A rotary cutting tool axial positioning device

Abstract

This invention is an axial positioning device for a rotary cutting tool, characterized in that it includes a truncated circular platform (1), a spring collet assembly (2), an external diameter micrometer (4), and a connecting device (3); wherein the truncated circular platform (1) is installed on the outer side of the frame (8) of the external diameter micrometer (4) with the anvil, and the anvil of the external diameter micrometer (4) is removed, that is, the truncated circular platform (1) replaces the anvil; this invention can realize the rapid installation and positioning of the cutting tool, and ensure the consistency of product size and shape.

Description

Technical Field

[0001] This invention relates to an axial positioning device for rotary cutting tools, and more particularly to an axial position positioning device for rotary cutting tools such as cylindrical end mills, reamers, countersinks, taps, twist drills, center drills, and reamers used in CNC machine tools and robotic machining equipment. Background Technology

[0002] In mass production machining, CNC equipment and industrial robots are widely used. Their characteristic is that the machining equipment automatically completes the cutting of product elements according to a pre-programmed machining program. Once the machining equipment and program are fixed, the shape and dimensional accuracy of the product are determined by the relative positional accuracy between the product and the cutting tool. If the axial position of the cutting tool changes, it will affect the cutting trajectory, thus causing changes in the shape and size of the product. Therefore, the consistency of the cutting tool's installation position directly determines the machining accuracy of the product.

[0003] Currently, there are two main methods to ensure consistent axial installation position of rotary cutting tools: ① Roughly measure the protruding length of the tool using measuring tools such as vernier depth gauges, then install the tool according to the measured length, and repeatedly test cut to measure any deviations in the tool installation, adjusting the tool position accordingly. ② Use custom-made cutting tools, machining positioning elements on the tool holder to ensure that the tool can only be installed in a fixed position.

[0004] The two methods mentioned above have the following problems: ① The method of calibrating the tool position by trial cutting is complicated, inefficient, and requires high operator skills. Changing a tool takes several hours. To ensure consistent installation position using custom tools, custom tools and corresponding custom fixtures are required. Since the production batch of custom tools and custom fixtures is very small, the manufacturing cost is very high, and the price is often several times that of mass-produced general-purpose tools and fixtures. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an axial positioning device for a rotary cutting tool. It enables rapid installation and positioning of the rotary cutting tool, ensuring the consistency of the tool's axial position, i.e., its extension length.

[0006] An axial positioning device for a rotary cutting tool, characterized in that it includes a counter-rotating circular platform 1, a spring collet assembly 2, an external diameter micrometer 4, and a connecting device 3; wherein the counter-rotating circular platform 1 is installed on the outer side of the frame 8 of the external diameter micrometer 4 with the anvil, and the anvil of the external diameter micrometer 4 is removed, i.e., the counter-rotating circular platform 1 replaces the anvil; the spring collet assembly 2 includes a locking nut 5, an ER spring collet 6, and a collet shank 7, the locking nut 5 and the collet shank 7 are connected by threads, and the ER spring collet 6 is installed in the space enclosed by the locking nut 5 and the collet shank 7. The inner screw is connected to the screw rod on the outer side of the chuck shank 7, and the locking nut 5 is screwed to the outer side of the ER spring collet 6; the spring collet assembly 2 fixes one end of the chuck shank 7 to the end of the outer diameter micrometer 4 frame 8 with the measuring rod 41 through the connecting device 3, and inserts the measuring rod 41 into the round hole in the center of the chuck shank 7; the anvil mounting hole of the outer diameter micrometer 4 is enlarged into a through hole with a diameter slightly larger than the maximum outer diameter of the tool 100 being measured; the round hole in the center of the truncated cone 1, the inner conical surface of the chuck shank 7 of the spring collet assembly 2 and the measuring rod 41 of the outer diameter micrometer 4 are strictly coaxial;

