Multi-cavity die casting die for aluminum rotor and motor rotor

Abstract

The application relates to the technical field of cast aluminum rotors, in particular to a multi-cavity cast aluminum rotor die-casting die and a motor rotor. The die-casting die comprises an upper die, a middle die and a lower die, the middle die is provided with a plurality of main cavities; the upper die is provided with upper end ring grooves corresponding to the main cavities, and the center of each upper end ring groove is provided with a dummy shaft hole; the lower die is provided with lower end ring grooves corresponding to the main cavities, and the center of each lower end ring groove is provided with a positioning groove; a rotor iron core is placed in the main cavities, the main cavities are cylindrical holes and are in gap cooperation with the rotor iron core; a dummy shaft assembly is placed in the dummy shaft hole, the transverse extrusion of the dummy shaft assembly improves the shaft hole quality of the cast aluminum rotor, prevents aluminum liquid from being extruded into the gaps between the rotor iron core and the lamination, reduces the transverse current and reduces the additional loss of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cast aluminum rotor, in particular to a multi-cavity cast aluminum rotor die-casting die and motor rotor. BACKGROUND

[0002] The cast aluminum rotor is a key component in asynchronous motor, and its manufacturing process mainly includes mold design, rotor core preparation, aluminum melting and pouring, cooling and demolding, post-processing and quality detection, etc. First, the mold is made according to the rotor design drawing, and the mold is usually made of high-temperature-resistant material to ensure that it can withstand the impact of high-temperature aluminum liquid and maintain accurate dimensions. Then the silicon steel sheets are stacked into the rotor core, and the stacking coefficient and axial length of the rotor core need to be strictly controlled to ensure its electromagnetic performance. After the rotor core is stacked, it is placed in the preheated mold to prepare for aluminum casting. The aluminum melting process is to heat pure aluminum or aluminum alloy to a molten state and remove impurities and oxides to ensure the purity of the aluminum liquid. When pouring, the molten aluminum is poured into the mold through centrifugal casting or pressure casting to fill the slot part and end ring part of the rotor core. Centrifugal casting uses centrifugal force to make the aluminum liquid uniformly distributed, while pressure casting ensures that the aluminum liquid fully fills every corner of the mold through external pressure. After pouring is completed, the rotor enters the cooling stage and is demolded after the aluminum liquid solidifies. The demolded rotor needs to be deburred, polished and surface treated to remove excess aluminum chips and burrs, ensuring that the appearance and size of the rotor meet the requirements. Finally, dynamic balance test and electrical performance test are carried out to ensure that the balance and electromagnetic performance of the rotor meet the standards when it runs at high speed. The entire manufacturing process requires high precision and consistency to ensure that the performance and reliability of the cast aluminum rotor meet the working requirements of the motor.

[0003] The common cast aluminum methods include low-pressure cast aluminum, centrifugal cast aluminum and pressure cast aluminum. Among the three cast aluminum methods, the additional loss of the pressure cast aluminum rotor motor is the largest. This is because the powerful pressure during pressure casting makes the lamination and the core contact very closely, and the aluminum liquid is squeezed into the lamination, increasing the transverse current and greatly increasing the additional loss of the motor. Moreover, due to the uneven quality of the shaft hole processing of the lamination, the shaft hole quality may be affected after cast aluminum due to misalignment of the shaft hole of the lamination, making the assembly of the true shaft and the cast aluminum rotor difficult. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a multi-cavity cast aluminum rotor die-casting die and motor rotor. By setting a false shaft assembly in the cast aluminum rotor die-casting die to exert transverse extrusion on the rotor core, the shaft hole quality of the cast aluminum rotor is improved. In combination with the protruding part on the rotor core, it can also prevent the aluminum liquid from being squeezed into the gap between the rotor core lamination, reduce the transverse current and reduce the additional loss of the motor.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A multi-cavity aluminum rotor die-casting mold, comprising an upper mold, a middle mold, and a lower mold, the middle mold is provided with a plurality of main cavities; the upper mold is provided with an upper end ring groove corresponding to the main cavity, and the center of the upper end ring groove is provided with a false shaft hole; the lower mold is provided with a lower end ring groove corresponding to the main cavity, and the center of the lower end ring groove is provided with a positioning groove; the rotor core is placed in the main cavity, and the main cavity is a cylindrical hole and is matched with the rotor core; the false shaft assembly is placed in the false shaft hole, the false shaft assembly passes through the shaft hole in the middle of the rotor core, and the lower end of the false shaft assembly is matched with the positioning groove; the extrusion assembly on the false shaft assembly acts on the side surface of the shaft hole to realize the positioning of the punching sheet of the rotor core, and at the same time, the gap formed between the punching sheets is closed.

