CN210435370U

CN210435370U - Special numerical control machine tool for machining turning shaft parts

Info

Publication number: CN210435370U
Application number: CN201920884179.XU
Authority: CN
Inventors: 施文秀; 于学奎; 杜武; 李刚; 王菊芳; 李旭
Original assignee: Ningxia Changxing Precision Machinery Co ltd
Current assignee: Ningxia Changxing Precision Machinery Co ltd
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-05-01
Anticipated expiration: 2029-06-13

Abstract

The utility model relates to a numerical control machine tool, in particular to a special numerical control machine tool for processing axle parts, which comprises a machine tool body, two main shaft boxes arranged on the machine tool body, two tail frames, two tool tables and a machine tool electric control device, wherein one tail frame can move up and down; a material supporting barrel is fixedly arranged in a main shaft hole in the main shaft box, and a universal ball is fixed on the inner wall of the material supporting barrel; and workpiece axial measuring devices are arranged on two sides of the two spindle boxes. According to the technical scheme, on the basis of the existing double-spindle numerical control machine tool, for meeting the requirements of loading and unloading of long-axis parts with large major diameters and accurate measurement of axial length, the structures in the tailstock and the spindle on one side are improved, and meanwhile, the left and right axial length measuring devices are additionally arranged on the machine tool.

Description

Special numerical control machine tool for machining turning shaft parts

Technical Field

The utility model relates to a digit control machine tool, especially a special digit control machine tool of processing axletree class part.

Background

At present, when shaft parts are machined, a double-spindle-box numerical control lathe has the characteristics of high machining efficiency and high machining precision and is widely used. When a long shaft part with more complicated processing procedures, such as an axle of a freight automobile, is processed, the processing procedures are as follows: the processing both ends face, both ends excircle and hole, so need divide two processes to process under the condition of not dismantling the work piece, first process presss from both sides the excircle and processes terminal surface and hole, and the second process tailstock withstands work piece both ends hole processing excircle, and when utilizing current two headstock numerical control lathe to process above-mentioned axle type part, the main problem that exists has following several: 1. the tailstock at two ends of the existing double-spindle-box machine tool is fixed, and when long-shaft parts are assembled and disassembled, a crane is needed to manually carry out loading and unloading work, so that the machining efficiency is seriously influenced; 2. because some long shaft parts have requirements on the axial dimension between the shaft shoulders at the two ends, the measurement parts of the two shaft shoulders are positioned at the left end and the right end of the two spindle boxes in the machining process, so that the axial measurement is difficult, and the dimensional accuracy cannot be ensured.

Disclosure of Invention

The utility model aims at overcoming prior art's defect, providing a movable and positioning accuracy who resets of headstock one end tailstock on the one hand is good, and on the other hand possesses the special digit control machine tool of axial length automatic measure's processing axletree class part.

In order to achieve the above purpose, the technical scheme of the utility model is that: a special numerical control machine tool for processing axle parts comprises a machine tool body, a main spindle box, an auxiliary spindle box, a right tail frame, a left tail frame, a right tool post, a left tool post and a machine tool electrical control device, wherein the main spindle box, the auxiliary spindle box, the right tail frame, the left tail frame, the right tool post, the left tool post and the machine tool electrical control device are arranged on the machine tool body; a material supporting cylinder is fixedly arranged in a main shaft hole in the main spindle box, and a universal ball is fixed on the inner wall of the material supporting cylinder; the left tailstock consists of a tailstock body, a tailstock sliding body and a base, wherein the tailstock body is fixedly arranged on the tailstock sliding body, the tailstock sliding body is arranged on a pair of guide rails A on the base, a tailstock sliding body locking device and a tailstock sliding body positioning device are arranged between the tailstock sliding body and the base, an oil cylinder is arranged between the base and the tailstock sliding body, an oil cylinder body is fixed on the base, and a piston rod is connected with the tailstock sliding body; the tailstock structure comprises a tailstock body, a movable tailstock sleeve is arranged in the tailstock body, a rotatable core shaft with a taper hole is fixedly arranged in an inner hole at the front end of the tailstock sleeve, and a driving device capable of driving the tailstock sleeve to move linearly is arranged at the rear end of the tailstock sleeve.

