Cross wedge rolling mechanism, device and method for rolling laminated shaft

Abstract

A cross wedge rolling mechanism comprises a drive mechanism and two paralleled and opposed cross rolling moulds; the drive mechanism is in transmission connection with at least one cross rolling mould and drives the cross rolling mould to move; a contact surface in contact with the laminated shaft is disposed on the cross rolling moulds, wherein a pre-squeezing stripe protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould; a shaping wedge protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould; an included angle of an extending direction of the pre-squeezing stripe and a moving direction of the cross rolling mould is limited; the pre-squeezing stripe is disposed in front of the shaping wedge such that the laminated shaft sequentially runs over the pre-squeezing stripe and the shaping wedge during moulding.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of cross wedge rolling technologies and in particular to a cross wedge rolling mechanism, device and method for rolling a laminated shaft.BACKGROUND

[0002] The heterogeneous metal laminated shaft can combine the advantages of different materials to reach the effect of “1+1>2”. For example, the 42 CrMo / 45 steel laminated shaft has a cost half that of the axle steel shaft. In the prior arts, the heterogeneous metal laminated shaft is mainly prepared in the following manners: firstly, the explosion cladding bars are used and subsequently shaped by a process such as cross wedge rolling or forging or the like. But this method has the disadvantages of tedious process, lengthy flow, high costs of explosion welding and low efficiency, failing to satisfy the requirements of large-batch production of the axles; secondly, the inner and outer surfaces of two bars are polished and their ends are welded and then rolled into shape by cross wedge rolling process. The cross wedge rolling device is a common one in cross wedge rolling process. However, For the laminated shaft prepared by the device and method, a combination interface of its inner shaft and outer shaft is presented as straight with limited combination strength and therefore may tend to crack and peel off inside and outside under a load such as bending, twisting, shearing and pressing and the like in a subsequent service process, failing to satisfy the requirements of the axial shear resistance and the circumferential twist resistance of the laminated shaft.SUMMARY

[0003] In order to overcome the shortcomings of the prior arts, the present disclosure provides a cross wedge rolling mechanism for rolling a laminated shaft so as to roll a laminated shaft with wavy combination surface, which ensures low processing costs and enables the formed laminated shaft to have the characteristics of axial shear resistance and circumferential twist resistance.

[0004] In order to achieve the above objects, the present disclosure provides the following technical solution.

[0005] There is provided a cross wedge rolling mechanism for rolling a laminated shaft, which comprises a drive mechanism and two paralleled and opposed cross rolling moulds. The drive mechanism is in transmission connection with at least one cross rolling mould and drives the cross rolling mould to move. A contact surface in contact with the laminated shaft is disposed on the cross rolling moulds and a pre-squeezing stripe protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould. A shaping wedge protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould. An included angle α of an extending direction of the pre-squeezing stripe and a moving direction of the cross rolling mould is less than 45°. The pre-squeezing stripe is disposed in front of the shaping wedge such that the laminated shaft can sequentially run over the pre-squeezing stripe and the shaping wedge during moulding.

[0006] In the above technical solution, the laminated shaft is composed of an inner shaft and an outer shaft sleeved outside the inner shaft; the inner shaft and the outer shaft are fixed by close fit and end welding. The pre-squeezing stripe and the shaping wedge can be disposed as different shapes and sizes based on requirements of actual products. The working principle of the solution is as below: the laminated shaft is placed between the two cross rolling moulds and the two cross rolling moulds are located at opposed sides of the laminated shaft and then driven by the drive mechanism to move; during the movement process of the cross rolling moulds, the laminated shaft rolls relative to the two cross rolling moulds. A cylindrical surface of the laminated shaft firstly rolls over the pre-squeezing stripe and is squeezed by the pre-squeezing stripe to leave an indentation on an outer surface of the outer shaft while transferring the indentation to the inner shaft, and next, the laminated shaft continues rolling over the shaping wedge and leaves the indentation on the outer surface of the outer shaft rolled flat under the squeezing effect of the shaping wedge; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge to a combination interface of the inner shaft and the outer shaft; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the outer shaft and the inner shaft has wavy characteristics. The above technical solution can not only realize rolling on the laminated shaft under high temperature but also enable the combination interface of the outer and inner shafts of the rolled laminated shaft to have wavy mechanical engagement, making the formed laminated shaft have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing costs will not be increased.

[0007] Preferably, the drive mechanism is a linear drive mechanism, and the cross rolling moulds are plate-type moulds. The linear drive mechanism is connected with at least one plate-type mould such that the two plate-type moulds can translate toward each other. The contact surface is used to abut against a support surface of the laminated shaft.

[0008] The working principle of the above technical solution is as follows: the laminated shaft is placed between the two plate-type moulds and clamped on both sides by the two plate-type moulds, and then the linear drive mechanism drives the two plate-type moulds to translate toward each other; in the translation process, the laminated shaft rolls relative to the two plate-type moulds. The cylindrical surface of the laminated shaft firstly rolls over the pre-squeezing stripe and is squeezed by the pre-squeezing stripe to leave an indentation on an outer surface of the outer shaft while transferring the indentation to the inner shaft, and next, the laminated shaft continues rolling over the shaping wedge and leaves the indentation on the outer surface of the outer shaft rolled flat under the squeezing effect of the shaping wedge; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge to a combination interface of the inner shaft and the outer shaft; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the outer shaft and the inner shaft has wavy characteristics.

[0009] Preferably, the drive mechanism is a rotation drive mechanism, and the cross rolling moulds are cross rolling rollers which move in opposite directions. The rotation drive mechanism is in transmission connection with at least one cross rolling roller and drives the cross rolling roller to rotate. The contact surface is a peripheral rolling arc surface of the cross rolling rollers, and the pre-squeezing stripe extends along a peripheral direction of the rolling arc surface.

[0010] The working principle of the above technical solution is as follows: the laminated shaft is placed between the two cross rolling rollers and the rotation drive mechanism drives the cross rolling rollers to rotate; when the cross rolling rollers rotate, the cylindrical surface of the laminated shaft firstly rolls over the pre-squeezing stripe and is squeezed by the pre-squeezing stripe to leave an indentation on an outer surface of the outer shaft while transferring the indentation to the inner shaft, and next, the laminated shaft continues rolling over the shaping wedge and leaves the indentation on the outer surface of the outer shaft rolled flat under the squeezing effect of the shaping wedge; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge to a combination interface of the inner shaft and the outer shaft; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the outer shaft and the inner shaft has wave characteristics. Finally, the formed laminated shaft is taken down from a positioning assembly and a new unformed laminated shaft is placed into the positioning assembly again to continue the processing of the next part. In the above technical solution, the cross rolling rollers can provide reliable support for the rolling arc surfaces, ensuring the structural strength and stability of the rolling arc surfaces and hence ensuring the quality stability of the formed products.

[0011] Preferably, at least one of the cross rolling rollers comprises a roller body and a cross rolling arc plate detachably mounted on a cylindrical surface of the roller body; the cross rolling arc plate partially wraps the roller body along a circumferential direction of the cross rolling roller and protrudes out of the cylindrical surface of the roller body; the rolling arc surface is disposed on the cross rolling arc plate.

[0012] In the above technical solution, the detachable mounting of the cross rolling arc plate makes its processing more flexible and thus the cross rolling arc plate can be processed separately, increasing the processing efficiency and accuracy. In this way, the processing difficulty is reduced and the entire processing cost is lowered. Further, a cross rolling arc plate with corresponding model can be used based on a different size of the laminated shaft, increasing the universality and adaptability of the cross rolling roller and satisfying the diversified production requirements.

[0013] Preferably, the radiuses of the two cross rolling rollers are R1 and R2 respectively, a distance between the two axes of the two cross rolling rollers is L, and an outer diameter of the laminated shaft is D1, where R1+R2+D1≤L≤H0+R1+R2+D1. When only one cross rolling roller comprises the cross rolling arc plate, the H0 is a height that the rolling arc surface in the cross rolling arc plate protrudes out of the cylindrical surface of the roller body; when each of two cross rolling rollers comprises the cross rolling arc plate, the H0 is a sum of the heights that the two rolling arc surfaces protrude out of the cylindrical surfaces of the corresponding roller bodies.

[0014] In the above technical solution, the detachable mounting of the cross rolling arc plate makes its processing more flexible and thus the cross rolling arc plate can be processed separately, increasing the processing efficiency and accuracy. In this way, the processing difficulty is reduced and the entire processing cost is lowered. Further, a cross rolling arc plate with corresponding model can be used based on a different size of the laminated shaft, increasing the universality and adaptability of the cross rolling roller and satisfying the diversified production requirements. In the above technical solution, with R1+R2+D1≤L, when the rolling arc surface is not aligned with the laminated shaft, the laminated shaft is not in contact with the cylindrical surface of the cross rolling roller, helping put in or take out the laminated shaft. With L≤H0+R1+R2+D1, when the cross rolling roller rotates to facing toward the laminated shaft, the rolling arc surface can closely press the laminated shaft such that the rolling arc surface can effectively bring the laminated shaft to rotate and process it into a desired shape while limiting and ensuring the outer diameter of the processed laminated shaft. A transitional surface can enable the cylindrical surface to correspondingly transition from the cylindrical surface of the roller body to and abut against the rolling arc surface smoothly.

