阅读说明：本技术 车床用工件快换工装 (Workpiece quick-change tool for lathe ) 是由 戚晓楠 孙先海 赵光裕 陈然 赵俊杰 董方昱 胡浩 闫泽旺 娄郑君 高振 于 2020-07-07 设计创作，主要内容包括：本发明涉及车床用工件快换工装。车床用工件快换工装包括：筒夹夹具、主轴连接座和夹头拉爪,筒夹夹具包括筒夹夹头和筒夹螺母,筒夹螺母螺纹连接在筒夹夹头的前端,用于在旋紧时将弹性筒夹压紧到定位内锥面上；拉头,设置在筒夹夹头的后侧；主轴连接座包括夹头定位孔,筒夹夹头具有外锥面,筒夹夹头的外锥面与夹头定位孔的形状吻合以对筒夹夹头定位；夹头拉爪包括拉杆连接结构,设置在夹头拉爪后端；瓣状爪体,瓣状爪体的径向外侧面具有锥度且朝向斜后方,径向外侧面用于在夹头拉爪向后运动时使瓣状爪体径向收缩而抱住拉头并向后拉动拉头。上述方案解决了现有技术中的车床装卸工件占用时间长、影响生产效率的问题。(The invention relates to a workpiece quick-change tool for a lathe. The lathe is with work piece quick change frock includes: the collet chuck clamp comprises a collet chuck and a collet chuck nut, and the collet chuck nut is in threaded connection with the front end of the collet chuck and is used for pressing the elastic collet chuck onto the positioning inner conical surface when the collet chuck is screwed tightly; the pull head is arranged on the rear side of the collet chuck; the main shaft connecting seat comprises a collet positioning hole, the collet chuck is provided with an outer conical surface, and the outer conical surface of the collet chuck is matched with the shape of the collet positioning hole so as to position the collet chuck; the chuck pull claw comprises a pull rod connecting structure and is arranged at the rear end of the chuck pull claw; the radial outer side surface of the petal-shaped claw body is provided with a taper and faces towards the oblique rear direction, and the radial outer side surface is used for enabling the petal-shaped claw body to contract radially to hold the pull head and pull the pull head backwards when the chuck pull claw moves backwards. By the scheme, the problems that the time for loading and unloading the workpiece by the lathe in the prior art is long and the production efficiency is influenced are solved.)

1. Work piece quick change frock for lathe, its characterized in that includes:

a collet clamp for clamping a resilient collet, the collet clamp comprising:

the collet chuck is internally provided with a collet mounting cavity for the elastic collet chuck to be placed in; the collet mounting cavity is provided with a positioning inner conical surface which is used for being matched with the outer conical surface of the collet so as to position the elastic collet;

the collet chuck nut is in threaded connection with the front end of the collet chuck and is used for pressing the elastic collet chuck onto the positioning inner conical surface when the collet chuck is screwed up, so that the elastic collet chuck is radially contracted to clamp a workpiece;

the pull head is arranged on the rear side of the collet chuck, and the rear end of the pull head is provided with a large-diameter part which is used for bearing backward pulling force;

quick change frock is used to lathe still includes the main shaft connecting seat, the main shaft connecting seat is used for fixing to the lathe main shaft on, include:

the chuck positioning hole is a conical hole which is of a flaring structure with a forward opening;

the collet chuck is provided with an outer conical surface, and the outer conical surface of the collet chuck is matched with the shape of the chuck positioning hole so as to position the collet chuck;

quick change frock is used to lathe still includes the chuck and draws the claw, and the chuck draws the claw to include:

the pull rod connecting structure is arranged at the rear end of the chuck pull claw and is used for being connected with a lathe pull rod so as to enable the chuck pull claw to move back and forth along with the lathe pull rod;

the jaw-shaped claw bodies are arranged at the front ends of the chuck pulling claws, and each jaw-shaped claw body is enclosed into a reducing cavity which is used for holding the large-diameter part of the pulling head when the jaw-shaped claw bodies radially contract along the chuck pulling claws;

the radial outer side surface of the petal-shaped claw body is provided with taper and faces towards the oblique rear direction, and the radial outer side surface is used for being matched with an adaptive inner conical surface arranged on a lathe spindle or a spindle connecting seat so as to enable the petal-shaped claw body to contract radially to hold the puller and pull the puller backwards when the chuck pulling claw moves backwards.

