CN110666546A

CN110666546A - Clamping mechanism and fast-assembling positioning fixture

Info

Publication number: CN110666546A
Application number: CN201910982229.2A
Authority: CN
Inventors: 张国新; 张怡帆
Original assignee: Wuxi Professional College of Science and Technology
Current assignee: Wuxi Professional College of Science and Technology
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-01-10

Abstract

The invention provides a clamping mechanism and a quick-mounting positioning fixture, wherein the clamping mechanism comprises: the positioning fixture, a pressing block which transversely clamps a workpiece together with the positioning fixture, a positioning sheet which is arranged at the bottom of the positioning fixture and is square, and a blind rivet which is partially arranged in the positioning fixture and vertically penetrates through the positioning sheet downwards, wherein a circle of groove is annularly arranged on the side part of the blind rivet, and the positioning fixture forms a containing blind hole with threads and is in threaded connection with the top of the blind rivet through the containing blind hole; four positioning columns are vertically and convexly arranged at four corners of the positioning sheet, first positioning holes which are in cross orthogonal arrangement are formed in the positioning sheet, and positioning blind holes matched with the first positioning holes are formed in the positioning fixture. The clamping mechanism and the quick-mounting positioning fixture disclosed by the invention have the advantages of simplicity in operation, lower use cost, higher practicability and the like, the clamping and positioning effects on the workpiece are obviously improved, the quick replacement operation on the workpiece is realized, and the replacement time of the workpiece is reduced.

Description

Clamping mechanism and fast-assembling positioning fixture

Technical Field

The invention relates to the technical field of tool fixtures, in particular to a clamping mechanism and a quick-mounting positioning fixture based on the clamping mechanism.

Background

A quick-mounting positioning clamp is a device commonly used in modern machine tools and used for connecting a power mechanism of the machine tool with a workpiece. The machine tool processes the workpiece by the tool according to a set program. The fast-assembling positioning fixture is an indispensable part for machining, and under the drive that the machine tool technology develops towards the directions of high speed, high efficiency, precision, composition, intelligence and environmental protection, the fixture technology develops towards the directions of high precision, high efficiency, module, combination, universality and economy, so that higher requirements are put forward on the fast-assembling positioning fixture.

The fast-assembling positioning fixture has good precision on ensuring the repeated positioning precision of the workpiece fixture through the perfect combination of rigidity and flexibility. In the prior art, the conventional tool clamp needs to be adjusted and positioned manually. Due to the fact that the shapes and the types of workpieces to be machined are greatly different, the positioning clamp in the prior art has the defects of poor universality, poor clamping and positioning effects, inconsistent machining precision and the like when the workpieces are repeatedly clamped, and the machining requirements of workpieces with complex shapes and small batches cannot be met.

In view of the above, there is a need for an improved positioning fixture in the prior art to solve the above problems.

Disclosure of Invention

The invention aims to disclose a clamping mechanism and a quick-mounting positioning fixture based on the clamping mechanism, which are used for realizing quick reloading operation of workpieces, reducing reloading time of the workpieces and improving clamping effect of the workpieces.

In order to achieve the first object, the present invention provides a clamping mechanism for clamping a workpiece, the clamping mechanism comprising:

the positioning fixture comprises a positioning fixture, a pressing block which transversely clamps a workpiece together with the positioning fixture, a positioning sheet which is arranged at the bottom of the positioning fixture and is square, and a blind rivet which is partially arranged in the positioning fixture and vertically penetrates through the positioning sheet downwards, wherein a circle of groove is annularly arranged on the side part of the blind rivet, the positioning fixture forms a containing blind hole with threads, and the blind hole is in threaded connection with the top of the blind rivet;

the locating piece is provided with a first locating hole which is in cross-shaped orthogonal arrangement, and the locating fixture is provided with a locating blind hole matched with the first locating hole.

In a further improvement of the present invention, the top of the positioning fixture forms a receiving portion for receiving the workpiece, and the lateral side of the receiving portion forms an opening, and the pressing block is transversely disposed in the opening so as to clamp the bottom of the workpiece together with the positioning fixture and the pressing block.

