A cold heading method for manufacturing air conditioner crankshaft blank

Abstract

The invention relates to a method for manufacturing a crankshaft blank, and specifically to a cold heading method for manufacturing an air-conditioning crankshaft blank. The method realizes the manufacturing of the air-conditioning crankshaft blank by performing multiple cold headings on a cold heading steel cylinder. The method saves materials and has low cost. In addition, the cold heading method does not require heating, so the material properties of the cold heading steel cylinder will not be changed, thereby ensuring the performance of the material and avoiding subsequent other treatments on the material to increase the complexity of the subsequent process.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a crankshaft, in particular to a cold heading method for manufacturing an air conditioner crankshaft blank. Background Art

[0002] The crankshaft is a key component of the rotary air-conditioning compressor and has high performance requirements. The conventional solution is to produce the crankshaft blank by mold casting and then machine it into shape, or simply produce it from rods through machining.

[0003] The production process from mold manufacturing to product manufacturing is very complicated when casting is used. In addition, due to the inevitable generation of pores and slag inclusion defects in the product, the scrap rate is high. At the same time, a large amount of margin needs to be left for the casting blank, which is then processed through multiple steps. The material utilization rate is low, the processing steps are complicated, and the production efficiency is low. In addition, the casting process consumes a lot of energy, produces a lot of dust, and is easy to pollute the environment.

[0004] When machining rods, on the one hand, the amount of cutting is relatively large, and the performance of the material cannot be fully utilized; on the other hand, machining of slender holes is also a problem; in addition, compared with casting, the cost is relatively high.

[0005] Therefore, there is an urgent need for a method with a short process, low energy consumption, environmental friendliness, and the ability to fully utilize the material properties of the profile to achieve the production of air-conditioning crankshafts, which has become an urgent problem that researchers in this field need to solve. Summary of the invention

[0006] The technical problem to be solved by the present invention is: how to realize a method for manufacturing an air conditioner crankshaft blank which can achieve a short process, low energy consumption, environmental friendliness, and fully utilize the performance of profile materials.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] The present invention is a cold heading method for manufacturing an air conditioner crankshaft blank, comprising the following steps:

[0009] Step S1: Select steel suitable for cold heading processing, and cut out a cold heading steel cylinder of appropriate length according to the specifications of the air-conditioning compressor crankshaft;

[0010] Step S2: cold forging a positioning hole on one end surface of the cold forging steel cylinder to form a first cold forging blank;

[0011] Step S3: performing cold heading along the axial direction of the positioning hole of the first cold heading blank to form a second cold heading blank having a second axial hole;

[0012] Step S4: cold heading and reducing the inner diameter and outer diameter of the second axial hole of the second cold heading blank to form a third cold heading blank having a main shaft section and a large diameter section in the axial direction, wherein the main shaft section has a third axial hole formed by reducing the diameter of the second axial hole;

[0013] Step S5: cold heading and reducing the diameter of the large diameter section at the other end of the third cold heading blank to form a fourth cold heading blank having a main shaft section, a middle section and a first secondary shaft section in the axial direction;

[0014] Step S6: cold heading the fourth cold-headed blank again to form the cold-headed crankshaft blank having a main shaft section, an eccentric portion and a second secondary shaft section.

[0015] Furthermore, in step S6, it also includes:

[0016] Step S61: performing secondary cold heading and diameter reduction on the first secondary shaft section of the fourth cold heading blank to form a fifth cold heading blank having a main shaft section, an intermediate section and a second secondary shaft section.

[0017] Furthermore, in step S6, it also includes:

[0018] Step S62: cold heading the middle section and / or the first auxiliary shaft section of the fourth cold heading blank or the fifth cold heading blank to form a sixth cold heading blank having a main shaft section, a burr eccentric portion and a second auxiliary shaft section;

[0019] Step S63: removing burrs on the eccentric portion of the burr of the sixth cold-headed blank to form an eccentric portion.

[0020] Further, in step S2, the outer diameter of the first cold heading blank is consistent with the outer diameter of the cold heading steel cylinder, and the axis of the positioning hole is colinear with the axis of the first cold heading blank.

[0021] Furthermore, in step S3, the axial length of the second axial hole is greater than the axial length of the positioning hole, the inner diameter of the second axial hole is consistent with the inner diameter of the positioning hole, and the length of the second cold-headed blank (2) is greater than the length of the first cold-headed blank.

