CN112497065B - Self-centering clamp for inner hole machining - Google Patents

Abstract

The invention discloses a self-centering fixture for inner hole machining, comprising a connecting shaft, a positioning seat and a pressing block. The connecting shaft comprises a coaxially arranged shank and a positioning mandrel. The shank is used for connecting with a machine tool and the diameter of the shank is larger than The diameter of the positioning mandrel, one end of the positioning seat is provided with a void hole, and the other end is provided with a mounting groove for mounting the workpiece. The mounting groove includes a V-shaped positioning surface that can be in contact with the V-shaped positioning portion of the workpiece. In the avoidance hole, the positioning mandrel is penetrated in the avoidance hole and is in contact with the V-shaped positioning surface. The positioning mandrel and the positioning seat are locked by a locking piece. The pressing groove is used to press the workpiece in the installation groove, the pressing block is locked on the positioning seat by the fastener, and the distance between the central hole of the workpiece and the V-shaped positioning surface is equal to the positioning mandrel and the V-shaped positioning surface. The distance between the positioning faces. The invention has the advantages of high centering precision, convenient operation, reliable clamping, time-saving and labor-saving when disassembling the workpiece, and high processing efficiency.

Description

A self-centering fixture for inner hole processing

technical field

The invention relates to the field of machining, in particular to a self-centering fixture for inner hole machining.

Background technique

In the field of machining, especially the inner hole machining of CNC inserts, due to the small aperture size and the high dimensional and geometric accuracy requirements of inner hole machining, grinding is required to meet the design requirements. At the same time, the size and shape of CNC products are different. , Generally, it is difficult to align the position of the center of the calibration hole when the inner hole grinding fixture starts processing, the universality of the fixture is not strong, the adjustment of the fixture is time-consuming and labor-intensive, and the operator is labor-intensive. The difficulty of clamping the workpiece restricts the production efficiency, and the repeated positioning accuracy of the product during mass production is not high, resulting in unstable product size and difficult quality assurance. In conclusion, it is difficult to grind small inner holes.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and to provide a self-centering fixture for inner hole processing with high centering accuracy, convenient operation, reliable clamping, time-saving and labor-saving dismounting of workpieces and high processing efficiency.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A self-centering fixture for inner hole processing includes a connecting shaft, a positioning seat and a pressing block, the connecting shaft includes a coaxially arranged shank and a positioning mandrel, the shank is used for connecting with a machine tool and the diameter of the shank is larger than The diameter of the positioning mandrel, one end of the positioning seat is provided with a hollow hole, and the other end is provided with a mounting groove for mounting the workpiece, the mounting groove includes a V-shaped positioning surface that can contact and cooperate with the V-shaped positioning portion of the workpiece, the The V-shaped positioning surface extends into the avoidance hole, the positioning mandrel is inserted into the avoidance hole and is in contact with the V-shaped positioning surface, the positioning mandrel and the positioning seat are locked by a locking member, and the positioning There is a pressing groove on the seat, the pressing groove communicates with the installation groove, the pressing block is arranged in the pressing groove for pressing the workpiece into the installation groove, and the pressing block is locked by a fastener Tightly on the positioning seat, the distance between the central hole of the workpiece and the V-shaped positioning surface is equal to the distance between the positioning mandrel and the V-shaped positioning surface.

As a further improvement of the above technical solution:

The V-shaped positioning surface includes a first side positioning surface and a second side positioning surface, the distance between the center hole of the workpiece and the first side positioning surface is L1, and the distance between the center hole of the workpiece and the second side positioning surface is L1. The distance is L2, L1=L2, the distance between the positioning mandrel and the first side positioning surface is R1, the distance between the positioning mandrel and the second side positioning surface is R2, R1=R2=L1=L2 .

The V-shaped positioning surface includes a first side positioning surface and a second side positioning surface, the distance between the center hole of the workpiece and the first side positioning surface is L1, and the distance between the center hole of the workpiece and the second side positioning surface is L1. The distance is L2, L1≠L2, the distance between the positioning mandrel and the first side positioning surface is R1, the distance between the positioning mandrel and the second side positioning surface is R2, R1≠R2, R1=L1, R2=L2 .