[0007] Further, the middle mold is provided with a plurality of guide column holes; the upper mold and the lower mold are respectively provided with upper guide columns and lower guide columns matched with the guide column holes; the lower mold is further provided with a plurality of injection ports communicated with the lower end ring groove; the lower end of the lower mold is provided with a positioning boss matched with a die-casting cylinder.

[0008] Further, the false shaft assembly comprises a shaft cylinder matched with the upper mold and the lower mold; a driving shaft is slidably arranged in the middle of the shaft cylinder; the extrusion assembly comprises a first extrusion part and a second extrusion part arranged in different directions; the driving shaft is in transmission connection with the first extrusion part and the second extrusion part; the first extrusion part comprises a connecting rod structure, and the second extrusion part comprises a wedge block structure; the shaft cylinder is provided with a positioning block limiting the moving direction of the driving shaft.

[0009] Further, the upper end of the shaft cylinder is provided with an upper positioning part matched with the false shaft hole of the upper mold; the lower end of the shaft cylinder is provided with a lower positioning part matched with the positioning groove of the lower mold; the driving shaft is provided with a limiting groove, and the oppositely arranged positioning blocks on the shaft cylinder are in clamping connection with the limiting groove; one end of the driving shaft protruding out of the shaft cylinder is connected with an external actuating mechanism, and the other end of the driving shaft is provided with a first hinge shaft and a first wedge block; the first hinge shaft is connected with the connecting rod structure of the first extrusion part; the first wedge block is connected with the wedge block structure of the second extrusion part.

[0010] Further, the connecting rod structure of the first extrusion part comprises a driving rod and a supporting rod; one end of the driving rod is hingedly connected with the first hinge shaft of the driving shaft, and the other end is hingedly connected in the middle of the supporting rod; one end of the supporting rod is hingedly connected with the second hinge shaft of the shaft cylinder, and the other end is in transmission connection with an extrusion block.

[0011] Further, the extrusion block has an arc-shaped end face matched with the shaft hole of the rotor core; the other side of the arc-shaped end face of the extrusion block is provided with a convex rib, and a plurality of waist-shaped holes are arranged on the convex rib; the end of the supporting rod is provided with a sliding pin in sliding connection with the waist-shaped hole; the middle of the supporting rod is provided with a shaft connected with the driving rod.

[0012] Further, the first wedge block is two and symmetrically arranged on both sides of the driving shaft; the wedge block structure of the second extrusion part comprises a second wedge block and a guide block; the second extrusion part has an arc-shaped end face matched with the rotating shaft hole of the rotor core, the second wedge block is arranged on the other side of the arc-shaped end face of the second extrusion part; the second wedge block is in abutment with the first wedge block of the driving shaft; the two sides of the guide block are provided with guide parts which are slidingly arranged in the guide groove of the shaft cylinder.

[0013] The motor rotor of the application is made by the above-mentioned die-casting aluminum rotor die-casting mold, the rotor core is pressed from a plurality of punching sheets, the middle part of the punching sheet is provided with a rotating shaft hole, and a plurality of bar grooves are arranged in the circumferential direction of the punching sheet; the outer circular end face of the punching sheet of the rotor core is gap-fitted and positioned with the main cavity of the middle mold; after the mold is closed, the extrusion assembly of the dummy shaft assembly abuts against the rotating shaft hole of the punching sheet of the rotor core to form an inner circular end face.

[0014] Further, a second protruding part is arranged around the lower opening of the rotating shaft hole of the punching sheet; a first protruding part is arranged around the lower opening of the bar groove; the inclined end face formed by the first protruding part and the hole wall of the bar groove and the inclined end face formed by the second protruding part and the hole wall of the rotating shaft hole all have an included angle with the vertical direction.