[0022] Further, in step S4, the inner diameter of the third axial hole is smaller than the inner diameter of the second axial hole, and the axial length of the third axial hole is greater than the axial length of the second axial hole;

[0023] The third cold heading blank has a front main shaft section, a rear large diameter section, and a first transition section connecting the main shaft section and the large diameter section. The outer diameter of the large diameter section is consistent with the outer diameter of the second cold heading blank, and the outer diameter of the main shaft section is smaller than the outer diameter of the large diameter section.

[0024] Further, in step S5, the first secondary shaft section and the main shaft section are respectively located on both sides of the middle section, and a second transition section is provided between the first secondary shaft section and the middle section;

[0025] The outer diameter of the middle section is consistent with the outer diameter of the large diameter section, the outer diameter of the first auxiliary shaft section is smaller than the outer diameter of the middle section, and the sum of the axial lengths of the first auxiliary shaft section, the middle section and the second transition section is greater than the axial length of the large diameter section.

[0026] Further, in step S6, the outer diameter of the second auxiliary shaft section is smaller than the outer diameter of the first auxiliary shaft section, the outer diameter of the eccentric portion is larger than the outer diameter of the middle section, and the axial length of the eccentric portion is smaller than the sum of the axial lengths of the middle section, the first transition section, and the second transition section.

[0027] Further, in step S61, the middle section of the fifth cold heading blank has the same axial length and outer diameter as the middle section of the fourth cold heading blank, the axial length of the second secondary shaft section arranged at the end of the rear section of the fifth cold heading blank is greater than the axial length of the first secondary shaft section, the outer diameter of the second secondary shaft section is smaller than the outer diameter of the first secondary shaft section, the axial length of the third transition section arranged between the middle section of the fifth cold heading blank and the main shaft section is smaller than the axial length of the first transition section, and the axial length of the fourth transition section arranged between the middle section of the fifth cold heading blank and the second secondary shaft section is greater than the axial length of the second transition section;

[0028] Further, in step S62, the outer diameter of the burr eccentric portion is greater than the outer diameter of the middle section, and the axial length of the burr eccentric portion is less than the sum of the axial lengths of the middle section, the third transition section, and the fourth transition section;

[0029] In step S63, the outer diameters of the eccentric portion and the burr eccentric portion are consistent.

[0030] Furthermore, in step S1, the material of the cold heading steel cylinder is 40Cr, 20Cr, or 45 steel.

[0031] Beneficial effects of the present invention: The present invention is a cold heading method for manufacturing an air-conditioning crankshaft blank. The method realizes the manufacturing of the air-conditioning crankshaft blank by multiple cold heading of a cold heading steel cylinder. The method saves materials and has low cost. In addition, no heating is required by cold heading, so the material properties of the cold heading steel cylinder will not be changed, thereby ensuring the performance of the material and avoiding subsequent other processing of the material to increase the complexity of the subsequent process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] Figure 1 It is a schematic diagram of the structure of a cold-headed steel cylinder;

[0034] Figure 2 is a schematic diagram of the structure of the first cold heading blank;

[0035] Figure 3 Schematic diagram of the structure of the second cold heading blank;

[0036] Figure 4 It is a schematic diagram of the structure of the third cold heading blank;

[0037] Figure 5 is a schematic diagram of the structure of the fourth cold heading blank;

[0038] Figure 6 is a structural schematic diagram of the fifth cold heading blank;

[0039] Figure 7 It is a structural schematic diagram of the sixth cold heading blank with a burr eccentric portion;

[0040] Figure 8 is a three-dimensional schematic diagram of the sixth cold-forged blank with a burr eccentric portion;

[0041] Fig. 9 It is a structural schematic diagram of a cold-forged crankshaft blank;

[0042] Fig.10 It is a three-dimensional schematic diagram of a cold-forged crankshaft blank;

[0043] In the figure: 01-cold heading steel cylinder, 1-first cold heading blank, 11-positioning hole, 2-second cold heading blank, 21-second axial hole, 3-third cold heading blank, 31-third axial hole, 32-main shaft section, 33-large diameter section, 34-first transition section, 4-fourth cold heading blank, 41-first secondary shaft section, 42-middle section, 43-second transition section, 5-fifth cold heading blank, 51-second secondary shaft section, 52-third transition section, 53-fourth transition section, 6-sixth cold heading blank, 61-burr eccentric part, 62-burr, 7-cold heading crankshaft blank, 71-eccentric part. DETAILED DESCRIPTION

