Abstract
The present invention provides an adhesive application device configured to apply a necessary and sufficient amount of an adhesive to a thin steel strip without causing the problem of increase in the equipment cost. The present invention also provides an apparatus for producing a laminated steel core having the adhesive application device. The present invention further provides a method for producing a laminated steel core. The adhesive application device comprises adhesive application devices (3), (4) that are integrated into a single process, wherein the adhesive application devices (3), (4) are configured to independently apply an adhesive to different locations on the same surface of a thin steel strip (2) at the same or different timings.
Claims
1-10. (canceled)
11. An adhesive application device comprising a plurality of adhesive application devices that are integrated into a single process, wherein the plurality of adhesive application devices are configured to independently apply an adhesive to different locations on the same surface of a thin steel strip at the same or different timings, wherein the plurality of adhesive application devices comprise an inner adhesive application device and an outer adhesive application device, and wherein the outer adhesive application device is arranged to surround the inner adhesive application device.
12. The adhesive application device according to claim 11, further comprising an elevating and lowering mechanism configured to elevate and lower the inner and outer adhesive application devices independently.
13. The adhesive application device according to claim 11, wherein the adhesive application devices are located immediately before a die for punching the thin steel strip into a predetermined shape.
14. The adhesive application device according to claim 12, wherein the adhesive application devices are located immediately before a die for punching the thin steel strip into a predetermined shape.
15. The adhesive application device according to claim 12, further comprising a shock absorber for attenuating the impact of the elevating and lowering movement of the adhesive application devices.
16. The adhesive application device according to claim 13, further comprising a shock absorber for attenuating the impact of the elevating and lowering movement of the adhesive application devices.
17. The adhesive application device according to claim 14, further comprising a shock absorber for attenuating the impact of the elevating and lowering movement of the adhesive application devices.
18. The adhesive application device according to claim 11, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
19. The adhesive application device according to claim 12, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
20. The adhesive application device according to claim 13, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
21. The adhesive application device according to claim 14, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
22. The adhesive application device according to claim 15, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
23. The adhesive application device according to claim 16, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
24. The adhesive application device according to claim 17, further comprising a sensor for sensing the application of the adhesive to the thin steel strip.
25. The adhesive application device according to claim 11, further comprising a heating mechanism for the adhesive.
26. The adhesive application device according to claim 12, further comprising a heating mechanism for the adhesive.
27. The adhesive application device according to claim 13, further comprising a heating mechanism for the adhesive.
28. The adhesive application device according to claim 14, further comprising a heating mechanism for the adhesive.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0031] FIG. 1 is a schematic configuration diagram of an embodiment of an apparatus for producing a laminated steel core comprising an adhesive application device of the present invention and other devices placed in-line before and after the adhesive application device.
[0032] FIG. 2 is a perspective view of an embodiment of the adhesive application device of the present invention.
[0033] FIG. 3 is a plan view of an embodiment of the adhesive application device of the present invention.
[0034] FIG. 4 is a side view of an embodiment of the adhesive application device of the present invention.
[0035] FIG. 5 is a side view of FIG. 4 after removing some of the components.
[0036] FIG. 6 is a front view of an embodiment of the adhesive application device of the present invention.
[0037] FIG. 7 is a front view of FIG. 6 after removing some of the components.
[0038] FIG. 8 is a plan view of an embodiment of adhesive flow passages in the adhesive application device of the present invention.
[0039] FIG. 9 is a plan view of another embodiment of adhesive flow passages in the adhesive application device of the present invention.
[0040] FIG. 10 is a diagrammatic layout of an apparatus for producing a laminated steel core as disclosed in Patent literature 1.
[0041] FIG. 11 is a perspective view of a laminated steel core as disclosed in Patent literature 1.
[0042] FIG. 12 is a plan view of an adhesive application device as disclosed in Patent literature 1.
[0043] FIG. 13 is a diagrammatic layout of a production process using an apparatus for producing a motor as disclosed in Patent literature 2, when rotor cores and stator cores are laminated not by interlocking but by adhesion bonding.
[0044] FIG. 14 is a diagrammatic layout of an apparatus for producing a laminated steel core as disclosed in Patent literature 3.
DESCRIPTION OF EMBODIMENTS
[0045] Embodiments of the present invention will be described below with reference to the attached drawings. Various alterations and modifications are possible within the technical scope of the present invention.
