CN114798718A

CN114798718A - Inclined type precise wedge cross rolling forming device

Info

Publication number: CN114798718A
Application number: CN202210236150.7A
Authority: CN
Inventors: 王宝雨; 王佳鹏; 刘晋平
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2022-07-29
Anticipated expiration: 2042-03-11
Also published as: CN114798718B

Abstract

The invention relates to the technical field of metal plastic forming equipment, and provides an inclined type precise cross wedge rolling forming device, wherein rack units are symmetrically arranged on a base; the guide plate feeding units are symmetrically arranged above the base; the left and right moulds are coaxially fixed by a left shaft system and a right shaft system respectively; the driving unit is coaxially arranged on the shafting unit and drives the die to rotate; the roll spacing adjusting unit is arranged above the rolling mill in a penetrating way, and the size of the distance between the dies is adjusted by controlling the opening and closing degree of the rack; the synchronous units are symmetrically arranged below the rolling mill to ensure that the two racks are synchronously opened and closed; the lifting and inclining unit provides the inclination angle required by the rolling mill by controlling the lifting height. The blanks reach the designated position through the guide plate feeding unit, the roller spacing is adjusted through the roller spacing adjusting unit, and the driving unit provides rolling power to roll the blanks in a wedge-shaped mode into products. The invention has the advantages of high rolling precision, convenient die replacement, high automation degree and the like, can realize quick feeding and discharging by utilizing the self weight of a rolled piece, obviously improves the production efficiency and has wide application prospect.

Description

Inclined type precise wedge cross rolling forming device

Technical Field

The invention relates to the technical field of metal plastic forming equipment, in particular to a tilting type precise wedge cross rolling forming device.

Background

Cross wedge rolling is known to be an important component of today's advanced manufacturing technology as an efficient metal plastic forming process. The cross wedge rolling is widely applied to the production of shaft part blanks of automobiles, train axles, internal combustion engines and the like, and has been widely adopted in the market at present due to the advantages of high production efficiency, metal material saving, low production cost and the like.

The traditional cross wedge rolling mill discharging mode mostly adopts cylinder pushing, electric pushing cylinder pushing and the like, and rolled pieces formed by cross wedge rolling can fall out under the action of external force. If when the forming temperature is higher, the rolled piece still keeps higher temperature after forming, leads to thrust unit operational environment abominable, and needs a set of independent drive arrangement for the ejection of compact provides power, and is with high costs, operational environment abominable, higher to equipment requirement, is difficult to improve production efficiency, consequently urgently needs a kind of wedge cross rolling mill that can satisfy quick ejection of compact, production efficiency is high.

Disclosure of Invention

The invention aims to overcome at least the defects of slow discharging efficiency and high cost of the existing cross wedge rolling mill, and provides an inclined precise cross wedge rolling forming device.

The invention adopts the following technical scheme:

an inclined precise wedge cross rolling forming device comprises a rack unit, a shafting unit, a roller spacing adjusting unit, a guide plate feeding unit, a synchronizing unit, a driving unit, a base and an inclined unit;

the rack unit comprises a left rack and a right rack, is used for installing the shafting unit, the roller spacing adjusting unit and the synchronizing unit and bears rolling force; the left frame and the right frame can rotate around the frame rotating shaft;

the shafting unit is used for installing a roller, a cross wedge rolling die and the driving unit;

the roller spacing adjusting unit is used for driving the rollers to linearly move along the radial direction of the blank so as to adjust the roller spacing;

the guide plate feeding unit is used for feeding the blank into the roller to prevent the blank from swinging in the rolling process;

the synchronization unit is used for synchronously and reversely centering and opening the left rack and the right rack;

the driving unit is used for driving the shafting unit to drive the roller to rotate around the axis and provide rolling torque;

the rack unit is mounted on the base;

and the hoisting and inclining unit is used for hoisting the base so as to provide the inclination angle required by the device.

