JP7630779B2 - Annular laminated core material and manufacturing method thereof - Google Patents

Description

The present invention relates to an annular laminated core material and a method for manufacturing an annular laminated core material.

Conventionally, annular laminated core materials such as motor cores are known, which are formed by joining a predetermined number of annular core materials punched out from a strip-shaped thin plate material in a stacked state. For example, an automatic lamination method is known as a method for manufacturing annular laminated core materials. In the automatic lamination method, first, the strip-shaped thin plate material is intermittently transferred by a progressive die device, and the desired die-cutting process is sequentially performed on the thin plate parts for the core material of the strip-shaped thin plate material. Next, the thin plate parts for the core material are punched out with an outer diameter punch, separated from the strip-shaped thin plate material, and punched out sequentially into the die. Then, the punched-out core materials are joined in a stacked state in a predetermined number of sheets by a crimping joining means, which is a type of temporary fixing means previously provided on the core material.

In the in-mold automatic stacking method, typical crimping means include, for example, providing each core material with a cut-and-raised portion in advance, as in Patent Document 1 (JP Patent Publication No. 58-116033), or providing a embossed protrusion (dowel) as in Patent Document 2 (JP Patent Publication No. 49-37103), and crimping each adjacent core material vertically in the stacked state using the cut-and-raised portion or embossed protrusion.

Laminated core materials are also known, in which each core material is bonded together using, for example, an adhesive or a laser beam.

Japanese Unexamined Patent Publication No. 58-116033 Japanese Unexamined Patent Publication No. 49-37103

However, with the above crimping connection method, the connection parts such as the cut and raised parts and the protrusions remain as they are even when the motor is assembled, which causes problems such as eddy currents to occur in the crimped connection parts, resulting in a few percent decrease in efficiency due to iron loss.

In addition, in the method of bonding using a direct-connect material or a laser beam, after the adhesive application or laser beam irradiation process, an additional process of fitting the resin molded body into the laminated core material was required to ensure electrical insulation with the windings.

The present invention aims to provide an annular laminated core material that eliminates iron loss caused by eddy currents generated at the joints between the core materials and does not require additional processes, as well as a manufacturing method for the same.

The present invention is an annular laminated core material, characterized in that it comprises a core body formed by stacking a plurality of annular core materials into a cylindrical shape, with an axially extending groove formed on the radially inner inner circumferential surface or the radially outer outer circumferential surface, a pair of body parts formed to cover at least a portion of both axial end surfaces of the core body, a resin molded body integrally molded with a connecting part connecting the pair of body parts, and an insulating sheet disposed on the inner surface of the groove, and both axial end portions of the insulating sheet are in contact with the body parts of the resin molded body, respectively.

According to the present invention having the above configuration, a pair of main body parts of the resin molded body are integrated by the connecting part, and further, the insulating sheet and the resin molded body are connected by abutting each other, so that the laminated core material can be integrated without temporary fixing by crimping or adhesive. This makes it unnecessary to provide a crimping joint for crimping the core material, suppressing iron loss, and does not require additional processes such as applying adhesive or using a laser beam.

In the present invention, the core body is preferably formed with a through hole extending between both end faces in the axial direction, and the connecting portion passes through the through hole of the core body to connect the pair of body portions.
According to the present invention having the above-mentioned configuration, when the resin molded body is molded, the molten resin passes through the through hole and fills the space corresponding to the pair of main body portions and the connecting portion, thereby making it possible to integrate the main body portion and the connecting portion.

In the present invention, a groove is preferably formed on the inner or outer peripheral surface of the core body, extending between both axial end faces, and the connecting portion passes through the groove of the core body to connect the pair of body portions.
According to the present invention having the above-mentioned configuration, when the resin molded body is molded, the molten resin passes through the circumferential groove portion and fills the space corresponding to the pair of main body portions and the connecting portion, thereby making it possible to integrate the main body portion and the connecting portion.

In the present invention, preferably, both axial surfaces of the annular core material are flat, and the flat surfaces of each core material are in direct contact with the flat surfaces of the adjacent core material.
According to the present invention having the above configuration, iron loss can be further suppressed.

In the present invention, the insulating sheet and the resin molded body are preferably connected without using an adhesive.
According to the present invention having the above configuration, an annular laminated core material can be manufactured without performing an additional step such as bonding.

In the present invention, the axial length of the contact portion between the insulating sheet and the resin molded body is preferably 0.5 mm or more.
According to the present invention having the above configuration, if the axial length of the contact portion between the insulating sheet and the resin molded body is 0.5 mm or more, when linear segment conductors are arranged in the grooves of the annular laminated core material 1 and the core materials are bent, there will be no misalignment between the core materials and the core materials will be able to withstand the load applied when bent.

In the present invention, the insulating sheet and the resin molded body are preferably connected by impregnating the surface of the insulating sheet that comes into contact with the resin molded body with the resin that constitutes the resin molded body.
According to the present invention having the above configuration, the insulating sheet and the resin molded body can be more firmly connected to each other.

In the present invention, the resin molded body is preferably formed using a polymer having an amide bond, and the surface of the insulating sheet in contact with the resin molded body is preferably composed of a polymer having an amide bond.
According to the present invention having the above configuration, the polymer and the insulating sheet are entangled at the molecular level, and the insulating sheet and the resin molded body can be more firmly connected to each other.

