Processing oil supply method and device

Abstract

To provide a processing oil supply method that can suppress expansion of a gap between adjacent iron core pieces due to a processing oil remaining in a crimped part.SOLUTION: A processing oil OL is injected to a crimping planned part 5b which serves as a crimped part 7a of a steel plate 5 and a punching planned part 5c which serves as punched parts 7c, 7d and 7e. At least one of injection quantity and viscosity of the processing oil OL differs between the crimping planned part 5b and the punching planned part 5b. The injection quantity of the processing oil OL is differed so as to relatively decrease at the crimping planned part 5b, and the viscosity of the processing oil OL is differed so as to relatively decrease at the crimping planed part 5b.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a machining oil supply method and apparatus for supplying machining oil when forming a core piece used for a laminated core of a rotating electrical machine from a steel plate.

Background Art

[0002] As a laminated core of a rotating electrical machine, for example, as in Patent Document 1, a plurality of disk-shaped core pieces are each punched from a steel plate by pressing, and these core pieces are laminated and integrated by caulking.

[0003] Caulking is performed by caulking portions provided on each core piece. The caulking portion is formed by pressing, with one side being a concave portion and the other side being a convex portion. By this caulking portion, adjacent core pieces are caulked together. That is, the convex portion of the caulking portion of one core piece fits into the concave portion of the caulking portion of the other core piece.

[0004] When punching such core pieces and forming the caulking portions, it is common to supply machining oil to the steel plate from the viewpoint of protecting the press die. The supply of this machining oil is performed on the entire portion that becomes the core piece by spraying or the like.

[0005] However, in such a machining oil supply method, since the machining oil remaining in the caulking portion forms an oil film between the concave and convex portions during caulking of adjacent core pieces, there is a problem that the gap between adjacent core pieces expands according to the thickness of the oil film.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved is that it is impossible to suppress the expansion of the gap between adjacent core pieces due to the processing oil remaining in the caulked portion.

Means for Solving the Problem

[0008] The present invention is a processing oil supply method for supplying processing oil when forming a core piece having a caulked portion with one side being a concave portion and the other side being a convex portion and a punching portion by punching from a steel sheet, wherein the processing oil is sprayed onto a caulking planned portion that will become the caulked portion of the steel sheet and a punching planned portion that will become the punching portion, and at least one of the injection amount and viscosity of the processing oil is made different between the caulking planned portion and the punching planned portion. In the case of the injection amount of the processing oil, it is made different so as to be relatively less in the caulking planned portion, and in the case of the viscosity of the processing oil, it is made different so as to be relatively lower in the caulking planned portion. A processing oil supply method is provided.

[0009] Further, the present invention is a processing oil supply device for supplying processing oil when forming a core piece having a caulked portion with one side being a concave portion and the other side being a convex portion and a punching portion by punching from a steel sheet, comprising an injection device for injecting the processing oil onto a caulking planned portion that will become the caulked portion of the steel sheet and a punching planned portion that will become the punching portion, and the injection device makes at least one of the injection amount and viscosity of the processing oil different between the caulking planned portion and the punching planned portion. In the case of the injection amount of the processing oil, it is made different so as to be relatively less in the caulking planned portion, and in the case of the viscosity of the processing oil, it is made different so as to be relatively lower in the caulking planned portion. A processing oil supply device is provided.

Effects of the Invention

[0010] According to the present invention, it is possible to suppress the expansion of the gap between adjacent core pieces due to the processing oil remaining in the caulked portion.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0012] The object of suppressing the expansion of the gap between adjacent core pieces due to the machining oil remaining in the caulking part was achieved by varying the injection amount or viscosity of the machining oil between the caulking planned part that becomes the caulking part of the steel sheet and the punching planned part that becomes the punching part.

[0013] The processing oil supply method is for supplying processing oil OL when forming a core piece 7 having a caulking portion 7a with a concave portion 7aa on one side and a convex portion 7ab on the other side, and punching portions 7c, 7d, and 7e by punching, and sprays the processing oil OL onto a caulking planned portion 5b that becomes the caulking portion 7a of the steel plate 5 and punching planned portions 5c that become the punching portions 7c, 7d, and 7e.

[0014] The processing oil OL is made to differ in at least one of the injection amount and the viscosity between the caulking planned portion 5b and the punching planned portion 5c. In the case of the injection amount of the processing oil OL, it is made to differ so as to be relatively less in the caulking planned portion 5b, and in the case of the viscosity of the processing oil OL, it is made to differ so as to be relatively lower in the caulking planned portion 5b.

