A tool lock holder for a CNC milling machine

Abstract

This utility model provides a tool holder for CNC milling machines for mounting cutting tools, comprising: a tool holder body, an axial cooling channel, a valve chamber, and a centrifugal adjustment mechanism. The tool holder body includes a first end and a second end disposed opposite to each other. The first end is used to connect to the machine tool spindle, and the second end is used to clamp the cutting tool. The axial cooling channel is used for the flow of cooling medium and is arranged along the axis of the tool holder body. The valve chamber is disposed inside the tool holder body and radially communicates with the axial cooling channel. The centrifugal adjustment mechanism includes a centrifugal block and an elastic element. The centrifugal block is disposed within the valve chamber to generate radial movement, and the elastic element is configured to provide an elastic force to the centrifugal block, causing it to tend to reduce the effective flow area of ​​the axial cooling channel. When the tool holder body rotates, under the action of centrifugal force, the centrifugal block overcomes the elastic force of the elastic element and moves radially outward, increasing the effective flow area of ​​the axial cooling channel at the valve chamber position. The tool holder of this application can improve the utilization efficiency of the cooling medium.

Description

Technical Field

[0001] This application relates to the field of CNC machining, and more specifically, to a tool lock holder for a CNC milling machine. Background Technology

[0002] As a core piece of equipment in modern manufacturing, CNC milling machines achieve high-precision and high-efficiency milling of complex parts through computer numerical control. In this process, the spindle drives the cutting tool to rotate at high speed and cut the workpiece. The tool holder (also known as the tool shank), used to clamp and connect the spindle and the cutting tool, is a key component ensuring machining accuracy and power.

[0003] During milling, intense friction and plastic deformation occur between the cutting tool and the workpiece, generating a large amount of cutting heat. If this heat cannot be dissipated in a timely and effective manner, the cutting edge temperature will rise sharply, leading to rapid tool wear, coating failure, and even chipping, significantly shortening tool life. Simultaneously, excessively high temperatures can also affect the surface quality and dimensional accuracy of the machined workpiece, and cause thermal damage when machining certain heat-sensitive materials.

[0004] To address these issues, the industry widely employs forced cooling with cooling media (such as cutting fluid or oil). The current mainstream solution involves creating an axial cooling channel inside the tool holder, allowing the cooling medium to flow in from the rear end of the spindle, pass through the tool holder, and finally be sprayed onto the cutting area from nozzles at the tool tip or side. This method (commonly known as "internal cooling") effectively delivers coolant to critical areas such as deep cavities and blind holes that are difficult to reach with traditional external flushing. Utility Model Content

[0005] This application provides a tool lock holder for CNC milling machines, which can improve the efficiency of cooling medium utilization.

[0006] Specifically, this application is implemented through the following technical solution: This application provides a tool lock holder for a CNC milling machine, used for mounting tools, including: The tool holder body includes a first end and a second end that are disposed opposite to each other. The first end is used to connect to the machine tool spindle, and the second end is used to clamp the tool. An axial cooling channel is provided for the flow of cooling medium and is arranged along the axis of the tool holder body; The valve chamber is located inside the tool holder body and is radially connected to the axial cooling channel; A centrifugal adjustment mechanism includes a centrifugal block and an elastic element, the centrifugal block being configured to generate radial movement within the valve chamber in response to a rotational speed of the blade holder body, and the elastic element being configured to provide the centrifugal block with an elastic force that tends to reduce the effective flow area of ​​the axial cooling channel; When the tool holder body rotates, the centrifugal block overcomes the elastic force of the elastic element and moves radially outward under the action of centrifugal force, so as to increase the effective flow area of ​​the axial cooling channel at the valve cavity position.

[0007] Optionally, the elastic element is a compression spring.

[0008] Optionally, the centrifugal blocks include at least two and are arranged circumferentially symmetrically around the axial cooling channel.

[0009] Optionally, when the tool holder body is stationary or the rotation speed is below a threshold, the centrifugal adjustment mechanism is in its initial state. At this time, the elastic element pushes the centrifugal block into the axial cooling channel, so that the effective flow cross-sectional area at this position is smaller than the original cross-sectional area of ​​the axial cooling channel.

[0010] Optionally, the centrifuge block includes a first centrifuge block and a second centrifuge block. In the initial state, the inner sides of the first centrifuge block and the second centrifuge block are engaged, and the effective flow cross section forms a closed pattern.

