CN110342348A - Automatic expanding and contracting shaft - Google Patents

Abstract

The utility model provides an automatic axle that contracts expands, including the support sleeve, driving motor, pivot and fixed setting in the support sleeve and with a plurality of modules that contract expand of pivot fixed connection, driving motor, pivot and the module that contracts expand all set up in the support sleeve, be provided with a plurality of groups installation through-hole units that equal with the module quantity that contracts along the axial direction on the support sleeve's the outer wall, every group installation through-hole unit all includes a plurality of installation through-holes that circumference set up, the fixed one side that sets up in the support sleeve of driving motor, the one end of pivot and driving motor's output shaft, the module that contracts expands all includes the fixed disk, left side rotary disk, right side rotary disk and slider, evenly set up first arc slotted hole and the second arc slotted hole that just the slope set up with the axial through groove quantity relatively respectively on left side rotary disk and the. The automatic expansion and contraction shaft realizes expansion and contraction of the expansion and contraction modules through electromechanical transmission, and the expansion and contraction modules are matched with the mounting through hole units respectively, so that the expansion and contraction modules are consistent in expansion and contraction.

Description

A self-expanding shaft

technical field

The invention belongs to the field of material processing technical equipment, and in particular relates to an automatic expansion and contraction shaft.

Background technique

When processing surface materials, the core tube is usually set on the take-up shaft first, and then the expansion shafts with different expansion methods and different shaft head structures are clamped between the clamping shafts of the winding and unwinding equipment to complete uncoiling and winding. coiled. Therefore, the expansion and contraction shaft is a common auxiliary tool for surface material processing.

According to the source of the driving force for expansion and contraction, common expansion and contraction shafts include pneumatic expansion and contraction shafts and mechanical expansion and contraction shafts. However, during the use of the common air-type expansion-contraction shaft, due to the influence of pressure gas fluctuations, the operation of the air-expansion shaft is unstable, which seriously affects the normal use of the winding and unwinding equipment. However, common mechanical expansion and contraction shafts generally need to be clamped manually, which is not conducive to realizing the automation of installation between the core tube and the expansion and contraction shaft.

Contents of the invention

The invention provides an automatic expansion and contraction shaft, which does not require manual clamping, and realizes expansion and contraction through electromechanical transmission, thereby effectively avoiding the instability of the gas expansion and contraction shaft.

In order to solve the problems of the technologies described above, the technical scheme adopted in the present invention is as follows:

An automatic expansion-contraction shaft, including a support sleeve, a drive motor, a rotating shaft, and several expansion-contraction modules fixedly arranged in the support sleeve and fixedly connected with the rotation shaft, the drive motor, the rotation shaft and the expansion-contraction modules are all arranged in the support sleeve ,

On the outer wall of the support sleeve, there are several groups of installation through-hole units equal to the number of expansion-contraction modules in the axial direction, and each group of installation through-hole units includes several installation through-holes arranged in the circumferential direction.

The driving motor is fixedly arranged on one side of the supporting sleeve, the axis of the rotating shaft is parallel to the axis of the supporting sleeve, and one end of the rotating shaft is connected with the output shaft of the driving motor.

A number of expansion and contraction modules are set in one-to-one correspondence with several groups of installation through-hole units,

The expansion and contraction modules all include a fixed plate, a left rotating plate, a right rotating plate and a slider,

The outer peripheral wall of the fixed plate is fixedly connected with the inner wall of the support sleeve, and a countersunk hole is set in both ends of the fixed plate, and a central through hole is opened in the fixed plate, and several holes are arranged on the outer wall of the fixed plate to be connected with the installation through hole unit. The installation through holes are opposite radial through holes, and an axial through groove communicating with each radial through hole is correspondingly opened on the fixed disk, and the left rotating disk and the right rotating disk are respectively rotated and sleeved at both ends of the fixed disk. In the counterbore, and the left rotating disc and the right rotating disc are fixedly connected with the rotating shaft, and the left rotating disc and the right rotating disc are evenly and oppositely provided with a first arc-shaped slot hole and a second arc-shaped slot hole with the same number as the axial through slot and inclined. Each radial through hole is provided with a slider. The slider includes a movable block slidably arranged in the radial through hole and two guide shafts relatively fixed on both sides of the movable block. The movable block can pass through the radial Extend the supporting sleeve toward the through hole and the corresponding installation through hole unit, and the two guide shafts are respectively clamped in the opposite first arc-shaped slot hole and the second arc-shaped slot hole and can be inserted into the corresponding axial through slot move.