[0015] Further, the upper mold pressing table of the upper mold presses the upper part of the rotor core after the mold is closed; the lower mold pressing table of the lower mold abuts against the lower part of the rotor core; the extrusion assembly of the dummy shaft assembly transversely extrudes the second protruding part of the rotating shaft hole of the rotor core, and the aluminum liquid conveyed by the die-casting machine transversely extrudes the first protruding part of the bar groove of the rotor core, so that the gap between the punching sheets of the rotor core has a closing trend.

[0016] Compared with the prior art, the application provides a multi-cavity die-casting aluminum rotor die-casting mold and a motor rotor, which have the following beneficial effects: the dummy shaft assembly arranged in the die-casting aluminum rotor die-casting mold can apply transverse extrusion to the rotating shaft hole of the rotor core, so that the shaft hole of the die-casting aluminum rotor after die-casting has higher flatness, the quality of the shaft hole of the die-casting aluminum rotor is improved to facilitate subsequent assembly with the motor true shaft; at the same time, the punching sheet of the rotor core is provided with a vertically extending protruding part, and after the rotor core is transversely extruded by the dummy shaft assembly, the gap between the punching sheets has a closing trend, the aluminum liquid is reduced / prevented from being extruded into the gap between the punching sheets, the transverse current of the motor is reduced, and the additional loss of the motor is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a whole structure schematic diagram of the multi-cavity die-casting aluminum rotor die-casting mold of the application;

[0018] Figure 2 It is an exploded view of the multi-cavity die-casting aluminum rotor die-casting mold of the application;

[0019] Figure 3 Structure diagram of the upper die of the present application;

[0020] Figure 4 Structure diagram of the lower die of the present application;

[0021] Figure 5 Sectional view of the lower die of the present application;

[0022] Figure 6 Sectional view of the multi-cavity aluminum rotor die casting mold of the present application;

[0023] Figure 7 Initial state diagram of the dummy shaft assembly of the present application;

[0024] Figure 8 Extrusion state diagram of the dummy shaft assembly of the present application;

[0025] Figure 9 Sectional view of the dummy shaft assembly of the present application in another direction;

[0026] Figure 10 Exploded view of the dummy shaft assembly of the present application;

[0027] Figure 11 Sectional view of the dummy shaft assembly of the present application;

[0028] Figure 12 Structure diagram of the rotor core of the present application;

[0029] Figure 13 Structure diagram of the punching sheet of the present application;

[0030] Figure 14 Sectional view of the punching sheet of the present application;

[0031] Figure 15 Sectional view of the rotor core of the present application;

[0032] In the drawings:

[0033] Dummy shaft assembly 1, driving shaft 11, first hinge shaft 111, first wedge block 112, limiting groove 113, shaft cylinder 12, upper positioning part 121, lower positioning part 122, second hinge shaft 123, guide groove 124, extrusion assembly 13, positioning block 14, first extrusion part 15, driving rod 151, support rod 152, sliding pin 1521, rotating shaft 1522, extrusion block 153, waist-shaped hole 1531, second extrusion part 16, second wedge block 161, guide block 162;

[0034] Upper die 2, dummy shaft hole 21, upper die pressing table 211, upper guide column 22, upper end ring groove 23;

[0035] Middle die 3, main cavity 31, guide pillar hole 32;

[0036] Lower die 4, lower end ring groove 41, positioning groove 42, lower die pressing platform 421, lower guide pillar 43, injection port 44, positioning boss 45;

