Chuck device of numerical control machine tool and clamping method of chuck device
By integrating adjustable and locking slide bars on the jaws, the problem of three-jaw chucks being unable to clamp irregular workpieces is solved, achieving a combination of precise positioning and automatic centering, thus improving machining accuracy and ease of operation.
Patent Information
- Application Number
- CN202511513430.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-22
- Publication Date
- 2026-01-02
AI Technical Summary
Existing three-jaw chucks are difficult to effectively clamp irregular workpieces with planar outer walls, resulting in low machining accuracy, cumbersome operation, and safety hazards.
The chuck integrates an independently adjustable and lockable slide bar, which achieves precise positioning of the workpiece's flat or irregular outer surface through guide grooves and locking components. Combined with the automatic centering function, the adjustment and locking mechanism is built into the chuck.
It achieves a combination of precise positioning and automatic centering for irregular workpieces, simplifies the operation process, improves processing accuracy and safety, and reduces maintenance costs.
Smart Images
Figure CN121245033A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of CNC machine tool technology, and in particular to a chuck device for a CNC machine tool and its clamping method. Background Technology
[0002] In the field of modern machining, CNC machine tools have become the core equipment for achieving high-precision and high-efficiency manufacturing. Among them, the chuck, as a key functional component on a CNC machine tool used for clamping workpieces, directly affects the machining accuracy and clamping efficiency. Three-jaw chucks, due to their automatic centering and stable clamping characteristics, are widely used for clamping regular rotating workpieces such as cylinders, regular triangles, or regular hexagons. However, with increasingly complex component designs, workpieces with irregular shapes, such as cylinders with one or more planar outer walls (e.g., wrench heads, hydraulic valve blocks), are increasingly used in machining. These workpieces pose a serious challenge to the existing clamping methods of three-jaw chucks. For example, when the workpiece's outer wall has a plane, especially when the central angle corresponding to that plane is large (e.g., exceeding 120°), the jaws of a traditional three-jaw chuck only have point or line contact with the workpiece. The small contact area and concentrated clamping force make it extremely easy for the workpiece to loosen or shift during machining, seriously affecting machining accuracy and even causing safety accidents.
[0003] Existing three-jaw chucks are designed for regular rotating bodies and lack a dedicated positioning mechanism for mating with the outer wall of the workpiece. To address this issue, those skilled in the art typically use temporary shims added to the bottom of the jaws or adjusting screws screwed in. This method is extremely inefficient, requiring repeated screw tightening and numerous measurements, making it cumbersome and time-consuming, unsuitable for mass production. Secondly, it's difficult to guarantee the parallelism of the positioning surfaces; the screw tip often makes point contact with the workpiece surface, which can easily cause the workpiece to tilt under clamping force, making positioning accuracy entirely dependent on the operator's experience. Furthermore, existing adjustment mechanisms are prone to accidental displacement during operation. Even with adjusting screws, during the initial adjustment and the lull before locking, the screw or similar adjusting components are highly susceptible to accidental slippage due to their own weight or slight impact, causing the preset positioning position to fail and requiring readjustment. This further increases operational uncertainty and time costs. Summary of the Invention
[0004] The purpose of this invention is to provide a chuck device for CNC machine tools and its clamping method, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention provides a chuck device for a CNC machine tool, comprising a chuck body and jaws. The jaws are arranged in a circumferential array along the axis of the chuck body, and the jaws are movably connected to move synchronously towards or away from the axis of the chuck body. The jaws include: The guide grooves are arranged in two sets symmetrically along the width direction, and the extension direction of the guide grooves is parallel to the movement direction of the corresponding claw. The adjustment assembly has two slide rods and at least one screw rod, the slide rods being slidably disposed in the guide groove, and the screw rod being rotatably disposed in the pawl and perpendicular to the slide rods; A locking assembly includes an end plate, a baffle, and a rocker arm. The side of the pawl has a groove. The end plate is disposed within the groove and covered by the baffle. One end of a screw passes through the end plate and the baffle and is detachably connected to the rocker arm. The end plate has a threaded hole that engages with a thread on the screw. This allows the locking assembly to be configured with a first working state and a second working state. The locking assembly drives the end plate to move via the rotation of the screw, causing the end plate to press against the outer wall of the slide rod in the first working state and to separate from the slide rod in the second working state.
