Chuck clamp with adjustable clamping angle and angle adjusting method

Abstract

The invention relates to the technical field of machine tool clamps, in particular to a chuck clamp with an adjustable clamping angle and an angle adjusting method. Comprising a chuck body and movable clamping jaws, the multiple movable clamping jaws which are annularly and evenly distributed are arranged on the chuck body, a first step and a second step are arranged on the end face of each movable clamping jaw, the multiple movable clamping jaws can be close to or away from the center of the chuck body from the end of the chuck body, and an adjustable clamping plate is movably connected to the positions, close to the center of the chuck body, of the movable clamping jaws. The clamping angle of the adjustable clamping plate is adjusted through an angle adjusting system, the angle adjusting system comprises an adjusting bolt, a controller and a human-computer interface, the adjusting bolt is in threaded connection with the adjustable clamping plate and the movable clamping jaw, and the adjusting bolt is driven by a micro motor. According to the invention, a workpiece with a tapered excircle can be effectively clamped, the inclination angle of the chuck fixture can be accurately controlled, the clamping is simpler and more convenient, the clamping time is shortened, and the workpiece processing quality is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool fixtures, and particularly to a chuck fixture with adjustable clamping angle and an angle adjustment method. Background Art

[0002] In the field of mechanical manufacturing, horizontal lathes are widely used for the external circle machining of workpieces. Generally, a conventional three-jaw chuck is used to clamp one end of the workpiece, and the other end is fixed by a tooling against the inner hole. This method can provide stability when machining workpieces with non-tapered external circles, but for workpieces with tapers, especially those that also require heat treatment, the conventional three-jaw chuck cannot provide a stable clamping force. In the prior art, there are mainly two common machining methods for workpieces with tapered external circles: First, the taper of the workpiece's external circle is machined last. First, use a common three-jaw chuck to clamp one end of the workpiece, then use a tooling to top the inner hole at the other end to machine the external circle. After machining the external circle, perform heat treatment, and finally finish machining the external taper surface. However, this will result in more chip removal on the machined external taper surface than other parts, causing the hardness of the machined taper surface to be lower than other parts of the workpiece; Second, the method of adding gaskets between the workpiece and the chuck jaws. However, the thickness, shape, and installation accuracy of the gaskets have a greater impact on the machining results. Since the installation and adjustment of the gaskets require relatively high operating skills, there may be significant differences in the machining results of different batches or different operators, making it difficult to ensure the consistency of machining. Moreover, manual adjustment wastes time and reduces production efficiency.

[0003] Therefore, the present invention proposes a chuck fixture with adjustable clamping angle, so that workpieces with tapered external circles can be effectively clamped, the inclination angle of the chuck fixture can be accurately controlled, the clamping is more convenient, the clamping time is shortened, and the machining quality of the workpiece is guaranteed. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art, and to propose a chuck fixture with adjustable clamping angle and an angle adjustment method.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions: A chuck fixture with adjustable clamping angle, comprising a chuck body, movable jaws, and an angle adjustment system. A plurality of circumferentially evenly distributed movable jaws are arranged on the chuck body. The end face of the movable jaw is provided with a first step and a second step. The plurality of movable jaws can move synchronously along the outer edge of the chuck body in the radial direction and approach or move away from the center of the chuck body. The movable jaw is movably connected to an adjustable clamping plate near the center of the chuck body. The adjustable clamping plate adjusts its clamping angle by the angle adjustment system. The angle adjustment system includes an adjustment bolt, a controller, and a human-machine interface. The adjustment bolt is threadedly connected to the adjustable clamping plate and the movable jaw respectively. The adjustment bolt is driven by a micro motor, and the adjustment bolt drives the adjustable clamping plate to approach or move away from the center of the chuck body.

