阅读说明：本技术 一种铁道车辆车轴的楔横轧组合模具及其成形方法 (Cross wedge rolling combined die of railway vehicle axle and forming method thereof ) 是由 杨翠苹 王宝雨 李树林 徐俊生 刘晋平 郑振华 周靖 于 2021-07-26 设计创作，主要内容包括：本发明属于金属塑性成形技术领域,特别涉及一种铁道车辆车轴的楔横轧组合模具及其成形方法。所述组合模具包括轴身通用模具,用于轧制成形车轴的轴身部分,不同车轴能够共用该轴身通用模具；台阶成形专用模具,根据不同车轴台阶形状及尺寸确定模具孔型,用于将车轴的台阶形状和两侧其余部分轧制成形,所述轴身通用模具和台阶成形专用模具组合,将整个铁道车辆车轴轧制成形。该方法大幅度的减小了楔横轧模具和轧机的尺寸及重量,降低了轧机载荷,显著地降低模具成本。适用于实现楔横轧铁道车辆车轴的成形问题。(The invention belongs to the technical field of metal plastic forming, and particularly relates to a cross wedge rolling combined die of a railway vehicle axle and a forming method thereof. The combined die comprises a shaft body universal die for roll forming of a shaft body part of the axle, and different axles can share the shaft body universal die; the special step forming die determines the die hole pattern according to the step shapes and sizes of different axles and is used for roll forming the step shapes and the other parts on two sides of the axles, and the universal axle body die and the special step forming die are combined to roll form the whole railway vehicle axle. The method greatly reduces the size and the weight of the cross wedge rolling die and the rolling mill, reduces the load of the rolling mill, and obviously reduces the die cost. The method is suitable for realizing the forming problem of the wedge cross rolling railway vehicle axle.)

1. A cross wedge rolling composite mold for a railway vehicle axle, the mold comprising:

the universal shaft body die is used for roll forming the shaft body part of the axle, and different axles can share the universal shaft body die;

the special step forming die determines a die hole pattern according to the shapes and sizes of different axle steps and is used for rolling and forming the step shape and other parts on two sides of the axle;

the axle body general die and the step forming special die are combined to roll and form the whole railway vehicle axle.

2. The cross wedge rolling combined die for the railway vehicle axle according to claim 1, wherein the axle body general die does not comprise an axle step pass, and axle bodies of different diameters can be formed by adjusting the center distance of the axle body general die for different axles.

3. The cross-wedge rolling composite mold for railway vehicle axle shafts as claimed in claim 2, wherein the mold wedge of the axle body general mold is composed of a forming section and a finishing section with the same top surface height H, the axle body general mold forming section rolls the axle shaft from an original diameter D0 to an axle body diameter D1 through the mold wedge, the widening length M1 of the wedge is less than L1, wherein L1 is the axle shaft length.

4. The cross wedge rolling combined die for the railway vehicle axle according to claim 2, wherein the inclination angle of the finishing section of the axle body general die is the inclination angle of the inclined step of the formed rolled piece and is equal to the forming angle α 1 of the forming section.

5. The cross wedge rolling combined die for the axle of the railway vehicle as claimed in claim 1, wherein the special step forming die comprises all step passes of the axle, and the remaining axle body, the wheel seat, the axle diameter and the steps therebetween are roll-formed to ensure the axial dimensional accuracy of the axle forming.

6. The cross wedge rolling combination die for railway vehicle axles as claimed in claim 5, wherein the die wedge top height and axial position variation of the step forming dedicated die are matched with all step passes included, and the forming angle and spread angle of the remaining axle body forming part on the step forming dedicated die are equal to the forming angle α 1 and spread angle β 1 of the axle body general die.

7. The cross wedge rolling combined die for the axle of the railway vehicle as claimed in claim 1, wherein the axle body general die and the step forming special die are in a W x L standard block splicing mode, and die blocks are arranged along the forming wedge;

and a positioning key is arranged in the middle of the die block of the special die for step forming and is used for offsetting the axial force of a rolled piece on the die in the rolling forming process.

