CN116423251A

CN116423251A - Positioning tool for numerical control machine tool

Info

Publication number: CN116423251A
Application number: CN202310501544.5A
Authority: CN
Inventors: 赵冬冬; 杨玉霞; 蒋晓; 靳峰峰; 曹生亮; 郑标帝
Original assignee: Jiyuan Vocational and Technical College
Current assignee: Jiyuan Vocational and Technical College
Priority date: 2023-05-05
Filing date: 2023-05-05
Publication date: 2023-07-14

Abstract

The invention discloses a positioning tool for a numerical control machine tool, which comprises the following components: the first installation sleeve is connected with the second installation sleeve in a sliding manner, and the connecting block is installed at the bottom end of the first installation sleeve; the deformation rod mechanism comprises a first sliding rod which is connected in the second installation sleeve in a sliding way, a deformation rod assembly is arranged on the first sliding rod, and the deformation rod assembly is hinged with the end part of the second installation sleeve and the first sliding rod; the positioning mechanism comprises a telescopic component arranged at the top end of the deformation rod component, one end of the telescopic component is fixedly connected with a mounting frame, a distance changing component is arranged on the mounting frame, and a plurality of positioning components are arranged on the distance changing component; the contraction mechanism is arranged in the first installation sleeve, and the first installation sleeve and the second installation sleeve and the first sliding rod are respectively in sliding fit through the contraction mechanism. The invention can position different parts of workpieces with different shapes, and improves the application range of the device.

Description

Positioning tool for numerical control machine tool

Technical Field

The invention relates to the field of machine tool positioning, in particular to a positioning tool for a numerical control machine tool.

Background

The numerical control machine tool is short for numerical control machine tool, and is an automatic machine tool with a program control system. The control system is able to logically process a program defined by control codes or other symbolic instructions, and to decode it, expressed in coded numbers, and input to the numerical control device via the information carrier. The numerical control device sends out various control signals through operation processing to control the action of the machine tool, parts are automatically machined according to the shape and the size required by a drawing, the numerical control machine tool well solves the problems of machining complex, precise, small-batch and multiple types of parts, is a flexible and high-efficiency automatic machine tool, represents the development direction of the control technology of the modern machine tool, and is a typical electromechanical integrated product.

When a numerical control machine tool processes a workpiece, a waist-shaped groove is formed in the middle of a positioning block mainly through a strip-shaped positioning block, the waist-shaped groove is fixedly connected with a T-shaped block on a processing platform of the machine tool through a bolt, the positioning is simple, but the multi-angle positioning of an irregular part cannot be realized, and therefore a positioning tool capable of positioning the irregular part at multiple angles is needed.

Disclosure of Invention

The invention aims to provide a positioning tool for a numerical control machine tool, which solves the problems existing in the prior art.

In order to achieve the above object, the present invention provides the following solutions: the invention provides a positioning tool for a numerical control machine tool, which comprises:

the first mounting sleeve is connected with the second mounting sleeve in a sliding manner, and the connecting block is mounted at the bottom end of the first mounting sleeve;

the deformation rod mechanisms are provided with a plurality of groups, the groups of deformation rod mechanisms are circumferentially arranged at one end of the second installation sleeve at intervals, each deformation rod mechanism comprises a first sliding rod which is slidably connected in the second installation sleeve, a deformation rod assembly is arranged on each first sliding rod, and each deformation rod assembly is hinged with the end part of the second installation sleeve and the first sliding rod;

the positioning mechanism is provided with a plurality of groups, the plurality of groups of positioning mechanisms are respectively arranged at the working ends of the deformation rod assemblies, the positioning mechanism comprises a telescopic assembly arranged at the top ends of the deformation rod assemblies, one end of the telescopic assembly is fixedly connected with a mounting frame, a distance changing assembly is arranged on the mounting frame, and a plurality of positioning assemblies are arranged on the distance changing assembly;

the contraction mechanism is arranged in the first installation sleeve, and the first installation sleeve is in sliding fit with the second installation sleeve and the second installation sleeve is in sliding fit with the first sliding rod through the contraction mechanism.