[0006] Further, the micro motor further includes a first micro motor and a second micro motor. The adjustment bolt includes a first adjustment bolt and a second adjustment bolt. The first adjustment bolt and the second adjustment bolt respectively penetrate through the first step and the second step of the movable jaw. The first micro motor and the second micro motor are respectively arranged on the table surface of the first step and the table surface of the second step. The output ends of the first micro motor and the second micro motor are respectively connected to the first adjustment bolt and the second adjustment bolt.

[0007] Further, the angle adjustment system further includes an angle sensor. The angle sensor monitors the clamping angle between the adjustable clamping plate and the workpiece. The angle sensor is electrically connected to the controller.

[0008] Further, a disc spring is arranged between the top panel of the adjustable clamping plate and the bottom panel of the movable jaw.

[0009] Further, the material of the adjustable clamping plate is a hard or soft material. The cross section of the adjustable clamping plate is square, arc-shaped or other shapes.

[0010] Further, an angle adjustment method, including the chuck fixture with adjustable clamping angle described in any one of the above, includes the following steps: S1: Input the target angle in the human-machine interface. The target angle is transmitted to the controller. The angle between the outer inclined surface of the clamped workpiece and the central axis of the workpiece is the target angle. S2: According to the target angle, the controller calculates the number of turns that the first adjustment bolt and the second adjustment bolt need to rotate, and takes the angle between the adjustable clamping plate and the outer inclined surface of the clamped workpiece as the current angle. S3: The controller drives the first micro motor or the second micro motor to rotate, drives the first adjustment bolt or the second adjustment bolt to rotate, and changes the inclination angle of the adjustable clamping plate. S4: The angle sensor monitors the angle between the adjustable clamping plate and the clamped workpiece in real time. The controller continuously adjusts the rotation of the micro motor according to the feedback signal of the angle sensor until the target angle is reached, completing the closed-loop control; S5: After the machining is completed, the controller controls the corresponding first adjusting bolt or the second adjusting bolt to reverse, and the workpiece can be released.

[0011] Further, in the S3, when clamping a workpiece with a gradually decreasing end portion towards the middle, keep the first adjusting bolt stationary and rotate the second adjusting bolt closer to the center of the chuck body. When clamping a workpiece with a gradually increasing end portion towards the middle, keep the second adjusting bolt stationary and rotate the first adjusting bolt towards the center of the chuck body.

[0012] Further, according to an angle adjustment method as claimed in claim 7, characterized in that the number of turns of rotation of the first adjusting bolt or the second adjusting bolt is calculated based on the target angle, and the calculation expression is: , where N is the number of turns of rotation of the first adjusting bolt or the second adjusting bolt, ΔL is the length change of the first adjusting bolt or the second adjusting bolt between the adjustable clamping plate and the movable jaw, and P is the pitch of the adjusting bolt.

[0013] Further, the ΔL can be expressed as: , where ΔL is the length change of the first adjusting bolt or the second adjusting bolt between the adjustable clamping plate and the movable jaw, d is the horizontal distance between the first adjusting bolt or the second adjusting bolt and the rotation point connected to the adjustable clamping plate, and θ is the target angle.

[0014] Further, the angle sensor is a piezoelectric film sensor array, and the piezoelectric film sensor array is integrated on the surface of the adjustable clamping plate to monitor the coupling relationship between the clamping force distribution and the angle deflection in real time. The compensation model formula is established as: , where θ1 is the corrected angle, is the target angle, is the current angle, K is the dynamic gain coefficient, F i is the pressure value at the i-th measuring point, Δx, Δy are the deformation amounts of the adjustable clamping plate, represents the gradient of the pressure field in the x direction, represents the gradient of the pressure field in the y direction.

