Method and device for manufacturing axle housing blanks and axle housing blank, axle housing, axle and vehicle

Abstract

The application provides a method and device for manufacturing a bridge shell blank, the bridge shell blank, the bridge shell, the vehicle axle and the vehicle. The method for manufacturing the bridge shell blank comprises the following steps: selecting materials; installing an initial pipe blank on a pipe blank feeding mechanism of a bridge shell blank manufacturing device and installing a first core shaft on a core shaft feeding mechanism of the bridge shell blank manufacturing device; moving the initial pipe blank to an auxiliary die on a die frame through the pipe blank feeding mechanism and moving the first core shaft to the auxiliary die and into the initial pipe blank through the core shaft feeding mechanism; starting the auxiliary die to hit the initial pipe blank; continuing the movement of the initial pipe blank and the first core shaft; when the initial pipe blank and the first core shaft move, forging the initial pipe blank through the auxiliary die to obtain a special-shaped cross-section pipe blank, so that the outer diameter of the special-shaped cross-section pipe blank is increased and the wall thickness of the local position is thinned; after the initial pipe blank and the first core shaft reach a predetermined stroke, moving the special-shaped cross-section pipe blank and the first core shaft reversely; and performing radial forging and reducing processing on the pipe blank.

Description

Technical Field

[0001] This invention relates to the field of plastic forming technology for metal pipe fittings, and more particularly to a method and apparatus for manufacturing an axle housing blank, and the axle housing blank obtained therefrom, an axle housing made from the axle housing blank, an axle including the axle housing, and a vehicle including the axle. Background Technology

[0002] Automotive axle housings are complex tubular components, large in the middle and small at both ends, with irregular cross-sections in the transition sections and a wide range of dimensional variations. Casting and stamping / welding are currently the two main methods for manufacturing axle housings. Axle housings obtained by casting can meet the strength and rigidity requirements, but they suffer from drawbacks such as being heavy and energy-intensive. While axle housings obtained by stamping / welding reduce material consumption, they are prone to fatigue, short lifespan, and oil leakage due to the long weld seams, and the manufacturing time is also long.

[0003] Hot gas expansion forming is a new method for processing automotive axle housings. First, the diameter of both ends of a straight tube is reduced to form a stepped tube blank. Then, the stepped tube blank is placed in a forming mold, heated and kept at a certain temperature. After heating to a predetermined temperature, gas is injected into the stepped tube blank to obtain the automotive axle housing. However, the production efficiency of the stepped tube blank is low, and the uneven wall thickness distribution directly affects the forming quality of the automotive axle housing.

[0004] Existing methods for reducing tube diameter mainly include push-forming and spin-forming. Push-forming can easily lead to increased wall thickness, central instability, and difficulty in demolding. Spin-forming, on the other hand, relies on external spinning wheels for diameter reduction; the greater the change in the external dimensions of the tube, the more spinning cycles are required, resulting in longer processing time, higher production costs, and a tendency to produce uneven wall thickness distribution and surface roughness in stepped tube blanks. Directly using rotary forging for diameter reduction can also cause material accumulation in localized areas of the stepped tube blank, leading to uneven wall thickness distribution, which is also detrimental to subsequent processing of automotive axle housings. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for manufacturing bridge shell blanks. This method produces stepped tube blanks with high production efficiency, low cost, good forming quality, uniform wall thickness distribution, and a smooth surface.

[0006] To achieve the above objectives, the present invention provides a method for manufacturing a bridge housing blank, comprising the following steps: S1: Material selection, select a suitable initial tube blank according to the bridge shell structure to be achieved; S2: Install the initial tube blank on the tube blank feeding mechanism, and install the first mandrel on the mandrel feeding mechanism; S3: The initial tube blank is moved to the auxiliary mold on the mold frame by the tube blank feeding mechanism, and the first mandrel is moved to the auxiliary mold and enters the initial tube blank by the mandrel feeding mechanism; S4: The initial tube blank is heated by an induction coil; S5: After the initial tube blank is heated to the predetermined temperature, the auxiliary mold is activated to strike the initial tube blank; S6: Continue to move the initial tube blank, and at the same time continue to move the first mandrel. While the initial tube blank and the first mandrel are moving, the initial tube blank is forged by the auxiliary mold to change the shape of its cross section to obtain a tube blank with an irregular cross section, thereby increasing the outer diameter of the tube blank with an irregular cross section and reducing the wall thickness in a local position. S7: After the initial tube blank and the first mandrel reach the predetermined stroke, the irregular cross-section tube blank and the first mandrel are moved in opposite directions to move them away from the auxiliary mold. S8: Perform radial forging and diameter reduction processing on the irregular cross-section tube blank to obtain the bridge shell blank.

