A motor-driven turntable control method and system

Abstract

The present application discloses a motor-driven turntable control method and system, and relates to the field of machine tool technology, wherein the method includes: driving the screw to rotate, thereby driving the turntable to rotate; obtaining the real-time rotation angle of the turntable; adjusting the length of the first drive rod and the second drive rod according to the real-time rotation angle, so that the screw maintains the same direction as the initial state; when the real-time rotation angle reaches the set rotation angle, adjusting the length of the first drive rod and the second drive rod, so that the direction of the screw deviates from the initial state. The present application connects two drive rods at the end of the screw so that the direction of the drive rod can be adjusted when the drive rod is extended and retracted, and then when the turntable rotates to the failure angle, the screw can rotate at a certain angle, thereby avoiding the failure angle, ensuring that the turntable can rotate normally at any angle without being affected by the failure angle.

Description

Technical Field

[0001] The present application relates to the field of machine tool technology, and in particular to a motor-driven turntable control method and system. Background Art

[0002] Machine tools are commonly used in mechanical processing. From traditional manual machine tools to today's fully automatic CNC machine tools, machine tool development has gone through a long process. The current three-axis or even five-axis CNC machine tools can provide very high processing accuracy, and basically do not require personnel to be on duty during the processing. They have become the preferred processing equipment for many machining centers.

[0003] During the machining process of a machine tool, the direction and position of the workpiece need to be adjusted, and at this time, the turntable needs to be driven by a motor. The traditional transmission method mainly selects a reduction box. The gears in the reduction box are driven by the high-speed rotation of the motor, and the rotation speed is reduced step by step, and finally transmitted to the turntable. Since there are a lot of contact and separation processes when the gears in the reduction box are working, the transmission accuracy of the reduction box is not high, and there is also a problem of high noise. In order to improve the accuracy of the transmission, the prior art proposes a method of converting the rotation of the motor into linear motion and then into rotation through a screw rod. For example, CN114603369A discloses a control method for a CNC machine tool turntable system, a CNC system and a computer program product. The lead screw of the patent rotates under the drive of a servo motor, and then drives the nut to move along the axis of the lead screw. The nut drives the turntable to rotate during the movement of the lead screw, thereby achieving the purpose of controlling the turntable.

[0004] However, in the above patent, the first end of the lead screw is fixed, and the second end moves with the turntable. When the center of the turntable, the first end of the lead screw and the nut are in a straight line, no matter which direction the nut moves, the turntable cannot continue to be driven to rotate, resulting in failure of control of the turntable. Summary of the invention

[0005] The embodiments of the present application provide a motor-driven turntable control method and system to solve the problem of control failure when the turntable is at a specific angle in the prior art.

[0006] On the one hand, an embodiment of the present application provides a motor-driven turntable control method, comprising:

[0007] The servo motor drives the screw to rotate, and when the screw rotates, the nut is driven to move along the axial direction of the screw, thereby driving the turntable to rotate;

[0008] During the rotation of the turntable, the real-time rotation angle of the turntable is obtained;

[0009] The lengths of the first driving rod and the second driving rod are adjusted according to the real-time rotation angle, so that the screw rod maintains the same direction as the initial state, wherein the first driving rod and the second driving rod are both telescopic structures, and one end of the first driving rod and the second driving rod are fixed, and the other end is respectively connected to the screw rod for rotation;

[0010] When the real-time rotation angle reaches the set rotation angle, the lengths of the first driving rod and the second driving rod are adjusted so that the direction of the screw rod deviates from the initial state.