2. The quick-change workpiece tool for the lathe as set forth in claim 1, wherein the spindle connecting seat comprises:

the annular flange part is fixed on the end face of the lathe spindle through bolts;

a claw body fitting portion provided radially inside the annular flange portion, the chuck positioning hole being provided on the claw body fitting portion;

and the connecting part is connected between the front end of the claw body adapting part and the front end of the annular flange part and is used for enabling the claw body adapting part to be backwards embedded into an inner hole of the lathe spindle.

3. The quick-change workpiece tool for the lathe as claimed in claim 2, wherein the radially inner side wall of the annular flange portion is a conical surface for positioning and matching with an outer conical surface of the end portion of a spindle of the lathe.

4. The tool for quickly changing a workpiece for a lathe according to claim 1, 2 or 3, wherein the slider comprises:

the connecting column is protruded backwards from the rear end face of the collet chuck;

the sleeve-shaped main body is provided with a fixing hole at the center and sleeved on the connecting column through the fixing hole;

the large-diameter part of the pull head is arranged on the sleeve-shaped main body, and an axial positioning structure is arranged between the sleeve-shaped main body and the connecting column;

the diameter of the fixing hole is larger than that of the connecting column, so that the sleeve-shaped main body can float on the connecting column in the radial direction.

5. The quick workpiece changing tool for the lathe as claimed in claim 4, wherein a screw hole is formed in the rear end face of the connecting column, a puller screw is fixed in the screw hole, and the head of the puller screw is in axial stop fit with the sleeve-shaped body to form the axial positioning structure.

6. The quick-change workpiece fixture for the lathe as claimed in claim 4, wherein a threaded hole is formed in the rear end face of the collet chuck, and the connecting column and the collet chuck are separately arranged and fixed in the threaded hole in a threaded connection mode.

7. The quick-change tool for the lathe workpiece as claimed in claim 1, 2 or 3, wherein a positioning pin hole is formed in the spindle connecting seat, and a positioning pin is arranged on the rear end face of the collet chuck;

the locating pin hole extends along the front-back direction, and the locating pin hole is used for inserting a locating pin so as to transmit torque between the main shaft connecting seat and the collet chuck.

8. The quick-change tool for the lathe tool as claimed in claim 1, 2 or 3, wherein an annular groove is formed in the inner wall of the chuck positioning hole, and a vent hole is formed in the bottom wall of the annular groove and communicated with the radial outer side of the spindle connecting seat to allow gas to enter.

9. The quick-change tool for the lathe tool as claimed in claim 1, 2 or 3, wherein a positioning plane is arranged on the outer peripheral surface of the collet chuck, and the positioning plane is clamped by a manipulator to realize automatic loading and unloading of the collet chuck.

10. The quick-change tool for the lathe tool as claimed in claim 1, 2 or 3, wherein the chuck pull claw comprises a cylindrical body, and the cylindrical body is used for guiding and arranging along an inner hole of the main shaft;

the outer peripheral surface of the cylindrical main body is provided with a key groove which extends along the axial direction of the cylindrical main body.

Technical Field

The invention relates to a workpiece quick-change tool for a lathe.

Background

The utilization rate and the processing efficiency of the lathe are important factors to be considered when enterprises produce. At present, an elastic collet chuck is a common clamping tool in lathe machining, for example, a collet chuck disclosed in CN209303753U, which is a pull type collet chuck used for clamping when a lathe draw bar is pulled backwards, and is matched with an elastic collet chuck sheet when in use, so that a larger workpiece specification application range can be realized.

The collet chuck comprises a chuck base which is fixed on the end face of a lathe spindle, the chuck base is provided with the collet chuck, the collet chuck is connected with a hydraulic pull rod or a pneumatic pull rod which is arranged on the lathe through a connecting cylinder, the collet chuck can be driven to act when the pull rod acts, the collet chuck is clamped by utilizing a conical surface on a collet chuck flange, and therefore an elastic collet chuck in the collet chuck shrinks to clamp a workpiece. The front end of the elastic collet chuck is also provided with a clamping joint used for preventing the elastic collet chuck from being separated.