[0007] Further, step S8 includes: S8.1: After unloading the auxiliary mold and the first mandrel, install the diameter reduction mold on the mold frame and install the second mandrel on the mandrel feeding mechanism; S8.2: Move the irregular cross-section tube blank to the diameter reduction mold, and move the second mandrel to the diameter reduction mold and insert it into the diameter reduction mold; S8.3: The irregular cross-section tube blank is heated by an induction coil; S8.4: After the irregular cross-section tube blank is heated to the predetermined temperature, the irregular cross-section tube blank is rotated by the tube blank feeding mechanism, and at the same time the diameter reduction mold is activated to strike the irregular cross-section tube blank to obtain a first stepped tube blank with one end reduced in diameter. S8.5: Reverse the direction of the first stepped tube blank, clamp the small diameter end of the first stepped tube blank, reduce the diameter of the other end of the first stepped tube blank, and repeat steps S8.1-S8.4 to obtain a bridge shell blank with reduced diameter at both ends.

[0008] Furthermore, in step S8.1, the second mandrel is fixed relative to the press bed and is collinear with the central axis of the reduced diameter die when it is closed, and extends into the reduced diameter die.

[0009] Furthermore, in step S8.4, the irregular cross-section tube blank is kept rotating at a constant speed.

[0010] Furthermore, the first mandrel is an irregularly shaped mandrel.

[0011] Furthermore, the protrusions on the outer side of the first mandrel form a certain taper from high to low.

[0012] Furthermore, the installation direction of the auxiliary mold is consistent with the protrusion on the first mandrel.

[0013] Furthermore, the inner side of the auxiliary mold contacts the initial tube blank, and its radius is the same as the outer radius of the initial tube blank.

[0014] The present invention also provides an axle housing blank manufacturing apparatus, including a tube blank feeding mechanism, a mandrel feeding mechanism, a mold frame disposed between the tube blank feeding mechanism and the mandrel feeding mechanism, an auxiliary mold and a diameter reduction mold respectively mounted on the mold frame, and a first mandrel and a second mandrel respectively mounted on the mandrel feeding mechanism. The axle housing blank manufacturing apparatus is capable of performing the above-described axle housing blank manufacturing method.

[0015] Furthermore, the auxiliary mold includes two identical half-molds, each half-mold including an auxiliary outer mold, an auxiliary inner mold disposed inside the auxiliary outer mold, and an auxiliary connecting block disposed between the auxiliary outer mold and the auxiliary inner mold.

[0016] Furthermore, the diameter reduction die includes multiple dies arranged in a ring.

[0017] Furthermore, each segment of the diameter reduction mold includes a diameter reduction outer mold, a diameter reduction inner mold disposed inside the diameter reduction outer mold, and a diameter reduction connecting block disposed between the diameter reduction outer mold and the diameter reduction inner mold.

[0018] The present invention also provides a bridge housing blank, which is manufactured by the bridge housing blank manufacturing method described above.

[0019] The present invention also provides a bridge shell made from the above-mentioned bridge shell blank.

[0020] The present invention also provides an axle including the above-described axle housing.

[0021] The present invention further provides a vehicle including the above-described axle.

[0022] Compared with the prior art, the beneficial effects of the present invention are: 1. The bridge shell blank manufacturing method is a bridge shell blank manufacturing method with controllable wall thickness. The resulting stepped tube blank has high production efficiency, low cost, good forming quality, uniform distribution of variable wall thickness and smooth surface, which greatly simplifies the design and manufacturing cost and realizes the increase of outer diameter and local wall thickness reduction of irregular cross-section tube blank.

[0023] 2. This invention uses radial forging, which is suitable for narrow-necked workpieces with a large diameter-to-thickness ratio and long neck. It has very low requirements for the external dimensions, internal and external defects, internal structure and stress of the workpiece blank. Through forging, the internal structure of the workpiece will be strengthened and densified.

[0024] 3. The diameter reduction mold of the bridge housing blank manufacturing device adopts pure mechanical motion to achieve diameter reduction. It is simple in design, low in cost, short in production cycle and low in failure rate, which greatly improves development efficiency and effectively avoids the phenomenon of material accumulation at the transition position, ensuring a smooth transition of wall thickness.

[0025] 4. The bridge housing blank manufacturing device of the present invention has strong versatility and good flexibility for improvement.

[0026] 5. The axle obtained by this axle housing blank manufacturing method can achieve the purpose of lightweighting and material saving, thereby achieving the effect of saving energy consumption.