[0015] Preferably, distances of the two rolling arc surfaces from the axes of the corresponding cross rolling rollers are L1 and L2 respectively, and the distance between the two axes of the two cross rolling rollers is L, and the outer diameter of the laminated shaft is D1, where L1+L2+D1≤L;

[0016] when the pre-squeezing stripe is disposed on the rolling arc surface of only one cross rolling roller, a height that the pre-squeezing stripe protrudes out of the corresponding rolling arc surface is H1, where H1+L1+L2+D1≥L;

[0017] when the pre-squeezing stripe is disposed on the rolling arc surface of each of the two cross rolling rollers, the heights that the two pre-squeezing stripes protrude out of the corresponding rolling arc surfaces are H1 and H2, where H1+H2+L1+L2+D1≥L;

[0018] when the shaping wedge is disposed on the rolling arc surface of only one cross rolling roller, the height that the shaping wedge protrudes out of the corresponding rolling arc surface is H3, where H3+L1+L2+D1≥L;

[0019] when the shaping wedge is disposed on the rolling arc surface of each of the two cross rolling rollers, the heights that the two shaping wedges protrude out of the corresponding rolling arc surfaces are H3 and H4, where H3+H4+L1+L2+D1≥L.

[0020] In the above technical solution, with L1+L2+D1≤L, when the pre-squeezing stripe or the shaping wedge is not aligned with the laminated shaft, the laminated shaft is not in contact with the cylindrical surface of the cross rolling roller and the rolling arc surface, helping put in and take out the laminated shaft. When the pre-squeezing stripe or the shaping wedge is aligned with the laminated shaft, the pre-squeezing stripe or the shaping wedge can be tightly pressed onto the laminated shaft such that the pre-squeezing stripe or the shaping wedge can effectively bring the laminated shaft to rotate and process it into a desired shape.

[0021] Preferably, the pre-squeezing stripe extends helically along a peripheral direction of the cross rolling roller, and a helical angle of the pre-squeezing stripe is β, where β=90°−α and 80°β90°.

[0022] In the above technical solution, with the disposal of the helical inclined pre-squeezing stripe, a thread-shaped indentation can be generated on the combination interface of the inner and outer shafts of the laminated shaft rolled in the first step, and the thread-shaped indentation can be destroyed in the secondary rolling of the shaping wedge, and the destroyed thread-shaped indentation can form circumferential and radial limitation dents on the combination interface of the inner and outer shafts so as to improve the circumferential and axial strength of the inner and outer shafts at the same time.

[0023] Preferably, the height that the shaping wedge protrudes out of the corresponding contact surface is greater than the height that the pre-squeezing stripe protrudes out of the corresponding contact surface.

[0024] In the above technical solution, when the shaping wedge performs squeeze-rolling on the laminated shaft, the wave generated by the pre-squeezing stripe on the outer shaft can be rolled flat and thus the finally-rolled laminated shaft has smooth and flat outer surface.

[0025] Preferably, 0°α10°.

[0026] In the above technical solution, with the disposal of the inclined pre-squeezing stripe, a thread-shaped indentation can be generated on the combination interface of the inner and outer shafts of the laminated shaft rolled in the first step, and the thread-shaped indentation can be destroyed in the secondary rolling of the shaping wedge, and the destroyed thread-shaped indentation can form circumferential and radial limitation dents on the combination interface of the inner and outer shafts so as to improve the circumferential and axial strength of the inner and outer shafts at the same time.

[0027] Preferably, the pre-squeezing stripes on the two cross rolling moulds are mutually matched so that helical grooves formed by the two pre-squeezing stripes on the laminated shaft are overlapped or connected head to tail.

[0028] In the above technical solution, during the rolling process of the laminated shaft, the inner and outer shafts can receive more uniform squeeze and action and thus the shapes of the helical grooves are more regular and more stable, helping to improve the mechanical engagement strength of the combination interface of the inner and outer shafts of the laminated shaft, advance the performance of the axial shear resistance and the circumferential twist resistance of the laminated shaft and heighten the entire quality and reliability of the laminated shaft.

[0029] Preferably, multiple pre-squeezing stripes are disposed and the multiple pre-squeezing stripes are paralleled and spaced apart.

[0030] In the above technical solution, multiple uniformly-distributed helical grooves can be formed on the laminated shaft, which increases a contact area and a number of the mechanical engagement points of the combination interface of the inner and outer shafts, so as to effectively increase a frictional force and a combination strength of the combination interface. In this way, the performances of the axial shear resistance and the circumferential twist resistance of the laminated shaft can be better improved. Furthermore, the multiple paralleled and spaced-apart pre-squeezing stripes can also make a pressure more uniformly distributed on the laminated shaft, reducing local stress concentration and improving the entire stability and durability of the laminated shaft.

[0031] Preferably, multiple pre-squeezing stripes form a pre-squeezing stripe group with a width less than or equal to a width of the widest span of the shaping wedge.

[0032] In the above technical solution, it is guaranteed that, in the rolling process, the shaping wedge can fully process the indentation generated by the pre-squeezing stripe on the outer shaft such that the indentation on the outer surface of the outer shaft can be more effectively rolled flat. Furthermore, the indentation on the outer surface can also be more smoothly transferred to the combination interface of the inner and outer shafts so as to form a combination interface having specific wave characteristics, helping to improve the entire quality and performance of the laminated shaft and making it more stable and more reliable in the use process.

[0033] Preferably, a front end of the pre-squeezing stripe is provided with a transitional stripe with its height increasing from front to back.

[0034] In the above technical solution, the laminated shaft can become more stable when entering the rolling process of the pre-squeezing stripe, reducing any possible damages resulting from sudden stress. The presence of the transitional stripe helps to gradually guide the laminated shaft to deform so that the indentation produced by the pre-squeezing stripe on the outer shaft is more uniform, thereby improving the rolling quality and combination interface stability of the laminated shaft.

[0035] Preferably, the shaping wedge comprises a shaping front portion and a shaping rear portion at a rear side of the shaping front portion; a width of the shaping front portion increases from an end away from the shaping rear portion to an end close to the shaping rear portion; a front side of the shaping front portion is provided with a transitional portion with a height increasing from an end away from the shaping front portion to an end close to the shaping front portion.

[0036] In the above technical solution, when rolling the laminated shaft, the shaping wedge can gradually increase its action force on the laminated shaft to enable the deformation of the laminated shaft to be more uniform, helping improve the flatness of the outer surface of the laminated shaft and the stability of the wave characteristics of the combination interface. Further, the design of the increasing width of the shaping front portion is also favorable for extending the service life of the shaping wedge and reducing wear.

[0037] There is also provided a cross wedge rolling device for rolling the laminated shaft, which comprises a fixing frame and the above cross wedge rolling mechanism. One of the two plate-type moulds is fixed to the fixing frame and the other is slidably connected with the fixing frame. The two plate-type moulds are disposed up and down, and the linear drive mechanism is mounted on the fixing frame.

[0038] In the above technical solution, since the two plate-type moulds are disposed up and down and movable relative to each other, the laminated shaft can be effectively clamped and rolled, which ensures the stability and accuracy of the rolling process.

[0039] There is also provided a cross wedge rolling device for rolling the laminated shaft, which comprises a machine frame, a positioning assembly and the above cross wedge rolling mechanism. The two cross rolling rollers are rotatably connected to the machine frame, the positioning assembly and the rotation drive mechanism are mounted on the machine frame, and the positioning assembly is disposed between the two cross rolling rollers.

[0040] In the above technical solution, when the laminated shaft is rolled, the laminated shaft is placed inside the positioning assembly between the two cross rolling rollers; therefore, when the rotation drive mechanism drives the cross rolling rollers to rotate, the laminated shaft can be maintained in the positioning assembly during the rolling process of the cross rolling rollers.

[0041] Preferably, the positioning assembly comprises a first clamping plate and a second clamping plate extending along an axial direction of the cross rolling rollers. The first clamping plate and the second clamping plate are disposed in a spacing between the two cross rolling rollers and mounted on the machine frame. An avoiding gap is reserved between the first clamping plate and the cross rolling rollers, and an avoiding gap is reserved between the second clamping plate and the cross rolling rollers. A positioning groove extending along an axial direction of the cross rolling rollers is disposed between the first clamping plate and the second clamping plate. At least one end of the positioning groove along the axial direction of the cross rolling rollers is disposed as opening.

[0042] In the above technical solution, the positioning groove can perform accurate positioning and limitation on the laminated shaft entering between the cross rolling rollers to ensure the positional stability of the laminated state during the rolling process. The disposal of the avoiding gaps can prevent the first clamping plate and the second clamping plate from interfering with the cross rolling rollers, ensuring normal operation of the cross rolling rollers. Furthermore, the structure is simple, reliable, and easy to mount and maintain, satisfying the production requirements effectively.

[0043] There is provided a cross wedge rolling method, which can comprise the following steps based on the above cross wedge rolling device:

[0044] at step S100, the inner and outer shafts of the laminated shaft prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;

[0045] at step S200, after completion of the welding, the assembled laminated shaft is sent into a heating furnace for heating;

[0046] at step S300, the heated laminated shaft is sent into the cross wedge rolling device and the two plate-type moulds tightly clamp the laminated shaft;

[0047] at step S400, the two plate-type moulds are moved toward each other to enable the laminated shaft to sequentially run over the pre-squeezing stripe and the shaping wedge; when the laminated shaft runs over the pre-squeezing stripe, an indentation is generated on the outer surface of the outer shaft while the indentation is transferred to the inner shaft; when the laminated shaft runs over the shaping wedge, the indentation on the outer surface of the outer shaft is rolled flat under the effect of the shaping wedge; at the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge to the combination interface of the inner and outer shafts; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the inner and outer shafts has wave characteristics;

[0048] at step S500, the formed laminated shaft is taken out.