Further, both ends of the support sleeve are provided with a support end cap and a shaft head, the support end cap is threadedly connected to the support sleeve, the drive motor is fixedly connected to the support end cap, the shaft head is located on the outside of the support end cap and connected to the support sleeve The inner wall of the cylinder is fixedly connected.

The supporting end caps are set, the driving motor is fixedly connected to one of the supporting end caps, the rotating shaft is connected to the output shaft of the driving motor, and the rotation is arranged between the two supporting end caps; the shaft head is set to connect the winding and unwinding equipment.

Further, an external plug is also included, the external plug is fixedly arranged in the central hole of the shaft head, and the external plug is electrically connected with the driving motor.

An external plug is set to supply power to the drive motor.

Further, a scale is provided on the outer wall of the support sleeve along the axial direction of the support sleeve.

The ruler is set, and after the mandrel is set into the mandrel, the position of the mandrel on the supporting sleeve can be conveniently adjusted according to the mandrel.

Further, the left rotating disk includes a first rotating disk base body and a hollow first sleeve shaft, the first rotating disk base body is uniformly provided with first arc-shaped slots equal in number to the axial through grooves and obliquely arranged on the upper circumference,

A first through hole is opened at the center of the first turntable base body, the first sleeve shaft is concentrically arranged with the first turntable base body, one end of the first sleeve shaft is fixedly connected with the first turntable base body, and the first sleeve shaft is sleeved on the rotating shaft and connected to the rotating shaft Fixed connection.

The first set of shafts is fixedly connected with the rotating shaft, and the rotation of the rotating shaft drives the rotation of the first set of shafts, thereby driving the rotation of the base body of the first turntable.

Further, the right rotating disk includes a second rotating disk base body and a hollow second sleeve shaft, and the second rotating disk base body is evenly provided with second arc-shaped slots in the circumferential direction that are equal in number to the axial through grooves and arranged obliquely,

A second through hole is opened at the center of the second turntable base body, the second sleeve shaft is arranged concentrically with the first turntable base body, one end of the second sleeve shaft is fixedly connected with the second turntable base body, and the second sleeve shaft sleeve is set on the rotating shaft and connected to the rotating shaft Fixed connection.

The second sleeve shaft is fixedly connected with the rotating shaft, and the rotation of the rotating shaft drives the rotation of the second sleeve shaft, thereby driving the rotation of the base body of the second turntable.

Further, the slider also includes a block, one end of the block is detachably connected to the movable block, and the other end of the block is provided with a number of grooves, and the other end of the block can follow the movable block from the installation through hole Support sleeve protrudes from the unit.

The clamping block is detachably connected with the movable block. When the clamping block or the movable block wears and affects the use, only the worn parts need to be replaced instead of the whole replacement, which saves cost and is easy to replace. There are grooves on the clamping block to enhance the sliding The friction between the block and the core barrel prevents slipping and makes the clamping more firm.

Compared with the prior art, the beneficial effects achieved by the present invention are at least as follows: the expansion and contraction of the expansion and contraction module is realized through electromechanical transmission, the instability of the gas expansion and contraction shaft is effectively avoided, and the automatic control of the expansion and contraction shaft is easy to realize; The expansion and contraction modules are respectively matched with each installation through-hole unit to make the external expansion and internal contraction of each expansion and contraction module consistent; setting a block with grooves can effectively prevent sliding between the support sleeve and the core barrel, Make the clamping more firm.

Description of drawings

Fig. 1 is a schematic structural diagram of an automatic expansion-contraction shaft provided by an embodiment of the present invention.

Fig. 2 is an external structural view of a support sleeve in an automatic expansion-contraction shaft provided by an embodiment of the present invention.

Fig. 3 is a schematic diagram of an expansion-contraction module in an automatic expansion-contraction shaft provided by an embodiment of the present invention when the expansion-contraction module expands outward.

Fig. 4 is a schematic diagram of an expansion-contraction module in an automatic expansion-contraction shaft provided by an embodiment of the present invention when the expansion-contraction module is contracted.

Fig. 5 is a schematic diagram of a fixed disk in an automatic expansion-contraction shaft provided by an embodiment of the present invention.

Fig. 6 is a schematic diagram of a left rotating disk in an automatic expansion and contraction shaft provided by an embodiment of the present invention.