The installation groove also includes an axial positioning surface, the workpiece abuts on the axial positioning surface, and the axial positioning surface is provided with an avoidance hole coinciding with the central hole of the workpiece in the axial direction; There is an inner cooling hole penetrating the shank and the positioning mandrel, and the inner cooling hole communicates with the escape hole.

The pressing groove includes a bottom surface of the pressing groove and two side surfaces of the pressing groove, and an angle γ is formed between the bottom surface of the pressing groove and the axis C of the connecting shaft, 0<γ<90°.

A plane portion is arranged on the outer peripheral surface of the positioning seat, the pressing groove is arranged on the plane portion, and the side surface of the pressing groove is perpendicular to the plane portion and the axial positioning surface, and the three intersect.

The flat portion is provided with a first locking hole, the positioning mandrel is provided with a second locking hole, and the locking piece is arranged in the first locking hole and the second locking hole.

A scale marking line corresponding to the position of the second locking hole is provided on the stepped surface between the handle and the positioning mandrel.

The included angle of the V-shaped positioning surface is α, and the included angle of the V-shaped positioning portion of the workpiece is β, 20°<α=β<180.

The fastener is a stud bolt, the pressure block is provided with a first threaded hole matched with the stud bolt, the positioning seat is provided with a second threaded hole matched with the stud bolt, the first threaded hole The screw hole and the second screw hole have opposite directions of rotation; the pressing surface of the pressing block in contact with the workpiece is parallel to the horizontal plane.

Compared with the prior art, the advantages of the present invention are:

The self-centering fixture for inner hole machining of the present invention can ensure that the center hole of the workpiece and the rotation center of the spindle are completely coincident, so that the center hole of the workpiece can be processed quickly and accurately without aligning the inner hole (center hole) of the workpiece. The inner hole center of the product is processed. The positioning mandrel is in contact with the V-shaped positioning surface, and the workpiece is in contact with the V-shaped positioning surface, that is, the positioning mandrel and the workpiece are in contact with the same V-shaped positioning surface, so as to realize the rapid installation of the workpiece and the high-precision positioning of the workpiece. Self-centering effect; the change of the radius of the outer surface of the positioning mandrel adapts to the hole positioning and processing of different central hole positions of different products, with high centering accuracy, convenient operation, reliable clamping, time-saving and labor-saving when disassembling the workpiece, and processing efficiency high advantage.

Description of drawings

FIG. 1 is an exploded schematic diagram of the three-dimensional structure of a self-centering fixture for inner hole processing according to Embodiment 1 of the present invention.

FIG. 2 is a schematic front view of the structure of the self-centering fixture for inner hole processing according to Embodiment 1 of the present invention.

FIG. 3 is a schematic diagram of the axial structure of the inner hole machining self-centering jig according to Embodiment 1 of the present invention.

FIG. 4 is a schematic three-dimensional structure diagram of a positioning seat in Embodiment 1 of the present invention.

FIG. 5 is a schematic front view of the structure of the positioning seat in Embodiment 1 of the present invention.

FIG. 6 is a schematic three-dimensional structure diagram of a connecting shaft in Embodiment 2 of the present invention.

FIG. 7 is a schematic front view of the structure of the connecting shaft in Embodiment 2 of the present invention.

8 is a schematic diagram of the axial structure of the connecting shaft in Embodiment 2 of the present invention.

