JPS6260447A - Molding equipment for molded type stator - Google Patents

Abstract

PURPOSE:To position a molded type stator precisely by forming a slot in the axial direction of an intermediate indentation projecting section fitted to the inner diametral section of one stator core of stator-core molding dies, forward moving the projecting section of the other die into the intermediate indentation section and expanding the projecting section. CONSTITUTION:A stator core 21 is arranged in a molding space between a top force 27 and a bottom force 28 together with a coil 25. A plurality of slots 39 are formed in the axial direction to a fitting projecting section 38 where the bottom force 28 penetrates to the inner diametral section of the stator core 21. A projecting section 40 where the top force 27 intrudes to the inner diametral section of the stator core 21 and the intermediate indentation section of the fitting projecting section 38 are brought into contact in tapered surfaces. The fitting projecting section 38 is shaped to an intermediate die 33, and pushed toward the top force 27 by a spring 34. When the top force 27 and the bottom force 28 are clamped, the projecting section 40 for expansion is moved forward to the fitting projecting section 38 and expanded, and fixed to the stator core 21. A resin 37 is injected from a gate 35. Accordingly, a molded type stator is positioned accurately, thus preventing the generation of burrs in the inner diametral section of the core.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention involves molding a stator by injecting a molding material into the mold with a stator core wound with a coil being housed in the mold. This relates to a molded stator H"tl.

[Technical Reason of the Invention] A conventional example of this type of molding apparatus will be explained with reference to FIGS. 5 and 6. Reference numerals 1 and 2 denote a pair of molds, an upper mold and a lower mold. A stepped cylindrical inner mold 6 is provided.

Then, with the stator core 8 with the coil 7 wound thereon stored in the molding recesses 3 and 5, a molding material 9 is injected into the molding parts 3.5 to mold the coil 7 and the stator core 8. . In this case, the stator core 8 is positioned by fitting the inner diameter part 10 of the stator core 8 into the inner mold 6, and the stepped portions 6a of the inner mold 6 are placed around the inner diameter part 10 on both axial end surfaces of the stator core 8. By arranging the inner mold part 4, the seven-fold material 9 is prevented from penetrating into the inner diameter part 10 from both axial end faces.

[Problems with the Background Art] By the way, in the above conventional configuration, the inner diameter portion 1 of the stator core 8
Due to the structure in which the bus stator core 8 is fitted into the inner mold 6, a certain amount of clearance is provided between the two in order to improve the fit between the two. It is unavoidable that the positioning accuracy decreases due to displacement within the recesses 3 and 5. As a result, the stator core 8 is likely to be molded in an eccentric state with respect to the molding layer of the mold material 9, and such a stator When the motor is assembled together, the stator and rotor are eccentric, resulting in poor motor characteristics.Furthermore, in the stator core 8, between the magnetic pole parts 11 around which the coil 7 is wound, there is a gap between the adjacent magnetic poles. In order to prevent magnetic flux from leaking to the part 11 side, a thin part 12 is formed as shown in FIG. However, in the case of a stator core 8 with a thin wall portion 12 formed therein, the mechanical strength of the thin wall portion 12 is weakened, so the injection pressure of the molding material 9 causes the thin wall portion 12 to
There is a risk that the inner diameter portion 10 of the stator core 8 may be deformed so as to be pushed into the gap between the inner die 6 and the inner diameter portion 10 of the stator core 8. On the other hand, in the case of a stator core with a notch formed In this case, the mold material enters the gap between the inner diameter part of the stator core and the inner mold 6 through the notch, and a mold material riser is formed in the inner diameter part. Since such mold material bulges may peel off and cause a rotor locking accident, the molded layers must be removed one by one, which increases the number of man-hours and increases costs.

[Aspects of the Invention] The present invention has been made in consideration of the above circumstances, and its purpose is to improve the positioning accuracy of the stator core, and to prevent the thin portions of the magnetic poles from deforming due to the injection pressure of the molding material. It is an object of the present invention to provide a mold-type stator molding device that can prevent the mold material from entering into the inside diameter part from the notch part of the magnetic pole part and forming a flaw.

[Summary of the Invention] The molding device of the present invention includes a cylindrical fitting convex portion having a slotted groove extending in the axial direction and provided to removably fit the inner diameter portion of the stator core into one of the drawing molds. Then, by clamping both molds provided for use, the fitting protrusion is inserted into the inner side of the fitting convex portion, and the fitting convex portion is expanded in the radial direction, thereby causing the fitting convex portion to be attached to the stator core. The stator core is provided with an expanding protrusion that comes into contact with the inner diameter part of the stator core, thereby preventing a gap from forming between the fitting convex part and the inner diameter part of the stator core during molding.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Reference numeral 21 denotes a stator core, which includes an annular magnetic pole core 23 having a plurality of radially protruding magnetic pole parts 22, and a frame-shaped yoke core 2 fitted to the tip of the magnetic pole part 22.
It is composed of 4. A thin portion 23a is formed in the portion of the magnetic pole core 23 between each magnetic pole portion 22 in order to prevent magnetic flux from leaking to the adjacent magnetic pole portion 22 side.

