Low-damage high-precision physical positioning zero adjustment device and method thereof

Abstract

The application belongs to the field of high-precision positioning devices, and discloses a low-damage high-precision physical positioning zero adjustment device and a method thereof. The device comprises a base, a lead screw, a lead screw nut, a motor, a nut transition block, an elastic body, a sensor and a zero adjustment working component. The nut transition block is connected to the lead screw nut through sliding in the up-down direction, and the two do not rotate relative to each other in the circumferential direction. The elastic body presses or pulls the nut transition block downward, so that the lower end of the nut transition block is blocked with the lead screw nut. The sensor is a distance sensor or a force sensor. The distance sensor detects the sliding separation distance of the lead screw nut relative to the nut transition block, and the force sensor detects the force of the elastic body. The zero adjustment working component comprises a movable lifting part and a fixed calibration part. The movable lifting part is connected to the nut transition block, and the fixed calibration part is fixedly arranged at the lower end of the movable lifting part. The application greatly widens the application range of physical zero adjustment, prolongs the service life of related components, and reduces the production cost.

Description

Technical Field

[0001] This invention relates to the field of high-precision positioning devices, specifically a low-damage, high-precision physical positioning zeroing device and method. Background Technology

[0002] In traditional lead screw driven axial motion systems, the initial position of the lead screw is determined by the following method: the motor drives the lead screw to move, so that the parts directly or indirectly connected to the lead screw nut and the parts fixed on the base (i.e., two parts with relative movement) come into contact with each other, and the position of the motor encoder (or other measuring sensors) at this time is recorded. This position is used as the initial zero position of the drive system.

[0003] However, at the instant the two relatively moving parts come into contact, the motor still has a driving torque. This torque, when converted into the axial force of the lead screw, is often very large, which can cause the following problems:

[0004] 1) Components that are directly or indirectly connected between the lead screw assembly and these two relatively moving parts may be damaged or plastically deformed if they have low tensile or compressive strength due to large forces.

[0005] 2) If there are slender parts in the components that are directly or indirectly connected between the lead screw assembly and these two relatively moving parts, they may become unstable and deform due to large forces, affecting the linear accuracy of the drive system. Summary of the Invention

[0006] The purpose of this invention is to provide a low-damage, high-precision physical positioning and zeroing device and method to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A low-damage, high-precision physical positioning zeroing device includes a base, a lead screw vertically rotatably mounted on the base, a lead screw nut screwed onto the lead screw, and a motor driving the lead screw to rotate. The motor is equipped with an encoder. The device also includes a nut transition block, an elastic body, a sensor, and a zeroing working component. The nut transition block is slidably connected to the lead screw nut without circumferential relative rotation. The elastic body presses or pulls the nut transition block downwards, causing it to engage with the lead screw nut. The sensor is either a distance sensor or a force sensor. The distance sensor detects the sliding distance of the lead screw nut relative to the nut transition block, and the force sensor detects the force exerted by the elastic body. The zeroing working component includes a movable lifting part and a fixed calibration part. The movable lifting part is connected to the nut transition block and moves up and down with it. The fixed calibration part is fixedly located at the lower end of the movable lifting part. When the low-damage, high-precision physical positioning zeroing device is in the zeroing detection state, the movable lifting part abuts against the fixed calibration part.

[0009] Furthermore, the elastomer is a compression spring, a damping rod, or an organic polymer elastomer.

[0010] Furthermore, it also includes a clamping nut screwed onto the lead screw, wherein the clamping nut, sensor, elastomer and nut transition block are arranged sequentially from top to bottom, and the clamping nut pre-tightens the elastomer.

[0011] Furthermore, one of the nut transition block and the lead screw nut is provided with a slot, and the other is provided with a vertically mounted pin that slides and engages with the slot.

[0012] Furthermore, the motor is either a servo motor with a built-in encoder or a stepper motor with an external encoder.

[0013] Furthermore, the movable lifting part includes a lifting worktable connected to the nut transition block and a zeroing working rod disposed on the lifting worktable, the zeroing working rod being used to abut against the fixed calibration part.