[0006] This invention integrates independently adjustable and lockable sliding rods into the jaws, enabling traditional three-jaw chucks to precisely position workpieces on flat or irregular outer surfaces without requiring fixture replacement. The synchronous radial movement function of the jaws themselves remains intact, allowing for automatic centering even on curved surfaces of the workpiece. This preserves the automatic centering function, achieving a combination of positioning and centering. Furthermore, all adjustment and locking mechanisms are built into the jaws, occupying no additional space and maintaining the chuck's overall integrity.
[0007] As a further improvement of the present invention: the groove body has a shallow groove and a deep groove that communicate with the guide groove. The shallow groove is used to accommodate the end plate, and the deep groove is used to allow the end plate to abut against the side of the slide rod. The structure of the shallow groove and the deep groove realizes the accommodation and guidance of the end plate, and ensures that the force of the end plate can be effectively transmitted to the slide rod, resulting in good structural rigidity.
[0008] As a further improvement of the present invention: the end plate has a main body and a contact part. The main body is disposed in the shallow groove, and the contact part is disposed in the deep groove. The contact part is located between the main body and the slide rod and contacts the side of the slide rod. The main body is responsible for transmission, and the contact part is responsible for clamping. The two can be manufactured and replaced separately, reducing manufacturing difficulty and maintenance costs. The connection between the main body and the contact part can be a threaded connection, a pin connection, or a key connection.
[0009] As a further improvement of the present invention: the threaded hole is provided on the main body, the screw is threadedly engaged with the threaded hole on the main body, one end of the screw extends to connect with the rocker arm, and the other end is rotatably supported in the jaws by a bearing structure, so that when the screw is rotated, the end plate moves along the axial direction of the screw. The threaded engagement of the screw with the threaded hole on the main body converts the rotational motion into translational motion and transmits it to the end plate.
[0010] As a further improvement of the present invention, an elastic element is provided between the main body and the contact portion, so that the contact portion constantly presses against the side of the slide rod, providing a preload force. The preload force can eliminate transmission gaps between components, making the locking process faster and smoother.
[0011] As a further improvement of the present invention: the contact portion is provided with a through stepped groove and a friction block disposed in the stepped groove. The stepped groove has a first step of relatively large size and a second step of relatively small size. The first step is located at one end adjacent to the main body, and the second step is located at one end adjacent to the slide rod. The friction block has a guide portion and a friction abutment end. The guide portion is adapted to and movably connected to the inner contour surface of the first step. The friction abutment end passes through the second step and abuts against the side of the slide rod. The elastic element is disposed between the main body and the guide portion. As a consumable part, the friction block only needs to be replaced after wear, rather than the entire end plate. The stepped groove structure disperses the huge pressure during locking onto the main body of the contact portion, avoiding local plastic deformation.
[0012] As a further improvement of the present invention: the friction contact end is provided with a rounded chamfer or bevel in the extension direction of the guide groove, so that when the slide rod is inserted into the guide groove, the contact chamfer or bevel pushes the contact part back into the groove. The rounded chamfer or bevel of the friction contact end allows the slide rod to be smoothly guided in when installing or replacing it, without jamming with the end plate, thus improving the convenience of assembly.
[0013] As a further improvement of the present invention: the baffle is provided with a hollow boss at the end position of the screw, the hollow boss is coaxially arranged with the screw, and the rotating end of the rocker arm is disposed in the hollow boss and movably connected along the axial direction. The rotating end of the rocker arm is detachably sleeved with the end of the screw arm through a spline or non-circular cross section, so that the transmission connection is achieved when the rocker arm is pushed in and the connection is disconnected when it is pulled out. This rocker arm requires little operating space, has a reliable connection, and can be removed when not in use to avoid interference, thus improving operational safety and convenience.