In the present invention, preferably, the resin molded body is formed using a polymer having an amide bond, and the surface of the insulating sheet that contacts the resin molded body is composed of aramid paper made of aramid fibrids and aramid short fibers.
According to the present invention having the above configuration, the polymer and the insulating sheet are entangled at the molecular level, and the insulating sheet and the resin molded body can be more firmly connected to each other.

The motor of the present invention uses a stator in which a winding is wound around the above-mentioned annular laminated core material.
According to the motor having the above configuration, the above-mentioned operational effects are achieved.

The motor generator of the present invention uses a stator in which a winding is wound around the above-mentioned annular laminated core material.
According to the motor generator configured as above, the above-mentioned operational effects are achieved.

The generator of the present invention uses a stator having a winding wound around an annular laminated core material.
According to the generator having the above configuration, the above-mentioned operational effects are achieved.

The present invention is a method for manufacturing an annular laminated core material, which includes a step of placing a core body formed by stacking a plurality of annular core blocks into a cylindrical shape and having an axially extending groove formed on the radially inner inner surface or the radially outer outer surface in a molding die so that an insulating sheet is placed in the groove, and a resin molding step of injecting resin into the molding die to integrally mold a resin molded body including a pair of body parts formed to cover at least a portion of both axial end surfaces of the core body, and a connecting part connecting the pair of body parts.

According to the present invention configured as above, the main body and the connecting portion can be integrally formed, and the laminated core material can be integrated without temporary fixing by crimping or gluing.

The present invention provides an annular laminated core material that eliminates iron loss caused by eddy currents generated at the joints between the core materials and does not require additional processes, and a manufacturing method for the same.

FIG. 1 is a schematic perspective view showing a configuration of an annular laminated core material according to one embodiment of the present invention. FIG. 2 is a perspective view showing a core body of the annular laminated core material shown in FIG. 1 . FIG. 3 is a perspective view showing a core material constituting the core body shown in FIG. 2 . FIG. 2 is a perspective view showing an insulating sheet of the annular laminated core material shown in FIG. 1 . FIG. 11 is a perspective view showing a core body of an annular laminated core material according to another embodiment.

The following describes an annular laminated core material and a method for manufacturing the same according to one embodiment of the present invention, with reference to the drawings, but the present invention is not limited thereto.

(Annular laminated core material)
Fig. 1 is a schematic perspective view showing the configuration of an annular laminated core material according to one embodiment of the present invention. As shown in Fig. 1, the annular laminated core material is cylindrical, has a plurality of arms extending radially inward on its inner peripheral surface, and has a shape in which grooves are formed between the arms. In the annular laminated core material 1, the axial length of the contact portion between the insulating sheet and the resin molded body is preferably 0.5 mm or more. The annular laminated core material according to this embodiment is used as a stator for a motor, a motor generator, or a generator, for example, by winding a winding around each arm.

(Core body)
Fig. 2 is a perspective view showing the core body of the annular laminated core material shown in Fig. 1. As shown in Fig. 2, the core body 4 is a cylindrical member formed by laminating a plurality of annular core materials 8, and is formed so that a plurality of openings on the inner peripheral surface extend in the axial direction. Note that although the boundaries of the laminated core materials 8 forming the core body 4 are not necessarily visible, they are shown in Figs. 1, 2 and 5 for the purpose of explanation.

Figure 3 is a perspective view showing the core material constituting the core body shown in Figure 2. As shown in Figure 3, the core material 8 is a plate-shaped member formed with flat surfaces on both axial sides, and has a cross section in which the radially outer peripheral portion of the approximately H-shaped portion is connected in a circular shape. The core material 8 has an annular ring portion 8a, a plurality of arms 8b extending circumferentially inward from the annular portion 8a, and protrusions 8c extending circumferentially on both sides from the tip of the arms 8b. Between each arm portion 8b, a groove portion 8d having a substantially trapezoidal shape is formed, surrounded by the adjacent arms 8b, the annular portion 8a, and the protrusions 8c. In addition, six peripheral groove portions 8e are formed at equal angular intervals in the circumferential direction on the outer peripheral surface of the annular portion 8a. Metals such as silicon steel plate can be used as the material of the core material 8.

As shown in FIG. 2, the core body 4 is formed by stacking multiple core materials 8 without any temporary fixing means. That is, the surface of each core material 8 does not have any cut-and-raised portion or embossed protrusion for crimping. In addition, the flat surfaces of the core materials 8 adjacent in the axial direction are directly in contact with each other, and there is no adhesive between the core materials 8, and there are no welding marks by the laser beam. The core body 4 has the same cross-sectional shape over its entire axial length, and includes a cylindrical cylindrical portion 4a, multiple arm portions 4b extending circumferentially inward from the cylindrical portion 4a, and protruding portions 4c extending circumferentially on both sides from the tips of the arm portions 4b. The axial thickness of the core body 4 is equal to the thickness of the annular laminated core material 1 excluding the pair of main body portions 2a of the resin molded body 2 from the axial direction. The cylindrical portion 4a of the core body 4 is formed by laminating the annular portion 8a of the core material 8, the arm portion 4b of the core body 4 is formed by laminating the arm portion 8b of the core material 8, and the protruding portion 4c of the core body 4 is formed by laminating the protruding portion 8c of the core material 8.

Between each arm 4b, a roughly trapezoidal groove 4d is formed that is surrounded by the adjacent arm 4b, the cylindrical portion 4a, and the protruding portion 4c and extends in the axial direction. The groove 4d of the core body 4 is formed by the grooves 8d of the laminated core materials 8 continuing in the axial direction. In addition, six outer peripheral grooves 4e are formed on the outer peripheral surface of the cylindrical portion 4a at equal angular intervals in the circumferential direction and extending in the axial direction. The outer peripheral grooves 4e of the core body 4 are formed by laminating the outer peripheral grooves 8e of multiple core materials 8.