[0044] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0045] first, Figure 3 The left part of the second cold heading blank 2 is defined as the front section, the right part is defined as the rear section, and the part between the front section and the rear section is defined as the middle section. Example 1

[0046] The present invention is a cold heading method for manufacturing an air conditioner crankshaft blank, comprising the following steps:

[0047] like Figure 1 As shown, step S1: select a profile, wire or bar suitable for cold heading processing, the material can be 40Cr, 20Cr, 45 steel, 40Cr in this embodiment, and cut out a cold heading steel cylinder 01 of appropriate length according to the specifications of the air-conditioning compressor crankshaft.

[0048] like Figure 2 As shown, step S2: on the end surface of the cold-forged steel cylinder 01, that is, Figure 2 A positioning hole 11 is cold-forged on the left end surface to form a first cold-forged blank 1; wherein the outer diameter of the first cold-forged blank 1 is consistent with the outer diameter of the cold-forged steel cylinder 01, and the axis of the positioning hole 11 is colinear with the axis of the first cold-forged blank 1; the role of the cold-forged positioning hole 11 is to facilitate accurate positioning during the subsequent cold forging of the second axial hole 21.

[0049] like Figure 3 As shown, step S3: cold heading is performed axially along the positioning hole 11 of the first cold heading blank 1 to form a second cold heading blank 2 with a second axial hole 21; wherein the axial length of the second axial hole 21 is greater than the axial length of the positioning hole 11, the inner diameter of the second axial hole 21 is consistent with the inner diameter of the positioning hole 11, and the length of the second cold heading blank 2 is greater than the length of the first cold heading blank 1.

[0050] On the basis of step S2, a second axial hole 21 is cold-forged along the positioning hole 11, and the axial length of the second axial hole 21 is greater than the axial length of the positioning hole 11 in S2. At the same time, the second cold-forged blank 2 is elongated so that the length of the second cold-forged blank 2 is greater than the length of the first cold-forged blank 1.

[0051] like Figure 4 As shown, step S4: Figure 3 The inner diameter and outer diameter of the front section of the second cold heading blank 2 are cold headed and reduced to form a third cold heading blank 3 having a third axial hole 31; the third axial hole 31 is formed by reducing the diameter of the second axial hole 21, so that the inner diameter of the third axial hole 31 is smaller than the inner diameter of the second axial hole 21, and the axial length of the third axial hole 31 is greater than the axial length of the second axial hole 21; the third cold heading blank 3 has a front section main shaft section 32, a rear section large diameter section 33 and a first transition section 34 connecting the main shaft section 32 and the large diameter section 33, the outer diameter of the large diameter section 33 is consistent with the outer diameter of the second cold heading blank 2, and the outer diameter of the main shaft section 32 is smaller than the outer diameter of the large diameter section 33.

[0052] On the basis of step S3, the inner diameter and outer diameter of the front section of the second cold heading blank 2 are cold headed and shrunk, and the rear section of the second cold heading blank 2 does not change, that is, the outer diameter of the large diameter section 33 is consistent with the outer diameter of the second cold heading blank 2, and the third axial hole 31 of the front section of the third cold heading blank 3 has a smaller inner diameter and an increased axial length than the second axial hole 21 in S3, and the main shaft section 32 has a smaller inner diameter and an increased axial length than the front section of the second cold heading blank 2 in step S3. The main shaft section 32 formed in this way is the main shaft section 32 of the final finished cold heading crankshaft blank 7.

[0053] like Figure 5 As shown, step S5: the large diameter section 33 (i.e. Figure 5 The right end part of the cold heading blank 3 is cold headed and reduced in diameter to form a fourth cold heading blank 4 having a main shaft section 32, an intermediate section 42 and a first secondary shaft section 41; the intermediate section 42 is located on the left side of the first secondary shaft section 41, a second transition section 43 is provided between the first secondary shaft section 41 and the intermediate section 42, and the first secondary shaft section 41 and the main shaft section 32 are respectively located on both sides of the intermediate section 42; the outer diameter of the intermediate section 42 is consistent with the outer diameter of the large diameter section 33 of the third cold heading blank 3, the outer diameter of the first secondary shaft section 41 is smaller than the outer diameter of the intermediate section 42, and the total axial length of the first secondary shaft section 41, the intermediate section 42 and the second transition section 43 is greater than the axial length of the large diameter section 33.