[0007] During operation, loosen the locking nut 5 of the rotary tool positioning device, and push the measuring rod 41 of the outer diameter micrometer 4 to the corresponding position according to the required extension length of the tool, and lock the position of the measuring rod 41; insert the tool 100 to be tested through the alignment truncated cone 1 into the spring collet assembly 2, and ensure that the tool 100 to be tested is in solid contact with the end face of the measuring rod 41, and tighten the locking nut 5; insert the tool holder of the tool 100 to be tested into the machine tool fixture 300, so that the end face of the alignment truncated cone 1 is pressed against and aligned with the end face 301 of the machine tool fixture, and lock the machine tool fixture 300; then remove the rotary tool axial positioning device 400 to ensure that the extension length of the tool 100 to be tested is equal to the specified value.

[0008] The alignment frustum 1 is made of bearing steel GCr15, with a heat treatment hardness of HRC61-66, and the diameter of the central hole is clearance-fitted with the diameter of the test tool 100.

[0009] The chuck shank 7 is made of bearing steel GCr15, heat-treated to a hardness of HRC61-66, and the conical angle of the conical surface of the central conical hole is equal to that of the conical surface of the outer conical surface of the ER spring chuck 6.

[0010] The rotary tool axial positioning device involved in this invention is simple to install and position, and the tool installation position repeatability can reach 0.01mm. It can achieve rapid tool installation and positioning without the need for expensive custom tools and custom fixtures, ensuring the consistency of product size and shape. Attached Figure Description

[0011] Figure 1 A schematic diagram of the structure of the present invention with the test tool 100 installed;

[0012] Figure 2 ,for Figure 1 Enlarged view of the structure at point A in the middle;

[0013] Figure 3 1. Structural diagram of the truncated cone 1 of this invention;

[0014] Figure 4 1. Structural diagram of the chuck handle of this invention;

[0015] Figure 5 The diagram shows the relative positions of the present invention with the machine tool fixture 300 and the test tool 100 during operation.

[0016] Figure 6 ,for Figure 5 Enlarged view of the structure at point B in the middle;

[0017] Wherein, 1 is the alignment truncated cone, 2 is the spring collet assembly, 3 is the connecting device, 4 is the outer diameter micrometer screw gauge, 5 is the locking nut, 6 is the ER spring collet, 7 is the collet shank, 41 is the measuring rod, 100 is the tool to be measured, 300 is the machine tool fixture, 301 is the end face of the machine tool fixture, and 400 is the present invention. Detailed Implementation

[0018] The axial positioning device for a rotating cutting tool consists of an alignment frustum 1, a spring collet assembly 2, an outer diameter micrometer 4, a connecting device 3, and fasteners. The spring collet assembly includes a locking nut 5, an ER spring collet 6, and a collet shank 7, wherein the ER spring collet 6 is located within the space enclosed by the locking nut 5 and the collet shank 7. The specific structure is as follows... Figure 1 , 2 As shown.

[0019] The truncated cone 1 is shaped like a cylinder connected to a U-shaped structure. The cylinder has a hole in its center, slightly larger than the maximum diameter of the tool being measured 100, ensuring a clearance fit between the hole diameter and the diameter of the tool 100. The hole is strictly coaxial with the measuring rod 41 of the micrometer screw gauge 4. This part is used to align the invention with the fixture 300 on the machine tool and is installed on the outer side of the frame 8 of the micrometer screw gauge 1, which has the anvil end. It is made of bearing steel GCr15 with a heat treatment hardness of HRC61-66. The specific structure is as follows... Figure 3 As shown.

[0020] The spring collet assembly 2 is used to grip the tool 100 being calibrated, preventing it from tilting or moving. The locking nut 5 and the ER spring collet 6 are standardized products. The collet shank 7 is shaped like two connected cylinders. The outer surface of the smaller cylinder has threads that mate with the locking nut 5, and the center has a conical hole that mates with the outer conical surface of the ER spring collet 6. The inner conical surface of the conical hole is strictly coaxial with the measuring rod. The structure of the collet shank 7 is as follows... Figure 4As shown. The chuck shank 7 is made of bearing steel GCr15, with a heat treatment hardness of HRC61~66.