[0014] On the other hand, the present invention also provides a clamping method for a chuck device of a CNC machine tool, which utilizes the chuck device of a CNC machine tool as described above to achieve the following steps: Place the workpiece axially into the center of the chuck body; Based on the shape characteristics of the workpiece's outer surface, determine the position of the slide bar that needs to be adjusted, including: identifying the position of the jaw corresponding to the outer wall of the workpiece plane, and determining the slide bar on the jaw that needs to contact the outer wall of the plane; By controlling the rotation of the corresponding screw with a rocker arm, the locking assembly is switched to the second working state, the lock on the slide bar is released, and the extension length of the slide bar is adjusted so that its end can fully contact the outer wall of the plane. When adjusting the extension length of the slide bar, the preload provided by the elastic element is used to keep the slide bar position stable and prevent the slide bar from moving accidentally during the adjustment process. By controlling the screw to rotate in the opposite direction with the joystick, the locking component is switched to the first working state, locking the slide position; The three jaws are synchronously controlled to retract towards the axis of the chuck body, thus stably clamping the workpiece.
[0015] As a further improvement of the present invention: when the workpiece has multiple irregular outer surfaces, the extension length of the sliding rod on different jaws can be adjusted independently, including: Each slide bar that needs to contact the outer surface of the workpiece is adjusted individually; Temporary positioning is provided by the frictional contact between the friction block and the side of the slide bar; After locking each slide bar one by one, the chuck jaws are then synchronously controlled to retract towards the axis of the chuck body to stably clamp the workpiece.
[0016] This invention provides a temporary positioning adjustment process through the frictional contact between the friction block and the side of the slide bar, enabling independent adjustment of the slide bars of each jaw without interference, so that complex workpieces can be clamped by a single person. Attached Figure Description
[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the chuck body in an embodiment; Figure 2 This is a schematic diagram of the chuck's structure in an embodiment; Figure 3 This is a schematic diagram of the chuck's structure in an embodiment; Figure 4 yes Figure 3 A partial structural explosion diagram.
[0018] In the attached diagram: 1: Chuck body, 2: Chuck claw, 3: Guide groove, 4: Slide rod, 5: Screw, 6: End plate, 60: Contact part, 61: Elastic element, 62: Stepped groove, 63: Friction block, 7: Baffle, 71: Hollow boss, 8: Rocker arm, 9: Groove body, 91: Shallow groove, 92: Deep groove. Detailed Implementation
[0019] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.
[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 limiting this invention.
[0021] In the description of this invention, if there are words such as "several", they mean one or more, "multiple" means two or more, "greater than", "less than", "exceeding" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself.
[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.
[0023] Reference Figures 1 to 4 The following are several embodiments of a chuck device and clamping method for a CNC machine tool according to the present invention.
[0024] Embodiments of the present invention provide a chuck device for a CNC machine tool, such as... Figures 1 to 4 As shown, the chuck includes a chuck body 1 and chuck jaws 2. The chuck jaws 2 are arranged in a circumferential array along the axis of the chuck body 1, and the chuck jaws 2 are movably connected to move synchronously towards or away from the axis of the chuck body 1. The chuck jaws 2 include: The guide grooves 3 are arranged in two sets symmetrically along the width direction, and the extension direction of the guide grooves 3 is parallel to the movement direction of the claw 2. The adjustment assembly has two slide rods 4 and at least one screw 5. The slide rods 4 are slidably disposed in the guide groove 3, and the screw 5 is rotatably disposed in the pawl 2 and is perpendicular to the slide rods 4. The locking assembly has an end plate 6, a baffle 7, and a rocker arm 8. The side of the pawl 2 is provided with a groove 9. The end plate 6 is disposed in the groove 9 and the groove 9 is covered by the baffle 7. One end of the screw 5 passes through the end plate 6 and the baffle 7 and is detachably connected to the rocker arm 8. The end plate 6 is provided with a threaded hole, which is connected to the thread on the screw 5. The locking assembly is configured to have a first working state and a second working state. The locking assembly drives the end plate 6 to move by rotating the screw 5, so that the end plate 6 abuts against the outer wall of the slide rod 4 in the first working state and separates from the slide rod 4 in the second working state.