In any of the above possible implementation manners, an implementation manner is further provided, in which the left rack and the right rack are both bearing racks, and both the left rack and the right rack are processed with corresponding grooves for installing other units; the upper parts of the left frame and the right frame are respectively provided with a roller spacing adjusting unit revolute pair mounting hole, the middle parts of the left frame and the right frame are respectively provided with a shafting unit mounting groove, and the lower parts of the left frame and the right frame are respectively provided with a rotating shaft mounting hole; the left rack and the right rack are installed on the base through rack rotating shafts. The frame can rotate around the frame rotating shaft.

In any of the above possible implementations, there is further provided an implementation in which the synchronization unit includes two convex circular blocks and two concave circular slots; when the convex round block and the concave round groove are meshed and rotate, the left frame and the right frame are driven to synchronously open and close around the rotating shaft of the frame in a constant speed and reverse direction (through bolts).

In any of the above possible implementation manners, there is further provided an implementation manner, wherein the convex circular block engagement participating part is a convex semicircle, the concave circular groove engagement participating part is a concave semicircle, and the outer side of the concave semicircle is connected with the straight section; the convex round block and the concave round groove are matched tightly all the time in the meshing rotation process, the gap is extremely small, the center distance between the convex round block and the concave round groove is kept unchanged all the time, and therefore the center distance is unchanged in the rotation process of the left frame rotating shaft and the right frame rotating shaft. The problems of large meshing clearance and low rolling precision of the traditional gear are avoided; the concave-convex circle synchronous units are tightly matched and almost seamless, and the rolling precision can be improved from 0.5mm-1mm to 0.05mm-0.2 mm.

In any of the above possible implementation manners, there is further provided an implementation manner, where the shafting unit includes a left shafting and a right shafting; the left shafting and the right shafting both comprise a main shaft, a feeding end bearing seat, a discharging end bearing seat, an adjusting washer and a pre-tightening spring;

a cross wedge rolling die is arranged on the main shaft; the adjusting washers are coaxially arranged on two sides of the cross wedge rolling die; the main shaft is supported by the feeding end bearing seat and the discharging end bearing seat together; the feeding end bearing block and the discharging end bearing block are fixedly arranged in a shaft system mounting groove in the middle of the rack through bolts; and a pre-tightening spring is arranged between the bearing seats at the discharge ends of the left shaft system and the right shaft system, and the axis of the pre-tightening spring is vertical to the axis of the blank. The axial direction centering of the left and right cross wedge rolling dies can be ensured by processing adjusting washers with different thicknesses.

In any of the above possible implementations, there is further provided an implementation that the pre-tightening pressure F1 provided by the pre-tightening spring satisfies 0.1F<F1<0.3F, wherein F is the maximum rolling force which can be provided by the rolling mill. For rolling of middle and small shaft parts of phi 10-phi 70 and the like, the pre-tightening force F provided by the pre-tightening spring is set ₁ The rolling runout can be controlled to be 0.02-0.05 mm.

Any one of the possible implementations described above, further providing an implementation in which the roller gap adjustment unit includes a pull rod, a cylindrical washer, a lock nut, a dial, a pressure sensor;

the cylindrical gaskets are respectively arranged in the corresponding roller spacing adjusting unit grooves at the upper parts of the left frame and the right frame; one end of the pull rod is provided with a key groove to ensure that the pull rod and the rack do not rotate relatively; the locking nut is arranged at the tail part of the pull rod positioned at the outer side of the right rack, so that the left rack and the right rack can be ensured not to be opened and jumped in the rolling process by screwing the locking nut; the dial is arranged on the locking nut, and the accurate adjustment of the roller distance is realized by rotating to a corresponding scale; the pressure sensor is arranged between the cylindrical gasket and the right rack, and feeds back the instantaneous rolling force in real time by measuring the extrusion force applied in the rolling process.

Any of the possible implementations described above further provides an implementation in which the relative rotation angle β satisfies 0 ≦ β ≦ 12.