8. The cross wedge rolling segmented mold for railway vehicle axles as claimed in claim 1, wherein the forming angle α 1 of the shaft body portion of the mold is 30 ° to 45 ° and the spread angle β 1 is 6.0 ° to 8.5 °; the forming angle alpha 2 of the outer step shaft section of the special die for forming the step is 27-42 degrees, and the spread angle beta 2 is 8-11.5 degrees.

9. The cross wedge rolling combined die for the axle of the railway vehicle as claimed in claim 1, wherein the general axle body die and the special step forming die can be installed in a parallel unit of two cross wedge rolling mills driven by motors independently or a series unit of cross wedge rolling mills driven by a motor in a centralized manner.

10. A method of forming a cross wedge rolling combined mold for a railway vehicle axle according to any one of claims 1 to 9, comprising the steps of:

s1, adjusting the center distance of the universal axle body die according to the diameter of the axle body of the rolled railway vehicle axle to ensure that the distance between the upper die and the lower die is correspondingly equal to the diameter of the axle body of the axle;

s2, heating an original rolled piece to a rolling temperature, feeding the original rolled piece between general shaft body moulds, wherein the original rolled piece is driven by the general shaft body moulds to rotate, most of the shaft body of an axle is rolled to form an intermediate rolled piece, two sides of the intermediate rolled piece are in an inclined step shape with an inclination angle equal to a mould forming angle, the rolling length M1 is less than L1, and L1 is the length of the axle body of the axle;

s3, the intermediate rolled piece is conveyed between the special step forming dies, the intermediate rolled piece is driven by the special step forming dies to rotate, the forming wedge is unfolded from the inclined step of the rolled piece, the step of the axle and the rest parts at two sides are rolled and formed, the rolling length is 2 xM 2 and is equal to (L0-M1), wherein L0 is the total length of the axle, and after two times of rolling, the whole axle of the railway vehicle is rolled and formed.

Technical Field

The invention belongs to the technical field of metal plastic forming, and particularly relates to a cross wedge rolling combined die of a railway vehicle axle and a forming method thereof.

Background

The axle is a key part of the railway vehicle, and with the increasing scale of railway network construction, the market demand of the axle is large. Cross wedge rolling is a green advanced near-net forming technology and is widely applied to forming shaft parts. As a large batch of shaft parts, the axle of the railway vehicle is produced by adopting a cross wedge rolling near-net forming technology, and compared with the original forging, the axle has the advantages of high efficiency, material saving, environmental friendliness and the like. But the axle of the railway vehicle is an ultra-large shaft part with the diameter larger than phi 190mm and the length larger than 2200mm, a pair of dies and a single wedge are adopted for one-step forming, the diameter of the dies needs to be more than phi 3400mm, and the equipment is huge; and a pair of dies and a plurality of wedges are adopted for one-time forming, although the diameter of the die is reduced, the load of the device is increased by multiple times of that of a single wedge, and the difficulty of manufacturing and debugging the die is very high. Therefore, the equipment for forming the axle of the railway vehicle by using a pair of molds is huge and difficult to implement. In view of the above, there is a need to provide a solution to overcome or at least mitigate at least one of the above-mentioned drawbacks of the prior art.

Disclosure of Invention

In order to solve the problems, the invention provides a cross wedge rolling combined die of a railway vehicle axle and a forming method thereof, wherein the forming method is characterized in that the axle bodies of axles with different diameters are formed on a first pair of cross wedge rolling axle body general dies by adjusting the center distance of the dies; on the special die for forming the axle step of the second pair of cross wedge rolling, the die with different axle step hole patterns is adopted to roll and form the axle step and the rest parts at two sides, so that the whole axle is rolled and formed by combining the two pairs of dies. The method greatly reduces the size and the weight of the cross wedge rolling die and the rolling mill, reduces the load of the rolling mill, and obviously reduces the die cost. The method is suitable for realizing the forming problem of the wedge cross rolling railway vehicle axle.