[0015] The processing oil OL may be selectively injected from a plurality of injection portions 19. In this case, the injection amount of the processing oil OL is set according to the number of the injection portions 19.

[0016] The injection of the processing oil OL may be performed from a plurality of first injection portions 19a and a plurality of second injection portions 19b while feeding the steel plate 5. The plurality of first injection portions 19a and the plurality of second injection portions 19b are in a row along the width direction of the steel plate 5 and are shifted in the feeding direction and the width direction.

[0017] As another embodiment, the injection of the processing oil OL may be performed from the plurality of first injection portions 19a and the plurality of second injection portions 19b to the caulking planned portion 5b and the punching planned portion 5c, respectively. The plurality of first injection portions 19a and the plurality of second injection portions 19b are in a row along the width direction of the steel plate 5.

[0018] The processing oil OL is injected onto at least one of the front and back surfaces of the caulking planned portion 5b and the punching planned portion 5c. Preferably, the processing oil OL is injected onto both the front and back surfaces of the caulking planned portion 5b and the punching planned portion 5c.

[0019] The processing oil supply device 11 includes an injection device 17. The injection device 17 injects processing oil onto the caulking planned portion 5b that becomes the caulking portion 7a of the steel plate 5 and the punching planned portions 5c that become the punching portions 7c, 7d, and 7e. This injection device 17 makes at least one of the injection amount and viscosity of the processing oil OL different between the caulking planned portion 5b and the punching planned portion 5c. In the case of the injection amount of the processing oil OL, it is made different so as to be relatively less in the caulking planned portion 5b. In the case of the viscosity of the processing oil OL, it is made different so as to be relatively lower in the caulking planned portion 5b.

[0020] The processing oil supply device 11 may include a plurality of injection units 19 that selectively inject the processing oil OL, and the injection amount of the processing oil OL may be set according to the number of the injection units 19.

[0021] The injection device 17 may include a plurality of first injection units 19a arranged in a row along the width direction of the steel plate 5 and a plurality of second injection units 19b arranged in a row along the width direction and shifted in the feeding direction and width direction of the steel plate 5 with respect to the first injection units 19a.

[0022] As another embodiment, the injection device 17 includes a plurality of first injection units 19a arranged in a row along the width direction of the steel plate 5 and a plurality of second injection units 19b arranged in a row along the width direction, and the first injection units 19a and the second injection units 19b may inject the processing oil OL onto the caulking planned portion 5b and the punching planned portion 5c, respectively.

[0023] The injection device 17 preferably injects the processing oil by an inkjet method.

Example

[0024] [Configuration of Manufacturing Device] FIG. 1 is a schematic side view showing a cross-section of a part of a manufacturing device of a laminated core provided with a processing oil supply device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the laminated core. FIG. 3 is a plan view showing a steel plate on which punching is performed by the manufacturing device of FIG. 1.

[0025] The manufacturing apparatus 3 for the laminated core 1 in Fig. 1 manufactures a laminated core which is a core of a rotating electrical machine such as an electric motor or a generator. The laminated core 1 may be a rotor core or a stator core. In this manufacturing apparatus 3, a plurality of disc-shaped core pieces 7 are sequentially punched out from a steel sheet 5 which is an electromagnetic steel sheet or a silicon steel sheet intermittently supplied, and laminated to form the laminated core 1.

[0026] As shown in Fig. 2, adjacent core pieces 7 of the laminated core 1 are joined by caulking. The caulking is performed by caulking portions 7a formed on each core piece 7.

[0027] The caulking portion 7a has both sides in the width direction separated from the main body portion 7b of the core piece 7, and both sides in the longitudinal direction are integrated with the main body portion 7b. The intermediate portion in the longitudinal direction of this caulking portion 7a is bent to form a concave portion 7aa on one side in the plate thickness direction and a convex portion 7ab on the other side. Note that the shape of the caulking portion 7a can be set as appropriate, and it may be a cantilever shape provided radially from the outer edge of the core piece 7 or the like.

[0028] This caulking portion 7a has the convex portion 7ab of the caulking portion 7a of one core piece 7 fitting into the concave portion 7aa of the caulking portion 7a of the other adjacent core piece 7. By this fitting, the adjacent core pieces 7 are joined by caulking. An oil film is formed between the convex portion 7ab and the concave portion 7aa by a processing oil OL described later.