FIG. 7 is a side view of FIG. 6 .

Fig. 8 is a schematic diagram of a right rotating disk in an automatic expansion and contraction shaft provided by an embodiment of the present invention.

FIG. 9 is a side view of FIG. 8 .

Fig. 10 is a schematic diagram of a sliding block in an automatic expansion-contraction shaft provided by an embodiment of the present invention.

Fig. 11 is a schematic diagram of clamping an upper mandrel in an automatic expansion-contraction shaft provided by an embodiment of the present invention.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

As shown in Figure 1-11, an automatic expansion and contraction shaft includes a support sleeve 11, a drive motor 16, a rotating shaft 15, and three shafts that are uniformly fixed in the supporting sleeve 11 along the axial direction and fixedly connected with the rotating shaft 15. The expansion-contraction module 17 , the driving motor 16 , the rotating shaft 15 and the expansion-contraction module 17 are all arranged in the support sleeve 11 .

As shown in FIG. 2 , scales 11 - 2 with scales are provided on both sides of the outer wall of the support sleeve 11 along the axial direction of the support sleeve 11 . The position of the mandrel 2 on the supporting sleeve 11 can be conveniently adjusted by the scale 11-2.

Both ends of the support sleeve 11 are provided with a support end cover 13 and a shaft head 12, the support sleeve 11 is provided with an internal thread, the support end cover 13 is provided with an external thread, and the support end cover 13 is threadedly connected with the support sleeve 11 The shaft head 12 is located outside the support end cover 13 and the outer wall of the shaft head 12 is fixed to the inner wall of the support sleeve 11 by welding. An external plug 19 is fixedly arranged in the central hole of one of the shaft heads 12 , and the external plug 19 is electrically connected to the drive motor 16 . The drive motor 16 can be started to work by energizing the external plug 19 .

The drive motor 16 is fixedly connected to the support end cover 13 on the same side as the shaft head 12 provided with the external plug 19, the output shaft of the drive motor 16 is fixedly connected to one end of the rotating shaft 15, and the axis of the rotating shaft 15 is connected to the axis of the supporting sleeve 11. In parallel, the other end of the rotating shaft 15 is rotatably arranged on the supporting end cap 13 on the other side, and rolling bearings 14 are arranged between the two supporting end caps 13 and the rotating shaft 15 .

As shown in Figure 1 and Figure 2, several groups of installation through-hole units 11-1 are evenly arranged on the outer wall of the support sleeve 11 along the axial direction, and each group of installation through-hole units 11-1 includes a number of uniformly arranged circumferentially. The through holes 11 - 1 - 1 are installed, and the number of groups of the through hole units 11 - 1 can be determined according to the length of the core barrel 2 . In this embodiment, three sets of installation through-hole units 11-1 are provided, and each set of installation through-hole units 11-1 is provided with four installation through-holes 11-1-1.

In this embodiment, four expansion-contraction modules 17 are provided, and each expansion-contraction module 17 corresponds to a group of installation through-hole units 11-1.

As shown in Figures 3, 4 and 5, each expansion-contraction module 17 includes a fixed disk 171, a left rotating disk 172, a right rotating disk 173 and a slider 174, and the outer peripheral wall of the fixed disk 171 is fixed to the inner wall of the support sleeve 11. Connection, both ends of the fixed disc 171 are concavely provided with a countersunk hole 171-1, and the central through hole 171-2 is provided in the fixed disc 171, the rotating shaft 15 passes through the central through hole 171-2, and the outer wall of the fixed disc 171 Four radial through-holes 171-3 opposite to the installation through-holes 11-1-1 are evenly arranged, and the fixed plate 171 is correspondingly provided with an axial direction communicating with each radial through-hole 171-3. Through grooves 171-4, each axial through groove 171-4 communicates with the central through hole 171-2, and the left rotating disk 172 and the right rotating disk 173 respectively rotate and sleeve in the counterbore holes 171-1 at both ends of the fixed disk 171 , and the left rotary disk 172 and the right rotary disk 173 are fixedly connected to the rotating shaft 15 .