[0037] Rotor core 5, punched sheet 51, bar groove 511, rotation shaft hole 512, first protruding part 501, second protruding part 502, gap 50. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application. Figures 1-15 The present application is described in detail below. The present application is a multi-cavity aluminum rotor die-casting mold, which comprises an upper die 2, a middle die 3, and a lower die 4. The middle die 3 is provided with a plurality of main cavities 31. The upper die 2 is provided with upper end ring grooves 23 corresponding to the main cavities 31, and the center of each upper end ring groove 23 is provided with a dummy shaft hole 21. The lower die 4 is provided with lower end ring grooves 41 corresponding to the main cavities 31, and the center of each lower end ring groove 41 is provided with a positioning groove 42. A rotor core 5 is placed in each main cavity 31, and each main cavity 31 is a cylindrical hole and is in clearance fit with the rotor core 5. A dummy shaft assembly 1 is placed in the dummy shaft hole 21, and the dummy shaft assembly 1 passes through the rotation shaft hole 512 in the middle of the rotor core 5, and the lower end of the dummy shaft assembly 1 is in fit with the positioning groove 42. An extrusion assembly 13 on the dummy shaft assembly 1 acts on the side surface of the rotation shaft hole 512 to realize the positioning of the punched sheet 51 of the rotor core 5, and at the same time, the gap 50 formed between the punched sheets 51 is closed.

[0040] Specifically, when the aluminum rotor is die-cast, strong pressure may cause the aluminum liquid to be squeezed into the gap 50 between the punched sheets 51, resulting in an increase in the transverse current of the motor and an increase in additional loss. At the same time, due to factors such as the quality fluctuation of the hole processing of the punched sheet 51, the rotation shaft hole 512 of the punched sheet 51 cannot be aligned during the die-casting process, thereby reducing the quality of the shaft hole of the aluminum rotor and affecting the fit between the shaft hole of the aluminum rotor and the true shaft. The main cavities 31 on the middle die 3 of the present application position the outer circular end surface of the punched sheet 51 of the rotor core 5 through clearance fit. After the dummy shaft assembly 1 sequentially passes through the dummy shaft hole 21, the rotation shaft hole 512 of the rotor core 5, and is placed in the positioning groove 42 from top to bottom, the extrusion assembly 13 of the dummy shaft assembly 1 can protrude from the end surface of the dummy shaft assembly 1 in the transverse direction (such as the left-right direction), and by applying a transverse extrusion force G to the end surface of the rotation shaft hole 512 through the extrusion assembly 13, the punched sheet 51 of the rotor core 5 is positioned and fixed, and the gap 50 between the punched sheets 51 is closed. Figure 6 The extrusion assembly 13 of the dummy shaft assembly 1 can protrude from the end surface of the dummy shaft assembly 1 in the transverse direction (such as the left-right direction), and by applying a transverse extrusion force G to the end surface of the rotation shaft hole 512 through the extrusion assembly 13, the punched sheet 51 of the rotor core 5 is positioned and fixed, and the gap 50 between the punched sheets 51 is closed.Figure 15 The positioning of the punching sheet 51 of the rotor core 5 can be realized, and the gap 50 between the punching sheets 51 is closed by matching the protruding part structure on the punching sheet 51, so that the aluminum liquid is prevented from being squeezed into the gap 50.

[0041] The middle die 3 is provided with a plurality of guide pillar holes 32; the upper die 2 and the lower die 4 are respectively provided with upper guide pillars 22 and lower guide pillars 43 matched with the guide pillar holes 32; the lower die 4 is further provided with a plurality of injection ports 44 communicated with the lower end ring grooves 41; the lower end of the lower die 4 is provided with a positioning boss 45 matched with a die casting cylinder.

[0042] There are two guide pillar holes 32 on each of the four corners of the middle die 3 matched with the upper die 2 and the lower die 4, there are four upper guide pillars 22 on the four corners of the upper die 2, and there are four lower guide pillars 43 on the four corners of the lower die 4; the upper die 2, the middle die 3 and the lower die 4 form a cavity after clamping, the cavity includes a main cavity 31 for placing the rotor core 5, and an end ring cavity formed by the upper end ring grooves 23 and the lower end ring grooves 41 at the end of the cavity of the upper die 2 and the lower die 4; the two walls of the upper end ring grooves 23 and the lower end ring grooves 41 have a 1.5° draw slope to facilitate demolding; the injection port 44 is in the shape of a horn, with a large hole facing outward and a small hole facing inward to facilitate the removal of waste from the die casting hole.