As a further improvement of the invention, the side of the positioning jig houses a sensor.

As a further improvement of the present invention, a first limiting groove is formed at the bottom of the positioning fixture, a second limiting groove is formed at the bottom of the compressing block, the first limiting groove and the second limiting groove are oppositely arranged, the extending direction of the first limiting groove and the extending direction of the second limiting groove are in a perpendicular relationship, and the first limiting groove forms a positioning notch;

two second positioning holes which are oppositely arranged are formed in the bottom of the positioning clamp;

the positioning notch, the second limiting groove and the two second positioning holes are arranged in a cross-shaped orthogonal mode relative to the blind rivet.

As a further improvement of the invention, the top of the groove forms three continuous adjacent rectangular planes and an arc-shaped plane;

wherein a rectangular plane in the middle is arranged facing the compact.

Based on the same idea and to achieve the second objective, the present application further discloses a quick-assembly positioning fixture, which includes the clamping mechanism according to any one of the above inventions, an

The positioning seat, a base connected with the positioning seat, a cylinder, a spring and a steel ball;

wherein,

the top of the positioning seat is provided with four prism positioning teeth which are arranged in a cross-orthogonal manner and four positioning grooves which are arranged in a cross-orthogonal manner and are used for partially accommodating the positioning columns, and the prism positioning teeth and the positioning grooves are uniformly arranged at intervals in an annular manner;

the positioning seat comprises a positioning seat body and a shaft sleeve which is arranged in the positioning seat body and used for accommodating the blind rivet, a plurality of cylinders are arranged between the shaft sleeve and the positioning seat body in an annular axial symmetry mode, a lower blind hole is formed in each cylinder, an upper blind hole is formed in each positioning seat body, the lower blind hole and the upper blind hole jointly accommodate the end parts of two ends of the spring, and a second through hole for accommodating the steel ball is formed in each shaft sleeve;

the side part of the base is provided with a first air hole, the bottom of the base is provided with a hollow channel, the cylinder moves up and down under the driving of gas, and pushes the steel balls to be clamped into the grooves of the blind rivet when the cylinder moves down, so that the blind rivet is limited to move in the vertical direction through the steel balls.

As a further improvement of the invention, the prismatic positioning teeth form a first positioning edge and a second positioning edge which are separated from each other, and the first positioning edge extends out of the first positioning hole and partially extends into the positioning blind hole.

As a further improvement of the invention, a containing gap is formed on the inner side of the cylinder, and when the cylinder moves upwards, the steel ball is driven by an annular inclined plane formed by a flange at the bottom of the blind rivet so as to push the steel ball into the containing gap; when the cylinder moves downwards, the steel ball is pressed into the groove by the cylinder, so that the annular inclined surface is pressed through the steel ball to limit the movement of the blind rivet in the vertical direction.

As a further improvement of the invention, the side part of the flange is attached to the inner wall surface of the shaft sleeve, the bottom of the blind rivet is provided with an inner hexagonal blind hole, the position of the blind rivet in the vertical direction in the shaft sleeve is adjusted by rotating the blind rivet, and the sum of the depth of the accommodating gap, the thickness of the shaft sleeve and the depth of the groove is larger than the diameter of the steel ball.

As a further improvement of the invention, a second air hole is arranged at the side part of the base, a round positioning surface is formed at the bottom of the positioning column, an air suction hole communicated with the second air hole is formed at the bottom of the positioning groove, part of the positioning column is embedded into the positioning groove and covers the air suction hole through the positioning surface, and the second air hole is connected with an air generating device.

Compared with the prior art, the invention has the beneficial effects that:

the clamping mechanism and the quick-mounting positioning fixture disclosed by the invention have the advantages of simplicity in operation, lower use cost, higher practicability and the like, the clamping and positioning effects on the workpiece are obviously improved, the quick replacement operation on the workpiece is realized, and the replacement time of the workpiece is reduced.