[0029] In addition to the caulking portion 7a, each core piece 7 has an inner circumference 7c, an outer circumference 7d, and a magnet insertion hole 7e (see Fig. 3) etc. formed as punching portions by punching. Note that as punching portions, when the laminated core 1 is a stator core, slots etc. are also included.

[0030] The manufacturing apparatus 3 in Fig. 1 includes a feeding device 9, a processing oil supply device 11, a die device 13, and a control unit 15.

[0031] The feeding device 9 intermittently feeds the steel plate 5. The feeding device 9 can have an appropriate configuration, but in this embodiment, it is provided with a pair of feeding rollers 9a. The feeding rollers 9a feed the steel plate 5 by rotating while sandwiching the steel plate 5 therebetween. The driving of the feeding rollers 9a is performed by a servo motor or the like (not shown).

[0032] FIGS. 4(A) and (B) show the injection device 17 of the processing oil supply device 11 used in the manufacturing device 1 of FIG. 1. FIG. 4(A) is a schematic front view, and FIG. 4(B) is a schematic side view.

[0033] As shown in FIGS. 1, 3, and 4, the processing oil supply device 11 supplies the processing oil OL when forming the core piece 7 from the steel plate 5. The type of the processing oil OL is not particularly limited, but it may be a generally available press oil or the like.

[0034] This processing oil supply device 11 includes an injection device 17. The injection device 17 injects the processing oil OL onto the caulking planned portion 5b (see FIG. 5) that becomes the caulking portion 7a of the steel plate 5 and the punching planned portion 5c (see FIG. 5) that becomes the punching portion.

[0035] The injection device 17 includes a plurality of injection portions 19 that inject the processing oil. The injection portion 19 injects the processing oil supplied from a supply source such as a tank of the processing oil by a pump or the like. The plurality of injection portions 19 are arranged in a row along the width direction of the steel plate 5. As shown in FIG. 3, the injection device 17 is larger than the outer diameter of the core piece portion 5a punched out as the core piece 7, and the injection portion 19 enables the injection of the processing oil at a plurality of injection positions covering the outer diameter of the core piece portion 5a.

[0036] Therefore, in this embodiment, the injection portion 19 can cover the entire area of the core piece portion 5a according to the feeding of the steel plate 5. Accordingly, the injection device 17 can supply the processing oil OL to an arbitrary location of the core piece portion 5a by selectively using the injection portion 19.

[0037] Such an injection device 17 makes the injection amount of the processing oil OL different between the caulking planned part 5b and the removal planned part 5c, and makes the injection amount of the processing oil relatively less in the caulking planned part 5b. The injection amount of the processing oil OL is the volume of the processing oil OL injected per unit area. The adjustment of the injection amount can be performed by controlling the injection ability of each injection part 19.

[0038] The control of the injection ability of this injection part 19 can be performed, for example, by configuring each injection part 19 to have a valve and a nozzle and opening and closing the valve. Alternatively, this control can be performed by making the injection part 19 an inkjet method as in the third embodiment and controlling the injection part 19 that performs injection and its injection ability.

[0039] The mold device 13 includes an upper mold 21 and a lower mold 23. The upper mold 21 is configured to be movable up and down with respect to the lower mold 23, and by descending, performs press working on the caulking part 7a, the inner and outer circumferences 7c and 7d, and the magnet insertion hole 7e by the punch 25.

[0040] The punch 25 is provided so as to protrude downward from the upper mold 21, and the tip thereof passes through the stripper plate 27. The tip of the punch 25 is configured by a flat surface along the width direction and the feed direction orthogonal to the vertical direction.

[0041] The stripper plate 27 is supported by a biasing member such as a spring with respect to the upper mold 21, and is movable toward the upper mold 21 against the biasing force. When the upper mold 21 descends, the stripper plate 27 comes into contact with the steel plate 5. In this state, when the upper mold 21 further descends, the punch 25 protrudes with respect to the stripper plate 27 and press working is performed.

[0042] The punch 25 of the upper mold 21 includes a first punch 25a for the inner circumference 7c and the magnet insertion hole 7e of the iron core piece 7 in FIG. 3, a second punch 25b for the caulking part 7a, and a third punch 25c for the outer circumference 7d.