[0014] Furthermore, the zero-adjustment working rod is vertically rotatably mounted on the lifting work platform, and its rotation is driven by a driver.

[0015] Furthermore, it also includes a guide mechanism, through which the movable lifting part slides up and down on the base.

[0016] The present invention also provides a zeroing method for a low-damage, high-precision physical positioning zeroing device, comprising:

[0017] Step 1: Adjust the preload of the elastomer to an appropriate value by tightening the nut, and read the value F0 from the force sensor;

[0018] Step 2: Control the motor to bring the movable lifting part closer to the fixed calibration part until the two are in close contact. Continue to run the motor for a period of time and then stop. Read the force sensor value F1 and the first encoder position S1 of the motor at this time.

[0019] Step 3: Calculate the position of the second encoder when the low-damage high-precision physical positioning zeroing device is at zero position: S0 = S1 - (F1 - F0) / K, where K is the elastic stiffness of the elastic body.

[0020] The present invention also provides a zeroing method for a low-damage, high-precision physical positioning zeroing device, comprising:

[0021] Step 1: Adjust the preload of the elastomer to an appropriate value by tightening the nut;

[0022] Step 2: Control the motor to bring the movable lifting part closer to the fixed calibration part until the two are in close contact. Continue to run the motor for a period of time and then stop. Read the distance sensor value d and the first encoder position S1 of the motor at this time.

[0023] Step 3: Calculate the position of the second encoder S0 = S1 - d when the low-damage, high-precision physical positioning zeroing device is at zero position.

[0024] Compared with the prior art, the beneficial effects of the present invention are: the present invention greatly expands the application scope of physical zeroing, extends the service life of related components, reduces production costs, and makes material selection and structural design easier to achieve when designing drive systems. Attached Figure Description

[0025] Figure 1 This is one of the structural schematic diagrams of Example 1.

[0026] Figure 2 This is the second schematic diagram of the structure of Example 1.

[0027] Figure 3 for Figure 2 Sectional view of AA.

[0028] Figure 4 This is a flowchart of Example 3.

[0029] Figure 5 This is a flowchart of Example 4.

[0030] In the diagram: 1. Base; 2. Lead screw; 3. Lead screw nut; 4. Motor; 5. Nut transition block; 6. Compression spring; 7. Sensor; 8. Fixed calibration unit; 9. Lifting worktable; 10. Zero adjustment rod; 11. Clamping nut; 12. Pin hole; 13. Pin shaft; 14. Guide rail; 15. Slider; 16. Motor transition seat; 17. Coupling; 18. Bearing seat assembly. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] Please see Figures 1-3A low-damage, high-precision physical positioning zeroing device includes a base 1, a lead screw 2, a lead screw nut 3, a motor 4, a nut transition block 5, an elastic body, a sensor 7, a motor transition seat 16, and zeroing working components. The lead screw 2 is vertically rotatably mounted on the base 1 via a bearing housing assembly 18. The lead screw nut 3 is screwed onto the lead screw 2. The motor transition seat 16 is fixedly mounted on the lower end of the base 1, and the motor 4 is fixedly mounted on the lower end of the motor transition seat 16. The motor 4 and the lead screw 2 are connected via a coupling 17, which is located inside the motor transition seat 16. The motor 4 drives the lead screw 2 to rotate. The motor 4 is preferably a servo motor with a built-in encoder, but other types can also be used. The stepper motor uses an external encoder. The nut transition block 5 is slidably connected to the lead screw nut 3. The two do not rotate relative to each other in the circumference. The elastic body presses or pulls the nut transition block 5 down, so that the lower end of the nut transition block 5 is in contact with the lead screw nut 3. The sensor 7 is a force sensor. The zeroing working part includes a movable lifting part and a fixed calibration part 8. The movable lifting part is connected to the nut transition block 5 and moves up and down with the nut transition block 5. The fixed calibration part 8 is fixedly connected to the lower end of the base 1 and is located at the lower end of the movable lifting part. When the low-damage high-precision physical positioning zeroing device is in the zeroing detection state, the movable lifting part and the fixed calibration part 8 abut against each other.