According to the positioning tool for the numerical control machine tool, the deformation rod assembly comprises the hinging rod hinged to the end part of the second mounting sleeve, the first telescopic rod is hinged to the middle part of the hinging rod, one end, away from the hinging rod, of the first telescopic rod is hinged to the first sliding rod, an included angle between the axis of the first telescopic rod and the axis of the first sliding rod is an obtuse angle, one end, hinged to the first sliding rod, of the second telescopic rod is an acute angle, and one end, away from the second mounting sleeve, of the hinging rod is hinged to the telescopic assembly, and one end, away from the first sliding rod, of the second telescopic rod is hinged to the bottom end of the mounting frame.

According to the positioning tool for the numerical control machine tool, the distance changing assembly comprises the distance changing rod which is rotatably connected to the mounting frame, a plurality of spiral grooves are formed in the distance changing rod at equal intervals, the distance changing rod is connected with the sliding block in a sliding mode, the inner wall of the sliding block is fixedly connected with the guide block, the guide block is connected in the spiral grooves in a sliding mode, one end of the mounting frame is fixedly connected with the first motor, an output shaft of the first motor is connected with one end of the distance changing rod in a shaft mode, and the positioning assembly is hinged with the sliding block through the universal joint.

According to the positioning tool for the numerical control machine tool, the positioning assembly comprises the mounting block, the mounting block is hinged with the sliding block through the universal joint, a groove is formed in one side, away from the universal joint, of the mounting block, a positioning ball is rotatably connected in the groove, a plane is arranged on the positioning ball, and the plane on the positioning ball is located outside the groove.

According to the positioning tool for the numerical control machine tool, the telescopic component comprises the supporting block, the top end of the hinging rod is hinged with the side face of the supporting block, the supporting block is provided with the through hole, the through hole is internally and slidably connected with the second sliding rod, one end of the second sliding rod is fixedly connected with the middle of the side face of the mounting frame, the first spring is arranged between the supporting block and the mounting frame, and the first spring is sleeved on the second sliding rod.

According to the positioning tool for the numerical control machine tool, the contraction mechanism comprises two mounting shafts which are rotatably connected in the first mounting sleeve, the two mounting shafts are arranged in parallel, the axes of the two mounting shafts are positioned in the same vertical plane, a through groove is formed in one end of the second mounting sleeve positioned in the first mounting sleeve along the horizontal direction, the mounting shaft positioned below is in sliding fit with the through groove, driving assemblies are respectively arranged on the two mounting shafts, the two driving assemblies are respectively in transmission fit with the first sliding rod and the second mounting sleeve, and the driving assemblies on the two mounting shafts are in transmission fit; the first installation sleeve is internally and fixedly connected with a second motor, and an output shaft of the second motor is coaxially and fixedly connected with the installation shaft positioned above.

According to the positioning tool for the numerical control machine tool, the driving assembly comprises the telescopic gear mechanism and the chain wheels which are rotatably connected to the mounting shafts, and the chain wheels on the two mounting shafts are in transmission connection through the chain;

and the top end of the second installation sleeve is provided with a yielding groove, and the chain extends into the second installation sleeve through the yielding groove to be in transmission fit with the two chain wheels.

According to the positioning tool for the numerical control machine tool, the telescopic gear mechanism comprises an annular block, the mounting shaft comprises a first connecting shaft and a second connecting shaft, one end of the first connecting shaft is rotationally connected with the inner wall of the first mounting sleeve, the other end of the first connecting shaft is fixedly connected with one end of a third telescopic rod, one end of the second connecting shaft, which is far away from the first mounting sleeve, is coaxially and slidably connected with the output shaft of the third telescopic rod, the annular block is sleeved on the output shaft of the third telescopic rod, the annular block is rotationally clamped with the second connecting shaft, an annular groove is formed in the inner wall of the annular block, an extrusion block is slidably connected with the annular groove in a sliding manner, a plurality of long holes are formed in the outer wall of the annular block at equal intervals in a circumferential direction, the long holes are communicated with the annular groove, a telescopic tooth assembly is mounted in the long holes, and one end of the telescopic tooth assembly is abutted against the extrusion block.