[0054] In step S5, the large diameter section 33 of the third cold heading blank 3 is cold headed to form a first sub-shaft section 41 and an intermediate section 42. The outer diameter of the first sub-shaft section 41 is smaller than the outer diameter of the intermediate section 42. The outer diameter of the intermediate section 42 is consistent with the outer diameter of the large diameter section 33 in S4. At the same time, a second transition section 43 for connecting the intermediate section 42 and the first sub-shaft section 41 is also cold forged.

[0055] like Figure 9-10 As shown, step S6: continue to cold-forge the fourth cold-forged blank 4 to form a cold-forged crankshaft blank 7 having a main shaft section 32 , an eccentric portion 71 and a second auxiliary shaft section 51 .

[0056] In step S6, since the second auxiliary shaft section 51 is formed by reducing the diameter of the first auxiliary shaft section 41, the axial length of the second auxiliary shaft section 51 is greater than the axial length of the first auxiliary shaft section 41, and the outer diameter of the second auxiliary shaft section 51 is smaller than the outer diameter of the first auxiliary shaft section 41; the eccentric portion 71 is formed by upsetting the first transition section 34, the middle section 42 and the second transition section 43, the axial length of the eccentric portion 71 is smaller than the axial length of the middle section 42, and the outer diameter of the eccentric portion 71 is greater than the outer diameter of the middle section 42. Example 2

[0057] The steps of this embodiment are substantially the same as those of embodiment 1, except that:

[0058] (i) In step S1, the steel material suitable for cold heading is selected as 20Cr.

[0059] (ii) In step S6, there is also a step S61.

[0060] like Figure 6 As shown, step S61: performing secondary cold heading and shrinking on the rear section of the fourth cold heading blank 4 (i.e., the first secondary shaft section 41) to form a fifth cold heading blank 5; the middle section 42 of the fifth cold heading blank 5 is consistent with the middle section 42 of the fourth cold heading blank 4 in axial length and outer diameter, the axial length of the second secondary shaft section 51 arranged at the end of the rear section of the fifth cold heading blank 5 is greater than the axial length of the first secondary shaft section 41, the outer diameter of the second secondary shaft section 51 is smaller than the outer diameter of the first secondary shaft section 41, the axial length of the third transition section 52 arranged between the middle section 42 of the fifth cold heading blank 5 and the main shaft section 32 is smaller than the axial length of the first transition section 34 of the fourth cold heading blank 4, and the axial length of the fourth transition section 53 arranged between the middle section 42 of the fifth cold heading blank 5 and the second secondary shaft section 51 is greater than the axial length of the second transition section 43.

[0061] In step S61, the first secondary shaft segment 41 is further cold-forged and elongated to form the second secondary shaft segment 51. At the same time, the second transition segment 43 is cold-forged and elongated to form the fourth transition segment 53, and the first transition segment 34 is cold-forged and compressed to form the third transition segment 52. The second secondary shaft segment 51 after cold-forging in step S6 is the second secondary shaft segment 51 of the final cold-forged crankshaft blank 7. Example 3

[0062] The steps of this embodiment are substantially the same as those of embodiment 1, except that:

[0063] (i) In step S1, the steel suitable for cold heading is 45 steel.

[0064] (ii) In step S6, there are also steps S62 and S63.

[0065] like Figure 7-8 As shown, step S62: cold heading the middle section 42, the first transition section 34, and the second transition section 43 of the fourth cold heading blank 4 to form a sixth cold heading blank 6; the sixth cold heading blank 6 has a burr eccentric portion 61 between the second secondary shaft section 51 and the main shaft section 32.

[0066] In step S62, the first transition section 34, the middle section 42, and the second transition section 43 are cold headed to form a sixth cold headed blank 6 with a burred eccentric portion 61. The main shaft section 32 and the third axial hole 31 of the sixth cold headed blank 6 are consistent with those of the third cold headed blank 3 and the fourth cold headed blank 4; the outer diameter of the second secondary shaft section 51 of the sixth cold headed blank 6 is smaller than the outer diameter of the first secondary shaft section 41; and both sides of the burred eccentric portion 61 are cold headed to form a plane.