[0015] Compared with the existing technology, an adjustable clamping angle chuck fixture and an angle adjustment method provided by the present invention have the following advantages: 1. Through the angle adjustment system, the angle between the adjustable clamping plate and the bottom of the movable jaw is controlled, so that the adjustable clamping plate can accurately fit the outer conical surface of the workpiece, ensuring the stability and accuracy of clamping, and avoiding machining errors caused by improper clamping; 2. Automatic adjustment simplifies the clamping process and shortens the clamping time. The operator only needs to turn on the angle adjustment system and input the target angle, and the micro-motor drives the adjustment bolt to rotate up and down, then the clamping angle can be adjusted, significantly shortening the clamping time; 3. Elastic compensation: The set disc spring can provide elastic compensation during workpiece machining, absorb machining vibrations, and maintain a constant clamping force at the same time, ensuring that the workpiece will not be displaced or deformed during the machining process; 4. Wide application range: The adjustable clamping plate can be replaced with different materials and shapes to adapt to workpieces of different materials and can clamp workpieces of different shapes; 5. Simple structure, easy to disassemble, install and maintain, improving the availability of the equipment. Description of the Drawings

[0016] Figure 1 It is a three-dimensional structural schematic diagram of the chuck fixture of the present invention; Figure 2 It is the front view of the chuck fixture of the present invention; Figure 3 It is Figure 2 The sectional view taken along the line A-A in Figure 4 It is a schematic diagram of the angle adjustment system in the present invention; Figure 5 It is a schematic diagram of the closed-loop control of the angle adjustment system in the present invention; In the figure: 1. Chuck body, 2. Movable jaw, 3. First adjustment bolt, 4. First step, 5. Second adjustment bolt, 6. Second step, 7. Adjustable clamping plate, 8. Controller, 9. Human-machine interface, 10. First micro-motor, 11. Second micro-motor, 12. Angle sensor. Detailed Embodiment

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0019] Example 1. Refer to Figures 1-3 In this example, a chuck fixture with adjustable clamping angle includes a chuck body 1 and movable jaws 2. A plurality of circumferentially equally spaced movable jaws 2 are arranged on the chuck body 1. The end face of the movable jaw 2 is provided with a first step 4 and a second step 6. The plurality of movable jaws 2 can move synchronously along the outer edge of the chuck body 1 in the radial direction and approach or move away from the center of the chuck body 1. It further includes an angle adjustment system. The movable jaw 2 is movably connected to an adjustable clamping plate 7 near the center of the chuck body 1. The adjustable clamping plate 7 adjusts its clamping angle by the angle adjustment system. The angle adjustment system includes an adjustment bolt, a controller 8, and a human-machine interface 9. The adjustment bolt is threadedly connected to the adjustable clamping plate 7 and the movable jaw 2 respectively. The adjustment bolt is driven by a micro-motor, and the adjustment bolt drives the adjustable clamping plate 7 to approach or move away from the chuck body 1.

[0020] A plurality of grooves for the movement of the movable jaws 2 are formed on the chuck body 1. The mounting surface of the movable jaw 2 contacts the bottom of the groove on the chuck body 1. A driving mechanism is rotatably arranged on the bottom of the groove. When the driving mechanism rotates, it drives the movable jaw 2 to reciprocate radially along the chuck body 1.

[0021] Through the above arrangement, the angle adjustment system can adjust the inclination angle of the adjustable clamping plate 7 through the micro-motor, so that workpieces with a taper can be clamped. The human-machine interface 9 can input parameters and display the operation information of the chuck fixture, which is convenient and easy to use. In this embodiment, the chuck fixture is a three-jaw chuck.

[0022] Example 2. Continue to refer to Figures 1-3 , the micro-motor further includes a first micro-motor 10 and a second micro-motor 11. The adjustment bolt includes a first adjustment bolt 3 and a second adjustment bolt 5. The first adjustment bolt 3 and the second adjustment bolt 5 respectively penetrate through the first step 4 and the second step 6 of the movable jaw 2. The first micro-motor 10 and the second micro-motor 11 are respectively arranged on the table surface of the first step 4 and the table surface of the second step 6. The output ends of the first micro-motor 10 and the second micro-motor 11 are respectively connected to the first adjustment bolt 3 and the second adjustment bolt 5.