[0021] The micrometer 4, used to measure the extension length of the calibrated tool 100, also serves as the frame for the entire positioning device, providing a mounting position for the alignment stage 1 and the spring collet assembly 2. The micrometer 4 requires the following modifications: the anvil is removed, and the anvil mounting hole is enlarged to a through hole with a diameter slightly larger than the maximum outer diameter of the tool being measured; mounting holes and mounting reference surfaces are machined on the ruler 8 for mounting the alignment stage 1 and the spring collet assembly 2.

[0022] The outer diameter micrometer screw gauge 4 and the frame 8 of the counterbalance circular platform 1 are fitted with an interference fit, with a fit accuracy of H7 / p6. The coaxiality accuracy of the circular hole of the counterbalance circular platform 1, the inner conical surface of the chuck shank 7, and the measuring rod 41 of the outer diameter micrometer screw gauge 4 is φ0.08mm. To ensure that the center hole of the counterbalance circular platform 1 and the center conical hole of the chuck shank 7 are coaxial, they are machined after the entire device is fixed.

[0023] How to use the axial positioning device for rotary cutting tools:

[0024] Tool axial position measurement: Loosen the locking nut 5 of the rotary tool positioning device and retract the measuring rod 41 of the external diameter micrometer 4. Insert the tool 100 to be measured into the circular hole at the center of the alignment platform 1, so that the alignment platform 1 is pressed against and aligned with the front end face of the machine tool fixture 300. Lock the locking spring collet assembly 2 to lock the tool 100 firmly, and use the external diameter micrometer 4 to measure the value of the tool extension length.

[0025] Tool axial positioning:

[0026] According to the specified tool extension length, push the measuring rod 41 of the micrometer screw gauge 4 to the corresponding position and lock the measuring rod 41. Insert the tool 100 to be measured into the spring collet assembly 2 from the alignment platform 1, ensuring it is in solid contact with the measuring rod of the micrometer screw gauge 4, and tighten the locking nut 5 to secure the tool 100. Insert the tool shank of the tool 100 into the machine tool fixture 300, ensuring the end face of the alignment platform 1 is flush with and aligned with the end face of the fixture 300, and lock the machine tool fixture 300. Remove the rotary tool positioning device to ensure the tool extension length is equal to the specified value.

[0027] When using the rotary tool axial positioning device, the relative positions of the machine tool fixture 300, the tool 100, and the rotary tool positioning device are as follows: Figure 2 As shown.

[0028] The invention will be illustrated by way of an example.

[0029] An axial positioning device for a cutting tool with a diameter of φ6mm to φ6.5mm and an extension length of 20mm to 45mm is used as an example.

[0030] The outer diameter micrometer is a mechanical type with a measuring range of 0-25mm, an accuracy of not less than 0.01mm, and a frame opening length of ≥40mm.

[0031] Locking nut 5, specification ER11-A-M14×0.75, material is high-strength fastener steel SCM-440, heat treatment hardness HRC41~45.

[0032] ER spring collet 6, specifications are ER11-6~7, accuracy is A grade (within 0.015mm), material is spring steel 65Mn, HRC44~52.

[0033] For the right circular frustum 1, the material is bearing steel GCr15, the heat treatment hardness is HRC61~66, and the diameter of the central circular hole is φ6.6+0.08+0.02mm.

[0034] The chuck is made of bearing steel GCr15 with a heat treatment hardness of HRC61~66; the inner conical surface has a cone angle of 16°±10', a surface profile of φ0.04mm, and a roughness of Ra1.6; the inner conical surface and the outer cylindrical surface are coaxial with a diameter of φ0.06mm; the thread is an M14×0.75 triangular thread with a precision of 6h.

[0035] The outer diameter micrometer was modified by removing the anvil and enlarging the anvil mounting hole to φ6.7±0.04, and reducing the diameter of the measuring rod to φ5.9+0.03.