[0034] Continue reading Figures 1-3 The elastomer is preferably a compression spring 6 sleeved on the lead screw nut 3, which presses the nut transition block 5 downward. In other embodiments, the elastomer can also be a tension spring, which pulls the nut transition block 5 downward. In other embodiments, the elastomer can also be a damping rod or an organic polymer elastomer.

[0035] Continue reading Figures 1-3 The low-damage, high-precision physical positioning zeroing device also includes a clamping nut 11 screwed onto the lead screw 2. The clamping nut 11, sensor 7, elastic body, and nut transition block 5 are arranged sequentially from top to bottom. The clamping nut 11 pre-tightens the elastic body. The sensor 7 is sleeved on the lead screw 2 and detects the force of the compression spring 6. The nut transition block 5 is sleeved on the lead screw nut 3.

[0036] Continue reading Figure 3 The bottom of the nut transition block 5 is vertically provided with a pin hole 12, and a pin shaft 13 is installed on the pin hole 12. The boss at the lower end of the lead screw nut 3 is vertically provided with a groove that slides up and down with the pin shaft 13 to prevent rotational movement between the lead screw nut 3 and the nut transition block 5, allowing only axial movement between the two.

[0037] The fit structure between the lead screw nut 3 and the nut transition block 5 can be different, as long as the fit structure allows only axial movement between the two. For example, the two can fit together in the form of a keyway.

[0038] Continue reading Figures 1-3The movable lifting unit includes a lifting worktable 9 connected to a nut transition block 5 and a zero-adjustment working rod 10 disposed on the lifting worktable 9. The zero-adjustment working rod 10 and the fixed calibration unit 8 can be controlled by a motor 4 to perform vertical relative movement. The zero-adjustment working rod 10 is used to abut against the fixed calibration unit 8. The zero-adjustment working rod 10 is vertically rotatably mounted on the lifting worktable 9. The lifting worktable 9 and the zero-adjustment working rod 10 are separately disposed, but they can also be integrated. In some embodiments, the zero-adjustment working rod 10 is fixed to the lifting worktable 8 by bearings, and the zero-adjustment working rod 10 can be connected to a driver to achieve rotation; the driver is a motor.

[0039] Continue reading Figures 1-3 It also includes a guide mechanism, through which the movable lifting part slides up and down on the base 1. The guide mechanism can have multiple different forms and types, one of the preferred solutions being a linear guide rail assembly. The linear guide rail assembly includes a guide rail 14 laid vertically on the base 1 and a slider 15 that slides up and down on the guide rail 14. The slider 15 can resist a certain bending moment and is connected to the lifting worktable 9.

[0040] Example 2

[0041] The difference between this embodiment and embodiment 1 is that the sensor 7 in this embodiment is a distance sensor, which detects the sliding disengagement distance of the lead screw nut 3 relative to the nut transition block 5.

[0042] Example 3

[0043] Please see Figure 4 A zeroing method for a low-damage, high-precision physical positioning zeroing device as described in Example 1, comprising:

[0044] Step 1: Adjust the preload of the compression spring 6 to an appropriate value by tightening the nut 11 (in principle, it should not damage the parts in the device or cause deformation error that has a significant impact on the device, and there should still be enough spring compression). Compress the spring 6 so that the lower end of the nut transition block 5 abuts against the lead screw nut 3, and read the value F0 in the force sensor.

[0045] Step two: Control motor 4 to operate. Motor 4 drives screw nut 3, along with nut transition block 5 and movable lifting part, to move downwards via lead screw 2, bringing zeroing rod 10 close to fixed calibration part 8 until they are in contact. Continue running motor 4 for 1-2 seconds and then stop. During these 1-2 seconds, lead screw nut 3 continues to move downwards, while nut transition block 5 cannot move further due to the restraint of movable lifting part. Thus, lead screw nut 3 disengages from nut transition block 5 by a certain distance. At this time, read the force sensor value F1 and the servo motor encoder position S1 after motor 4 stops. Furthermore, at this time, the pressure on zeroing rod 10 and fixed calibration part 8 is the actual force of compression spring 6. This force is much smaller than the driving force of servo motor and will not damage the device components or cause significant errors.