[0049] In the above plate-type cross wedge rolling process method, assembling is completed by interference fit and then welding is carried out, which ensures the inner shaft and the outer shaft are closely combined prior to rolling. The assembled laminated shaft is sent into the heating furnace and heated to a proper rolling temperature, increasing the plasticity of the material. The heated laminated shaft is sent into the cross wedge rolling device, and the two plate-type moulds tightly clamp a bar so as to provide a stable clamping force for subsequent rolling process. The two plate-type moulds are moved toward each other to enable the laminated shaft to sequentially run over the pre-squeezing stripe and the shaping wedge. In this process, the indentation generated on the outer surface can be effectively transferred to the inner shaft and under the effect of the shaping wedge, the indentation on the outer surface of the outer shaft is rolled flat and further transferred to the combination interface of the inner and outer shafts. The finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the inner shaft and the outer shaft has wave characteristics. In this process method, the shape and the performance of the laminated shaft can be accurately controlled so as to improve the quality and stability of the laminated shaft. The laminated shaft with the helical wavy combination interface realizes the metallurgical combination and interface mechanical engagement under high-temperature rolling at the same time, and has the characteristics of axial shear resistance and circumferential twist resistance, satisfying the requirements of the practical applications. Further, the process method flow is clear and simple to operate, helping increase the production efficiency and lower the production costs.

[0050] There is further provided a cross wedge rolling method, which comprises the following steps based on the above cross wedge rolling device:

[0051] At step S100, the inner and outer shaft prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;

[0052] at step S200, after completion of the welding, the assembled laminated shaft is sent into a heating furnace for heating;

[0053] at step S300, the heated laminated shaft is sent into the cross wedge rolling device and positioned inside the positioning assembly;

[0054] at step S400, the rotation drive mechanism drives the cross rolling rollers to rotate to enable the laminated shaft to sequentially run over the pre-squeezing stripe and the shaping wedge. When the laminated shaft runs over the pre-squeezing stripe, an indentation is generated on the outer surface of the outer shaft while the indentation is transferred to the inner shaft; when the laminated shaft runs over the shaping wedge, the indentation on the outer surface of the outer shaft is rolled flat under the squeezing effect of the shaping wedge. At the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge to the combination interface of the inner and outer shafts. The finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the inner and outer shafts has wave characteristics;

[0055] at step S500, the formed laminated shaft is taken out from the positioning assembly.

[0056] In the above roller-type cross wedge rolling method, assembling is completed by interference fit and then welding is carried out, which ensures the inner shaft and the outer shaft are closely combined prior to rolling. The assembled laminated shaft is sent into the heating furnace and heated to a proper rolling temperature, increasing the plasticity of the material. The heated laminated shaft is sent into the roller-type cross wedge rolling device, and placed inside the positioning assembly between the two cross rolling rollers. The rotation drive mechanism drives the cross rolling rollers to rotate and the cylindrical surface of the laminated shaft firstly rolls over the pre-squeezing stripe and is squeezed by the pre-squeezing strip to leave an indentation on the outer surface of the outer shaft while transferring the indentation to the inner shaft, and next, the laminated shaft continues rolling over the shaping wedge and leaves the indentation on the outer surface of the outer shaft rolled flat under the squeezing effect of the shaping wedge; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge to the combination interface of the inner shaft and the outer shaft; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the outer shaft and the inner shaft has wave characteristics. Finally, the formed laminated shaft is taken down from the positioning assembly and a new unformed laminated shaft is placed into the positioning assembly again to continue the processing of the next part. The above technical solution can not only realize rolling on the laminated shaft under high temperature but also enable the combination interface of the outer and inner shafts of the rolled laminated shaft to have wavy mechanical engagement, making the formed laminated shaft have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing efficiency will not be affected. Besides, the cross rolling rollers can provide reliable support for the rolling arc surfaces, ensuring the structural strength and stability of the rolling arc surfaces and hence ensuring the quality stability of the formed products. Furthermore, the cross rolling rollers can rotate all the time along one direction without repeating operation, leading to higher processing efficiency.BRIEF DESCRIPTIONS OF THE DRAWINGS

[0057] FIG. 1 is a structural schematic diagram of a first solution of the present disclosure.

[0058] FIG. 2 is a front view of a local structure of a first solution of the present disclosure.

[0059] FIG. 3 is a schematic diagram of a local structure of a first solution of the present disclosure.

[0060] FIG. 4 is a structural schematic diagram illustrating a cross rolling arc plate in a first solution of the present disclosure.

[0061] FIG. 5 is a front view of a cross rolling arc plate in a first solution of the present disclosure.

[0062] FIG. 6 is a left view of a cross rolling arc plate in a first solution of the present disclosure.

[0063] FIG. 7 is a schematic diagram illustrating a corresponding structure of each formation stage of a laminated shaft in a first solution of the present disclosure.

[0064] FIG. 8 is a schematic diagram of a structure prior to formation of a laminated shaft of the present disclosure.

[0065] FIG. 9 is a schematic diagram illustrating a structure subsequent to formation of a laminated shaft by a pre-squeezing stripe in the present disclosure.

[0066] FIG. 10 is a schematic diagram illustrating a structure subsequent to formation of a laminated shaft by a shaping wedge in the present disclosure.

[0067] FIG. 11 is a structural schematic diagram of a second solution of the present disclosure.

[0068] FIG. 12 is a schematic diagram of a local structure of a second solution of the present disclosure.

[0069] FIG. 13 is a front view of a local structure of a second solution of the present disclosure.

[0070] FIG. 14 is a structural schematic diagram of a plate-type mould in a second solution of the present disclosure.

[0071] FIG. 15 is a front view of a plate-type mould in a second solution of the present disclosure.

[0072] FIG. 16 is a top view of a plate-type mould in a second solution of the present disclosure.

[0073] FIG. 17 is a schematic diagram illustrating a corresponding structure of each formation stage of a laminated shaft in a second solution of the present disclosure.NUMERALS OF DRAWINGS ARE DESCRIBED BELOW1. cross rolling mould, 11. plate-type mould, 12. cross rolling roller, 121. roller body, 122. cross rolling arc plate, 2. contact surface, 21. support surface, 22. rolling arc surface, 3. pre-squeezing stripe, 4. shaping wedge, 41. shaping front portion, 42. shaping rear portion, 43. transitional portion, 5. transitional stripe, 6. laminated shaft, 61. inner shaft, 62. outer shaft, 63. helical groove, 7. positioning assembly, 71. first clamping plate, 72. second clamping plate, 73. positioning groove, 8. drive mechanism, 81. linear drive mechanism, 82. rotation drive mechanism, 9. fixing frame and 10. machine frame.DETAILED DESCRIPTIONS OF EMBODIMENTS

[0075] The present disclosure will be further described below in combination with specific embodiments and drawings.

[0076] As shown in FIGS. 1 to 17, there is provided a cross wedge rolling mechanism for rolling a laminated shaft, which comprises a drive mechanism 8 and two paralleled and opposed cross rolling moulds 1. The drive mechanism is in transmission connection with at least one cross rolling mould 1 and drives the cross rolling mould 1 to move. A contact surface 2 in contact with the laminated shaft 6 is disposed on the cross rolling moulds 1. A pre-squeezing stripe 3 protruding out of the contact surface 2 is disposed on the contact surface 2 of at least one cross rolling mould 1. A shaping wedge 4 protruding out of the contact surface 2 is disposed on the contact surface 2 of the at least one cross rolling mould 1. An included angle α of an extending direction of the pre-squeezing stripe 3 and a moving direction of the cross rolling mould 1 is less than 45°. The pre-squeezing stripe 3 is disposed in front of the shaping wedge 4 such that the laminated shaft 6 can sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4 during moulding.

[0077] In the above technical solution, the laminated shaft 6 is composed of an inner shaft 61 and an outer shaft 62 sleeved outside the inner shaft 61; the inner shaft 61 and the outer shaft 62 are fixed by close fit and end welding. The pre-squeezing stripe 3 and the shaping wedge 4 can be disposed as different shapes and sizes based on requirements of actual products. The working principle of the solution is as below: the laminated shaft 6 is placed between the two cross rolling moulds 1 and the two cross rolling moulds 1 are located at opposed sides of the laminated shaft 6 and then driven by the drive mechanism 8 to move; during the movement process of the cross rolling moulds 1, the laminated shaft 6 rolls relative to the two cross rolling moulds 1. A cylindrical surface of the laminated shaft 6 firstly rolls over the pre-squeezing stripe 3 and is squeezed by the pre-squeezing stripe 3 to leave an indentation on an outer surface of the outer shaft 62 while transferring the indentation to the inner shaft 61, and next, the laminated shaft 6 continues rolling over the shaping wedge 4 and leaves the indentation on the outer surface of the outer shaft 62 rolled flat under the squeezing effect of the shaping wedge 4; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to a combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the outer shaft 62 and the inner shaft 61 has wave characteristics. The above technical solution can not only realize rolling on the laminated shaft 6 under high temperature but also enable the combination interface of the outer shaft 62 and the inner shaft 61 of the rolled laminated shaft 6 to have wavy mechanical engagement, making the formed laminated shaft 6 have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft 6 can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing costs will not be increased.Embodiment 1

[0078] As shown in FIGS. 8 to 17, there is provided a cross wedge rolling mechanism for rolling a laminated shaft, which comprises a linear drive mechanism 81 and two paralleled and opposed plate-type moulds 11. The linear drive mechanism 81 is connected with at least one plate-type mould 11 such that the two plate-type moulds 11 can translate toward each other. A support surface 21 abutting against the laminated shaft 6 is disposed on the plate-type moulds 11 respectively. A pre-squeezing stripe 3 protruding out of the support surface 21 is disposed on at least one support surface 21, and a shaping wedge 4 protruding out of the support surface 21 is disposed on at least one support surface 21. An included angle αbetween an extending direction of the pre-squeezing stripe 3 and a moving direction of the plate-type mould 11 is less than 45°. The pre-squeezing stripe 3 extends substantially along the moving direction of the plate-type mould 11, and the shaping wedge 4 extends along the moving direction of the plate-type mould 11. The pre-squeezing stripe 3 is disposed in front of the shaping wedge 4 such that the laminated shaft 6 can sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4 during moulding. The X direction shown herein refers to a relative movement direction of the plate-type moulds 11.

