A centering grinding fixture

Abstract

This utility model discloses a centering grinding fixture, including a base, a tie rod, a clamping assembly, and a positioning assembly. The base is used to fix it to the machine tool. The tie rod is located inside the base. The clamping assembly is hinged to the base. The positioning assembly includes a lower positioning block and a middle positioning block. The base has an axial thrust part and a positioning hole arranged in sequence. The positioning hole is coaxial with the base. The lower positioning block is mounted on the base and has a positioning outer circle. The positioning outer circle is interference-fitted with the positioning hole and is coaxially arranged. The middle positioning block is located on the lower positioning block and has a V-shaped positioning groove. The V-shaped positioning groove is used to cooperate with the V-shaped positioning part on the workpiece for positioning. The intersection of the mid-plane of the workpiece thickness and the angle bisector of the V-shaped positioning part is located on the central axis of the positioning outer circle, which drives the clamping assembly to swing and press the workpiece onto the lower positioning block. This utility model has the advantages of high rotational accuracy, easy automatic clamping and loading / unloading, and improved processing efficiency.

Description

Technical Field

[0001] This utility model relates to the field of metal cutting technology, specifically to a centering grinding fixture. Background Technology

[0002] In CNC insert manufacturing, single-piece V-shaped locating inserts, due to their structure, undergo the same edge-grinding process as integral milling cutters. This results in high requirements for the rotational accuracy of the clamping fixture. Traditional hydraulic or spring collets cannot directly clamp such products. Therefore, single-piece V-shaped locating inserts are often mounted on a machining shank during edge grinding, mimicking the machining method of integral milling cutters to ensure the symmetry and rotational accuracy of the insert's edge. After being positioned on the shank, these inserts are clamped using screws, which cannot achieve automatic clamping or automatic loading / unloading. Furthermore, manual clamping of the inserts results in low clamping accuracy, leading to large dimensional runout and low production yield. The clamping force varies from person to person, compromising clamping stability. Frequent tightening and loosening can cause slippage of the clamping attachment's threads, leading to failure. The inability to automatically load and unload products prevents timely insert replacement during continuous machining, resulting in high labor intensity for operators, high processing costs, and low production efficiency. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a centering grinding fixture with high rotational accuracy, easy automatic clamping and loading / unloading, and improved processing efficiency.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A centering grinding fixture includes a base, a pull rod, a clamping assembly, and a positioning assembly. The base is used to fix the fixture to a machine tool. The pull rod is disposed within the base. The clamping assembly is hinged to the base. The positioning assembly includes a lower positioning block and a middle positioning block. An axial thrust portion and a positioning hole are sequentially provided on the base. The positioning hole is coaxial with the base. The lower positioning block is mounted on the base and has a positioning outer circle. The positioning outer circle is interference-fitted with the positioning hole and is coaxially arranged. The middle positioning block is disposed on the lower positioning block and has a V-shaped positioning groove. The V-shaped positioning groove is used to cooperate with a V-shaped positioning portion on the workpiece for positioning. The intersection of the mid-plane of the workpiece thickness and the angle bisector of the V-shaped positioning portion is located on the central axis of the positioning outer circle. One end of the pull rod is connected to a machine tool actuator that can drive the pull rod to reciprocate linearly. The other end of the pull rod is connected to the clamping assembly to drive the clamping assembly to swing and clamp the workpiece onto the lower positioning block.

[0005] As a further improvement to the above technical solution: The diameter of the outer positioning circle is set to D1, the thickness of the workpiece is set to L1, the lower positioning block is provided with a limiting part and a mounting part, the mounting part is used to install the middle positioning block and the workpiece, the limiting part is used to limit the middle positioning block, the distance from the contact surface between the mounting part and the workpiece to the rotation center axis C of the base is set to L2, the vertical distance from the contact surface to the outer positioning circle is set to L3, and the distance from the contact surface between the clamping assembly and the workpiece to the rotation center axis C of the base is set to L4. It is necessary to satisfy: L2 = L4 = L1 × 1 / 2, L3 = D2 × 1 / 2 - L2.

[0006] The limiting part is provided with a first end face positioning surface and a second end face positioning surface at both ends. The first end face positioning surface is used to abut against the axial thrust part, and the second end face positioning surface is used to abut against one end of the middle positioning block. The V-shaped positioning groove is located at the other end of the middle positioning block. Both the first end face positioning surface and the second end face positioning surface are perpendicular to the central axis of the positioning outer circle.