The section of the inner hole of the material supporting barrel is a square with an excessive fillet, and the universal balls are uniformly distributed along the length direction of each edge of the square inner hole of the material supporting barrel.

The tailstock locking device comprises a pressing plate positioned on the lower end face of the guide rail A and a tailstock sliding body locking oil cylinder fixed on a tailstock sliding body, piston rods extend out of the upper end and the lower end of the tailstock sliding body locking oil cylinder, a lower piston rod is fixedly connected with the pressing plate, and a reset pressure spring is installed on an upper piston rod.

The tailstock body is provided with a sleeve locking oil cylinder, the sleeve locking oil cylinder is internally provided with two opposite pistons and a pressure spring arranged between opposite end faces of the pistons, and the outer circular faces of the opposite ends of the two pistons are provided with circular arc faces matched with the excircle of the tailstock sleeve.

The driving device for driving the tailstock sleeve to linearly move is a driving oil cylinder, a cylinder body of the driving oil cylinder is composed of a tailstock sleeve inner hole, a partition plate is arranged in the middle of the tailstock sleeve inner hole, a sealing flange is arranged at the tail of the tailstock sleeve, a piston I is arranged in the tailstock sleeve inner hole between the partition plate and the sealing flange, an end cover is arranged on a tailstock body corresponding to the tail of the tailstock sleeve, a piston rod extends out of the sealing flange and the end cover and is fixedly connected with an adjusting plate fixed on the outer side of the end cover, and an adjusting bolt is arranged on the adjusting plate.

The tailstock sliding body positioning device is symmetrically arranged on two sides of the guide rail A and consists of positioning cylinder oil arranged on the base and a positioning block arranged on the tailstock sliding body, a conical positioning pin is arranged at the upper end of a piston rod I in the positioning cylinder, and a positioning groove matched with the positioning pin is arranged on the positioning block.

The left axial length measuring device consists of a left bottom plate fixedly connected with the lathe bed, a driving mechanism and a measuring device, wherein the driving mechanism and the measuring device are installed on the left bottom plate; a supporting plate is fixed on one side of the upper end of the fixing plate, a supporting seat is installed on the supporting plate, and the connecting shaft is fixed on the supporting plate through the supporting seat; a left pneumatic measuring device is fixed at one end of the connecting plate, the other end of the connecting plate is fixedly connected with one end of the connecting shaft, the other end of the connecting shaft is fixedly connected with one end of the swing arm, the other end of the swing arm is hinged to a piston rod in the swing cylinder, and a cylinder body of the swing cylinder is connected with the support in a swinging mode.

The guide rail B is a linear guide rail, and a sliding seat matched with the linear guide rail is fixed on the fixing plate A.

The right axial length measuring device consists of a right bottom plate connected with the lathe bed, a driving device and a measuring device, wherein the driving device and the measuring device are arranged on the right bottom plate; a fixing plate B is fixed on one side of a swing cylinder on an L-shaped support, the lower ends of two connecting rods are hinged to a fixing plate I, the upper ends of the two connecting rods are hinged to a connecting plate I, a piston rod in the swing cylinder is hinged to the middle of one of the two connecting rods, and a right pneumatic measuring device is mounted on the connecting plate.

The two ends of the two connecting rods are hinged to each other through fixing seats which are vertically arranged on the fixing plate B and the connecting plate I, pin shafts are arranged on the fixing seats, and holes matched with the pin shafts are formed in the two ends of the connecting rods; the guide rail I is a linear guide rail, and a sliding seat I matched with the linear guide rail is fixed on the L-shaped support.

