Modular interface structure of universal quick-change cutter handle

Abstract

The invention relates to the technical field of BT knife handles, in particular to a modular interface structure of a universal quick-change knife handle, which comprises a knife handle, a blind rivet and a thermal shrinkage rod, the knife handle is composed of a circular truncated cone section and a circular ring section, the interior of the knife handle is of a hollow structure, a first threaded hole is formed in the left end of the circular truncated cone section, and a second threaded hole is formed in the right end of the circular ring section; the blind rivet is in threaded connection with the cutter handle through the first threaded hole, and the thermal shrinkage rod is in threaded connection with the cutter handle through the second threaded hole. The blind rivet and the thermal shrinkage rod are designed into detachable and replaceable independent modules and are in standardized threaded connection with the knife handle, and accumulated errors which are difficult to control in multi-stage assembly are structurally eliminated; the thermal shrinkage rod is used as an independent standardized function module, and the universal threaded connector at the tail end of the thermal shrinkage rod can adapt to various knife handles with different standards and specifications.

Description

A modular interface structure for a universal quick-change tool holder Technical Field

[0001] This invention relates to the field of BT toolholder technology, specifically to a modular interface structure for a universal quick-change toolholder. Background Technology

[0002] In the field of machining, especially in the application of numerical control machining centers (CNC), the tool holder is a key functional component that connects the machine tool spindle and the cutting tool. Its performance is directly related to the machining accuracy, efficiency and life of the machine tool spindle.

[0003] Traditional toolholder systems typically employ a multi-component assembly structure. Accumulated fit errors exist at the interfaces between the pull stud, toolholder body, and heat shrink bar. Under high-speed, high-load cutting conditions, this easily leads to fretting, resulting in decreased overall rigidity and repeatability, affecting the surface finish. Furthermore, with the diversification of machining tasks, frequent changes of different types (e.g., milling cutters, drills, boring tools) and different shank diameters are required. In traditional solutions, the heat shrink bar is often tied to a specific toolholder model, making it difficult to use interchangeably with toolholders from different spindle interfaces such as BT30, BT40, BT50, and even HSK. Users need to equip each toolholder with a dedicated heat shrink bar assembly, increasing equipment investment costs and the complexity of tool changer management. Traditional toolholders often undergo surface coating for rust prevention. However, after long-term use, the coating is easily worn or peeled off due to friction and impact, not only losing its rust-prevention function but also potentially contaminating the machine tool and workpiece with wear debris. Moreover, the accuracy of the toolholder's tapered surface is permanently lost after coating wear, requiring complete replacement, which is uneconomical. Therefore, we propose a modular interface structure for a universal quick-change toolholder to solve these problems. Summary of the Invention

[0004] The purpose of this invention is to provide a modular interface structure for a universal quick-change toolholder, in order to solve the problems mentioned in the background art. Traditional toolholder systems typically adopt a multi-component assembly structure, which is prone to micro-motion under high-speed, high-load cutting conditions, and require frequent replacement of different types and diameters of tools, increasing equipment investment costs and the management complexity of the tool changer. Furthermore, the accuracy of the toolholder tapered surface will be permanently lost after the coating of the traditional toolholder is worn.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a modular interface structure for a universal quick-change tool holder, comprising a tool holder, a pull pin, and a heat shrink rod. The tool holder is composed of a frustum section and an annular section. The interior of the tool holder is a hollow structure. A threaded hole is provided at the left end of the frustum section, and a threaded hole is provided at the right end of the annular section. The pull pin is threadedly connected to the tool holder through the threaded hole, and the heat shrink rod is threadedly connected to the tool holder through the threaded hole.

[0006] Preferably, the outer surface of the annular segment is symmetrically provided with driving keyways, the opening of the driving keyways facing one side of the frustum segment, and a positioning hole and a positioning end face are also provided on the right side of the annular segment, the positioning hole being located outside the threaded hole two.

[0007] Preferably, the outer surface of the annular segment is symmetrically provided with driving keyways, the opening of the driving keyways facing one side of the frustum segment, and a positioning hole and a positioning end face are also provided on the right side of the annular segment, the positioning hole being located outside the threaded hole two.

[0008] Preferably, the tool holder is made of 3CR13 or 4CR13 material.

[0009] Preferably, the rivet is integrally formed.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By designing the pull stud and heat shrink bar as detachable and replaceable independent modules and connecting them with the tool holder using standardized threaded connections, the present invention eliminates the accumulated errors that are difficult to control in multi-stage assembly from a structural perspective. Combined with the tightening action of the machine tool pull claw on the pull stud, it can ensure that the outer conical surface of the tool holder and the conical hole of the spindle achieve a high-precision, gapless, and tight fit. Combined with the symmetrically arranged drive keyways on the annular section and their engagement with the spindle, it achieves direct and reliable torque transmission, effectively overcoming the micro-motion and vibration problems that may occur in traditional tool holders under high-speed heavy-load cutting, thereby significantly improving the rigidity and dynamic stability of the entire tool holder system and providing a basic guarantee for high-precision and high-quality machining.