However, the workpiece is loaded into the elastic collet chuck manually at present, the automation degree is not high enough, the number of workers on a production line is high, manual clamping time is long, and the influence on the machine tool utilization rate and the overall machining efficiency is large. In addition, for some workpieces, the clamping precision of the detector is required after the clamping is finished, and the process also needs to take a long time and also influences the production efficiency.

Disclosure of Invention

The invention aims to provide a workpiece quick-change tool for a lathe, and solves the problems that in the prior art, the workpiece loading and unloading time is long, and the production efficiency is influenced.

The invention adopts the following technical scheme:

work piece quick change frock for lathe includes:

a collet clamp for clamping a resilient collet, the collet clamp comprising:

the collet chuck is internally provided with a collet mounting cavity for the elastic collet chuck to be placed in; the collet mounting cavity is provided with a positioning inner conical surface which is used for being matched with the outer conical surface of the collet so as to position the elastic collet;

the collet chuck nut is in threaded connection with the front end of the collet chuck and is used for pressing the elastic collet chuck onto the positioning inner conical surface when the collet chuck is screwed up, so that the elastic collet chuck is radially contracted to clamp a workpiece;

the pull head is arranged on the rear side of the collet chuck, and the rear end of the pull head is provided with a large-diameter part which is used for bearing backward pulling force;

quick change frock is used to lathe still includes the main shaft connecting seat, the main shaft connecting seat is used for fixing to the lathe main shaft on, include:

the chuck positioning hole is a conical hole which is of a flaring structure with a forward opening;

the collet chuck is provided with an outer conical surface, and the outer conical surface of the collet chuck is matched with the shape of the chuck positioning hole so as to position the collet chuck;

quick change frock is used to lathe still includes the chuck and draws the claw, and the chuck draws the claw to include:

the pull rod connecting structure is arranged at the rear end of the chuck pull claw and is used for being connected with a lathe pull rod so as to enable the chuck pull claw to move back and forth along with the lathe pull rod;

the jaw-shaped claw bodies are arranged at the front ends of the chuck pulling claws, and each jaw-shaped claw body is enclosed into a reducing cavity which is used for holding the large-diameter part of the pulling head when the jaw-shaped claw bodies radially contract along the chuck pulling claws;

the radial outer side surface of the petal-shaped claw body is provided with taper and faces towards the oblique rear direction, and the radial outer side surface is used for being matched with an adaptive inner conical surface arranged on a lathe spindle or a spindle connecting seat so as to enable the petal-shaped claw body to contract radially to hold the puller and pull the puller backwards when the chuck pulling claw moves backwards.

Has the advantages that: by adopting the technical scheme, after the elastic collet chuck is placed into the collet chuck in the collet chuck clamp, when the collet chuck nut is screwed, the positioning inner conical surface in the collet chuck can be utilized to position the collet chuck and clamp a workpiece, and the collet chuck clamp is an independent part, so that the pre-clamping of the workpiece can be realized outside a lathe, the clamping precision can be detected when needed, and the processing time of the lathe is not occupied; meanwhile, the petal-shaped claw body of the chuck pull claw can be matched with an adaptive inner conical surface arranged on a lathe spindle or a spindle connecting seat, so that the chuck pull claw tightly holds the pull head at the rear part of the collet chuck clamp under the driving of a lathe pull rod and pulls the pull head backwards, the collet chuck clamp is positioned and fixed in a chuck positioning hole on the spindle connecting seat, the clamping of the collet chuck clamp is conveniently realized, and the clamping of a workpiece is realized; compared with the prior art, the clamping of the workpiece in the collet chuck can not occupy the processing time of a lathe, and the collet chuck clamp can also be quickly replaced through the chuck pull claw, so that the time for loading and unloading the workpiece can be greatly saved, the production efficiency and the machine tool utilization rate are improved, and the production cost is reduced.

