;

a second means for performing a second plurality of operations on said cable portion; and

robotic means for delivering said first work to said first means, then to said first heating unit, and then to said second means,

said robotic means configured to deliver a second work to said first means and then to said second heating unit, while said first work is being processed by said first heating unit.

16. The system of claim 15 wherein said robotic means includes a chuck having an approximately 180° arcuate range of motion in a vertical plane, for positioning a cable end portion of said work which is received in said chuck.

17. The system of claim 15 wherein said robotic means is further configured to deliver said first work to said second means while said second work is being processed by said second heating unit.

18. The system of claim 15 wherein said first means includes an outer coat stripper and a connector part inserter and said second means includes a grinder, a polisher, and an unloader.

19. The system of claim 18 wherein said robotic means is further configured to deliver a work from said polisher to said unloader prior to delivering a work from said grinder to said polisher when a work is available at each of said polisher and said grinder, and further configured to deliver a work from said grinder to said polisher prior to loading a work to said first means when a work is available at said polisher.

20. The system of claim 15 further including a third means for performing a third plurality of operations on said cable portion, wherein said first work is processed by said third means and then delivered to said first means.