A rotor end ring hot extrusion device

Abstract

The present invention discloses a hot extrusion device for a rotor end ring, which comprises a hydraulic cylinder, an upper die core. A secondary extrusion cylinder is arranged inside the upper die core. A piston is arranged in the secondary extrusion cylinder. A piston rod is arranged on the piston. An oil inlet pipe is arranged above the piston. An oil storage pressure chamber is arranged between the piston and the bottom of the secondary extrusion cylinder. A connecting block is arranged at the lower part of the secondary extrusion cylinder. The ejector sleeve is fixedly connected with the secondary extrusion cylinder through a retaining collar. After the hydraulic cylinder performs the first die-casting process on the rotor, the secondary extrusion cylinder in the upper die core then drives the piston rod to descend, and pushes the extrusion column connected to the connecting block to perform secondary hot extrusion on the rotor end ring in a semi-solid state. The designed upper die core with an internal second cylinder can greatly improve the density and hardness of the end ring after forming, increase its tensile strength and conductivity, and at the same time reduce the pores and bubbles in the rotor end ring, improve the product qualification rate, reduce the die-casting cost of the enterprise, and facilitate the enterprise to conduct market competition.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing motor rotors, and particularly to a hot extrusion device for rotor end rings. Background Art

[0002] Currently, the equipment for die-casting motor rotor end rings is usually for one-time die-casting. The advantage of this one-time die-casting forming device is that the processing procedures are few, but there are many defects in the rotor end rings formed by one-time die-casting in actual applications. Due to the diverse shapes of rotor end rings, for relatively complex end rings, only through one-time die-casting, there are often many pores and bubbles on the surface or inside, reducing the product qualification rate and increasing the production cost of enterprises. In addition, the current increase in the motor speed has higher requirements for the tensile strength and conductivity of the rotor end rings. The rotor end rings formed by one-time die-casting usually have low density and small hardness, and are prone to phenomena such as fracture and ring dropping in actual applications, affecting the induced current of the motor and unable to meet the performance requirements of the motor. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the present invention provides a device capable of hot extruding the rotor end ring in a semi-solid state after die-casting.

[0004] The technical solution adopted by the present invention is: a hot extrusion device for rotor end rings, the device includes a hydraulic cylinder, an upper die core connected to the hydraulic cylinder, an upper die coaxial with the upper die core is arranged below the upper die core, the upper die is fixedly connected to the middle of the upper die support frame, and a lower die is arranged below the upper die; characterized in that: a secondary extrusion cylinder is arranged inside the upper die core, a piston is arranged in the secondary extrusion cylinder, a piston rod is arranged on the piston, an oil inlet pipe is arranged above the piston, a storage oil pressure chamber is arranged between the piston and the bottom of the secondary extrusion cylinder, and an oil outlet pipe communicated with the storage oil pressure chamber is arranged on the side of the storage oil pressure chamber; a connecting block is arranged below the secondary extrusion cylinder, the upper part of the connecting block is connected to the piston rod, and the lower part of the connecting plate is connected to a top-out sleeve through an extrusion column; the top-out sleeve is fixedly connected to the secondary extrusion cylinder through a clamping sleeve.

[0005] Further, the outer diameter of the upper die core is equal to the inner diameter of the upper die.

[0006] Further, the piston rod penetrates through the piston up and down, and the piston rod and the piston are of an integral structure.

[0007] Further, a groove chamber is opened on the upper surface of the piston, and the groove chamber is communicated with the oil inlet pipe.

[0008] Preferably, an oil guiding inclined port is arranged on the outer edge of the groove chamber, and the oil inlet pipe is arranged at the oil guiding inclined port of the groove chamber.

[0009] Further, the oil storage pressure chamber has a stepped structure with a narrow upper chamber and a wide lower chamber, and the oil outlet pipe is arranged on the side of the lower chamber of the oil storage pressure chamber.

[0010] Further, the connecting block includes a first connecting block, a second connecting block and a third connecting block arranged in sequence from top to bottom. The first connecting block is fixedly connected to the lower part of the piston rod. The first connecting block is fixed to the second connecting block and the third connecting block through connecting columns. The extrusion column is arranged on the third connecting block, and the third connecting block is connected to the ejection sleeve through the extrusion column.

[0011] Further, a positioning column is vertically arranged at the center of the lower die, and the positioning column is fixedly connected to the lower die through a trapezoidal card slot.

[0012] Still further, the upper end of the positioning column has a frustum structure with a small-diameter surface facing upwards.

