Manufacturing device of rotor

Abstract

To provide a manufacturing device of a rotor capable of suppressing a sudden increase in filling pressure.SOLUTION: A manufacturing device 70 of a rotor includes: a first member 20 that contacts one end face 11c of a rotor core 11 and closes a first opening 13a of a magnet accommodating hole 13 that opens into one end surface 11c; and a second member 30 disposed to close a second opening 13b of the magnet accommodating hole 13 and having a main passage 40 supplying molten thermoplastic resin to the second opening 13b. The second member 30 has a sub-passage 50 connected to the main passage 40. The sub-passage 50 is fitted with a pressure absorbing mechanism 60 which absorbs the filling pressure of the thermoplastic resin when the filling pressure of the thermoplastic resin reaches and rises above a predetermined value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an apparatus for manufacturing a rotor. [Background technology]

[0002] Patent Document 1 describes a resin filling device for embedding permanent magnets housed in magnet insertion holes provided in a rotor core with resin. This device includes an upper mold and a lower mold that are arranged vertically opposite each other.

[0003] The upper die has an upper die body portion formed with a contact surface that contacts the upper surface of the rotor core, and a fixing block that protrudes downward from the contact surface. The lower mold has a lower mold body and a runner plate attached to the upper surface of the lower mold body. The lower mold body is formed with a sprue portion which is a passage for guiding resin from the injection molding machine. The runner plate is provided with branch passages which are connected to the downstream end of the sprue portion and extend toward each magnet insertion hole of the rotor core, and a gate portion which is connected to the downstream end of the branch passage.

[0004] In such an apparatus, when molten thermoplastic resin is flowed from an injection molding machine into the sprue portion, the resin that has flowed into the sprue portion passes through each branch passage and the gate portion and is injected into the magnet insertion hole. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 147211 Summary of the Invention [Problem to be solved by the invention]

[0006] However, such devices have a problem that a sudden pressure rise, so-called surge pressure, occurs just before the filling of the resin is completed due to the high viscosity of the thermoplastic resin. Conventionally, measures have been required to ensure that the bridge width of the rotor core is sufficiently large to prevent deformation such as cracks in the bridge due to such a sudden pressure rise. However, in this case, another problem occurs in that the motor performance is reduced due to the large bridge width. [Means for solving the problem]

[0007] A rotor manufacturing apparatus for solving the above problem is an apparatus for manufacturing a rotor comprising a cylindrical rotor core having a plurality of magnet accommodating holes in which magnets are housed, and thermoplastic resin filled into the magnet accommodating holes, and comprises: a first member abutting one end face of the rotor core and blocking a first opening of the magnet accommodating hole that opens onto the end face; and a second member arranged to block a second opening on the opposite side of the magnet accommodating hole to the first opening, and having a main passage for supplying the molten thermoplastic resin to the second opening, wherein the second member is provided with a secondary passage connected to the main passage, and the secondary passage is fitted with a pressure absorption mechanism for absorbing the filling pressure of the thermoplastic resin when the filling pressure rises above a predetermined value.

[0008] In addition, a rotor manufacturing apparatus for solving the above problem is an apparatus for manufacturing a rotor comprising a cylindrical rotor core having a plurality of magnet accommodating holes in which magnets are housed, and thermoplastic resin filled into the magnet accommodating holes, and comprises: a first member abutting one end face of the rotor core and blocking a first opening of the magnet accommodating hole that opens onto the end face; and a second member arranged to block a second opening on the opposite side of the magnet accommodating hole to the first opening, and having a main passage for supplying the molten thermoplastic resin to the second opening, wherein the first member is provided with a secondary passage connected to the first opening, and the secondary passage is fitted with a pressure absorption mechanism for absorbing the filling pressure of the thermoplastic resin when the filling pressure rises above a predetermined value.

[0009] Further, a rotor manufacturing apparatus for solving the above problem is an apparatus for manufacturing a rotor including a cylindrical rotor core having a central hole and a plurality of magnet accommodating holes in which magnets are accommodated, and thermoplastic resin filled into the magnet accommodating holes, the apparatus comprising: a first member having a plate portion that abuts one end face of the rotor core and blocks a first opening of the magnet accommodating hole that opens into the end face, and a post portion that protrudes from the plate portion and is inserted into the central hole; a second member that is positioned to block a second opening on the opposite side of the magnet accommodating hole to the first opening; and a main passage constituted by the post portion and the second member and that supplies the molten thermoplastic resin to the second opening, the post portion being provided with a secondary passage connected to the main passage, and the secondary passage being equipped with a pressure absorption mechanism that absorbs the filling pressure of the thermoplastic resin when the filling pressure of the thermoplastic resin rises above a predetermined value.

