A programmable servo torque tailstock

Abstract

The present invention relates to the technical field of servo torque tailstocks, and particularly to a programmable servo torque tailstock, comprising: a clamping mechanism, including a tailstock body, a tightening assembly for clamping a workpiece by docking with a top groove of the workpiece, a first controller for adjusting the starting clamping mode of the workpiece operation according to the change amount of the horizontal length of the cavity in the tailstock body, a tailstock carriage, the tightening assembly including a rotating bushing, a center for transmitting a tightening torque to the workpiece, and a locking element; a moving mechanism for conveying the clamping mechanism to a target working position, including a bed guide rail, a servo motor, and a second controller for determining the moving mode of the tailstock body according to the translation distance difference of the center and adjusting the entry mode of the center into the top groove according to the fluctuation value of the load equivalent of the servo motor; a detection mechanism, including a first laser rangefinder and a second laser rangefinder. The present invention realizes the improvement of the working stability of the tailstock and the accuracy of clamping the workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of servo torque tailstocks, and in particular to a programmable servo torque tailstock. Background Art

[0002] In the prior art, a programmed servo tailstock uses a control system to monitor and control the movement of a motor. The control system usually consists of a controller and an encoder. The encoder is used to measure the position and speed of the motor, and the controller controls the movement of the motor according to a pre-set program; the programmable servo tailstock can achieve various motion control modes, such as position control, speed control, and force control. By adjusting the parameters and settings of the controller, different motion requirements can be achieved, so as to adapt to different application scenarios; the programmable servo tailstock has high precision and repeatability. By using an encoder and a closed-loop control system, precise control of the motor position can be achieved, thus realizing high-precision motion.

[0003] Chinese Patent Application Publication No.: CN114433891A discloses a servo tailstock of a machine tool, including a tailstock body and a tailstock saddle. The tailstock body is provided with a center drill. It is characterized in that a positioning groove is provided at the bottom of the tailstock body. The positioning groove has two relatively arranged groove walls that are both perpendicular to the axis of the center drill. A cylindrical pin extending between the two groove walls is provided on the tailstock saddle. The diameter of the cylindrical pin is the same as the distance between the two groove walls. An adjusting device capable of pushing the tailstock body to make the cylindrical pin slide along the two opposite groove walls or make the tailstock body swing around the cylindrical pin is provided on the tailstock saddle. Thus, the servo tailstock of the machine tool has problems such as the workpiece not being able to maintain a horizontal position before positioning due to the excessive length and weight of the workpiece, resulting in inaccurate clamping by the center drill, the positioning function of the tailstock being unstable when the machine tool processes the workpiece due to impurities in the top groove, the clamping preloading force having an error due to the fatigue of the center drill, and the tailstock offset caused by the torque fluctuation at the contact surface between the center drill and the top groove due to the rotation eccentricity of the workpiece. Summary of the Invention

[0004] Therefore, the present invention provides a programmable servo torque tailstock to overcome the problems in the prior art that the workpiece cannot maintain a horizontal position before positioning due to the excessive length and weight of the workpiece, resulting in inaccurate clamping by the center drill, the positioning function of the tailstock being unstable when the machine tool processes the workpiece due to impurities in the top groove, the clamping preloading force having an error due to the fatigue of the center drill, and the tailstock offset caused by the torque fluctuation at the contact surface between the center drill and the top groove due to the rotation eccentricity of the workpiece.

[0005] To achieve the above object, the present invention provides a programmable servo torque tailstock, comprising:

[0006] 1. A programmable servo torque tailstock, characterized in that it includes:

[0007] A clamping mechanism, including a tailstock body for supporting a workpiece, a tightening assembly connected to the tailstock body for clamping the workpiece, a tailstock support plate arranged below the tailstock body for driving the tailstock body to move parallel to a target working position, and a first controller connected to the tightening assembly for adjusting the initial clamping mode of the workpiece operation according to the change in the horizontal length of the cavity in the tailstock body.