The technical scheme of the utility model has following characteristics: 1. the tailstock is driven by an oil cylinder to move up and down, the tailstock is positioned at the lower position during the first processing, the tailstock is driven by the oil cylinder to enable the center of the tailstock to coincide with the center of a machine tool spindle during the second processing, and the workpiece is jacked by a center to process the excircles at two ends; the tail seat is positioned at the lower position when the workpiece is loaded and unloaded, the workpiece can be supported by the universal ball arranged in the spindle hole and moves axially along the spindle hole to load and unload materials, and automatic loading and unloading are realized; 2. a tailstock sliding body positioning device is arranged between the base and the tailstock sliding body, so that the relative coincidence precision of the tailstock center and the machine tool center in the machining process can be ensured; 3. the tailstock sleeve can move relative to the tailstock body, so that the workpiece can be pushed tightly when the workpiece is different in length; 4. the tailstock has the characteristics of reasonable structure, convenience in use and the like, is very suitable for axle parts, and is particularly suitable for axle parts machined on a double-spindle double-end-face numerical control lathe; 5. the pair of pneumatic measuring devices are adopted to measure two ends of a measured workpiece at the same time, and measurement data are directly fed back to a numerical control system of a machine tool for tool compensation of the numerical control system, so that a simple and effective method is provided for accurate and automatic measurement of the axial dimension of long-axis parts; 6. reasonable structure and small occupied space. When the device is used, the measuring device is pushed to a measuring position through the air cylinder, and can be recovered to a small space after the measurement is finished, so that the whole processing process is not influenced; 7. the measuring device is driven by the air cylinder, and has the advantages of simple structure, convenient adjustment and low failure rate.

In conclusion, according to the technical scheme, on the basis of the existing double-spindle numerical control machine tool, in order to meet the requirements of loading and unloading of long-axis parts with large major diameters and accurate measurement of axial length, the structures in the tailstock and the spindle on one side are improved, and meanwhile, the left and right axial length measuring devices are additionally arranged on the machine tool.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the left axial length measuring device of the present invention in an operating state;

fig. 3 is a schematic top view of fig. 2 of the present invention;

fig. 4 is a schematic diagram of the right-view structure of fig. 2 of the present invention;

FIG. 5 is a schematic structural view of the left axial length measuring device in a retracted state;

FIG. 6 is a schematic structural view of the right axial length measuring device of the present invention in an operating state;

fig. 7 is a schematic top view of fig. 6 according to the present invention;

FIG. 8 is a schematic view of the structure of the right axial length measuring device in a retracted state;

FIG. 9 is a schematic structural view of the main spindle in the main spindle box of the present invention;

fig. 10 is a schematic sectional view taken along line a-a of fig. 9 according to the present invention;

FIG. 11 is a schematic view of the supporting round material of the present invention;

FIG. 12 is a schematic view of the supporting square stock of the present invention;

FIG. 13 is a schematic view of the left tailstock of the present invention;

fig. 14 is a right side view of fig. 13 of the present invention;

fig. 15 is a left side view of fig. 13 according to the present invention.