Any one of the above possible implementations further provides an implementation, in which the guide plate feeding unit includes a feeding rack, a guide plate, and a discharging rack; the feeding frame, the guide plate and the discharging frame are fixedly arranged on the base through bolts; the feeding frame is provided with a material guide rail, so that the blank can smoothly enter an accurate position corresponding to the cross wedge rolling die.

In any of the possible implementations described above, there is further provided an implementation in which the lifting and tilting unit is mounted below a rolling mill base, the base being provided with a corresponding tilt angle α by the lifting unit, α satisfying 15 ° α ≦ 35 °.

Any one of the above possible implementation manners further provides an implementation manner that the blank is a shaft part with a diameter of 10-70 mm and is used for cold precision cross wedge rolling or hot precision cross wedge rolling; the cold rolling temperature is room temperature, and the hot rolling temperature is 700-1200 ℃.

The device can meet the production efficiency of forming 15-25 pieces per minute.

The invention has the beneficial effects that:

1. the rolling piece can slide out of the rolling mill along the rail by using the self weight of the rolling piece at the moment that the rolling piece is separated from the die after the cross wedge rolling forming is finished, the discharging is rapid, an additional power device is not needed, the cost is low, and the production efficiency is high.

2. The bearing type frame is adopted, the left shafting and the right shafting which are provided with the integral type die and the roll spacing adjusting unit are directly embedded and installed in the frame, the force transmission path is short, the whole rigidity of the rolling mill is high, and the precise wedge transverse rolling can be realized.

3. The integral type die is adopted, the roller can be changed quickly, the integral type die can still ensure higher precision than a split type die after heat treatment, the problem that the lower roller of the vertical rolling mill is difficult to change is solved by adopting a horizontal shaft system unit arrangement mode, the roller can be changed quickly, and the production efficiency is obviously improved.

4. The concave-convex circle synchronous unit is adopted, so that the gap problem generated in the meshing rotation process is greatly reduced, the synchronous centering opening and closing of the two frames can be ensured, and the rolling central line is not deviated when the distance between the rollers is adjusted.

5. And a pre-tightening spring is arranged between the left shafting unit and the right shafting unit, so that necessary pre-tightening force is provided for the cross wedge rolling process, and the high cross wedge rolling precision is ensured.

6. The roller distance can be directly adjusted by rotating the locking nut with scales, and the installation and debugging are simple.

7. The radial rolling force in the cross wedge rolling process can be obtained in real time through the pressure sensor arranged in the rack, and an experimental platform is provided for researching the change condition of the rolling force in the cross wedge rolling forming process and deeply analyzing the rolling mechanism.

Drawings

Fig. 1A is a schematic structural diagram of a tilting type precision cross wedge rolling forming device according to an embodiment of the present invention.

FIG. 1B is a schematic side view of a precision cross wedge rolling apparatus according to an embodiment.

Fig. 2 is a schematic view of an embodiment of a supporting frame.

Fig. 3 is a schematic view of an integrated cross wedge rolling die in the embodiment.

Fig. 4 is a schematic diagram of a concavo-convex circle synchronizing unit in the embodiment.

Fig. 5 is a diagram showing a comparison between the meshing of the concavo-convex circular synchronizing unit and the conventional gear in the embodiment.

Fig. 6 is a schematic diagram illustrating the pre-tightening force of the pre-tightening spring in the embodiment.

FIG. 7 is a graph showing the relationship between the rolling force and the whole run-out deformation of the rolling mill by adding pre-tightening springs between shafting and compressing the pre-tightening springs to provide enough pre-tightening force.

In the figure, 1, a rack unit; 2. an integral mold; 3. a cylindrical gasket; 4. a shafting unit; 5. a roll gap adjusting unit; 6. a guide plate feeding unit; 7. a synchronization unit; 8. a base; 9-a hoist tilt unit; A. a roll gap adjusting unit mounting groove; B. a shafting unit mounting groove; C. a synchronization unit mounting groove; D. and a rotating shaft mounting hole.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that technical features or combinations of technical features described in the following embodiments should not be considered as being isolated, and they may be combined with each other to achieve better technical effects. In the drawings of the embodiments described below, the same reference numerals appearing in the respective drawings denote the same features or components, and may be applied to different embodiments.