[0025] In this embodiment, the slide bar is made of high-strength alloy steel, and its cross-sectional shape can be rectangular or irregular with guide ribs to resist torsion. The screw surface is provided with fine threads, such as M8×1.25, to provide more precise displacement control and greater locking force. During operation, the operator identifies the plane or the surface to be positioned on the workpiece, and drives the end plate to move backward by inserting the rocker arm and rotating the screw, thus separating it from the slide bar, i.e., switching to the second working state. Pushing or pulling back the slide bar so that the length of its end protruding from the chuck jaw matches the workpiece to be clamped surface, and then rotating the rocker arm in the opposite direction drives the end plate to move forward, pressing tightly against the side wall of the slide bar, i.e., switching to the first working state and locking the slide bar. Driving the chuck body, the three chuck jaws move synchronously towards the axis of the chuck body, where the adjusted slide bar precisely abuts against the workpiece plane, and the other chuck jaws or slide bar abut against the workpiece arc surface, completing the clamping.
[0026] This embodiment integrates independently adjustable and lockable sliding rods into the jaws, enabling a traditional three-jaw chuck to precisely position workpieces on flat or irregular outer surfaces without requiring fixture replacement. The synchronous radial movement function of the jaws themselves remains intact, allowing for automatic centering even on curved surfaces of the workpiece. This preserves the automatic centering function, achieving a combination of positioning and centering. Furthermore, all adjustment and locking mechanisms are built into the jaws, occupying no additional space and maintaining the chuck's overall integrity.
[0027] In an optional embodiment, such as Figure 2 and Figure 4 As shown, the groove 9 has a shallow groove 91 and a deep groove 92 that communicate with the guide groove 3. The shallow groove 91 is used to accommodate the end plate 6, and the deep groove 92 is used to allow the end plate 6 to abut against the side of the slide rod 4. In this embodiment, the groove is machined by milling. The structure of the shallow and deep grooves realizes the accommodation and guidance of the end plate, and ensures that the force of the end plate can be effectively transmitted to the slide rod, resulting in good structural rigidity.
[0028] In an optional embodiment, such as Figure 4As shown, the end plate 6 has a main body and a contact part 60. The main body is disposed in the shallow groove 91, and the contact part 60 is disposed in the deep groove 92. The contact part is located between the main body and the slide rod 4 and contacts the side of the slide rod 4.
[0029] In this embodiment, the main body is responsible for transmission and the contact part is responsible for clamping. The two can be manufactured and replaced separately, which reduces manufacturing difficulty and maintenance costs. The main body and the contact part can be connected by threads, pins, or keys.
[0030] In an optional embodiment, such as Figure 3 and Figure 4 As shown, the threaded hole is provided on the main body, and the screw 5 is threadedly engaged with the threaded hole on the main body. One end of the screw 5 extends to connect with the rocker arm 8, and the other end is rotatably supported in the pawl 2 by a bearing structure, so that when the screw 5 is rotated, the end plate 6 moves along the axial direction of the screw 5. The bearing structure can be a standard rolling bearing or a simple sliding bearing sleeve to ensure smooth screw rotation and generate only rotational motion, which is then converted into translational motion and transmitted to the end plate.
[0031] In an optional embodiment, such as Figure 4 As shown, an elastic element 61 is provided between the main body and the contact portion 60, so that the contact portion 60 constantly presses against the side of the slide rod 4, providing a preload force. The elastic element is a compression spring, and its preload force needs to be calculated and determined experimentally. Generally, it should generate a static friction force of approximately 1.5-2 times the weight of the slide rod and the workpiece on it. For example, if the weight of the slide rod assembly is estimated to be 1 kg, the spring preload force should ensure that the friction force between the contact portion and the slide rod is around 2 N, which is both anti-slip and easily overcome.
[0032] In this embodiment, when fully unlocked, i.e. in the second working state, the elastic element still pushes the contact part to press the slide bar, providing a certain frictional resistance. This frictional resistance is sufficient to prevent the slide bar from sliding due to its own weight or slight vibration, which facilitates fine-tuning of the length, but is less than the force required for manual adjustment, thus achieving temporary positioning. At the same time, the pre-tightening force can eliminate the transmission gap between the components, making the locking process faster and smoother.