[0067] Step S63 : removing the burrs 62 of the burr eccentric portion 61 on the sixth cold-headed blank 6 , thereby forming an eccentric portion 71 . Example 4

[0068] The steps of this embodiment are substantially the same as those of embodiment 2, except that:

[0069] (i) In step S1, the steel material suitable for cold heading is 40Cr.

[0070] (ii) After step S61, there are steps S62 and S63.

[0071] like Figure 7-8 As shown, step S62: cold heading the middle section 42, the third transition section 52, and the fourth transition section 53 of the fifth cold heading blank 5 to form a sixth cold heading blank 6; a burr eccentric portion 61 is provided between the second secondary shaft section 51 and the main shaft section 32 of the sixth cold heading blank 6.

[0072] In step S62, the third transition section 52, the fourth transition section 53, and the middle section 42 are cold headed to form a sixth cold headed blank 6 with a burred eccentric portion 61. The main shaft section 32 and the third axial hole 31 of the sixth cold headed blank 6 are consistent with those in the third cold headed blank 3, and the second secondary shaft section 51 of the sixth cold headed blank 6 is consistent with the second secondary shaft section 51 in the fifth cold headed blank 5. The difference is that the third transition section 52, the fourth transition section 53, and the middle section 42 are compressed and cold headed to form the burred eccentric portion 61; the two sides of the burred eccentric portion 61 are cold headed to form a plane.

[0073] Step S63: remove the burrs 62 of the burr eccentric portion 61 to form an eccentric portion 71; the outer diameter of the eccentric portion 71 is greater than the outer diameter of the middle section 42, and the axial length of the eccentric portion 71 is less than the sum of the axial lengths of the middle section 42, the third transition section 52, and the fourth transition section 53.

[0074] In step S63 , the burr 62 formed on the burr eccentric portion 61 after cold heading in step S62 is cut and removed, so as to form a cold-headed crankshaft blank 7 with an eccentric portion 71 .

[0075] The cold-headed crankshaft blank 7 manufactured in the above-mentioned Embodiments 1, 2, 3 and 4 is subsequently finely processed to form an air-conditioning crankshaft.

[0076] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A cold heading method for manufacturing an air conditioner crankshaft blank, characterized in that: The steps include: Step S1: Select steel suitable for cold heading processing, and cut out a cold heading steel cylinder (01) of appropriate length according to the specifications of the air-conditioning compressor crankshaft; Step S2: cold forging a positioning hole (11) on one end surface of a cold forged steel cylinder (01) to form a first cold forged blank (1); Step S3: performing cold heading along the axial direction of the positioning hole (11) of the first cold heading blank (1) to form a second cold heading blank (2) having a second axial hole (21); Step S4: cold heading and reducing the inner diameter and outer diameter of the second axial hole (21) of the second cold heading blank (2) to form a third cold heading blank (3) which is axially composed of a main shaft section (32) and a large diameter section (33), wherein the main shaft section (32) has a third axial hole (31) formed by reducing the diameter of the second axial hole (21); the main shaft section (32) formed is the main shaft section (32) of the cold heading crankshaft blank (7); the outer diameter of the large diameter section (33) is consistent with the outer diameter of the second cold heading blank (2), and the outer diameter of the main shaft section (32) is smaller than the outer diameter of the large diameter section (33); Step S5: cold heading and reducing the diameter of the large diameter section (33) at the other end of the third cold heading blank (3) to form a fourth cold heading blank (4) having a main shaft section (32), an intermediate section (42) and a first secondary shaft section (41) in the axial direction; Step S6: cold heading the middle section (42) and the first secondary shaft section (41) of the fourth cold heading blank (4) again to form the cold heading crankshaft blank (7) having a main shaft section (32), an eccentric section (71) and a second secondary shaft section (51).

2. A cold heading method for manufacturing an air conditioner crankshaft blank according to claim 1, characterized in that: In step S6, it also includes: Step S61: performing secondary cold heading and diameter reduction on the first secondary shaft section (41) of the fourth cold heading blank (4) to form a fifth cold heading blank (5) having a main shaft section (32), an intermediate section (42) and a second secondary shaft section (51).