In the following embodiments, for convenience of description, the two racks are expressed as a left rack and a right rack; the two axis systems are expressed as a left axis system and a right axis system; the two molds are expressed as a left mold and a right mold. Here, the left and right distinction is only a distinction of relative positions, and may be made in the following. The contents of the examples should not be taken as limiting the scope of protection.

As shown in fig. 1A and fig. 1B, an inclined precision wedge cross rolling forming apparatus according to an embodiment of the present invention includes a frame unit 1, an integral mold 2, a cylindrical washer 3, a right axis unit 4, a roll gap adjusting unit 5, a guide plate feeding unit 6, a synchronizing unit 7, a base 8, and a lifting and inclining unit 9. The frame unit 1 is symmetrically arranged on the base 8 through a rotating shaft; the guide plate feeding unit 6 is symmetrically arranged above the base 8 about a central axis; the left and right moulds 2 are coaxially fixed by a left shaft system and a right shaft system respectively; the driving unit is coaxially arranged on the shafting unit 4 and drives the die 2 to rotate; the roll spacing adjusting unit 5 is arranged above the rolling mill frame in a penetrating mode, and the size of the distance between the dies 2 is adjusted by controlling the opening degree of the rolling mill frame; the synchronous units 7 are symmetrically arranged below the rolling mill frames to ensure that the two frames are synchronously opened and closed; the lifting inclined unit 9 is arranged below the base 8 and provides a required inclined angle of the rolling mill by controlling the lifting height. The metal blank reaches a designated position through the guide plate feeding unit 6, the roller spacing is adjusted to a designated numerical value through the roller spacing adjusting unit 5, and the driving unit provides rolling power to carry out wedge transverse rolling on the metal blank to obtain a required product.

As shown in fig. 1A and 1B, the stand unit 1 is mounted on the rolling mill base 8 through the synchronization unit 7 and the stand rotating shaft, and the integral die 2 is coaxially connected with the shafting unit 4. The shafting unit 4 provided with the integral die 2 is fixedly arranged on the bearing type frame through a shafting unit mounting groove B. The left frame and the right frame are connected in series through the roll spacing adjusting unit 5, and pretightening force is provided through a pretightening spring between the shafting units 4, so that the stability of the cross wedge rolling process is ensured. The guide plate feeding unit 6 ensures that the axial height of the blank is consistent with the axial height of the left shafting and the right shafting.

As shown in fig. 1B, the rolling mill main body mechanism is seated on a rolling mill base 8, and the base 8 is abutted on one end against the ground and lifted by a lifting and tilting unit 9 at the other end, arranged at a corresponding tilt angle α to the ground. Alpha is more than or equal to 15 degrees and less than or equal to 35 degrees.

As shown in fig. 2, the supporting frame is provided with a roller spacing adjustment unit mounting groove a, a shafting unit mounting groove B, a synchronization unit mounting groove C, and a rotating shaft mounting hole D. Through the grooves arranged above, the roll spacing adjusting unit 5, the shafting unit 4, the synchronizing unit 7 and the rack rotating shaft can be directly and fixedly arranged on the rack, and the rolling force in the cross wedge rolling process is directly transmitted to the rack, so that the high rigidity and small jump of the rolling mill in the cross wedge rolling process are ensured, and the precise cross wedge rolling is realized.

As shown in figure 3, the device adopts an integral cross wedge rolling die 2, the die 2 is arranged at a specified position in a shafting unit 4 through a key slot, and the axial positions of a left die and a right die are ensured to be the same through adjusting the thickness of a gasket.

