TWM673810U - Tool locking and tool length positioning structure - Google Patents

Abstract

This invention provides a locking and length-positioning structure for cutting tools. It includes a shank with an inwardly extending cutter hole formed on its end face for receiving a cutter handle sleeve. The shank also has at least one internal threaded hole on one side for receiving a locking screw. The locking screw has a spherical tip. The shank also has at least one positioning hole in the shape of an internal spherical hole formed on one side of the cutter handle. The positioning hole aligns with the spherical tip of the locking screw for locking.

This invention distributes force along the X, Y, and Z axes by pressing the sphere against the inner surface of the positioning hole. Combined with the tool-holding hole's constraints, the tool holder is completely restrained along the X, Y, and Z axes. This not only allows for precise tool positioning, but also effectively limits the tool's freedom along the three axes and locks it in place.

Description

Tool locking and blade length positioning structure

This invention relates to an improved structure for positioning and locking the blade length of a knife, providing precise and rapid positioning and locking functions.

As shown in Figures 12 and 13, the known cutting tools, especially the cutting tools such as the drill bit 5 or the milling cutter 6, have cylindrical shanks 51 and 61. For locking the cylindrical shanks 51 and 61, some tool rods 4 are tightened by using a set screw 41, while some tool rods 7 are tightened by using an elastic collet chuck 71 in conjunction with a nut 72. For example, Patent Document No. I530346, a tool rod assembly for a milling machine with a tool holder that can be quickly replaced, is disclosed. The tool (30A) shown in Figures 3 and 4 is pressed against the side of the tool (30) by the clamping member (223), so that the tool (30) is fixed to the tool clamp (20A). Please refer to Figures 5 and 6 of the patent document. The tool (30B) is correspondingly inserted into the collet (23) and is tightened by the clamping ring (24) screw, so that the tool (30B) can be fixed in the tool clamp (20B).

As shown in Figures 12 and 13, the conventional locking method of cutting tools cannot accurately position the length of the tool. When the drill bit 5 or the milling cutter 6 is placed in the tool bar 4 or 7, it is fixed by the stop screw 41 or the elastic clamp 71 with the nut 72. As shown in Figures 14 and 15, the drill bit 5 has a gap C that allows it to move up and down due to the width W of the locking surface 52, and the tool length cannot be accurately positioned. Similarly, as shown in Figure 16, the milling cutter 6 clamped by the elastic collet 71 also has a gap C that allows it to move up and down. The gap C between the moving parts prevents accurate tool length positioning. Therefore, the tool length must be calibrated using a tool setter before installation on the processing machine. Alternatively, after the tool is installed on the processing machine, a Z-axis setter must be used to set the reference tool length for both the machine and the tool to ensure accurate machining dimensions. Therefore, tool length resetting is required with each tool change. This time-consuming tool length calibration increases wasted processing time and costs for the operator. Furthermore, employee training in tool length calibration is essential.

It's known that the tool's locking mechanism cannot directly determine the tool's length. Tool length calibration equipment is required to calibrate the tool. Therefore, each tool change requires resetting the tool length. This significantly increases costs for the processing industry.

This invention provides a locking and length-positioning structure for cutting tools. It includes a shank with an inwardly extending cutter hole formed on its end face for receiving a cutter handle sleeve. The shank also has at least one internal threaded hole on one side for receiving a locking screw. The locking screw has a spherical tip. The shank also has at least one positioning hole in the shape of an internal spherical hole formed on one side of the cutter handle. The positioning hole aligns with the spherical tip of the locking screw for locking.

The positioning hole in the toolholder of this invention is gradually tightened by the thrust of the sphere at the tip of the locking screw, adjusting the tool's height on the Z axis and allowing for slight rotational adjustment to the correct position, allowing the tool's length to be precisely positioned. Simultaneously, the sphere presses against the inner surface of the positioning hole, distributing the force along the X, Y, and Z axes. Combined with the constraints of the tool-holding hole, the toolholder is completely constrained along the X, Y, and Z axes, effectively securing the tool's length and limiting its freedom along the three axes while locking it in place.

10, 4, 7: Knife handle

11: Knife hole

110: Tapered hole

111, 71: Elastic Collet

112, 72: Nut

113: Perforation

12: Internal screw hole

2: Locking screws

21: Sphere

210: Cone

211: Accommodation hole

22: Steel Balls

3: Cutting tools

31, 51, 61: Handle

32, 320: Positioning holes

41: Set screw

5: Drill bit

52: Locking plane

6: Milling cutter

8: Positioning detection rod

L: Groove depth

W: Width

C: Gap

Figure 1 is a three-dimensional system diagram of this creation.

Figure 2 is a cross-sectional view of this work.