The symbols in the figure represent:

1. Shank; 11. Step surface; 12. Scale marking line; 13. Inner cooling hole; 2. Positioning mandrel; 21. Second locking hole; 3. Positioning seat; 31. Evacuation hole; 32. Pressure Tightening groove; 321, bottom surface of pressure groove; 322, side surface of pressure groove; 33, flat surface; 331, first locking hole; 34, second threaded hole; 35, limit end face; 4, pressing block; 41, first Threaded hole; 42, pressing surface; 5, workpiece; 51, V-shaped positioning part; 52, central hole; 6, installation groove; 61, V-shaped positioning surface; 611, first side positioning surface; 612, second side Positioning surface; 62. Axial positioning surface; 621. Avoidance hole; 7. Locking piece; 8. Fastener.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

As shown in Figures 1 to 5, the inner hole machining self-centering fixture in this embodiment includes a connecting shaft, a positioning seat 3 and a pressing block 4. The connecting shaft includes a coaxially arranged shank 1 and a positioning mandrel 2. The shank The part 1 is used to connect with the machine tool, the diameter of the shank 1 is larger than the diameter of the positioning mandrel 2, one end of the positioning seat 3 is provided with an escape hole 31, and the other end is provided with a mounting groove 6 for mounting the workpiece 5, and the mounting groove 6 includes The V-shaped positioning portion 51 of 5 is in contact with the V-shaped positioning surface 61, the V-shaped positioning surface 61 extends into the hollow hole 31, and the positioning mandrel 2 passes through the hollow hole 31 and is in contact with the V-shaped positioning surface 61. , the positioning mandrel 2 and the positioning seat 3 are locked by the locking member 7, the positioning seat 3 is provided with a pressing groove 32, the pressing groove 32 communicates with the installation groove 6, and the pressing block 4 is arranged in the pressing groove 32 for Press the workpiece 5 into the installation groove 6, the pressing block 4 is locked on the positioning seat 3 by the fastener 8, and the distance between the central hole 52 of the workpiece 5 and the V-shaped positioning surface 61 is equal to the positioning mandrel 2 and the V-shaped positioning surface 61. distance between the positioning surfaces 61.

During installation, insert the positioning mandrel 2 into the hollow hole 31 of the positioning seat 3, so that the positioning mandrel 2 is in contact with the V-shaped positioning surface 61, and the positioning seat 3 and the positioning mandrel 2 are pre-tightened by the locking member 7, The workpiece 5 is placed in the installation groove 6, the V-shaped positioning portion 51 at the lower end of the workpiece 5 is in contact with the V-shaped positioning surface 61 in the installation groove 6, and the pressing block 4 is placed in the pressing groove 32 on the positioning seat 3, The pressing block 4 is pressed on the workpiece 5, and is pre-tightened on the positioning seat 3 by the fastener 8. Finally, the positions of the positioning seat 3 and the workpiece 5 are adjusted, and the locking member 7 and the fastener 8 are tightened to complete the clamping. Install. Since the V-shaped positioning surface 61 cooperates with the outer circular surface of the positioning mandrel 2, the radius of the outer circular surface of the positioning mandrel 2 is equal to the distance from the V-shaped positioning portion 51 of the workpiece 5 to the central hole 52, so that the central hole 52 of the workpiece 5 is equal to the distance from the central hole 52 of the workpiece 5. The positioning mandrel 2 is coaxial, and at the same time, the positioning mandrel 2 is coaxial with the handle 1, and the handle 1 is connected with the main shaft of the machine tool performing rotary motion, that is, when the machine tool spindle rotates, the center hole 52 of the workpiece 5 always coincides with the center of the machine tool spindle. The V-shaped positioning surface 61 realizes the self-centering of the workpiece 5, ensures the machining accuracy, and has high repeated positioning accuracy.

The inner hole machining self-centering fixture can ensure that the center hole 52 of the workpiece 5 completely coincides with the rotation center of the spindle, so that the center hole of the workpiece 5 can be processed quickly and accurately without aligning the inner hole (center hole 52) of the workpiece. Process the inner hole center of the processed product. The positioning mandrel 2 is in contact with the V-shaped positioning surface 61, and the workpiece 5 is in contact with the V-shaped positioning surface 61, that is, the positioning mandrel 2 and the workpiece are in contact with the same V-shaped positioning surface 61 to realize the rapid installation of the workpiece 5. The high-precision positioning of the workpiece 5 achieves the self-centering effect. The change of the radius of the outer circular surface of the positioning mandrel 2 is suitable for the hole positioning and processing of different central hole positions of different products, and has the advantages of high centering accuracy, convenient operation, reliable clamping, time-saving and labor-saving disassembly of the workpiece, and high processing efficiency.