[0079] In this embodiment, as shown in FIGS. 8 to 17, the laminated shaft 6 is composed of an inner shaft 61 and an outer shaft 62 sleeved outside the inner shaft 61; the inner shaft 61 and the outer shaft 62 are made of different materials. Prior to rolling, the inner shaft 61 and the outer shaft 62 are fixed by close fit and end welding, and after rolling, the outer shaft 62 changes in shape into a desired part shape.

[0080] In the above technical solution, the pre-squeezing stripe 3 and the shaping wedge 4 can be disposed as different shapes and sizes based on requirements of actual products. The working principle of the solution is as below: the laminated shaft 6 is placed between the two plate-type moulds 11 and clamped on both sides by the two plate-type moulds 11, and then the linear drive mechanism 81 drives the two plate-type moulds 11 to translate toward each other; in the translation process, the laminated shaft 6 rolls relative to the two plate-type moulds 11. The cylindrical surface of the laminated shaft 6 firstly rolls over the pre-squeezing stripe 3 and is squeezed by the pre-squeezing stripe 3 to leave an indentation on an outer surface of the outer shaft 62 while transferring the indentation to the inner shaft 61, and next, the laminated shaft 6 continues rolling over the shaping wedge 4 and leaves the indentation on the outer surface of the outer shaft 62 rolled flat under the squeezing effect of the shaping wedge 4; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to a combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the outer shaft 62 and the inner shaft 61 has wave characteristics. The above technical solution can not only realize rolling on the laminated shaft 6 under high temperature but also enable the combination interface of the outer shaft 62 and inner shaft 61 of the rolled laminated shaft 6 to have wavy mechanical engagement, making the formed laminated shaft 6 have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft 6 can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing costs will not be increased.

[0081] Preferably, as shown in FIG. 14, a front end of the pre-squeezing stripe 3 is provided with a transitional stripe 5 with its height increasing from front to back. The shaping wedge 4 comprises a shaping front portion 41 and a shaping rear portion 42 at a rear side of the shaping front portion 41; a width of the shaping front portion 41 increases from an end away from the shaping rear portion 42 to an end close to the shaping rear portion 42; a front side of the shaping front portion 41 is provided with a transitional portion 43 with a height increasing from an end away from the shaping front portion 41 to an end close to the shaping front portion 41.

[0082] In the above technical solution, the laminated shaft 6 can become more stable when entering the rolling process of the pre-squeezing stripe 3, reducing any possible damages resulting from sudden stress. The presence of the transitional stripe 5 helps to gradually guide the laminated shaft 6 to deform so that the indentation produced by the pre-squeezing stripe 3 on the outer shaft 62 is more uniform, thereby improving the rolling quality and combination interface stability of the laminated shaft 6. When rolling the laminated shaft 6, the shaping wedge 4 can gradually increase its action force on the laminated shaft 6 to enable the deformation of the laminated shaft 6 to be more uniform, helping improve the flatness of the outer surface of the laminated shaft 6 and the stability of the wave characteristics of the combination interface. Further, the design of the increasing width of the shaping front portion 41 is also favorable for extending the service life of the shaping wedge 4 and reducing wear. The transitional portion 43 in the front of the shaping front portion 41 can achieve buffering effect when the laminated shaft 6 comes in contact with the shaping wedge 4, making the stress received by the laminated shaft 6 more uniform. This helps improve the rolling quality of the laminated shaft 6 and lower the possibility of occurrence of defects in the rolling process of the laminated shaft 6, further intensifying the entire performance and reliability of the laminated shaft 6.

[0083] In this embodiment, in order to enable the two plate-type moulds 11 to translate toward each other, one of the two plate-type moulds 11 can be fixed and the other plate-type mould 11 is driven to translate by the linear drive mechanism 81; or, the linear drive mechanism 81 can also drive the two plate-type moulds 11 to move in opposite directions simultaneously.

[0084] In this embodiment, the two plate-type moulds 11 can be disposed up and down or opposed left and right.

[0085] It can be understood that, in this embodiment, the pre-squeezing stripe 3 and the shaping wedge 4 can be arranged in the following manners: in a first manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one support surface 21 are disposed on the one support surface 21 at the same time; in a second manner, a pre-squeezing stripe 3 protruding out of one support surface 21 is disposed on the one support surface 21 and a shaping wedge 4 protruding out of the other support surface 21 is disposed on the other support surface 21; in a third manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of each of the two support surfaces 21 are disposed on the corresponding support surface 21 at the same time; in a fourth manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one support surface 21 are disposed on the one support surface 21 at the same time and a pre-squeezing stripe 3 protruding out of the other support surface 21 is disposed on the other support surface 21; in a fifth manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one support surface 21 are disposed on the one support surface 21 at the same time, and a shaping wedge 4 protruding out of the other support surface 21 is disposed on the other support surface 21. Regardless of what arrangement, it is always required to ensure when the laminated shaft 6 is formed, the laminated shaft 6 sequentially runs over the pre-squeezing stripe 3 and the shaping wedge 4.

[0086] Preferably, as shown in FIGS. 15 to 17, a height h1 that the shaping wedge 4 protrudes out of the corresponding support surface 21 is greater than a height h2 that the pre-squeezing stripe 3 protrudes out of the corresponding support surface 21. In the above technical solution, when the shaping wedge 4 performs squeeze-rolling on the laminated shaft 6, the wave generated by the pre-squeezing stripe 3 on the outer shaft 6 can be rolled flat and the finally-rolled laminated shaft 6 has a smooth and flat outer surface.

[0087] It can be understood that, in another embodiment, if there is no requirement for the flatness of the outer surface of the formed outer shaft 62, the height that the shaping wedge 4 protrudes out of the corresponding support surface 21 is made no greater than the height that the pre-squeezing stripe 3 protrudes out of the corresponding support surface 21.Embodiment 2

[0088] As shown in FIG. 16, on the basis of the embodiment 1, the included angle α between the extending direction of the pre-squeezing stripe 3 and the moving direction of the plate-type mould 11 is 0°α20° and preferably is 10°.

[0089] In the above technical solution, with the disposal of the inclined pre-squeezing stripe 3, a thread-shaped indentation can be generated on the combination interface of the inner shaft 61 and the outer shaft 62 of the laminated shaft 6 rolled in the first step, and the thread-shaped indentation can be destroyed in the secondary rolling of the shaping wedge 4, and the destroyed thread-shaped indentation can form circumferential and radial limitation dents on the combination interface of the inner shaft 61 and the outer shaft 62 so as to improve the circumferential and axial strength of the inner shaft 61 and the outer shaft 62 at the same time. The excessive inclination angle may lead to non-smoothness of the formation of the laminated shaft 6. Therefore, the included angle αshall not be too large.

[0090] Preferably, as shown in FIGS. 8 to 17, when the pre-squeezing stripe 3 is disposed on the two support surfaces 21 respectively, the pre-squeezing stripes on the two plate-type moulds 11 are mutually matched, such that the helical grooves 63 formed by the two pre-squeezing stripes on the laminated shaft 6 are overlapped or connected head to tail. In the above technical solution, when the laminated shaft is rolled, the inner shaft 61 and the outer shaft 62 can receive more uniform squeeze and action, making the shape of the helical grooves 63 more regular and more stable, and helping increase the mechanical engagement strength of the combination interface of the inner shaft 61 and the outer shaft 62 of the laminated shaft 6, intensifying the performance of the laminated shaft in axial shear resistance and circumferential twist resistance and improving the entire quality and reliability of the laminated shaft 6.Embodiment 3

[0091] As shown in FIGS. 14 and 17, on the basis of the embodiments 1 and 2, multiple pre-squeezing stripes 3 may be disposed, and the multiple pre-squeezing stripes 3 are paralleled and spaced apart. Multiple pre-squeezing stripes 3 form a pre-squeezing stripe group with a width L1 less than or equal to a width L2 of the widest span of the shaping wedge 4.