According to the positioning tool for the numerical control machine tool, the telescopic tooth assembly comprises the third sliding rod which is connected in the long hole in a sliding mode, one end of the third sliding rod, which is located in the annular groove, is fixedly connected with a wedge block, the cross section of the wedge block is in a right trapezoid shape, the inclined surface of the wedge block is abutted to the extrusion block, the other end of the third sliding rod is fixedly connected with a tooth, a second spring is sleeved on the third sliding rod, one end of the second spring is fixedly connected with the long hole, the other end of the second spring is fixedly connected with the third sliding rod, tooth grooves are respectively formed in the outer wall of the second installation sleeve and the outer wall of the first sliding rod, and the tooth grooves are matched with the tooth grooves.

According to the positioning tool for the numerical control machine tool, the limiting seat is fixedly connected in the second mounting sleeve, and the first sliding rod is connected to the limiting seat in a sliding mode.

The invention discloses the following technical effects:

when the device is used, the connecting block is fixed with the strip-shaped positioning block of the machine tool, the contraction mechanism is used for adjusting the relative position of the second mounting sleeve, then the contraction mechanism is used for adjusting the relative position of the first sliding rod again, the first sliding rod is used for controlling the deformation rod assembly to change in angle, so that the expansion assembly and the displacement assembly are controlled to change in angle, and then the positioning mechanism is used for realizing positioning.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic structural view of a positioning tool for a numerical control machine tool;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is a schematic view of the mating relationship between the mounting bracket and the distance-varying rod according to the present invention;

FIG. 4 is a schematic view of the retraction mechanism of the present invention;

fig. 5 is a schematic structural view of the telescopic gear mechanism of the present invention.

1, a first mounting sleeve; 2. a second mounting sleeve; 3. a first slide bar; 4. a mounting frame; 5. a hinge rod; 6. a first telescopic rod; 7. a second telescopic rod; 8. a pitch-variable lever; 9. a spiral groove; 10. a slide block; 11. a guide block; 12. a first motor; 13. a mounting block; 14. a universal joint; 15. a positioning ball; 16. a support block; 17. a second slide bar; 18. a first spring; 19. a second motor; 20. a sprocket; 21. a chain; 22. a long hole; 23. a first connecting shaft; 24. a second connecting shaft; 25. a third telescopic rod; 26. an annular block; 27. a third slide bar; 28. wedge blocks; 29. teeth; 30. a second spring; 31. and a limiting seat.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Referring to fig. 1 to 4, the present invention provides a positioning tool for a numerical control machine tool, comprising:

the first installation sleeve 1 is connected with the second installation sleeve 2 in a sliding way, and a connecting block is arranged at the bottom end of the first installation sleeve 1;

the deformation rod mechanisms are provided with a plurality of groups, the groups of deformation rod mechanisms are circumferentially arranged at one end of the second installation sleeve 2 at intervals, each deformation rod mechanism comprises a first sliding rod 3 which is slidably connected in the second installation sleeve 2, a deformation rod assembly is arranged on the first sliding rod 3, and the deformation rod assembly is hinged with the end part of the second installation sleeve 2 and the first sliding rod 3;

the positioning mechanism is provided with a plurality of groups, the plurality of groups of positioning mechanisms are respectively arranged at the working ends of the deformation rod assemblies, the positioning mechanism comprises a telescopic assembly arranged at the top ends of the deformation rod assemblies, one end of the telescopic assembly is fixedly connected with a mounting frame 4, a distance changing assembly is arranged on the mounting frame 4, and a plurality of positioning assemblies are arranged on the distance changing assembly;

the contraction mechanism is arranged in the first installation sleeve 1, and the first installation sleeve 1 and the second installation sleeve 2 and the first sliding rod 3 are respectively in sliding fit through the contraction mechanism.