[0046] FIG. 1 is a schematic configuration diagram of an embodiment of an apparatus for producing a laminated steel core comprising the adhesive application device of the present invention and other devices placed in-line before and after the adhesive application device. In the figure, the numeral 1 denotes a coil of a wound thin steel strip 2. The numeral 3 denotes an inner adhesive application device. The numeral 4 denotes an outer adhesive application device. The numeral 5 denotes an elevating and lowering mechanism configured to elevate and lower the inner adhesive application device. The numeral 6 denotes an elevating and lowering mechanism configured to elevate and lower the outer adhesive application device. The numeral 7 denotes an upper die, and the numeral 8 denotes a lower die. The inner and outer adhesive application devices 3, 4 are configured to be independently elevated and lowered by the elevating and lowering mechanisms 5, 6, respectively. The inner and outer adhesive application devices 3, 4 are located immediately before the upper and lower dies as shown in FIG. 1. The thin steel strip 2 is drawn from the coil 1, and an adhesive is applied to the lower surface of the thin steel strip 2 using the inner and outer adhesive application devices 3, 4. The thin steel strip 2 is then punched by the upper and lower dies 7, 8 and optionally subsequent upper and lower dies to create a predetermined shape, and transferred in the direction indicated by the arrow A.
[0047] FIG. 2 is a perspective view of an embodiment of the adhesive application device of the present invention. In the figure, the numeral 10 denotes an adhesive application zone of the inner adhesive application device 3, in which dispense nozzles are annularly arranged. The numeral 11 denotes an adhesive application zone of the outer adhesive application device 4, in which dispense nozzles are annularly arranged. The adhesive application zone 10 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered together with a central circular area 10a and an outer annular area 10b of the inner adhesive application device 3 by one of the elevating and lowering mechanisms (described in detail later). The adhesive application zone 11 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered by another elevating and lowering mechanism. The numeral 12 denotes a plurality of laser sensors for sensing the application of the adhesive to the thin steel strip. The numeral 13 denotes an electromagnetic valve for controlling the elevating and lowering movement of the elevating and lowering mechanisms configured to elevate and lower the inner and outer adhesive application devices. The numeral 14 denotes cartridge heaters for increasing the temperature of the adhesive. The numeral 15 denotes a temperature sensor for sensing the temperature of the inner adhesive application device 3 comprising the adhesive application zone 10 in which the dispense nozzles are annularly arranged and the central circular area 10a and the outer annular area 10b. The numeral 16 denotes a temperature sensor for sensing the temperature of the outer adhesive application device 4 comprising the adhesive application zone 11 in which the dispense nozzles are annularly arranged.
[0048] FIG. 3 is a plan view of an embodiment of the adhesive application device of the present invention. The numeral 17 denotes supply ports for supplying the adhesive to the adhesive application zone 10 of the inner adhesive application device 3, in which the dispense nozzles are annularly arranged. The numeral 18 denotes supply ports for supplying the adhesive to the adhesive application zone 11 of the outer adhesive application device 4, in which the dispense nozzles are annularly arranged. The supply ports 17, 18 are detachable.
[0049] FIG. 4 is a side view of an embodiment of the adhesive application device of the present invention. The numeral 19 denotes shock absorbers for attenuating the impact of the elevating and lowering movement of the outer adhesive application device 4 comprising the adhesive application zone 11 in which the dispense nozzles are annularly arranged. The numeral 20 denotes shock absorbers for attenuating the impact of the elevating and lowering movement of the inner adhesive application device 3 comprising the adhesive application zone 10 in which the dispense nozzles are annularly arranged and the central circular area 10a and the outer annular area 10b.
[0050] FIG. 6 is a front view of an embodiment of the adhesive application device of the present invention. The numeral 21 denotes air cylinders for elevating and lowering the outer adhesive application device 4 comprising the adhesive application zone 11 in which the dispense nozzles are annularly arranged. The numeral 22 denotes an air cylinder for elevating and lowering the inner adhesive application device 3 comprising the adhesive application zone 10 in which the dispense nozzles are annularly arranged and the central circular area 10a and the outer annular area 10b. The numeral 23 denotes a photomicrosensor for sensing the upper and lower limits of the movement of the air cylinders 21. The numeral 24 denotes a photomicrosensor for sensing the upper and lower limits of the movement of the air cylinder 22. The adhesive application device is provided with more than one air cylinder 21 and more than one air cylinder 22.