[0011] Optionally, the centrifugal block has an arc-shaped concave surface on one side extending into the axial cooling channel, and the radius of curvature of the arc-shaped concave surface is smaller than the radius of the axial cooling channel.

[0012] Optionally, a radial guide structure is provided between the valve chamber and the centrifuge block to constrain the centrifuge block to move radially along a predetermined path.

[0013] Optionally, the outer periphery of the first end of the tool holder body is provided with a concave annular groove for fixed connection with the output end of the spindle.

[0014] This application provides a tool holder for a CNC milling machine. When the tool holder body is driven to rotate by the spindle, the centrifugal block is subjected to centrifugal force. This centrifugal force is directly proportional to the square of the rotational speed; therefore, the higher the rotational speed, the greater the centrifugal force. The direction of this centrifugal force is opposite to the direction of the elastic force provided by the elastic element. At low speeds or when stationary, the preload of the elastic element causes the centrifugal block to extend into the axial cooling channel, partially blocking the flow channel and reducing the effective flow area. As the rotational speed increases, the centrifugal force begins to overcome the elastic force, driving the centrifugal block radially outward, thereby gradually increasing the effective flow area of ​​the axial cooling channel at the valve cavity position. When the spindle rotates at high speed, the cutting load of the tool increases, and the heat generation intensifies, the flow rate of the cooling medium can automatically increase accordingly, thus providing more sufficient cooling; conversely, at low speeds, during idling, or during tool changes, the flow rate automatically decreases, effectively avoiding waste of the cooling medium. This structure is applicable whether using cooling oil or water-based coolant, achieving a unity of energy saving, environmental protection, and intelligent cooling. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the internal structure of the locking blade holder shown in an exemplary embodiment of this application; Figure 2 This is a partial enlargement of the locking seat shown in an exemplary embodiment of this application. Figure 1 ; Figure 3 This is a partial enlargement of the locking seat shown in an exemplary embodiment of this application. Figure 2 ; Figure 4 This is a cross-section of the locking seat at the valve cavity shown in an exemplary embodiment of this application. Figure 1 ; Figure 5 This is a cross-section of the locking seat at the valve cavity shown in an exemplary embodiment of this application. Figure 2 .

[0016] Wherein: 100, tool holder body; 110, first end; 120, second end; 200, axial cooling channel; 300, valve chamber; 400, centrifugal adjustment mechanism; 410, centrifugal block; 411, first centrifugal block; 412, second centrifugal block; 420, elastic block; 500, guide structure; 600, annular groove. Detailed Implementation

[0017] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0018] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0019] refer to Figure 1 , Figure 2 and Figure 4This application provides a tool holder for a CNC milling machine, used for mounting tools, comprising: a tool holder body 100, an axial cooling channel 200, a valve chamber 300, and a centrifugal adjustment mechanism 400. The tool holder body 100 includes a first end 110 and a second end 120 disposed opposite to each other. The first end 110 is used to connect to the machine tool spindle, and the second end 120 is used to clamp the tool. The axial cooling channel 200 is used for the flow of cooling medium and is disposed along the axis of the tool holder body 100. The valve chamber 300 is disposed inside the tool holder body 100 and radially communicates with the axial cooling channel 200. The centrifugal adjustment mechanism 400 includes a centrifugal block 410 and an elastic element. The centrifugal block 410 is configured to move radially within the valve chamber 300 in response to the rotational speed of the tool holder body 100. The elastic element is configured to provide an elastic force to the centrifugal block 410, causing it to tend to reduce the effective flow area of ​​the axial cooling channel 200. When the tool holder body 100 rotates, under the action of centrifugal force, the centrifugal block 410 overcomes the elastic force of the elastic element and moves radially outward to increase the effective flow area of ​​the axial cooling channel 200 at the valve cavity 300 position.

[0020] When the tool holder body 100 is driven to rotate by the spindle, the centrifugal block 410 is subjected to centrifugal force. This centrifugal force is directly proportional to the square of the rotational speed; therefore, the higher the rotational speed, the greater the centrifugal force. The direction of this centrifugal force is opposite to the direction of the elastic force provided by the elastic element.