[0011] On the other hand, the embodiment of the present application further provides a motor-driven turntable control system, comprising a servo motor, a screw rod, a nut, an angle sensor, a first driving rod and a second driving rod, wherein the servo motor drives the screw rod to rotate, and when the screw rod rotates, the nut is driven to move along the axial direction of the screw rod, thereby driving the turntable to rotate;

[0012] The angle sensor is arranged on the turntable, and is used to obtain the real-time rotation angle of the turntable during the rotation of the turntable;

[0013] The first driving rod and the second driving rod adjust their lengths according to the real-time rotation angle so that the screw rod maintains the same direction as the initial state, wherein the first driving rod and the second driving rod are both telescopic structures, and one end of the first driving rod and the second driving rod are fixed, and the other end is respectively connected to the screw rod for rotation;

[0014] When the real-time rotation angle reaches the set rotation angle, the first driving rod and the second driving rod adjust their lengths so that the direction of the lead screw deviates from the initial state.

[0015] A motor-driven turntable control method and system in the present application has the following advantages:

[0016] Two driving rods are connected to the end of the screw rod so that the direction of the screw rod can be adjusted when the driving rod is extended or retracted. When the turntable rotates to the failure angle, the screw rod can rotate to a certain angle to avoid the failure angle, ensuring that the turntable can rotate normally at any angle without being affected by the failure angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a motor-driven turntable control system provided in an embodiment of the present application in a first state after the turntable is applied.

[0019] Figure 2 A schematic diagram of a motor-driven turntable control system provided in an embodiment of the present application applied in a second state after the turntable is turned.

[0020] Figure 3 A schematic diagram of a motor-driven turntable control system provided in an embodiment of the present application applied to a turntable in a critical state.

[0021] Figure 4 A schematic diagram of the length adjustment structure of the drive belt provided in an embodiment of the present application.

[0022] Description of the accompanying drawings: 100, turntable; 110, core shaft; 200, screw rod; 210, nut; 220, driving belt; 300, first driving rod; 400, second driving rod; 500, servo motor; 510, first pulley; 600, second pulley; 610, adjusting rod. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] The present invention provides a motor-driven turntable control method, which includes the following steps:

[0025] S100, the servo motor 500 drives the screw rod 200 to rotate. When the screw rod 200 rotates, the screw nut 210 is driven to move along the axial direction of the screw rod 200, thereby driving the turntable 100 to rotate.

[0026] For example, the structure of the turntable control system in the embodiment of the present application is as follows: Figure 1-3 As shown, the turntable 100 is mounted on the core shaft 110 so that the turntable 100 can rotate under the drive of the screw rod 200. The outer side of the nut 210 is provided with a rotating shaft, which is rotatably plugged into the side of the turntable 100, so that the nut 210 can rotate on the side of the turntable 100, thereby matching the relative angle change of the turntable 100 and the screw rod 200.

[0027] The inner side of the nut 210 has an internal thread, and the outer side of the screw rod 200 has an external thread, and the external thread matches the internal thread. When the screw rod 200 is inserted into the nut 210, the screw rod 200 and the nut 210 form a threaded connection. When the screw rod 200 rotates under the drive of the servo motor 500, since the nut 210 is connected to the turntable 100, the nut 210 will not rotate with the screw rod 200, so that the screw rod 200 rotates inside the nut 210, and then the nut 210 moves axially on the screw rod 200. In the case that the first end of the screw rod 200 cannot move freely, the position change of the nut 210 will cause the turntable 100 to rotate, thereby achieving the effect of converting the rotation of the servo motor 500 into the rotation of the turntable 100.

[0028] S110 , obtaining a real-time rotation angle of the turntable 100 during the rotation of the turntable 100 .

[0029] Exemplarily, an angle sensor is disposed on the spindle 110 , and the angle sensor is used to obtain the real-time rotation angle of the turntable 100 .

[0030] S120, adjust the length of the first driving rod 300 and the second driving rod 400 according to the real-time rotation angle, so that the screw rod 200 maintains the same direction as the initial state, wherein the first driving rod 300 and the second driving rod 400 are both telescopic structures, and one end of the first driving rod 300 and the second driving rod 400 are fixed, and the other end is respectively rotatably connected to the screw rod 200.