[0008] Wherein, the tightening assembly includes a rotating shaft sleeve connected to the tailstock body, a center point connected to the rotating shaft sleeve for transmitting a tightening torque to the top groove of the workpiece, and a locking element arranged inside the rotating shaft sleeve for locking the rotating shaft sleeve.

[0009] A moving mechanism, connected to the clamping mechanism for transporting the clamping mechanism to a corresponding position, including a bed guide rail passing through the tailstock support plate for determining the moving direction of the tailstock support plate, a servo motor connected to the bed guide rail for providing a rotational driving force for the bed guide rail, and a second controller connected to the servo motor for determining the moving mode of the tailstock body according to the translation distance difference of the center point, and adjusting the entry mode of the center point into the top groove according to the fluctuation value of the load equivalent of the motor shaft.

[0010] A detection mechanism, connected to the clamping mechanism, including a first laser rangefinder arranged above the tailstock body for detecting the horizontal distance between the center point and the inner wall of the top groove, and a second laser rangefinder for detecting the horizontal length of the cavity in the tailstock body.

[0011] Further, the second controller is connected to the servo motor for obtaining the load equivalent of the motor shaft when the servo motor operates. If the load equivalent is greater than or equal to the no-load load equivalent, it is determined that the tightening assembly contacts the inner wall of the top groove.

[0012] Further, the second controller is respectively connected to the servo motor and the first laser rangefinder for respectively obtaining the translation distance of the tightening assembly when contacting the inner wall of the top groove and the theoretical distance between the tightening assembly and the inner wall of the top groove, and calculating the translation distance difference. According to the comparison result that the translation distance difference is greater than or equal to a preset first translation distance difference, it is determined that the docking accuracy does not meet the requirements, and according to the translation distance difference being greater than or equal to a preset second translation distance difference, the output torque of the servo motor is controlled to operate according to an S-shaped acceleration curve.

[0013] Further, the acceleration change rate at the high inflection point of the S-shaped acceleration curve is positively correlated with the translation distance difference; the translation distance difference is the difference between the theoretical distance and the translation distance, and the preset first translation distance difference is less than the preset second translation distance difference.

[0014] Among them, the S-shaped acceleration curve is the curve of the acceleration of the output torque changing with time.

[0015] Further, the second controller is respectively connected to the servo motor and the first laser rangefinder, and is used for preliminarily determining that the loading stability does not meet the requirements under the condition that the translation distance difference is greater than or equal to a preset first translation distance difference and less than a preset second translation distance difference, and obtaining the load equivalent after determining that the pressing component contacts the inner wall of the top groove to calculate the fluctuation value of the load equivalent;

[0016] According to the fact that the fluctuation value is greater than or equal to a preset second fluctuation value, it is determined for the second time that the loading stability does not meet the requirements, and a stability loading action is executed as the entry method for the pressing component to enter the top groove.

[0017] Further, the fluctuation value of the load equivalent is the difference between the maximum value and the minimum value of the load equivalent within the loading duration; the preset first fluctuation value is less than the preset second fluctuation value.

[0018] Further, the stability loading action is that the servo motor controls the tailstock body to approach the top groove at a preset speed to a preset distance and then retreats reversely out of the top groove, and the stability loading action is repeated at least once.

[0019] Further, the first controller is respectively connected to the pressing component and the second laser rangefinder, and is used for preliminarily determining that the tip stability does not meet the requirements under the condition that the fluctuation value of the load equivalent is greater than or equal to a preset first fluctuation value and less than a preset second fluctuation value, and calculating the horizontal length change amount according to the horizontal length of the cavity in the tailstock body,

[0020] According to the fact that the horizontal length change amount is greater than or equal to a preset length change amount, it is determined for the second time that the tip stability does not meet the requirements, and the pressing component is controlled to adopt a movable starting clamping method.