In this embodiment, the shank 1 has an outer circular interface, which is connected to the spindle of the machine tool, and the outer circular interface is of standard size. The diameter of the outer circular interface is the same as that of the shank 1. The V-shaped positioning surface 61 penetrates through the hollow hole 31 , that is, the axial length of the inner V-shaped positioning surface 61 of the hollow hole 31 is equal to the axial length of the hollow hole 31 . In other embodiments, the diameters of the outer circular interface and the handle portion 1 may also be different. The V-shaped positioning surface 61 may also extend into the avoidance hole 31 , but does not penetrate through the avoidance hole 31 .

In this embodiment, the V-shaped positioning surface 61 includes a first side positioning surface 611 and a second side positioning surface 612, the distance between the center hole 52 of the workpiece 5 and the first side positioning surface 611 is L1, and the center hole 52 of the workpiece 5 The distance from the second side positioning surface 612 is L2, L1=L2, the distance between the positioning mandrel 2 and the first side positioning surface 611 is R1 respectively, and the distance between the positioning mandrel 2 and the second side positioning surface 612 is R2, R1=R2=L1=L2.

In this embodiment, the stepped surface 11 between the shank 1 and the positioning mandrel 2 is in contact with the limiting end surface 35 at the corresponding end of the positioning seat 3 to achieve axial positioning. The positioning mandrel 2 is in contact with the V-shaped positioning surface 61 to achieve radial positioning, thereby improving the positioning accuracy of the positioning mandrel 2 and the positioning seat 3. The installation groove 6 also includes an axial positioning surface 62, and the workpiece 5 abuts against the axial positioning On the surface 62, the positioning accuracy and reliability of the workpiece 5 are improved.

In the present embodiment, the axial positioning surface 62 is provided with an escape hole 621 which is axially coincident with the center hole 52 of the workpiece 5 , and is used for avoidance when machining the center hole 52 . The connecting shaft is provided with an inner cooling hole 13 penetrating the shank 1 and the positioning mandrel 2 , and the inner cooling hole 13 communicates with the escape hole 621 to realize cooling when the workpiece 5 is machined.

In this embodiment, the pressing groove 32 includes a bottom surface 321 of the pressing groove and two side surfaces 322 of the pressing groove. There is an included angle γ between the bottom surface 321 of the pressing groove and the axis C of the connecting shaft, 0<γ<90°, and the preferred range is 30° <γ<60°, and γ=45° in this embodiment. A plane portion 33 is provided on the outer peripheral surface of the positioning seat 3 , and the pressing groove 32 is provided on the plane portion 33 . The fastener 8 is a stud bolt, the pressure block 4 is provided with a first threaded hole 41 that cooperates with the stud bolt, the positioning seat 3 is provided with a second threaded hole 34 that cooperates with the stud bolt, and the first threaded hole 41 The rotation direction of the second threaded hole 34 is opposite; the pressing surface 42 of the pressing block 4 in contact with the workpiece 5 is parallel to the horizontal plane. Since the angle γ between the bottom surface 321 of the pressure groove and the axis C of the connecting shaft is an acute angle, the stud bolts are arranged obliquely, which on the one hand facilitates the installation of the stud bolts and improves the installation reliability; There is a downward component force, so that the pressing surface 42 presses the workpiece 5 and improves the clamping stability of the workpiece 5 . If the stud is horizontal, the pressing force of the pressing surface 42 on the workpiece 5 is small. If the stud bolt is vertical, the length of the stud bolt in the positioning seat 3 is limited due to the arrangement of the avoidance hole 31, so that the pressing is not firm, and since the workpiece 5 is on one side of the positioning seat 3, It is necessary to set the pressing block 4 to be long to obtain the workpiece. If the setting is too long, the pressed end of the pressing block 4 will easily warp. For this reason, the structure of the inclined stud bolt and the pressure block 4 of the present application can not only compress the workpiece 5, the structure is compact, and the pressure block 4 does not need to be set longer, and at the same time, the stud bolt 5 can be guaranteed to have sufficient tightening force.