[0023] The connection between the first adjustment bolt 3 and the movable jaw 2 is a threaded connection. The connection between the second adjustment bolt 5 and the movable jaw 2 is also a threaded connection. The threaded connection can realize the fine adjustment and precise control of the adjustable clamping plate 7, and can ensure the firm and reliable connection between the adjustment bolt and the movable jaw 2. By rotating the adjustment bolt, the length change of the adjustment bolt can be precisely controlled, so as to realize the precise adjustment of the inclination angle of the adjustable clamping plate 7.

[0024] By driving the rotation of the adjusting bolt through the set micro-motor, the adjusting bolt drives the adjustable clamping plate 7 to form the same slope as the inclined surface of the workpiece, so as to stably clamp the tapered workpiece. For example, if we want to clamp a workpiece with an end gradually increasing towards the middle, first center the workpiece, drive the movable jaw 2 to the surface of the workpiece for initial clamping. At this time, we can keep the second adjusting bolt 5 stationary and rotate the first adjusting bolt 3 towards the center of the chuck body 1. The first adjusting bolt 3 drives one end of the adjustable clamping plate 7 to tightly press against the inclined surface of the workpiece, thus stably clamping the workpiece with an end gradually increasing towards the middle. When we want to loosen the adjustable clamping plate 7, we reverse the first adjusting bolt 3 and move the first adjusting bolt 3 away from the center of the chuck body 1, then we can loosen the clamping of the adjustable clamping plate 7 on the workpiece. On the contrary, if we want to clamp a workpiece with an end gradually decreasing towards the middle, we can keep the first adjusting bolt 3 stationary and rotate the second adjusting bolt 5 closer to the center of the chuck body 1. At this time, the second adjusting bolt 5 drives the other end of the adjustable clamping plate 7 to tightly press against the inclined surface of the workpiece, and we can also clamp the workpiece with an end gradually decreasing towards the middle. If we want to loosen the clamping of the workpiece, rotate the second adjusting bolt 5 counterclockwise, which can drive the adjustable clamping plate 7 away from the surface of the workpiece, thus loosening the clamping of the workpiece.

[0025] In order to enable the adjusting bolt to achieve an automated function, a first micro-motor 10 is connected to the upper end of the first adjusting bolt 3, and a second micro-motor 11 is connected to the upper end of the second adjusting bolt 5. The first micro-motor 10 and the second micro-motor 11 are respectively installed on the upper surfaces of the first step 4 and the second step 6 of the movable jaw 2. Through the drive of the micro-motors, there is no need for manual adjustment of the adjusting bolt. In some embodiments, the micro-motors are closed-loop stepper motors, which can drive the adjusting bolt to achieve fine adjustment of the adjustable clamping plate 7.

[0026] In Embodiment 3, in order to make the adjustment angle more accurate, the angle adjustment system is also provided with an angle sensor 12, and the sensor 12 is electrically connected to the controller 8. The angle sensor is installed on the adjustable clamping plate 7, which can real-time monitor the inclination angle of the adjustable clamping plate 7, that is, the current angle between the adjustable clamping plate 7 and the clamped workpiece, and then transmit this angle to the controller 8 for comparison with the target angle, so as to automatically adjust the adjusting bolt to make the inclination angle of the adjustable clamping plate 7 consistent with the target angle.

[0027] In Embodiment 4, in order to reduce the vibration and impact generated by the workpiece during the machining process, a disc spring is provided between the top panel of the adjustable clamping plate 7 and the bottom panel of the movable jaw 2. The disc spring is a prior art, which can mainly compensate for the small displacement caused by the change of the workpiece clamping force through its own elastic deformation, and can also reduce the vibration transmitted to the chuck body 1 and the clamped workpiece, avoiding the displacement of the clamped workpiece or damage to the machining surface.

[0028] Embodiment 5. To clamp workpieces made of various materials, the adjustable clamping plate 7 is made of hard or soft materials, and the cross-section of the adjustable clamping plate 7 is square or arc-shaped.