[0092] In the above technical solution, multiple uniformly-distributed helical grooves 63 can be formed on the laminated shaft 6, which increases a contact area and a number of the mechanical engagement points of the combination interface of the inner shaft 61 and the outer shaft 62, so as to effectively increase a frictional force and a combination strength of the combination interface. In this way, the performances of the axial shear resistance and the circumferential twist resistance of the laminated shaft can be better improved. Furthermore, the multiple paralleled and spaced-apart pre-squeezing stripes 3 can also make a pressure more uniformly distributed on the laminated shaft 6, reducing local stress concentration and improving the entire stability and durability of the laminated shaft 6. When the width of the pre-squeezing stripe group is less than or equal to the width of the widest span of the shaping wedge 4, it can be guaranteed that in the rolling process, the shaping wedge 4 can fully process the indentation generated by the pre-squeezing stripe 3 on the outer shaft 62 so that the indentation on the outer surface of the outer shaft 62 can be more effectively rolled flat. Meanwhile the indentation on the outer surface can be more smoothly transferred to the combination interface of the inner shaft 61 and the outer shaft 62, so as to form the combination interface with specific wave characteristics. This helps to improve the entire quality and performance of the laminated shaft 6, making it more stable and reliable in use.Embodiment 4

[0093] As shown in FIGS. 8 to 17, there is provided a cross wedge rolling device for rolling a laminated shaft, which comprises a fixing frame 9 and the cross wedge rolling mechanism mentioned in the embodiments 1 to 3. One of the two plate-type moulds 11 is fixed to the fixing frame 9 and the other is slidably connected with the fixing frame 9. The two plate-type moulds 11 are disposed up and down, and the linear drive mechanism 81 is mounted on the fixing frame 9.

[0094] In the above technical solution, since the two plate-type moulds 11 are disposed up and down and movable relative to each other, the laminated shaft 6 can be effectively clamped and rolled, which ensures the stability and accuracy of the rolling process.Embodiment 5

[0095] There is provided a cross wedge rolling method, which, based on the cross wedge rolling device mentioned in the above embodiment 4, includes the following steps:

[0096] at step S100, the inner shaft 61 and the outer shaft 62 of the laminated shaft 6 prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;

[0097] at step S200, after completion of the welding, the assembled laminated shaft 6 is sent into a heating furnace for heating;

[0098] at step S300, the heated laminated shaft 6 is sent into the cross wedge rolling device and the two plate-type moulds 11 tightly clamp the laminated shaft 6;

[0099] at step S400, the two plate-type moulds 11 are moved toward each other to enable the laminated shaft 6 to sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4; when the laminated shaft 6 runs over the pre-squeezing stripe 3, an indentation is generated on the outer surface of the outer shaft 62 while the indentation is transferred to the inner shaft 61; when the laminated shaft 6 runs over the shaping wedge 4, the indentation on the outer surface of the outer shaft 62 is rolled flat under the effect of the shaping wedge 4; at the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to the combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the inner shaft 61 and the outer shaft 62 has wave characteristics;

[0100] at step S500, the formed laminated shaft 6 is taken out.

[0101] In the above cross wedge rolling method, assembling is completed by interference fit and then welding is carried out, which ensures the inner shaft 61 and the outer shaft 62 are closely combined prior to rolling. The assembled laminated shaft 6 is sent into the heating furnace and heated to a proper rolling temperature, increasing the plasticity of the material. The heated laminated shaft 6 is sent into the cross wedge rolling device, and the two plate-type moulds 11 tightly clamp a bar so as to provide a stable clamping force for subsequent rolling process. The two plate-type moulds 11 are moved toward each other to enable the laminated shaft 6 to sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4. In this process, the indentation generated on the outer surface of the outer shaft 62 can be effectively transferred to the inner shaft 61 and under the effect of the shaping wedge 4, the indentation on the outer surface of the outer shaft 62 is rolled flat and further transferred to the combination interface of the inner shaft 61 and the outer shaft 62. The finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the inner shaft 61 and the outer shaft 62 has wave characteristics. In this process method, the shape and the performance of the laminated shaft 6 can be accurately controlled so as to improve the quality and stability of the laminated shaft 6. The laminated shaft 6 with the helical wavy combination interface realizes the metallurgical combination and interface mechanical engagement under high-temperature rolling at the same time, and has the characteristics of axial shear resistance and circumferential twist resistance, satisfying the requirements of the practical applications. Further, the process method flow is clear and simple to operate, helping increase the production efficiency and lower the production costs.Embodiment 6

[0102] As shown in FIGS. 1 to 10, there is provided a cross wedge rolling mechanism for rolling a laminated shaft, which comprises a rotation drive mechanism 82 and two paralleled and opposed cross rolling rollers 12. The two cross rolling rollers 12 rotate in opposite directions, and the rotation drive mechanism 82 is in transmission connection with at least one of the two cross rolling rollers 12 and drives the cross rolling roller 12 to rotate. A pre-squeezing stripe 3 protruding out of a rolling arc surface 22 is disposed on the rolling arc surface 22 of at least one cross rolling roller 12, and a shaping wedge 4 protruding out of the rolling arc surface 22 is disposed on the rolling arc surface 22 of at least one cross rolling roller 12. The pre-squeezing stripe 4 extends along a peripheral direction of the cross rolling roller 12, and the shaping wedge 4 extends along a rotation direction of the cross rolling roller 12. The pre-squeezing stripe 3 is disposed in front of the shaping wedge 4 such that the laminated shaft 6 can, during moulding, sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4.

[0103] In this embodiment, as shown in FIGS. 8 to 10, the laminated shaft 6 is composed of an inner shaft 61 and an outer shaft 62 sleeved outside the inner shaft 61; the inner shaft 61 and the outer shaft 62 are made of different materials. Prior to rolling, the inner shaft 61 and the outer shaft 62 are fixed by close fit and end welding, and after rolling, the outer shaft 62 changes in shape into a desired part shape.

[0104] In the above technical solution, the pre-squeezing stripe 3 and the shaping wedge 4 can be disposed as different shapes and sizes based on requirements of actual products. The working principle of the solution is as below: the laminated shaft 6 is placed between the two cross rolling rollers 12, and the two cross rolling rollers 12 are rotated by the rotation drive mechanism 82 while the laminated shaft 6 is rotated between the cross rolling rollers 12. When the cross rolling rollers 12 rotate, a cylindrical surface of the laminated shaft 6 firstly rolls over the pre-squeezing stripe 3 and is squeezed by the pre-squeezing stripe 3 to leave an indentation on an outer surface of the outer shaft 62 while transferring the indentation to the inner shaft 61, and next, the laminated shaft 6 continues rolling over the shaping wedge 4 and leaves the indentation on the outer surface of the outer shaft 62 rolled flat under the squeezing effect of the shaping wedge 4; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to a combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the outer shaft 62 and the inner shaft 61 has wavy characteristics. Finally, the formed laminated shaft 6 is taken down to continue the processing of a next part. The above technical solution can not only realize rolling on the laminated shaft 6 under high temperature but also enable the combination interface of the outer and inner shafts 62 and 61 of the rolled laminated shaft 6 to have wavy mechanical engagement, making the formed laminated shaft 6 have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft 6 can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing efficiency will not be affected. Besides, the cross rolling rollers 12 can provide reliable support for the rolling arc surfaces 22, ensuring the structural strength and stability of the rolling arc surfaces 22 and hence ensuring the quality stability of the formed products. Furthermore, the cross rolling rollers 12 can rotate all the time along one direction without repeating operation, leading to higher processing efficiency. The Y direction shown herein refers to the rotation direction of the cross rolling rollers 12.

[0105] Preferably, as shown in FIG. 4, a front end of the pre-squeezing stripe 3 is provided with a transitional stripe 5 with its height increasing from front to back. The shaping wedge 4 comprises a shaping front portion 41 and a shaping rear portion 42 at a rear side of the shaping front portion 41; a width of the shaping front portion 41 increases from an end away from the shaping rear portion 42 to an end close to the shaping rear portion 42; a front side of the shaping front portion 41 is provided with a transitional portion 43 with a height increasing from an end away from the shaping front portion 41 to an end close to the shaping front portion 41.

[0106] In the above technical solution, the laminated shaft 6 can become more stable when entering the rolling process of the pre-squeezing stripe 3, reducing any possible damages resulting from sudden stress. The presence of the transitional stripe 5 helps to gradually guide the laminated shaft 6 to deform so that the indentation produced by the pre-squeezing stripe 3 on the outer shaft 62 is more uniform, thereby improving the rolling quality and combination interface stability of the laminated shaft 6. When rolling the laminated shaft 6, the shaping wedge 4 can gradually increase its action force on the laminated shaft 6 to enable the deformation of the laminated shaft 6 to be more uniform, helping improve the flatness of the outer surface of the laminated shaft 6 and the stability of the wave characteristics of the combination interface. Further, the design of the increasing width of the shaping front portion 41 is also favorable for extending the service life of the shaping wedge 4 and reducing wear. The transitional portion 43 in the front of the shaping front portion 41 can achieve buffering effect when the laminated shaft 6 comes in contact with the shaping wedge 4, making the stress received by the laminated shaft 6 more uniform. This helps improve the rolling quality of the laminated shaft 6 and lower the possibility of occurrence of defects in the rolling process of the laminated shaft 6, further intensifying the entire performance and reliability of the laminated shaft 6.Embodiment 7

[0107] As shown in FIGS. 1 to 10, there is provided a cross wedge rolling device for rolling a laminated shaft, which comprises a machine frame 10, a positioning assembly 7 and the cross wedge rolling mechanism mentioned in the embodiment 6. Two cross rolling rollers 12 are rotatably connected to the machine frame 10 and can rotate in opposite directions. The positioning assembly 7 and the rotation drive mechanism 82 are mounted on the machine frame 10. The rotation drive mechanism 82 is in transmission connection with at least one of the two cross rolling rollers 12 and drives the cross rolling roller 12 to rotate. The positioning assembly 7 is disposed between the two cross rolling rollers 12.