[0021] Further, the horizontal length change amount is the difference between the horizontal length of the cavity under the condition that the load equivalent is equal to the no-load load equivalent and the horizontal length of the cavity under the condition that the load equivalent is equal to a preset pre-tightening force;

[0022] The movable starting clamping method is that the pressing component applies a pressing force compensation to the tip fixing force during the process of rotating and following the workpiece and then locks the rotating shaft sleeve.

[0023] Further, a ball screw is arranged inside the tailstock support plate, and the ball screw is slidably connected to the guide rail.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows. By setting a clamping mechanism, a moving mechanism and a detection mechanism in the device of the present invention, since the workpiece is too long and heavy, the workpiece cannot be kept horizontal before positioning, resulting in inaccurate clamping by the center point. The detection mechanism monitors the deviation between the translation distance of the tightening component and the theoretical value in real time. The servo motor adjusts the acceleration curve of the movement of the tailstock body based on the dynamic translation distance difference, and adopts a flexible motion control strategy, which can actively compensate for the deflection deformation caused by the self-weight of the workpiece, ensuring that the ultra-long and overweight workpiece always maintains a horizontal posture during the positioning process; due to the presence of impurities in the top groove, the positioning function of the tailstock is unstable when the machine tool processes the workpiece. Due to the interference of foreign matters such as metal chips and coolant residues in the top groove of the workpiece, the recognition effect of the load equivalent of the pre-tightening force of the servo motor is affected. By adjusting the entry method and using the entry of the center point to reduce the impurities remaining in the top groove, the working stability of the tailstock is improved; due to the error of the clamping pre-tightening force caused by the fatigue of the center point, the problem of the attenuation of the clamping force caused by the operating temperature and operating frequency of the servo motor is effectively avoided by dynamically compensating the pre-tightening force, and the operating accuracy and stability of the tailstock are improved.

[0025] Further, by setting a bed guide rail and a servo motor in the device of the present invention, through the cooperation of the driving torque of the ball screw and the closed-loop control of the servo motor, the precise movement of the tailstock can be realized. The servo motor directly drives the guide rail, reducing the clearance error of the traditional gear drive. The response time is reduced, improving the leveling efficiency of the workpiece; the integrated design of the servo motor and the bed guide rail integrates the driving components inside the machine tool, saving installation space.

[0026] Further, by setting a preset first translation distance difference and a preset second translation distance difference in the device of the present invention, when an error occurs due to the deflection deformation of the workpiece, a compliant control is performed using an S-shaped acceleration curve by monitoring the distance between the center point and the workpiece with a laser rangefinder and combining the load feedback of the servo motor. The high inflection point of the curve can suppress overshoot and reduce mechanical shock, reducing the system oscillation caused by resisting the flexural force during the alignment and clamping process of the center point, thereby reducing the machine tool loss caused by the impact, and improving the accuracy during the docking process of the long workpiece.

[0027] Further, by setting a preset second fluctuation value in the device of the present invention, since the impurities, dust and metal chips in the top groove of the workpiece cause an error in the load equivalent received by the control system, the air flow in the space of the top groove is promoted by reciprocating motion, and the impurities on the contact surface are actively removed by the contact friction between the center point and the top groove to increase the stability and accuracy of positioning and clamping, thereby increasing the reliability of positioning and clamping under contaminated working conditions.

[0028] Furthermore, by setting a preset length variation in the device of the present invention, due to the fatigue of the servo motor and the center causing the clamping force to decay, which in turn reduces the accuracy of the machine tool in machining the workpiece. By adopting the way of rotational following first, it avoids exacerbating the wear of the center due to rigid contact, while ensuring the uniform distribution of the contact pressure. During the rotational following stage, the center can adapt to the small eccentricity and shape error of the workpiece, self-adjust the contact position to reduce vibration. By compensating the tightening force during the following process, it avoids the fatigue of the center caused by a one-time application and the clamping failure caused by stress concentration. By determining the fixing force of the center according to the actual working conditions, it reduces the workpiece damage and machining error caused by over-tightening or loose delivery, and realizes the increase in the stability of the tailstock operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the overall structural schematic diagram of the programmable servo torque tailstock according to the embodiment of the present invention;