[0051] FIG. 8 is a plan view of an embodiment of adhesive flow passages in the adhesive application device of the present invention. The width d of the flow passages 25 in this embodiment is constant along its entire length. The adhesive is supplied through the flow passages 25, and dispensed from dispense nozzles 26, 27 on the adhesive application zones 10, 11 in which the dispense nozzles are annularly arranged as shown in FIG. 3. FIG. 9 is a plan view of another embodiment of adhesive flow passages in the adhesive application device of the present invention. The width w of the flow passages 28 in this embodiment is tapered toward the outlets of the flow passages 28. When the length of the flow passages is relatively long, such tapered flow passages are advantageous in that the adhesive can be easily delivered to the outlets of the flow passages. In FIGS. 1 to 3, the adhesive application zones 10, 11 in which the dispense nozzles are annularly arranged (on the top surfaces of the adhesive application devices) are positioned slightly lower than the top surface of the lower die 8. Such adhesive application zones 10, 11 positioned to be recessed from the top surface of the lower die 8 are advantageous in that the adhesive dispensed from the dispense nozzles 26, 27 is not immediately applied to the lower surface of the thin steel strip (indicated by the numeral 2 in FIG. 1), but the adhesive rising on the dispense nozzles 26, 27 is applied to the lower surface of the thin steel strip so that the amount of the adhesive applied is constant.
[0052] A method for applying an adhesive to a thin steel strip using the adhesive application device configured as described above will be described below.
[0053] The adhesive is not continuously applied to the thin steel strip 2, but is rather applied to the thin steel strip 2 in synchronization with the timing of punching the thin steel strip 2 into a predetermined shape by lowering the upper die 7 toward the lower die 8 in the configuration as shown FIG. 1. In particular, when referring to FIG. 1, at the timing when punching is not performed, a predetermined distance (about several millimeters) is provided between the thin steel strip 2 and the components of the apparatus for producing a laminated steel core, including the top surface of the inner adhesive application device 3, the top surface of the outer adhesive application device 4, the top surfaces of platforms 9a, 9b and the top surface of the lower die 8. In the configuration shown in the figure, at the timing when the upper die 7 is lowered toward the lower die 8 to punch the thin steel strip 2 into a predetermined shape, the thin steel strip 2 is pressed against the lower die 8. Since the inner and outer adhesive application devices 3, 4 are configured to be independently elevated and lowered, the inner and outer adhesive application devices 3, 4 can independently be elevated to a height at which the top surfaces of the inner and outer adhesive application devices are positioned slightly lower than the lower surface of the thin steel strip 2. The adhesive stored in a tank (not shown) is constantly supplied to the inner and outer adhesive application devices 3, 4 at a predetermined pressure, and is applied to the lower surface of the thin steel strip 2.
[0054] After the adhesive is applied to the lower surface of the thin steel strip 2 as described above, the thin steel strip 2 is punched by the upper and lower dies 7, 8 and optionally subsequent upper and lower dies into a predetermined shape to produce steel core sheets. The steel core sheets having a predetermined shape are stacked on top of one another within the lower die 8 or an optionally subsequent lower die. After the stacked core sheets reach a predetermined number, the stacked core sheets are dispensed from the lower die 8 or an optionally subsequent lower die. The stacked core sheets are subjected to a given post-treatment such as heating, and used for the assembly of electric parts . For example, when referring to FIG. 1, at the timing of punching the thin steel strip 2 into a predetermined shape by lowering the upper die 7 toward the lower die 8, only the inner adhesive application device 3 is elevated toward the lower surface of the thin steel strip 2 to apply the adhesive to the lower surface of the thin steel strip 2. The adhesive-applied thin steel strip 2 is punched by the upper and lower dies 7, 8 into a predetermined shape to produce a steel core sheet. The steel core sheet is stacked on another steel core sheet within the lower die 8. Then, at the timing of punching the thin steel strip 2 into a predetermined shape by lowering an optionally subsequent upper die toward an optionally subsequent lower die, only the outer adhesive application device 4 is elevated toward the lower surface of the thin steel strip 2 to apply the adhesive to the lower surface of the thin steel strip 2. The adhesive-applied thin steel strip 2 is punched by the subsequent upper and lower dies into a predetermined shape to produce a steel core sheet. The steel core sheet is stacked on another steel core sheet within the lower die.