[0027] 6. Since the rear cover of the axle does not bear the load, the lower opening position needs to install components such as the differential. The wall thickness at these two positions can be reduced, while other positions bear more load, so the wall thickness gradually increases to ensure that the axle has sufficient strength. The wall thickness reduction position in the irregular cross-section tube blank obtained by the axle housing blank manufacturing method of the present invention facilitates the forming of the rear cover and can reduce material waste. Attached Figure Description

[0028] Figure 1 A schematic diagram of a bridge housing blank manufacturing apparatus according to an embodiment of the present invention is shown.

[0029] Figure 2 It shows Figure 1 A schematic diagram of the bridge housing blank manufacturing device from another direction.

[0030] Figure 3 It shows Figure 1 The diagram shows the structure of the auxiliary mold and the first mandrel (irregular mandrel) of the bridge housing blank manufacturing device.

[0031] Figure 4 It shows Figure 1 The side view of the bridge housing blank manufacturing apparatus shown, with the first mandrel passing through the auxiliary mold.

[0032] Figure 5 It shows the tube blank through Figure 1 The diagram shows the bridge housing blank manufacturing device after the cross-sectional shape has been changed.

[0033] Figure 6 It shows Figure 1 The diagram shows the structure of the diameter reduction mold and the second mandrel in the bridge housing blank manufacturing device.

[0034] Figure 7 It shows Figure 6 A cross-sectional view of the reduced-diameter mold when it is closed.

[0035] Figure 8 It shows the tube blank through Figure 1 The diagram shows the bridge housing blank manufacturing device during the diameter reduction process.

[0036] Figure 9A It shows one end of the tube blank through Figure 1 The diagram shown is a schematic of the bridge housing blank manufacturing device after diameter reduction.

[0037] Figure 9B It shows Figure 9A A schematic diagram of the wall thickness distribution at the transition position of the tube blank after diameter reduction.

[0038] Figure 9C The two ends of the tube blank are shown Figure 1 The diagram shown is a schematic of the bridge housing blank manufacturing device after diameter reduction.

[0039] Explanation of reference numerals in the attached drawings: 900-Bridge housing blank manufacturing device; 100-Blank blank feeding mechanism; 1-First mounting bracket; 11-First guide rail; 12-First rack; 200-Mandrel feeding mechanism; 2-Second mounting bracket; 21-Second guide rail; 22-Second rack; 3-First motor; 31-First slider; 32-First mounting seat; 4-Second motor; 41-Second slider; 42-Second mounting seat; 51-First gear; 52-Second gear; 53-Third gear; 54-First connecting shaft; 61-Fourth gear; 62-Fifth gear; 63-Sixth gear; 64-Seventh gear; 65-Second connecting shaft; 7-Third motor; 7 1-First fixed seat; 72-Material clamp; 81-Second fixed seat; 82-Chuck; 91-Eighth gear; 92-Ninth gear; 10-Initial tube blank; 101-Irregular cross-section tube blank; 102-First stepped tube blank; 103-Second stepped tube blank; 20-First mandrel; 30-Induction coil; 40-Auxiliary mold; 401-Auxiliary outer mold; 402-Auxiliary connecting block; 403-Auxiliary inner mold; 50-Mold frame; 60-Diameter reduction mold; 601-Diameter reduction outer mold; 602-Diameter reduction connecting block; 603-Diameter reduction inner mold; 70-Second mandrel; α-Taper; β-First guide angle; θ-Second guide angle; L-Length. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any component or element in this invention. They should not be construed as limiting the invention.

[0044] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0045] refer to Figure 1 and Figure 2 This invention provides a bridge housing blank manufacturing apparatus 900 with controllable wall thickness. The bridge housing blank manufacturing apparatus 900 includes a blank feeding mechanism 100, a mandrel feeding mechanism 200, a mold frame 50 disposed between the blank feeding mechanism 100 and the mandrel feeding mechanism 200, an auxiliary mold 40 and a diameter reduction mold 60 respectively mounted on the mold frame 50, and a first mandrel 20 and a second mandrel 70 respectively mounted on the mandrel feeding mechanism 200. A suitable initial blank 10 is selected according to the desired bridge housing structure. The initial blank 10 can be mounted on the blank feeding mechanism 100. The first mandrel 20 is used in conjunction with the auxiliary mold 40, and the second mandrel 70 is used in conjunction with the diameter reduction mold 60 to achieve different configurations of the initial blank 10. Specifically, the first mandrel 20 cooperates with the auxiliary mold 40 to increase the outer diameter of the initial tube blank 10 and reduce the wall thickness in local areas; the second mandrel 70 cooperates with the diameter reduction mold 60 to reduce the diameter of the tube blank with reduced wall thickness, thereby obtaining the required stepped tube blank, i.e., bridge shell blank.