25 is a coil wound around each 1&pole portion 22 via a bobbin 26. On the other hand, 27 and 28 are a pair of molds, an upper mold and a lower mold. The stator core 21 has a columnar inner mold part 30, and the outer diameter of the inner mold part 30 is set larger than the inner diameter of the inner diameter part 31 of the stator core 21. The lower mold 28 also includes a molding recess 32 that accommodates substantially the lower half of each coil 25, and a cylindrical inner mold 3 provided inside the molding recess 32 so as to be movable up and down.
3, the outer diameter of the inner mold 33 is set larger than the inner diameter of the inner diameter portion 31 of the stator core 21, and the inner mold 33 is urged upward by a compression spring 34. 35 is the lower mold 28 and upper mold 2 when the mold is clamped.
A gate 36 formed between the molding recesses 29 and 32 is an injection machine that injects the molding material 37 into the molding recesses 29 and 32 through the gate 35. Thus, 38 is, for example, the inner mold 33 of the lower mold 28.
The fitting convex part is provided upright on the upper part, and is formed in a cylindrical shape with a plurality of slotted grooves 39 (see Fig. 3) extending in the axial direction, and can be expanded and contracted in the radial direction by the slotted grooves 39. There is. When the mold is opened, the outer diameter of the fitting protrusion 38 is set to be smaller than the inner diameter of the inner diameter part 31 of the stator core 21, so that the inner diameter part 31 of the stator core 21 is attached to the fitting protrusion 38. Can be inserted and removed (■
I try to do that. Furthermore, the inner circumferential surface of this fitting convex portion 38 is formed into a tapered surface shape that widens upward. 40
is an expansion protrusion provided in a hanging shape at the lower part of the inner mold part 30 of the upper mold 27, and the outer circumferential surface of this is formed in an underlined taper shape corresponding to the inner circumferential surface of the fitting convex part 38. . The expansion protrusion 40 is located directly above the fitting protrusion 38, and by clamping both the upper and lower molds 27° 28, the expansion protrusion 40 is
0 enters the inside of the fitting protrusion 38 and pushes the fitting protrusion 38 outward in the radial direction, thereby causing the fitting protrusion 38 to come into contact with the inner diameter portion 31 of the stator core 21. .

Next, the operation of the above embodiment will be explained. coil 25
When molding the stator core 21 wrapped with the stator core 21, first raise the upper mold 27 to open the mold, and then insert one inner diameter portion 31 of the stator core 21 into the one convex portion of the lower mold 28.
38 and accommodate the stator core 21 and coil 25 in the molding recess 32, the upper mold 27 is lowered to clamp the mold. After this, as the upper die 27 is cast once, the expansion protrusion 40 enters the inside of the fitting convex part 38, and in the middle of the process, the taper on the outer periphery of the expansion protrusion 8IX40 touches the fitting convex part 38.
The tapered inner circumference is in contact with the inner circumference, and as the upper mold 27 descends after the L-zip, the expanding protrusion 40 presses and expands the fitting convex part 38 in the radial direction, and finally the upper mold 27 touches the lower mold. 28 and the mold clamping is completed, the fitting convex portion 38 is brought into contact with the inner diameter portion 31 of the stator core 21. Moreover, by this mold clamping, the inner mold part 30 and the inner mold 33 are applied around the inner diameter part 31 on both axial end surfaces of the stator core 21, and thereby the mold material is transferred from the axial direction both end surfaces to the inside of the inner diameter part 31. 37 intrusion is prevented. After that, delete 1
Molten molding material 37 is injected from 36 into the molding recesses 29 and 32 through the gates 1-35 and solidified, thereby molding the coil 25 and stator core 21.