As shown in Fig. 6 and Fig. 7, the left rotating disk 172 includes a first rotating disk base body 172-1 and a hollow first sleeve shaft 172-2, the outer diameter of the first rotating disk base body 172-1 is smaller than the diameter of the counterbore 171-1, the second A turntable base 172-1 is sleeved in the counterbore 171-1 and can rotate along with the rotating shaft through the first sleeve shaft 172-2. The center of the first turntable base 172-1 is provided with a first through hole 172-2- 1. Four first arc-shaped slots 172-3 are uniformly opened on the outer side of the first through hole 172-2-1 on the first turntable base 172-1, and the first arc-shaped slots 172-3 are inclined The arc-shaped slot, that is, the distance between the two ends of the first arc-shaped slot 172-3 and the center of the first turntable base 172-1 is different. One installation hole 172-2-2, the first sleeve shaft 172-2 is set concentrically with the first turntable base 172-1, one end of the first sleeve shaft 172-2 is fixedly connected with the first turntable base 172-1, the first set The shaft 172 - 2 is sheathed on the rotating shaft 15 and is fixedly connected to the rotating shaft 15 through a cylindrical pin 18 .

As shown in Fig. 8 and Fig. 9, the right rotating disk 173 includes a second rotating disk base body 173-1 and a hollow second sleeve shaft 173-2, the outer diameter of the second rotating disk base body 173-1 is smaller than the diameter of the counterbore 171-1, The second turntable base 173-1 is sleeved in the counterbore 171-1 and can rotate along with the rotating shaft through the second sleeve shaft 173-2. A second through hole 173-2 is opened in the center of the second turntable base 173-1. -1, four second arc-shaped slots 173-3 are uniformly opened in the outer circumference of the second through hole 173-2-1 on the second turntable base 173-1, and the second arc-shaped slots 173-3 are The inclined arc slot, the second arc slot 173-3 is opposite to the first arc slot 172-3, and the second sleeve shaft 173-2 is radially provided with a second installation for installing the cylindrical pin 18. Hole 173-2-2, the second sleeve shaft 173-2 is set concentrically with the first turntable base 172-1, one end of the second sleeve shaft 173-2 is fixedly connected with the second turntable base 173-1, the second sleeve shaft 173 -2 is sleeved on the rotating shaft 15 and fixedly connected with the rotating shaft 15 through a cylindrical pin 18.

A slide block 174 is arranged in each radial through hole 171-3, and the slide block 174 includes a movable block 174-1 slidably arranged in the radial through hole 171-3 and relatively fixedly arranged on both sides of the movable block 174-1. The two guide shafts 174-2 and the movable block 174-1 can extend out of the support sleeve 11 through the radial through hole 171-3 and the corresponding installation through hole 11-1-1 and abut against the core barrel 2, and the two The guide shafts 174-2 are fixed in the opposite first arc-shaped slots 172-3 and the second arc-shaped slots 173-3 respectively and can move in the corresponding axial through slots 171-4.

The driving motor 16 rotates forward, and the output shaft of the driving motor 16 drives the rotating shaft 15 to rotate clockwise, thereby driving each expansion-contraction module 17 fixedly connected with the rotation shaft 15 to rotate clockwise, specifically driving the left-hand rotary disk 172 and the right-hand rotation disk 172 in the expansion-contraction module 17. The turntable 173 rotates, thereby driving the two guide shafts 174-2 clamped in the first arc-shaped slot 172-3 and the second arc-shaped slot 173-3 toward the center of the fixed disc 171 in the axial through slot 171-4. direction, and then drive the movable block 174-1 to move into the fixed plate in the radial through hole 171-3 until it retracts into the radial through hole 171-3. At this time, the expansion and contraction module is in the shrinking state, as shown 4, the two guide shafts 174-2 on the slider 174 are respectively located in the opposite first arc-shaped slot 172-3 and the second arc-shaped slot 173-3 away from the first turntable base 172-1 and the second arc-shaped slot 172-1. On the closest position at the center of the two turntable base bodies 173-1.

The driving motor 16 is reversed, and the output shaft of the driving motor 16 drives the rotating shaft 15 to rotate counterclockwise, thereby driving the left rotary disk 172 and the right rotary disk 173 in the expansion-contraction module 17 to rotate, thereby driving the card in the first arc-shaped slot 172-3 and the two guide shafts 174-2 in the second arc-shaped slot 173-3 move away from the center of the fixed disk 171 in the axial through groove 171-4, and then drive the movable block 174-1 in the radial through hole 171-3 Move from the inside to the outside of the fixed plate, so that the movable block 174-1 protrudes from the corresponding installation through hole 11-1-1 and abuts on the core tube 2 to clamp the core tube. At this time, the expansion and contraction module is in the external expansion state, as shown in Figure 3, the two guide shafts 174-2 on the slider 174 are respectively located in the opposite first arc-shaped slot 172-3 and the second arc-shaped slot 173-3 away from the first turntable base 172 -1 and the farthest position at the center of the second turntable base 173-1.