Drawings

FIG. 1 is a perspective view of a clamping mechanism included in a quick mount positioning fixture of the present invention shown from a first perspective view when clamping a workpiece;

FIG. 2 is a perspective view of a clamping mechanism included in a quick mount positioning fixture of the present invention shown from a second perspective view;

FIG. 3 is a perspective view of a clamping mechanism included in the quick-mount positioning fixture for clamping a workpiece according to a third aspect of the present invention;

FIG. 4 is a top view of a quick-mounting positioning fixture of the present invention clamping a workpiece;

FIG. 5 is a cross-sectional view taken along line B-B of FIG. 4;

FIG. 6 is a partial enlarged view of FIG. 5 at arrow C;

FIG. 7 is a perspective view of a quick mount positioning fixture of the present invention clamping a workpiece from a first perspective;

FIG. 8 is an enlarged view of a portion of FIG. 7 at arrow D;

FIG. 9 is a perspective view of a quick mount positioning fixture of the present invention clamping a workpiece from a second perspective;

FIG. 10 is a perspective view of a quick mount positioning fixture of the present invention clamping a workpiece from a third perspective;

fig. 11 is a cross-sectional view longitudinally cutting the positioning seat and the base and showing the air suction hole and the second air hole.

Detailed Description

The present invention is described in detail with reference to the embodiments shown in the drawings, but it should be understood that these embodiments are not intended to limit the present invention, and those skilled in the art should understand that functional, methodological, or structural equivalents or substitutions made by these embodiments are within the scope of the present invention.

It will be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," "positive," "negative," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing and simplifying the description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered as limiting the present disclosure.

The first embodiment is as follows:

please refer to fig. 1 to 3, which illustrate an embodiment of a clamping mechanism according to the present invention.

The clamping mechanism is located above the positioning fixture 30 and the positioning seat 40, and together form a fast-assembling positioning fixture as indicated in the second embodiment.

In the present embodiment, a clamping mechanism is used for clamping a workpiece a. This fixture includes: the positioning fixture 30, the pressing block 10 which transversely clamps the workpiece A together with the positioning fixture 30, the positioning plate 80 which is arranged at the bottom of the positioning fixture 30 and is square, part of the blind rivet 20 which is arranged in the positioning fixture 30 and vertically penetrates through the positioning plate 80 downwards, a circle of groove 21 is annularly arranged on the side part of the blind rivet 20, the positioning fixture 30 forms a threaded accommodating blind hole 18, and the blind hole 18 is in threaded connection with the top of the blind rivet 20. The blind rivet 20 is vertically embedded in the positioning seat 40 of the quick-assembly positioning fixture as disclosed in the second embodiment, and the locking and releasing operations of the blind rivet 20 are realized by utilizing the up-and-down movement of the cylinder 41 in the vertical direction and embedding in or separating from the groove 21 by means of the steel ball 60, so that the fixing and releasing operations of the clamping mechanism disclosed in the second embodiment are realized through the positioning seat 40.

Specifically, the top of the positioning jig 30 forms an accommodating portion 301 for accommodating the workpiece, the lateral side of the accommodating portion 301 forms an opening 302, and the pressing block 10 is disposed laterally in the opening 302 so as to clamp the bottom a1 of the workpiece a laterally by the positioning jig 30 and the pressing block 10. The receiving portion 301 is rectangular, and three sides of the receiving portion protrude upwards to form an opening 302. In the present embodiment, three sides are fixed and protruded upward, and by the pressing block 10 being wedged into the opening portion 302 laterally, four sides of the sheet-like base a1 of the workpiece a are clamped laterally by the positioning jig 30 and the pressing block 10, respectively, thereby improving the efficiency and speed of clamping the workpiece a.

As shown in fig. 5, the side of the positioning jig 30 accommodates a sensor 31. The side of the positioning jig 30 is formed with a blind hole having an internal thread, and the sensor 31 is screwed and integrally put into the blind hole having the internal thread. The sensor 31 may be an RFID chip or other semiconductor device of the same or equivalent type and having information representing the attribute (e.g., machining serial number) of the workpiece a, so as to record and display information on the flexible production line on the position of the workpiece a, whether machining is completed, whether the workpiece a to be machined is present at the machining station of the machine tool, and the like. The sensor 31 can communicate with a background upper computer in a wireless mode to display the processing station information of the workpiece A and the like in real time in the upper computer.