[0043] The shaft assembly 1 includes a shaft cylinder 12 matched with the upper die 2 and the lower die 4; a driving shaft 11 is slidably arranged in the middle part of the shaft cylinder 12; the extrusion assembly 13 includes a first extrusion part 15 and a second extrusion part 16 arranged in different directions; the driving shaft 11 is in transmission connection with the first extrusion part 15 and the second extrusion part 16; the first extrusion part 15 includes a connecting rod structure, and the second extrusion part 16 includes a wedge block structure; the shaft cylinder 12 is provided with a positioning block 14 limiting the moving direction of the driving shaft 11.

[0044] Specifically, the shaft cylinder 12 is in a cylindrical structure, the middle part of the shaft cylinder 12 is provided with a through hole, the driving shaft 11 is slidably arranged in the through hole of the middle part of the shaft cylinder 12, the upper end of the driving shaft 11 extends out of the shaft cylinder 12 and is connected with an external driving structure, the lower end of the driving shaft 11 is in transmission connection with the first extrusion part 15 and the second extrusion part 16, and specifically, the first extrusion part 15 is symmetrically arranged on the two sides of the driving shaft 11 in a first direction, and the second extrusion part 16 is symmetrically arranged on the two sides of the driving shaft 11 in a second direction, wherein the first direction is perpendicular to the second direction, see FIG. 2. Figure 10 The first extrusion part 15 and the second extrusion part 16 convert the vertical movement of the driving shaft 11 into the horizontal movement of the extrusion assembly 13, so that after the extrusion assembly 13 is extended into the shaft hole 512 of the rotor core 5, the horizontal movement of the first extrusion part 15 and the second extrusion part 16 is generated by the actuation of the driving shaft 11, thereby providing the horizontal extrusion force G to the end face of the shaft hole 512.

[0045] The first extrusion part 15 comprises a connecting rod structure, and the second extrusion part 16 comprises a wedge structure. The connecting rod structure of the first extrusion part 15 can provide greater lateral displacement, facilitating positioning and alignment of the shaft hole 512 of the punching sheet 51. The wedge structure of the second extrusion part 16 can provide greater extrusion force, thereby better closing the gap 50 between the punching sheets 51.

[0046] The upper end of the shaft cylinder 12 is provided with an upper positioning part 121 matched with the dummy shaft hole 21 of the upper die 2. The lower end of the shaft cylinder 12 is provided with a lower positioning part 122 matched with the positioning groove 42 of the lower die 4. The driving shaft 11 is provided with a limiting groove 113. The positioning block 14 oppositely arranged on the shaft cylinder 12 is clamped with the limiting groove 113. The end of the driving shaft 11 protruding from the shaft cylinder 12 is connected with an external actuating mechanism. The other end of the driving shaft 11 is provided with a first hinge shaft 111 and a first wedge 112. The first hinge shaft 111 is connected with the connecting rod structure of the first extrusion part 15. The first wedge 112 is connected with the wedge structure of the second extrusion part 16.

[0047] Specifically, the first hinge shaft 111 has two groups arranged side by side, each group has two first hinge shafts 111, and the first hinge shafts 111 of each group are connected with the connecting rod structure of the first extrusion part 15 in opposite directions, as shown in FIG. 4. Figure 10 The connecting rod structure of each first extrusion part 15 is connected with two first hinge shafts 111 arranged side by side. The two groups of connecting rod structures make the first extrusion part 15 have stronger stability when being pushed out. The first wedge 112 has two and is symmetrically arranged on both sides of the driving shaft 11.

[0048] The connecting rod structure of the first extrusion part 15 comprises a driving rod 151 and a supporting rod 152. One end of the driving rod 151 is hinged with the first hinge shaft 111 of the driving shaft 11, and the other end is hinged in the middle of the supporting rod 152. One end of the supporting rod 152 is hinged with the second hinge shaft 123 of the shaft cylinder 12, and the other end is drivingly connected with the extrusion block 153.

[0049] Specifically, in the initial state, the included angle between the driving rod 151 and the driving shaft 11 is close to perpendicular and not perpendicular. The translation of the driving rod 151 drives the driving shaft 11 to rotate from close to perpendicular to perpendicular. In this angle range, the driving shaft 11 can exert the largest possible pushing force on the supporting rod 152, as shown in FIG. 5. Figures 7-11 One end of the supporting rod 152 is hinged with the second hinge shaft 123 of the shaft cylinder 12, and the other end is drivingly connected with the extrusion block 153 through a sliding structure, so that the supporting rod 152 can push the extrusion block 153 to protrude linearly from the shaft cylinder 12 and extrude the shaft hole 512 of the rotor core 5.