When the device is used, the connecting block is fixed with a strip-shaped positioning block of a machine tool, the relative position of the second mounting sleeve 2 is adjusted by the contraction mechanism, then the relative position of the first sliding rod 3 is adjusted by the contraction mechanism again, the deformation rod assembly is controlled to change in angle by the first sliding rod 3, so that the expansion assembly and the distance changing assembly are controlled to change in angle, and then the positioning is realized by the positioning mechanism.

Further optimizing scheme, deformation pole subassembly is including articulating the articulated pole 5 at the 2 tip of second installation cover, articulated the first telescopic link 6 that has in the middle part of articulated pole 5, the one end that articulated pole 5 was kept away from to first telescopic link 6 is articulated with first slide bar 3, the contained angle between the axis of first telescopic link 6 and the axis of first slide bar 3 is the obtuse angle, articulated the one end that has second telescopic link 7 on the first slide bar 3, the contained angle between the axis of second telescopic link 7 and the axis of first slide bar 3 is the acute angle, the one end that articulated pole 5 was kept away from second installation cover 2 is articulated with telescopic component, the one end that second telescopic link 7 was kept away from first slide bar 3 is articulated with the bottom of mounting bracket 4.

The setting of deformation pole subassembly can be convenient for adjust positioning component's relative position and angle, through the angle of first telescopic link 6 and the control positioning component of second telescopic link 7.

Further optimizing scheme, the displacement subassembly is including rotating the displacement pole 8 of connection on mounting bracket 4, equidistant a plurality of helicla flute 9 of having seted up on the displacement pole 8, sliding connection has slider 10 on the displacement pole 8, slider 10 inner wall fixedly connected with guide block 11, guide block 11 sliding connection is in helicla flute 9, mounting bracket 4 one end fixedly connected with first motor 12, the output shaft of first motor 12 and the one end coupling of displacement pole 8, positioning component passes through the universal joint and articulates with slider 10. The variable-pitch assembly is matched with the positioning assembly to position different positions of workpieces in different shapes. The first motor 12 drives the variable-pitch rod 8 to rotate, and the guide block 11 and the spiral groove 9 are matched to enable the sliding block 10 to move on the variable-pitch rod 8 along the axis direction, so that variable-pitch adjustment is realized.

Further optimizing scheme, locating component includes installation piece 13, articulates through universal joint 14 between installation piece 13 and the slider 10, and the installation piece 13 is kept away from the one side of universal joint and is seted up flutedly, and the recess internal rotation is connected with location ball 15, is provided with the plane on the location ball 15, and the plane on the location ball 15 is located outside the recess. By positioning the positioning ball 15, different positions of workpieces with different shapes can be positioned.

Further optimizing scheme, the flexible subassembly includes supporting shoe 16, and the top of articulated pole 5 is articulated with the side of supporting shoe 16, has offered the through-hole on the supporting shoe 16, and sliding connection has second slide bar 17 in the through-hole, and the middle part fixed connection of the one end of second slide bar 17 and mounting bracket 4 side is provided with first spring 18 between supporting shoe 16 and the mounting bracket 4, and first spring 18 cover is established on second slide bar 17.

According to a further optimization scheme, the shrinkage mechanism comprises two mounting shafts which are rotatably connected in the first mounting sleeve 1, the two mounting shafts are arranged in parallel, the axes of the two mounting shafts are positioned in the same vertical plane, a through groove is formed in one end of the second mounting sleeve 2 positioned in the first mounting sleeve 1 along the horizontal direction, the mounting shafts positioned below are in sliding fit with the through groove, driving assemblies are respectively arranged on the two mounting shafts and are respectively in transmission fit with the first sliding rod 3 and the second mounting sleeve 2, and the driving assemblies on the two mounting shafts are in transmission fit; the first installation sleeve 1 is internally and fixedly connected with a second motor 19, and an output shaft of the second motor 19 is coaxially and fixedly connected with an installation shaft positioned above.