The invention is realized by the following technical scheme:

the invention provides a cross wedge rolling combined die of a railway vehicle axle, which comprises:

the universal axle body die is used for roll forming the axle body part of the axle, and different axles can share the die;

the special step forming die determines a die hole pattern according to the shapes and sizes of different axle steps and is used for rolling and forming the step shape and other parts on two sides of the axle;

the universal die for the cross wedge rolling axle body and the special die for step forming are combined to roll and form the whole railway vehicle axle.

Furthermore, the universal axle body die does not comprise a hole pattern, and axle bodies of different diameters can be formed by adjusting the center distance of the die for different axles.

Further, the die wedge of the axle body general die consists of a forming section and a finishing section with the same top surface height H, the axle body general die forming section rolls the axle from the original diameter D0 to the axle body diameter D1 through the die wedge, the widening length M1 of the wedge is < L1, wherein L1 is the axle body length.

Further, the inclination angle of the finishing section of the universal shaft body die is the inclination angle of an inclined step of the formed rolled piece and is equal to the forming angle alpha 1 of the forming section.

Furthermore, the special step forming die comprises all step pass of the axle, and the residual axle body, the wheel seat, the axle diameter and steps among the axle body, the wheel seat and the axle diameter are rolled and formed, so that the axial size precision of axle forming is ensured.

Furthermore, the height and the axial position change of the top surface of the die wedge of the special die for step forming are matched with all the step hole patterns, and the forming angle and the spread angle of the residual shaft body forming part on the special die for step forming are equal to the forming angle alpha 1 and the spread angle beta 1 of the universal die for shaft body.

Furthermore, the general shaft body mould and the special step forming mould adopt a W multiplied by L standard block splicing mode, and the mould blocks are arranged along the forming wedge.

Furthermore, a positioning key is arranged in the middle of a die block of the special die for step forming and used for offsetting the axial force of a rolled piece on the die in the rolling forming process.

Further, the forming angle alpha 1 of the shaft body part of the die is 30-45 degrees, and the spread angle beta 1 is 6.0-8.5 degrees. The forming alpha 2 angle of the outer step shaft section of the special die for forming the step is 27-42 degrees, and the spread angle beta 2 angle is 8-11.5 degrees.

Preferably, the forming angle alpha 1 of the shaft body part of the die is 40 degrees, and the spread angle beta 1 is 7.5 degrees. The forming angle alpha 2 of the outer step shaft section of the special die for forming the step is 32 degrees, and the spread angle beta 2 is 9.5 degrees.

Furthermore, the general shaft body mould and the special step forming mould can be arranged on a parallel unit of two cross wedge rolling mills driven by motors independently or a series unit of cross wedge rolling mills driven by a motor in a centralized way.

Another object of the present invention is to provide a method of forming a cross wedge rolling combined mold for a railway vehicle axle, the method comprising the steps of:

and S1, adjusting the center distance of the universal axle body die according to the diameter of the axle body of the rolled railway vehicle axle, so that the distance between the upper die and the lower die is correspondingly equal to the diameter of the axle body of the axle.

S2, heating an original rolled piece to a rolling temperature, sending the original rolled piece into a space between a first pair of cross wedge rolling dies, namely a shaft body universal die, wherein the rolled piece is driven by the die to rotate, most of the shaft body of an axle is rolled and formed, two sides of the rolled piece are in an inclined step shape with an inclination angle equal to a forming angle of the die, the rolling length M1 is less than L1, and L1 is the length of the axle body of the axle;

s3, conveying the rolled piece into a second auxiliary wedge transverse rolling die, namely a die special for step forming, wherein the rolled piece is driven by the die to rotate, forming wedges are unfolded from the inclined steps of the rolled piece, the steps and the rest parts on two sides of the axle are rolled and formed, the rolling length is 2 multiplied by M2 and is equal to (L0-M1), and L0 is the total length of the axle;

after the two pairs of dies are rolled twice, the whole axle of the railway vehicle is rolled and formed.