3. A cold heading method for manufacturing an air conditioner crankshaft blank according to claim 1, characterized in that: In step S6, it also includes: Step S62: cold heading the middle section (42) and the first auxiliary shaft section (41) of the fourth cold heading blank (4) to form a sixth cold heading blank (6) having a main shaft section (32), a burr eccentric portion (61) and a second auxiliary shaft section (51); Step S63: removing the burrs (62) on the burr eccentric portion (61) of the sixth cold-headed blank (6) to form an eccentric portion (71).

4. A cold heading method for manufacturing an air conditioner crankshaft blank according to claim 2, characterized in that: In step S6, it also includes: Step S62: cold heading the middle section (42) of the fifth cold heading blank (5) to form a sixth cold heading blank (6) having a main shaft section (32), a burr eccentric portion (61) and a second secondary shaft section (51); Step S63: removing the burrs (62) on the burr eccentric portion (61) of the sixth cold-headed blank (6) to form an eccentric portion (71).

5. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S2, the outer diameter of the first cold heading blank (1) is consistent with the outer diameter of the cold heading steel cylinder (01), and the axis of the positioning hole (11) is colinear with the axis of the first cold heading blank (1).

6. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S3, the axial length of the second axial hole (21) is greater than the axial length of the positioning hole (11), the inner diameter of the second axial hole (21) is consistent with the inner diameter of the positioning hole (11), and the length of the second cold-headed blank (2) is greater than the length of the first cold-headed blank (1).

7. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S4, the inner diameter of the third axial hole (31) is smaller than the inner diameter of the second axial hole (21), and the axial length of the third axial hole (31) is greater than the axial length of the second axial hole (21); The third cold heading blank (3) comprises a front main shaft section (32), a rear large diameter section (33), and a first transition section (34) connecting the main shaft section (32) and the large diameter section (33).

8. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S5, the first secondary shaft section (41) and the main shaft section (32) are respectively located on both sides of the middle section (42), and a second transition section (43) is provided between the first secondary shaft section (41) and the middle section (42); The outer diameter of the middle section (42) is consistent with the outer diameter of the large diameter section (33); the outer diameter of the first secondary shaft section (41) is smaller than the outer diameter of the middle section (42); and the sum of the axial lengths of the first secondary shaft section (41), the middle section (42) and the second transition section (43) is greater than the axial length of the large diameter section (33).

9. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S6, the outer diameter of the second auxiliary shaft section (51) is smaller than the outer diameter of the first auxiliary shaft section (41), the outer diameter of the eccentric portion (71) is larger than the outer diameter of the middle section (42), and the axial length of the eccentric portion (71) is smaller than the sum of the axial lengths of the middle section (42), the first transition section (34), and the second transition section (43).

10. A cold heading method for manufacturing an air conditioner crankshaft blank according to claim 2, characterized in that: In step S61, the middle section (42) of the fifth cold heading blank (5) has the same axial length and outer diameter as the middle section (42) of the fourth cold heading blank (4); the axial length of the second secondary shaft section (51) arranged at the rear end of the fifth cold heading blank (5) is greater than the axial length of the first secondary shaft section (41); the outer diameter of the second secondary shaft section (51) is smaller than the outer diameter of the first secondary shaft section (41); the axial length of the third transition section (52) arranged between the middle section (42) of the fifth cold heading blank (5) and the main shaft section (32) is smaller than the axial length of the first transition section (34); the axial length of the fourth transition section (53) arranged between the middle section (42) of the fifth cold heading blank (5) and the second secondary shaft section (51) is greater than the axial length of the second transition section (43).

11. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 3 to 4, characterized in that: In step S62, the outer diameter of the burr eccentric portion (61) is greater than the outer diameter of the middle section (42), and the axial length of the burr eccentric portion (61) is less than the sum of the axial lengths of the middle section (42), the third transition section (52), and the fourth transition section (53); In step S63, the outer diameter of the eccentric portion (71) is consistent with the outer diameter of the burr eccentric portion (61).

12. A cold heading method for manufacturing an air conditioner crankshaft blank according to any one of claims 1 to 4, characterized in that: In step S1, the steel material of the cold-forged steel cylinder (01) is 40Cr, 20Cr, or 45 steel.

Images