Detailed Description

In the drawings 1 to 15, 1 is a left tailstock, 1-1 is a tailstock body, 1-1-1 is a tailstock sleeve, 1-1-2 is a mandrel, 1-2 is a tailstock sliding body, 1-3 is a base, 1-4 is a guide rail A, 1-5 is a tailstock locking device, 1-5-1 is a lower piston rod, 1-5-2 is a piston, 1-5-3 is a reset pressure spring, 1-6 is a pressure plate, 1-7 is a driving device, 1-7-1 is an adjusting plate, 1-7-2 is an end cover, 1-7-3 is a cavity, 1-7-4 is a clapboard, 1-7-5 is a piston I, 1-7-6 is a sealing flange, 1-7-7 is an adjusting bolt, 1-8 is a sleeve locking device, 1-8-1 is an oil inlet, 1-8-2 is a piston II, 1-8-3 is a pressure spring, 1-9 is a tailstock sliding body positioning device, 1-9-1 is a piston rod, 1-9-2 is a piston III, 1-9-3 is a positioning pin, 1-9-4 is a positioning block, 1-10 is an oil cylinder, 1-10-1 is a piston rod I, 2 is a left knife rest, 3 is a left axial length measuring device, 3-1 is a push-out cylinder, 3-2 is a connecting shaft, 3-3 is a swing cylinder, 3-4 is a fixing plate A, 3-5 is a guide rail B, 3-6 is a left bottom plate, 3-7 is a side plate, 3-8 is a sliding seat, 3-9 is a swing arm, 3-10 is a supporting plate, 3-11 is a left pneumatic measuring head, 3-12 is a connecting plate, 3-13 is a left pneumatic measuring device, 3-14 is a supporting seat, 3-15 is a support, 4 is a main spindle box, 4-1 is a main spindle, 4-2 is a material supporting barrel, 4-3 is a universal ball, 4-4 is a workpiece, 5 is a lathe bed, 6 is an auxiliary spindle box, 7 is a right axial length measuring device, 7-1 is a connecting rod, 7-2 is a fixed seat, 7-3 is a fixed plate B, 7-4 is a swing cylinder, 7-5 is a push-out cylinder I, 7-6 is a support, 7-7 is an L-shaped support, 7-8 is a side plate I, 7-9 is a guide rail I, 7-10 is a right bottom plate, 7-11 is a sliding seat I, 7-12 is a connecting plate I, 7-13 is a right pneumatic measuring device, 7-14 is a right measuring head, A right tail frame 8 and a right knife rest 9.

As shown in fig. 1, a main headstock 4 and an auxiliary headstock 6 are mounted on a bed 5, a left tailstock 1 and a left tool post 2 are mounted on the left side of the main headstock, a right tailstock 8 and a right tool post 9 are mounted on the right side of the auxiliary headstock, a left axial length measuring device 3 is mounted on the bed between the main headstock and the left tailstock, and a right axial length measuring device 7 is mounted on the bed between the auxiliary headstock and the right tailstock.

As shown in fig. 2, 3, 4 and 5, two parallel guide rails B3-5 are fixed on the left bottom plate, a fixing plate A3-4 is installed on the guide rails a, the cylinder body of the push-out cylinder 3-1 and the bracket 3-15 are fixed on the fixing plate, the piston rod in the push-out cylinder is fixed on the side plate 3-7, and the side plate is fixed on the left side of the bottom plate; a supporting plate 3-10 is fixed on one side of the upper end of the fixing plate A, a supporting seat 3-14 is installed on the supporting plate, a connecting shaft 3-2 is fixed on the supporting plate through the supporting seat, the left end of the connecting shaft is fixed with one end of a connecting plate 3-12, the other end of the connecting plate is fixedly connected with a pneumatic measuring device 13, the right end of the connecting shaft is fixedly connected with one end of a swing arm 3-9, the other end of the swing arm is hinged with a piston rod in a swing cylinder 3-3, and a cylinder body of the swing cylinder is connected with a support 3. The guide rail A3-5 is a linear guide rail, and a sliding seat 3-8 matched with the linear guide rail is fixed on a fixed plate 3-4.

When the axial size of a machined part needs to be measured, the push-out cylinder works, a piston rod of the push-out cylinder is fixed with the left bottom plate through a side plate, a cylinder body of the push-out cylinder drives the fixing plate A, the sliding seat moves leftwards along the linear guide rail, after the sliding seat moves in place, the swing cylinder works, the piston rod in the swing cylinder moves downwards to drive the swing arm to rotate anticlockwise along the connecting shaft, the swing arm drives the connecting shaft to rotate anticlockwise, after the connecting shaft drives the connecting plate to rotate anticlockwise in place, and a pneumatic measuring head fixed in a pneumatic measuring device at the left end of the connecting plate stretches out rightwards to contact with a.