In this embodiment, the flat portion 33 of the positioning seat 3 is provided with a first locking hole 331 , the positioning mandrel 2 is provided with a second locking hole 21 , and the locking member 7 is provided in the first locking hole 331 and the second locking hole 331 . inside the locking hole 21. The locking member 7 is a top wire. The stepped surface 11 between the shank 1 and the positioning mandrel 2 is provided with a scale marking line 12 corresponding to the position of the second locking hole 21 . When the positioning mandrel 2 is inserted into the avoidance hole 31, the second locking hole 21 cannot be seen. The locking holes 21 are aligned to facilitate the locking of the top wire.

The included angle of the V-shaped positioning surface 61 is α, and the included angle of the V-shaped positioning portion 51 of the workpiece 5 is β, 20°<α=β<180°. A further preferred range is 90°<α=β<150°, and in this embodiment, α=β=150°.

Example 2

As shown in Figures 6 to 8, the inner hole processing self-centering fixture of this embodiment is different from Embodiment 1 in that:

In this embodiment, the V-shaped positioning surface 61 includes a first side positioning surface 611 and a second side positioning surface 612, the distance between the center hole 52 of the workpiece 5 and the first side positioning surface 611 is L1, and the center hole 52 of the workpiece 5 The distance from the second side positioning surface 612 is L2, L1≠L2, the distance between the positioning mandrel 2 and the first side positioning surface 611 is R1, and the distance between the positioning mandrel 2 and the second side positioning surface 612 is R2, R1≠R2, R1=L1, R2=L2, in order to improve the versatility of the fixture, the distance between the central hole 52 and the V-shaped positioning surface 61 is not equal, the positioning mandrel 2 should be strained into a coaxial stepped outer circular surface, the first side The positioning surface 611 is in contact with the part of the positioning mandrel 2 with a radius of R1, and the second side positioning surface 612 is in contact with the part of the positioning mandrel 2 with a radius of R2, which is equivalent to the positioning mandrel 2 or the V-shaped positioning surface 61. , the V-shaped positioning portion 51 of the workpiece 5 is also in contact with the first side positioning surface 611 and the second side positioning surface 612 to ensure that the center hole 52 of the workpiece 5 is still coaxial with the positioning mandrel 2 .

The remaining points not described are basically the same as those in Embodiment 1, and will not be repeated here.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into an equivalent implementation of equivalent changes. example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention should fall within the protection scope of the technical solutions of the present invention.

Claims (10)