[0030] Figure 2 is the structural schematic diagram of the tailstock body of the programmable servo torque tailstock according to the embodiment of the present invention;

[0031] Figure 3 is the overall structural block diagram of the programmable servo torque tailstock according to the embodiment of the present invention;

[0032] Figure 4 is the structural block diagram of the clamping mechanism of the programmable servo torque tailstock according to the embodiment of the present invention;

[0033] Explanation of the reference numerals in the drawings: 1 - tailstock body, 2 - servo motor, 3 - bed guide rail, 4 - tailstock carriage, 5 - center, 6 - rotating bushing, 7 - locking element, 8 - cavity, 9 - second laser rangefinder. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0036] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0037] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0038] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 as shown, which are respectively the overall structure schematic diagram, the tailstock body structure schematic diagram, the overall structure block diagram, and the clamping mechanism structure block diagram of the programmable servo torque tailstock according to the embodiments of the present invention. An embodiment of the present invention provides a programmable servo torque tailstock, comprising:

[0039] A clamping mechanism, including a tailstock body 1 for supporting a workpiece, a tightening assembly connected to the tailstock body for clamping the workpiece, a tailstock support plate arranged below the tailstock body for driving the tailstock body to move parallel to a target working position, and a first controller connected to the tightening assembly for adjusting the initial clamping mode of the workpiece operation according to the horizontal length change amount of the cavity 8 in the tailstock body 1.

[0040] Wherein, the tightening assembly includes a rotating shaft sleeve 6 connected to the tailstock body 1, a center point 5 connected to the rotating shaft sleeve 6 for transmitting a tightening torque to the top groove of the workpiece, and a locking element 7 arranged inside the rotating shaft sleeve for locking the rotating shaft sleeve.

[0041] A moving mechanism, connected to the clamping mechanism for transporting the clamping mechanism to a corresponding position, including a bed guide rail passing through the tailstock support plate for determining the moving direction of the tailstock support plate, a servo motor connected to the bed guide rail for providing a rotational driving force to the bed guide rail, and a second controller connected to the servo motor for determining the moving mode of the tailstock body according to the translation distance difference of the center point, and adjusting the entering mode of the center point into the top groove according to the fluctuation value of the load equivalent of the motor shaft.

[0042] A detection mechanism, connected to the clamping mechanism, including a first laser rangefinder (not shown in the figure) arranged above the tailstock body 1 for detecting the horizontal distance between the center point 5 and the inner wall of the top groove, and a second laser rangefinder 9 for detecting the horizontal length of the cavity 8 in the tailstock body 1.

[0043] Specifically, the moving mechanism further includes a numerical control system control panel, a servo motor 2 driver, and a servo motor 2 drive circuit.

[0044] In implementation, the device of the present invention is provided with a clamping mechanism, a moving mechanism and a detection mechanism. Since the workpiece is too long and heavy, the workpiece cannot be kept horizontal before positioning, which leads to inaccurate clamping by the center tip 5. The detection mechanism monitors the deviation between the translation distance of the clamping component and the theoretical value in real time. The servo motor 2 adjusts the acceleration curve of the movement of the tailstock body 1 based on the dynamic translation distance difference. By adopting a flexible motion control strategy, it can actively compensate for the flexural deformation of the workpiece caused by its own weight, ensuring that the ultra-long and overweight workpiece always maintains a horizontal posture during the positioning process. Due to impurities in the top groove, the positioning function of the tailstock is unstable when the machine tool processes the workpiece. Due to foreign matters such as metal chips and coolant residues in the top groove of the workpiece, it affects the recognition effect of the load equivalent of the pre-tightening force of the servo motor 2. By adjusting the entry method and using the entry of the center tip 5 to reduce the residues in the top groove, the working stability of the tailstock is improved. Due to the error of the clamping pre-tightening force caused by the fatigue of the center tip 5, by dynamically compensating the pre-tightening force, the problem of the attenuation of the clamping force of the servo motor 2 caused by the operating temperature and operating frequency is effectively avoided, and the operating accuracy and stability of the tailstock are improved.