[0108] In the above technical solution, the pre-squeezing stripe 3 and the shaping wedge 4 can be disposed as different shapes and sizes based on the requirements of actual products. The working principle of the solution is as follows: the laminated shaft 6 is located inside the positioning assembly 7 between the two cross rolling rollers 12; when the rotation drive mechanism 82 drives the cross rolling rollers 12 to rotate, the laminated shaft 6 can be maintained in the positioning assembly 7 during the rolling process of the cross rolling rollers 12. When the cross rolling rollers 12 rotate, a cylindrical surface of the laminated shaft 6 firstly rolls over the pre-squeezing stripe 3 and is squeezed by the pre-squeezing stripe 3 to leave an indentation on an outer surface of the outer shaft 62 while transferring the indentation to the inner shaft 61, and next, the laminated shaft 6 continues rolling over the shaping wedge 4 and leaves the indentation on the outer surface of the outer shaft 62 rolled flat under the squeezing effect of the shaping wedge 4; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to a combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the outer shaft 62 and the inner shaft 61 has wavy characteristics. Finally, the formed laminated shaft 6 is taken down from the positioning assembly 7 and a new unformed laminated shaft 6 is placed again into the positioning assembly 7 to continue the processing of a next part. The above technical solution can not only realize rolling on the laminated shaft 6 under high temperature but also enable the combination interface of the outer and inner shafts 62 and 61 of the rolled laminated shaft 6 to have wavy mechanical engagement, making the formed laminated shaft 6 have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft6 can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing efficiency will not be affected. Besides, the cross rolling rollers 12 can provide reliable support for the rolling arc surfaces 22, ensuring the structural strength and stability of the rolling arc surfaces 22 and hence ensuring the quality stability of the formed products. Furthermore, the cross rolling rollers 12 can rotate all the time along one direction without repeating operation, leading to higher processing efficiency. The machine frame 10 and the rotation drive mechanism 82 are not shown herein.

[0109] It can be understood that in one embodiment, the machine frame 10 is provided with a gear transmission mechanism which comprises one input end and two output ends. An output end of the rotation drive mechanism 82 is connected with the input end of the gear transmission mechanism, and the two output ends of the gear transmission mechanism are respectively connected to the two cross rolling rollers 12 to enable the two cross rolling rollers 12 to synchronously and reversely rotate. In the above solution, one rotation drive mechanism 82 can drive two cross rolling rollers 12 to synchronously and reversely rotate.

[0110] It can be understood that in another embodiment, two rotation drive mechanisms 82 may be disposed and the two rotation drive mechanisms 82 respectively drive the two cross rolling rollers 12 to rotate.

[0111] In this embodiment, the two cross rolling rollers 12 can be disposed up and down or opposed left and right.

[0112] It can be understood that in this embodiment, the pre-squeezing stripe 3 and the shaping wedge 4 can be arranged in the following manners: in a first manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one rolling arc surface 22 are disposed on the one rolling arc surface 22 at the same time; in a second manner, a pre-squeezing stripe 3 protruding out of one rolling arc surface 22 is disposed on the one rolling arc surface 22 and a shaping wedge 4 protruding out of the other rolling arc surface 22 is disposed on the other rolling arc surface 22; in a third manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of each of the two rolling arc surfaces 22 are disposed on the corresponding rolling arc surface 22 at the same time; in a fourth manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one rolling arc surface 22 are disposed on the one rolling arc surface 22 at the same time and a pre-squeezing stripe 3 protruding out of the other rolling arc surface 22 is disposed on the other rolling arc surface 22; in a fifth manner, a pre-squeezing stripe 3 and a shaping wedge 4 protruding out of one rolling arc surface 22 are disposed on the one rolling arc surface 22 at the same time, and a shaping wedge 4 protruding out of the other rolling arc surface 22 is disposed on the other rolling arc surface 22. Regardless of what arrangement, it is always required to ensure when the laminated shaft 6 is formed, the laminated shaft 6 sequentially runs over the pre-squeezing stripe 3 and the shaping wedge 4.

[0113] It can be understood that in one embodiment, the height h1 that the shaping wedge 4 protrudes out of the corresponding rolling arc surface 22 is greater than the height h2 that the pre-squeezing stripe 3 protrudes out of the corresponding rolling arc surface 22. In the above technical solution, when rolling the laminated shaft 6, the shaping wedge 4 can roll flat the wave generated by the pre-squeezing stripe 3 on the outer shaft 62 and thus the finally-rolled laminated shaft 6 has a smooth and flat outer surface.

[0114] It can be understood that in another embodiment, if there is no requirement for the flatness of the outer surface of the formed outer shaft 62, the height that the shaping wedge 4 protrudes out of the corresponding rolling arc surface 22 is made no greater than the height that the pre-squeezing stripe 3 protrudes out of the corresponding rolling arc surface 22.

[0115] Preferably, as shown in FIG. 3, the positioning assembly 7 comprises a first clamping plate 71 and a second clamping plate 72 extending along an axial direction of the cross rolling rollers 12. The first clamping plate 71 and the second clamping plate 72 are disposed in a spacing between the two cross rolling rollers 12 and mounted on the machine frame 10. An avoiding gap is reserved between the first clamping plate 71 and the cross rolling rollers 12, and an avoiding gap is reserved between the second clamping plate 72 and the cross rolling rollers 12. A positioning groove 73 extending along an axial direction of the cross rolling rollers 12 is disposed between the first clamping plate 71 and the second clamping plate 72. At least one end of the positioning groove 73 along the axial direction of the cross rolling rollers 12 is disposed as opening.

[0116] In the above technical solution, the positioning groove 73 can perform accurate positioning and limitation on the laminated shaft 6 entering between the cross rolling rollers 12 to ensure the positional stability of the laminated state 6 during the rolling process. The disposal of the avoiding gaps can prevent the first clamping plate 71 and the second clamping plate 72 from interfering with the cross rolling rollers 12, ensuring normal operation of the cross rolling rollers 12. Furthermore, the structure is simple, reliable, and easy to mount and maintain, satisfying the production requirements effectively.

[0117] It can be understood that in one embodiment, designing one end of the positioning groove 73 as opening along the axial direction of the cross rolling rollers 12 facilitates putting in or taking out the laminated shaft 6 from the opening position.

[0118] It can be understood that in another embodiment, both ends of the positioning groove 73 along the axial direction of the cross rolling rollers 12 are designed as opening such that when the laminated shaft 6 is already placed from one opening, a new laminated shaft 6 can be put in to push the laminated shaft 6 from the other opening into a product recovery device, helping put in and take out the laminated shaft 6, and increasing the production efficiency.Embodiment 8

[0119] On the basis of the embodiment 7, as shown in FIGS. 2 to 10, only one cross rolling roller 12 comprises a roller body 121 and a cross rolling arc plate 122 detachably disposed on the cylindrical surface of the roller body 121. The cross rolling arc plate 122 partially wraps the roller body 121 along a circumferential direction of the cross rolling roller 12 and protrudes out of the cylindrical surface of the roller body 121; the rolling arc surface 22 is disposed on the cross rolling arc plate 122. The height that the rolling arc surface 22 in the cross rolling arc plate 122 protrudes out of the cylindrical surface of the roller body 121 is H0. A transitional surface transitioning from the cylindrical surface of the corresponding roller body 121 to the rolling arc surface 22 on the cross rolling arc plate 122 is disposed on the cross rolling arc plate 122. The radiuses of the two cross rolling rollers 12 are R1 and R2 respectively, a distance between axes of the two cross rolling rollers 12 is L, and an outer diameter of the laminated shaft 6 is D1, where R1+R2+D1≤L≤H0+R1+R2+D1.

[0120] In the above technical solution, the detachable mounting of the cross rolling arc plate 122 makes its processing more flexible and thus the cross rolling arc plate 122 can be separately processed, increasing the processing efficiency and accuracy. In this way, the processing difficulty is reduced and the entire processing cost is lowered. Further, a cross rolling arc plate 122 with corresponding model can be used based on a different size of the laminated shaft 6, increasing the universality and adaptability of the cross rolling roller 12 and satisfying the diversified production requirements. In the above technical solution, with R1+R2+D1≤L, when the rolling arc surface 22 is not aligned with the laminated shaft 6, the laminated shaft 6 is not in contact with the cylindrical surface of the cross rolling roller 12, helping put in or take out the laminated shaft 6. With L≤H0+R1+R2+D1, when the cross rolling roller 12 rotates to facing toward the laminated shaft 6, the rolling arc surface 22 can closely press the laminated shaft 6 such that the rolling arc surface 22 can effectively bring the laminated shaft 6 to rotate and process it into a desired shape while limiting and ensuring the outer diameter of the processed laminated shaft 6. The transitional surface can enable the cylindrical surface to correspondingly transition from the cylindrical surface of the roller body 121 to and abut against the rolling arc surface 22 smoothly.Embodiment 9

[0121] On the basis of the embodiment 7, as shown in FIGS. 1 to 10, each of the two cross rolling rollers 12 comprises a roller body 121 and a cross rolling arc plate 122 detachably mounted on the cylindrical surface of the roller body 121. The cross rolling arc plate 122 partially wraps the roller body 121 along the circumferential direction of the cross rolling roller 12 and protrudes out of the cylindrical surface of the roller body 121. The rolling arc surface 22 is disposed on the cross rolling arc plates 122. The sum of the heights that the two rolling arc surfaces 22 protrude out of the cylindrical surface of the corresponding roller bodies 121 is H0. A transitional surface transitioning from the cylindrical surface of the corresponding roller body 121 to the rolling arc surface 22 on the cross rolling arc plate 122 is disposed on the cross rolling arc plate 122. The radiuses of the two cross rolling rollers 12 are R1 and R2 respectively, a distance between axes of the two cross rolling rollers 12 is L, and an outer diameter of the laminated shaft 6 is D1, where R1+R2+D1≤L≤H0+R1+R2+D1.