In this embodiment, the outer peripheral groove 4e is formed on the outer peripheral surface of the core body 4, and the connecting portion 2b is formed in the outer peripheral groove 4e. However, this is not limited to the above, and for example, as shown in FIG. 5, a through hole 104b penetrating the core body 104 in the axial direction may be formed. In this case, the outer peripheral groove 4e is not necessary. When the core body 104 having such a configuration is used, a connecting portion is formed in the through hole 104b, and the main body portions 2a can be connected to each other through the through hole 104b. When forming such a through hole, it is preferable to form it in the cylindrical portion 104a. Also, in this embodiment, the groove portion 4d is formed on the inner peripheral surface of the core body 4 on the radial inner side, but a groove may be formed on the outer peripheral surface of the core body 4 on the radial outer side. In this case, instead of the outer peripheral groove 4e, an inner peripheral groove extending in the axial direction may be formed on the inner peripheral surface of the radial inner side, and a connecting portion of the resin molded body may be formed in this inner peripheral groove, or a through hole may be formed in the cylindrical portion, and a connecting portion of the resin molded body may be formed in this through hole.

(insulating sheet)
4 is a perspective view showing an insulating sheet of the annular laminated core material shown in FIG. 1. As shown in FIG. 4, the insulating sheet 6 has a substantially U-shaped cross section in the axial direction and has the same axial length as the annular laminated core material 1. The insulating sheet 6 is formed by folding a long strip-shaped sheet material, and has a central portion 6a, a left bent portion 6b, and a right bent portion 6c. The central portion 6a has a width equal to the width of the bottom of the groove portion 4d of the core body 4. The left bent portion 6b and the right bent portion 6c have a width equal to the surface extending in the radial direction of the groove portion 4d of the core body 4. The radial inner end edges of the left bent portion 6b and the right bent portion 6c are bent toward each other to form tip bent portions 6d and 6e.

As shown in FIG. 1, the insulating sheet 6 is disposed on the inner surface of each groove 4d of the core body 4. The central portion 6a of the insulating sheet 6 is disposed on the bottom (radially outer surface) of the groove 4d, and the left bent portion 6b and the right bent portion 6c are disposed on the surface extending in the radial direction of the groove 4d. The tip bent portions 6d and 6e are disposed on the radially outer surface of the protruding portion 8c. In addition, both axial ends of the insulating sheet 6 protrude outward from both axial end surfaces of the core body 4 by a length equal to the thickness of the main body portion 2a of the resin molded body 2. The insulating sheet 6 is provided to insulate between the windings of the motor and the inner peripheral surface of the groove portion 4d of the core body 4 when the windings are wound around the arm portion 4b of the core body 4.

In this embodiment, insulating paper, nonwoven fabric, film, or a composite or laminated sheet thereof can be used as the insulating sheet. Examples include insulating paper such as aramid paper made of aramid fibrids and aramid short fibers, plastic films such as polyphenylene sulfide film, polyimide film, polyether ether ketone film, polyethylene terephthalate film, and polyethylene naphthalate film, and laminated sheets thereof. In particular, a laminated sheet containing aramid paper made of aramid fibrids and aramid short fibers on at least one side is preferred. Here, as the adhesive used to laminate the aramid paper, a suitable adhesive commonly used in the technical field can be used, and examples include, but are not limited to, adhesives such as epoxies, acrylics, phenols, polyurethanes, silicones, polyesters, and amides. In addition, when the above-mentioned film is laminated with an adhesive, the film is usually stretched in many cases, and when a motor bobbin is manufactured by the melt injection molding method of the present invention described later, deformation of the laminated sheet due to shrinkage is likely to occur. For this reason, laminated sheets in which the polymer is melt-formed into a film and the above-mentioned aramid paper are layered and heated and pressurized to melt-impregnate the polymer into the aramid paper, laminated sheets in which a polymer paper product (web) and aramid paper are combined or layered and heated and pressurized to melt-impregnate the resin into the aramid paper, and laminated sheets in which resin is melt-extruded onto the aramid paper and heat-fused are preferably used.

The number of layers of the laminated sheet can be appropriately selected depending on the application and purpose of the laminate. Examples include, but are not limited to, a two-layer laminated sheet of polymer and aramid paper, which is made of an aromatic polyamide resin produced by melt-extruding and heat-fusing resin onto aramid paper as described in JP-A-2006-321183 and an epoxy-containing phenoxy resin having an epoxy group in the molecule, and in which the ratio of the epoxy-containing phenoxy resin is 30 to 50 mass %, and a three-layer laminated sheet of aramid paper, polymer, and aramid paper.

If the adhesion between the insulating sheet and the resin molded body described below is insufficient and peels off when winding the wire, it is preferable to surface treat the surface of the insulating sheet that comes into contact with the resin molded body to improve adhesion. Examples of surface treatment include plasma surface treatment, corona surface treatment, and surface treatment by immersion in liquid. By carrying out such surface treatments, the surface energy of the insulating paper surface is improved and the interfacial energy with the resin molded body is reduced, resulting in improved adhesion with the resin molded body. Plasma surface treatment is particularly preferred due to its ease of treatment.