[0050] The extrusion block 153 has an arc-shaped end face matched with the rotating shaft hole 512 of the rotor core 5; the other side of the arc-shaped end face of the extrusion block 153 is provided with a convex rib, and a plurality of waist-shaped holes 1531 are arranged on the convex rib; the end of the supporting rod 152 is provided with a sliding pin 1521 which is in sliding fit with the waist-shaped hole 1531; and the middle part of the supporting rod 152 is provided with a rotating shaft 1522 connected with the driving rod 151.

[0051] Specifically, a slot hole is formed in the middle part of the supporting rod 152, the rotating shaft 1522 is arranged in the slot hole, and the shaft hole on the driving rod 151 is sleeved on the rotating shaft 1522, so that the driving rod 151 drives the supporting rod 152 to rotate; the back of the extrusion block 153 is provided with two convex ribs, two waist-shaped holes 1531 are arranged on each convex rib, the two sides of one end of the supporting rod 152 are provided with sliding pins 1521, the sliding pins 1521 on the two sides of the supporting rod 152 extend into the two oppositely arranged waist-shaped holes 1531, the slot hole on the shaft cylinder 12 limits the linear motion of the extrusion block 153, and the extrusion block 153 is driven to move linearly by the rotating supporting rod 152 cooperating with the waist-shaped hole 1531 and the sliding pin 1521, wherein the angle between the driving rod 151 and the driving shaft 11 can greatly increase the pushing force applied to the extrusion block 153.

[0052] The first wedge block 112 is arranged symmetrically on both sides of the driving shaft 11; the wedge block structure of the second extrusion part 16 comprises a second wedge block 161 and a guide block 162; the second extrusion part 16 has an arc-shaped end face matched with the rotating shaft hole 512 of the rotor core 5, and the second wedge block 161 is arranged on the other side of the arc-shaped end face of the second extrusion part 16; the second wedge block 161 abuts against the first wedge block 112 of the driving shaft 11; and the two sides of the guide block 162 are provided with guide parts which are slidingly arranged in the guide groove 124 of the shaft cylinder 12.

[0053] The motor rotor of the application is made by the above-mentioned cast aluminum rotor die casting mold, the rotor core 5 is pressed from a plurality of punching sheets 51; the middle part of the punching sheet 51 is provided with a rotating shaft hole 512, and a plurality of bar grooves 511 are formed in the circumferential direction of the punching sheet 51; the outer circular end face of the punching sheet 51 of the rotor core 5 is gap-fitted and positioned with the main cavity 31 of the middle mold 3; after the mold is closed, the extrusion assembly 13 of the false shaft assembly 1 abuts against the rotating shaft hole 512 of the punching sheet 51 of the rotor core 5 to form an inner circular end face.

[0054] The lower opening of the rotating shaft hole 512 of the punching sheet 51 is provided with a second convex part 502 around; the lower opening of the bar groove 511 is provided with a first convex part 501 around; the inclined end face formed by the first convex part 501 and the hole wall of the bar groove 511 and the inclined end face formed by the second convex part 502 and the hole wall of the rotating shaft hole 512 all have an included angle with the vertical direction.

[0055] Specifically, the guide bar groove 511 and the shaft hole 512 on the punched sheet 51 are punched by a punch, and in the punching process, the lower edge of the guide bar groove 511 and the shaft hole 512 is cut by a punch knife to form excess material, i.e., the first protrusion 501 and the second protrusion 502; and the hole wall of the guide bar groove 511 and the inclined end face formed by the first protrusion 501 have an angle A with the vertical direction, see Figure 14 , the hole wall of the shaft hole 512 and the inclined end face formed by the second protrusion 502 also have an angle with the vertical direction, and the above structure makes the gap 50 between the punched sheets 51 not only extend horizontally, but also have a vertical extension due to the presence of the first protrusion 501 and the second protrusion 502, so that after the second protrusion 502 is pressed by the transverse pressing assembly 13, it can play a role in closing the gap 50, thereby reducing and preventing the aluminum liquid from being squeezed into the gap 50.