Figure 3 is a schematic diagram of the X-Z plane of the locking screw and the tool handle in this invention.

Figure 4 is a schematic diagram of the X-Y plane of the spherical locking screw and the positioning hole of the tool handle in this creation.

Figure 5 shows an example of the invention being implemented on an elastic collet.

Figure 6 is a schematic diagram of different positioning hole depth locking in this creation.

Figure 7 is a schematic diagram of the two sets of locking screws and the positioning holes of the tool handle in this creation.

Figures 8 and 9 are schematic diagrams of repeated positioning detection using this invention's positioning detection rod.

Figure 10 is an example of an embodiment of the invention in which the end face of the locking screw is conical in shape.

Figure 11 is an example of an embodiment of the invention in which a steel ball is embedded in the end face of the locking screw.

Figure 12 is a diagram showing the assembly of a BT shank locking tool.

Figure 13 shows a schematic diagram of the ER toolholder and the collet clamp used to lock the tool.

Figure 14 is a diagram showing the limit position of the tool face before using a set screw to lock the tool face.

Figure 15 is a diagram showing the limit position of the end face locking below the tool plane before using a set screw.

Figure 16 is a diagram of a tool being locked with a collet.

Referring to Figures 1 and 2, this invention includes a tool bar 10. An inwardly extending tool receiving hole 11 is formed on the end face of the tool bar 10. At least one internal threaded hole 12 is formed on one side of the tool bar 10. The internal threaded hole 12 receives a locking screw 2. The internal threaded hole 12 extends through the tool receiving hole 11. The tool receiving hole 11 receives a tool handle 31 of a tool 3, wherein:

The locking screw 2 has a spherical body 21 at its front end;

The tool 3 is provided with at least one positioning hole 32 in the shape of an inner spherical hole on one side of the tool handle 31. The inner spherical radius of the positioning hole 32 is the same as that of the spherical body 21 of the locking screw 2.

As shown in FIG2 , the present invention provides at least one positioning hole 32 in the shape of an inner ball hole on one side of the handle 31 of the tool 3. When the tool 3 is inserted into the tool receiving hole 11 of the tool bar 10, the spherical body 21 provided at the front end of the locking screw 2 is pushed into the positioning hole 32. The length of the tool 3 can be quickly positioned. As the locking screw 2 is gradually tightened, the spherical body 21 at the front end gradually pushes the positioning hole 32. As shown in FIG2 , 3 and 4 , the positioning hole 32 is gradually sealed with the spherical body 21 by the thrust of the spherical body 21. The tool 3 is then contacted, and its height on the Z axis is adjusted and slightly rotated to the correct position, allowing the tool 3 to be precisely positioned. Simultaneously, the sphere 21 presses against the positioning hole 32. The thrust of the sphere 21 is distributed on the inner surface of the positioning hole 32, and this force, combined with the restriction of the tool holder 11, completely constrains the tool holder 31 on the X, Y, and Z axes. This not only allows the tool 3 to be precisely positioned, but also effectively limits the freedom of the tool 3 on the three axes and locks it in place.

Please refer to FIG5, which is an embodiment of the invention applied to an elastic collet. The end face of the tool bar 10 of the invention is provided with a tool hole 11 extending inward and a tapered hole 110. An elastic collet 111 is accommodated in the tapered hole 110. The handle 31 of a tool 3 is accommodated in the tapered hole 110 and the elastic collet 111 and is locked by a nut 112. The elastic collet 1 A through-hole 113 is provided at the position corresponding to the internal threaded hole 12 of the tool bar 10. The locking screw 2 is threaded into the internal threaded hole 12. The spherical body 21 at the front end of the locking screw 2 is positioned and locked with the positioning hole 32 of the tool handle 31. Combined with the elastic collet 111, this provides dual restraint and locking effects, especially when used in heavy cutting applications, and can better withstand higher cutting torque and cutting stress.

See Figure 6 for torque testing of the positioning hole 32 of this invention with different groove depths L and the sphere 21 locked. In this test, the toolholder 31 has a diameter of 6mm, the sphere 21 has a diameter of 4mm, and the groove depth L is 0.5mm. The tool can withstand a torque of 12Nm (Newton-meter), with a breaking torque of 14Nm. The tool with a groove depth L of 0.7mm can withstand a torque of 14Nm (Newton-meter), with a breaking torque of 16N. m, with a groove depth L of 0.9mm, it can withstand a torque of 18Nm (Newton-meter) and a breaking torque of 20Nm. A 6mm diameter steel rod made of the same material, clamped in an ER16 elastic collet, can only withstand a torque below 9Nm. Above 10Nm, the 6mm steel rod begins to slip. In this experimental comparison, our invention, using the corresponding locking mechanism of the sphere 21 and the positioning hole 32, exhibits considerable locking strength.