[0046] In this embodiment, the billet feeding mechanism 100 includes a first mounting frame 1, a first guide rail 11 mounted on the first mounting frame 1, a first transmission component, and a first drive assembly. The first transmission component is disposed between two parallel first guide rails 11. In this embodiment, the first transmission component is configured as a first rack 12. The first drive assembly includes a first mounting base 32 slidably disposed on the first guide rail 11, and a first motor 3, a first driven assembly, a first fixed base 71, and a material clamp 72 mounted on the first mounting base 32. The bottom of the first mounting base 32 is provided with a plurality of first sliders 31, which engage with the first guide rail 11. In this embodiment, the shaft of the first motor 3 rotates vertically upward. In this embodiment, the first driven assembly is configured as a first gear set. The first gear set meshes with the first rack 12. The first gear set includes a first gear 51, a second gear 52, and a third gear 53. The first gear 51 is mounted on the shaft of the first motor 3. The second gear 52 engages with the first gear 51. The second gear 52 is connected to the third gear 53 via the first connecting shaft 54. The third gear 53 meshes with the first rack 12. A clamp 72 is disposed on the side of the first fixed seat 71 facing the mold frame 50. The initial tube blank 10 is clamped in the clamp 72. Preferably, the clamp 72 is a barrel-shaped clamp. The first motor 3 drives the first gear set to rotate, causing the third gear 53 to move relative to the first rack 12, thereby driving the first mounting seat 32 to move relative to the first mounting frame 1, thus realizing the reciprocating feed of the initial tube blank 10 for subsequent processing.

[0047] The spindle feed mechanism 200 includes a second mounting bracket 2, a second guide rail 21 mounted on the second mounting bracket 2, a second transmission component, and a second drive assembly. Optionally, the first mounting bracket 1 and the second mounting bracket 2 are an integral mounting bracket or a punch press bed. In this embodiment, the second transmission component is configured as a second rack 22. The second rack 22 is disposed between two parallel second guide rails 21. The second drive assembly includes a second mounting seat 42 slidably disposed on the second guide rail 21, and a second motor 4, a second driven group, a second fixed seat 81, and a chuck 82 mounted on the second mounting seat 42. The bottom of the second mounting seat 42 is provided with a plurality of second sliders 41, which engage with the second guide rails 21. In this embodiment, the shaft of the second motor 4 is horizontally arranged. Preferably, the second driven group is configured as a second gear set. The second gear set meshes with the second rack 22. The second gear set includes a fourth gear 61, a fifth gear 62, a sixth gear 63, and a seventh gear 64. The fifth gear 62 and the sixth gear 63 are connected by a second connecting shaft 65. The specific arrangement of the fourth gear 61, fifth gear 62, sixth gear 63, and seventh gear 64 of the second gear set can be referred to the description of the first gear set above, and will not be repeated here. A chuck 82 is disposed on the side of the second fixed seat 81 facing the mold frame 50, and the first mandrel 20 is clamped on the chuck 82. Preferably, the chuck 82 is a three-jaw chuck. More preferably, the first mandrel 20 is an irregularly shaped mandrel. A protrusion is provided on the outer side of the first mandrel 20. The second motor 4 drives the second gear set to rotate, causing the seventh gear 64 to move relative to the second rack 22, thereby driving the second mounting seat 42 to move relative to the second mounting bracket 2, thus realizing the reciprocating feed of the first mandrel 20 for processing to reduce the wall thickness at corresponding positions on the initial tube blank 10.

[0048] An auxiliary mold 40, used in conjunction with the first mandrel 20, is mounted on the mold frame 50 to reduce the wall thickness of the initial tube blank 10 and to round it. An induction coil 30 for heating the tube blank is provided on the side of the mold frame 50 facing the tube blank feeding mechanism 100. (See also...) Figures 2 to 5The auxiliary mold 40 includes two identical half-molds. Each half-mold includes an auxiliary outer mold 401, an auxiliary inner mold 403 disposed inside the auxiliary outer mold 401, and an auxiliary connecting block 402 disposed between the auxiliary outer mold 401 and the auxiliary inner mold 403. In this embodiment, the inner side of the auxiliary inner mold 403 contacts the initial tube blank 10, and its radius is the same as the outer radius of the initial tube blank 10, in order to maintain the external shape of the initial tube blank 10. The mounting direction of the auxiliary mold 40 is consistent with the protrusion on the first mandrel 20, that is, the auxiliary mold 40 is mounted on the mold frame 50 facing the protrusion on the first mandrel 20. In this way, when the auxiliary mold 40 reciprocates, it can reduce the wall thickness of the initial tube blank 10 at this point by cooperating with the protrusion on the first mandrel 20. In order to facilitate the entry and exit of the first mandrel 20 into the initial tube blank 10, the protrusion on the first mandrel 20 forms a certain taper α from high to low. In this embodiment, the protrusion at the end of the first spindle 20 (already clamped on the chuck 82) facing away from the chuck 82 is low.