[0013] Compared with the prior art, the present invention designs a built-in secondary extrusion oil cylinder in the upper die core below the hydraulic oil cylinder, which can perform secondary hot extrusion in the semi-solid state after the rotor end ring is die-cast. Compared with the traditional one-time die-casting process, the hot extrusion device of the present invention can greatly improve the density and hardness of the rotor end ring without secondary die-casting, and increase the tensile strength and conductivity of the end ring. In addition, in industrial production, the setting of hot extrusion can effectively reduce the bubbles and pores in the end ring, improve the quality of the formed rotor end ring, ensure the product qualification rate of the die-cast parts, and is beneficial to saving the die-casting cost of the enterprise for market competition. On the other hand, the formed rotor with the die-cast end ring of the present invention has a strong tensile strength and excellent conductivity, and can improve the speed of the motor in practical applications, meet its performance requirements and make the motor have a longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0015] Figure 2 is a schematic diagram of the structure of the upper die core of the present invention;

[0016] Figure 3 is a schematic diagram of the structure of the connecting block of the present invention:

[0017] Figure 4 is a schematic diagram of the structure of the upper die support frame of the present invention (a is the vacuum channel); DETAILED DESCRIPTION OF THE INVENTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] As Figure 1 shown, a rotor end ring hot extrusion device includes a hydraulic cylinder 1 and an upper die core 2 connected to the hydraulic cylinder 1. Below the upper die core 2, an upper die 3 coaxial with it is provided. The upper die 3 is fixedly connected to the middle of an upper die support frame 4, and a lower die 5 is provided below the upper die 3.

[0020] As Figure 2 shown, a secondary extrusion cylinder 20 is arranged inside the upper die core 2. A piston 21 is arranged in the secondary extrusion cylinder 20. A piston rod 22 is arranged on the piston 21. An oil inlet pipe 23 is arranged above the piston 21. An oil storage pressure chamber 24 is arranged between the piston 21 and the bottom of the secondary extrusion cylinder 20. An oil outlet pipe 25 communicating with it is arranged on the side of the oil storage pressure chamber 24. A connecting block 26 is arranged at the lower part of the secondary extrusion cylinder 20. The upper part of the connecting block 26 is connected to the piston rod 22, and the lower part of the connecting plate 26 is connected to an ejector sleeve 28 through an extrusion column 27. The ejector sleeve 28 is fixedly connected to the secondary extrusion cylinder 20 through a retaining sleeve 29.

[0021] Furthermore, the outer diameter of the upper die core 2 is equal to the inner diameter of the upper die 3.

[0022] The piston rod 22 passes through the piston 21 up and down, and the piston rod 22 and the piston 21 are of an integral structure. An oil guiding inclined port is arranged on the outer edge of the groove chamber 211, and the oil inlet pipe 23 is arranged at the oil guiding inclined port of the groove chamber 211. The oil guiding inclined port is conducive to the rapid oil supply of the oil inlet pipe 23 and provides sufficient hydraulic oil pressure for the downward movement of the piston 21 and the piston rod 22.

[0023] Preferably, the oil storage pressure chamber 24 has a stepped structure with a narrow upper chamber and a wide lower chamber, and the oil outlet pipe 25 is arranged on the side of the lower chamber of the oil storage pressure chamber 24. The chamber structure with a narrow upper part and a wide lower part can provide an oil storage space and sufficient downward stroke for the piston rod 22 without affecting the extraction of hydraulic oil from the oil outlet pipe 23.

[0024] As Figure 3As shown, the connecting block 26 includes a first connecting block 26a, a second connecting block 26b, and a third connecting block 26c arranged in sequence from top to bottom. The first connecting block 26a is fixedly connected to the lower part of the piston rod 22. The first connecting block 26a is fixed to the second connecting block 26b and the third connecting block 26c by 4 connecting columns 26d. The extrusion column 27 is arranged on the third connecting block 26c. The third connecting block 26c is connected to the ejector sleeve 28 by 10 extrusion columns 27. It should be noted that the above-mentioned extrusion columns 27 and connecting columns 26d are not fixed at 4 and 10. In actual production, the number of columns can be increased or decreased according to the die-casting requirements.

[0025] Preferably, a positioning column 6 is vertically arranged at the center of the lower die 5. The positioning column 6 is fixedly connected to the lower die 5 through a trapezoidal card slot. The upper end of the positioning column 6 is a frustum structure with a small diameter facing upwards. The bottom diameter of the frustum is equal to the inner diameter of the ejector sleeve 28. The positioning column 6 is used to fix rotor cores of different heights.