[0033] In an optional embodiment, such as Figure 4As shown, the contact portion 60 is provided with a through stepped groove 62 and a friction block 63 disposed in the stepped groove 62. The stepped groove 62 is provided with a first step of relatively large size and a second step of relatively small size. The first step is located at one end adjacent to the main body, and the second step is located at one end adjacent to the slide rod 4. The friction block 63 has a guide portion and a friction abutment end. The guide portion is adapted to and movably connected to the inner contour surface of the first step. The friction abutment end passes through the second step and abuts against the side of the slide rod 4. The elastic member 61 is disposed between the main body and the guide portion.
[0034] In this embodiment, the friction block, as a wear-prone component, is made of a more wear-resistant material, such as brass or polyoxymethylene (POM). This material is wear-resistant and does not damage the slide bar; after wear, only the friction block needs to be replaced, not the entire end plate. The stepped groove structure distributes the enormous pressure during locking onto the main body of the contact area, preventing localized plastic deformation.
[0035] In an optional embodiment, such as Figure 1 and 2 As shown, the friction contact end has a rounded chamfer or bevel in the extending direction of the guide groove 3, so that when the slide rod 4 is inserted into the guide groove 3, the contact chamfer or bevel pushes the contact part back into the groove 9. The rounded chamfer or bevel of the friction contact end allows the slide rod to be smoothly guided in during installation or replacement without jamming with the end plate, improving the convenience of assembly.
[0036] In an optional embodiment, such as Figure 3 and Figure 4 As shown, the baffle 7 has a hollow boss 71 at the end of the screw 5. The hollow boss 71 is coaxially arranged with the screw 5. The rotating end of the rocker arm 8 is located inside the hollow boss 71 and is movably connected along the axial direction. The rotating end of the rocker arm 8 is detachably sleeved with the end of the screw 5 through a spline or non-circular cross-section, so that a transmission connection is achieved when the rocker arm 8 is pushed in and the connection is broken when it is pulled out. The rocker arm in this embodiment is a quick-connect rocker arm, which can achieve a transmission connection with the end of the screw by pushing it in. The use of a spline or non-circular cross-section (such as a hexagon) allows for high torque transmission and is not prone to slippage. This rocker arm requires little operating space, has a reliable connection, and can be removed when not in use to avoid interference, thus improving operational safety and convenience.
[0037] On the other hand, embodiments of the present invention also provide a clamping method for a chuck device of a CNC machine tool, such as... Figures 1 to 4 As shown, the following steps are achieved using a chuck device of a CNC machine tool in one or more alternative embodiments as described above: Place the workpiece axially into the center of the chuck body 1; Based on the shape characteristics of the workpiece's outer surface, determine the position of the slide bar 4 that needs to be adjusted, including: identifying the position of the jaw 2 corresponding to the outer wall of the workpiece's plane, and determining the slide bar 4 on the jaw 2 that needs to contact the outer wall of the plane; the operator does not need to adjust all the slide bars, but only operates on the slide bars that contact the special surface of the workpiece (such as a plane). For example, for a cylindrical workpiece with a single plane, only one or two slide bars on the jaw that is facing the plane need to be adjusted. By controlling the rotation of the corresponding screw 5 by the rocker arm 8, the locking assembly is switched to the second working state, the lock on the slide rod 4 is released, and the extension length of the slide rod 4 is adjusted so that its end can fully contact the outer wall of the plane. When adjusting the extension length of the slide rod 4, the preload provided by the elastic element 61 is used to keep the position of the slide rod 4 stable and prevent the slide rod 4 from moving accidentally during the adjustment process. When the locking assembly is switched to the second working state, the main body of the end plate 6 is retracted, and the maximum locking force is released. At this time, the slide rod is in a "sliding but damped" state. The operator can easily push the slide rod 4 to the desired position by hand. However, once the hand is released, the friction generated by the preload will immediately prevent it from sliding. This solves the problem of easy loosening of the adjusting screw and accidental movement of the slide rod in the traditional adjustment scheme. The operator can use a vernier caliper to measure the extension length of the slide rod or use the slide rod to lightly touch the workpiece plane for comparison and then make fine adjustments without worrying about the slide rod shifting when the hand is released. By controlling the screw 5 to rotate in the reverse direction via the rocker arm 8, the locking assembly is switched to the first working state, locking the position of the slide bar 4; through the transmission of the screw 5, a huge mechanical force is generated, which tightly presses the end plate 6 (through the friction block) onto the slide bar 4 to achieve fixation; At this point, the workpiece has been pre-positioned (precisely supported by a sliding rod on the flat surface, and contacted by a jaw or other sliding rod on the arc surface). Then, the automatic centering function of the chuck is activated to retract the jaws, and the three jaws 2 are simultaneously controlled to retract towards the axis of the chuck body 1 to stably clamp the workpiece.