As a preferred technical scheme: the main shaft connecting seat includes:

the annular flange part is fixed on the end face of the lathe spindle through bolts;

a claw body fitting portion provided radially inside the annular flange portion, the chuck positioning hole being provided on the claw body fitting portion;

and the connecting part is connected between the front end of the claw body adapting part and the front end of the annular flange part and is used for enabling the claw body adapting part to be backwards embedded into an inner hole of the lathe spindle.

Has the advantages that: by adopting the technical scheme, the distance that the collet chuck extends out of the lathe spindle forwards is favorably reduced, so that the integral rigidity is favorably improved, and the processing precision is favorably ensured; in addition, the claw body adapting part is beneficial to reducing the overall radial size of the petal-shaped claw body, the structure is compact, and the weight is also beneficial to reducing.

As a preferred technical scheme: the radial inner side wall of the annular flange part is a conical surface and is used for being matched with an outer conical surface at the end part of a lathe spindle in a positioning mode.

Has the advantages that: by adopting the technical scheme, the assembling precision of the main shaft connecting seat is improved, so that the positioning precision of the collet chuck and the clamping precision of a workpiece are better ensured.

As a preferred technical scheme: the slider includes:

the connecting column is protruded backwards from the rear end face of the collet chuck;

the sleeve-shaped main body is provided with a fixing hole at the center and sleeved on the connecting column through the fixing hole;

the large-diameter part of the pull head is arranged on the sleeve-shaped main body, and an axial positioning structure is arranged between the sleeve-shaped main body and the connecting column;

the diameter of the fixing hole is larger than that of the connecting column, so that the sleeve-shaped main body can float on the connecting column in the radial direction.

Has the advantages that: by adopting the technical scheme, the sleeve-shaped main body can be prevented from being over-positioned due to radial floating, so that the positioning of the collet chuck clamp is completely ensured by the collet chuck positioning hole on the main shaft connecting seat, the influence of manufacturing and assembling errors on the positioning precision of the collet chuck clamp is avoided, the positioning accuracy and the clamping firmness degree of the collet chuck clamp are favorably improved, and the processing precision of a workpiece can be better ensured.

As a preferred technical scheme: the rear end face of the connecting column is provided with a screw hole, a puller screw is fixed in the screw hole, and the head of the puller screw is matched with the sleeve-shaped main body in a blocking manner along the axial direction to form the axial positioning structure.

Has the advantages that: by adopting the technical scheme, the axial positioning structure formed by the puller screws is simple in structure and convenient to process.

As a preferred technical scheme: the rear end face of the collet chuck is provided with a threaded hole, and the connecting column and the collet chuck are arranged in a split mode and are fixed in the threaded hole in a threaded connection mode.

Has the advantages that: by adopting the technical scheme, the collet chuck can be conveniently processed.

As a preferred technical scheme: the main shaft connecting seat is provided with a positioning pin hole, and the rear end face of the collet chuck is provided with a positioning pin;

the locating pin hole extends along the front-back direction, and the locating pin hole is used for inserting a locating pin so as to transmit torque between the main shaft connecting seat and the collet chuck.

Has the advantages that: by adopting the technical scheme, the positioning pin hole and the positioning pin can play a role in auxiliary positioning when the collet chuck clamp is not tensioned by the chuck pulling claw, and can transmit torque between the spindle connecting seat and the collet chuck, so that the requirement of rotating and processing a workpiece on a lathe is better met.

As a preferred technical scheme: the inner wall of the chuck positioning hole is provided with an annular groove, the bottom wall of the annular groove is provided with a vent hole, and the vent hole is used for being communicated to the radial outer side of the spindle connecting seat so as to allow air to enter.

Has the advantages that: by adopting the technical scheme, negative pressure can be prevented from being formed in the main shaft connecting seat when the collet chuck is pulled out, the collet chuck can be pulled out smoothly, particularly, the negative pressure phenomenon is more obvious under the condition that cutting fluid is infiltrated, the main shaft connecting seat is difficult to pull out, and therefore normal processing is influenced.

As a preferred technical scheme: and the outer peripheral surface of the collet chuck is provided with a positioning plane, and the positioning plane is used for clamping by a manipulator so as to realize automatic feeding and discharging of the collet chuck.