[0045] Specifically, a ball screw is arranged inside the tailstock support plate 4, and the ball screw is slidably connected to the guide rail.

[0046] In implementation, the device of the present invention is provided with a bed guide rail 3 and a servo motor 2. By cooperating with the driving torque of the ball screw and the closed-loop control of the servo motor 2, the precise movement of the tailstock can be realized. The servo motor 2 directly drives the guide rail, reducing the clearance error of the traditional gear drive. The response time is reduced, improving the leveling efficiency of the workpiece. The integrated design of the servo motor 2 and the bed guide rail 3 integrates the driving component inside the machine tool, saving installation space.

[0047] Specifically, the second controller is connected to the servo motor to obtain the load equivalent of the motor shaft when the servo motor is running. If the load equivalent is greater than or equal to the no-load load equivalent, it is determined that the clamping component contacts the inner wall of the top groove.

[0048] Specifically, the load equivalent is the moment of inertia that resists the change in rotational speed when the servo motor drives the tailstock body to move, and the no-load load equivalent is the moment of inertia before the servo motor drives the tailstock body to move without contacting the workpiece. The no-load load equivalent is positively correlated with the weight of the clamping mechanism.

[0049] Specifically, the second controller is respectively connected to the servo motor and the first laser rangefinder, and is used to respectively obtain the translation distance when the tightening component contacts the inner wall of the top groove and the theoretical distance between the tightening component and the inner wall of the top groove, calculate the translation distance difference, determine that the docking accuracy does not meet the requirements according to the comparison result that the translation distance difference is greater than or equal to the preset first translation distance difference, and control the output torque of the servo motor to operate according to the S-shaped acceleration curve according to the translation distance difference being greater than or equal to the preset second translation distance difference.

[0050] Specifically, the acceleration change rate at the high inflection point of the S-shaped acceleration curve is positively correlated with the translation distance difference; the translation distance difference is the difference between the theoretical distance and the translation distance, and the preset first translation distance difference is less than the preset second translation distance difference.

[0051] Among them, the S-shaped acceleration curve is the acceleration curve of the output torque changing with time.

[0052] Specifically, the control process of the acceleration of the output torque of the servo motor 2 operating according to the S-shaped acceleration curve is as follows: the acceleration of the acceleration of the output torque linearly increases from 0 to the maximum value, that is, the acceleration at the high inflection point of the S-shaped acceleration curve, keeps the maximum acceleration constant, the maximum acceleration linearly decreases to 0, the output torque after the acceleration drops to 0 is constant, the acceleration linearly decreases from 0 to the negative maximum value again, keeps the negative maximum value constant, and the acceleration linearly rises from the negative maximum value to 0.

[0053] Specifically, the abscissa of the S-shaped acceleration curve is time t, and the ordinate is acceleration a.

[0054] The acceleration change rate at the high inflection point of the S-shaped acceleration curve is the maximum jerk of the output torque of the servo motor 2.

[0055] Specifically, the theoretical distance is determined by the distance of the tailstock body 1 on the bed guide rail 3 and the length of the workpiece. The determination method of the distance is the prior art well-known to those skilled in the art and will not be elaborated here.

[0056] Specifically, under the conditions that the depth of the top groove is 2 cm and the apex angle of the center point 5 is 35°, the general value range of the preset first translation distance difference is [0.12 mm, 0.2 mm], and the general value range of the preset second translation distance difference is [0.3 mm, 0.5 mm].

[0057] Preferably, the preferred embodiment of the preset first translation distance difference is 0.15 mm, and the preferred embodiment of the preset second translation distance difference is 0.34 mm.