The slide block 174 also includes a clamping block 175, one end of the clamping block 175 is fixedly connected with the movable block 174-1 by bolts, the other end of the clamping block 175 is arc-shaped, and the radian is consistent with that of the outer surface of the fixed plate, and the clamping block The other end of 175 is evenly concaved with a number of grooves 175-1, and the other end of the block 175 can extend out of the support sleeve 11 from the installation through-hole unit 11-1 along with the movable block 174-1 and abut against the coil. Cartridge 2 on. When the expansion-contraction module is in the retracted state, one end of the block 175 with the groove 175-1 is located on the same surface as the outer surface of the fixed plate. Setting the block 175 and opening the groove 175-1 on it can enhance the friction and prevent slipping, so that the clamping core can be more firmly. There is a detachable connection between the clamping block 175 and the movable block 174-1, and when one of them wears out and affects its use, only the damaged one needs to be replaced. In another embodiment, the locking block 175 is not provided, but a groove is recessed at one end of the movable block 174-1, and the end of the movable block 174-1 with the groove can be installed from the through hole unit 11- 1 protrudes from the support sleeve 11 and abuts against the mandrel 2.

when using it:

(1) Before putting the core barrel 2 on the support sleeve 11, first check whether the block 175 is retracted along with the movable block 174-1. The power supply makes the driving motor 16 work, the driving motor 16 rotates forward, and the output shaft of the driving motor 16 drives the rotating shaft 15 to rotate, thereby driving the left rotating disk 172 and the right rotating disk 173 in the expansion and contraction module 17 to rotate simultaneously, and then driving the two guides in the slider 174 The shaft 174-2 moves toward the center of the fixed disk 171 in the axial through groove 171-4, thereby driving the movable block 174-1 and the locking block 175 to move into the fixed disk 171, and adjusting the expansion-contraction module 17 to the retracted state.

(2) Then disconnect the external plug 19, stop the power supply of the drive motor 16, put the core tube 2 on the supporting sleeve 11, and connect with the winding and unwinding equipment through the shaft heads 12 at both ends of the supporting sleeve 11.

(3) Adjust the core tube 2 to the middle position of the support sleeve 11 according to the left and right positions of the core tube 2 on the support sleeve 11 indicated by the scale 11-2, as shown in FIG. 11 .

(4) Connect the external plug 19 to power off the drive motor 16, and the drive motor 16 reverses, thereby driving the left rotary disk 172 and the right rotary disk 173 in the expansion and contraction module 17 to rotate simultaneously, and then driving the two guide shafts 174-174 in the slider 174 2 Move away from the center of the fixed disk 171 in the axial through groove 171-4, thereby driving the movable block 174-1 and the clamping block 175 to move to the outside of the fixed disk 171 until the clamping block 175 moves from the radial through hole 171-3, The installation through hole 11 - 1 - 1 protrudes and abuts against the core barrel 2 to complete the automatic clamping of the core barrel 2 .

The parts not involved in the present invention are the same as the prior art or implemented by adopting the prior art.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Those skilled in the art can make various equivalent changes and improvements on the basis of the above-mentioned embodiments, and all equivalent changes and modifications made within the scope of the claims shall fall within the protection scope of the present invention.

Claims (7)