[0049] Specifically, the initial tube blank 10 is clamped on the clamp 72 of the first drive assembly, and the first mandrel 20 is clamped on the chuck 82. The first motor 3, mounted on the first mounting base 32, rotates forward, driving each gear of the first gear set to rotate, causing the third gear 53 of the first gear set to rotate relative to the first rack 12. This causes the first fixed seat 71, mounted on the first mounting base 32, to move toward the auxiliary mold 40 on the mold frame 50. As a result, the clamp 72 clamps the initial tube blank 10 and moves it quickly to the auxiliary mold 40. The second motor 4, mounted on the second mounting base 42, rotates forward, driving each gear of the second gear set to rotate, causing the seventh gear 64 of the second gear set to rotate relative to the second rack 22. This causes the second fixed seat 81, mounted on the second mounting base 42, to move toward the auxiliary mold 40. As a result, the chuck 82 clamps the first mandrel 20 and moves it quickly to the auxiliary mold 40 and into the initial tube blank 10. The high-frequency induction coil 30 heats the initial tube blank 10. After the initial tube blank 10 is heated to the predetermined temperature, the auxiliary mold 40 is activated, causing it to reciprocate and strike the initial tube blank 10. The first motor 3 rotates forward, and after being reduced in speed by the first gear 51 and the second gear 52, the third gear 53 meshes with the first rack 12. Through the cooperation of the first guide rail 11 and the first slider 31, the initial tube blank 10 moves to the right along the centerline of the auxiliary mold 40. The second motor 4 rotates forward, and after being reduced in speed by the fourth gear 61, the fifth gear 62, the sixth gear 63, and the seventh gear 64, the seventh gear 64 meshes with the second rack 22. Through the cooperation of the second guide rail 21 and the second slider 41, the first mandrel 20 moves to the left along the centerline of the auxiliary mold 40. Simultaneously with the movement of the initial tube blank 10 and the first mandrel 20, the auxiliary mold 40 reciprocates, forging the initial tube blank 10 and changing its cross-sectional shape. After the initial tube blank 10 and the first mandrel 20 reach the predetermined stroke, the first motor 3 reverses, causing the gears of the first gear set to also reverse, and the third gear 53 to reverse relative to the first rack 12, causing the material clamp 72 to move in the opposite direction. This causes the irregularly shaped cross-section tube blank 101, whose thickness has been changed at the corresponding position, to move to the left along the center line of the auxiliary mold 40. The second motor 4 reverses, causing the gears of the second gear set to also reverse, and the seventh gear 64 to reverse relative to the second rack 22, causing the chuck 82 to move in the opposite direction. This causes the first mandrel 20 to move to the right along the center line of the auxiliary mold 40. In the above operation, after the first impact, the initial tube blank 10 is out of round. The cross-section of the tube blank after rounding is as follows: Figure 5 As shown, the outer diameter of the irregular cross-section tube blank 101 increases at this time. Through the first impact, the outer diameter of the irregular cross-section tube blank is increased and the wall thickness is reduced in local areas.

[0050] After the auxiliary mold 40 and the first mandrel 20 have cooled and been unloaded, the diameter reduction mold 60 is installed on the mold frame 50, and the second mandrel 70 is installed on the mandrel feed mechanism 200 for subsequent diameter reduction processing of the irregular cross-section tube blank 101. Preferably, the second mandrel 70 is clamped on the chuck 82 of the mandrel feed mechanism 200.