[0010] According to these configurations, the sub-passage to which the pressure absorption mechanism is attached is connected to the main passage or the first opening. Therefore, the pressure absorption mechanism prevents the filling pressure from rising above a predetermined value. Therefore, a sudden rise in filling pressure can be prevented. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a rotor manufactured using a rotor manufacturing apparatus according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the rotor of FIG. [Diagram 3] FIG. 3 is a cross-sectional view showing a rotor manufacturing apparatus according to one embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the resin filling step. [Diagram 5] FIG. 5 is a cross-sectional view showing a modified example of the rotor manufacturing apparatus. [Figure 6] FIG. 6 is a cross-sectional view showing a modified example of the rotor manufacturing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, one embodiment of a rotor manufacturing apparatus will be described with reference to FIGS. <Rotor 10> First, a rotor 10 of an embedded magnet motor manufactured using a manufacturing apparatus 70 of the present embodiment will be described with reference to FIGS.

[0013] As shown in FIGS. 1 and 2, the rotor 10 includes a rotor core 11, magnets 14, and a thermoplastic resin 15 (hereinafter, resin 15). The rotor core 11 has a cylindrical shape and an axis C.

[0014] In the following description, the axial direction of rotor core 11 is simply referred to as the axial direction, the radial direction of rotor core 11 is simply referred to as the radial direction, and the circumferential direction of rotor core 11 is simply referred to as the circumferential direction. The rotor core 11 is formed by stacking a plurality of core pieces 12, which are punched out from electromagnetic steel sheets, in the axial direction.

[0015] The rotor core 11 has a central hole 11a and a plurality of magnet accommodating holes 13. The central hole 11a has a circular shape and penetrates the rotor core 11 in the axial direction. A pair of keys 11b facing each other in the radial direction protrude from the inner circumferential surface of the central hole 11a.

[0016] The magnet accommodating holes 13 are located radially outward of the central hole 11a and are spaced apart from one another in the circumferential direction. Each of the magnet accommodating holes 13 has a rectangular shape in a plan view and penetrates the rotor core 11 in the axial direction. Thus, the magnet accommodating holes 13 have a first opening 13a that opens into one end face 11c of the rotor core 11 in the axial direction (the lower side in the up-down direction in FIG. 1), and a second opening 13b on the opposite side to the first opening 13a.

[0017] The magnet accommodating holes 13 are inclined with respect to the circumferential direction. More specifically, the inclination directions with respect to the circumferential direction of two magnet accommodating holes 13 adjacent to each other in the circumferential direction are opposite to each other. Thus, the magnet accommodating holes 13 have an end 13c close to the outer peripheral surface 11e of the rotor core 11 and an end 13d far from the outer peripheral surface 11e.

[0018] 1, the rotor core 11 has a first bridge portion 16 and a second bridge portion 17. The first bridge portion 16 is a portion between adjacent magnet accommodating holes 13 in the circumferential direction. The second bridge portion 17 is a portion located between the outer circumferential surface 11e and the end portion 13c of the magnet accommodating hole 13.

[0019] 2, a magnet 14 is accommodated in each magnet accommodating hole 13. Magnet 14 has a rectangular parallelepiped shape extending in the axial direction. 2, the inside of each magnet accommodating hole 13 is filled with resin 15 for fixing the magnets 14 to the rotor core 11. The resin 15 is, for example, a liquid crystal polymer (LCP).

[0020] <Manufacturing equipment 70> Next, a manufacturing apparatus 70 for the rotor 10 will be described. As shown in FIG. 3, the manufacturing apparatus 70 includes a first member 20 on which the rotor core 11 is placed, a second member 30 arranged on the opposite side of the rotor core 11 from the first member 20 in the axial direction, and a pressure absorption mechanism 60.