[0043] In such a punch 25, after the inner circumference 7c and the magnet insertion hole 7e of the core piece portion 5a are punched by the first punch 25a, the caulking portion 7a of the core piece portion 5a is formed by the second punch 25b according to the feeding of the steel sheet 5. Then, when the outer circumference of the core piece portion 5a is punched by the third punch 25c, the core piece portion 5a is punched out from the steel sheet 5 as the core piece 7. The punched core piece 7 is held as it is in the die 29 of the lower die 23.

[0044] The lower die 23 is provided with a die 29 for punching and holding the core piece 7 corresponding to the third punch 25c. The lower die 23 is also provided with a die (not shown) corresponding to the first punch 25a and the second punch 25b.

[0045] The die 29 of this embodiment includes a die main body portion 29a and a squeeze ring 29b.

[0046] The die main body portion 29a is formed in a ring shape and is fixed to the inner circumference of the support hole 23a of the lower die 23. The squeeze ring 29b is arranged adjacent to the die main body portion 29a in the punching direction of the core piece 7 and is supported by the inner circumference of the support hole 23a in the same manner as the die main body portion 29a. The squeeze ring 29b is formed in a ring shape that is longer than the die main body portion 29a in the punching direction.

[0047] The punching direction coincides with the axial direction of the core piece 7 and is the vertical direction in this embodiment. However, the punching direction and the axial direction do not necessarily have to be the vertical direction.

[0048] This squeeze ring 29b is a portion that applies side pressure and holds the punched core piece 7 by pressing it from the outer circumference. It is also possible to omit the squeeze ring 29b. In this case, the die main body portion 29a may be extended in the punching direction, or the support hole 23a of the lower die 23 may be reduced in diameter to provide the function of the squeeze ring 29b.

[0049] Within the squeeze ring 29b, a stacked core 1 is formed by stacking a predetermined number of held core pieces 7 while being caulked to each other by caulking portions 7a. Note that a block having a stacking height lower than that of the stacked core 1 may be formed. The block forms the stacked core 1 by stacking a plurality of them. The plurality of core pieces 7 constituting the stacked core 1 are stacked coaxially without different phases.

[0050] The control unit 15 is an information processing device having a processor and a memory, and controls each part of the manufacturing device 3. By this control, the machining oil supply method of the present embodiment is realized. Note that the control unit 15 may be not only a single information processing device but also a combination of a plurality of information processing devices.

[0051] [Operation of Manufacturing Device] Hereinafter, the machining oil supply method will be described together with the operation of the manufacturing device 3. FIG. 5 is a plan view of a steel plate showing an example of an injection position by the machining oil supply device according to the embodiment.

[0052] In the manufacturing device 3 of the present embodiment, as shown in FIG. 5, first, machining oil is injected into a caulking planned portion 5b that becomes a caulking portion 7a of the steel plate 5 and a punching planned portion 5c that becomes a punching portion.

[0053] Specifically, a core piece portion 5a that is punched out as a core piece 7 by feeding the steel plate 5 is supplied to the machining oil supply device 11. In the machining oil supply device 11, machining oil is injected from the front and back surfaces to the caulking planned portion 5b and the punching planned portion 5c of the core piece portion 5a.

[0054] The injection amount of the machining oil OL is made different between the caulking planned portion 5b and the punching planned portion 5c, and is made relatively less in the caulking planned portion 5b. The caulking planned portion 5b has less portion to be sheared with respect to the punching planned portion 5c, and the load during press working is small. For this reason, the caulking planned portion 5b can reduce the injection amount of the machining oil compared to the punching planned portion 5c.

[0055] The actual injection position of the processing oil OL may be at the caulking planned portion 5b, the punching planned portion 5c, or their peripheries. That is, since the processing oil OL extends and spreads during press working, it suffices if it reaches the caulking planned portion 5b and the punching planned portion 5c as a result.

[0056] Therefore, as long as the processing oil OL can be extended and spread to the caulking planned portion 5b and the punching planned portion 5c, injecting the processing oil OL around the caulking planned portion 5b and the punching planned portion 5c is also included in injecting the processing oil OL into the caulking planned portion 5b and the punching planned portion 5c. The injection position of the processing oil OL can be appropriately set according to the viscosity and injection amount of the processing oil OL.

[0057] Such injection of the processing oil OL is performed on the entire caulking planned portion 5b and punching planned portion 5c of the core piece portion 5a while feeding the steel sheet 5.