[0046] Step 3: Calculate the servo motor encoder position S0 when the zeroing device is at zero position: S0 = S1 - (F1 - F0) / K, where K is the elastic stiffness of the compression spring.

[0047] It should be noted that "zero position" refers to the encoder position S0 of the drive motor at the moment when the zeroing working rod 10 is in contact with the lifting worktable 8. The process from step one to step three is to obtain the value of S0.

[0048] Example 4

[0049] Please see Figure 5 A zeroing method for a low-damage, high-precision physical positioning zeroing device as described in Example 2, comprising:

[0050] Step 1: Adjust the preload of the elastomer to an appropriate value by tightening nut 11;

[0051] Step 2: Control the motor 4 to work. The motor 4 drives the lead screw nut 3, along with the nut transition block 5 and the movable lifting part, to move down through the lead screw 2, so that the zeroing working rod 10 is close to the fixed calibration part 8 until the two are in close contact. Continue to run the motor 4 for 1 to 2 seconds and then stop. During these 1 to 2 seconds, the lead screw nut 3 continues to move down. The nut transition block 5 cannot move down further due to the restraint of the movable lifting part. Thus, the lead screw nut 3 disengages from the nut transition block 5 by a certain distance. At this time, read the distance sensor value d after the motor 4 stops and the first encoder position S1 of the motor 4.

[0052] Step 3: Calculate the position of the second encoder S0 = S1 - d when the low-damage, high-precision physical positioning zeroing device is at zero position.

[0053] It should be noted that in Embodiment 3, the force sensor is ultimately used to read the disengagement distance between the lead screw nut 3 and the nut transition block 5. In this embodiment, a distance sensor is used instead of a force sensor to directly measure and read the disengagement distance d between the lead screw nut 3 and the nut transition block 5. Therefore, when the zeroing device is at zero position, the servo motor encoder position S0 = S1 - d.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A zeroing method for a low-damage, high-precision physical positioning zeroing device, characterized in that, The low-damage, high-precision physical positioning zeroing device includes a base (1), a lead screw (2) vertically rotatably mounted on the base (1), a lead screw nut (3) screwed onto the lead screw (2), a motor (4) driving the lead screw (2) to rotate, a nut transition block (5), an elastic body, a sensor (7), a zeroing working component, and a clamping nut (11) screwed onto the lead screw (2). The motor (4) is equipped with an encoder. The nut transition block (5) slides up and down on the lead screw nut (3) without circumferential relative rotation. The elastic body presses or pulls the nut transition block (5) down, so that the nut transition block (5) and the lead screw nut (3) are in contact. The sensor (7) is a distance sensor or a force sensor. The device includes a distance sensor that detects the sliding disengagement distance of the lead screw nut (3) relative to the nut transition block (5), a force sensor that detects the force of the elastic body, and a zeroing working component that includes a movable lifting part and a fixed calibration part (8). The movable lifting part is connected to the nut transition block (5) and moves up and down together with the nut transition block (5). The fixed calibration part (8) is fixedly set and located at the lower end of the movable lifting part. When the low-damage high-precision physical positioning zeroing device is in the zeroing detection state, the movable lifting part abuts against the fixed calibration part (8). The clamping nut (11), sensor (7), elastic body and nut transition block (5) are arranged in sequence from top to bottom. The clamping nut (11) pre-tightens the elastic body. The movable lifting part includes a lifting worktable (9) connected to the nut transition block (5) and a zero-adjustment working rod (10) provided on the lifting worktable (9), the zero-adjustment working rod (10) being used to abut against the fixed calibration part (8); The zero-adjustment working rod (10) is vertically rotatably mounted on the lifting worktable (9), and it is driven to rotate by a driver. Zeroing methods include: Step 1: Adjust the preload of the elastomer to an appropriate value by tightening the nut (11) and read the value F0 from the force sensor; Step 2: Control the motor (4) to bring the movable lifting part close to the fixed calibration part (8) until the two are in close contact. Continue to run the motor (4) for a period of time and then stop. Read the force sensor value F1 and the first encoder position S1 of the motor (4) at this time. Step 3: Calculate the position of the second encoder when the low-damage high-precision physical positioning zeroing device is at zero position: S0 = S1 - (F1 - F0) / K, where K is the elastic stiffness of the elastic body.