[0038] In an optional embodiment, when the workpiece has multiple irregular outer surfaces, independently adjusting the extension length of the slide bar on different jaws includes: Each slide bar 4 that needs to contact the outer surface of the workpiece is individually adjusted. The operator examines the workpiece and identifies all special surfaces that need to contact the end of the slide bar, such as two angled planes, a plane and a curved surface, etc. Temporary positioning is provided through the frictional contact between the friction block 63 and the side of the slide bar 4, such as: At the first jaw position of the chuck body, adjust the slide bar at the first jaw position so that its length matches one of the inclined surfaces of the workpiece, and use the preload to temporarily fix the slide bar; then at the second jaw position, adjust the slide bar on the second jaw so that its length matches another plane of the workpiece. There is no need to worry about the previously adjusted slide bar of the first jaw changing. Adjust all the slide bars that need to be adjusted in sequence. After all slide bars 4 have been initially adjusted, the operator can check each dimension again. After confirming that there are no errors, the operator can use the rocker arm 8 to switch each locking component to the first working state in sequence for final locking. This final locking step avoids accidental collisions with another locked slide bar when adjusting one slide bar. After locking each slide bar 4 one by one, the chuck 2 is then synchronously controlled to retract towards the axis of the chuck body 1 to stably clamp the workpiece.
[0039] This implementation provides a temporary positioning adjustment process through the frictional contact between the friction block and the side of the slide bar, which enables independent adjustment of the slide bars of each jaw without interference, allowing complex workpieces to be clamped by a single person.
[0040] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.
Claims
1. A chuck device for a CNC machine tool, comprising a chuck body (1) and jaws (2), wherein the jaws (2) are arranged in a circumferential array along the axis of the chuck body (1), and the jaws (2) are movably connected to the axis of the chuck body (1) synchronously moving closer to or further away from it, characterized in that, The jaw (2) includes: The guide grooves (3) are symmetrically distributed in two sets along the width direction, and the extension direction of the guide grooves (3) is parallel to the movement direction of the claw (2) where they are located; The adjustment assembly has two slide rods (4) and at least one screw (5), the slide rods (4) are slidably disposed in the guide groove (3), and the screw (5) is rotatably disposed in the pawl (2) and is perpendicular to the slide rods (4); The locking assembly has an end plate (6), a baffle (7), and a rocker arm (8). The side of the pawl (2) is provided with a groove (9). The end plate (6) is disposed in the groove (9) and the groove (9) is covered by the baffle (7). One end of the screw (5) passes through the end plate (6) and the baffle (7) and is detachably connected to the rocker arm (8). The end plate (6) is provided with a threaded hole, which is connected to the thread on the screw (5) so that the locking assembly is set to have a first working state and a second working state. The locking assembly drives the end plate (6) to move by rotating the screw (5), so that the end plate (6) abuts against the outer wall of the slide rod (4) in the first working state and separates from the slide rod (4) in the second working state.
2. The chuck device for a CNC machine tool according to claim 1, characterized in that: The groove (9) has a shallow groove (91) and a deep groove (92) that are connected to the guide groove (3). The shallow groove (91) is used to accommodate the end plate (6), and the deep groove (92) is used to allow the end plate (6) to abut against the side of the slide rod (4).