Has the advantages that: by adopting the technical scheme, automatic feeding and discharging of the collet chuck clamp can be realized, so that the machining efficiency can be further improved, and the labor consumption is reduced.

As a preferred technical scheme: the chuck pull claw comprises a cylindrical main body, and the cylindrical main body is used for guiding the arrangement along an inner hole of the main shaft;

the outer peripheral surface of the cylindrical main body is provided with a key groove which extends along the axial direction of the cylindrical main body.

Has the advantages that: by adopting the technical scheme, the chuck pull claw is convenient to be matched with a key structure in a lathe spindle, and is also favorable for circumferentially positioning the cylindrical main body, so that the reliable connection of the chuck pull claw and a lathe pull rod is ensured.

The above-described preferred embodiments may be adopted alone, or two or more embodiments may be arbitrarily combined when they can be combined, and the embodiments formed by the combination are not specifically described here and are included in the description of the present patent.

Drawings

Fig. 1 is a schematic structural view of an embodiment 1 of a workpiece quick-change tool for a lathe according to the present invention;

FIG. 2 is a schematic view of the collet chuck in a separated state from the spindle attachment base;

FIG. 3 is an enlarged view of a portion of FIG. 1 at A;

FIG. 4 is a right side view of FIG. 1;

FIG. 5 is a perspective view of the collet fixture;

FIG. 6 is a perspective view of the spindle attachment mount;

FIG. 7 is a cross-sectional view of the spindle attachment base;

FIG. 8 is a first perspective view of the chuck pull jaw;

fig. 9 is a second perspective view of the collet fingers.

The names of the components corresponding to the corresponding reference numerals in the drawings are: 10-a collet chuck clamp, 11-a collet chuck, 12-a collet chuck installation cavity, 13-a positioning inner conical surface, 14-a collet nut, 15-a puller, 16-an outer hexagonal structure, 17-a connecting column, 18-a sleeve-shaped body, 19-a puller screw, 110-a bulging structure, 111 positioning pins, 20-a spindle connecting seat, 21-an annular flange part, 22-a claw body adapting part, 23-a connecting part, 24-a collet positioning hole, 25-an annular groove, 26-a vent hole, 27-a positioning pin hole, 30-a collet pulling claw, 31-a barrel-shaped body, 32-a petal-shaped claw body, 33-a key groove, 34-a middle annular groove, 40-an elastic collet chuck and 50-a lathe spindle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that relational terms such as "first" and "second," and the like, which may be present in the embodiments of the present invention, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the statement that "comprises an … …" is intended to indicate that there are additional elements of the same process, method, article, or apparatus that comprise the element.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" when they are used are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, or may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from specific situations.

In the description of the present invention, unless otherwise specifically stated or limited, the term "provided" may be used in a broad sense, for example, the object of "provided" may be a part of the body, or may be arranged separately from the body and connected to the body, and the connection may be detachable or non-detachable. The specific meaning of the above terms in the present invention can be understood by those skilled in the art from specific situations.

The present invention will be described in further detail with reference to examples.

Embodiment 1 of the quick-change tool for lathe workpieces of the present invention: as shown in fig. 1, 2 and 4, the quick-change tool for lathe parts comprises three major parts, namely a collet fixture 10, a spindle connecting seat 20 and a collet pulling claw 30. The collet chuck clamp 10 is used for clamping the elastic collet chuck 40, so that the workpiece in the elastic collet chuck 40 can be clamped; the spindle connecting seat 20 is used for being fixedly connected to the front end face of the lathe spindle 50, provides positioning for the collet fixture 10 and can be used as a fixing base of the collet fixture 10; the collet chuck jaws 30 are used to connect to a lathe tie bar (not shown in the drawings, which is a structure commonly used in a numerically controlled lathe and can be generally classified into a hydraulic tie bar and a pneumatic tie bar), so as to clamp and release the collet chuck 10 when the lathe tie bar moves back and forth, thereby clamping and discharging a workpiece. The end structure of the lathe spindle 50, which has an inner tapered surface and an outer tapered surface as shown in fig. 1 and 2, is a common lathe spindle structure and will not be described in detail herein. The elastic collet chuck 40 is a common fixture on a machine tool, and is an ER collet chuck in the embodiment, and the shape of the ER collet chuck can refer to a collet chuck used in CN209303753U cited in figure 1 and the background of the invention, and can generate radial elastic contraction and expansion under the action of external force, so as to clamp and release a workpiece; the elastic collet 40 is not part of the tool for quickly replacing the workpiece for the lathe, is used together with the tool during machining, and the specific structure is not described in detail here.