[0029] During the workpiece machining process, the workpiece is composed of different materials. The adjustable clamping plate 7 can select the corresponding material to avoid damaging the workpiece. It can also be switched to the corresponding different shape according to the appearance shape of the workpiece. For example, if the surface of the workpiece is cylindrical, the adjustable clamping plate 7 is replaced with an arc-shaped clamping plate. Since the side of the arc-shaped clamping plate close to the workpiece is in the shape of an arc that fits the surface of the workpiece, it can clamp the workpiece more firmly. If the workpiece is of other shapes, then it is replaced with other adjustable clamping plates 7 that can fit the surface of the workpiece.

[0030] Embodiment 6. An angle adjustment method, referring to Figures 3-4 , including the chuck fixture with adjustable clamping angle described in any one of the above, characterized by including the following steps: S1: Input the target angle in the human-machine interface 9. The target angle is transmitted to the controller 8, and the angle between the outer inclined surface of the clamped workpiece and the central axis of the workpiece is the target angle; S2: According to the target angle, the controller 8 calculates the number of turns that the first adjusting bolt 3 and the second adjusting bolt 5 need to rotate, with the angle between the adjustable clamping plate 7 and the outer inclined surface of the clamped workpiece as the current angle; S3: The controller 8 drives the first micro-motor 10 or the second micro-motor 11 to rotate, driving the first adjusting bolt 3 or the second adjusting bolt 5 to rotate, and changing the inclination angle of the adjustable clamping plate 7; S4: The angle sensor 12 monitors the angle between the adjustable clamping plate 7 and the clamped workpiece in real time. The controller 8 continuously adjusts the rotation of the micro-motor according to the feedback signal of the angle sensor 12 until the target angle is reached, completing the closed-loop control; S5: After the machining is completed, the controller controls the corresponding first adjusting bolt 3 or the second adjusting bolt 5 to reverse, and the workpiece can be released.

[0031] In this embodiment, a closed-loop control method is used to control the angle adjustment system. As Figure 5 shown, first give the controller 8 a target angle. The angle sensor 12 monitors the angle between the adjustable clamping plate 7 and the clamped workpiece, that is, the current angle. Through the calculation of the controller 8, the current angle signal is transmitted to the micro-motor, and the micro-motor rotates forward or backward, rotating the adjusting bolt closer to or farther from the center of the chuck body, so as to adjust the clamping angle between the adjustable clamping plate 7 and the clamped workpiece.

[0032] In S3, when clamping a workpiece with a gradually decreasing clamping end towards the middle, keep the first adjusting bolt 3 stationary and rotate the second adjusting bolt 5 closer to the center of the chuck body 1. When clamping a workpiece with a gradually increasing clamping end towards the middle, keep the second adjusting bolt 5 stationary and rotate the first adjusting bolt 3 towards the center of the chuck body 1.

[0033] Calculate the number of turns of rotation of the first adjusting bolt 3 or the second adjusting bolt 5 according to the target angle, and its calculation expression is: , where N is the number of turns of rotation of the first adjusting bolt 3 or the second adjusting bolt 5, ∆L is the length change of the first adjusting bolt 3 or the second adjusting bolt 5 between the adjustable clamping plate 7 and the movable jaw 2, and P is the pitch of the adjusting bolt.

[0034] The ∆L can be expressed as: , where ∆L is the length change of the first adjusting bolt 3 or the second adjusting bolt 5 between the adjustable clamping plate 7 and the movable jaw 2, d is the horizontal distance between the first adjusting bolt 3 or the second adjusting bolt 5 and the rotation point connected to the adjustable clamping plate 7, and θ is the target angle.