When the molding material 37 is injected, the expanding protrusion 40 holds the fitting protrusion 38 in contact with the inner diameter part 31 of the stator core 21 by clamping the mold, so that the fitting protrusion 38
No gap is formed between the inner diameter portion 31 of the stator core 21 and the stator core 21 is prevented from shifting relative to the fitting convex portion 38 due to the injection pressure of the molding material 37, and the positioning of the stator core 21 is prevented. can be molded with high precision. Moreover, in this case, even if the mechanical strength of the thin wall portion 23a of the inner diameter portion 31 of the stator core 21 is weak, the fitting convex portion 38 comes into contact with the inner diameter portion 31 of the stator core 21 during molding. Since the inner diameter portion 31 is reinforced from the inside, it is possible to reliably prevent the thin wall portion 23a from deforming inwardly due to the injection pressure of the molding material 37, and the inner diameter portion 31 of the stator core 21 after molding can be Can maintain good roundness. Furthermore, since the fitting convex portion 38 is expanded in the radial direction by mold clamping and brought into contact with the inner diameter portion 31 of the stator core 21, when the mold is opened, the fitting convex portion 38 is reduced in diameter to its original state. The fitting convex portion 38 is elastically deformed to form a gap between the fitting convex portion 38 and the inner diameter portion 31. For this reason, the stator core 2 is carried out with the mold open during the molding process.
The fitting work between the inner diameter part 31 and the fitting convex part 38 of No. 1 and the work of taking it out are easy due to the existence of the gap, and during the work, the inner diameter part 31 is not scratched by the fitting convex part 38. The above-mentioned gap can also prevent it from being put away as much as possible.

Furthermore, in the above embodiment, the inner mold 33 of the lower mold 28 is provided to be movable up and down, and the inner mold 33 is urged upward by the compression spring 34, so that the thickness dimension of the stator core 21 varies. However, this can be absorbed by the displacement of the compression spring 34 (the vertical displacement of the inner mold 33), and the inner mold 33 and the inner mold part 30 can be reliably applied to both end surfaces of the stator core 21. .

Note that the above embodiment is an example of application to the stator core 21 in which the thin wall portion 23a for preventing magnetic flux leakage is provided between the magnetic pole portions 22, but the present invention is not limited to this, and other embodiments not shown in FIG. The present invention can also be applied to the stator core 42 in which the magnetic flux leakage prevention notch 41 is formed in the magnetic pole portion 221XI to separate the magnetic pole portion 221XI. In such an embodiment, the fitting convex portion 3B comes into contact with the inner diameter portion 31 of the stator core 42 due to mold clamping, so that the two are brought into close contact with each other, so that the notch portion 41 is fitted from inside the inner diameter portion 31 Since the convex portion 38 securely closes the mold material 37 from the cutout portion 41 to the inside of the inner diameter portion 31.
The mold material 3 can be reliably prevented from entering the inner diameter part 31.
7 can be prevented from being formed.

In the above embodiment, the lower die 28 is provided with the fitting protrusion 38 and the upper die 27 is provided with the expansion protrusion 40, but on the contrary, the upper die is provided with the fitting protrusion 38. Alternatively, the lower mold may be provided with an expanding protrusion.

[Effects of the Invention] As is clear from the above description, the present invention allows the expansion protrusion to be inserted into the fitting convex portion with the slotted groove by clamping the mold. Since the mating convex part is pushed out in the radial direction and brought into contact with the inner diameter part of the stator core, it is possible to eliminate the gap between the inner diameter part of the stator core and the mating convex part during molding, and thus the stator core It is possible to improve the positioning accuracy of the magnetic pole part, and also to prevent the thin part of the magnetic pole part from being deformed by the injection pressure of the molding material. It has the excellent effect of preventing the formation of

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention,
1 is a cross-sectional view taken along line I-I in FIG. 2, FIG. 2 is a cross-sectional view of the whole, FIG.
The figure is a diagram equivalent to Figure 2 showing another embodiment of the present invention, Figures 5 and 6 show conventional examples, and Figure 5 is shown along the v-v line in Figure 6. The sectional view, FIG. 6, is a view corresponding to FIG. 2. In the drawing, 21 is a stator core, 25 is a coil, 27 is an upper die (molding die), 28 is a lower die (molding die), 31 is an inner diameter part,
37 is a molding material, 38 is a fitting convex portion, 39 is a slotted groove,
40 is an expansion protrusion, and 42 is a stator core. Applicant Toshiba Corporation Figure 2 Figure 3 Figure 14 Figure 5 Figure 6

Claims (1)

[Claims] 1. With the stator core wound with the coil wound in a pair of molds placed around the inner diameter of both axial end faces of the stator core, mold material is placed in the molds. A cylindrical fitting having a slotted groove extending in the axial direction and provided to removably fit the inner diameter part of the stator core into one of the two molds. By clamping the convex portion and both molds provided on the other side, the fitting convex portion is pushed into the stator core by entering the inside of the convex portion and pushing the convex portion outward in the radial direction. A device for forming a molded stator, comprising an expansion protrusion that is brought into contact with the inner diameter of the stator.