As shown in fig. 1, 2 and 5, the collet clamp 10 includes a collet chuck 11, a collet nut 14 and a pull head 15. A collet mounting cavity 12 is arranged in the collet chuck 11, and the elastic collet 40 is placed in the collet mounting cavity 12; the collet mounting cavity 12 has a locating internal taper 13, the locating internal taper 13 being adapted to fit with the external taper of the collet to locate the resilient collet 40. The outer periphery of the front end of the collet chuck 11 is provided with external threads, and the collet nut 14 is an ER nut matched with an ER collet and is in threaded connection with the front end of the collet chuck 11 and used for pressing the elastic collet chuck 40 onto the positioning inner conical surface 13 when the collet chuck is tightened, so that the elastic collet chuck 40 contracts radially to clamp a workpiece. Of course, as a known structure, the collet nut 14 has a collet stop flange at the front end of the central hole, and can be fitted into the elastic collet 40. The outer hexagonal structure 16 is arranged on the outer peripheral surface of the collet chuck 11, and the outer hexagonal structure 16 forms a positioning plane for clamping by a manipulator to realize high-precision quick change of the collet chuck fixture 10, so that the requirement of automatic feeding and discharging is met.

A pull head 15 is provided at the rear side of the collet chuck 11 for pulling the collet chuck 10 rearward by the chuck pull jaws 30. As shown in fig. 3, the slider 15 includes a connecting post 17, a sleeve-shaped body 18, and a slider screw 19; specifically, a threaded hole is formed in the center of the rear end face of the collet chuck 11, and an external thread is formed at the front end of the connecting column 17 and is fitted into the threaded hole through the external thread. The axial middle part of the connecting column 17 is provided with a shaft shoulder which is matched with the rear end face of the collet chuck 11 in a stopping way, so that the connecting column 17 is ensured to be connected in place and fixed firmly, and the connecting column 17 protrudes out of the rear end face of the collet chuck 11 after being assembled in place. The connecting post 17 is arranged separately from the collet chuck 11 in the above-described manner, which facilitates the processing of the collet chuck 11. The center of the sleeve-shaped main body 18 is provided with a fixing hole which is sleeved on the connecting column 17; the rear end of the sleeve-shaped body 18 is provided with a bulging structure 110, and the bulging structure 110 has a front side tapered surface and a rear side tapered surface to form a large diameter portion for receiving a rearward pulling force. The rear end of the fixing hole is provided with a large-diameter section to form a counter bore; the rear end face of the connecting column 17 is provided with a screw hole, a puller screw 19 is fixed in the screw hole, the head of the puller screw 19 is in axial stop fit with the sleeve-shaped main body 18 through a large-diameter section to form an axial positioning structure, and the backward pulling force applied to the sleeve-shaped main body 18 can be transmitted to the collet chuck 11 through the puller screw 19. The diameter of the fixing hole in the sleeve-shaped body 18 is greater than the diameter of the connecting column 17, so that the sleeve-shaped body 18 can float radially on the connecting column 17.