In a further optimized scheme, the driving assembly comprises a telescopic gear mechanism and a chain wheel 20 which are rotatably connected to the mounting shafts, and the chain wheels 20 on the two mounting shafts are in transmission connection through a chain 21;

the top of the second installation sleeve 2 is provided with a yielding groove, and the chain 21 extends into the second installation sleeve 2 through the yielding groove to be in transmission fit with the two chain wheels 20.

The second motor 19 drives one of the installation shafts to rotate so as to drive the chain wheel 20 on the installation shaft to rotate, the chain wheel 20 drives the other chain wheel 20 to rotate through the chain 21, so that two telescopic gear mechanisms rotate, when the second installation sleeve 2 needs to stretch out, the telescopic gear mechanism positioned outside the second installation shaft stretches out and is meshed with a tooth slot on the outer wall of the second installation sleeve 2 to drive the second installation sleeve 2 to slide, and at the moment, the position of the first sliding rod 3 correspondingly changes, so that the second motor 19 selects a motor capable of rotating positively and negatively, and the relative positions of the second installation sleeve 2 and the first sliding rod 3 are adjusted.

Further optimizing scheme, flexible gear mechanism includes annular piece 26, the installation axle includes first connecting axle 23 and second connecting axle 24, first connecting axle 23 one end rotates with the inner wall of first installation cover 1 to be connected, the one end of the third telescopic link 25 of the other end fixedly connected with, the one end that first installation cover 1 was kept away from to second connecting axle 24 and the coaxial sliding connection of the output shaft of third telescopic link 25, annular piece 26 cover is established on the output shaft of third telescopic link 25, and rotate the joint between annular piece 26 and the second connecting axle 24, the annular groove has been seted up on the inner wall of annular piece 26, sliding connection has the extrusion piece in the annular groove, extrusion piece sliding connection is on second connecting axle 24 and with the output shaft rigid coupling of third telescopic link 25, a plurality of slot holes 22 have been seted up to the outer wall circumference equidistant of annular piece 26, slot hole 22 and annular groove intercommunication, install flexible tooth subassembly in the slot hole 22, flexible tooth subassembly one end and extrusion piece butt.

Further optimizing scheme, flexible tooth subassembly includes sliding connection's third slide bar 27 in slot hole 22, the one end fixedly connected with voussoir 28 that third slide bar 27 is located the ring channel, the cross-sectional shape of voussoir 28 is right trapezoid, the inclined plane and the extrusion piece butt of voussoir 28, third slide bar 27 other end fixedly connected with tooth 29, the cover is equipped with second spring 30 on the third slide bar 27, second spring 30 one end and slot hole 22 fixed connection, second spring 30's the other end and third slide bar 27 fixed connection, the tooth's socket has been seted up respectively to the outer wall of second installation cover 2, the outer wall of first slide bar 3, tooth 29 and tooth's socket looks adaptation.

The telescopic gear mechanism is arranged so that only one driving device is needed to control the first sliding rod 3 or the second mounting sleeve 2 to slide at will, thereby controlling the extension or retraction of the first sliding rod 3 or the second mounting sleeve 2.

When the teeth 29 are needed to be meshed with the tooth grooves, the extrusion block is controlled to slide through the third telescopic rod 25, the wedge block 28 is extruded to slide upwards through the extrusion block, the wedge block 28 pushes the teeth 29 to extend out through the third sliding rod 27 to be meshed with the tooth grooves, meanwhile, a compression effect is generated on the second springs 30, when the teeth 29 are not needed to be meshed with the tooth grooves, the third telescopic rod 25 pushes the extrusion block to move, the extrusion effect on the wedge block 28 is relieved, and the third sliding rod 27 drives the teeth 29 to retract under the action of the second springs 30.

The bearing is arranged between the second connecting shaft 24 and the annular block 26, the bearing inner ring is fixedly connected with the second connecting shaft 24, the bearing outer ring is fixedly connected with the inner wall of the annular block 26, and therefore only a rotation relationship exists between the second connecting shaft 24 and the annular block 26, and the output shaft of the third telescopic rod 25 and the inner wall of the annular block 26 can rotate and/or slide.