The pressing block 10 is provided with a first through hole 101 transversely penetrating through the pressing block 10, a screw 102 transversely penetrates through the first through hole 101 and is connected with the positioning fixture 30, so that the bottom of the workpiece A is transversely clamped by the positioning fixture 30 and the pressing block 10 together, and four positioning columns 81 are vertically and convexly arranged at four corners of the positioning sheet 80. The positioning plate 80 is provided with first positioning holes 82 which are arranged in a cross-shaped and orthogonal manner. The positioning jig 30 forms a blind positioning hole 15 which is fitted with the first positioning hole 82. The positioning blind hole 15 is used for inserting the first positioning edge 43 included in the prism positioning teeth 49 of the quick-mounting positioning fixture disclosed in the second embodiment, so that the whole clamping mechanism is positioned by the first positioning edge 43.

Referring to fig. 3, in this embodiment, a first limiting groove 13 is disposed at the bottom of the positioning fixture 30, a second limiting groove 12 is disposed at the bottom of the pressing block 10, the first limiting groove 13 and the second limiting groove 12 are disposed in opposite directions, the extending direction of the first limiting groove 13 is perpendicular to the extending direction of the second limiting groove 12, and the first limiting groove 13 forms a positioning notch 131. Two second positioning holes 14 are provided at the bottom of the positioning jig 30 so as to be opposed to each other. More specifically, a connecting line between the positioning notch 131 and the second limiting groove 12 extends through the central axis of the blind rivet 20 and coincides with a connecting line between the two first positioning holes 82. The line between two second positioning holes 14 extends through the central axis of the blind rivet 20 and coincides with the line between the other two first positioning holes 82. The four first positioning holes 82 are orthogonally arranged, and a connecting line formed between the positioning notch 131 and the second positioning groove 12 is orthogonally perpendicular to a connecting line formed between the two second positioning holes 14, so that the positioning notch 131, the second positioning groove 12 and the two second positioning holes 14 are orthogonally arranged with respect to the blind rivet 20.

In particular, in the present embodiment, the top of the groove 21 forms three continuous adjacent rectangular planes and one arc-shaped plane, and specifically three continuous adjacent

rectangular planes

231, 232, 233 and 234. The rectangular plane 232 in the middle is configured to face the pressing block 10, that is, the rectangular plane 232 and the pressing block 10 are oppositely arranged in the direction of the transverse insertion opening 302, so that the pressing block 10 is always kept to be wedged into the notch 302 in the direction of the rectangular plane 232 when being transversely inserted into the opening 302, the processing requirements of a flexible production line or a numerical control machine tool or a processing center are facilitated, particularly, the accuracy of the transverse insertion opening 302 of the pressing block 10 in the spatial position is improved through the synergistic effect of an external sensor, and the technical effect of 'fool-proof design' is achieved. As shown in fig. 5, when the blind rivet 20 is inserted into the vertical channel formed by the shaft sleeve 70 disposed inside the positioning seat 40 and accommodating the blind rivet 20, three continuous adjacent rectangular planes and an arc-shaped plane can be formed at the top of the groove 21 to prompt whether the vertical insertion direction of the blind rivet 20 is correct, thereby further realizing the technical effect of "fool-proof design".

It should be noted that, in this embodiment, although the reference numerals "131", "13", "12", and "14" are respectively defined as "positioning notch", "first limiting groove", "second limiting groove", and "second positioning hole" in the embodiments of the present application, in the actual use process, the positioning or limiting effect on the prism positioning teeth 49 with different shapes or different sizes may be achieved, and the "clearance" design may be used only, and does not participate in specific positioning or limiting. Meanwhile, the top of the positioning fixture 30 is in surface contact with the workpiece a, so that the workpiece a is prevented from being scratched or crushed when the blind rivet 20 is tightened and locked. Meanwhile, the positioning clamp 30 and the pressing block 10 transversely clamp the workpiece A, so that the clamping mechanism can meet the clamping and fixing requirements of workpieces with different sizes in a certain range, the adaptability of the clamping mechanism to workpieces with small batches and different specifications is improved, the clamping mechanism has stronger practicability and universality, frequent replacement of different clamping mechanisms is avoided, and the processing cost of the workpieces is reduced.