[0035] In this embodiment, we set the target angle θ to 5°, and the horizontal distance d between the first adjusting bolt 3 and the rotation point connected to the adjustable clamping plate 7 is 100 mm. Then the length change of the first adjusting bolt 3 is: , After calculating the length change, the number of turns of rotation of the first adjusting bolt 3 can be calculated, and then the relevant parameters of the first micro-motor can be calculated, providing a basis for the design and control of the micro-motor system.

[0036] Then according to the formula , substituting the value of ∆L, and the pitch P of the first adjusting bolt 3 is 1 mm. Then the number of turns of rotation of the first adjusting bolt 3 is: , It shows that the first adjusting bolt 3 needs to rotate 8.75 turns to move 8.75 mm.

[0037] Similarly, the number of turns of rotation of the second adjusting bolt 5 can be calculated.

[0038] During the clamping process, continue to refer to Figure 5, the angle sensor 12 always monitors the clamping angle between the adjustable clamping plate 7 and the workpiece, and then feeds it back to the controller 8. The comparator in the controller 8 compares the actual clamping angle with the target angle and continuously adjusts it to always be consistent with the target angle. In order to control the bolt torque from exceeding the limit, a micro pressure sensor can also be embedded inside the adjustable clamping plate 7. The micro pressure sensor is signal-connected to the controller 8, giving the controller 8 a certain clamping force threshold. The micro pressure sensor transmits the clamping force signal to the controller 8, automatically switches the clamping force threshold according to the workpiece material (such as aluminum / steel). When the controller receives that the micro pressure sensor reaches the clamping force threshold, it controls the micro motor to stop rotating, and finally firmly clamps the workpiece to improve the clamping stability during workpiece processing.

[0039] In another embodiment, the angle sensor is a piezoelectric film sensor. For workpieces with high clamping accuracy requirements, a piezoelectric film sensor is integrated on the surface of the adjustable clamping plate 7. The piezoelectric film sensors are arranged in a 5×5 array with a spacing of 2 mm to cover the entire contact surface of the adjustable clamping plate 7, and the pressure distribution at the contact points between the adjustable pressure plate and the workpiece is detected in real time. The corrected clamping angle can be expressed as: , where, θ1 is the corrected angle, is the target angle, is the current angle, K is the dynamic gain coefficient, F i is the pressure value at the i-th measurement point, Δx and Δy are the deformation amounts of the clamping plate of the adjustable clamping plate 7, represents the gradient of the pressure field in the x direction, represents the gradient of the pressure field in the y direction, , both represent the local change rates of the clamping force in the x and y directions, reflecting the stress concentration areas of the clamping plate, and are calibrated through experiments.

[0040] The specific implementation steps are as follows: Assume the target angle is 30°, the current angle is 25°, and the dynamic gain coefficient K = 0.05. Through experimental calibration, the piezoelectric film sensor array measures that the pressure F 34 at the measurement point in the 3rd row and 4th column = 12 N, the pressure F 32 at the measurement point in the 3rd row and 2nd column = 8 N, the pressure F 24 at the measurement point in the 2nd row and 4th column = 10 N (used to calculate the gradient in the y direction). In this embodiment, the deformation amounts Δx and Δy of the clamping plate of the adjustable clamping plate 7 are measured by the sensors and can be represented by the sensor spacing, so Δx = 4 mm and Δy = 2 mm. Then the gradient in the x direction , The gradient in the y direction , Then sum the contributions of all measurement points (n = 1): , Finally, calculate the corrected angle: , We can continue to iterate through the closed-loop control system to update the current angle , Recalculate the corrected angle according to the formula , According to the calculated corrected angle, compare it with the target angle, and continue to loop and iterate until the current angle iterates close to the target angle, then the adjusting bolt will no longer be adjusted.