[0056] After the mold is closed, the upper die pressing table 211 of the upper die 2 presses the upper part of the rotor core 5; the lower die pressing table 421 of the lower die 4 abuts against the lower part of the rotor core 5; the pressing assembly 13 of the dummy shaft assembly 1 transversely presses the second protrusion 502 of the shaft hole 512 of the rotor core 5, and the aluminum liquid delivered by the die casting machine transversely presses the first protrusion 501 of the guide bar groove 511 of the rotor core 5, so that the gap 50 between the punched sheets 51 of the rotor core 5 has a tendency to close.

[0057] The pressing assembly 13 of the dummy shaft assembly 1 applies a transverse pushing force G to the inner wall of the shaft hole 512 of the rotor core 5, see Figure 15 , so that the inner wall of the shaft hole 512 of the rotor core 5 has a higher flatness after die casting, improving the quality of the shaft hole of the cast aluminum rotor and facilitating subsequent assembly with the true shaft of the motor. At the same time, due to the presence of the vertically extending first protrusion 501 and the second protrusion 502 at the guide bar groove 511 and the shaft hole 512, the aluminum liquid delivered by the die casting machine applies a transverse pushing force F to the inner wall of the guide bar groove 511, which cooperates with the transverse pressing of the second protrusion 502 by the pushing force G, and the downward pressure generated by the upper die and the upward pressure generated by the lower die, to squeeze the volume occupied by the punched sheets 51 transversely, so that the gap 50 between the punched sheets 51 has a tendency to close at the first protrusion 501 and the second protrusion 502, thereby reducing and preventing the aluminum liquid from being squeezed into the gap between the punched sheets 51, thereby reducing the transverse current of the motor and reducing the additional loss of the motor.

[0058] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A multi-cavity aluminum rotor die-casting mold, comprising an upper mold (2), a middle mold (3), and a lower mold (4), characterized in that: the middle mold (3) is provided with a plurality of main cavities (31); the upper mold (2) is provided with an upper end ring groove (23) corresponding to the main cavities (31), and the center of the upper end ring groove (23) is provided with a dummy shaft hole (21); the lower mold (4) is provided with a lower end ring groove (41) corresponding to the main cavities (31), and the center of the lower end ring groove (41) is provided with a positioning groove (42); a rotor core (5) is placed in the main cavities (31), and the main cavities (31) are cylindrical holes and gap-fitted with the rotor core (5); the rotor core (5) is pressed from a plurality of punched sheets (51), and the lower opening of the shaft hole (512) of the punched sheet (51) is provided with a second protruding part (502); the lower opening of the bar slot (511) of the punched sheet (51) is provided with a first protruding part (501); a dummy shaft assembly (1) is placed in the dummy shaft hole (21), the dummy shaft assembly (1) passes through the shaft hole (512) in the middle of the rotor core (5), and the lower end of the dummy shaft assembly (1) is fitted with the positioning groove (42); an extrusion assembly (13) on the dummy shaft assembly (1) acts on the side surface of the shaft hole (512) to realize the positioning of the punched sheet (51) of the rotor core (5), and simultaneously closes the gap (50) formed between the punched sheets (51); the dummy shaft assembly (1) comprises a shaft cylinder (12) which is positioned and fitted with the upper mold (2) and the lower mold (4); a driving shaft (11) is slidably arranged in the middle of the shaft cylinder (12); the extrusion assembly (13) comprises a first extrusion part (15) and a second extrusion part (16) which are arranged in different directions; the driving shaft (11) is in transmission connection with the first extrusion part (15) and the second extrusion part (16); the first extrusion part (15) comprises a connecting rod structure, and the second extrusion part (16) comprises a wedge block structure; the shaft cylinder (12) is provided with a positioning block (14) which limits the moving direction of the driving shaft (11); the inclined end face formed by the first protruding part (501) and the hole wall of the bar slot (511), and the inclined end face formed by the second protruding part (502) and the hole wall of the shaft hole (512) all have an included angle with the vertical direction; the extrusion assembly (13) of the dummy shaft assembly (1) transversely extrudes the second protruding part (502) of the shaft hole (512) of the rotor core (5), and the transverse extrusion of the first protruding part (501) of the bar slot (511) of the rotor core (5) by the aluminum liquid delivered by the die-casting machine makes the gap (50) between the punched sheets (51) of the rotor core (5) have a closing trend; the upper end of the shaft cylinder (12) is provided with an upper positioning part (121) which is fitted with the dummy shaft hole (21) of the upper mold (2); the lower end of the shaft cylinder (12) is provided with a lower positioning part (122) which is fitted with the positioning groove (42) of the lower mold (4); the driving shaft (11) is provided with a limiting groove (113), and the positioning block (14) oppositely arranged on the shaft cylinder (12) is in clamping connection with the limiting groove (113). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The driving shaft (11) is connected with an external actuating mechanism at one end of the shaft cylinder (12), and the other end of the driving shaft (11) is provided with a first hinge shaft (111) and a first wedge block (112); The first hinge shaft (111) is connected with the connecting rod structure of the first extrusion part (15); The first wedge block (112) is connected with the wedge block structure of the second extrusion part (16); The connecting rod structure of the first extrusion part (15) comprises a driving rod (151) and a supporting rod (152); One end of the driving rod (151) is hingedly connected with the first hinge shaft (111) of the driving shaft (11), and the other end is hingedly connected in the middle of the supporting rod (152); One end of the supporting rod (152) is hingedly connected with the second hinge shaft (123) of the shaft cylinder (12), and the other end is drivingly connected with an extrusion block (153); The extrusion block (153) has an arc-shaped end face matched with the rotating shaft hole (512) of the rotor iron core (5); The other side of the arc-shaped end face of the extrusion block (153) is provided with a convex rib, and a plurality of waist-shaped holes (1531) are arranged on the convex rib; The end of the supporting rod (152) is provided with a sliding pin (1521) which is in sliding fit with the waist-shaped hole (1531); The middle of the supporting rod (152) is provided with a rotating shaft (1522) connected with the driving rod (151).

