Five-station cold extrusion manufacturing method for automotive motor shafts

Abstract

The present invention provides a five-station cold extrusion method for manufacturing automotive motor shafts. Through cold extrusion using five dies, the motor shafts can be directly produced. This method improves raw material utilization and quality, enhances production efficiency, and achieves high-quality appearance and product strength.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-station cold heading, and in particular to a method for manufacturing a motor shaft for a vehicle. Background Art

[0002] The motor shaft is a cylindrical component that extends from the motor and its housing. The shaft is the main support and connection part of the armature part of the motor. It is also the output part of the power generated by the motor. The purpose of the shaft is to convert the energy of the motor into the final use. The precision pin and the motor shaft are used to provide the speed and torque of the motor. It is one of the important and indispensable parts of the motor.

[0003] The automotive motor shaft manufactured by the present invention has an external structure including a rod body, which is divided into two parts, front and rear, by a raised ring. The front part is longer and the rear part is shorter, and the rear part is 55-65% of the length of the front part. The front and rear parts are both two cylindrical rods, which are named as the first rod, the second rod, the third rod and the fourth rod from back to front respectively. The raised ring is located between the second rod and the third rod. The four rods have different diameters, and are, from largest to smallest, the third rod, the second rod, the first rod and the fourth rod. The four rods have different lengths, and are, from largest to smallest, the third rod, the first rod, the second rod and the fourth rod; the diameter of the third rod is 60-70% of the diameter of the raised ring, the diameter of the second rod is slightly smaller than that of the third rod, the diameter of the fourth rod is slightly smaller than that of the first rod, and the diameter of the fourth rod is 45%-55% of the diameter of the third rod.

[0004] The above-mentioned automotive motor shafts are currently mainly produced through machining or hot forging followed by machining. This process has problems such as low product precision, poor stability, high material loss, long production cycle, and low efficiency. The comprehensive performance can no longer meet the needs of the domestic and foreign automotive manufacturing industries. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for manufacturing a motor shaft for an automobile, which can directly produce the motor shaft for an automobile through a multi-station cold extrusion method, thereby improving the utilization rate and quality of raw materials and enhancing production efficiency. To this end, the present invention adopts the following technical solutions:

[0006] A five-station cold extrusion manufacturing method for a motor shaft for an automobile, wherein the outer structure of the motor shaft for an automobile includes a rod body, which is divided into two parts, front and rear, by a raised ring. The front part is longer and the rear part is shorter, and the rear part is 55-65% of the length of the front part. The front and rear parts are both two cylindrical rods, which are named as the first rod, the second rod, the third rod and the fourth rod from back to front, respectively. The raised ring is located between the second rod and the third rod. The four rods have different diameters, and are, from large to small, the third rod, the second rod, the first rod and the fourth rod. The four rods have different lengths, and are, from large to small, the third rod, the first rod, the second rod and the fourth rod; the diameter of the third rod is 60-70% of the diameter of the raised ring, the second rod is slightly smaller than the diameter of the third rod, the diameter of the fourth rod is slightly smaller than the diameter of the first rod, and the diameter of the fourth rod is 45%-55% of the diameter of the third rod; characterized in that

[0007] The manufacturing method comprises the following steps:

[0008] (1) Feeding the coil into a cold heading machine and automatically shearing it into individual raw material pieces of the automotive motor shaft, wherein the diameter of the coil is close to the diameter of the third rod, and the length of the raw material piece is shorter than the total length of the automotive motor shaft;

[0009] (2) The raw material is transferred into the No. 1 mold port of the cold heading forming machine, and is cold headed in the No. 1 mold so that the front end and the rear end of the No. 1 molded product are formed into conical surfaces;

[0010] (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the front and rear ends of the molded product No. 2 are both tied with rods, the tie-rod ratio of the front end is larger than that of the rear end, and the length of the tie-rod section of the rear end is longer than that of the first section of the rod, the diameter after the tie-rod is consistent with the diameter of the second section of the rod, and the length of the tie-rod section of the front end is shorter than that of the fourth section of the rod; the length of the rod body without tie-rod is longer than that of the third section of the rod but shorter than the total length of the second and third sections of the rod;