As shown in fig. 6, 7 and 8, two parallel guide rails I7-9 are fixed on a right bottom plate 7-10, the guide rails adopt linear guide rails, a sliding seat I7-11 matched with the linear guide rails is fixed on an L-shaped bracket 7-7, a side plate I7-8 is installed on the right side of the right bottom plate, a cylinder body in a push-out cylinder I7-5 is fixed on the right side of the L-shaped bracket, a piston rod in the push-out cylinder I is fixed on the side plate I, and a swing cylinder 7-4 is hinged on the left side of the L-shaped bracket; a fixing plate B7-3 is fixed on the left side of the L-shaped support, the lower ends of two connecting rods 7-1 are hinged on the fixing plate B, the upper ends of the two connecting rods are hinged on a connecting plate 7-12, a piston rod in the swing cylinder is hinged with the middle of one connecting rod on the left side of the two connecting rods, and a right pneumatic measuring device 7-13 is installed on the connecting plate.

The two connecting rods, the fixed plate and the connecting plate form a plane four-bar mechanism.

When the axial dimension of a machined part needs to be measured, the push-out cylinder I works, a piston rod of the push-out cylinder I is fixed with the right bottom plate through the side plate I, a cylinder body of the push-out cylinder I drives the L-shaped support, the sliding seat moves leftwards along the linear guide rail, after the sliding seat moves in place, the swing cylinder works, the piston rod in the swing cylinder stretches out leftwards, the connecting rod is driven to rotate anticlockwise along the fixing seat on the fixing plate B, after the right pneumatic measuring device installed on the connecting plate is driven to rotate anticlockwise in place, and the right measuring head in the pneumatic measuring device stretches out leftwards to contact with a measuring point on the.

Because the device is arranged at the position of the numerical control machine tool where a workpiece needs to be measured, the position between the left and right measuring devices is fixed, namely when the device extends out and the left and right pneumatic measuring devices rotate to the right, the position between the left and right pneumatic measuring heads is constant, and thus when the left and right pneumatic measuring heads move in opposite directions to contact with a measuring point, the distance between the left and right pneumatic measuring heads subtracts the moving distance of the two pneumatic measuring heads, namely the accurate distance of the axial measuring point of the workpiece to be measured. After the calculation and comparison are carried out by the numerical control system of the machine tool, the axial dimension of the machined part can be ensured by feeding back the calculation and comparison to the cutter compensation of the numerical control system.

As shown in fig. 9, 10, 11 and 12, a material supporting cylinder is fixedly installed in the main shaft hole, a universal ball is fixed on the inner wall of the material supporting cylinder, the section of the inner hole of the material supporting cylinder is a square with excessive fillets for ensuring that the universal ball can support workpieces with different sections, and the universal ball is uniformly distributed along the length direction of each edge of the square inner hole of the material supporting cylinder.

When a workpiece is conveyed into a hole of a main shaft in a main spindle box through a feeding device, the outer circle or two sides of the workpiece are in contact with the universal balls, the balls in the universal balls can roll in all directions, the universal balls have certain supporting capacity, the weight of the workpiece is evenly distributed on the material supporting barrel through the universal balls, the thrust required by axial movement of the workpiece is small, and the workpiece can be conveniently moved in place and clamped by a worker or a mechanical device to start processing.

The device can be used for adding the main shafts of machine tools of an inclined lathe bed and a horizontal lathe bed, and is particularly suitable for adding the main shafts of a numerical control lathe with double main shaft boxes or other machine tools.

As shown in fig. 13, 14, and 15, the base is fixed to the machine tool body, a pair of guide rails is provided on the base, the tailstock slide body is attached to the guide rails, and the tailstock body is fixed to the tailstock slide body. An oil cylinder is arranged between the base and the tailstock sliding body, wherein the cylinder body of the oil cylinder is fixed on the base, and the piston rod I is connected with the tailstock sliding body.

The tailstock locking device is arranged on the tailstock sliding body and consists of a pressing plate positioned on the lower end face of the guide rail and a tailstock sliding body locking oil cylinder fixed on the tailstock sliding body, piston rods extend out of two ends of a piston in the tailstock sliding body locking oil cylinder, a lower piston rod is fixedly connected with the pressing plate, and a reset pressure spring is installed on an upper piston rod.