Example two:

referring to fig. 4 to 11, this embodiment discloses an embodiment of a quick-mounting positioning fixture based on a clamping mechanism disclosed in the first embodiment.

The fast-assembling positioning fixture disclosed in this embodiment can be used in a CNC system (computer numerical control machine system), and can be used for various mechanical forming operations or applications such as wire cutting, turning, milling, planing, and the like, and is integrally fixed on a machine tool, and under the action of a tool, a metal workpiece a is formed. In this embodiment, the quick-assembly positioning fixture includes a clamping mechanism as disclosed in the first embodiment, a positioning seat 40 located below the clamping mechanism and used for receiving the blind rivet 20 and locking or releasing the blind rivet 20, a base 50 connected to the positioning seat 40, a cylinder 41, a spring 88 and a steel ball 60. The cylinder 41, the spring 88 and the steel ball 60 are all accommodated inside the positioning seat 40. The positioning seat 40 and the base 50 vertically penetrate through the positioning seat 40 through eight bolts 45 and are in threaded connection with a blind hole with an internal thread correspondingly arranged on the base 50, so that the positioning seat 40 and the base 50 are reliably assembled.

Specifically, in the present embodiment, four prism positioning teeth 49 arranged in a cross-orthogonal manner and four positioning grooves 400 arranged in a cross-orthogonal manner and used for partially receiving the positioning posts 81 are disposed on the top of the positioning seat 40. The prism positioning teeth 49 and the positioning grooves 400 are arranged at equal intervals in a ring shape. The connecting line between the two oppositely disposed prismatic positioning teeth 49 extends through the central axis of the blind rivet 20 in the vertical direction thereof, and similarly to the above, the connecting line between the two oppositely disposed positioning grooves 400 extends through the central axis of the blind rivet 20 in the vertical direction thereof. The angle between the longitudinal extension of the prismatic positioning teeth 49 and the longitudinal extension of the positioning slot 400 is 45 degrees.

In this embodiment, the positioning seat 40 includes a positioning seat body 401, and a shaft sleeve 70 disposed in the positioning seat body 401 and accommodating the blind rivet 20, wherein a plurality of air cylinders 41 are disposed between the shaft sleeve 70 and the positioning seat body 401 in an annular axial symmetry manner, the air cylinders 41 form a lower blind hole 411, and the positioning seat body 401 forms an upper blind hole 404. So that the two end portions of the spring 88 are received by the lower blind hole 411 together with the upper blind hole 404. The bushing 70 forms a second through hole 701 that receives the steel ball 60. The side of the base 50 is provided with a first air hole 51, and the bottom of the base 50 is provided with a hollow passage 53. The first air hole 51 is communicated with a shielding cavity formed by the positioning seat body 401 and the mounting seat 50 through a channel 511 arranged inside the mounting seat 50, so that the high-pressure air input from the first air hole 51 exerts a vertical upward thrust force on the bottom surface 414 of the air cylinder 41 against the spring 88. When the clamping mechanism needs to be removed, the first air hole 51 stops introducing high-pressure air into the shielding cavity, and the air cylinder 41 is pushed back to the state shown in fig. 5 under the action of the resilience force of the spring 88, and at this time, the air cylinder 41 is located at the bottommost part of the positioning seat body 401 and contacts with the upper top surface of the base 50.

The cylinder 41 moves up and down by the driving of the gas, and pushes the steel ball 60 and snaps into the groove 21 of the blind rivet 20 when the cylinder 41 moves down, so that the movement of the blind rivet 20 in the vertical direction is limited by the steel ball 60. The hollow channel 53 vertically extends to the bottom of the blind rivet 20 to form a hexagonal blind hole 27, and the interior of the positioning seat 40 can be cleaned through the hollow channel 53. The base 50 is provided with two counter bores 54 at the sides of the hollow channel 53 to secure the entire quick mount positioning fixture to the machine tool via the counter bores 54. Meanwhile, a through hole 55 vertically penetrating the base 50 and having an internal thread is further provided on the base 50. When the quick-mounting positioning fixture is mounted on a machine tool, the quick-mounting positioning fixture can be screwed into the through hole 55 through a headless screw to adjust the levelness of the quick-mounting positioning fixture.