[0041] Embodiment 7. The technological process of machining a cylindrical workpiece using a chuck fixture with an adjustable clamping angle is as follows: 1. Blanking; 2. Flaw detection; 3. Rough turning: Rough turn the inner hole according to the drawing requirements, leaving a 1-mm allowance on each side; Rough turn the outer taper, leaving a 1-mm allowance on each dimension on each side; 4. Drilling; 5. Heat treatment; 6. Finish turning: Use the adjustable clamping plate 7 to clamp the outer taper surface, and finish turn the inner hole and the outer circle. Using the chuck fixture of the present invention for clamping and machining makes the allowances left on each part of the rough-turned shape of the cylindrical workpiece consistent, the heat treatment uniform, and the hardness also consistent. The chip removal amount during finish turning is consistent, ultimately ensuring that the hardness of the outer surface of the cylindrical workpiece is consistent.

[0042] In the prior art, because workpieces with a taper cannot be clamped well, the technological process is to first perform heat treatment and then machine the taper surface, which will cause the hardness of the end with a large chip removal amount on the machined taper surface to be lower than that of other parts. Now, after using the chuck fixture with an adjustable clamping angle, first rough turn the outer taper and then perform heat treatment, ultimately ensuring that the hardness of the outer surface of the workpiece is consistent.

[0043] The working principle of the present invention: First, select an adjustable clamping plate 7 that matches the shape of the workpiece according to the workpiece, install the adjustable clamping plate 7 on the movable jaw 2. After installation, align the center of the workpiece with the center of the chuck body 1. First, move the movable jaw 2 along the groove towards the center of the chuck body 1 to determine the clamping angle of the adjustable clamping plate 7 with respect to the workpiece, that is, the target angle. Input the target angle into the human-machine interface 9. The controller 8 receives the information and then controls the output end of the micro motor to work. The output end of the micro motor controls the corresponding first adjusting bolt 3 or the second adjusting bolt 5 to approach the center of the chuck body 1, thereby adjusting the inclination angle of the adjustable clamping plate 7 to better clamp the workpiece with a taper. During the working process, the angle sensor 12 continuously monitors the clamping angle between the adjustable clamping plate 7 and the clamped workpiece and feeds the data back to the controller 8. The controller 8 controls the first adjusting bolt 3 or the second adjusting bolt 5 for fine adjustment to complete the closed-loop control. When it is necessary to loosen the adjustable clamping plate 7, the controller controls the corresponding first adjusting bolt 3 or the second adjusting bolt 5 to move away from the center of the chuck body 1, and the clamped workpiece can be loosened.

[0044] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A chuck fixture with adjustable clamping angle, comprising a chuck body (1), movable jaws (2), and an angle adjustment system. A plurality of circumferentially evenly distributed movable jaws (2) are arranged on the chuck body (1). The end face of the movable jaw (2) is provided with a first step (4) and a second step (6). The plurality of movable jaws (2) can synchronously move along the outer edge of the chuck body (1) in the radial direction and move closer to or away from the center of the chuck body. It is characterized in that, The movable jaw (2) is movably connected with an adjustable clamping plate (7) near the center of the chuck body. The clamping angle of the adjustable clamping plate (7) is adjusted by the angle adjustment system. The angle adjustment system includes an adjustment bolt, a controller (8) and a human-machine interface (9). The adjustment bolt is threadedly connected with the adjustable clamping plate (7) and the movable jaw (2) respectively. The adjustment bolt is driven by a micro-motor, and the adjustment bolt drives the adjustable clamping plate (7) to approach or move away from the center of the chuck body (1).

2. The chuck fixture with adjustable clamping angle according to claim 1, characterized in that: The micro-motor includes a first micro-motor and a second micro-motor. The adjustment bolt includes a first adjustment bolt (3) and a second adjustment bolt (5). The first adjustment bolt (3) and the second adjustment bolt (5) respectively penetrate through the first step (4) and the second step (6) of the movable jaw (2). The first micro-motor (10) and the second micro-motor (11) are respectively arranged on the table surface of the first step (4) and the table surface of the second step (6). The output ends of the first micro-motor (10) and the second micro-motor (10) are respectively connected with the first adjustment bolt (3) and the second adjustment bolt (5).