The thickness of the insulating sheet can be appropriately selected depending on the application and purpose of the insulating sheet, and any thickness can be selected as long as there are no problems with workability such as bending and wrapping. In general, from the viewpoint of workability, a thickness in the range of 50 μm to 1000 μm (particularly preferably 70 to 200 μm) is preferable, but is not limited to this.

(Aramid)
In this embodiment, aramid means a linear polymeric compound (aromatic polyamide) in which 60% or more of amide bonds are directly bonded to an aromatic ring. Examples of such aramids include polymetaphenylene isophthalamide and its copolymers, polyparaphenylene terephthalamide and its copolymers, and poly(paraphenylene)-copoly(3,4'-diphenyl ether) terephthalamide. These aramids are industrially produced by conventionally known interfacial polymerization methods, solution polymerization methods, etc. using isophthalic acid chloride and metaphenylenediamine, and are available as commercial products, but are not limited thereto. Among these aramids, polymetaphenylene isophthalamide is preferably used because it has good moldability, heat adhesion, flame retardancy, heat resistance, and other properties.

(Aramid Fibre)
In this embodiment, the aramid fibrids are film-like aramid particles having papermaking properties, and are also called aramid pulp (see JP-B-35-11851, JP-B-37-5732, etc.).

It is widely known that aramid fibrids are used as a papermaking raw material after being defibrated and beaten in the same manner as ordinary wood pulp, and so-called beating can be performed in order to maintain the quality suitable for papermaking. This beating can be performed by a disc refiner, beater, or other papermaking raw material processing equipment that exerts a mechanical cutting action. In this operation, the morphological change of the fibrids can be monitored by the freeness test method (freeness) specified in Japanese Industrial Standard P8121. In this embodiment, the freeness of the aramid fibrids after beating is preferably within the range of 10 cm ³ to 300 cm ³ (Canadian freeness (JIS P8121)). Fibrids with a freeness greater than this range may have a reduced strength of the aramid paper formed therefrom. On the other hand, if you try to obtain a freeness of less than 10 ^cm3 , the efficiency of using the mechanical power you put in will be low, and the amount of processing per unit time will often be small, and the fibrids will be too fine, which will tend to cause a decrease in the so-called binder function. Therefore, even if you try to obtain a freeness of less than 10 ^cm3 in this way, there is no significant advantage.

(Aramid short fiber)
Aramid short fibers are cut fibers made of aramid. Examples of such fibers include those available under the trade names "Teijinconex (registered trademark)" from Teijin Limited and "Nomex (registered trademark)" from DuPont, but are not limited to these.

The length of the aramid short fibers can generally be selected from the range of 1 mm or more and less than 50 mm, preferably 2 to 10 mm. If the length of the short fibers is less than 1 mm, the mechanical properties of the sheet material will decrease, while if the length is 50 mm or more, tangling and bundling will easily occur during the wet process of producing aramid paper, which can easily cause defects.

(Aramid paper)
In this embodiment, the aramid paper is a sheet-like material mainly composed of the above-mentioned aramid fibrids and aramid short fibers, and generally has a thickness within a range of 20 μm to 1000 μm, preferably 25 to 200 μm. Furthermore, the aramid paper generally has a basis weight within a range of 10 g/m ² to 1000 g/m ² , preferably 15 to 200 g/m ^2. Here, the mixing ratio of the aramid fibrids and the aramid short fibers can be any ratio, but the ratio (mass ratio) of the aramid fibrids/aramid short fibers is preferably 1/9 to 9/1, more preferably 2/8 to 8/2, and particularly 3/7 to 7/3, but is not limited to this range.

Aramid paper is generally produced by mixing the above-mentioned aramid fibrids and aramid short fibers and then forming them into a sheet. Specifically, for example, a method of dry-blending the above-mentioned aramid fibrids and aramid short fibers and then forming a sheet using an air flow, or a method of dispersing and mixing the aramid fibrids and aramid short fibers in a liquid medium, discharging them onto a liquid-permeable support such as a net or belt to form a sheet, and then removing the liquid and drying them, can be applied. Among these, the so-called wet papermaking method, which uses water as the medium, is preferably selected.

In the wet papermaking method, a single or mixed aqueous slurry containing at least aramid fibrids and aramid short fibers is generally fed to a papermaking machine, dispersed, and then dehydrated, squeezed, and dried, before being wound into a sheet. Papermaking machines that can be used include Fourdrinier papermaking machines, cylinder papermaking machines, tilted papermaking machines, and combination papermaking machines that combine these. When using a combination papermaking machine, slurries with different blending ratios are formed into sheets and combined to obtain a composite sheet consisting of multiple paper layers. Additives such as dispersibility improvers, defoamers, and paper strength enhancers are used as necessary during papermaking.

The density and mechanical strength of the aramid paper obtained as described above can be improved by hot pressing between a pair of rolls at high temperature and pressure. When using metal rolls, the hot pressing conditions can be, for example, in the range of a temperature of 100 to 400°C and a linear pressure of 50 to 400 kg/cm, but are not limited to these. Multiple pieces of aramid paper can be stacked during hot pressing. The above hot pressing process can also be carried out multiple times in any order.