[0011] (4) The molded product No. 2 is translated to the mouth of the mold No. 3, and after cold heading in the mold No. 3, the front end beam segment of the molded product No. 2 is further beamed, and the rear end beam segment of the rear end beam segment of the molded product No. 2 is further beamed; wherein, the beam ratio of the rear end of the molded product No. 3 is larger than that of the front end, and the diameter after beaming is between the diameter of the first beam segment and the diameter of the second beam segment, and the rear unbundled segment constitutes the second beam segment, and the diameter of the front end beam segment of the molded product No. 3 is larger than the diameter of the fourth beam segment;

[0012] (5) The finished product of mold No. 3 is translated to the mouth of mold No. 4, and after cold heading in mold No. 4, the front end beam segment of the finished product of mold No. 3 is further beamed to form the fourth beam segment, and the rear end beam segment of the finished product of mold No. 3 is further beamed to form the first beam segment;

[0013] (6) The finished product of mold No. 4 is translated to the opening of mold No. 5, wherein the mold surface line of mold No. 5 corresponds to the front end surface of the raised circular ring, so that the untied rod portion of the finished product of mold No. 2 is located in the front mold to form the third section of the rod, and the untied rod portion of the finished product of mold No. 2 is located in the main mold, and the raised circular ring is upset to form the motor shaft for the vehicle.

[0014] Furthermore, for the front end beam ratio, the beam ratio of the finished product of mold No. 2, the beam ratio of mold No. 3, and the beam ratio of mold No. 4 decrease in sequence; for the rear end beam ratio, the beam ratio of mold No. 3 is the largest, the beam ratio of mold No. 2 is the second largest, and the beam ratio of mold No. 4 is smaller than that of mold No. 2.

[0015] The present invention can use five-station cold extrusion molding technology to form automotive motor shafts in one go through a reasonable arrangement of workstation tasks. The product has a smooth appearance, stable quality, is more solid in structure, is safe to use, and has a strong load-bearing capacity. The manufacturing method of the present invention reduces the lathe allowance, which greatly reduces the loss of raw materials. The process of the present invention reduces the tedious process of blanking and lathe repair, and reduces the production process by 3 steps. The present invention can be produced through five-station cold heading continuous molding, with a high production speed. The daily production capacity is increased from the original machining of 50Pcs / day / unit / person to 11520Pcs / day / unit / person, and the molding efficiency is increased by 230.4 times. The average daily output far exceeds that of the past, greatly improving production efficiency and greatly reducing the investment cost of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the process flow of the manufacturing method of the present invention. DETAILED DESCRIPTION

[0017] Referring to the accompanying drawings, the automotive motor shaft 100 to be manufactured by the present invention has an external structure including a rod body, which is divided into two parts, front and rear, by a raised ring 50. The front part is longer and the rear part is shorter, and the rear part is 55-65% of the length of the front part. The front and rear parts are both two cylindrical rods, which are named from back to front as the first rod 51, the second rod 52, the third rod 53 and the fourth rod 54, respectively. The raised ring 50 is located between the second rod 52 and the third rod 53. The diameters of the four rods are different, and from large to small they are the third rod 53, the second rod 52, the first rod 5 1 and a fourth section rod 54, the lengths of the four sections are different, and from largest to smallest they are the third section rod 53, the first section rod 51, the second section rod 52 and the fourth section rod 54; the diameter of the third section rod 53 is 60-70% of the diameter of the raised ring 50, the second section rod 52 is slightly smaller than the diameter of the third section rod 53, the diameter of the fourth section rod 54 is slightly smaller than the diameter of the first section rod 51, and the diameter of the fourth section rod 54 is 45%-55% of the diameter of the third section rod; the diameter difference between the second section rod 52 and the first section rod 51 is greater than the diameter difference between the first section rod 51 and the fourth section rod 54.