As shown in fig. 2, 6 and 7, the spindle connection base 20 includes an annular flange portion 21, a claw body fitting portion 22, and a connection portion 23, the annular flange portion 21 and the claw body fitting portion 22 being coaxially arranged with the claw body fitting portion 22 being disposed radially inside the annular flange portion 21. The annular flange part 21 is used for being fixed on the end face of the lathe spindle 50 through bolts, the radial inner side wall of the annular flange part 21 is a conical surface and is used for being matched with the outer conical surface of the end part of the lathe spindle 50 in a positioning mode, the assembly accuracy of the spindle connecting seat 20 is improved, and therefore the positioning accuracy of the collet chuck 11 and the clamping accuracy of workpieces are better guaranteed. The claw body adapting part 22 is provided with a chuck positioning hole 24, the chuck positioning hole 24 is a tapered hole, and the tapered hole is an expanding structure with a forward opening; the collet chuck 11 has an outer tapered surface, and the outer tapered surface of the collet chuck 11 is matched with the shape of the chuck positioning hole 24 to position the collet chuck 11. A connecting portion 23 connects a front end of the claw body fitting portion 22 and a front end of the annular flange portion 21 for fitting the claw body fitting portion 22 rearward into the inner bore of the lathe spindle 50. The connection between the front of the annular flange portion 21 and the front of the claw body fitting portion 22 via the connecting portion 23 enables the claw body fitting portion 22 to be retracted into the lathe spindle 50, thereby enabling the distance by which the collet chuck 11 projects forward out of the lathe spindle to be reduced. The inner conical surfaces of the hole wall of the chuck positioning hole 24 on the main shaft connecting seat 20 and the radial inner side wall of the annular flange part 21 are both subjected to fine grinding, so that the matching precision can be ensured, and the clamping precision of a workpiece on the lathe main shaft 50 can be further ensured. The inner wall of the chuck positioning hole 24 is provided with an annular groove 25, vent holes 26 are uniformly distributed on the groove bottom wall of the annular groove 25 along the circumferential direction, and the vent holes 26 are used for being communicated with the radial outer side of the spindle connecting seat 20 to allow air to enter, so that negative pressure is prevented from being formed in the spindle connecting seat 20 when the collet chuck 11 is pulled out, and the collet chuck 11 can be pulled out smoothly.

In order to meet the torque born by the workpiece during processing, a positioning pin hole 27 is arranged on the main shaft connecting seat 20, and a positioning pin 111 is arranged on the rear end face of the collet chuck 11; the positioning pin hole 27 extends in the front-back direction, and the positioning pin hole 27 and the positioning pin 111 can play a role in auxiliary positioning when the collet fixture 10 is not tensioned by the collet pulling claws 30, and can transmit torque between the spindle connecting seat 20 and the collet chuck 11, so that the requirement of rotating and processing a workpiece on a lathe can be better met. In this embodiment, the positioning pin holes 27 and the positioning pins 111 are respectively provided at three positions and are uniformly distributed in the circumferential direction.

As shown in fig. 8 and 9, the chuck pull claw 30 includes a cylindrical main body 31 and a claw body 32, the cylindrical main body 31 is arranged to be guided along the inner hole of the spindle, a key groove 33 is formed on the outer circumferential surface of the cylindrical main body 31, and the key groove 33 extends in the axial direction of the cylindrical main body 31. The cylindrical main body 31 is also provided with a middle ring groove 34 in the circumferential middle part, and the key groove 33 and the middle ring groove 34 are both used for being matched with a key structure in the lathe spindle 50. The key groove 33 is convenient to be matched with a key structure in the lathe spindle 50, and is also beneficial to circumferentially positioning the cylindrical main body 31, so that the reliable connection between the chuck pull claw 30 and a lathe pull rod is ensured. The rear end portion of the cylindrical body 31 is provided with external threads which form a pull rod connection structure for connection with a lathe pull rod to move the collet chuck 30 back and forth with the lathe pull rod. A tapered cylindrical portion is provided between the claw body 32 and the cylindrical body 31, and is transitionally connected by the tapered cylindrical portion. Each petal-shaped claw body 32 is enclosed into a necking cavity, and the necking cavity is used for holding the large-diameter part of the pull head 15 when the petal-shaped claw bodies 32 are radially shrunk along the chuck pull claw 30; the radial outer side surface of the claw body 32 has a taper and faces towards the oblique rear direction, and the radial outer side surface is adapted to an adaptive inner tapered surface arranged on the spindle connecting seat 20, so that when the chuck pull claw 30 moves backwards, the claw body 32 contracts radially to clasp the pull head 15 and pull the pull head 15 backwards.