(Resin molded body)
The resin molded body 2 includes a pair of main body parts 2a formed along both axial end faces of the core body 4, and six connecting parts 2b connecting the edges of the outer periphery of the pair of main body parts 2a. The main body part 2a has a thickness equivalent to the distance between the axial end face of the core body 4 and the end of the insulating sheet 6, and has the same cross-sectional shape as the core body 4 (core material 8). That is, the main body part 2a includes an annular ring part 2a1, a plurality of arm parts 2a2 extending circumferentially inward from the annular ring part 2a1, and a protrusion part 2a3 extending circumferentially on both sides from the tip part of the arm part 2a2. Between each arm part 2a2, a groove part 2a4 having a substantially trapezoidal shape is formed, which is surrounded by the adjacent arm part 2a2, the annular part 2a1, and the protrusion part 2a3. The bottom of the groove 2a4 is in contact with the radial outer peripheral surface of the central portion 6a of the insulating sheet 6, the left bent portion 6b and the right bent portion 6c of the insulating sheet 6 are in contact with the side surface of the arm portion 2a2, and the tip bent portions 6d and 6e of the insulating sheet 6 are in contact with the radial outer peripheral surface of the protruding portion 2a3. The main body portion 2a of the resin molded body 2 is provided to insulate between the winding and the upper surface of the arm portion 4b of the core body 4 when the winding of the motor is wound around the arm portion 4b of the core body 4. In this embodiment, the main body portion 2a is formed to cover the entire axial end surface of the core body 4, but it is sufficient that the main body portion 2a is in contact with at least the axial end portion of the insulating sheet 6 and covers the arm portion 4b of the core body 4 on which the winding of the motor is arranged. The resin constituting the resin molded body 2 is impregnated into the surface of the insulating sheet 6 that is in contact with the resin molded body 2, thereby connecting the resin molded body 2 and the insulating sheet 6. In this embodiment, the outer circumferential surfaces of the portions of the insulating sheet 6 that protrude from the core body 4 at both ends are in contact with the molded resin body 2 .

The connecting portions 2b are formed in the outer peripheral grooves 4e of the core body 4 and connect the pair of body portions 2a through the outer peripheral grooves 4e. The connecting portions 2b are provided at equal angular intervals on the outer peripheral surface of the core body 4.

In this embodiment, the material constituting the resin molded body 2 may be, for example, PPS resin (polyphenylene sulfide resin), acrylonitrile-butadiene-styrene copolymer resin, polyimide resin, polyethylene terephthalate resin, polyacetal resin, polymers containing amide bonds such as polyamide 6, polyamide 66, polyamide 612, polyamide 11, polyamide 12, copolymer polyamide, polyamide MXD6, polyamide 46, methoxymethylated polyamide, and semi-aromatic polyamide, or a polymer containing a polyamide resin composition as shown in JP-A-2006-321951, or a mixture thereof, or a mixture of the above polymer and an inorganic substance such as glass fiber. The resin molded body 2 is produced by a melt injection molding method in which the above material is injected (injected) in a molten state into a desired mold and then removed from the mold after cooling. In particular, a molded body of a mixture of semi-aromatic polyamide and glass fiber is preferable because it has high heat resistance and good adhesion to a laminated sheet including aramid paper. Examples of such mixtures include, but are not limited to, DuPont's Zytel (registered trademark) HTN51G and 52G.

By forming a groove for positioning the winding in the part of the resin molded body 2 that comes into contact with the winding, the position of the winding is stabilized, enabling highly accurate aligned winding, which is preferable because it improves the efficiency of motor generators, etc.

(Method of manufacturing annular laminated core material)
The annular laminated core material 1 of this embodiment can be manufactured as follows.
That is, first, a desired die-cutting process is performed on a strip-shaped thin plate material, and then the core material is separated by punching with an outer diameter punch. The punched core material 8 is then stacked in a cylindrical cavity of an injection molding die to form the core body 4. Note that the core material 8 does not have a cut-and-raised portion or a embossed protrusion for riveting, and the core material 8 is not bonded by an adhesive or a laser beam, and each core material 8 has no trace of a temporary fixing means. Next, an insulating sheet 6 is placed in the groove 4d of the core body 4. At this time, the insulating sheet 6 is placed so that both ends of the insulating sheet 6 protrude from both end faces of the core body 4 by a length equivalent to the thickness of the main body 2a of the resin molded body 2 (placement step). At this time, the distance between both axial end faces of the core body 4 and the inner surface of the cavity is the same as the protruding length of the insulating sheet 6, and the core body 4 is placed so that the inner and outer circumferential surfaces are in contact with the inner surface of the cavity. As a result, spaces corresponding to the main body portion 2a of the resin molded body 2 are formed between both end faces of the core body 4 and the inner surface of the cavity, and a space corresponding to the connecting portion 2b extending in the axial direction is formed between the outer circumferential groove portion 4e of the core body 4 and the inner circumferential surface of the cavity. Note that in this embodiment, the insulating sheet 6 is attached after the core body 4 is formed by stacking the core material 8 in the cavity, but this is not limiting, and the core body 4 with the insulating sheet 6 attached may be placed in the cavity.

Next, the resin that constitutes the resin molded body 2 is injected into the cavity, filling the space between the core body 4 and the inner surface of the cavity. Then, as the resin hardens, the resin molded body 2 is molded, with the main body portion 2a and the connecting portion 2b integrated together (resin molding step). Through the above steps, the core material 8 that constitutes the laminated core body 4 is fixed by the resin molded body 2 and the insulating sheet 6, and an integrated annular laminated core material 1 can be manufactured.