The invention has the beneficial effects that:

the technical scheme of the invention is suitable for realizing the cross wedge rolling forming of the axle of the railway vehicle, and the method for forming the axle of the railway vehicle by adopting the cross wedge rolling combined die can greatly reduce the size and the weight of the cross wedge rolling die and the rolling mill, reduce the load of the rolling mill and obviously reduce the die cost.

Drawings

Fig. 1 is a schematic view of a railway vehicle axle structure according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of rolled pieces at different stages in the embodiment of the invention, which comprises the following steps: the original rolled piece (a), the first secondary die-formed rolled piece (b) and the second secondary die-formed rolled piece (c).

Fig. 3 is a schematic view (b) of the unfolding structure of the general axle body die (a) and the step forming die in the embodiment of the invention.

Fig. 4 is a schematic sectional view taken along line a-a in fig. 3.

Fig. 5 is a schematic cross-sectional view of B-B in fig. 3.

FIG. 6 is a three-dimensional schematic view of a rolled product and a mold, including: a general shaft body mould (a) and a special step forming mould (b).

Fig. 7 is a schematic view of a mold block structure in the prior art.

FIG. 8 is a schematic view of a split die cross wedge mill train comprising: a parallel unit (a) and a series unit (b).

FIG. 9 is a flowchart of a method of forming a cross wedge rolling segmented mold for a railway vehicle axle in an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

On the contrary, the invention is intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The invention relates to a method for forming a railway vehicle axle based on a cross wedge rolling combined die, which solves the problem of forming the railway vehicle axle shown in figure 1 and realizes the accurate forming of the cross wedge rolling railway vehicle axle.

Example 1

The present embodiment provides a cross wedge rolling combined mold for a railway vehicle axle, as shown in fig. 3 to 6, the mold comprising: the first pair is a universal die for the cross wedge rolling shaft body and is used for rolling and forming part of the shaft body of the axle, and different axles can share the die; the special die for forming the steps of the second pair of cross wedge rolling axles is used for rolling and forming the step shape and the rest parts at two sides of the axle to ensure the axial dimension precision of the axle. The mould blocks are distributed along the forming wedge, and the second pair of moulds adopts a middle positioning key to offset the axial force. The forming method is characterized in that the forming of axle bodies of axles with different diameters is realized on a first auxiliary cross wedge rolling axle body universal mould by adjusting the center distance of the mould; on the special die for forming the axle step of the second pair of cross wedge rolling, the die with different axle step hole patterns is adopted to roll and form the axle step and the rest parts at two sides, so that the whole axle is rolled and formed by combining the two pairs of dies.

Specifically, the axle body general die is used for roll forming the axle body part of the axle, and different axles share the die; the special step forming die determines a die hole pattern according to the shapes and sizes of different axle steps and is used for rolling and forming the step shape and other parts on two sides of the axle; the universal wedge cross rolling axle body forming die and the special step forming die are combined to roll and form the whole railway vehicle axle.

The axle body general die does not comprise an axle step hole pattern, the die wedge consists of a forming section and a finishing section with the same top surface height H, the diameter D1 of the axle body is different from the original diameter D0 for different axles, the diameter difference of (D0-D1) is also different, the top surface height H of the axle body general die comprehensively considers the wedge height requirements of different axles, the wedge top surface height H is determined to be MAX ((D0-D1)/2) + delta according to the maximum value of the diameter difference and the base circle gap, delta is the base circle gap, and delta is 3 mm. When different axles are formed, axles with different diameters are formed by adjusting the center distance O of the die₁O₂The method of (1) is realized, the effective wedge height is the diameter difference (D0-D1)/2 of the axle, and the corresponding base circle gap is (H- (D0-D1)/2); the axle body general die forming section rolls the axle from an original diameter D0 to an axle body diameter D1 through a die wedge, and the widening length M1 of the wedge<L1, wherein L1 is the axle body length. The inclination angle of the finishing section of the shaft body universal die is the inclination angle of an inclined step of a formed rolled piece and is equal to the forming angle alpha 1 of the forming section.