According to the further optimization scheme, a limiting seat 31 is fixedly connected in the second installation sleeve 2, and the first sliding rod 3 is connected to the limiting seat 31 in a sliding mode. The sliding position of the first sliding rod 3 is limited by the limiting seat 31, so that the first sliding rod 3 is ensured to be in a horizontal sliding state.

In the description of the present invention, it should be understood that the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present invention, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.

Claims

1. Positioning tool for digit control machine tool, its characterized in that includes:

the first mounting sleeve (1) is connected with the second mounting sleeve (2) in a sliding manner, and a connecting block is arranged at the bottom end of the first mounting sleeve (1);

the deformation rod mechanisms are provided with a plurality of groups, the groups of the deformation rod mechanisms are circumferentially arranged at one end of the second installation sleeve (2) at intervals, each deformation rod mechanism comprises a first sliding rod (3) which is slidably connected in the second installation sleeve (2), a deformation rod assembly is arranged on each first sliding rod (3), and each deformation rod assembly is hinged with the end part of the corresponding second installation sleeve (2) and the corresponding first sliding rod (3);

the positioning mechanism is provided with a plurality of groups, the plurality of groups of positioning mechanisms are respectively arranged at the working ends of the deformation rod assemblies, the positioning mechanism comprises a telescopic assembly arranged at the top ends of the deformation rod assemblies, one end of the telescopic assembly is fixedly connected with a mounting frame (4), a distance changing assembly is arranged on the mounting frame (4), and a plurality of positioning assemblies are arranged on the distance changing assembly;

the shrinkage mechanism is arranged in the first installation sleeve (1), and the first installation sleeve (1) is in sliding fit with the second installation sleeve (2) and the second installation sleeve (2) is in sliding fit with the first sliding rod (3) through the shrinkage mechanism.

2. The positioning tool for a numerical control machine tool according to claim 1, wherein: the deformation rod assembly comprises a hinge rod (5) hinged to the end portion of the second installation sleeve (2), a first telescopic rod (6) is hinged to the middle portion of the hinge rod (5), one end of the hinge rod (5) is hinged to the first sliding rod (3) in a manner that the first telescopic rod (6) is far away, an included angle between the axis of the first telescopic rod (6) and the axis of the first sliding rod (3) is an obtuse angle, one end of a second telescopic rod (7) is hinged to the first sliding rod (3), an included angle between the axis of the second telescopic rod (7) and the axis of the first sliding rod (3) is an acute angle, one end of the second installation sleeve (2) is far away from the hinge rod (5) and the telescopic assembly are hinged, and one end of the first sliding rod (3) is far away from the second telescopic rod (7) and the bottom of the installation frame (4) is hinged.

3. The positioning tool for a numerical control machine tool according to claim 2, wherein: the pitch-changing assembly comprises a pitch-changing rod (8) which is rotationally connected to a mounting frame (4), a plurality of spiral grooves (9) are formed in the pitch-changing rod (8) at equal intervals, a sliding block (10) is connected to the pitch-changing rod (8) in a sliding mode, a guide block (11) is fixedly connected to the inner wall of the sliding block (10), the guide block (11) is connected to the spiral groove (9) in a sliding mode, a first motor (12) is fixedly connected to one end of the mounting frame (4), an output shaft of the first motor (12) is connected with one end of the pitch-changing rod (8) in a shaft mode, and the positioning assembly is hinged to the sliding block (10) through a universal joint.

4. A positioning tool for a numerical control machine tool according to claim 3, wherein: the positioning assembly comprises a mounting block (13), the mounting block (13) is hinged to the sliding block (10) through a universal joint (14), a groove is formed in one side, away from the universal joint, of the mounting block (13), a positioning ball (15) is rotatably connected in the groove, a plane is arranged on the positioning ball (15), and the plane on the positioning ball (15) is located outside the groove.