[0122] In the above technical solution, the detachable mounting of the cross rolling arc plate 122 makes its processing more flexible and thus the cross rolling arc plate 122 can be processed separately, increasing the processing efficiency and accuracy. In this way, the processing difficulty is reduced and the entire processing cost is lowered. Further, a cross rolling arc plate 122 with corresponding model can be used based on a different size of the laminated shaft 6, increasing the universality and adaptability of the cross rolling roller 12 and satisfying the diversified production requirements. With R1+R2+D1≤L, when the rolling arc surface 22 is not aligned with the laminated shaft 6, the laminated shaft 6 is not in contact with the cylindrical surface of the cross rolling roller 12, helping put in or take out the laminated shaft 6. With L≤H0+R1+R2+D1, when the cross rolling roller 12 rotates to facing toward the laminated shaft 6, the rolling arc surface 22 can closely press the laminated shaft 6 such that the rolling arc surface 22 can effectively bring the laminated shaft 6 to rotate and process it into a desired shape while limiting and ensuring the outer diameter of the processed laminated shaft 6. The transitional surface can enable the cylindrical surface to correspondingly transition from the cylindrical surface of the roller body 121 to and abut against the rolling arc surface 22 smoothly.Embodiment 10

[0123] On the basis of the embodiment 7, as shown in FIGS. 1 to 10, distances of the two rolling arc surfaces 22 from the axes of the corresponding cross rolling rollers 12 are L1 and L2, a distance between the axes of the two cross rolling rollers 12 is L, and an outer diameter of the laminated shaft 6 is D1, where L1+L2+D1≤L;

[0124] when the pre-squeezing stripe 3 is disposed on the rolling arc surface 22 of only one cross rolling roller 12, the height that the pre-squeezing stripe 3 protrudes out of the corresponding rolling arc surface 22 is H1, where H1+L1+L2+D1≥L;

[0125] when the pre-squeezing stripe 3 is disposed on the rolling arc surface 22 of each of the two cross rolling rollers 12, the heights that the two pre-squeezing stripes 3 protrude out of the corresponding the rolling arc surfaces 22 are H1 and H2, where H1+H2+L1+L2+D1≥L;

[0126] when the shaping wedge 4 is disposed on the rolling arc surface 22 of only one cross rolling roller 12, the height that the shaping wedge 4 protrudes out of the corresponding rolling arc surface 22 is H3, where H3+L1+L2+D1≥L;

[0127] when the shaping wedge 4 is disposed on the rolling arc surface 22 of each of the two cross rolling rollers 12, the heights that the two shaping wedges 4 protrude out of the corresponding the rolling arc surfaces 22 are H3 and H4, where H3+H4+L1+L2+D1≥L.

[0128] In the above technical solution, with L1+L2+D1≤L, when the pre-squeezing stripe 3 or the shaping wedge 4 is not aligned with the laminated shaft 6, the laminated shaft 6 is not in contact with the cylindrical surface of the cross rolling roller 12 and the rolling arc surface 22, helping put in and take out the laminated shaft 6. When the pre-squeezing stripe 3 or the shaping wedge 4 is aligned with the laminated shaft 6, the pre-squeezing stripe 3 or the shaping wedge 4 can be tightly pressed onto the laminated shaft 6 such that the pre-squeezing stripe 3 or the shaping wedge 4 can effectively bring the laminated shaft 6 to rotate and process it into a desired shape.Embodiment 11

[0129] As shown in FIG. 5, on the basis of the embodiment 7, the pre-squeezing stripe 3 extends helically along a peripheral direction of the cross rolling roller 12, and a helical angle of the pre-squeezing stripe 3 is β, where β=90°−α and 80°β90°.

[0130] In the above technical solution, with the disposal of the helical inclined pre-squeezing stripe 3, a thread-shaped indentation can be generated on the combination interface of the inner shaft 61 and the outer shaft 62 of the laminated shaft 6 rolled in the first step, and the thread-shaped indentation can be destroyed in the secondary rolling of the shaping wedge 4, and the destroyed thread-shaped indentation can form circumferential and radial limitation dents on the combination interface of the inner and outer shafts 61 and 62 so as to improve the circumferential and axial strength of the inner and outer shafts 61 and 62 at the same time.Embodiment 12

[0131] As shown in FIG. 5, on the basis of the embodiment 7, multiple pre-squeezing stripes 3 are disposed and the multiple pre-squeezing stripes 3 are paralleled and spaced apart.

[0132] In the above technical solution, the multiple pre-squeezing stripes 3 paralleled and spaced apart can form multiple uniformly-distributed helical grooves 63 on the laminated shaft 6, which increases a contact area and a number of the mechanical engagement points of the combination interface of the inner and outer shafts 61 and 62, so as to effectively increase a frictional force and a combination strength of the combination interface. In this way, the performances of the axial shear resistance and the circumferential twist resistance of the laminated shaft 6 can be better improved. Furthermore, the multiple paralleled and spaced-apart pre-squeezing stripes 3 can also make a pressure more uniformly distributed on the laminated shaft 6, reducing local stress concentration and improving the entire stability and durability of the laminated shaft 6.

[0133] Preferably, multiple pre-squeezing stripes 3 form a pre-squeezing stripe group with a width b1 less than or equal to a width b2 of the widest span of the shaping wedge 4.

[0134] In the above technical solution, it is guaranteed that, in the rolling process, the shaping wedge 4 can fully process the indentation generated by the pre-squeezing stripe 3 on the outer shaft 62 such that the indentation on the outer surface of the outer shaft 62 can be more effectively rolled flat. Furthermore, the indentation on the outer surface can also be more smoothly transferred to the combination interface of the inner and outer shafts 61 and 62 so as to form a combination interface having specific wave characteristics, helping to improve the entire quality and performance of the laminated shaft and making it more stable and more reliable in the use process.Embodiment 13

[0135] There is provided a cross wedge rolling method, which, based on the cross wedge rolling device mentioned in any one of the above embodiments 7 to 12, includes the following steps:

[0136] at step S100, at step S100, the inner and outer shafts 61 and 62 prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;

[0137] at step S200, after completion of the welding, the assembled laminated shaft 6 is sent into a heating furnace for heating;

[0138] at step S300, the heated laminated shaft 6 is sent into the cross wedge rolling device and positioned inside the positioning assembly 7;

[0139] at step S400, the rotation drive mechanism 82 drives the cross rolling rollers 12 to rotate to enable the laminated shaft 6 to sequentially run over the pre-squeezing stripe 3 and the shaping wedge 4; when the laminated shaft 6 runs over the pre-squeezing stripe 3, an indentation is generated on the outer surface of the outer shaft 62 while the indentation is transferred to the inner shaft 61; when the laminated shaft 6 runs over the shaping wedge 4, the indentation on the outer surface of the outer shaft 62 is rolled flat under the effect of the shaping wedge 4; at the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to the combination interface of the inner and outer shafts 61 and 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the inner and outer shafts 61 and 62 has wave characteristics;

[0140] at step S500, the formed laminated shaft 6 is taken out from the positioning assembly 7.

[0141] In the above cross wedge rolling process method, assembling is completed by interference fit and then welding is carried out, which ensures the inner shaft 61 and the outer shaft 62 are closely combined prior to rolling. The assembled laminated shaft 6 is sent into the heating furnace and heated to a proper rolling temperature, increasing the plasticity of the material. The heated laminated shaft 6 is sent into the cross wedge rolling device, and placed into the positioning assembly 7 between the two cross rolling rollers 12. When the rotation drive mechanism 82 drives the cross rolling rollers 12 to rotate, the cylindrical surface of the laminated shaft 6 firstly rolls over the pre-squeezing stripe 3 and is squeezed by the pre-squeezing stripe 3 to leave an indentation on an outer surface of the outer shaft 62 while transferring the indentation to the inner shaft 61, and next, the laminated shaft 6 continues rolling over the shaping wedge 4 and leaves the indentation on the outer surface of the outer shaft 62 rolled flat under the squeezing effect of the shaping wedge 4; meanwhile, the indentation on the outer surface is further transferred under the effect of the shaping wedge 4 to a combination interface of the inner shaft 61 and the outer shaft 62; the finally-rolled laminated shaft 6 has a smooth and flat outer surface, and the combination interface of the outer shaft 61 and the inner shaft 62 has wave characteristics. Finally, the formed laminated shaft 6 is taken down from the positioning assembly 7 and a new unformed laminated shaft 6 is placed into the positioning assembly 7 again to continue the processing of the next part. The above technical solution can not only realize rolling on the laminated shaft 6 under high temperature but also enable the combination interface of the outer and inner shafts 62 and 61 of the rolled laminated shaft 6 to have wavy mechanical engagement, making the formed laminated shaft 6 have the characteristics of axial shear resistance and circumferential twist resistance. Furthermore, the manufacturing process of the laminated shaft 6 can be completed by only one rolling process without requiring any additional process. Therefore, the entire processing efficiency will not be affected. Furthermore, the cross rolling rollers 12 can provide reliable support for the rolling arc surfaces 22, ensuring the structural strength and stability of the rolling arc surfaces 22 and hence ensuring the quality stability of the formed products. In addition, Furthermore, the cross rolling rollers 12 can rotate all the time along one direction without repeating operation, leading to higher processing efficiency.