The step forming special die comprises a pass of all steps of the axle, the height and axial position change of the top surface of a wedge of the die are matched with the pass, and the rest axle body, a wheel seat, the axle diameter and the steps among the axle body, the wheel seat and the axle diameter are rolled and formed, so that the axial size precision of axle forming is ensured; the forming angle and the spread angle of the forming part of the residual shaft body on the special step forming die are equal to the forming angle alpha 1 and the spread angle beta 1 of the general shaft body die; the general shaft body mould and the special step forming mould adopt a W multiplied by L standard block splicing mode, and mould blocks are arranged along a forming wedge; and a positioning key is arranged in the middle of the die block of the special die for step forming and is used for offsetting the axial force of a rolled piece on the die in the rolling forming process.

The forming angle alpha 1 of the shaft body part of the die is 30-45 degrees, and the spread angle beta 1 is 6.0-8.5 degrees. The forming alpha 2 angle of the outer step shaft section of the special die for forming the step is 27-42 degrees, and the spread angle beta 2 angle is 8-11.5 degrees. Preferably, the shaft general mold forming angle alpha 1 is 40 degrees, and the spread angle beta 1 is 7.5 degrees. The forming angle alpha 2 of the outer step shaft section of the special die for forming the step is 32 degrees, and the spread angle beta 2 is 9.5 degrees.

The general shaft body mold and the special step forming mold may be installed in two parallel motor driven wedge rolling mill sets or one serial motor driven wedge rolling mill set, as shown in fig. 7.

Another object of the present invention is to provide a method of forming a cross wedge rolling combined mold for a railway vehicle axle, as shown in fig. 9, the method comprising the steps of:

s1, adjusting the center distance O of the universal die of the axle body according to the diameter of the axle body of the rolled railway vehicle axle₁O₂The distance between the upper die and the lower die is correspondingly equal to the diameter of the axle body of the axle.

S2, heating an original rolled piece (shown as (a) in FIG. 2) to a rolling temperature, sending the original rolled piece into a space between a first secondary wedge transverse rolling die and a general shaft body die, wherein the rolled piece is driven by the die to rotate, most of the shaft body of an axle is rolled and formed, two sides of the rolled piece are in an inclined step shape (shown as (b) in FIG. 2) with an inclination angle equal to a forming angle of the die, the rolling length is M1< L1, and L1 is the length of the shaft body of the axle;

s3, conveying the rolled piece into a second auxiliary wedge transverse rolling die, namely a die special for step forming, wherein the rolled piece is driven by the die to rotate, forming wedges are unfolded from the inclined steps of the rolled piece, and the steps and the rest parts of two sides of the axle are rolled and formed (as shown in (c) in FIG. 2), wherein the rolling length is 2 xM 2 and is equal to (L0-M1), and L0 is the total length of the axle; after the two pairs of dies are rolled twice, the whole axle of the railway vehicle is rolled and formed.

The wedge cross rolling combined die of the railway vehicle axle and the forming method thereof have the following realization principles:

the main structural form of the railway vehicle axle is shown in fig. 1, and the axle forms of different types have basically the same structure, but have different diameters and different step sizes. The axle body part of the axle which is mainly formed when the first secondary die rolls is determined according to the structural characteristics that the axle has a longer axle body, and the die only rolls and forms most of the axle body without determining the axial dimension of the axle body in order to ensure the axial dimension precision of the rolled axle, namely the rolling length of the part M1 is less than L1. The single diameter of the axle body corresponds to the structural characteristics of a simple mould, a single wedge and no step, the mould structure is universal for axles of any types, and the difference of the diameters of the axle bodies of different axles can be realized by changing the center distance of the mould. Therefore, the first auxiliary die is used as a universal die, the number of the dies can be obviously reduced, the processing and manufacturing cost is saved, the time for installing and debugging the dies is reduced, and the advantages are prominent. The second set of dies rolls the remaining shaft and the other portions of the two sides. The diameter sizes and the step shapes of axles of different models are different, and the die hole pattern needs to be determined according to the rolled axle, so that the part is a special die. All the axle steps are concentrated in a special die, and are formed in one step in the restriction of the die hole pattern, so that the dimensional accuracy of the axle can be effectively ensured. The prior art die block configuration (as shown in fig. 6) can be optimized in view of the fact that the forming wedge, which is the primary role of the die during the rolling stock forming process, does not function, and the dies outside the forming wedge and inside the second set of die forming wedges (the formed shaft body portion). The use of standard mold blocks along the forming wedge, as shown in fig. 3, significantly reduces mold weight and cost. To the neutral gear that the vice mould piece intermediate position of second formed, increased the axial force that the rolling piece produced the mould among the positioning key offset rolling process, the positioning key plays the effect of axial positioning benchmark simultaneously, makes things convenient for the die holding.