Please refer to Figure 7, which shows an embodiment of this invention with two sets of spheres 21 and positioning holes 32. A single set of spheres 21 (4mm ball diameter) and positioning holes 32 (6mm shank diameter) with a groove depth L of 0.9mm can withstand a torque of 18Nm (as shown in Figure 6). However, a typical 6mm drill bit only requires 3-4Nm of torque when machining medium-carbon steel. To clamp larger drill bits or milling cutters, and to withstand greater torque, the number of spheres 21 and positioning holes 32 can be increased. Figure 7 shows an embodiment with two sets of spheres 21 and positioning holes 32, which can handle larger drilling or milling operations with higher cutting stresses.

Please refer to Figures 8 and 9, which show the milling and positioning test of this invention's positioning rod 8. One end of a 25mm diameter round bar is turned into a 6mm round bar tool holder 31, which is provided with a positioning hole 32 for a 4mm diameter concave sphere. A flat notch is milled on the other end of the positioning rod 8. The positioning rod 8 is then attached to the tool holder 10 and secured with a locking screw 2. Four-point positioning is then performed on a measuring instrument (as indicated by the four black dots on the flat notch in the figure). Precision repeatability measurements of the X, Y, and Z axes are performed, and the measured values are all within 0.01mm. Therefore, the repeatability accuracy of the sphere 21 and the positioning hole 32 in this invention is within 0.01mm, demonstrating its high repeatability.

Please refer to Figure 10, which shows an embodiment of this invention using a cone instead of a sphere. The locking screw 2 has a conical tip 210. The tool 3 has at least one conical positioning hole 320 on one side of the tool handle 31. The overlapping cones achieve precise positioning and locking, providing the same high locking strength and precise positioning as the previously described spherical sphere 21 and positioning hole 32.

Please refer to Figure 11, which shows an embodiment of a locking screw 2. The locking screw 2 has a receiving hole 211 at its front end. The receiving hole 211 is designed to receive a steel ball 22. Accordingly, the spherical body 21 at the front end of the locking screw 2 is designed as an embedded structure. This allows the spherical body 21 at the front end of the locking screw 2 to be formed into an integral spherical shape by turning (as shown in Figures 1-4), or it can be formed by embedding a steel ball 22.

This invention utilizes a spherical design at the tip of the locking screw, coupled with a spherical inner hole for the locking locating hole. The spherical thrust gradually closes the locating hole, adjusting the tool's height on the Z axis and rotating it to the correct position, enabling precise and rapid tool positioning. Simultaneously, as the spherical thrust presses against the locating hole, the spherical thrust is distributed along the X, Y, and Z axes on the inner surface of the locating hole. Combined with the constraints of the tool-holding hole, this fully constrains the toolholder along the X, Y, and Z axes, effectively limiting the tool's freedom along these three axes and locking it in place. This is a highly progressive and innovative design.

In summary, this work has the following progressive and innovative advantages:

1. Save time on setting the blade length.

2. Excellent tool locking strength improves tool rigidity and can effectively increase tool cutting feed, improving cutting efficiency and reducing cutting costs.

3. Increased tool positioning and locking force effectively prevents slipping and rotation at the tool locking point, avoids the danger of blade impact, and prevents tool damage, thereby improving processing safety.

4. Tool positioning is precise and fast.

This design can effectively address the shortcomings of existing technology, enabling quick and precise tool length positioning. The improved locking structure prevents tool slippage, blade impact, and tool damage, effectively enhancing machining safety.

10: Knife handle

11: Knife hole

12: Internal screw hole

2: Locking screws

21: Sphere

3: Cutting tools

31: Handle

32: Positioning hole

Claims (4)

A tool locking and length positioning structure includes a tool bar, wherein the tool bar has an inwardly extending tool receiving hole formed on its end surface. The tool bar has at least one internal threaded hole formed on one side thereof, the internal threaded hole being adapted to receive a locking screw. The internal threaded hole extends through the tool receiving hole, and the tool receiving hole is adapted to receive a tool handle sleeve. The locking screw has a spherical shape at its front end; The aforementioned cutting tool has at least one positioning hole in the shape of an inner spherical hole on one side of the tool handle. The locking and blade length positioning structure of the cutting tool as described in claim 1, wherein the front end of the locking screw is configured as a cone, and the cutting tool has at least one conical positioning hole provided on one side of the shank. In the locking and blade length positioning structure for a cutting tool as described in claim 1, the front end of the locking screw is provided with a receiving hole for inserting a steel ball. The tool locking and blade length positioning structure described in claim 1 includes at least two internal screw holes on one side of the tool shank, which are used to lock the tool with two locking screws, and at least two positioning holes in the shape of internal spherical holes on one side of the tool handle.