[0011] 2. This invention uses a heat shrinkable rod as an independent standardized functional module. Through its universal threaded interface at the tail end, it can be adapted to various tool holders of different standards and specifications, such as BT30, BT40, BT50, HSK63, and HSK100. At the same time, the tool mounting hole at its front end can be compatible with clamping various tool holders, tool heads, milling cutters, drills, etc. This "one-to-many" modular design can quickly adapt to different machine tool spindles and machining tasks, greatly enhancing the machining flexibility of the system, reducing the types and quantities of spare tool holders and accessories in stock, and lowering the overall purchase and use costs for users.

[0012] 3. The tool holder of this invention is made of 3CR13 or 4CR13 stainless steel and is heat-treated to achieve a hardness of about 50HRC, giving the tool holder excellent rust resistance and avoiding loss of accuracy and potential damage to the machine tool spindle caused by rust. At the same time, since no coating is required, the problem of permanent decrease in accuracy caused by coating wear and peeling due to long-term use of traditional tool holders is eliminated, ensuring long-term stability of the tool holder's dimensions and performance throughout its entire life cycle and extending its service life. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 is a front view of the structure of the present invention; Figure 2 is a disassembled view of the structure of the present invention; Figure 3 is a cross-sectional view of the tool holder and heat shrink rod in Figure 1 of the present invention.

[0015] In the figure: 1. Tool holder; 11. Frustum section; 12. Circular section; 121. Drive keyway; 122. Positioning hole; 123. Positioning end face; 2. Pull stud; 3. Heat shrink bar; 31. Threaded post; 311. Positioning post; 32. Frustum post; 321. Tool mounting hole. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please refer to Figures 1-3. One embodiment of the present invention provides a modular interface structure for a universal quick-change tool holder, including a tool holder 1, a pull pin 2, and a heat-shrink rod 3. The tool holder 1 consists of a frustum section 11 and an annular section 12. The interior of the tool holder 1 is hollow. A threaded hole is provided at the left end of the frustum section 11, and a threaded hole is provided at the right end of the annular section 12. The pull pin 2 is threadedly connected to the tool holder 1 through the threaded hole 1, and the heat-shrink rod 3 is threadedly connected to the tool holder 1 through the threaded hole 2. During assembly and use, the pull pin 2 is first screwed onto the threaded hole 1, and then the pull pin is pulled back by the pull claw on the machine tool spindle. 2. This ensures that the outer conical surface of the frustum section 11 is fully fitted with the spindle conical hole, thereby completing the locking and fixing of the tool holder 1. The pull pin 2 is replaceable and applicable to various specifications, optimizing the cumulative error of multi-stage assembly, improving assembly accuracy, and simplifying the structure and reducing costs. The heat shrink rod 3 is fixed to the bottom of the tool holder 1. The lower end of the heat shrink rod 3 can be used with tool holders, cutter heads, milling cutters, drill bits, boring tools, and fly cutters of different materials and models. The heat shrink rod 3 is detachable, allowing it to be used with tool holders of BT30, BT40, BT50, HSK63, HSK100, etc.

[0018] This device, consisting of a frustum section 11 and an annular section 12, solves the problems of traditional toolholder systems, which typically employ multi-component assembly structures, are prone to micro-movements under high-speed, high-load cutting conditions, and require frequent replacement of different types and diameters of tools, increasing equipment investment costs and the complexity of tool changer management; and the problem that the accuracy of the tapered surface of the toolholder will be permanently lost after the coating of the traditional toolholder is worn.

[0019] Furthermore, the outer surface of the annular segment 12 is symmetrically provided with drive keyways 121, the opening of which faces one side of the frustum segment 11. A positioning hole 122 and a positioning end face 123 are also provided on the right side of the annular segment 12, with the positioning hole 122 located outside the threaded hole 2. As shown in Figure 2, this structure allows the drive keyway 121 to engage with the machine tool spindle when the pull claw on the machine tool spindle pulls the pull stud 2 backward, thus achieving a fixed engagement between the tool holder 1 and the machine tool, preventing the tool holder 1 from shaking during high-speed rotation.

[0020] Furthermore, one end of the heat shrink rod 3 is fitted with a threaded post 31 that mates with the threaded hole 2, and the other end of the heat shrink rod 3 is connected to a frustum post 32. The threaded post 31 is connected to a positioning post 311 that mates with the positioning hole 122. A tool mounting hole 321 is provided at the center of the end of the frustum post 32, and a wrench locking surface is provided in the middle of the heat shrink rod 3. This allows for compatibility with hexagonal and cylindrical SK wrenches, making disassembly simpler and easier. Existing disassembly wrenches can be used, such as adjustable wrenches, box wrenches, and punch wrenches. As shown in Figure 3, this structure is used to achieve precise positioning by tightening the threaded post 31 with the threaded hole 2, and by using the positioning hole 122 and the positioning post 311 for precise positioning. Simultaneously, both the left end face of the heat shrink rod 3 and the positioning end face 123 are high-precision end faces. Therefore, after the threaded post 31 and the threaded hole 2 are fully tightened, the left end face of the heat shrink rod 3 can accurately fit against the positioning end face 123, thereby improving the installation accuracy of the heat shrink rod 3.