[0036] The inner conical surface of the chuck handle is coaxial with the measuring rod by φ0.05; the circular hole of the aligning frustum 1 is coaxial with the mounting hole of the measuring anvil by φ0.05.

[0037] The above embodiments can ensure that the axial position accuracy of rotary cutting tools such as cylindrical end mills, reamers, countersinks, taps, twist drills, center drills, and reamers with diameters of φ6mm to φ6.5mm and extension lengths of 20mm to 45mm reaches 0.01mm, and the tool positioning and installation time is only a few minutes.

[0038] This invention relates to an axial positioning device for rotary cutting tools, and more particularly to an axial positioning device for rotary cutting tools such as cylindrical end mills, reamers, countersinks, taps, and drills used in CNC machine tools and robotic machining equipment. The rotary cutting tool axial positioning device consists of an alignment frustum 1, a spring collet assembly 2, an outer diameter micrometer 4, and a connecting device 3. The spring collet assembly 2 includes a locking nut 5, an ER spring collet 6, and a collet shank. The rotary cutting tool axial positioning device offers simple positioning operation, achieving a tool installation position repeatability accuracy of 0.01mm. It eliminates the need for expensive custom-made tools and fixtures, enabling rapid tool installation and positioning, and ensuring consistency in product dimensions and shape.

Claims

1. An axial positioning device for a rotary cutting tool, characterized in that: it includes an alignment frustum (1), a spring collet assembly (2), an outer diameter micrometer screw gauge (4), and a connecting device (3); wherein, The truncated circular platform (1) is installed on the outer side of the frame (8) of the micrometer screw gauge (4) with the anvil, and the anvil of the micrometer screw gauge (4) is removed, that is, the truncated circular platform (1) replaces the anvil; the spring collet assembly (2) includes: a locking nut (5), an ER spring collet (6) and a collet handle (7), the locking nut (5) and the collet handle (7) are connected by threads, the ER spring collet (6) is installed in the space enclosed by the locking nut (5) and the collet handle (7); the locking nut (5) is screwed onto the screw rod on the outer side of the collet handle (7), and the locking nut (5) is screwed... Connected to the outside of the ER spring collet (6); the spring collet assembly (2) fixes one end of the collet shank (7) to the end of the outer diameter micrometer (4) frame (8) with the measuring rod (41) through the connecting device (3), and inserts the measuring rod (41) into the round hole in the center of the collet shank (7); the anvil mounting hole of the outer diameter micrometer (4) is enlarged into a through hole with a diameter slightly larger than the maximum outer diameter of the tool (100) being measured; the round hole in the center of the truncated cone (1), the inner conical surface of the collet shank (7) of the spring collet assembly (2) and the measuring rod (41) of the outer diameter micrometer (4) are strictly coaxial; During operation, loosen the locking nut (5) of the rotary tool positioning device, and push the measuring rod (41) of the outer diameter micrometer (4) to the corresponding position according to the length that the tool should extend, and lock the position of the measuring rod (41); insert the tool (100) to be tested through the alignment truncated cone (1) into the spring collet assembly (2), and make the end face of the tool (100) to be tested in solid contact with the end face of the measuring rod (41), and tighten the locking nut (5); insert the tool holder of the tool (100) to be tested into the machine tool fixture (300), so that the end face of the alignment truncated cone (1) is pressed against and aligned with the end face (301) of the machine tool fixture, and lock the machine tool fixture (300); then remove the rotary tool axial positioning device (400), which will ensure that the extension length of the tool (100) to be tested is equal to the specified value.

2. The rotary cutting tool axial positioning device according to claim 1, characterized in that: The material of the aligning truncated cone (1) is bearing steel GCr15, with a heat treatment hardness of HRC61~66, and the diameter of the central hole is clearance-fitted with the diameter of the test tool (100).

3. The axial positioning device for a rotary cutting tool according to claim 1, characterized in that: The chuck handle (7) is made of bearing steel GCr15 and heat-treated to a hardness of HRC61-66. The conical surface of the central conical hole is equal to the conical angle of the outer conical surface of the ER spring chuck (6).

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