[0007] The lower positioning block is provided with a central positioning pin hole. The central axis of the central positioning pin hole intersects and is perpendicular to the central axis of the positioning outer circle. A central positioning pin shaft is provided inside the central positioning pin hole. The second end face positioning surface and the middle positioning block are both provided with positioning grooves for installing the central positioning pin shaft.

[0008] The included angle of the V-shaped positioning part of the workpiece is α, and the included angle of the V-shaped positioning groove is β. α should satisfy α=β, and the V-shaped positioning groove and the positioning groove on the middle positioning block should be symmetrical about the same center of symmetry.

[0009] The base is provided with a positioning outer circular surface and a limiting end face that match the machine tool spindle interface. The base is also provided with a plurality of connecting holes for connecting to the machine tool spindle interface and a plurality of leveling holes for adjusting the runout of the end face. The central axes of the plurality of connecting holes and the plurality of leveling holes are all perpendicular to the limiting end face.

[0010] The multiple connecting holes and the multiple leveling holes are arranged alternately and evenly along the circumference of the base.

[0011] The clamping assembly includes a clamping seat and a clamping block disposed on the clamping seat. The clamping seat is hinged to the base, and the clamping block is used to clamp and abut against the workpiece.

[0012] The base is provided with two symmetrical support arms, and the clamping seat is hinged between the two support arms. The outer side of the support arm is provided with a correction plane, and the abutment surface and the central axis of the hinge hole of the support arm and the clamping seat are perpendicular to the correction plane.

[0013] The pull rod includes a ball head, a tail connector, and a shaft located between the two. The diameter of the shaft is smaller than the diameter of the ball head. The clamping assembly has an arc groove that can accommodate the ball head. The side of the arc groove facing the base has a connecting straight groove that is adapted to the shaft. The ball head is inside the arc groove, and the shaft passes through the connecting straight groove.

[0014] Compared with the prior art, the advantages of this utility model are: This utility model discloses a centering grinding fixture that positions the workpiece using a positioning component. A pull rod connects to an actuator that drives a clamping component to swing, thus clamping the workpiece. When used in conjunction with a robotic arm, it enables automatic loading and unloading of workpieces for continuous production. The fixture is reliable and highly automated. The positioning component consists of a lower positioning block and a middle positioning block for easy manufacturing and disassembly. V-shaped positioning grooves on the lower and middle positioning blocks engage with V-shaped positioning parts on the workpiece to position it. An axial thrust part and a positioning hole are provided on the base. The lower positioning block has a positioning outer circle that is interference-fitted with it, ensuring that the positioning outer circle and the positioning hole are coaxial. Since the positioning hole is coaxial with the base, the positioning outer circle and the base are also coaxial. The intersection of the workpiece's thickness midline and the angle bisector of the V-shaped positioning part is located on the central axis of the positioning outer circle. Therefore, the workpiece's rotation center coincides with the rotation center of the positioning outer circle, the positioning hole, and the base, which is also the rotation center C of the machine tool spindle, ensuring the workpiece's rotational accuracy. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the centering grinding fixture of this utility model.

[0016] Figure 2 This is an exploded view of the centering grinding fixture of this utility model.

[0017] Figure 3 This is a cross-sectional view of the centering grinding fixture of this utility model.

[0018] Figure 4 This is a side view of the centering grinding fixture of this utility model.