The prism positioning teeth 49 form a first positioning edge 43 and a second positioning edge 44 which are separated from each other, and the first positioning edge 43 extends through the first positioning hole 82 and partially extends into the positioning blind hole 15. The inner side of the cylinder 41 is provided with a receiving notch 406, and when the cylinder 41 moves upwards, the steel ball 60 is driven by an annular inclined surface 221 formed by the flange 22 at the bottom of the rivet 20 so as to push the steel ball 60 into the receiving notch 406; when the cylinder 41 moves downward, the steel ball 60 is pressed into the groove 21 by the cylinder 41 to press the annular inclined surface 221 by the steel ball 60 to limit the movement of the blind rivet 20 in the vertical direction.

The applicant elaborates on how the blind rivet 20 is locked and released by the movement of the steel ball 60 as follows.

Referring to fig. 5 and 6, in the present embodiment, at least two air cylinders 41 are disposed in the positioning seat 40, but three or more air cylinders 41 may be disposed. The number of the air cylinders 41 is equal to that of the steel balls 60; meanwhile, the cylinders 41 are distributed in an axially symmetric annular equal interval distribution relative to the blind rivet 20, so that the steel balls 60 are driven to be pressed into the grooves 21 or separated from the grooves 21 based on the up-and-down movement of the cylinders 41 in the vertical direction, so that the steel balls 60 press or contact and press the annular inclined surfaces 221 arranged at the bottoms of the grooves 21. When the steel ball 60 presses the annular inclined surface 221, the pull nail 20 is locked through the steel ball 60; when the steel ball 60 does not press the annular slope 221 and retreats radially outward into the second through hole 701, the lock of the blind rivet 20 is released, so that the entire clamping mechanism can be pulled out from the hollow passage formed inside the sleeve 70.

Specifically, the annular inclined surface 221 forms an angle of 45 degrees with the horizontal plane. The radial inner side of the cylinder 41 is formed with a housing notch 406. The top of the receiving notch 406 is configured with a slope 415 and a slope 416 arranged in series, and a protrusion 417 is provided at the inner top of the cylinder 41 near one side of the sleeve 70. The height of the protrusion 417 in the vertical direction is higher than the upper edge of the second through hole 701 no matter whether the steel ball 60 locks or unlocks the blind rivet 20 or during the conversion process between the two states, so as to completely block and prevent the steel ball 60 from sliding into a shielding cavity formed by the cylinder 41, the positioning seat body 401 and the shaft sleeve 70, and the shielding cavity allows the cylinder 41 to move up and down. Meanwhile, the steel ball 60 can be more smoothly pressed into the groove 21 by the cylinder 41 driven by the spring 88 and moving downward by providing the inclined surface 415 and the inclined surface 416 arranged in series. On the contrary, when the cylinder 41 moves upwards, the pressing process of the steel ball 60 on the annular inclined surface 221 is released. When the steel ball 60 does not apply an axially inward downward pressure to the annular inclined surface 221, the clamping mechanism can be lifted vertically, and the steel ball 60 is pressed into the accommodating notch 406 through the annular inclined surface 221 configured on the pull stud 20 of the clamping mechanism, so that the pull stud 20 can be pulled out of the shaft sleeve 70 vertically.

Two sealing rings 402 arranged in an inner concentric circle and an outer concentric circle are arranged at the bottom of the positioning seat body 401 to ensure the air tightness between the positioning seat body 401 and the base 50. At the same time, a ring of sealing ring 405 is also provided at the annular end of the sleeve 70 to ensure good air tightness between the sleeve 70 and the base 50. A sealing ring 409 is embedded in the inner wall surface of the cylinder 41 close to the shaft sleeve 70, and two rings of sealing rings 403 are embedded in the outer wall surface of the cylinder 41 attached to the positioning seat body 401. Meanwhile, a sealing ring 408 is embedded on the top of the shaft sleeve 70 and close to the outer side surface of the positioning seat body 401, and a sealing ring 407 is arranged between the top of the shaft sleeve 70 and the blind rivet 20 to play a role in preventing dust and slag.