[0031] Exemplarily, one end of the first driving rod 300 and the second driving rod 400 are both connected to a fixed position, such as a fixed point on a machine tool, and both driving rods can rotate at the connection. The other ends of the first driving rod 300 and the second driving rod 400 are rotatably connected to one end of an intermediate rod, so that the first driving rod 300, the second driving rod 400 and the intermediate rod can freely rotate in a plane parallel to the side of the turntable 100 at the connection point of the three, and the screw rod 200 is rotatably connected to the other end of the intermediate rod, so that the screw rod 200 can rotate in the axial direction so as to be driven by the servo motor 500 to rotate.

[0032] The first driving rod 300 and the second driving rod 400 may both be electrically driven or hydraulically driven telescopic rods, so as to be adjusted to a required length under the control of a control unit.

[0033] The initial state mentioned in this application is the state where the screw rod 200 is in a specific direction, for example Figure 1 and Figure 2 The direction of the screw rod 200, once the initial state is determined, except for the failure angle, the screw rod 200, the first drive rod 300 and the second drive rod 400 will cooperate with each other to ensure that the screw rod 200 is always in a direction parallel to the initial state.

[0034] Specifically, when the lengths of the first driving rod 300 and the second driving rod 400 are adjusted to keep the lead screw 200 in the same direction as in the initial state, the lead screw 200 is translated along the length direction of the driving belt 220 .

[0035] After adopting this control method, since the line connecting the contact positions of the drive belt 220, the first pulley 510 and the screw rod 200 in the initial state is parallel to the length direction of the drive belt 220, that is, the drive belt 220 is not skewed, after ensuring that the screw rod 200 is always in a direction parallel to the initial state, the drive belt 220 will not be skewed, thereby avoiding the drive belt 220 from being skewed due to a large change in the direction of the screw rod 200, thereby preventing the drive belt 220 from loosening.

[0036] Furthermore, in addition to the failure angle, in the normal control process, the real-time rotation angle of the turntable 100 and the moving distance of the nut 210 satisfy the following formula:

[0037]

[0038] Wherein, L represents the moving distance of the nut 210, R represents the distance between the center of the nut 210 and the center of the turntable 100, and α represents the real-time rotation angle of the turntable 100;

[0039] The moving distance L and the number of revolutions of the servo motor 500 are determined by the following formula:

[0040] L = acd

[0041] Wherein, a represents the ratio of the diameter of the screw rod 200 to the diameter of the first pulley 510 driven by the servo motor 500 , c represents the number of rotations of the servo motor 500 , and d represents the pitch of the screw rod 200 .

[0042] After determining the above relationship, once the angle at which the turntable 100 needs to rotate is determined, the number of revolutions that the servo motor 500 needs to rotate can be obtained, and then the control unit controls the servo motor 500 to rotate the required number of revolutions to rotate the turntable 100 to the required angle.

[0043] It should be understood that the movement of the nut 210 on the screw rod 200 is a reciprocating motion, that is, after moving to one end under the drive of the screw rod 200, the screw rod 200 will reverse to make the nut 210 move in the opposite direction, and this cycle will be repeated to achieve the effect of continuous rotation control of the turntable 100.

[0044] S130, when the real-time rotation angle reaches the set rotation angle, the lengths of the first driving rod 300 and the second driving rod 400 are adjusted to make the direction of the screw rod 200 deviate from the initial state.