3. The chuck device for a CNC machine tool according to claim 2, characterized in that: The end plate (6) has a main body and a contact part (60). The main body is disposed in the shallow groove (91), and the contact part (60) is disposed in the deep groove (92). The contact part (60) is located between the main body and the slide rod (4) and contacts the side of the slide rod (4).
4. The chuck device for a CNC machine tool according to claim 3, characterized in that: The threaded hole is provided on the main body, and the screw (5) is threadedly engaged with the threaded hole on the main body. One end of the screw (5) extends to connect with the rocker arm (8), and the other end is rotatably supported in the pawl (2) through a bearing structure, so that when the screw (5) is rotated, the end plate (6) moves along the axial direction of the screw (5).
5. The chuck device for a CNC machine tool according to claim 3, characterized in that: An elastic element (61) is provided between the main body and the contact part (60), so that the contact part (60) is constantly pressed against the side of the slide rod (4) to provide preload.
6. The chuck device for a CNC machine tool according to claim 5, characterized in that: The contact portion (60) is provided with a through stepped groove (62) and a friction block (63) disposed in the stepped groove (62). The stepped groove (62) is provided with a first step of relatively large size and a second step of relatively small size. The first step is located at one end adjacent to the main body, and the second step is located at one end adjacent to the slide rod (4). The friction block (63) has a guide portion and a friction abutment end. The guide portion is adapted to and movably connected to the inner contour surface of the first step. The friction abutment end passes through the second step and abuts against the side of the slide rod (4). The elastic member (61) is disposed between the main body and the guide portion.
7. The chuck device for a CNC machine tool according to claim 6, characterized in that: The friction contact end is provided with a rounded chamfer or bevel in the extension direction of the guide groove (3), so that when the slide rod (4) is inserted into the guide groove (3), the contact chamfer or bevel will push the contact part (60) back into the groove (9).
8. The chuck device for a CNC machine tool according to claim 1, characterized in that: The baffle (7) is provided with a hollow boss (71) at the end of the screw (5). The hollow boss (71) is coaxial with the screw (5). The rotating end of the rocker (8) is located inside the hollow boss (71) and is movably connected along the axial direction. The rotating end of the rocker (8) is detachably sleeved with the end of the screw (5) through a spline or non-circular cross section, so that the transmission connection is realized when the rocker (8) is pushed in and the connection is disconnected when it is pulled out.
9. A clamping method for a chuck device of a CNC machine tool, characterized in that... The following steps are achieved using a chuck device for a CNC machine tool as described in any one of claims 1-8: Place the workpiece axially into the center of the chuck body (1); Based on the shape characteristics of the outer surface of the workpiece, determine the position of the slide bar (4) that needs to be adjusted, including: identifying the position of the chuck (2) corresponding to the outer wall of the workpiece plane, and determining the slide bar (4) on the chuck (2) that needs to contact the outer wall of the plane. By controlling the rotation of the corresponding screw (5) by the rocker arm (8), the locking assembly is switched to the second working state, the lock on the slide rod (4) is released, and the extension length of the slide rod (4) is adjusted so that its end can fully contact the outer wall of the plane. When adjusting the extension length of the slide rod (4), the preload provided by the elastic element (61) is used to keep the position of the slide rod (4) stable and prevent the slide rod (4) from moving accidentally during the adjustment process. By controlling the screw (5) to rotate in the opposite direction by the rocker arm (8), the locking assembly is switched to the first working state and the slide bar (4) is locked. Synchronous control of the three jaws (2) to retract towards the axis of the chuck body (1) to stably clamp the workpiece.
10. The clamping method of the chuck device for a CNC machine tool according to claim 9, characterized in that, When the workpiece has multiple irregular outer surfaces, the extension length of the slide bar (4) on different jaws (2) can be adjusted independently, including: Each slide bar (4) that needs to contact the outer surface of the workpiece is individually adjusted; Temporary positioning is provided by frictional contact between the friction block (63) and the side of the slide bar (4); After locking each slide bar (4) one by one, the chuck (2) is controlled to retract toward the axis of the chuck body (1) in a synchronous manner to stably clamp the workpiece.