[0058] The core piece portion 5a onto which the processing oil OL is injected is supplied to the die device 13 by feeding the steel sheet 5. In the die device 13, first, the inner circumference 7c and the magnet insertion hole 7e are punched in the core piece portion 5a of the steel sheet 5 by the first punch 25a.

[0059] The core piece portion 5a in which the inner circumference 7c and the magnet insertion hole 7e are punched is supplied to the second punch 25b by feeding the steel sheet 5. Then, a caulking portion 7a is formed in the core piece portion 5a by the second punch 25b. After that, the core piece portion 5a is supplied to the third punch 25c by feeding the steel sheet 5.

[0060] The third punch 25c punches out the outer circumference 7d of the core piece portion 5a and punches out the core piece portion 5a from the steel sheet 5 as the core piece 7. The punched-out core piece 7 is held in the die 29 as it is and laminated on the core piece 7 that has been punched out earlier and held in the die 29.

[0061] At this time, the convex portion 7ab of the caulking portion 7a of the subsequent core piece 7 fits into the concave portion 7aa of the caulking portion 7a of the preceding core piece 7. At the time of this fitting, although the processing oil OL remains in the caulking portion 7a, since the injection amount of the processing oil OL to the caulking planned portion 5b is relatively small, the remaining amount of the processing oil OL in the caulking portion 7a is also relatively small.

[0062] Therefore, in this embodiment, the thickness of the oil film between the concave portion 7aa and the convex portion 7ab can be reduced, and as a result, the expansion of the gap between the adjacent core pieces 7 can be suppressed. Accordingly, the height of the laminated core 1 can be stabilized, and the rigidity and the occupation ratio of the laminated core 1 can be improved, and the characteristics of the rotating electrical machine by the manufactured laminated core 1 can be improved.

[0063] Also, when the processing oil OL is injected around the caulking planned portion 5b, as a result of the processing oil OL spreading, the remaining amount of the processing oil at the caulking portion 7a can be further reduced. Therefore, the expansion of the gap between the adjacent core pieces 7 can be more reliably suppressed.

[0064] Further, in this embodiment, the processing oil OL is basically not injected into the portions where press working other than the caulking planned portion 5b and the punching planned portion 5c is not performed. For this reason, the amount of the processing oil used can be reduced and the oil removal process can be reduced. Also, no matter where the processing oil OL is applied to the caulking planned portion 5b, the punching planned portion 5c, and the periphery thereof, the processing oil OL easily spreads, and the remaining amount of the processing oil at the caulking portion 7a can be further reduced. Therefore, the expansion of the gap between the adjacent core pieces 7 can be more reliably suppressed.

[0065] Furthermore, in this embodiment, since the processing oil OL is not supplied to the caulking planned portion 5b and the punching planned portion 5c more than necessary, the processing oil does not become excessive, and the processing accuracy can be improved.

[0066] Also, in this embodiment, since the processing oil OL is injected onto the front and back surfaces of the caulking planned portion 5b and the punching planned portion 5c, the processing oil can be supplied to and protected on both the punch 25 and the die 29.

[0067] [Modification Example] Figs. 6 to 8 are plan views of a steel plate showing an example of the injection position by the machining oil supply device according to a modified example of Example 1.

[0068] The machining oil supply device 11 according to the modified example adjusts the injection amount of the machining oil OL by the injector 17 according to the number of injection times. For example, as shown in Fig. 6 or Fig. 7, the caulking planned portion 5b of the core piece portion 5a of the steel plate 5 is injected with the machining oil OL once, and the punching planned portion 5c is injected with the machining oil OL twice.

[0069] In Fig. 6, the two injections of the machining oil OL for the punching planned portion 5c are performed from the same injection portion 19. In Fig. 7, the two injections of the machining oil OL for the punching planned portion 5c are performed by the injection portions 19 adjacent in the width direction of the steel plate 5. The number of injection times can be set arbitrarily.

[0070] In Fig. 8, the caulking planned portion 5b is injected with the machining oil OL once, and the punching planned portion 5c is injected with the machining oil OL four times. In the case of Fig. 8, among the four injections of the machining oil OL for the punching planned portion 5c, two adjacent injections in the width direction are performed by the injection portions 19 adjacent in the width direction of the steel plate 5, and this is performed twice in the feed direction.

[0071] The injection capacity of the injection portion 19 may be made smaller for the injection portion 19 for the caulking planned portion 5b than for the injection portion 19 for the punching planned portion 5c. Alternatively, the injection capacity of each injection portion 19 may be constant.