[0019] The labels in the diagram represent: 1. Base; 11. Axial thrust section; 12. Positioning hole; 13. Positioning outer circular surface; 14. Limiting end face; 15. Connecting hole; 16. Leveling hole; 17. Support arm; 171. Correction plane; 18. Hinge hole; 2. Tie rod; 21. Ball head; 22. Tail connection section; 23. Shaft section; 3. Clamping assembly; 31. Contact surface; 32. Clamping seat; 33. Clamping block; 34. Arc 35. Connecting straight groove; 4. Positioning component; 41. Lower positioning block; 411. Positioning outer circle; 412. Limiting part; 413. Mounting part; 414. Abutting surface; 415. First end face positioning surface; 416. Second end face positioning surface; 417. Center positioning pin hole; 418. Center positioning pin shaft; 42. Middle positioning block; 421. V-shaped positioning groove; 5. Workpiece; 51. V-shaped positioning part; 7. Positioning groove. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] Figures 1 to 4This invention illustrates an embodiment of a centering grinding fixture. The centering grinding fixture of this embodiment includes a base 1, a pull rod 2, a clamping assembly 3, and a positioning assembly 4. The base 1 is used to fix the fixture to a machine tool. The pull rod 2 is disposed within the base 1. The clamping assembly 3 is hinged to the base 1. The positioning assembly 4 includes a lower positioning block 41 and a middle positioning block 42. An axial thrust portion 11 and a positioning hole 12 are sequentially provided on the base 1. The positioning hole 12 is coaxial with the base 1. The lower positioning block 41 is mounted on the base 1 and has a positioning outer circle 411. The positioning outer circle 411 is aligned with the positioning outer circle 42. The positioning hole 12 is interference-fitted and coaxially arranged. The middle positioning block 42 is located on the lower positioning block 41. The middle positioning block 42 is provided with a V-shaped positioning groove 421. The V-shaped positioning groove 421 is used to cooperate with the V-shaped positioning part 51 on the workpiece 5 for positioning. The intersection of the mid-section of the thickness of the workpiece 5 and the angle bisector of the V-shaped positioning part 51 is located on the central axis of the positioning outer circle 411. One end of the pull rod 2 is connected to the machine tool actuator that can drive the pull rod 2 to reciprocate linear motion. The other end of the pull rod 2 is connected to the clamping assembly 3 so as to drive the clamping assembly 3 to swing and press the workpiece 5 onto the lower positioning block 41.

[0025] This centering grinding fixture positions the workpiece 5 via the positioning component 4. A pull rod 2 connects to the actuator, driving the clamping component 3 to swing and clamp the workpiece 5. When used in conjunction with a robotic arm, it enables automatic loading and unloading of the workpiece 5 for continuous production. The fixture is reliable and highly automated. The positioning component 4 is equipped with a lower positioning block 41 and a middle positioning block 42 for easy manufacturing and disassembly. The V-shaped positioning grooves 421 on the lower and middle positioning blocks 41 and 42 engage with the V-shaped positioning part 51 on the workpiece 5 to position it. An axial thrust part 11 and a positioning... Hole 12, lower positioning block 41 is provided with positioning outer circle 411, positioning outer circle 411 and lower positioning block 41 are interference fit to ensure that positioning outer circle 411 and positioning hole 12 are arranged coaxially. Since positioning hole 12 is coaxial with base 1, positioning outer circle 411 and base 1 are also coaxial. The intersection of the mid-section of the thickness of workpiece 5 and the angle bisector of V-shaped positioning part 51 is located on the central axis of positioning outer circle 411. Therefore, the rotation center of workpiece 5 coincides with the rotation center of positioning outer circle, positioning hole 12 and base 1, that is, the rotation center C of machine tool spindle coincides with the rotation center of machine tool spindle, ensuring the rotation accuracy of workpiece 5.

[0026] Furthermore, such as Figure 3 and Figure 4As shown, in this embodiment, the diameter of the positioning outer circle 411 is set to D1, the thickness of the workpiece 5 is set to L1, and the lower positioning block 41 is provided with a limiting part 412 and a mounting part 413. The mounting part 413 is used to install the positioning block 42 and the workpiece 5, and the limiting part 412 is used to limit the positioning block 42. The distance from the contact surface 414 between the mounting part 413 and the workpiece 5 to the rotation center axis C of the base 1 is set to L2, the vertical distance from the contact surface 414 to the positioning outer circle 411 is set to L3, and the distance from the contact surface 31 between the clamping component 3 and the workpiece 5 to the rotation center axis C of the base 1 is set to L4. It is necessary to satisfy: L2 = L4 = L1 × 1 / 2, L3 = D2 × 1 / 2 - L2. Dimensions L2 and L3 ensure that the thickness dividing surface of the workpiece 5 is in the same plane as the rotation center C, thereby ensuring rotation accuracy. Dimension L4 ensures that the contact area of ​​the contact surface 31 is maximized when clamping the workpiece 5, ensuring the clamping effect.

[0027] Furthermore, in this embodiment, the limiting part 412 is provided with a first end face positioning surface 415 and a second end face positioning surface 416 at both ends. The first end face positioning surface 415 is used to abut against the axial thrust part 11, and the second end face positioning surface 416 is used to abut against one end of the middle positioning block 42. The V-shaped positioning groove 421 is located at the other end of the middle positioning block 42. Both the first end face positioning surface 415 and the second end face positioning surface 416 are perpendicular to the central axis of the positioning outer circle 411. The first positioning end face 415 is used for axial limiting installation of the lower positioning block 41 on the base 1, and the second end face positioning surface 416 is used for axial limiting installation of the middle positioning block 42 on the lower positioning block 41, which further facilitates the installation and positioning of the workpiece 5.