5. The positioning tool for a numerical control machine tool according to claim 2, wherein: the telescopic assembly comprises a supporting block (16), the top end of a hinge rod (5) is hinged to the side face of the supporting block (16), a through hole is formed in the supporting block (16), a second sliding rod (17) is connected in the through hole in a sliding mode, one end of the second sliding rod (17) is fixedly connected with the middle portion of the side face of the mounting frame (4), a first spring (18) is arranged between the supporting block (16) and the mounting frame (4), and the first spring (18) is sleeved on the second sliding rod (17).

6. The positioning tool for a numerical control machine tool according to claim 1, wherein: the shrinkage mechanism comprises two mounting shafts which are rotationally connected in the first mounting sleeve (1), the two mounting shafts are arranged in parallel, the axes of the two mounting shafts are positioned in the same vertical plane, a through groove is formed in one end of the second mounting sleeve (2) positioned in the first mounting sleeve (1) along the horizontal direction, the mounting shaft positioned below is in sliding fit with the through groove, driving assemblies are respectively mounted on the two mounting shafts, the two driving assemblies are respectively in transmission fit with the first sliding rod (3) and the second mounting sleeve (2), and the driving assemblies on the two mounting shafts are in transmission fit; the first installation sleeve (1) is internally and fixedly connected with a second motor (19), and an output shaft of the second motor (19) is coaxially and fixedly connected with the installation shaft positioned above.

7. The positioning tool for a numerical control machine tool according to claim 6, wherein: the driving assembly comprises a telescopic gear mechanism and a chain wheel (20) which are rotatably connected to the mounting shafts, and the chain wheels (20) on the two mounting shafts are in transmission connection through a chain (21);

and the top end of the second installation sleeve (2) is provided with a yielding groove, and the chain (21) extends into the second installation sleeve (2) through the yielding groove to be in transmission fit with the two chain wheels (20).

8. The positioning tool for a numerical control machine tool according to claim 7, wherein: the telescopic gear mechanism comprises an annular block (26), the mounting shaft comprises a first connecting shaft (23) and a second connecting shaft (24), one end of the first connecting shaft (23) is rotationally connected with the inner wall of the first mounting sleeve (1), one end of a third telescopic rod (25) is fixedly connected with the other end of the first connecting shaft, the second connecting shaft (24) is away from one end of the first mounting sleeve (1) and the output shaft of the third telescopic rod (25) are coaxially and slidably connected, the annular block (26) is sleeved on the output shaft of the third telescopic rod (25), the annular block (26) is rotationally clamped with the second connecting shaft (24), an annular groove is formed in the inner wall of the annular block (26), an extrusion block is slidably connected with the output shaft of the third telescopic rod (25), a plurality of long holes (22) are formed in the outer wall of the annular block (26) at equal intervals, the long holes (22) are communicated with the annular groove (22), and one end of the annular block is in a telescopic assembly, and the telescopic assembly is in a telescopic joint.

9. The positioning tool for a numerical control machine tool according to claim 8, wherein: the telescopic tooth assembly comprises a third sliding rod (27) which is slidably connected in the long hole (22), one end of the third sliding rod (27) is fixedly connected with a wedge block (28) which is located in the annular groove, the cross section of the wedge block (28) is right trapezoid, the inclined surface of the wedge block (28) is in butt joint with the extrusion block, the other end of the third sliding rod (27) is fixedly connected with a tooth (29), a second spring (30) is sleeved on the third sliding rod (27), one end of the second spring (30) is fixedly connected with the long hole (22), the other end of the second spring (30) is fixedly connected with the third sliding rod (27), tooth grooves are respectively formed in the outer wall of the second installation sleeve (2) and the outer wall of the first sliding rod (3), and the tooth teeth (29) are matched with the tooth grooves.

10. The positioning tool for a numerical control machine tool according to claim 1, wherein: the second installation sleeve (2) is internally and fixedly connected with a limiting seat (31), and the first sliding rod (3) is in sliding connection with the limiting seat (31).