The tailstock body is internally provided with a movable tailstock sleeve, the front end of the tailstock sleeve, namely an inner hole at the right end shown in figure 6, is fixedly provided with a rotatable core shaft with a taper hole, and the rear end of the tailstock sleeve, namely the left end shown in figure 1, is provided with a driving device capable of driving the tailstock sleeve to linearly move.

The driving device is a driving oil cylinder, the cylinder body of the driving oil cylinder is composed of a tailstock sleeve inner hole, a partition plate is arranged in the middle of the tailstock sleeve inner hole, the tailstock sleeve inner hole is divided into a left cavity and a right cavity which are relatively sealed, a sealing flange is arranged at the left end of the tailstock sleeve, namely the tail portion of the tailstock sleeve, a piston I is arranged in the tailstock sleeve inner hole between the partition plate and the sealing flange, an end cover is arranged on a tailstock body corresponding to the tail end of the tailstock sleeve, a piston rod extends out of the sealing flange and the end cover to be fixedly connected with an adjusting plate fixed on the outer side of the end cover, and an adjusting bolt is arranged.

The tailstock body is provided with a sleeve locking device, the sleeve locking device is a sleeve locking oil cylinder arranged on the tailstock body, two opposite pistons II and a pressure spring arranged between the opposite end faces of the pistons II are arranged in the sleeve locking oil cylinder, and the outer circular faces of the opposite ends of the two pistons II are provided with circular arc faces matched with the outer circle of the tailstock sleeve.

A tailstock sliding body positioning device is arranged between the base and the tailstock sliding body and consists of positioning cylinder oil arranged on the base and a positioning block arranged on the tailstock sliding body, a conical positioning pin is arranged at the upper end of a piston rod in the positioning cylinder, and a positioning groove matched with the positioning pin is arranged on the positioning block; the tailstock sliding body positioning device is provided with 2 sets of tailstock sliding body positioning devices, and the tailstock sliding body positioning devices are symmetrically arranged on two sides of the guide rail.

When processing, move the base to the lower position, be convenient for load and unload the work piece, according to work piece length and machining length and centre gripping length, rotatory adjusting bolt simultaneously, the left and right sides position of adjusting piston I in tailstock sleeve hole just can adjust the telescopic distance that moves of tailstock.

After the first sequence of workpieces is processed, a piston rod I in an oil cylinder fixed on a base extends out to drive a tailstock sliding body and a tailstock body to move upwards, after the workpieces are in place, oil is fed into an oil cavity on the left side of a piston III in two tailstock sliding body positioning devices, the piston III is pushed to move rightwards, a conical positioning pin is arranged on the right end of the piston rod and is inserted into a positioning groove in a positioning block, the tailstock sliding body is accurately positioned on the base, then the tailstock sliding body locks the oil fed into the cavity on the lower side of the piston in the oil cylinder to push the piston to move upwards, a pressing plate is driven to move upwards through a lower piston rod, and the tailstock sliding body is pressed and; then, oil is fed between a partition plate and a piston I in a driving oil cylinder which drives a tailstock sleeve to move linearly, the piston I is fixed, the tailstock sleeve moves rightwards under the driving of the partition plate, a top installed in a spindle taper hole is driven to abut against the left end of a workpiece to position the workpiece, then an oil inlet valve of a sleeve locking device is controlled to be opened, pressure oil is conveyed to two far ends of two pistons II through oil inlets to enable the two pistons II to approach relatively, an arc surface, matched with the excircle of the tailstock sleeve, on the excircle surfaces of the two pistons II is tightly pressed with the excircle of the tailstock sleeve, and the excircle surfaces of two ends of the workpiece can be machined after the tailstock sleeve is locked.