[0028] Furthermore, in this embodiment, the lower positioning block 41 is provided with a central positioning pin hole 417, the central axis of which intersects and is perpendicular to the central axis of the positioning outer circle 411. A central positioning pin 418 is provided inside the central positioning pin hole 417. Both the second end face positioning surface 416 and the middle positioning block 42 are provided with positioning grooves 7 for installing the central positioning pin 418. This facilitates the centering of the middle block 42 and further ensures the positioning accuracy of the workpiece 5.

[0029] Furthermore, in this embodiment, the included angle of the V-shaped positioning part 51 of the workpiece 5 is α, and the included angle of the V-shaped positioning groove 421 is β, which should satisfy α=β, and the V-shaped positioning groove 421 and the positioning groove 7 on the middle positioning block 42 are symmetrical about the same center of symmetry. This facilitates the centering of the workpiece 5 and ensures the rotational accuracy of the workpiece 5.

[0030] Furthermore, in this embodiment, the base 1 is provided with a positioning outer cylindrical surface 13 and a limiting end face 14 that match the machine tool spindle interface. The base 1 also has multiple connecting holes 15 for connecting to the machine tool spindle interface and multiple leveling holes 16 for adjusting the runout of the end face. The central axes of the multiple connecting holes 15 and the multiple leveling holes 16 are all perpendicular to the limiting end face 14. The base 1 is connected to the machine tool spindle through the connecting holes 15 and the runout of the end face is adjusted through the leveling holes 16 to ensure stability and rotational accuracy during machining. Preferably, the connecting holes 15 are countersunk bolt holes, and the leveling holes 16 are threaded holes.

[0031] Furthermore, in this embodiment, the multiple connecting holes 15 and multiple leveling holes 16 are arranged alternately and evenly along the circumference of the base 1. This facilitates leveling according to the installation conditions and ensures the leveling effect.

[0032] Furthermore, in this embodiment, the clamping assembly 3 includes a clamping seat 32 and a clamping block 33 disposed on the clamping seat 32. The clamping seat 32 is hinged to the base 1, and the clamping block 33 is used to clamp and abut against the workpiece 5. This facilitates the manufacture and replacement of the clamping block 33.

[0033] Furthermore, in this embodiment, the base 1 is provided with two symmetrical support arms 17, and the clamping seat 32 is hinged between the two support arms 17. The outer side of the support arm 17 is provided with a correction plane 171, and the central axis of the contact surface 414 and the hinge hole 18 of the support arm 17 and the clamping seat 32 is perpendicular to the correction plane 171. This ensures the contact area between the contact surface 31 and the workpiece 5 and improves the clamping effect.

[0034] Furthermore, in this embodiment, the pull rod 2 includes a ball head 21, a tail connector 22, and a shaft 23 disposed between the two. The diameter of the shaft 23 is smaller than the diameter of the ball head 21. The clamping assembly 3 is provided with an arc groove 34 that can accommodate the ball head 21. The side of the arc groove 34 facing the base 1 is provided with a connecting straight groove 35 that is adapted to the shaft 23. The ball head 21 is located in the arc groove 34, and the shaft 23 passes through the connecting straight groove 35. The reciprocating motion of the pull rod 2 is converted into the oscillation of the clamping assembly 3 to achieve the clamping and releasing of the workpiece 5, which is conducive to the realization of automated loading and unloading.

[0035] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, should fall within the protection scope of the present invention.

Claims

1. A centerless grinding fixture, characterized by: The assembly includes a base (1), a tie rod (2), a clamping assembly (3), and a positioning assembly (4). The base (1) is used to fix the machine tool. The tie rod (2) is located inside the base (1). The clamping assembly (3) is hinged to the base (1). The positioning assembly (4) includes a lower positioning block (41) and a middle positioning block (42). The base (1) is provided with an axial thrust part (11) and a positioning hole (12) in sequence. The positioning hole (12) is coaxial with the base (1). The lower positioning block (41) is installed on the base (1) and has a positioning outer circle (411). The positioning outer circle (411) is interference-fitted with the positioning hole (12). And coaxial arrangement, the middle positioning block (42) is set on the lower positioning block (41), the middle positioning block (42) is provided with a V-shaped positioning groove (421), the V-shaped positioning groove (421) is used to cooperate with the V-shaped positioning part (51) on the workpiece (5) for positioning, the intersection of the mid-plane of the thickness of the workpiece (5) and the angle bisector of the V-shaped positioning part (51) is located on the central axis of the positioning outer circle (411), one end of the pull rod (2) is connected to the machine tool execution mechanism that can drive the pull rod (2) to reciprocate linear motion, and the other end of the pull rod (2) is connected to the clamping assembly (3) to drive the clamping assembly (3) to swing and press the workpiece (5) on the lower positioning block (41).