[0021] At low speeds or when stationary, the preload of the elastic element causes the centrifugal block 410 to extend into the axial cooling channel 200, partially blocking the flow channel and reducing the effective flow area. As the rotational speed increases, the centrifugal force begins to overcome the elastic force, driving the centrifugal block 410 to move radially outward, thereby gradually increasing the effective flow area of ​​the axial cooling channel 200 at the valve cavity 300.

[0022] This mechanical feedback mechanism automatically matches the cooling medium flow rate with the spindle speed. The resulting technical benefits are: when the spindle rotates at high speed, the cutting load on the tool increases, and heat generation intensifies, the cooling medium flow rate automatically increases, providing more adequate cooling; conversely, during low-speed operation, idling, or tool changes, the flow rate automatically decreases, effectively preventing waste of cooling medium. This structure is applicable to both oil-based and water-based coolants, achieving a balance between energy saving, environmental protection, and intelligent cooling.

[0023] refer to Figure 4 and Figure 5In one embodiment, the elastic element is a compression spring. A compression spring is chosen as the elastic element. To achieve a stable and reliable response, the compression spring should have high stiffness, meaning that its deformation during the working stroke is small, providing a relatively stable elastic force. Simultaneously, the compression spring itself should have a compact structure and uniform mass distribution to reduce vibration or offset tendencies caused by its own mass imbalance under high-speed rotation, ensuring the accuracy and stability of the centrifugal block 410's movement.

[0024] refer to Figure 3 and Figure 5 The centrifugal blocks 410 comprise at least two and are arranged circumferentially symmetrically around the axial cooling channel 200. This symmetrical design firstly ensures the dynamic balance of the rotating components at high speeds, avoiding severe vibrations caused by mass asymmetry. Secondly, from a fluid dynamics perspective, the multiple centrifugal blocks 410 synchronously and uniformly adjust the flow channel area from all sides, effectively preventing flow field skewing or eddies, resulting in a smoother and more uniform increase in effective flow area, which is beneficial for the stable flow of the cooling medium.

[0025] refer to Figure 2 and Figure 4 In one embodiment, when the tool holder body 100 is stationary or its rotational speed is below a threshold, the centrifugal adjustment mechanism 400 is in its initial state. At this time, the elastic element pushes the centrifugal block 410 into the axial cooling channel 200, making the effective flow cross-sectional area at this position smaller than the original cross-sectional area of ​​the axial cooling channel 200. When the tool holder body 100 is stationary or its rotational speed is below a certain threshold, the mechanism is in its initial state. At this time, the centrifugal block 410 extends into the channel under the action of the elastic element, making the flow area smaller than the original area. This initial state setting structurally reserves adjustment space for the flow rate to increase as the rotational speed increases. It ensures that the mechanism has the ability to adjust from "throttling" to "smooth flow".

[0026] In one embodiment, the centrifugal block 410 includes a first centrifugal block 411 and a second centrifugal block 412. In the initial state, the inner sides of the first centrifugal block 411 and the second centrifugal block 412 are engaged, and the effective flow cross-section forms a closed shape. In the initial state, the inner sides of the centrifugal blocks 410 are close together and engaged, so that the effective flow cross-section at that location forms a closed shape, such as a circle or a square. This closed structure can maximize the obstruction of the cooling medium flow path in the low-speed stage, thereby optimizing the throttling effect and further strengthening the initial goal of energy saving.

[0027] refer to Figure 5In one embodiment, the centrifugal block 410 has an arc-shaped concave surface on one side extending into the axial cooling channel 200, the radius of curvature of which is smaller than the radius of the axial cooling channel 200. When two such centrifugal blocks 410 are engaged in the initial state, their arc-shaped concave surfaces can together form an approximately circular throttling orifice. A circular flow cross-section has advantages in fluid dynamics, with a low flow resistance coefficient, allowing the cooling medium to flow relatively smoothly even under throttling conditions. refer to Figure 4 and Figure 5 In one embodiment, a radial guide structure 500 is provided between the valve chamber 300 and the centrifugal block 410 to constrain the centrifugal block 410 to move radially along a predetermined path. First, the guide structure 500 provides guidance and constraint for the radial movement of the centrifugal block 410, ensuring it moves along the predetermined path. This reduces the lateral bending moment and compression of the elastic element (such as a compression spring) generated by the centrifugal block 410 during movement, effectively preventing large-scale displacement and bending of the elastic element due to non-axial forces, and improving the reliability of the entire mechanism. Second, by setting the stroke length of the guide structure 500, the extreme position of the outward movement of the centrifugal block 410 can be mechanically limited, thereby controlling the maximum effective flow area that the axial cooling channel 200 can open, achieving rigid protection of the flow rate limit.