[0021] In the following, the first member 20 side relative to rotor core 11 in the axial direction will be referred to as "bottom" or "lower side", and the second member 30 side relative to rotor core 11 will be referred to as "top" or "upper side".

[0022] <First member 20> As shown in FIG. 3, the first member 20 has a fixed mold 21 and a lamination jig 22 that supports the rotor core 11.

[0023] The fixed mold 21 has a support surface 21 a that supports a lower surface 22 a of the lamination jig 22 . The lamination jig 22 has a first plate portion 23, a pin 27, and a post portion . The first plate portion 23 has a lower plate 24 that constitutes the lower surface 22a of the stacking jig 22, and an upper plate 25 on which the rotor core 11 is placed.

[0024] The upper plate 25 has insertion holes 26. The insertion holes 26 are provided at positions overlapping with the magnet accommodating holes 13 in the axial direction. A pin 27 is inserted and fixed in the insertion hole 26. The pin 27 has a protruding portion 27a that protrudes upward from an upper surface 25a of the upper plate 25.

[0025] With the end face 11c of the rotor core 11 in contact with the upper face 25a of the upper plate 25, the first opening 13a of the magnet accommodating hole 13 is closed by the upper face 25a and the pin 27. The first plate portion 23 corresponds to the plate portion according to the present invention.

[0026] The post portion 28 is cylindrical and protrudes upward from the center of the lower plate 24. The post portion 28 penetrates the upper plate 25. The post portion 28 is inserted into the central hole 11a of the rotor core 11.

[0027] A pair of key grooves (not shown) into which the respective key portions 11b of rotor core 11 are inserted are provided on the outer circumferential surface of post portion 28. By inserting key portions 11b of rotor core 11 into the key grooves of post portion 28, the phase of rotor core 11 relative to lower plate 24, more specifically, the phase of each laminated block constituting rotor core 11, is determined.

[0028] A plurality of engagement pins 29 protruding upward are provided on the upper end 28a of the post portion 28. The engagement pins 29 are provided at intervals from one another in the circumferential direction. <Second member 30> As shown in FIG. 3, the second member 30 has a second plate portion 31 and a movable die .

[0029] The second plate portion 31 is placed on the end surface 11d of the rotor core 11 so as to close the second opening 13b of the magnet accommodating hole 13. The lower surface 31b of the second plate portion 31 is provided with a plurality of engagement holes 33 configured so that the engagement pins 29 can be engaged therewith.

[0030] The movable die 34 is provided on the opposite side of the first member 20 to the fixed die 21 of the first member 20 across the second plate portion 31, so as to be movable forward and backward relative to the fixed die 21 of the first member 20. The movable die 34 has a first movable die 34A and a second movable die 34B configured to be separable relatively to the first movable die 34A. The first movable die 34A and the second movable die 34B are each provided with a groove portion 35 and a groove portion 36 that face each other in the separation direction.

[0031] As shown in FIG. 3, the second member 30 has a main passage 40 that supplies molten resin 15 to the second opening 13b, and a sub-passage 50 that is connected to the main passage 40. The main passage 40 has a sprue portion 41, and a plurality of branch passages 42 and a plurality of gate portions 43 provided corresponding to the plurality of magnet accommodating holes 13, respectively.

[0032] 3 and 4, the sprue portion 41 is a passage for guiding the molten resin 15 from a nozzle (not shown) of an injection molding machine, and penetrates the movable mold 34 in the axial direction. The sprue portion 41 is provided on the axis C.

[0033] The branch passages 42 are connected to the lower end 41a of the sprue portion 41 and extend radially outward in the radial direction. The branch passages 42 are defined by a groove portion 32 formed in the upper surface 31a of the second plate portion 31 and a lower surface 34a of the movable mold 34.

[0034] The gate portion 43 is connected to a radially outer end of the branch passage 42 and extends in the axial direction. The gate portion 43 opens to the lower surface 31b of the second plate portion 31. The sub-passage 50 has a storage chamber 51 formed inside the movable die 34 and a connecting passage 52 extending from the storage chamber 51 in the axial direction and opening at the lower surface 34a of the movable die 34.

[0035] The connecting passage 52 connects the branch passage 42 and the storage chamber 51 . The sub-passage 50 is defined by a groove 35 formed in the first movable die 34A and a groove 36 formed in the second movable die 34B.