[0018] The five-station cold extrusion manufacturing method uses a coil material to first heat-treat and spheroidize, then perform a phosphate surface treatment, fine drawing and sizing treatment, and then perform the following steps of cold extrusion manufacturing:

[0019] (1) The coil is fed into a cold heading machine and automatically cut into individual automotive motor shaft raw materials 101. The diameter of the coil is consistent with the diameter of the third rod 53. The length of the raw material 101 is shorter than the total length of the automotive motor shaft 100.

[0020] (2) The raw material is transferred into the No. 1 mold port of the cold heading forming machine, and is cold headed in the No. 1 mold so that the rear end and the front end of the No. 1 molded product are formed with conical surfaces 11 and 12, which is beneficial for the subsequent rod binding;

[0021] (3) The molded product 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the front and rear ends of the molded product 2 are both bound by rods. The bound-rod ratio of the front end is larger than that of the rear end. In this embodiment, the bound-rod ratio of the front end is 35.8%, and the bound-rod ratio of the rear end is 18.6%. The bound-rod ratio is (1-diameter after the bound-rod / diameter before the bound-rod)*100, the same below.

[0022] In addition, the length of the rear end tie rod section 21 is longer than the first section rod 51, the diameter after the tie rod is tied (that is, the diameter of the rear end tie rod section 21) is consistent with the diameter of the second section rod 52 (subsequently, at most there is only a slight difference naturally caused by the sleeve mold), and the length of the front end tie rod section 22 is shorter than the fourth section rod 54; the length of the untied rod body 20 is longer than the third section rod 53 but shorter than the total length of the second section rod 52 and the third section rod 53.

[0023] The tied rod section and the untied rod section are transitioned through a transition surface.

[0024] In the subsequent cold extrusion process, the metal flow transfer amount to form the raised ring 50 comes from the rear part of the untied rod body 20, the metal flow transfer amount to form the first section rod 51 comes from the rear part of the rear end tied rod segment 21, and the metal flow transfer amount to form the fourth section rod 54 comes from the front end tied rod segment 22, which can reduce the metal flow transfer amount and transfer distance, help reduce the difficulty and improve the appearance quality.

[0025] (4) The molded product No. 2 is translated to the mouth of the mold No. 3, and after cold heading in the mold No. 3, the front end tie rod segment 22 of the molded product No. 2 is further tied to form the front end tie rod segment 32 of the molded product No. 3, and the front end tie rod segment 21 of the molded product No. 2 is further tied to form the rear end tie rod segment 31 of the molded product No. 3, wherein the tie rod ratio of the rear end of the molded product No. 3 is 30%, and the tie rod ratio of the front end of the molded product No. 3 is 25.4%. The diameter of the rear end tie rod segment 31 of the molded product No. 3 is between the diameter of the first section rod 51 and the diameter of the second section rod 52, and the rear untied section constitutes the second section rod 52 (subsequently, at most there is a slight difference caused by the natural die), and the diameter of the front end tie rod segment 32 of the molded product No. 3 is larger than the diameter of the fourth section rod 54. During the cold heading manufacturing process of the No. 3 die, the unbound rod body 20 in the No. 2 die product 2 basically does not generate metal flow, and at most there is only a slight difference caused naturally by the die.

[0026] (5) The finished product 3 of mold No. 3 is translated to the mouth of mold No. 4 and cold-forged in mold No. 4. The rear end tie rod segment 31 of the finished product 3 of mold No. 3 is further tied to form the fourth section 54, with a tie rod ratio of 16.8%. The rear end tie rod segment 31 of the finished product 3 of mold No. 3 is further tied to form the first section 51, with a tie rod ratio of 15.6%. During the cold-forging process of mold No. 4, the untied rod body 20 of the finished product 2 of mold No. 2 generates substantially no metal flow, and at most there is only a slight difference caused by the natural formation of the die.