2. The centerless grinding fixture of claim 1, wherein: The diameter of the positioning outer circle (411) is set to D1, the thickness of the workpiece (5) is set to L1, the lower positioning block (41) is provided with a limiting part (412) and a mounting part (413), the mounting part (413) is used to install the middle positioning block (42) and the workpiece (5), the limiting part (412) is used to limit the middle positioning block (42), the distance from the contact surface (414) between the mounting part (413) and the workpiece (5) to the rotation center axis C of the base (1) is set to L2, the vertical distance from the contact surface (414) to the positioning outer circle (411) is set to L3, the distance from the contact surface (31) between the clamping component (3) and the workpiece (5) to the rotation center axis C of the base (1) is set to L4, which must satisfy: L2 = L4 = L1 × 1 / 2, L3 = D2 × 1 / 2 - L2.

3. The centerless grinding fixture of claim 2, wherein: The limiting part (412) is provided with a first end face positioning surface (415) and a second end face positioning surface (416) at both ends. The first end face positioning surface (415) is used to abut against the axial thrust part (11), and the second end face positioning surface (416) is used to abut against one end of the middle positioning block (42). The V-shaped positioning groove (421) is located at the other end of the middle positioning block (42). The first end face positioning surface (415) and the second end face positioning surface (416) are both perpendicular to the central axis of the positioning outer circle (411).

4. The centerless grinding fixture of claim 3, wherein: The lower positioning block (41) is provided with a central positioning pin hole (417). The central axis of the central positioning pin hole (417) intersects and is perpendicular to the central axis of the positioning outer circle (411). The central positioning pin hole (417) is provided with a central positioning pin shaft (418). The second end face positioning surface (416) and the middle positioning block (42) are both provided with positioning grooves (7) for installing the central positioning pin shaft (418).

5. The centerless grinding fixture of claim 4, wherein: The included angle of the V-shaped positioning part (51) of the workpiece (5) is α, and the included angle of the V-shaped positioning groove (421) is β. α should satisfy β, and the V-shaped positioning groove (421) and the positioning groove (7) on the middle positioning block (42) should be symmetrical about the same center of symmetry.

6. The centerless grinding fixture of any one of claims 1 to 5, wherein: The base (1) is provided with a positioning outer circular surface (13) and a limiting end face (14) that match the machine tool spindle interface. The base (1) is provided with a plurality of connecting holes (15) for connecting to the machine tool spindle interface and a plurality of leveling holes (16) for adjusting the runout of the end face. The central axes of the plurality of connecting holes (15) and the plurality of leveling holes (16) are perpendicular to the limiting end face (14).

7. The centerless grinding fixture of claim 6, wherein: The multiple connecting holes (15) and the multiple leveling holes (16) are arranged in a staggered and uniform manner along the circumference of the base (1).

8. The centerless grinding fixture of any one of claims 2 to 5, wherein: The clamping assembly (3) includes a clamping seat (32) and a clamping block (33) disposed on the clamping seat (32). The clamping seat (32) is hinged to the base (1), and the clamping block (33) is used to clamp and abut against the workpiece (5).

9. The centerless grinding fixture of claim 8, wherein: The base (1) is provided with two symmetrical support arms (17), and the clamping seat (32) is hinged between the two support arms (17). The support arms (17) are provided with a correction plane (171) on their outer side. The abutment surface (414) and the central axis of the support arm (17) and the hinge hole (18) of the clamping seat (32) are perpendicular to the correction plane (171).

10. The centerless grinding fixture of any one of claims 1 to 5, wherein: The pull rod (2) includes a ball head (21), a tail connector (22), and a shaft (23) located between the two. The diameter of the shaft (23) is smaller than the diameter of the ball head (21). The clamping assembly (3) is provided with an arc groove (34) that can accommodate the ball head (21). The side of the arc groove (34) facing the base (1) is provided with a connecting straight groove (35) that is adapted to the shaft (23). The ball head (21) is inside the arc groove (34), and the shaft (23) passes through the connecting straight groove (35).

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