[0021] Furthermore, the tool holder 1 is made of 3CR13 or 4CR13 material. As shown in Figure 1, this structure is designed to achieve a hardness of 50HRC after heat treatment, giving the tool holder 1 rust-proof properties and preventing rust from affecting tool accuracy or damaging the machine tool spindle. The tool holder 1 is made of high-quality rust-proof steel, and under the condition of meeting machining requirements, no surface treatment is required, and there will be no wear on the surface coating. This avoids the phenomenon of surface coating wear and accuracy loss caused by long-term use of traditional tool holders 1.

[0022] Furthermore, the rivet 2 can be integrally machined with the frustum section 11. As shown in Figures 1 and 2, this structure reduces cumbersome assembly procedures and improves efficiency through integral machining.

[0023] The working principle of this device is as follows: S1: When assembling the tool holder assembly, first screw the pull pin 2 into the threaded hole 1 at the left end of the frustum section 11 of the tool holder 1, and then screw the heat shrink rod 3 into the threaded hole 2 at the right end of the annular section 12 of the tool holder 1 through its threaded post 31, thus completing the assembly of the tool holder 1, pull pin 2 and heat shrink rod 3; the pull pin 2 can be replaced according to the specifications of the machine tool spindle, reducing the cumulative error of multi-stage assembly and improving the overall accuracy.

[0024] S2: Machine tool clamping and positioning: The assembled tool holder 1 is inserted into the machine tool spindle tapered hole. The spindle puller pulls the pull stud 2 backward by the spindle puller, so that the outer tapered surface of the frustum section 11 fits tightly with the spindle tapered hole. At the same time, the drive keyway 121 on the annular section 12 of the tool holder 1 engages with the spindle drive key to achieve circumferential positioning and torque transmission, ensuring that the tool holder 1 is stable and does not wobble when rotating at high speed.

[0025] S3: Tool installation and clamping: A special heating device is used to heat the heat shrink rod 3, which expands the diameter of the tool mounting hole 321 at its lower end, allowing the insertion of the required tool, such as a tool holder or milling cutter; after natural cooling, the heat shrink rod 3 shrinks and clamps the tool, achieving high-precision and high-rigidity clamping; the wrench locking surface in the middle of the heat shrink rod 3 facilitates disassembly and assembly using a general-purpose wrench.

[0026] S4: Overall Workflow After the tool holder 1 is clamped and the tool is installed on the machine tool, the spindle drives the tool holder 1 to rotate. The torque is transmitted through the drive keyway 121, which drives the heat shrink bar 3 and the tool to perform cutting. The tool holder 1 is made of rust-proof steel such as 3CR13 / 4CR13 and is heat-treated to ensure that it will not rust or wear the coating during long-term use and to maintain stable accuracy. The heat shrink bar 3 can be adapted to various tools and tool holder 1 specifications such as BT and HSK series, so as to achieve quick tool change and wide compatibility. The above is the complete working principle of the present invention.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A modular interface structure for a universal quick-change tool holder, characterized in that: The tool includes a handle (1), a pull stud (2), and a heat shrink rod (3). The handle (1) is composed of a frustum section (11) and an annular section (12). The interior of the handle (1) is hollow. The left end of the frustum section (11) has a threaded hole one, and the right end of the annular section (12) has a threaded hole two. The pull stud (2) is threaded to the handle (1) through the threaded hole one, and the heat shrink rod (3) is threaded to the handle (1) through the threaded hole two.

2. The modular interface structure of a universal quick-change tool holder according to claim 1, characterized in that: The outer surface of the annular segment (12) is symmetrically provided with driving keyways (121), the opening of the driving keyway (121) faces one side of the frustum segment (11), and a positioning hole (122) and a positioning end face (123) are also provided on the right side of the annular segment (12), the positioning hole (122) is located outside the threaded hole two.

3. The modular interface structure of a universal quick-change tool holder according to claim 1, characterized in that: One end of the heat shrink rod (3) is fitted with a threaded post (31) that mates with the threaded hole 2. The other end of the heat shrink rod (3) is connected to a frustum column (32). The threaded post (31) is connected to a positioning post (311) that mates with the positioning hole (122). A tool mounting hole (321) is provided at the center of the end of the frustum column (32). A wrench locking surface is provided in the middle of the heat shrink rod (3).

4. The modular interface structure of a universal quick-change tool holder according to claim 1, characterized in that: The tool holder (1) is made of 3CR13 or 4CR13 material.

5. The modular interface structure of a universal quick-change tool holder according to claim 1, characterized in that: The rivet (2) is integrally formed.

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