[0036] <Pressure absorption mechanism 60> The accommodation chamber 51 is provided with a pressure absorbing mechanism 60 that absorbs pressure by utilizing the elastic force of a coil spring 61. The pressure absorbing mechanism 60 is configured to absorb the filling pressure when the filling pressure of the resin 15 increases to or exceeds a predetermined value.

[0037] Next, the operation of this embodiment will be described. 3, the second plate portion 31 is placed on the end surface 11d of the rotor core 11 supported by the lamination jig 22. At this time, the gate portion 43 is connected to the second opening 13b of the magnet accommodating hole 13. Note that a plurality of magnets 14 are accommodated in the magnet accommodating hole 13 in advance.

[0038] Next, the stacking jig 22 is placed on the fixed die 21 of the first member 20. Thereafter, the movable die 34 descends and comes into contact with the upper surface 31a of the second plate portion 31. As a result, the rotor core 11 supported by the stacking jig 22 is fixed in a sandwiched state between the fixed die 21 and the movable die 34.

[0039] 4, when molten resin 15 is flowed into sprue portion 41 at a predetermined pressure by an injection molding machine (not shown), resin 15 fills the inside of each magnet accommodating hole 13 through a plurality of branch passages 42 and a plurality of gate portions 43. At this time, resin 15 is also filled into sub-passage 50 connected to branch passage 42.

[0040] Just before the filling of the resin 15 into the magnet accommodating hole 13 is completed, a sudden pressure rise, so-called surge pressure, occurs due to the high viscosity of the resin 15. When the filling pressure rises above a predetermined value, the pressure absorption mechanism 60 is activated to absorb the surge pressure.

[0041] When filling of the resin 15 into the magnet accommodating holes 13 is completed, the resin 15 in the magnet accommodating holes 13 is cooled and solidified. This fixes the laminated blocks of the rotor core 11 to each other and fixes the magnets 14 to the rotor core 11.

[0042] Next, the effects of this embodiment will be described. A sub-passage 50 to which a pressure absorbing mechanism 60 is attached is connected to the branch passage 42 of the main passage 40. Therefore, the pressure absorbing mechanism 60 prevents the filling pressure of the resin 15 from rising above a predetermined value. As a result, a sudden rise in filling pressure, that is, a so-called surge pressure, is suppressed.

[0043] Conventionally, in order to prevent such a sudden increase in pressure from causing deformation such as cracks in the first bridge portion 16 and the second bridge portion 17 of the rotor core 11, it has been necessary to take measures such as ensuring a sufficient width for both bridge portions 16, 17. In such cases, problems such as a decrease in the performance of the motor equipped with the rotor 10 arise.

[0044] The above configuration eliminates the need to take measures such as ensuring sufficient width for the first bridge portion 16 and the second bridge portion 17 in the rotor core 11. Therefore, it is possible to suppress a decrease in motor performance caused by increasing the width of both bridge portions 16, 17.

[0045] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0046] The resin 15 is not limited to a liquid crystal polymer, and any suitable thermoplastic resin may be selected and used. The pressure absorbing mechanism 60 is not limited to one that uses the coil spring 61, and may be of a hydraulic type.

[0047] The sub-passage 50 is not limited to being connected to the branch passage 42 as illustrated in this embodiment. For example, it may be connected to the sprue portion 41. In this case, it is sufficient that the sub-passage 50 is connected to the sprue portion 41 from the radial outside.

[0048] The sub-passage 50 is not limited to being provided in the movable die 34 as illustrated in this embodiment, and the arrangement can be changed as appropriate as long as it is provided in the second member 30 and connected to the main passage 40. For example, it may be provided in the second plate portion 31.

[0049] The manufacturing apparatus according to the present invention is not limited to one in which the bypass passage 50 is provided in the second member 30. For example, the following modifications may be made. That is, as shown in Fig. 5, a manufacturing apparatus 170 may be one in which a bypass passage 150 connected to the first opening 13a is provided in the first member 120. In this case, a pressure absorbing mechanism 160 may be provided in the accommodation chamber 151 of the bypass passage 150.

[0050] According to this configuration, the first opening 13a is connected to the sub-passage 150 to which the pressure absorbing mechanism 160 is attached. Therefore, the pressure absorbing mechanism 160 prevents the filling pressure of the resin 15 from increasing to a predetermined value or higher. Therefore, even with this manufacturing apparatus 170, a sudden increase in the filling pressure can be prevented, similar to the manufacturing apparatus 70 exemplified in this embodiment.