[0055] The adhesive is supplied from a tank (not shown) at a predetermined pressure toward the inner and outer adhesive application devices 3, 4 as described above, and reaches the supply ports 17, 18 as shown in FIG. 3. The adhesive is then dispensed from the dispense nozzles 26 of the adhesive application zone 10 in which the dispense nozzles are annularly arranged and from the dispense nozzles 27 of the adhesive application zone 11 in which the dispense nozzles are annularly arranged, and is applied to the lower surface of the thin steel strip. The adhesive application zone 10 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered together with the central circular area 10a and the outer annular area 10b by one of the elevating and lowering mechanisms (described in detail later). The adhesive application zone 11 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered by another elevating and lowering mechanism. In this manner, the inner and outer adhesive application devices 3, 4 are integrated into a single apparatus, and the inner and outer adhesive application devices may be configured to be independently elevated and lowered. Due to this configuration, miniaturization of the adhesive application devices, the dies and the apparatus for producing a laminated steel core can be achieved and the configuration of the apparatus can be simplified, which may lead to a significant reduction in the equipment cost, as compared with the conventional apparatus for producing a laminated steel core as shown in FIG. 13.
[0056] Specifically, in the inner adhesive application device 3, the adhesive application zone 10 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered together with the central circular area 10a and the outer annular area 10b by the air cylinder 22 as shown in FIG. 6. In the outer adhesive application device 4, the adhesive application zone 11 in which the dispense nozzles are annularly arranged is configured to be elevated and lowered by the air cylinders 21 as shown in FIG. 6.
[0057] When a laminated core as shown in FIG. 11 is intended to be produced, a necessary and sufficient amount of the adhesive is applied to the lower surface of the thin steel strip by switching the plurality of adhesive application devices as needed. The present invention can be used to produce not only a concentric laminated core but also a laminated core that is partitioned in the circumferential direction or other types of laminated cores.
[0058] The movement of the air cylinders 21, 22 is controlled by the electromagnetic valve 13 as shown in FIG. 2. The upper and lower limits of the elevating and lowering movement of the air cylinders are sensed by the photomicrosensors 23, 24 as shown in FIG. 6. The shock absorbers 19, 20 as shown in FIG. 4 attenuate the impact of the elevating and lowering movement on the components of the apparatus and shorten a waiting time until the vibration by the impact stops.
[0059] The adhesive application device of the invention comprises the plurality of laser sensors 12 for sensing the application of the adhesive to the thin steel strip as shown in FIG. 2. When the laser sensors 12 detect that the adhesive application device has failed to apply the adhesive to the thin steel strip, this information detected by the laser sensors 12 is sent as a feedback to the tank (not shown) storing the adhesive, and supply of the adhesive to the inner and outer adhesive application devices 3, 4 is stopped to allow the operator to carry out necessary procedures such as inspection and repair.
[0060] Referring back to FIG. 2, the cartridge heaters 14 for increasing the temperature of the adhesive are coupled to a power supply (not shown). By heating the adhesive with the cartridge heaters 14, the fluidity of the adhesive can be increased and the adhesive can be stably dispensed from the dispense nozzles 26, 27 as shown in FIG. 3. The temperature sensors 15, 16 can sense an abnormal rise in the temperature in the apparatuses, and based on the detected temperature, the number of the cartridge heaters 14 in operation can be adjusted as needed. Since the inner and outer adhesive application devices 3, 4 are located outside the upper and lower dies 7, 8, the temperature rise by the cartridge heaters 14 has no influence on the dies, and simultaneously, temperature changes in the dies have no influence on the fluidity of the adhesive.
INDUSTRIAL APPLICABILITY
[0061] The adhesive application device of the present invention can be used to apply an adhesive to a thin steel strip for the production of laminated steel cores for stepper motors or motor cores.
REFERENCE SIGNS LIST
[0062] 1 Coil [0063] 2 Thin steel strip [0064] 3 Inner adhesive application device [0065] 4 Outer adhesive application device [0066] 5 Elevating and lowering mechanism for inner adhesive application device [0067] 6 Elevating and lowering mechanism for outer adhesive application device [0068] 7 Upper die [0069] 8 Lower die [0070] 9a, 9b Platforms [0071] 10 Adhesive application zone in which dispense nozzles are annularly arranged [0072] 10a Central circular area [0073] 10b Outer annular area [0074] 11 Adhesive application zone in which dispense nozzles are annularly arranged [0075] 12 Laser sensors [0076] 13 Electromagnetic valve [0077] 14 Cartridge heaters [0078] 15, 16 Temperature sensors [0079] 17, 18 Adhesive supply ports [0080] 19, 20 Shock absorbers [0081] 21, 22 Air cylinders [0082] 23, 24 Photomicrosensors [0083] 25, 28 Flow passages [0084] 26, 27 Dispense nozzles