Claims

1. A cross wedge rolling mechanism for rolling a laminated shaft, which comprises a drive mechanism and two paralleled and opposed cross rolling moulds; the drive mechanism is in transmission connection with at least one cross rolling mould and drives the cross rolling mould to move; a contact surface in contact with the laminated shaft is disposed on the cross rolling moulds, wherein a pre-squeezing stripe protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould; a shaping wedge protruding out of the contact surface is disposed on the contact surface of at least one cross rolling mould; an included angle α of an extending direction of the pre-squeezing stripe and a moving direction of the cross rolling mould is less than 45°; the pre-squeezing stripe is disposed in front of the shaping wedge such that the laminated shaft can sequentially run over the pre-squeezing stripe and the shaping wedge during moulding.

2. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein the drive mechanism is a linear drive mechanism, and the cross rolling moulds are plate-type moulds; the linear drive mechanism is connected with at least one plate-type mould such that the two plate-type moulds can translate toward each other; the contact surface is used to abut against a support surface of the laminated shaft.

3. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein the drive mechanism is a rotation drive mechanism, and the cross rolling moulds are cross rolling rollers which move in opposite directions; the rotation drive mechanism is in transmission connection with at least one cross rolling roller and drives the cross rolling roller to rotate; the contact surface is a peripheral rolling arc surface of the cross rolling rollers, and the pre-squeezing stripe extends along a peripheral direction of the rolling arc surface.

4. The cross wedge rolling mechanism for rolling a laminated shaft of claim 3, wherein at least one of the cross rolling rollers comprises a roller body and a cross rolling arc plate detachably mounted on a cylindrical surface of the roller body; the cross rolling arc plate partially wraps the roller body along a circumferential direction of the cross rolling roller and protrudes out of the cylindrical surface of the roller body; the rolling arc surface is disposed on the cross rolling arc plate.

5. The cross wedge rolling mechanism for rolling a laminated shaft of claim 4, wherein the radiuses of the two cross rolling rollers are R1 and R2 respectively, a distance between the two axes of the two cross rolling rollers is L, and an outer diameter of the laminated shaft is D1, and R1+R2+D1≤L≤H0+R1+R2+D1; when only one cross rolling roller comprises the cross rolling arc plate, the H0 is a height that the rolling arc surface in the cross rolling arc plate protrudes out of the cylindrical surface of the roller body; when each of two cross rolling rollers comprises the cross rolling arc plate, the H0 is a sum of the heights that the two rolling arc surfaces protrude out of the cylindrical surfaces of the corresponding roller bodies.

6. The cross wedge rolling mechanism for rolling a laminated shaft of claim 3, wherein distances of the two rolling arc surfaces from the axes of the corresponding cross rolling rollers are L1 and L2 respectively, and the distance between the two axes of the two cross rolling rollers is L, and the outer diameter of the laminated shaft is D1, and L1+L2+D1≤L;when the pre-squeezing stripe is disposed on the rolling arc surface of only one cross rolling roller, a height that the pre-squeezing stripe protrudes out of the corresponding rolling arc surface is H1, and H1+L1+L2+D1≥L;when the pre-squeezing stripe is disposed on the rolling arc surface of each of the two cross rolling rollers, the heights that the two pre-squeezing stripes protrude out of the corresponding rolling arc surfaces are H1 and H2, and H1+H2+L1+L2+D1≥L;when the shaping wedge is disposed on the rolling arc surface of only one cross rolling roller, the height that the shaping wedge protrudes out of the corresponding rolling arc surface is H3, and H3+L1+L2+D1≥L;when the shaping wedge is disposed on the rolling arc surface of each of the two cross rolling rollers, the heights that the two shaping wedges protrude out of the corresponding rolling arc surfaces are H3 and H4, and H3+H4+L1+L2+D1≥L.

7. The cross wedge rolling mechanism for rolling a laminated shaft of claim 3, wherein the pre-squeezing stripe extends helically along a peripheral direction of the cross rolling roller, and a helical angle of the pre-squeezing stripe is β, where β=90°−α and 80°β90°.

8. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein the height that the shaping wedge protrudes out of the corresponding contact surface is greater than the height that the pre-squeezing stripe protrudes out of the corresponding contact surface.

9. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein 0°α10°.

10. The cross wedge rolling mechanism for rolling a laminated shaft of claim 9, wherein the pre-squeezing stripes on the two cross rolling moulds are mutually matched so that helical grooves formed by the two pre-squeezing stripes on the laminated shaft are overlapped or connected head to tail.

11. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein multiple pre-squeezing stripes are disposed, and the multiple pre-squeezing stripes are paralleled and spaced apart.

12. The cross wedge rolling mechanism for rolling a laminated shaft of claim 11, wherein multiple pre-squeezing stripes form a pre-squeezing stripe group with a width less than or equal to a width of the widest span of the shaping wedge.

13. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein a front end of the pre-squeezing stripe is provided with a transitional stripe with its height increasing from front to back.

14. The cross wedge rolling mechanism for rolling a laminated shaft of claim 1, wherein the shaping wedge comprises a shaping front portion and a shaping rear portion at a rear side of the shaping front portion; a width of the shaping front portion increases from an end away from the shaping rear portion to an end close to the shaping rear portion; a front side of the shaping front portion is provided with a transitional portion with a height increasing from an end away from the shaping front portion to an end close to the shaping front portion.

15. A cross wedge rolling device for rolling the laminated shaft, wherein the device comprises a fixing frame and the cross wedge rolling mechanism of claim 2; one of the two plate-type moulds is fixed to the fixing frame and the other is slidably connected with the fixing frame; the two plate-type moulds are disposed up and down, and the linear drive mechanism is mounted on the fixing frame.

16. A cross wedge rolling device for rolling the laminated shaft, wherein the device comprises a machine frame, a positioning assembly and the cross wedge rolling mechanism of claim 3; the two cross rolling rollers are rotatably connected to the machine frame, the positioning assembly and the rotation drive mechanism are mounted on the machine frame, and the positioning assembly is disposed between the two cross rolling rollers.

17. The cross wedge rolling device for rolling the laminated shaft of claim 16, wherein the positioning assembly comprises a first clamping plate and a second clamping plate extending along an axial direction of the cross rolling rollers; the first clamping plate and the second clamping plate are disposed in a spacing between the two cross rolling rollers and mounted on the machine frame; an avoiding gap is reserved between the first clamping plate and the cross rolling rollers, and an avoiding gap is reserved between the second clamping plate and the cross rolling rollers; a positioning groove extending along an axial direction of the cross rolling rollers is disposed between the first clamping plate and the second clamping plate; at least one end of the positioning groove along the axial direction of the cross rolling rollers is disposed as opening.

18. A cross wedge rolling method, wherein the method comprises the following steps based on the cross wedge rolling device of claim 15:at step S100, the inner and outer shafts of the laminated shaft prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;at step S200, after completion of the welding, the assembled laminated shaft is sent into a heating furnace for heating;at step S300, the heated laminated shaft is sent into the cross wedge rolling device and the two plate-type moulds tightly clamp the laminated shaft;at step S400, the two plate-type moulds are moved toward each other to enable the laminated shaft to sequentially run over the pre-squeezing stripe and the shaping wedge; when the laminated shaft runs over the pre-squeezing stripe, an indentation is generated on the outer surface of the outer shaft while the indentation is transferred to the inner shaft; when the laminated shaft runs over the shaping wedge, the indentation on the outer surface of the outer shaft is rolled flat under the effect of the shaping wedge; at the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge to the combination interface of the inner and outer shafts; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the inner and outer shafts has wave characteristics;at step S500, the formed laminated shaft is taken out.

19. A cross wedge rolling method, wherein the method comprises the following steps based on the cross wedge rolling device of claim 17:at step S100, the inner and outer shaft prior to rolling are assembled by a press machine through interference fit and then welding is performed at ends;at step S200, after completion of the welding, the assembled laminated shaft is sent into a heating furnace for heating;at step S300, the heated laminated shaft is sent into the cross wedge rolling device and positioned inside the positioning assembly;at step S400, the rotation drive mechanism drives the cross rolling rollers to rotate to enable the laminated shaft to sequentially run over the pre-squeezing stripe and the shaping wedge; when the laminated shaft runs over the pre-squeezing stripe, an indentation is generated on the outer surface of the outer shaft while the indentation is transferred to the inner shaft; when the laminated shaft runs over the shaping wedge, the indentation on the outer surface of the outer shaft is rolled flat under the squeezing effect of the shaping wedge; at the same time, the indentation on the outer surface is further transferred under the effect of the shaping wedge to the combination interface of the inner and outer shafts; the finally-rolled laminated shaft has a smooth and flat outer surface, and the combination interface of the inner and outer shafts has wave characteristics;at step S500, the formed laminated shaft is taken out from the positioning assembly.

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