Meanwhile, as shown in fig. 8 and 11, in the present embodiment, the side portion of the flange 22 is attached to the inner wall surface of the shaft sleeve 70, the bottom of the rivet 20 is formed with a hexagonal blind hole 27, the position of the rivet 20 in the vertical direction in the shaft sleeve 70 is adjusted by rotating the rivet 20, and the sum of the depth of the accommodating notch 406, the thickness of the shaft sleeve 70 and the depth of the groove 21 is greater than the diameter of the steel ball 60. The side of the base 50 is provided with a second air hole 52, the bottom of the positioning column 81 forms a circular positioning surface 811, the bottom of the positioning groove 400 forms an air suction hole 48 communicated with the second air hole 52, the positioning column 81 is partially embedded in the positioning groove 400 and covers the air suction hole 48 through the positioning surface 811, and the second air hole 52 is connected with an air generating device. The air generating device may be a vacuum generating device or an air tightness detecting device. For example, when the second air hole 52 is connected to the air tightness detecting device through a quick coupling, the positioning surface 811 can cover the air suction hole 48 to determine whether the clamping mechanism is fixed on the positioning seat 40 in an absolutely horizontal posture, and the air suction hole 48 is completely blocked. The clamping mechanism for clamping the workpiece A is ensured to keep an absolute horizontal posture, and the clamping mechanism has a decisive technical significance on the machining precision of the workpiece A. Specifically, in the present embodiment, the second air hole 52 is communicated with the channel 521 disposed inside the base 50, and the channel 521 passes through the vertical upward channel 522 disposed inside the positioning socket body 401, the horizontal channel 523 and the channel 524 having a diameter significantly smaller than that of the channel 523 or the channel 522, so as to be communicated with the air suction hole 48 disposed at the bottom of the positioning socket 400 through the channel 524.

For a specific implementation scheme of the clamping mechanism included in the fast-assembling positioning fixture in this embodiment, please refer to the description of the first embodiment, which is not described herein again.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A clamping mechanism for clamping a workpiece, the clamping mechanism comprising:

the positioning fixture comprises a positioning fixture (30), a pressing block (10) which transversely clamps a workpiece together with the positioning fixture (30), a positioning sheet (80) which is arranged at the bottom of the positioning fixture (30) and is square, and a blind rivet (20) which is partially arranged in the positioning fixture (30) and vertically penetrates through the positioning sheet (80) downwards, wherein a circle of groove (21) is annularly arranged on the side part of the blind rivet (20), the positioning fixture (30) forms a containing blind hole (18) with threads, and the blind hole (18) is in threaded connection with the top of the blind rivet (20);

the clamping device is characterized in that a first through hole transversely penetrating through the clamping block (10) is formed in the clamping block (10), a screw transversely penetrates through the first through hole and is connected with a positioning clamp (30), the bottom of a workpiece is jointly and transversely clamped through the positioning clamp (30) and the clamping block (10), four positioning columns (81) are vertically and convexly formed in four corners of each positioning sheet (80), first positioning holes (82) which are orthogonally arranged in a cross shape are formed in the positioning sheets (80), and the positioning clamp (30) forms a positioning blind hole (15) matched with the first positioning holes (82).

2. The clamping mechanism according to claim 1, characterized in that the top of the positioning clamp (30) forms a receiving portion (301) for receiving the workpiece, and the lateral side of the receiving portion (301) forms an opening portion (302), and the pressing block (10) is transversely arranged at the opening portion (302) so as to clamp the bottom of the workpiece laterally by the positioning clamp (30) and the pressing block (10) together.

3. Clamping mechanism according to claim 1, characterized in that the side of the positioning clamp (30) houses a sensor (31).