[0028] One specific implementation of the guide structure 500 is to set a radially extending limiting guide rail inside the valve cavity 300, and simultaneously set a limiting slider at the corresponding position of the centrifugal block 410. The movement guidance is achieved through the cooperation between the slider and the guide rail. Another implementation is the cooperation between a guide rod and a guide sleeve. That is, the guide rod is fixed to the valve cavity 300, and a guide sleeve that fits on the centrifugal block 410 is set therewith. The centrifugal block 410 slides along the guide rod through the guide sleeve, which can also achieve the effect of precise guidance and limiting.

[0029] refer to Figure 1 In one embodiment, a concave annular groove 600 is provided on the outer periphery of the first end 110 of the tool holder body 100 for connection with the output end of the spindle. When the locking mechanism of the spindle is engaged in this annular groove 600, the two form a hook relationship, thereby effectively preventing the tool holder from moving or disengaging along the axial direction within the spindle hole, ensuring the axial stability of the connection. The annular groove 600 is also provided with a circumferentially engaging keyway, which engages with the locking mechanism to provide anti-torsion capability. It can reliably transmit the huge torque generated when the spindle drives the tool to cut, preventing relative rotation between the tool holder and the spindle, thus achieving circumferential fixation.

[0030] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A tool locking holder for a CNC milling machine, characterized in that, For mounting cutting tools, including: The tool holder body (100) includes a first end (110) and a second end (120) disposed opposite to each other. The first end (110) is used to connect with the machine tool spindle, and the second end (120) is used to clamp the tool. An axial cooling channel (200) is provided for the flow of cooling medium and is arranged along the axis of the tool holder body (100); The valve chamber (300) is located inside the tool holder body (100) and is radially connected to the axial cooling channel (200); The centrifugal adjustment mechanism (400) includes a centrifugal block (410) and an elastic element, the centrifugal block (410) being configured to generate radial movement within the valve chamber (300) in response to a rotational speed of the blade holder body (100), and the elastic element being configured to provide the centrifugal block (410) with an elastic force that tends to reduce the effective flow area of ​​the axial cooling channel (200); When the blade holder body (100) rotates, the centrifugal block (410) overcomes the elastic force of the elastic element and moves radially outward under the action of centrifugal force, so as to increase the effective flow area of ​​the axial cooling channel (200) at the valve cavity (300).

2. The tool locking holder for a CNC milling machine as described in claim 1, characterized in that, The elastic element is a compression spring.

3. The tool locking holder for a CNC milling machine as described in claim 1, characterized in that, The centrifugal blocks (410) include at least two and are arranged circumferentially symmetrically around the axial cooling channel (200).

4. The tool locking holder for a CNC milling machine as described in claim 3, characterized in that, When the tool holder body (100) is stationary or the rotation speed is below the threshold, the centrifugal adjustment mechanism (400) is in the initial state. At this time, the elastic element pushes the centrifugal block (410) into the axial cooling channel (200), so that the effective flow cross-sectional area at this position is smaller than the original cross-sectional area of ​​the axial cooling channel (200).

5. The tool locking holder for a CNC milling machine as described in claim 4, characterized in that, The centrifuge block (410) includes a first centrifuge block (411) and a second centrifuge block (412). In the initial state, the inner sides of the first centrifuge block (411) and the second centrifuge block (412) are engaged, and the effective flow section forms a closed pattern.

6. The tool locking holder for a CNC milling machine as described in claim 5, characterized in that, The centrifugal block (410) has an arc-shaped concave surface on one side of the axial cooling channel (200), and the radius of curvature of the arc-shaped concave surface is smaller than the radius of the axial cooling channel (200).

7. The tool locking holder for a CNC milling machine as described in claim 1, characterized in that, A radial guide structure (500) is provided between the valve chamber (300) and the centrifugal block (410) to constrain the centrifugal block (410) to move radially along a predetermined path.

8. The tool locking holder for a CNC milling machine as described in claim 1, characterized in that, The outer periphery of the first end (110) of the tool holder body (100) is provided with a concave annular groove (600) for fixed connection with the output end of the spindle.

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