When the lathe draw bar is not tensioned, the petal-shaped claw body 32 of the chuck pull claw 30 is in a loosening state, the inner diameter of the pull claw is slightly larger than the outer diameter of the pull head 15 at the moment, and the pull head 15 can freely enter and exit the necking inner cavity of the chuck pull claw 30; before the automatic production line is operated, the collet clamp 10 and the elastic collet chuck 40 placed in the collet chuck are used for clamping the rod materials out of the production line. Then, the robot can grip the hexagonal structure 16 on the collet chuck 11 to automatically load and unload the workpiece. Specifically, when the numerical control lathe needs to be loaded, an automatic device or a mechanical hand operates the collet fixture 10 and a workpiece thereon to the vicinity of a lathe spindle 50, a lathe pull rod is loosened, a petal-shaped claw body 32 of a collet pull claw 30 is enlarged, and when the collet fixture 10 is conveyed to a state shown in fig. 1, the mechanical hand loosens the collet fixture 10, and a positioning pin 111 on a collet chuck 11 is inserted into a positioning pin hole 27 on a spindle connecting seat 20 and plays a temporary supporting role through the positioning pin 111 and the positioning pin hole 27; when the feeding is finished, the lathe pull rod is tensioned leftwards, the inner diameter of the chuck pull claw 30 is contracted under the action of the adaptive inner conical surface arranged on the spindle connecting seat 20, and the pull head 15 and the chuck clamp 10 are tensioned. The chuck positioning hole 24 on the spindle flange is matched with the peripheral surface of the chuck 11 of the collet chuck, so that the high-precision positioning effect is achieved.

Example 2 in the present invention:

the difference between the present embodiment and embodiment 1 is that the slider 15 in embodiment 1 includes a connecting post 17 and a sleeve-shaped body 18, the connecting post 17 and the collet chuck 11 are arranged separately, and in the present embodiment, the connecting post 17 is integrally provided on the collet chuck 11.

Example 3 in the present invention:

the difference between this embodiment and embodiment 1 is that in embodiment 1, the sleeve-shaped main body 18 of the slider 15 is sleeved on the connecting post 17 in a radially floating manner, whereas in this embodiment, the sleeve-shaped main body 18 and the connecting post 17 are positioned and matched in a radial direction, and the problem of over-positioning is avoided by virtue of slight deformation of the petal-shaped claws 32. Of course, in other implementations, the pull head 15 may be a single piece.

Example 4 in the present invention:

the present embodiment is different from embodiment 1 in that, in embodiment 1, both sides of the large diameter portion of the slider 15 are cylindrical surfaces, whereas in the present embodiment, the large diameter portion of the slider 15 is formed by an outer flange on the sleeve-shaped body 18, and a front end face of the outer flange is used for axially stop-fitting with a petal-shaped body on the chuck jaws 30.

Example 5 in the present invention:

the difference between this embodiment and embodiment 1 is that in embodiment 1, the radial outer side surface of the petal-shaped claw body 32 is adapted to the adaptive inner conical surface arranged on the spindle connecting seat 20, so that when the chuck pull claw 30 moves backward, the petal-shaped claw body 32 contracts radially to hold the slider 15 and pull the slider 15 backward, while in this embodiment, the spindle connecting seat 20 is not provided with the adaptive inner conical surface, and when in use, the radial outer side surface of the petal-shaped claw body 32 is directly adapted to the adaptive inner conical surface on the lathe spindle 50.

Example 6 in the present invention:

the difference between this embodiment and embodiment 1 is that the spindle connecting base 20 in embodiment 1 includes an annular flange portion 21 and a claw body fitting portion 22, and the claw body fitting portion 22 is protruded rearward, whereas in this embodiment, the spindle connecting base 20 is disposed at the front side of the annular flange portion 21, so that the spindle connecting base 20 can be processed more conveniently.

Example 7 in the present invention:

the difference between this embodiment and embodiment 1 is that in embodiment 1, the spindle connecting seat 20 is adapted to the outer conical surface of the lathe spindle 50 through the inner conical surface, and in this embodiment, the spindle connecting seat 20 is provided with an outer conical positioning surface adapted to the inner conical surface of the inner bore of the lathe spindle 50 through the outer conical positioning surface.

The above description is only a preferred embodiment of the present application, and not intended to limit the present application, the scope of the present application is defined by the appended claims, and all changes in equivalent structure made by using the contents of the specification and the drawings of the present application should be considered as being included in the scope of the present application.