4. The clamping mechanism according to claim 3, wherein a first limiting groove (13) is formed in the bottom of the positioning clamp (30), a second limiting groove (12) is formed in the bottom of the pressing block (10), the first limiting groove (13) and the second limiting groove (12) are oppositely arranged, the extending direction of the first limiting groove (13) is perpendicular to the extending direction of the second limiting groove (12), and the first limiting groove (13) forms a positioning notch (131);

two second positioning holes (14) which are oppositely arranged are formed in the bottom of the positioning clamp (30);

the positioning notch (131), the second limiting groove (12) and the two second positioning holes (14) are arranged in a cross-shaped orthogonal mode relative to the blind rivet (20).

5. Clamping mechanism according to claim 1, characterized in that the top of the groove (21) forms three consecutive adjacent rectangular planes and one arc-shaped plane;

wherein a rectangular plane located in the middle is arranged facing the holding-down block (10).

6. A quick-assembly positioning fixture, characterized in that it comprises a clamping mechanism as claimed in any one of claims 1 to 5, and

the positioning seat (40), a base (50) connected with the positioning seat (40), a cylinder (41), a spring (88) and a steel ball (60);

wherein,

four prism positioning teeth (49) which are arranged in a cross-shaped orthogonal manner and four positioning grooves (400) which are arranged in a cross-shaped orthogonal manner and are used for partially accommodating positioning columns (81) are arranged at the top of the positioning seat (40), and the prism positioning teeth (49) and the positioning grooves (400) are uniformly arranged at intervals in an annular manner;

the positioning seat (40) comprises a positioning seat body (401) and a shaft sleeve (70) which is arranged in the positioning seat body (401) and used for accommodating the blind rivet (20), a plurality of cylinders (41) are arranged between the shaft sleeve (70) and the positioning seat body (401) in an annular axial symmetry mode, a lower blind hole (411) is formed by the cylinders (41), an upper blind hole (404) is formed by the positioning seat body (401), the lower blind hole (411) and the upper blind hole (404) jointly accommodate the end parts of two ends of the spring (88), and a second through hole (701) for accommodating the steel ball (60) is formed by the shaft sleeve (70);

the side of the base (50) is provided with a first air hole (51), the bottom of the base (50) is provided with a hollow channel (53), the air cylinder (41) moves up and down under the driving of air, and pushes the steel ball (60) and is clamped into the groove (21) of the blind rivet (20) when the air cylinder (41) moves down, so that the movement of the blind rivet (20) in the vertical direction is limited through the steel ball (60).

7. The quick-assembly positioning fixture as claimed in claim 6, characterized in that the prismatic positioning teeth (49) form a first positioning edge (43) and a second positioning edge (44) which are separated from each other, and the first positioning edge (43) extends through the first positioning hole (82) and partially into the blind positioning hole (15).

8. The quick-assembling positioning fixture according to claim 6, characterized in that the inside of the cylinder (41) is formed with a receiving notch (406), and when the cylinder (41) moves upward, the steel ball (60) is driven by an annular inclined surface (221) formed by a flange (22) at the bottom of the rivet (20) to push the steel ball (60) into the receiving notch (406); when the cylinder (41) moves downwards, the steel ball (60) is pressed into the groove (21) by the cylinder (41) to press the annular inclined surface (221) through the steel ball (60) so as to limit the movement of the blind rivet (20) in the vertical direction.

9. The quick-assembling positioning fixture as claimed in claim 8, characterized in that the side of the flange (22) is fitted to the inner wall surface of the shaft sleeve (70), a hexagonal blind hole (27) is formed at the bottom of the blind rivet (20), the position of the blind rivet (20) in the vertical direction in the shaft sleeve (70) is adjusted by rotating the blind rivet (20), and the sum of the depth of the accommodating notch (406), the thickness of the shaft sleeve (70) and the depth of the groove (21) is greater than the diameter of the steel ball (60).

10. The fast-assembling positioning fixture according to claim 8, characterized in that a second air hole (52) is provided at a side of the base (50), a circular positioning surface (811) is formed at a bottom of the positioning column (81), a suction hole (48) communicated with the second air hole (52) is formed at a bottom of the positioning groove (400), the positioning column (81) is partially embedded in the positioning groove (400) and covers the suction hole (48) through the positioning surface (811), and the second air hole (52) is connected with an air generating device.