[0026] As Figure 4 shown, a vacuum pipeline a for exhaust is also provided in the upper die 3 and the upper die support frame 4. The vacuum pipeline a evacuates the die-casting cavity before die-casting and continues to work after the lower die core 2 is pressed down, for extracting the residual gas from the outer wall of the lower die core 2, the inner wall of the upper die 3, and the pressure chamber, so as to keep the die-casting cavity in a vacuum state all the time.

[0027] The die-casting of the rotor end ring in the present invention can be summarized into two processes. First, the hydraulic cylinder 1 drives the entire upper die core 2 to perform the first die-casting on the rotor. Subsequently, the second oil cylinder 20 in the upper die core 2 starts to work. The oil inlet pipeline 23 supplies oil downward to push the piston rod 22 of the piston 21 to move downward. The bottom of the piston rod 22 then drives the lower connecting block 26 to move downward. The extrusion columns 27 in the ejector sleeve 28 are pressured by the connecting block 26c to perform secondary hot extrusion on the semi-solidified end ring. After the hot extrusion is completed, the hydraulic oil in the oil storage pressure chamber 24 is withdrawn from the oil outlet pipeline 25, and the extrusion columns 27, the connecting block 26, the piston 21, and the piston rod 22 return to their original positions. During the entire die-casting process, the vacuum pipeline a provided in the upper die 3 and the upper die support frame 4 continues to work to ensure that the die-casting cavity is in a vacuum state, cooperating with the die-casting and hot extrusion procedures to greatly improve the density and hardness of the formed rotor end ring, increase its tensile strength and conductivity, save costs for the enterprise, and ensure the product qualification rate of the die-cast parts.

Claims

1. A rotor end ring hot extrusion device, which comprises a hydraulic cylinder (1), an upper die core (2) connected to the hydraulic cylinder (1), an upper die (3) coaxial with the upper die core (2) is arranged below the upper die core (2), the upper die (3) is fixedly connected to the middle of an upper die support frame (4), and a lower die (5) is arranged below the upper die (3); characterized in that: Inside the upper die core (2), a secondary extrusion oil cylinder (20) is provided. A piston (21) is arranged in the secondary extrusion oil cylinder (20). A piston rod (22) is arranged on the piston (21). An oil inlet pipe (23) is arranged above the piston (21). A storage oil pressure chamber (24) is arranged between the piston (21) and the bottom of the secondary extrusion oil cylinder (20). An oil outlet pipe (25) communicating with the storage oil pressure chamber (24) is arranged on the side of the storage oil pressure chamber (24). A connecting block (26) is arranged at the lower part of the secondary extrusion oil cylinder (20). The upper part of the connecting block (26) is connected to the piston rod (22). The lower part of the connecting block (26) is connected to an ejection sleeve (28) through an extrusion column (27). The ejection sleeve (28) is fixedly connected to the secondary extrusion oil cylinder (20) through a ferrule (29). The outer diameter of the upper die core (2) is equal to the inner diameter of the upper die (3). The piston rod (22) passes through the piston (21) vertically up and down, and the piston rod (22) and the piston (21) are of an integral structure. The connecting block (26) includes a first connecting block (26a), a second connecting block (26b) and a third connecting block (26c) arranged in sequence from top to bottom. The first connecting block (26a) is fixedly connected to the lower part of the piston rod (22). The first connecting block (26a), the second connecting block (26b) and the third connecting block (26c) are fixed through a connecting column (26d). The extrusion column (27) is arranged on the third connecting block (26c). The third connecting block (26c) is connected to the ejection sleeve (28) through the extrusion column (27).

2. The rotor end ring hot extrusion device according to claim 1, characterized in that: A groove chamber (211) is formed on the upper surface of the piston (21), and the groove chamber (211) communicates with the oil inlet pipe (23).

3. The end ring hot extrusion device according to claim 2, wherein: An oil guiding inclined opening is arranged on the outer edge of the groove chamber (211), and the oil inlet pipe (23) is arranged at the oil guiding inclined opening of the groove chamber (211).

4. A kind of end ring hot extrusion device according to claim 1, characterized in that: The storage oil pressure chamber (24) has a stepped structure with a narrow upper chamber and a wide lower chamber, and the oil outlet pipe (25) is arranged on the side of the lower chamber of the storage oil pressure chamber (24).

5. A rotor end ring hot extrusion device according to claim 1, characterized in that: A positioning column (6) is vertically arranged at the center of the lower die (5), and the positioning column (6) is fixedly connected to the lower die (5) through a trapezoidal card slot.

6. The rotor end ring hot extrusion device according to claim 5, characterized in that: The upper end of the positioning column (6) is a frustum structure with a small-diameter surface facing up.

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