[0072] In such a modified example, the injection amount of the machining oil OL can be adjusted only by the on-off control of the injection portion 19. In addition, in the modified example as well, the same operational effects as those of Example 1 can be achieved.

Example

[0073] Figs. 9(A) and (B) show the injection part of the machining oil supply device according to Example 2 of the present invention. Fig. 9(A) is a schematic front view, and Fig. 9(B) is a schematic side view. Figs. 10(A) and (B) show an example of the injection position of the machining oil according to Example 2. In Example 2, since the basic configuration is common to Example 1, the corresponding components are denoted by the same reference numerals and redundant descriptions are omitted. For the overall configuration of Example 2, refer to Fig. 1.

[0074] In the machining oil supply device 11 of this embodiment, the injection device 17 includes a plurality of first injection parts 19a and a plurality of second injection parts 19b. The first injection part 19a is located on the upstream side in the feeding direction, and the second injection part 19b is located on the downstream side in the feeding direction.

[0075] The plurality of first injection parts 19a and the plurality of second injection parts 19b are arranged in a row in the width direction of the steel plate 5. These first injection parts 19a and second injection parts 19b are displaced in the feeding direction and the width direction, and when viewed from the front in Fig. 9(A), the first injection parts 19a are located between the second injection parts 19b.

[0076] In such a configuration, as shown in Figs. 10(A) and 10(B), after the machining oil OL is injected by the first injection part 19a, the machining oil OL is injected by the second injection part 19b between the injection positions by the first injection part 19a. Thereby, the machining oil OL can be injected at a finer pitch in the width direction of the steel plate 5. In addition, in this embodiment as well, the same operational effects as those of Example 1 can be achieved.

[0077] [Modification Example] Fig. 11 is a plan view of a steel plate showing an example of an injection position by a machining oil supply device according to a modification example of Example 2.

[0078] In the modification example of Fig. 11, the plurality of first injection parts 19a and the plurality of second injection parts 19b of the injection device 17 inject machining oils OL having different viscosities into the caulking planned part 5b (see Fig. 5) and the punching planned part 5c (see Fig. 5), respectively.

[0079] In addition, in this modified example, the first injection part 19a and the second injection part 19b are arranged in a row along the width direction. These first injection part 19a and second injection part 19b are not shifted from each other in the width direction and overlap in the feed direction. However, the first injection part 19a and the second injection part 19b may be arranged with a shift in the width direction.

[0080] In such a modified example, low-viscosity processing oil is injected from the first injection part 19a, and high-viscosity processing oil is injected from the second injection part 19b. Thereby, the injection device 17 of this modified example makes the viscosity of the processing oil OL different between the caulking planned part 5b and the punching planned part 5c, and makes the viscosity of the processing oil relatively lower in the caulking planned part 5b.

[0081] Note that the injection amount of the processing oil may be the same between the caulking planned part 5b and the punching planned part 5c or may be different as in the first embodiment.

[0082] In such a modified example, even if the processing oil OL remains in the caulking part 7a, the processing oil is likely to extend according to the viscosity, and the thickness of the oil film between the concave part 7aa and the convex part 7ab can be reduced. As a result, an increase in the gap between the adjacent core pieces 7 can be suppressed. In addition, in this modified example as well, the same operational effects as those of the first embodiment can be achieved.

Embodiment

[0083] FIGS. 12(A) and (B) are schematic cross-sectional views showing an injection part used in the processing oil supply device according to Embodiment 3 of the present invention. FIG. 12(A) shows the non-injection state, and FIG. 12(B) shows the injection state. In addition, in Embodiment 3, since the basic configuration is common to that of the first embodiment, the corresponding configurations are denoted by the same reference numerals and redundant descriptions are omitted. Also, for the overall configuration of Embodiment 3, refer to FIG. 1.

[0084] In the processing oil supply device 11 of the present embodiment, the injection part 19 of the injection device 17 is an inkjet method. Other aspects are the same as those of the first embodiment.

[0085] That is, the injection unit 19 includes a hollow head portion 33 and a piezoelectric element 35. The head portion 33 has a storage portion 33a for storing the machining oil OL in the hollow interior. The storage portion 33a communicates with the injection port 33b of the machining oil OL, and supplies the machining oil OL to the injection port 33b by the operation of the piezoelectric element 35.