As shown in figures 4 and 5, the device adopts the concave-convex circle synchronization unit 7 to ensure that the left stand and the right stand of the rolling mill are synchronously opened and closed, the rolling center line does not deviate, and the rolling center line is always positioned at a central symmetrical position. Wherein set up straight section in the synchronous concave circular groove to guarantee that synchronous protruding circle piece and synchronous concave circular groove external toothing rotate in-process centre-to-centre spacing not change, prevent to produce the clearance among the meshing process and lead to rolling mill whole central line to take place the skew, and then influence rolling precision.

As shown in fig. 5, in the process of meshing and rotating the traditional gear, the two-dimensional plane inner teeth and the teeth are all in point contact, stress is concentrated, gear pitting corrosion is easily caused, and the rolling precision is poor due to large gaps. In the invention, the concave-convex circle synchronous unit 7 is adopted to control the frame to rotate, so that a small enough gap is ensured at any time in the meshing rotation process, the rolling precision is high, and the precise cross wedge rolling forming can be realized.

As shown in FIG. 7, the pre-tightening springs are added between the shafting, and the pre-tightening springs are compressed to provide enough pre-tightening force, so that the integral jumping deformation of the rolling mill caused by counter force caused by metal extrusion in the cross wedge rolling forming process is greatly reduced, and further, the precise cross wedge rolling is realized.

The invention achieves the main mechanism analysis of precision rolling:

1. the convex round block and the concave round groove are meshed and rotated: the gap can be minimized.

In the conventional gear meshing, as shown in fig. 5, for smooth assembly, a gap is required (if no gap exists, the assembly cannot be performed, the center distance between two gears cannot be guaranteed to be a set value or the two gears cannot be directly clamped and cannot be used), and the gap for assembling the gears is usually 0.1-0.15mm, namely, the gap between teeth is minimum when the gears are straight; when the rack is opened to the limit position, the gear meshing also reaches the limit position, the gap is overlapped, the gap of the limit position can reach the maximum, and in the use process of actual equipment, the gap of the limit position is large and is very sloshing, and the gap can reach 0.2-0.3 mm.

The convex and concave circles are arranged, so that the gap between the convex circle and the groove can be controlled to be small, even stuck and seamless in the processing process, and the gear cannot shake due to the assembly gap when the gear is meshed and placed straightly or slightly twisted (the convex circle and the groove cannot be tightly stuck due to the fact that the gear is meshed and placed straightly), and no shaking occurs. Even when the asperities are at the extreme positions, there are two points of contact, as shown in fig. 6: the contact of the two points limits the shaking between the convex round block and the concave round groove and ensures that the shaking between the concave round and the convex round can not occur. Therefore, the gap of the concave-convex circle setting limit position is the same as that of the straight installation position, and the gap is very small and does not change along with the position. The gears are engaged in the opposite way, the horizontal placement has a smaller clearance but still has 0.1-0.15mm, and the limit position has a larger clearance. For wedge cross rolling forming of shaft parts with middle and small diameters of phi 10-phi 70, the meshing rolling precision of the traditional gear is +/-1.5 mm; the rolling precision obtained by adopting the concave-convex circle device is +/-0.5 mm, and the rolling precision is improved by about 1 mm.

2. The function of the pre-tightening spring is as follows:

as shown in fig. 7, mechanical equipment such as a rolling mill has a certain assembly gap inside the equipment (after assembly, parts are loose, have a certain gap, and are not tightly stretched together). When the pre-tightening spring is not arranged, the rolled piece is subjected to rolling force provided by the rolling mill in the rolling process, meanwhile, each part of the rolling mill is subjected to rolling counter force, and the rolling counter force has a tendency of outward expansion to the two racks so as to open the racks. However, because a certain assembly gap exists inside the mechanical equipment (the assembly process determines that a certain gap necessarily exists between each component, and cannot be completely tightened, the gap comes from the inside of the machine, and the assembly process determines that the gap cannot be eliminated), the rolling reaction force applied to the rolling mill firstly compensates the gap inside the equipment, and a certain jumping amount is caused, as shown in the section OA in fig. 7; after the internal clearance is compensated, the rolling force and the deformation of the rolling mill are in a linear relation, the larger the rolling force is, the larger the deformation of the rolling mill is, and the larger the runout is, as shown in an AB section. When the rolling process is finished, the force disappears rapidly, the rack is folded back, the parts of the equipment are loosened back due to the disappearance of the force, and the rolling mill has larger runout amount and low precision of rolled parts in the rolling process due to the repetition of the process.