1. An automatic expansion and contraction shaft, characterized in that: it includes a support sleeve (11), a drive motor (16), a rotating shaft (15) and is fixedly arranged in the support sleeve (11) and is fixedly connected with the rotating shaft (15). Several expansion-contraction modules (17), drive motors (16), rotating shafts (15) and expansion-contraction modules (17) are all arranged in the support sleeve (11), The outer wall of the support sleeve (11) is provided with several groups of installation through-hole units (11-1) equal in number to the expansion-contraction modules (17) along the axial direction, and each group of installation through-hole units (11-1) includes Several installation through holes (11-1-1) arranged in the circumferential direction, The drive motor (16) is fixedly arranged on one side in the support sleeve (11), the axis of the rotating shaft (15) is parallel to the axis of the support sleeve (11), and one end of the rotating shaft (15) is connected to the drive motor (16) output shaft connection, Several expansion-contraction modules (17) are set in one-to-one correspondence with several groups of installation through-hole units (11-1), Each expansion-contraction module (17) comprises a fixed disc (171), a left rotary disc (172), a right rotary disc (173) and a slide block (174), The outer peripheral wall of the fixed plate (171) is fixedly connected with the inner wall of the support sleeve (11), and a countersunk hole (171-1) is provided on both ends of the fixed plate (171), and a central through hole (171-1) is provided in the fixed plate (171). Holes (171-2), the outer wall of the fixed plate (171) are circumferentially provided with several radial through holes ( 171-3), and on the fixed plate (171), there are corresponding axial through grooves (171-4) communicating with each radial through hole (171-3), the left rotary plate (172) and the right rotary plate (173) rotate respectively in the counterbore (171-1) that is sleeved at the two ends of the fixed disk (171), and the left rotating disk (172) and the right rotating disk (173) are all fixedly connected with the rotating shaft (15), and the left rotating disk ( 172) and the right rotating disk (173) are relatively evenly provided with the first arc-shaped slot (172-3) and the second arc-shaped slot (172-3) and the second arc-shaped slot ( 173-3), each radial through hole (171-3) is provided with a slide block (174), and the slide block (174) includes a movable block (174) slidingly arranged in the radial through hole (171-3). -1) and two guide shafts (174-2) that are relatively fixed on both sides of the movable block (174-1), the movable block (174-1) can pass through the radial through hole (171-3) and the corresponding installation through The hole unit (11-1) protrudes from the support sleeve (11), and the two guide shafts (174-2) are respectively clamped in the opposite first arc-shaped slot (172-3) and the second arc-shaped slot ( 173-3) and can move in the corresponding axial through groove (171-4). 2. An automatic expansion and contraction shaft according to claim 1, characterized in that: both ends of the support sleeve (11) are provided with a support end cover (13) and a shaft head (12), and the support end cover (13 ) is threadedly connected with the support sleeve (11), the drive motor (16) is fixedly connected with the support end cover (13), the shaft head (12) is located on the outside of the support end cover (13) and is fixed to the inner wall of the support sleeve (11) connect. 3. An automatic expansion and contraction shaft according to claim 2, characterized in that: it also includes an external plug (19), the external plug (19) is fixedly arranged in the center hole of the shaft head (12), and the external plug (19) is electrically connected with the drive motor (16). 4. An automatic expansion and contraction shaft according to claim 1, characterized in that: a scale (11-2) is provided on the outer wall of the support sleeve (11) along the axial direction of the support sleeve (11). 5. An automatic expansion and contraction shaft according to claim 1, characterized in that: the left rotating disk (172) comprises a first rotating disk base (172-1) and a hollow first sleeve shaft (172-2), the first The turntable base (172-1) is uniformly provided with first arc-shaped slots (172-3) in the circumferential direction equal in number to the axial through slots (171-4) and arranged obliquely. A first through hole (172-2-1) is opened at the center of the first turntable base (172-1), and the first sleeve shaft (172-2) is concentrically arranged with the first turntable base (172-1). One end of the shaft (172-2) is fixedly connected to the first turntable base (172-1), and the first sleeve shaft (172-2) is sleeved on the rotating shaft (15) and fixedly connected to the rotating shaft (15). 6. An automatic expansion and contraction shaft according to claim 1, characterized in that: the right rotating disc (173) comprises a second rotating disc base (173-1) and a hollow second sleeve shaft (173-2), the second The second turntable base (173-1) is evenly provided with second arc-shaped slots (173-3) in the circumferential direction equal to the number of axial through slots (171-4) and arranged obliquely, A second through hole (173-2-1) is opened at the center of the second turntable base (173-1), and the second sleeve shaft (173-2) is concentrically arranged with the first turntable base (172-1). One end of the shaft (173-2) is fixedly connected with the second turntable base (173-1), and the second sleeve shaft (173-2) is sleeved on the rotating shaft (15) and fixedly connected with the rotating shaft (15). 7. An automatic expansion and contraction shaft according to claim 1, characterized in that: the slider (174) also includes a block (175), one end of the block (175) and the movable block (174-1) can be Disassemble the connection, the other end of the block (175) is concaved with several grooves (175-1), and the other end of the block (175) can be installed from the through hole unit (11) along with the movable block (174-1). Extend the support sleeve (11) in -1).