[0045] Exemplarily, the rotation angle is set to a certain angle before the first end of the screw rod 200, the nut 210 and the center of the turntable 100 are in a straight line. The above failure angle is the angle of the turntable 100 when the direction of the screw rod 200 is not adjusted, the first end of the screw rod 200, the nut 210 and the center of the turntable 100 are in a straight line. At this time, the three points are in a straight line. If the turntable 100 happens to stop at this time, and when it continues to rotate, due to the absence of inertia, the turntable 100 cannot pass the failure angle. No matter in which direction the nut 210 rotates on the screw rod 200, the force applied by the nut 210 on the turntable 100 will be in a straight line connected by the three points, causing the turntable 100 to be unable to continue to rotate under the action of this force. In order to avoid this situation, the present application controls the two driving rods to have a small change in length when the turntable is about to rotate to the failure angle, that is, a set rotation angle at a certain angle before the failure angle, so that there is a small angle between the screw rod 200 and the direction of the initial state, such as 1°, 0.5° or even a smaller angle greater than zero. At this time, the screw rod 200 can be made to deviate from the original failure angle, thereby avoiding the situation where the turntable 100 cannot be rotated.

[0046] Furthermore, the first driving rod 300 and the second driving rod 400 begin to adjust their lengths before the turntable 100 rotates to the failure angle, and when the turntable 100 rotates to the failure angle, the first driving rod 300 and the second driving rod 400 also complete the adjustment of their lengths.

[0047] Specifically, since it takes a certain amount of time to adjust the length of the two driving rods, the embodiment of the present application will immediately control the two driving rods to adjust their lengths after the turntable 100 rotates to the set rotation angle, and then when the turntable 100 reaches the failure angle, the length adjustment operation of the driving rods is also completed.

[0048] The embodiment of the present application further provides a motor-driven turntable control system, which includes a servo motor 500, a screw rod 200, a nut 210, an angle sensor, a first driving rod 300 and a second driving rod 400. The servo motor 500 drives the screw rod 200 to rotate, and when the screw rod 200 rotates, the nut 210 is driven to move along the axial direction of the screw rod 200, thereby driving the turntable 100 to rotate.

[0049] The angle sensor is disposed on the turntable 100 and is used to obtain the real-time rotation angle of the turntable 100 during the rotation of the turntable 100;

[0050] The first driving rod 300 and the second driving rod 400 adjust their lengths according to the real-time rotation angle, so that the screw rod 200 maintains the same direction as the initial state, wherein the first driving rod 300 and the second driving rod 400 are both telescopic structures, and one end of the first driving rod 300 and the second driving rod 400 are fixed, and the other end is respectively rotatably connected to the screw rod 200;

[0051] When the real-time rotation angle reaches the set rotation angle, the first driving rod 300 and the second driving rod 400 adjust their lengths so that the direction of the screw rod 200 deviates from the initial state.

[0052] For example, since the screw rod 200 will translate under the control of the two driving rods, the distance between the screw rod 200 and the first pulley 510 will change. In order to prevent the driving belt 220 from being unable to stably contact the screw rod 200 after the position of the screw rod 200 changes, the embodiment of the present application also provides a second pulley 600 on the inner side of the driving belt 220, and the second pulley 600 is rotatably connected to the adjusting rod 610, and the adjusting rod 610 can rotate in a direction perpendicular to the length direction.

[0053] The inner side of the driving belt 220 contacts the second pulley 600, and the servo motor 500 drives the first pulley 510 to rotate. The driving belt 220 is sleeved on the outer side of the first pulley 510 and the screw rod 200. The adjusting rod 610 will maintain a tendency to rotate toward the outside of the driving belt 220 under the action of the torsion spring. Under this tendency, the second pulley 600 will always apply outward tension to the driving belt 220, and thus no matter what position the screw rod 200 is in, the driving belt 220 will be in stable contact with the screw rod 200 under the action of tension, ensuring that the drive of the servo motor 500 is always effective. Figure 4 shown.