[0086] The piezoelectric element 35 is disposed so as to close the opening 33b provided in the head portion 33, and is disposed facing the storage portion 33a. When a voltage is applied to the piezoelectric element 35, it displaces into the storage portion 33a. Due to this displacement, the volume of the storage portion 33a decreases, and the surplus machining oil OL is supplied to the injection port 33b and injected.

[0087] Note that the injection unit 19 may be an inkjet system, and may use a heater or a solenoid in addition to the piezoelectric element 35.

[0088] In this embodiment, in addition to the effects of the first embodiment, the application amount of the machining oil OL can be easily adjusted.

Explanation of Reference Numerals

[0089] 1 Laminated core 5 Steel plate 5a Core piece portion 5b Crimping planned portion 5c Punching planned portion 7 Core piece 7a Crimping portion 7c Inner circumference (punching portion) 7d Outer circumference (punching portion) 7e Magnet insertion hole (punching portion) 11 Machining oil supply device 17 Injection device 19 Injection unit 19a First injection unit 19b Second injection unit OL Machining oil

Claims

1. A method for supplying machining oil when forming a core piece having a caulking portion with one side being a concave portion and the other side being a convex portion and a punching portion formed by punching from a steel sheet, comprising: injecting the machining oil onto a caulking planned portion that will become the caulking portion of the steel sheet and a punching planned portion that will become the punching portion; varying at least one of the injection amount and viscosity of the machining oil between the caulking planned portion and the punching planned portion, and in the case of the injection amount of the machining oil, varying it so as to be relatively less at the caulking planned portion, and in the case of the viscosity of the machining oil, varying it so as to be relatively lower at the caulking planned portion; A machining oil supply method.

2. The machining oil supply method according to Claim 1, comprising: selectively injecting the machining oil from a plurality of injection parts; setting the injection amount of the machining oil according to the number of the injection parts. A machining oil supply method.

3. The machining oil supply method according to Claim 1, comprising: performing the injection of the machining oil while feeding the steel sheet with a plurality of first injection parts arranged in a row along the width direction of the steel sheet and a plurality of second injection parts arranged in a row along the width direction of the steel sheet being shifted in the feeding direction and the width direction of the steel sheet. A machining oil supply method.

4. The machining oil supply method according to Claim 1, comprising: injecting the machining oil from a plurality of first injection parts arranged in a row along the width direction of the steel sheet and a plurality of second injection parts arranged in a row along the width direction of the steel sheet onto the caulking planned portion and the punching planned portion respectively while feeding the steel sheet. A machining oil supply method.

5. The machining oil supply method according to Claim 1, comprising: injecting the machining oil onto the front and back surfaces of the caulking planned portion and the punching planned portion. A machining oil supply method.

6. A machining oil supply device for supplying machining oil when forming a core piece having a caulking portion with one side being a concave portion and the other side being a convex portion and a punching portion formed by punching from a steel sheet, comprising: an injection device for injecting the machining oil onto a caulking planned portion that will become the caulking portion of the steel sheet and a punching planned portion that will become the punching portion; the injection device varies at least one of the injection amount and viscosity of the machining oil between the caulking planned portion and the punching planned portion, and in the case of the injection amount of the machining oil, varies it so as to be relatively less at the caulking planned portion, and in the case of the viscosity of the machining oil, varies it so as to be relatively lower at the caulking planned portion; A machining oil supply device.

7. The machining oil supply device according to Claim 6, comprising: the injection device includes a plurality of injection parts for selectively injecting the machining oil. Set the injection amount of the processing oil according to the number of the injection parts. Processing oil supply device.

8. The processing oil supply device according to Claim 6, The injection of the processing oil is performed while feeding the steel sheet, The injection device includes a plurality of first injection parts arranged in a row along the width direction of the steel sheet, and a plurality of second injection parts arranged in a row along the width direction, which are shifted in the feeding direction and the width direction of the steel sheet with respect to the first injection parts. Processing oil supply device.

9. The processing oil supply device according to Claim 6, The injection of the processing oil is performed while feeding the steel sheet, The injection device includes a plurality of first injection parts arranged in a row along the width direction of the steel sheet, and a plurality of second injection parts arranged in a row along the width direction. The first injection parts and the second injection parts inject the processing oil into the caulking planned part and the punching planned part respectively. Processing oil supply device.

10. The processing oil supply device according to any one of Claims 6 to 9, The injection device injects the processing oil by an inkjet method. Processing oil supply device.

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