After the pre-tightening spring is added, the assembly gap between each part in the rolling mill is compensated by the counterforce generated by compressing the pre-tightening spring. Therefore, after the assembly gaps among the components in the rolling mill are compensated by the pretightening force, the rolled pieces are put into the rolling mill for rolling, the gaps in the rolling reaction force compensation equipment are not needed, after the jumping quantity generated by the assembly gaps among the components in the equipment is reduced, the jumping quantity of the rolling mill is reduced by one section in the whole rolling process, and as shown in an OCD section in fig. 7, the precision of rolled parts is high. (the runout caused by the looseness and the assembly clearance in the rolling mill is far larger than the runout caused by the deformation of the rolling mill caused by the rolling force; because the rolling mill has very large rigidity, the deformation caused by the rolling force is actually very small, but the runout caused by the tightness and the looseness in the rolling mill caused by the rolling force is very large).

For wedge transverse rolling forming of shaft parts with middle and small diameters of phi 10-phi 70, when a pre-tightening spring is not added, the inside of the whole rolling mill is slightly loose, and the rolling runout is about 0.3-0.5 mm; the pre-tightening spring is added, after the interior of the rolling mill is loosened through pre-tightening force compensation, the rolling runout can be controlled to be about 0.05-0.15mm (0.12 mm or 0.1mm is measured by an actual dial indicator of equipment), and the runout is obviously improved.

For the whole equipment, the concave-convex circle setting improves the effect: the pre-tightening spring has an improvement effect =7: 3.

The working principle of the invention is as follows:

the whole device adopts inclined arrangement, realizes automatic feeding and discharging by utilizing the dead weight of metal blanks, and adopts a bearing type frame, an integral cross wedge rolling die 2, a concave-convex circle synchronous unit 7 and a pre-tightening spring to improve the whole height of the rolling mill, reduce the jumping quantity in the rolling process and further realize precise cross wedge rolling. The blank with the diameter of phi 10-phi 70 heated to the rolling temperature (cold rolling to room temperature and hot rolling to 700-1200 ℃) is transferred into the device, the driving unit provides power, the input power is respectively transmitted to the left and the right dies 2 through the shafting unit 4, the left and the right dies 2 are driven to rotate synchronously in the same direction, and the blank is formed by wedge cross rolling between the left and the right wedge cross rolling dies 2 under the action of the friction force of the dies and the blank.

At the moment that the rolled piece after the cross wedge rolling forming is separated from the die, the rolling mill slides out of the rolling mill along the discharging frame under the action of self gravity due to the inclination angle of the rolling mill.

The invention has the advantages of high rolling precision, convenient die replacement, high automation degree and the like, can realize quick feeding and discharging by utilizing the self weight of a rolled piece, and obviously improves the production efficiency.

While several embodiments of the present invention have been presented herein, it will be appreciated by those skilled in the art that changes may be made to the embodiments herein without departing from the spirit of the invention. The above examples are merely illustrative and should not be taken as limiting the scope of the invention.