In the manufacturing method of this embodiment, a plurality of core materials 8 are laminated in an injection molding cavity without any trace of a temporary fixing means between each core material 8, and an insulating sheet 6 is arranged in advance so that at least a portion of the insulating sheet 6 is in contact with the portion corresponding to the resin molded body 2, so that the molten polymer forming the resin molded body 2 can be impregnated into at least the surface portion of the insulating sheet 6. By producing an annular laminated core material 1 in which a portion of the resin molded body 2 and the insulating sheet 6 are connected and fixed in this manner, there is no need to use an adhesive, and the insulating sheet 6 can be connected and fixed at the same time when the resin molded body is produced. Here, impregnation means that the molten polymer penetrates the surface of the insulating sheet. In particular, when the insulating sheet contains a polymer having an amide bond and/or aramid paper, the molten polymer penetrates the surface of the polymer having an amide bond and/or the aramid fibrid and/or aramid short fiber that constitute the aramid paper. By impregnation, the polymer and the insulating sheet 6 are entangled at the molecular level, and the adhesion between the resin molded body 2 and the insulating sheet 6 becomes stronger. In addition, the expansion of the resin and core material 8 due to temperature changes during molding improves adhesion between the insulating sheet 6 and the core material 8, so heat generated by the windings is efficiently transferred to the core material 8, preventing excessive temperature increases, reducing copper loss in the windings, and improving motor output.

In particular, when the resin molded body 2 is formed using a polymer having an amide bond and the surface of the insulating sheet 6 that is in contact with the resin molded body 2 is made of a polymer having an amide bond, or when the resin molded body 2 is formed using a polymer having an amide bond and the surface of the insulating sheet 6 that is in contact with the resin molded body 2 is made of aramid paper made of aramid fibrids and aramid short fibers, the polymer having an amide bond that constitutes the resin molded body 2 and the insulating sheet 6 become entangled at the molecular level, and the adhesion between the resin molded body 2 and the insulating sheet 6 becomes stronger.

(Action and Effect)
According to this embodiment, the following advantageous effects are achieved.
According to this embodiment, the pair of main body portions 2a of the resin molded body 2 are integrated by the connecting portion 2b, and further, the insulating sheet 6 and the resin molded body 2 are connected by abutting against each other, so that the laminated core material 8 can be integrated without temporary fixing by crimping, adhesion, etc. This makes it unnecessary to provide a crimping joint portion for crimping in the core material 8, thereby suppressing iron loss, and does not require additional processes such as applying an adhesive or using a laser beam.

In addition, according to this embodiment, when the resin molded body 2 is molded, the molten resin passes through the outer peripheral groove 4e, the inner peripheral groove, or the through hole and fills the space corresponding to the pair of main body parts 2a and connecting part 2b, so that the main body part 2a and connecting part 2b can be integrated.

In addition, according to this embodiment, both axial surfaces of the annular core material 8 are flat, and the flat surfaces of each core material 8 are in direct contact with the adjacent core material 8, which further suppresses iron loss.

In addition, in this embodiment, the insulating sheet 6 and the resin molded body 2 are connected without using adhesive, so the annular laminated core material 1 can be manufactured without performing additional processes such as bonding.

In addition, in this embodiment, the axial length of the contact area between the insulating sheet 6 and the resin molded body 2 is 0.5 mm or more, so that when linear segment conductors are placed in the grooves of the annular laminated core material 1 and the core materials are bent, there is no misalignment between them and the material can withstand the load applied when bent.

In addition, in this embodiment, the surface of the insulating sheet 6 that contacts the resin molded body 2 is impregnated with the resin that constitutes the resin molded body 2, thereby connecting the insulating sheet 6 and the resin molded body 2, so that the insulating sheet 6 and the resin molded body 2 can be connected more firmly.

In addition, in this embodiment, the resin molded body 2 is formed using a polymer having an amide bond, and the surface of the insulating sheet 6 that contacts the resin molded body 2 is made of a polymer having an amide bond, so that the polymer and the insulating sheet 6 become entangled at the molecular level, and the insulating sheet 6 and the resin molded body 2 can be more firmly connected.

In addition, in this embodiment, the resin molded body 2 is formed using a polymer having an amide bond, and the surface of the insulating sheet 6 that contacts the resin molded body 2 is made of aramid paper made of aramid fibrids and aramid short fibers, so that the polymer and the insulating sheet 6 are entangled at the molecular level, and the insulating sheet 6 and the resin molded body 2 can be more firmly connected.

The present invention will be described below with reference to examples. Note that these examples are provided to illustrate the content of the present invention and are not intended to limit the content of the present invention in any way.

(Raw material preparation)
Using a pulp particle manufacturing device (wet precipitator) consisting of a combination of a stator and a rotor, described in JP-A-52-15621, polymetaphenylene isophthalamide fibrids were manufactured. This was treated with a disintegrator and a beater to adjust the length-weighted average fiber length to 0.9 mm. The freeness of the obtained aramid fibrids was 90 ^cm3 .

Meanwhile, meta-aramid fiber (Nomex (registered trademark), single filament fineness 2 denier) manufactured by DuPont was cut to a length of 6 mm (hereinafter referred to as "aramid short fiber").

(Aramid paper manufacturing)
The prepared aramid fibrids and aramid short fibers were dispersed in water to prepare slurries. These slurries were mixed so that the fibrids and aramid short fibers were mixed in a 1/1 blend ratio (weight ratio), and a sheet-like material was prepared using a Tappy-type hand-sheeting machine (cross-sectional area 625 ^cm2 ). This was then subjected to heat and pressure processing using a metal calendar roll at a temperature of 330°C and a linear pressure of 300 kg/cm to obtain aramid papers shown in Examples 1 and 2 of Table 1.