1. An inner hole machining self-centering fixture, characterized in that: it comprises a connecting shaft, a positioning seat (3) and a pressing block (4), and the connecting shaft comprises a coaxially arranged shank (1) and a positioning mandrel (2), the shank (1) is used to connect with the machine tool and the diameter of the shank (1) is larger than the diameter of the positioning mandrel (2). One end is provided with an installation groove (6) for installing the workpiece (5), the installation groove (6) includes a V-shaped positioning surface (61) that can be in contact with the V-shaped positioning portion (52) of the workpiece (5), so The V-shaped positioning surface (61) extends into the avoidance hole (31), the positioning mandrel (2) is penetrated in the avoidance hole (31) and is in contact with the V-shaped positioning surface (61). The positioning mandrel (2) and the positioning seat (3) are locked by the locking piece (7), and the positioning seat (3) is provided with a pressing groove (32), and the pressing groove (32) is connected with the installation groove (6) are connected, the pressing block (4) is arranged in the pressing groove (32) for pressing the workpiece (5) into the installation groove (6), and the pressing block (4) is tightened by tightening the The part (8) is locked on the positioning seat (3), and the distance between the central hole (51) of the workpiece (5) and the V-shaped positioning surface (61) is equal to the positioning mandrel (2) and the V-shaped positioning surface. The distance between (61), the V-shaped positioning surface (61) is matched with the outer circular surface of the positioning mandrel (2), the radius of the outer circular surface of the positioning mandrel (2) and the V-shaped positioning part (52) to the center The distances between the holes (51) are equal, so that the central hole (51) of the workpiece (5) is coaxial with the positioning mandrel (2). 2. The inner hole machining self-centering fixture according to claim 1, wherein the V-shaped positioning surface (61) comprises a first side positioning surface (611) and a second side positioning surface (612), so The distance between the center hole (51) of the workpiece (5) and the first side positioning surface (611) is L1, and the distance between the center hole (51) of the workpiece (5) and the second side positioning surface (612) is L2, L1=L2, the distance between the positioning mandrel (2) and the first side positioning surface (611) is R1 respectively, and the distance between the positioning mandrel (2) and the second side positioning surface (612) is R2, R1=R2=L1=L2. 3. The inner hole machining self-centering fixture according to claim 1, wherein the V-shaped positioning surface (61) comprises a first side positioning surface (611) and a second side positioning surface (612), so The distance between the center hole (51) of the workpiece (5) and the first side positioning surface (611) is L1, and the distance between the center hole (51) of the workpiece (5) and the second side positioning surface (612) is L2, L1≠L2, the distance between the positioning mandrel (2) and the first side positioning surface (611) is R1 respectively, and the distance between the positioning mandrel (2) and the second side positioning surface (612) is R2, R1 ≠R2, R1=L1, R2=L2. 4. The inner hole machining self-centering fixture according to any one of claims 1 to 3, characterized in that: the mounting groove (6) further comprises an axial positioning surface (62), and the workpiece (5) abuts against Relying on the axial positioning surface (62), the axial positioning surface (62) is provided with an escape hole (621) coinciding with the central hole (51) of the workpiece (5) in the axial direction; There is an inner cooling hole (13) penetrating the shank (1) and the positioning mandrel (2), and the inner cooling hole (13) communicates with the escape hole (621). 5. The inner hole machining self-centering fixture according to claim 4, wherein the pressing groove (32) comprises a bottom surface (321) of the pressing groove and two side surfaces (322) of the pressing groove, and the pressing groove (32) There is an included angle γ between the bottom surface (321) and the axis C of the connecting shaft, 0<γ<90°. 6. The inner hole machining self-centering fixture according to claim 5, characterized in that: a plane portion (33) is provided on the upper outer peripheral surface of the positioning seat (3), and the pressing groove (32) is provided in On the plane portion (33), the side surface (322) of the pressing groove is perpendicular to the plane portion (33) and the axial positioning surface (62), and the three intersect. 7. The inner hole machining self-centering fixture according to claim 6, characterized in that: the plane portion (33) is provided with a first locking hole (331), and the positioning mandrel (2) is provided with a first locking hole (331) The second locking hole (21), the locking member (7) is arranged in the first locking hole (331) and the second locking hole (21). 8. The inner hole machining self-centering fixture according to claim 7, characterized in that: the stepped surface (11) between the shank (1) and the positioning mandrel (2) is provided with a second lock The scale marking line (12) corresponding to the position of the tight hole (21). 9. The inner hole machining self-centering fixture according to any one of claims 1 to 3, characterized in that: the included angle of the V-shaped positioning surface (61) is α, and the V-shaped positioning of the workpiece (5) The included angle of the part (52) is β, 20°<α=β<180. 10. The inner hole machining self-centering jig according to any one of claims 1 to 3, wherein the fastener (8) is a stud bolt, and the pressure block (4) is provided with a The first threaded hole (41) matched with the stud bolt, the positioning seat (3) is provided with a second threaded hole (34) matched with the stud bolt, the first threaded hole (41) is connected with the second threaded hole (41) The direction of rotation of the hole (34) is opposite; the pressing surface (42) of the pressing block (4) in contact with the workpiece (5) is parallel to the horizontal plane.

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