[0051] Also refer to Figures 6 to 9C The diameter reduction mold 60 includes multiple molds arranged in a ring. In this embodiment, the diameter reduction mold 60 is a multi-lobed mold with a central hole, having at least two lobes, preferably a four-lobed diameter reduction mold. Preferably, each lobe mold includes a diameter reduction outer mold 601, a diameter reduction inner mold 603 disposed inside the diameter reduction outer mold 601, and a diameter reduction connecting block 602 disposed between the diameter reduction outer mold 601 and the diameter reduction inner mold 603. The irregular cross-section tube blank 101 enters the diameter reduction mold 60. When the diameter reduction mold 60 is closed, the internal cross-sectional shape is consistent with the diameter change taper of the irregular cross-section tube blank 101 after diameter reduction. The diameter reduction mold 60 cooperates with the second mandrel 70 to control the wall thickness of the straight section of the irregular cross-section tube blank 101 after diameter reduction. The closed diameter reduction die 60 has a second guide angle θ at its entrance and a first guide angle β in its middle, where the first guide angle β is smaller than the second guide angle θ to ensure a smooth shape transition for the first stepped tube blank 102. An L-length guide section is provided at the exit to control the diameter of the smaller diameter end of the first stepped tube blank 102 after diameter reduction. Preferably, during the diameter reduction operation, one of the four segments of the diameter reduction die 60 is fixed, while the other three segments reciprocate linearly, striking the irregularly shaped cross-section tube blank 101 to form the first stepped tube blank 102. The second mandrel 70, mounted on the mandrel feed mechanism 200, is fixed relative to the press bed and collinear with the central axis of the diameter reduction die 60 when closed, extending into the diameter reduction die 60. Both mandrels control the wall thickness of the straight section of the tube blank after diameter reduction. Preferably, the working section diameter of the second mandrel 70 is larger than the diameters of the other parts to reduce the resistance of the straight section after diameter reduction.

[0052] In this embodiment, the irregular cross-section tube blank 101 is kept rotating during diameter reduction by a third drive assembly mounted on the first fixed base 71. The third drive assembly includes a third motor 7 and a third driven group. Preferably, the third motor 7 drives the material clamp 72 to rotate via the third driven group, thereby causing the irregular cross-section tube blank 101 to rotate. The shaft of the third motor 7 is positioned away from the material clamp 72. In this embodiment, the third driven group is configured as a third gear set. The third gear set includes an eighth gear 91 mounted on the shaft of the third motor 7 and a ninth gear 92 meshing with the eighth gear 91. The ninth gear 92 is connected to the material clamp 72 via a corresponding connecting shaft, so that the rotation of the ninth gear 92 drives the material clamp 72 to rotate. In this embodiment, the irregular cross-section tube blank 101 maintains a uniform rotation speed.

[0053] The irregular cross-section tube blank 101 is clamped on the material clamp 72 of the first drive assembly, and the second mandrel 70 is clamped on the chuck 82 of the second drive assembly. The first motor 3, mounted on the first mounting base 32, rotates forward, driving each gear of the first gear set to rotate, causing the third gear 53 of the first gear set to rotate relative to the first rack 12. This causes the first fixed seat 71, mounted on the first mounting base 32, to move toward the diameter reduction mold 60 on the mold frame 50. As a result, the material clamp 72 clamps the irregular cross-section tube blank 101 and moves it quickly to the diameter reduction mold 60. The second motor 4, mounted on the second mounting base 42, rotates forward, driving each gear of the second gear set to rotate, causing the seventh gear 64 of the second gear set to rotate relative to the second rack 22. This causes the second fixed seat 81, mounted on the second mounting base 42, to move toward the diameter reduction mold 60. As a result, the chuck 82 clamps the second mandrel 70 and moves it quickly to the diameter reduction mold 60. At this time, the position of the second mandrel 70 is fixed and coaxial with the center line of the diameter reduction mold 60. The third motor 7 of the third drive assembly starts, driving the gears of the third gear set to rotate. This causes the ninth gear 92 to drive the material clamp 72 to rotate, thereby causing the irregular cross-section tube blank 101 to rotate. Preferably, the irregular cross-section tube blank 101 is kept rotating at a uniform speed. The high-frequency induction coil 30 heats the irregular cross-section tube blank 101. After the irregular cross-section tube blank 101 is heated to a predetermined temperature, the diameter reduction mold 60 is activated, causing it to reciprocate and strike the irregular cross-section tube blank 101. This results in a first stepped tube blank 102 with one end reduced in diameter. Then, the first motor 3 reverses, causing the gears of the first gear set to also reverse. The third gear 53 reverses relative to the first rack 12, causing the material clamp 72 to move in the opposite direction, thereby causing the first stepped tube blank 102 to move to the left along the center line of the diameter reduction mold 60. Then, the orientation of the first-step tube blank 102 is reversed, and the smaller diameter end of the first-step tube blank 102 is clamped. The other end of the first-step tube blank 102 is then reduced in diameter. This operation is repeated to obtain the second-step tube blank 103, i.e., the bridge shell blank, with both ends reduced in diameter. The wall thickness distribution at the transition position of the first-step tube blank 102 after the reduction in diameter of the irregular cross-section tube blank 101 is as follows: Figure 9B As shown, this effectively avoids material accumulation at transition points and ensures a smooth transition in wall thickness.