[0051] The manufacturing apparatus according to the present invention is not limited to the shape exemplified in this embodiment. For example, it may be modified as follows. That is, as shown in FIG. 6, the manufacturing apparatus 270 may be one in which the post portion 228 of the first member 220 penetrates the second plate portion 231. In this case, the main passage 240 is defined by the upper end 228a of the post portion 228, the groove portion 232 of the second plate portion 231, and the lower surface 234a of the movable mold 234. That is, the main passage 240 is formed by the post portion 228 and the second member 230. Also, in this case, the sub-passage 250 may be provided in the post portion 228 and connected to the branch passage 242. Also, a pressure absorbing mechanism 260 may be provided in the accommodation chamber 251 of the sub-passage 250.

[0052] According to this configuration, the sub-passage 250 to which the pressure absorbing mechanism 260 is attached is connected to the main passage 240. Therefore, the pressure absorbing mechanism 260 suppresses the filling pressure of the resin 15 from increasing to a predetermined value or higher. Therefore, even with this manufacturing apparatus 270, it is possible to suppress a sudden increase in filling pressure, similar to the manufacturing apparatus 70 exemplified in this embodiment. [Explanation of symbols]

[0053] C…Axis line 10...Rotor 11...Rotor core 11a...Center hole 11b...Key section 11c...end face 11d...end face 11e...Outer surface 13...Magnet receiving hole 13a...first opening 13b…Second opening 14…Magnet 15...Thermoplastic resin, resin 20, 120, 220…First member 28,228…Post Office 30,230…Second member 40,240…Main passage 50,150,250…Sub-aisle 60, 160, 260... Pressure absorption mechanism 70,170,270…Manufacturing equipment

Claims

1. An apparatus for manufacturing a rotor including a cylindrical rotor core having a plurality of magnet accommodating holes in which magnets are accommodated, and a thermoplastic resin filled in the magnet accommodating holes, comprising: a first member that contacts one end surface of the rotor core and closes a first opening of the magnet accommodating hole that opens into the end surface; a second member disposed to close a second opening on the opposite side of the first opening of the magnet accommodating hole, the second member having a main passage for supplying the molten thermoplastic resin to the second opening, The second member is provided with a sub-passage connected to the main passage, a pressure absorbing mechanism is attached to the sub-passage to absorb the filling pressure of the thermoplastic resin when the filling pressure of the thermoplastic resin increases to or exceeds a predetermined value; Rotor manufacturing equipment.

2. An apparatus for manufacturing a rotor including a cylindrical rotor core having a plurality of magnet accommodating holes in which magnets are accommodated, and a thermoplastic resin filled in the magnet accommodating holes, comprising: a first member that contacts one end surface of the rotor core and closes a first opening of the magnet accommodating hole that opens into the end surface; a second member disposed to close a second opening on the opposite side of the first opening of the magnet accommodating hole, the second member having a main passage for supplying the molten thermoplastic resin to the second opening, The first member is provided with a sub-passage connected to the first opening, a pressure absorbing mechanism is attached to the sub-passage to absorb the filling pressure of the thermoplastic resin when the filling pressure of the thermoplastic resin increases to or exceeds a predetermined value; Rotor manufacturing equipment.

3. An apparatus for manufacturing a rotor comprising: a cylindrical rotor core having a central hole and a plurality of magnet accommodating holes in which magnets are accommodated; and a thermoplastic resin filled in the magnet accommodating holes, a first member including a plate portion that abuts against one end surface of the rotor core and closes a first opening of the magnet accommodating hole that opens into the end surface, and a post portion that protrudes from the plate portion and is inserted into the central hole; a second member arranged to close a second opening of the magnet accommodating hole on an opposite side to the first opening; a main passage formed by the post portion and the second member and supplying the molten thermoplastic resin to the second opening, The post portion is provided with a sub-passage connected to the main passage, a pressure absorbing mechanism is attached to the sub-passage to absorb the filling pressure of the thermoplastic resin when the filling pressure of the thermoplastic resin increases to or exceeds a predetermined value; Rotor manufacturing equipment.

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