[0027] (6) The molded product 4 is translated to the mold opening of the mold No. 5, wherein the mold surface line of the mold No. 5 corresponds to the front end surface 501 of the raised ring 50, so that the untied rod portion 20 of the molded product 2 is located in the front mold and constitutes the third section of the rod 53. The untied rod portion 20 of the molded product 2 is located in the main mold and is upset to form the raised ring 50. The amount of metal transferred is very small, the transfer distance is short, and there is no difficulty in demolding. The appearance quality of the rod body is good and the product strength is high; the automotive motor shaft 100 is manufactured.

[0028] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the field of the present invention are included in the protection scope of the present invention.

Claims

1. A five-station cold extrusion manufacturing method for a motor shaft for an automobile, wherein the outer structure of the motor shaft for an automobile includes a rod body, which is divided into two parts, front and rear, by a raised ring. The front part is longer and the rear part is shorter, and the rear part is 55-65% of the length of the front part. The front and rear parts are both two cylindrical rods, which are named as the first rod, the second rod, the third rod and the fourth rod from back to front, respectively. The raised ring is located between the second rod and the third rod. The four rods have different diameters, and are, from large to small, the third rod, the second rod, the first rod and the fourth rod. The four rods have different lengths, and are, from large to small, the third rod, the first rod, the second rod and the fourth rod; the diameter of the third rod is 60-70% of the diameter of the raised ring, the second rod is smaller than the diameter of the third rod, the diameter of the fourth rod is smaller than the diameter of the first rod, and the diameter of the fourth rod is 45%-55% of the diameter of the third rod; characterized in that The manufacturing method comprises the following steps: (1) Feeding the coil into a cold heading machine and automatically shearing it into individual raw material pieces of the automotive motor shaft, wherein the diameter of the coil is consistent with the diameter of the third rod, and the length of the raw material piece is shorter than the total length of the automotive motor shaft; (2) The raw material is transferred into the No. 1 mold port of the cold heading forming machine, and is cold headed in the No. 1 mold so that the front end and the rear end of the No. 1 molded product are formed into conical surfaces; (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the front and rear ends of the molded product No. 2 are both tied with rods, the tie-rod ratio of the front end is larger than that of the rear end, and the length of the tie-rod section of the rear end is longer than that of the first section of the rod, the diameter after the tie-rod is consistent with the diameter of the second section of the rod, and the length of the tie-rod section of the front end is shorter than that of the fourth section of the rod; the length of the rod body without tie-rod is longer than that of the third section of the rod but shorter than the total length of the second and third sections of the rod; (4) The molded product No. 2 is translated to the mouth of the mold No. 3, and after cold heading in the mold No. 3, the front end beam segment of the molded product No. 2 is further beamed, and the rear end beam segment of the rear end beam segment of the molded product No. 2 is further beamed; wherein, the beam ratio of the rear end of the molded product No. 3 is larger than that of the front end, and the diameter after beaming is between the diameter of the first beam segment and the diameter of the second beam segment, and the rear unbundled segment constitutes the second beam segment, and the diameter of the front end beam segment of the molded product No. 3 is larger than the diameter of the fourth beam segment; (5) The finished product of mold No. 3 is translated to the mouth of mold No. 4, and after cold heading in mold No. 4, the front end beam segment of the finished product of mold No. 3 is further beamed to form the fourth beam segment, and the rear end beam segment of the finished product of mold No. 3 is further beamed to form the first beam segment; (6) The finished product of mold No. 4 is translated to the opening of mold No. 5, wherein the mold surface line of mold No. 5 corresponds to the front end surface of the raised circular ring, so that the untied rod portion of the finished product of mold No. 2 is located in the front mold to form the third section of the rod, and the untied rod portion of the finished product of mold No. 2 is located in the main mold, and the raised circular ring is upset to form the motor shaft for the vehicle.

2. The five-station cold extrusion manufacturing method for a motor shaft for a vehicle according to claim 1, characterized in that For the front end beam, the beam ratio of the product made by mold No. 2, mold No. 3 and mold No. 4 decreases in sequence; for the rear end beam, the beam ratio of mold No. 3 is the largest, followed by mold No. 2, and the beam ratio of mold No. 4 is smaller than that of mold No. 2.

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