[0054] It is conceivable that the number of gears in the above embodiments can be adjusted as needed, and that the gears can be mounted on corresponding mounting bases or fixed bases via corresponding shafts and support frames. It is also conceivable that the gear and rack design can be replaced by other available structures, such as belts and pulleys, lead screw structures, sprocket chains, etc.

[0055] This invention also provides a method for manufacturing a bridge housing blank. This method has high production efficiency and low cost, produces a stepped tube blank with good forming quality, uniform wall thickness distribution, and a smooth surface. The method for manufacturing the bridge housing blank includes the following steps: S1: Material selection, select a suitable initial tube blank according to the bridge shell structure to be achieved; S2: Install the initial tube blank on the tube blank feeding mechanism, and install the first mandrel on the mandrel feeding mechanism; S3: The initial tube blank is moved to the auxiliary mold on the mold frame by the tube blank feeding mechanism, and the first mandrel is moved to the auxiliary mold and enters the initial tube blank by the mandrel feeding mechanism; S4: Heating the initial tube blank using an induction coil; S5: After the initial tube blank is heated to the predetermined temperature, the auxiliary mold is activated to strike the initial tube blank; S6: Continue moving the initial tube blank and the first mandrel. While the initial tube blank and the first mandrel are moving, the initial tube blank is forged by the auxiliary mold to change the shape of its cross section and obtain a tube blank with an irregular cross section, thereby increasing the outer diameter of the tube blank with an irregular cross section and reducing the wall thickness in a local position. S7: After the initial tube blank and the first mandrel reach the predetermined stroke, the irregular cross-section tube blank is moved in the opposite direction, and the first mandrel is moved in the opposite direction at the same time. S8: Perform radial forging and diameter reduction processing on the irregular cross-section tube blank to obtain the bridge shell blank.

[0056] In step S1, material selection includes determining the length, diameter, and wall thickness of the initial tube blank by, for example, by the shape of the axle.

[0057] In step S2, the initial tube blank is clamped in the material clamp of the tube blank feeding mechanism, and the first mandrel is clamped in the chuck of the mandrel feeding mechanism.

[0058] In step S3, after the material clamp holds the initial tube blank, it moves quickly to the auxiliary mold under the action of the first drive component. The chuck holds the first mandrel and moves quickly to the auxiliary mold under the action of the second drive component and enters the initial tube blank.

[0059] In step S4, preferably, the temperature of the initial tube blank is detected using a sensor (e.g., a temperature sensor) until a preset temperature range is reached.

[0060] Step S8 of the bridge housing blank manufacturing method includes: S8.1: After unloading the auxiliary mold and the first mandrel, install the diameter reduction mold on the mold frame and install the second mandrel on the mandrel feeding mechanism; S8.2: The tube blank with irregular cross section is moved to the diameter reduction mold by the tube blank feeding mechanism, and the second mandrel is moved to the diameter reduction mold and inserted into the diameter reduction mold by the mandrel feeding mechanism; S8.3: Heating irregularly shaped tube blanks using induction coils; S8.4: After the irregular cross-section tube blank is heated to the predetermined temperature, the irregular cross-section tube blank is rotated by the tube blank feeding mechanism, and at the same time the diameter reduction die is activated to strike the irregular cross-section tube blank to obtain a first stepped tube blank with one end reduced in diameter. S8.5: Reverse the direction of the first stepped tube blank, clamp the small diameter end of the first stepped tube blank, reduce the diameter of the other end of the first stepped tube blank, and repeat the above steps S8.1-S8.4 to obtain the second stepped tube blank with reduced diameter at both ends, i.e., the bridge shell blank.

[0061] In step S8.1, after the auxiliary mold and the first mandrel have cooled down, the auxiliary mold and the first mandrel are unloaded, and the second mandrel is clamped in the chuck of the mandrel feeding mechanism.

[0062] In step S8.2, the second mandrel is fixed relative to the press bed and is collinear with the central axis when the reducing die is closed, and extends into the reducing die.

[0063] In step S8.3, preferably, the temperature of the irregular cross-section tube blank is detected by a sensor (e.g., a temperature sensor) until a preset temperature range is reached.

[0064] In step S8.4, preferably, the irregular cross-section tube blank is kept rotating at a constant speed.

[0065] The stepped tube blank obtained by this invention has high production efficiency, low cost, and good forming quality. It can effectively control the wall thickness of local positions of the tube blank during the diameter reduction process, making the wall thickness distribution of the stepped tube blank more uniform.