(Manufacture of Laminated Sheet)
Using the method described in paragraph [0024] of JP 2006-321183 A and a semi-aromatic polyamide resin composition containing 50% by weight of epoxy group-containing phenoxy resin (Formulation Example 6 of JP 2006-321183 A), laminated sheets shown in Examples ³ and 4 in Table 1 were obtained, which contain aramid paper having a three-layer structure of aramid paper/resin composition/aramid paper (weight ratio of 37/54/37) with the aramid paper arranged on the outside.

In addition, aramid paper (basis weight 37 g/ ^m2 , thickness 51 μm, density 0.73 g/ ^cm3 ) and a polyethylene terephthalate film (S28#16, thickness 16 μm) manufactured by Toray Industries, Inc. were bonded together with an adhesive to obtain laminated sheets shown in Examples 5 and 6 in Table 1, which include aramid paper having a three-layer structure of aramid paper/polyethylene terephthalate film/aramid paper (weight ratio 37/54/37) with the aramid paper positioned on the outside.

(Manufacturing of core materials)
A non-oriented electrical steel sheet (thickness: 0.5 mm, thickness tolerance: 0.04 mm) specified in JIS C 2552 was punched into an annular shape to produce a core material 8, as shown in Fig. 2. Note that there is no evidence of temporary fixing means such as caulking or bonding on the core material 8.

(Manufacture of annular laminated core material)
Using the aramid paper or laminated sheet manufactured as described above as the insulating sheet, the core material 8 manufactured as described above, and semi-aromatic polyamide manufactured by DuPont (ZYTEL (registered trademark) HTN51G35EF) as the polymer, insertion molding was performed under the conditions shown in Table 1 to obtain an annular laminated core material 1 shown in FIG. 1. That is, (1) the core material 8 is laminated and inserted in advance into the cavity for injection molding, (2) an insulating sheet 6 is placed in the groove of the laminated core material 8, and (3) semi-aromatic polyamide manufactured by DuPont is introduced, and the resin molded body 2, the insulating sheet 6, and the laminated core material 8 are integrally molded by injection molding using a melt injection molding method. At this time, the molten polymer impregnates at least the surface portion of the insulating sheet 6, and the insulating sheet 6 is directly bonded to the surface of the resin molded body 2, so that an annular laminated core material 1 without any trace of the temporary fixing means shown in FIG. 1 can be obtained. The measurement methods for each condition are as follows.

(Measurement method)

(1) Measurement of basis weight and thickness: This was carried out in accordance with JIS C2300-2.

(2) Density calculation: Calculated by dividing basis weight by thickness.

(3) Tensile strength and tensile elongation were measured according to JIS C2300-2.

(4) Adhesion The adhesive portion between the insulating paper and the resin molding was visually observed. Those that had no wrinkles (bulges in the insulating paper) at the adhesive portion were judged as "good", and those that had wrinkles were judged as "poor".

(5) Appearance of Insulating Sheet 6 The degree of warping of the insulating sheet due to heat during molding was judged by visual inspection.

(6) Adhesion between insulating sheet 6 and core material 8 Regarding the degree of adhesion between the insulating sheet portion and core material 8, a motor bobbin containing core material 8 was impregnated with epoxy resin, hardened, and then cut perpendicular to the axial direction at the axial midpoint of the annular laminated core material 1 using a water jet containing garnet microparticles (Omax Model 626), and the average distance between the insulating sheet 6 and core material 8 at the cut surface was measured.

(7) Bending resistance Straight segment conductors were placed in the grooves of the annular laminated core material 1, and the core materials were visually observed for any misalignment when the material was bent. Those that had no misalignment were judged to be "good", and those that had misalignment were judged to be "poor".

From the results in Table 1, the annular laminated core material of the embodiment can withstand the load applied when the segment conductor is bent when the segment conductor is used for the winding because the outer peripheral surface is supported by the resin molded body. In addition, there is no trace of a temporary fixing means, and iron loss does not occur due to eddy currents generated by the remains of the crimped joint, and the grooves of the core material are covered with a thin insulating sheet, so that high efficiency can be expected by increasing the thickness of the winding. In addition, the adhesion between the insulating paper and the resin is sufficient, so the insulation breakdown voltage is sufficiently high, and furthermore, since the aramid paper and polymer used have high heat resistance, it is considered that the material can withstand heat generation from the winding, so that the material is useful as a motor bobbin that can withstand high efficiency and high output of motor generators, etc. In particular, in the case of the third and fourth embodiments, the resin composition of the middle layer of the laminated sheet has a structure similar to that of the resin molded body, so it is considered that the resin composition softened during molding, and the adhesion between the insulating sheet and the core material was the best.
Furthermore, compared to the case of JP 55-13665, in which the entire unnecessary removed thin plate portion is cut into a half-punched shape to form a crimped joint portion for temporary fastening, and this removed thin plate portion is then removed later by press punching, this method does not require a large punching force and can be easily removed, and no residual material or burrs are produced, so no post-processing is required, making it possible to manufacture high-quality laminated core material products with good workability.
Furthermore, since the resin molded body and the insulating sheet are attached at the same time as molding, the steps of crimping and attaching the resin molded body can be omitted.