2. The zeroing method of the low-damage, high-precision physical positioning zeroing device according to claim 1, characterized in that, The elastomer is a compression spring (6), a damping rod, or an organic polymer elastomer.

3. The zeroing method of the low-damage, high-precision physical positioning zeroing device according to claim 1, characterized in that, The nut transition block (5) and the lead screw nut (3) are provided with a slot, and the other is provided with a pin (13) that slides up and down with the slot.

4. The zeroing method of the low-damage, high-precision physical positioning zeroing device according to claim 1, characterized in that, The motor (4) is either a servo motor with its own encoder or a stepper motor with an external encoder.

5. The zeroing method of a low-damage, high-precision physical positioning zeroing device according to claim 1, characterized in that, The low-damage, high-precision physical positioning zeroing device also includes a guide mechanism, and the movable lifting part slides up and down on the base (1) through the guide mechanism.

6. A zeroing method for a low-damage, high-precision physical positioning zeroing device, characterized in that, The low-damage, high-precision physical positioning zeroing device includes a base (1), a lead screw (2) vertically rotatably mounted on the base (1), a lead screw nut (3) screwed onto the lead screw (2), a motor (4) driving the lead screw (2) to rotate, a nut transition block (5), an elastic body, a sensor (7), a zeroing working component, and a clamping nut (11) screwed onto the lead screw (2). The motor (4) is equipped with an encoder. The nut transition block (5) slides up and down on the lead screw nut (3) without circumferential relative rotation. The elastic body presses or pulls the nut transition block (5) down, so that the nut transition block (5) and the lead screw nut (3) are in contact. The sensor (7) is a distance sensor or a force sensor. The device includes a distance sensor that detects the sliding disengagement distance of the lead screw nut (3) relative to the nut transition block (5), a force sensor that detects the force of the elastic body, and a zeroing working component that includes a movable lifting part and a fixed calibration part (8). The movable lifting part is connected to the nut transition block (5) and moves up and down together with the nut transition block (5). The fixed calibration part (8) is fixedly set and located at the lower end of the movable lifting part. When the low-damage high-precision physical positioning zeroing device is in the zeroing detection state, the movable lifting part abuts against the fixed calibration part (8). The clamping nut (11), sensor (7), elastic body and nut transition block (5) are arranged in sequence from top to bottom. The clamping nut (11) pre-tightens the elastic body. The movable lifting part includes a lifting worktable (9) connected to the nut transition block (5) and a zero-adjustment working rod (10) provided on the lifting worktable (9), the zero-adjustment working rod (10) being used to abut against the fixed calibration part (8); The zero-adjustment working rod (10) is vertically rotatably mounted on the lifting worktable (9), and it is driven to rotate by a driver. Zeroing methods include: Step 1: Adjust the preload of the elastomer to an appropriate value by tightening the nut (11); Step 2: Control the motor (4) to bring the movable lifting part close to the fixed calibration part (8) until the two are in close contact. Continue to run the motor (4) for a certain period of time and then stop. Read the distance sensor value d and the first encoder position S1 of the motor (4) at this time. Step 3: Calculate the position of the second encoder S0=S1-d when the low-damage high-precision physical positioning zeroing device is at zero position.

7. The zeroing method of a low-damage, high-precision physical positioning zeroing device according to claim 6, characterized in that, The elastomer is a compression spring (6), a damping rod, or an organic polymer elastomer.

8. The zeroing method of a low-damage, high-precision physical positioning zeroing device according to claim 6, characterized in that, The nut transition block (5) and the lead screw nut (3) are provided with a slot, and the other is provided with a pin (13) that slides up and down with the slot.

9. The zeroing method of a low-damage, high-precision physical positioning zeroing device according to claim 6, characterized in that, The motor (4) is either a servo motor with its own encoder or a stepper motor with an external encoder.

10. The zeroing method of a low-damage, high-precision physical positioning zeroing device according to claim 6, characterized in that, The low-damage, high-precision physical positioning zeroing device also includes a guide mechanism, and the movable lifting part slides up and down on the base (1) through the guide mechanism.

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