[0066] The axle housing blank manufacturing method and / or axle housing blank manufacturing apparatus of the preferred embodiments of the present invention are applicable to all axles and their axle housings, as well as vehicles including said axles.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a bridge shell blank, characterized in that, Includes the following steps: S1: Material selection, select a suitable initial tube blank according to the bridge shell structure to be achieved; S2: Install the initial tube blank on the tube blank feeding mechanism, and install the first mandrel on the mandrel feeding mechanism; S3: The initial tube blank is moved to the auxiliary mold on the mold frame by the tube blank feeding mechanism, and the first mandrel is moved to the auxiliary mold and enters the initial tube blank by the mandrel feeding mechanism; S4: The initial tube blank is heated by an induction coil; S5: After the initial tube blank is heated to the predetermined temperature, the auxiliary mold is activated to strike the initial tube blank; S6: Continue to move the initial tube blank, and at the same time continue to move the first mandrel. While the initial tube blank and the first mandrel are moving, the initial tube blank is forged by the auxiliary mold to change the shape of its cross section to obtain a tube blank with an irregular cross section, thereby increasing the outer diameter of the tube blank with an irregular cross section and reducing the wall thickness in a local position. S7: After the initial tube blank and the first mandrel reach the predetermined stroke, the irregular cross-section tube blank and the first mandrel are moved in opposite directions to move them away from the auxiliary mold. S8: Perform radial forging and diameter reduction processing on the irregular cross-section tube blank to obtain a bridge shell blank; The first mandrel is an irregularly shaped mandrel; or the protrusions on the outer side of the first mandrel form a certain taper from high to low, and the installation direction of the auxiliary mold is consistent with the protrusions on the first mandrel; or the inner side of the auxiliary mold contacts the initial tube blank, and its radius is the same as the outer radius of the initial tube blank.

2. The method for manufacturing bridge housing blanks according to claim 1, characterized in that, Step S8 includes: S8.1: After unloading the auxiliary mold and the first mandrel, install the diameter reduction mold on the mold frame and install the second mandrel on the mandrel feeding mechanism; S8.2: Move the irregular cross-section tube blank to the diameter reduction mold, and move the second mandrel to the diameter reduction mold and insert it into the diameter reduction mold; S8.3: The irregular cross-section tube blank is heated by an induction coil; S8.4: After the irregular cross-section tube blank is heated to the predetermined temperature, the irregular cross-section tube blank is rotated by the tube blank feeding mechanism, and at the same time the diameter reduction mold is activated to strike the irregular cross-section tube blank to obtain a first stepped tube blank with one end reduced in diameter. S8.5: Reverse the direction of the first stepped tube blank, clamp the small diameter end of the first stepped tube blank, reduce the diameter of the other end of the first stepped tube blank, and repeat steps S8.1-S8.4 to obtain a bridge shell blank with reduced diameter at both ends.

3. The method for manufacturing bridge housing blanks according to claim 2, characterized in that, In step S8.1, the second mandrel is fixed relative to the press bed and is collinear with the central axis of the diameter reduction die when it is closed, and extends into the diameter reduction die; in step S8.4, the irregular cross-section tube blank maintains uniform rotation.

4. A bridge housing blank manufacturing apparatus, comprising a blank feeding mechanism, a mandrel feeding mechanism, a mold frame disposed between the blank feeding mechanism and the mandrel feeding mechanism, an auxiliary mold and a diameter reduction mold respectively mounted on the mold frame, and a first mandrel and a second mandrel respectively mounted on the mandrel feeding mechanism, wherein the mold frame is provided with an induction coil for heating the blank on the side facing the blank feeding mechanism, characterized in that, The bridge housing blank manufacturing apparatus performs the bridge housing blank manufacturing method according to any one of claims 1 to 3.

5. The bridge housing blank manufacturing apparatus according to claim 4, characterized in that, The auxiliary mold includes two identical half molds, each half mold including an auxiliary outer mold, an auxiliary inner mold disposed inside the auxiliary outer mold, and an auxiliary connecting block disposed between the auxiliary outer mold and the auxiliary inner mold; The diameter reduction mold includes multiple molds arranged in a ring. Each segment of the diameter reduction mold includes an outer diameter reduction mold, an inner diameter reduction mold disposed inside the outer diameter reduction mold, and a diameter reduction connecting block disposed between the outer diameter reduction mold and the inner diameter reduction mold.

6. A bridge shell blank, characterized in that, Manufactured by the bridge housing blank manufacturing method according to any one of claims 1 to 3.

7. A bridge housing, characterized in that, It is made from the bridge housing blank as described in claim 6.

8. An axle, comprising an axle housing, characterized in that, The bridge housing is the bridge housing as described in claim 7.

9. A vehicle, including an axle, characterized in that, The axle is the axle according to claim 8.

Images