1 Annular laminated core material 2 Resin molded body 2a Main body 2a1 Annular portion 2a2 Arm portion 2a3 Protrusion 2a4 Groove portion 2b Connection portion 4 Core main body 4a Cylindrical portion 4b Arm portion 4c Protrusion 4d Groove portion 4e Outer circumferential groove portion 6 Insulating sheet 6a Central portion 6b Left bent portion 6c Right bent portion 6d Tip bent portion 6e Tip bent portion 8 Core material 8a Annular portion 8b Arm portion 8c Protrusion 8d Groove portion 8e Outer circumferential groove portion

Claims (12)

An annular laminated core material,
a core body formed into a cylindrical shape by laminating a plurality of annular core materials, and having an axially extending groove formed on an inner peripheral surface on the radially inner side or an outer peripheral surface on the radially outer side;
a pair of body portions formed so as to cover at least a part of both axial end surfaces of the core body, and a connecting portion connecting the pair of body portions; and a resin molded body in which the pair of body portions are integrally molded.
an insulating sheet disposed on an inner surface of the groove,
Both axial end portions of the insulating sheet are in contact with the main body portion of the resin molded body,
The core body has a through hole extending between both axial end faces,
the connecting portion connects the pair of body portions through a through hole of the core body,
The groove portion is open to both axial end surfaces ,
The insulating sheet and the resin molded body are connected to each other by impregnating a surface of the insulating sheet that contacts the resin molded body with a resin that constitutes the resin molded body.
Annular laminated core material. An annular laminated core material,
a core body formed into a cylindrical shape by laminating a plurality of annular core materials, and having an axially extending groove formed on an inner peripheral surface on the radially inner side or an outer peripheral surface on the radially outer side;
a pair of body portions formed so as to cover at least a part of both axial end surfaces of the core body, and a connecting portion connecting the pair of body portions; and a resin molded body in which the pair of body portions are integrally molded.
an insulating sheet disposed on an inner surface of the groove,
Both axial end portions of the insulating sheet are in contact with the main body portion of the resin molded body,
a circumferential groove portion is formed on the inner circumferential surface or the outer circumferential surface of the core body, the circumferential groove portion extending between both end surfaces in the axial direction;
the connecting portion passes through the circumferential groove of the core body to connect the pair of body portions,
The groove portion is open to both axial end surfaces,
The insulating sheet and the resin molded body are connected to each other by impregnating a surface of the insulating sheet that contacts the resin molded body with a resin that constitutes the resin molded body.
Annular laminated core material. The annular core member has flat surfaces on both axial surfaces, and the flat surfaces of each core member are in direct contact with the adjacent core members.
3. An annular laminated core material according to claim 1 or 2. The annular laminated core material according to any one of claims 1 to 3, wherein the insulating sheet and the resin molded body are connected without using an adhesive. The annular laminated core material according to any one of claims 1 to 4, in which the axial length of the contact portion between the insulating sheet and the resin molded body is 0.5 mm or more. the resin molded body is formed using a polymer having an amide bond,
6. The annular laminated core material according to claim 1, wherein the surface of the insulating sheet that is in contact with the resin molded body is made of a polymer having an amide bond. the resin molded body is formed using a polymer having an amide bond,
The annular laminated core material according to any one of claims 1 to 5, wherein the surface of the insulating sheet that contacts the resin molded body is made of aramid paper made of aramid fibrids and aramid short fibers. A motor using a stator in which a winding is wound around the annular laminated core material described in any one of claims 1 to 7. A motor generator using a stator in which a winding is wound around the annular laminated core material described in any one of claims 1 to 7. A generator using a stator in which a winding is wound around the annular laminated core material described in any one of claims 1 to 7. A method for producing an annular laminated core material, comprising the steps of:
a placement step of placing the core body, which is formed into a cylindrical shape by stacking a plurality of annular core blocks and has an axially extending groove formed on an inner peripheral surface on the radially inner side or an outer peripheral surface on the radially outer side, in a molding die such that an insulating sheet is placed in the groove;
a resin molding step of injecting a resin into a mold to integrally mold a resin molded body including a pair of body portions formed so as to cover at least a part of both axial end surfaces of the core body,
The resin molded body is integrally formed with a pair of main body portions formed to cover at least a part of both axial end surfaces of the core body, and a connecting portion connecting the pair of main body portions,
The core body has a through hole extending between both axial end faces,
the connecting portion connects the pair of body portions through a through hole of the core body,
In the resin molding step, the insulating sheet is disposed so that at least a portion of the insulating sheet contacts the resin molded body, and the molten polymer forming the resin molded body is impregnated into at least a surface portion of the insulating sheet, and the resin molded body is formed so that the groove portion opens to both end surfaces in the axial direction.
A method for manufacturing an annular laminated core material. A method for producing an annular laminated core material, comprising the steps of:
a placement step of placing the core body, which is formed into a cylindrical shape by stacking a plurality of annular core blocks and has an axially extending groove formed on an inner peripheral surface on the radially inner side or an outer peripheral surface on the radially outer side, in a molding die such that an insulating sheet is placed in the groove;
a resin molding step of injecting a resin into a mold to integrally mold a resin molded body including a pair of body portions formed so as to cover at least a part of both axial end surfaces of the core body,
The resin molded body is integrally formed with a pair of main body portions formed to cover at least a part of both axial end surfaces of the core body, and a connecting portion connecting the pair of main body portions,
a circumferential groove portion is formed on the inner circumferential surface or the outer circumferential surface of the core body, the circumferential groove portion extending between both end surfaces in the axial direction;
the connecting portion passes through the circumferential groove of the core body to connect the pair of body portions,
In the resin molding step, the insulating sheet is disposed so that at least a portion of the insulating sheet contacts the resin molded body, and the molten polymer forming the resin molded body is impregnated into at least a surface portion of the insulating sheet, and the resin molded body is formed so that the groove portion opens to both end surfaces in the axial direction.
A method for manufacturing an annular laminated core material.

Images