Claims

1. An inclined type precise wedge cross rolling forming device is characterized by comprising a rack unit, a shafting unit, a roll spacing adjusting unit, a guide plate feeding unit, a synchronizing unit, a driving unit, a base and a hoisting inclined unit;

the rack unit is mounted on the base;

2. The inclined precision cross wedge rolling forming device according to claim 1, wherein the left frame and the right frame are both load bearing frames; the upper parts of the left stand and the right stand are respectively provided with a roller spacing adjusting unit revolute pair mounting hole, the middle parts of the left stand and the right stand are respectively provided with a shafting unit mounting groove, and the lower parts of the left stand and the right stand are respectively provided with a rotating shaft mounting hole; the left frame and the right frame are installed on the base through frame rotating shafts.

3. The inclined precision cross wedge rolling forming device according to claim 1, wherein the synchronizing unit comprises two convex circular blocks and two concave circular grooves; when the convex round block and the concave round groove are meshed and rotate, the left frame and the right frame are driven to synchronously open and close around the rotating shaft of the frame in a constant speed and reverse direction.

4. The inclined precision cross wedge rolling forming device as claimed in claim 3, wherein the convex round block engagement part is a convex semicircle, the concave round groove engagement part is a concave semicircle, and the outer side of the concave semicircle is connected with the straight section; the convex round block and the concave round groove are meshed and rotate, and the rolling precision reaches 0.05mm-0.2 mm.

5. The inclined precision cross wedge rolling forming device as claimed in claim 1, wherein the shafting unit comprises a left shafting and a right shafting; the left shafting and the right shafting both comprise a main shaft, a feeding end bearing seat, a discharging end bearing seat, an adjusting washer and a pre-tightening spring;

a cross wedge rolling die is arranged on the main shaft; the adjusting washers are coaxially arranged on two sides of the cross wedge rolling die; the main shaft is supported by the feeding end bearing seat and the discharging end bearing seat together; the feeding end bearing block and the discharging end bearing block are fixedly arranged in a shaft system mounting groove in the middle of the rack through bolts; and a pre-tightening spring is arranged between the bearing seats at the discharge ends of the left shaft system and the right shaft system, and the axis of the pre-tightening spring is vertical to the axis of the blank.

6. The inclined precision cross wedge rolling forming device as claimed in claim 1, wherein the pre-tightening pressure F1 provided by the pre-tightening spring satisfies 0.1F < F1<0.3F, wherein F is the maximum rolling force provided by the rolling mill.

7. The inclined precision wedge cross rolling forming apparatus of claim 1, wherein said roll gap adjusting unit comprises a tie rod, a cylindrical washer, a lock nut, a dial and a pressure sensor;

the cylindrical gaskets are respectively arranged in the corresponding roller spacing adjusting unit grooves at the upper parts of the left frame and the right frame; one end of the pull rod is provided with a key groove to ensure that the pull rod and the rack do not rotate relatively; the locking nut is arranged at the tail part of the pull rod positioned at the outer side of the right rack, so that the left rack and the right rack are prevented from opening and jumping in the rolling process by screwing the locking nut; the dial is arranged on the locking nut, and the accurate adjustment of the roller distance is realized by rotating to a corresponding scale; the pressure sensor is arranged between the cylindrical gasket and the right rack, and feeds back the instantaneous rolling force in real time by measuring the extrusion force applied in the rolling process.

8. The inclined precision cross wedge rolling forming device according to claim 1, wherein the guide plate feeding unit comprises a feeding frame, a guide plate and a discharging frame; the feeding frame, the guide plate and the discharging frame are fixedly arranged on the base through bolts; the feeding frame is provided with a material guide rail, so that the blank can smoothly enter an accurate position corresponding to the cross wedge rolling die.

9. The inclined precision cross wedge rolling forming apparatus of claim 1 wherein said lift tilt unit is mounted below a mill base, said base being provided with a corresponding tilt angle α by said lift unit, α satisfying 15 ° α ≦ 35 °.

10. The inclined precision cross wedge rolling forming device as claimed in claim 1, wherein the blank is a shaft part with a diameter of 10-70 mm, and is used for cold precision cross wedge rolling or hot precision cross wedge rolling; the cold rolling temperature is room temperature, and the hot rolling temperature is 700-1200 ℃.