After the machining is finished, pressure oil in the sleeve locking device is decompressed, the two pistons II move up and down under the action of pressure springs on the opposite end faces of the pistons II, and the tailstock sleeve is unlocked; then, oil is fed into a cavity formed by the sealing flange and the piston I, and the tailstock sleeve is driven by the sealing flange to move leftwards, so that the center is separated from the workpiece; then, feeding oil to the right side of a piston III in the tailstock sliding body positioning device to push the piston III to move leftwards and drive a positioning pin to be separated from a positioning groove; then pressure oil in the tailstock locking device is decompressed, and the piston moves downwards under the action of a reset pressure spring to enable the pressure plate to leave the guide rail; and then the piston rod I moves downwards to drive the tailstock sliding body and the tailstock body to move downwards to the lowest position, so that the process of processing one workpiece is completed, and the workpiece moves rightwards from a main shaft hole in the main spindle box to a loading and unloading position.

Claims

1. A special numerical control machine tool for processing axle parts comprises a machine tool body, a main spindle box, an auxiliary spindle box, a right tail frame, a left tail frame, a right tool post, a left tool post and a machine tool electrical control device, wherein the main spindle box, the auxiliary spindle box, the right tail frame, the left tail frame, the right tool post, the left tool post and the machine tool electrical control device are arranged on the machine tool body, and the special numerical control machine tool is characterized in that a left axial length measuring device (3) is arranged on the machine tool body (5) between a main spindle box (4) and the left tail frame (1), and a right axial length measuring device (; a material supporting cylinder (4-3) is fixedly arranged in a main shaft (4-2) hole in a main spindle box (4), and a universal ball (4-4) is fixed on the inner wall of the material supporting cylinder; the left tailstock (1) consists of a tailstock body (1-1), a tailstock sliding body (1-2) and a base (1-3), wherein the tailstock body is fixedly arranged on the tailstock sliding body, the tailstock sliding body is arranged on a pair of guide rails A (1-4) on the base, a tailstock locking device (1-5) and a tailstock sliding body positioning device (1-9) are arranged between the tailstock sliding body and the base, an oil cylinder (1-10) is arranged between the base and the tailstock sliding body, the oil cylinder body is fixed on the base, and a piston rod is connected with the tailstock sliding body; the tailstock structure is characterized in that a movable tailstock sleeve (1-1-1) is arranged in a tailstock body, a rotatable core shaft (1-1-2) with a taper hole is fixedly arranged in an inner hole at the front end of the tailstock sleeve, and a driving device capable of driving the tailstock sleeve to linearly move is arranged at the rear end of the tailstock sleeve.

2. The numerical control machine tool special for processing axle parts according to claim 1, characterized in that the cross section of the inner hole of the material holding cylinder (4-3) is square with excessive round corners, and the universal balls (4-4) are uniformly distributed along the length direction of each side of the square inner hole of the material holding cylinder (4-3).

3. The numerical control machine tool special for machining axle parts according to claim 2, characterized in that the tailstock locking device (1-5) is composed of a pressing plate (1-6) located on the lower end face of the guide rail a (1-4) and a tailstock slide body locking cylinder fixed on the tailstock slide body (1-2), piston rods are respectively arranged at the upper end and the lower end of the tailstock slide body locking cylinder to extend out, wherein the lower piston rod (1-5-1) is fixedly connected with the pressing plate, and the upper piston rod is provided with a reset pressure spring (1-5-3).

4. The numerical control machine tool special for machining axle parts according to claim 3, characterized in that a sleeve locking cylinder (1-8) is arranged on the tailstock body (1-1), two opposite pistons (1-8-3) and a compression spring (1-8-4) installed between the opposite end faces of the pistons are arranged in the sleeve locking cylinder, and the outer circular faces of the opposite ends of the two pistons are provided with circular arc faces matched with the outer circle of the tailstock sleeve (1-1-1).