2. The aluminum rotor die-casting mold according to claim 1, characterized in that: A plurality of guide column holes (32) are arranged on the middle mold (3); An upper guide column (22) and a lower guide column (43) matched with the guide column holes (32) are respectively arranged on the upper mold (2) and the lower mold (4); A plurality of injection ports (44) in communication with the lower end ring grooves (41) are further arranged on the lower mold (4); A positioning boss (45) matched with the die-casting cylinder is arranged on the lower end of the lower mold (4).

3. The aluminum rotor die-casting mold according to claim 2, characterized in that: The first wedge block (112) is arranged symmetrically on both sides of the driving shaft (11); The wedge block structure of the second extrusion part (16) comprises a second wedge block (161) and a guide block (162); The second extrusion part (16) has an arc-shaped end face matched with the rotating shaft hole (512) of the rotor iron core (5), and the second wedge block (161) is arranged on the other side of the arc-shaped end face of the second extrusion part (16); The second wedge block (161) abuts against the first wedge block (112) of the driving shaft (11); The guide block (162) is provided with guide portions on both sides, and the guide portions are slidingly arranged in the guide groove (124) of the shaft cylinder (12).

4. A motor rotor made of the aluminum rotor die-casting mold according to any one of claims 1-3, characterized in that: The middle of the punching sheet (51) is provided with a rotating shaft hole (512), and a plurality of guide bar grooves (511) are arranged circumferentially on the punching sheet (51); The outer circular end face of the punching sheet (51) of the rotor iron core (5) is in clearance fit and positioning with the main cavity (31) of the middle mold (3). The extrusion assembly (13) of the mold clamped false shaft assembly (1) abuts the rotating shaft hole (512) of the lamination (51) of the rotor core (5) to form an inner circular end face.

5. The electric machine rotor of claim 4, wherein: The upper die pressing table (211) of the upper die (2) presses the upper part of the rotor core (5) after mold clamping; The lower die pressing table (421) of the lower die (4) abuts the lower part of the rotor core (5).

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