3. An adjustable clamping angle chuck fixture according to claim 2, characterized in that: The angle adjustment system further includes an angle sensor (12). The angle sensor (12) monitors the clamping angle between the adjustable clamping plate (7) and the workpiece. The angle sensor (12) is electrically connected with the controller (8).

4. An adjustable clamping angle chuck fixture according to claim 1, characterized in that: A disc spring is arranged between the top panel of the adjustable clamping plate (7) and the bottom panel of the movable jaw (2).

5. A chuck fixture with adjustable clamping angle according to claim 4, characterized in that: The material of the adjustable clamping plate (7) is a hard or soft material, and the cross-section of the adjustable clamping plate (7) is square or arc-shaped.

6. An angle adjustment method, comprising a chuck fixture with adjustable clamping angle according to any one of claims 1-5, characterized in that, It includes the following steps: S1: Input the target angle in the human-machine interface (9). The target angle is transmitted to the controller (8). The angle between the outer inclined surface of the clamped workpiece and the central axis of the workpiece is the target angle. S2: According to the target angle, the controller (8) calculates the number of turns that the first adjustment bolt (3) and the second adjustment bolt (5) need to rotate, and takes the angle between the adjustable clamping plate (7) and the outer inclined surface of the clamped workpiece as the current angle. S3: The controller (8) drives the first micro-motor (10) or the second micro-motor (11) to rotate, drives the first adjustment bolt (3) or the second adjustment bolt (5) to rotate, and changes the inclination angle of the adjustable clamping plate (7). S4: The angle sensor (12) monitors the angle between the adjustable clamping plate (7) and the clamped workpiece in real time. The controller (8) continuously adjusts the rotation of the micro-motor according to the feedback signal of the angle sensor (12) until the target angle is reached, and the closed-loop control is completed. S5: After the processing is completed, the controller (8) controls the corresponding first adjustment bolt (3) or the second adjustment bolt (5) to reverse, and the workpiece can be loosened.

7. The angle adjustment method according to claim 6, characterized in that, In step S3, when clamping a workpiece with a gradually decreasing end part towards the middle, keep the first adjustment bolt (3) stationary and rotate the second adjustment bolt (5) towards the center of the chuck body (1). When clamping a workpiece with a gradually increasing end part towards the middle, keep the second adjustment bolt (5) stationary and rotate the first adjustment bolt (3) towards the center of the chuck body (1).

8. A method for angle adjustment according to claim 7, characterized in that, Calculate the number of turns of rotation of the first adjusting bolt (3) or the second adjusting bolt (5) according to the target angle, and its calculation expression is: , where N is the number of turns of rotation of the first adjusting bolt (3) or the second adjusting bolt (5), ∆L is the length change of the first adjusting bolt (3) or the second adjusting bolt (5) between the adjustable clamping plate (7) and the movable jaw (2), and P is the pitch of the adjusting bolt.

9. A method for angle adjustment according to claim 7, characterized in that, The described ∆L can be expressed as: , where ∆L is the length change of the first adjusting bolt (3) or the second adjusting bolt (5) between the adjustable clamping plate (7) and the movable jaw (2), d is the horizontal distance between the first adjusting bolt (3) or the second adjusting bolt (5) and the connection rotation point of the adjustable clamping plate (7), and θ is the target angle.

10. A method for adjusting an angle according to claim 6, characterized in that The angle sensor (12) is a piezoelectric thin film sensor array, which is integrated on the surface of the adjustable clamping plate (7) to monitor the coupling relationship between the clamping force distribution and the angle deflection in real time. The compensation model formula is established as follows: ， Among them, θ1 is the corrected angle, is the target angle, is the current angle, K is the dynamic gain coefficient, F i is the pressure value of the i-th measurement point, Δx and Δy are the deformation amounts of the adjustable splint (7), represents the gradient of the pressure field in the x direction, represents the gradient of the pressure field in the y direction.

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