In the present embodiment, according to the cross wedge rolling combined die for a railway vehicle axle and the forming method thereof, the original rolled piece diameter D0 is Φ 228mm, and the size of the formed axle is: the total length L0 is 2201mm, the shaft body length L1 is 1150mm, the diameter D1 is phi 192mm, the wheel seat length L2 is 200.5mm, the shaft diameter length L3 is 179.5mm, and the diameter D2 is phi 162 mm. The shaft body part of the die adopts a preferred forming angle alpha 1 and an angle of 40 degrees, and a preferred spreading angle beta 1 and an angle of 7.5 degrees. The forming alpha 2 angle of the outer step shaft section of the special die for forming the step is 32 degrees, and the spread angle beta 2 angle is 9.5 degrees. The rolling diameter D1 of the universal die for the shaft body is phi 192mm, the rolling length M1 is 990mm, the rolling length 2 multiplied by M2 of the special die for step forming is 2 multiplied by 525.5mm, and the special die for step forming comprises the residual shaft body, the wheel seat, the shaft diameter and steps among the residual shaft body, the wheel seat and the shaft diameter.

Example 2

The cross wedge rolling combined mold for a railway vehicle axle and the forming method thereof of the present embodiment are basically the same as those of embodiment 1, except that:

in the present embodiment, according to the cross wedge rolling combined die for a railway vehicle axle and the forming method thereof, the original rolled piece diameter D0 is Φ 212mm, and the size of the formed axle is: the total length L0 is 2161mm, the shaft length L1 is 1155mm, the diameter D1 is phi 182mm, the wheel seat length L2 is 202mm, the shaft diameter length L3 is 187mm, and the diameter D2 is phi 142 mm. The general mould of axle body shares with embodiment 1, and the shaping alpha 2 angle of the outer step axle section of the special mould for step shaping is 27 degrees, and the spread angle beta 2 angle is 8 degrees. The rolling diameter D1 of the universal die for the shaft body is phi 182mm, the rolling length M1 is 990mm, the rolling length 2 multiplied by M2 of the special die for step forming is 2 multiplied by 585.5mm, and the special die for step forming comprises the residual shaft body, the wheel seat, the shaft diameter and steps among the residual shaft body, the wheel seat and the shaft diameter.

Example 3

The cross wedge rolling combined mold for a railway vehicle axle and the forming method thereof of the present embodiment are basically the same as those of embodiment 1, except that:

in the present embodiment, according to the cross wedge rolling combined die for a railway vehicle axle and the forming method thereof, the original rolled piece diameter D0 is Φ 248mm, and the size of the formed axle is: the total length L0 is 2229mm, the shaft body length L1 is 1145mm, the diameter D1 is phi 208mm, the wheel seat length L2 is 196mm, the shaft diameter length L3 is 186mm, and the diameter D2 is phi 172 mm. The axle body universal mold was used in common with example 1. The forming alpha 2 angle of the outer step shaft section of the special die for forming the step is 42 degrees, and the spread angle beta 2 angle is 11.5 degrees. The rolling diameter D1 of the universal die for the shaft body is phi 208mm, the rolling length M1 is 990mm, the rolling length 2 multiplied by M2 of the special die for step forming is 2 multiplied by 542mm, and the special die for step forming comprises the residual shaft body, the wheel seat, the shaft diameter and steps among the residual shaft body, the wheel seat and the shaft diameter.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.