[0054] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A motor-driven turntable control method, characterized in that: include: The screw rod (200) is driven to rotate by a servo motor (500), and when the screw rod (200) rotates, the screw nut (210) is driven to move along the axial direction of the screw rod (200), thereby driving the turntable (100) to rotate; During the rotation of the turntable (100), obtaining a real-time rotation angle of the turntable (100); The lengths of the first driving rod (300) and the second driving rod (400) are adjusted according to the real-time rotation angle, so that the screw rod (200) maintains the same direction as the initial state, wherein the first driving rod (300) and the second driving rod (400) are both telescopic structures, and one end of the first driving rod (300) and the second driving rod (400) are fixed, and the other end is respectively rotatably connected to the screw rod (200); When the real-time rotation angle reaches the set rotation angle, the lengths of the first driving rod (300) and the second driving rod (400) are adjusted so that the direction of the screw rod (200) deviates from the initial state.

2. A motor-driven turntable control method according to claim 1, characterized in that: The real-time rotation angle of the turntable (100) and the moving distance of the nut (210) satisfy the following formula: Wherein, L represents the moving distance of the nut (210), R represents the distance between the center of the nut (210) and the center of the turntable (100), and α represents the real-time rotation angle of the turntable (100); The moving distance L and the number of rotations of the servo motor (500) are determined by the following formula: L = acd Wherein, a represents the ratio of the diameter of the screw rod (200) to the diameter of the first pulley (510) driven by the servo motor (500), c represents the number of rotations of the servo motor (500), and d represents the pitch of the screw rod (200).

3. The motor-driven turntable control method according to claim 1, characterized in that: The real-time rotation angle of the turntable (100) is acquired by an angle sensor arranged on the core shaft (110) of the turntable (100).

4. The motor-driven turntable control method according to claim 1, characterized in that: When the lengths of the first driving rod (300) and the second driving rod (400) are adjusted so that the screw rod (200) maintains the same direction as in the initial state, the screw rod (200) is translated along the length direction of the driving belt (220).

5. The motor-driven turntable control method according to claim 1, characterized in that: The set rotation angle is a certain angle between the first end of the screw rod (200), the nut (210) and the center of the turntable (100) in front of a straight line.

6. A motor-driven turntable control method according to claim 5, characterized in that: The first driving rod (300) and the second driving rod (400) begin to adjust their lengths before the turntable (100) rotates to the failure angle, and when the turntable (100) rotates to the failure angle, the first driving rod (300) and the second driving rod (400) also complete the length adjustment.

7. A motor-driven turntable control system, the system applying the method according to any one of claims 1 to 6, characterized in that: The invention comprises a servo motor (500), a screw rod (200), a nut (210), an angle sensor, a first driving rod (300) and a second driving rod (400), wherein the servo motor (500) drives the screw rod (200) to rotate, and when the screw rod (200) rotates, the nut (210) is driven to move along the axial direction of the screw rod (200), thereby driving the turntable (100) to rotate; The angle sensor is arranged on the turntable (100) and is used to obtain the real-time rotation angle of the turntable (100) during the rotation of the turntable (100); The first driving rod (300) and the second driving rod (400) adjust their lengths according to the real-time rotation angle so that the screw rod (200) maintains the same direction as in the initial state, wherein the first driving rod (300) and the second driving rod (400) are both telescopic structures, and one end of the first driving rod (300) and the second driving rod (400) are fixed, and the other end is respectively rotatably connected to the screw rod (200); When the real-time rotation angle reaches the set rotation angle, the first driving rod (300) and the second driving rod (400) adjust their lengths so that the direction of the screw rod (200) deviates from the initial state.

8. A motor-driven turntable control system according to claim 7, characterized in that: include: The end of the first driving rod (300) and the end of the second driving rod (400) are both rotatably connected to one end of the intermediate rod, and the other end of the intermediate rod is rotatably connected to the screw rod (200) around the axial direction.

9. The motor-driven turntable control system according to claim 7, characterized in that: The servo motor (500) drives the first pulley (510) to rotate. A driving belt (220) is sleeved on the outer side of the first pulley (510) and the screw rod (200). The inner side of the driving belt (220) is also in contact with the second pulley (600). The second pulley (600) is rotatably connected to the adjusting rod (610). The adjusting rod (610) can rotate in a direction perpendicular to the length direction.

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