5. The numerical control machine tool special for machining axle parts according to claim 4, characterized in that the driving device (1-7) for driving the tailstock sleeve (1-1-1) to move linearly is a driving cylinder, the cylinder body of the driving cylinder is composed of an inner hole of the tailstock sleeve, a partition plate (1-7-5) is arranged in the middle of the inner hole of the tailstock sleeve, a sealing flange (1-7-8) is arranged at the tail of the tailstock sleeve, a piston I (1-7-6) is arranged in the inner hole of the tailstock sleeve between the partition plate and the sealing flange, an end cover (1-7-2) is arranged on the tailstock body (1-1) corresponding to the tail of the tailstock sleeve, a piston rod extends out of the sealing flange and the end cover and is fixedly connected with an adjusting plate (1-7-1) fixed on the outer side of the end cover, the adjusting plate is provided with adjusting bolts (1-7-10).

6. The numerical control machine tool special for machining axle parts according to claim 5, characterized in that the tailstock slider positioning devices (1-9) are symmetrically arranged on both sides of the guide rail A (1-4) and are composed of positioning cylinder oil arranged on the base (1-3) and positioning blocks (1-9-5) arranged on the tailstock slider (1-2), the upper ends of piston rods I (1-9-2) in the positioning cylinder are provided with conical positioning pins (9-9-4), and the positioning blocks are provided with positioning grooves matched with the positioning pins.

7. The numerical control machine tool special for processing axle parts according to any one of the preceding claims, characterized in that the left axial length measuring device (3) is composed of a left bottom plate (3-6) fixedly connected with the machine body (5) and a driving mechanism and a measuring device arranged on the left bottom plate, two parallel guide rails B (3-5) are fixed on the left bottom plate, a fixing plate A (3-4) is arranged on the guide rails, a cylinder body of a pushing cylinder (3-1) and a bracket (3-15) are fixed on the fixing plate A, a piston rod in the pushing cylinder is fixed on a side plate (3-7) which is fixed on one side of the bottom plate; a supporting plate (3-10) is fixed on one side of the upper end of the fixing plate, a supporting seat (3-14) is arranged on the supporting plate, and the connecting shaft (3-2) is fixed on the supporting plate through the supporting seat; one end of the connecting plate (3-12) is fixed with a left pneumatic measuring device (3-13), the other end of the connecting plate is fixedly connected with one end of a connecting shaft, the other end of the connecting shaft is fixedly connected with one end of a swing arm (3-9), the other end of the swing arm is hinged with a piston rod in a swing cylinder, and a cylinder body of the swing cylinder is connected with the support in a swinging mode.

8. The numerical control machine tool for machining axle parts according to claim 7, wherein the guide rails B (3-5) are linear guide rails, and the slide carriages (3-8) matching the linear guide rails are fixed on the fixed plates A (3-4).

9. The numerical control machine tool special for processing axle parts according to claim 8, characterized in that the right axial length measuring device (7) is composed of a right bottom plate (7-10) connected with the machine body (5) and a driving device and a measuring device arranged on the right bottom plate, a pair of parallel guide rails I (7-9) is fixedly arranged on the right bottom plate, a side plate I (7-8) is arranged on one side of the right bottom plate, an L-shaped bracket (7-7) is arranged on the guide rails, a cylinder body in a push-out cylinder I (7-5) is fixed on the L-shaped bracket, a piston rod in the push-out cylinder I is fixed on the side plate, and a swing cylinder (7-4) is hinged on the L-shaped bracket; a fixed plate B (7-3) is fixed on one side of a swing cylinder on an L-shaped support, the lower ends of two connecting rods are hinged to a fixed plate I, the upper ends of the two connecting rods are hinged to a connecting plate I (7-12), a piston rod in the swing cylinder is hinged to the middle of one of the two connecting rods (7-1), and a right pneumatic measuring device (7-13) is installed on the connecting plate.

10. The numerical control machine tool special for processing axle parts according to claim 9, characterized in that the two ends of the two connecting rods (7-1) are hinged by a fixed seat vertically arranged on the fixed plate B (7-3) and the connecting plate I (7-12), a pin shaft is arranged on the fixed seat, and holes matched with the pin shaft are arranged at the two ends of the connecting rod (7-1); the guide rails I (7-9) are linear guide rails, and sliding seats I (7-11) matched with the linear guide rails are fixed on the L-shaped supports (7-7).