[0058] In implementation, by setting a preset first translation distance difference and a preset second translation distance difference, the device of the present invention monitors the distance between the center tip 5 and the workpiece through a laser rangefinder and combines the load feedback of the servo motor 2. When an error caused by the flexural deformation of the workpiece occurs, a compliant control is performed using an S-shaped acceleration curve. The high inflection point of the curve can suppress overshoot and reduce mechanical shock, reducing system oscillation caused by resisting the flexural force during the alignment and clamping process of the center tip 5, thereby reducing the machine tool loss caused by the impact and achieving an improvement in the accuracy during the docking process of long workpieces.

[0059] Specifically, the second controller is respectively connected to the servo motor 2 and the first laser rangefinder, and is used to preliminarily determine that the loading stability does not meet the requirements under the condition that the translation distance difference is greater than or equal to the preset first translation distance difference and less than the preset second translation distance difference, and obtain the load equivalent after determining that the tightening component contacts the inner wall of the top groove to calculate the fluctuation value of the load equivalent;

[0060] According to the fact that the fluctuation value is greater than or equal to the preset second fluctuation value, it is determined for the second time that the loading stability does not meet the requirements, and a stability loading action is performed as the entry method for the tightening component to enter the top groove.

[0061] Specifically, the fluctuation value of the load equivalent is the difference between the maximum value and the minimum value of the load equivalent within the loading duration; the preset first fluctuation value is less than the preset second fluctuation value.

[0062] Specifically, the stability loading action is that the servo motor 2 controls the tailstock body 1 to approach the top groove at a preset speed to a preset distance and then retreats reversely out of the top groove, and the stability loading action is repeated at least once.

[0063] Specifically, under the condition that the depth of the top groove is 2 cm, the general value range of the number of repetitions is [3 times, 6 times], and the preferred embodiment of the number of repetitions is 5 times.

[0064] Specifically, under the condition that the weight of the tailstock is 20 kg and the length of the tailstock is 25 cm, the general value range of the preset first fluctuation value is [0.8 N, 1.5 N], and the general value range of the preset second fluctuation value is [2 N, 4 N].

[0065] Preferably, the preferred embodiment of the preset first fluctuation value is 1 N, and the preferred embodiment of the preset second fluctuation value is 3 N.

[0066] In implementation, by setting a preset second fluctuation value, due to impurities, dust, and metal debris in the workpiece top groove, an error occurs in the load equivalent received by the control system. By promoting the air flow in the space of the top groove through reciprocating motion and actively removing impurities on the contact surface by the contact friction between the center point 5 and the top groove to increase the stability and accuracy of positioning and clamping, the reliability of positioning and clamping under contaminated working conditions is increased.

[0067] Specifically, the first controller is respectively connected to the tightening assembly and the second laser rangefinder, and is used to preliminarily determine that the stability of the center point does not meet the requirements under the condition that the fluctuation value of the load equivalent is greater than or equal to a preset first fluctuation value and less than a preset second fluctuation value, and calculate the change amount of the horizontal length according to the horizontal length of the cavity in the tailstock body.

[0068] According to that the change amount of the horizontal length is greater than or equal to a preset length change amount, it is determined for the second time that the stability of the center point does not meet the requirements, and the tightening assembly is controlled to adopt an active starting clamping method.

[0069] Specifically, when the length of the tightening assembly is 10 cm and the maximum diameter is 4 cm, the general value range of the preset length change amount is [0.1 mm, 0.4 mm], and the preferred embodiment of the preset length change amount is 0.15 mm.

[0070] Specifically, the change amount of the horizontal length is the difference between the horizontal length of the cavity under the condition that the load equivalent is equal to the no-load load equivalent and the horizontal length of the cavity under the condition that the load equivalent is equal to a preset pre-tightening force.

[0071] The active starting clamping method is that when the tightening assembly rotates following the workpiece, a tightening force compensation is applied until the center point fixing force, and then the rotating shaft sleeve is locked.

[0072] Specifically, the center point fixing force is equal to the sum of the product of the preset tightening force and the safety factor k and the cutting force of the workpiece.

[0073] Specifically, the value range of the safety factor k is [1.1, 1.5].

[0074] Specifically, the tightening assembly is a center point rotating tapered shaft sleeve.

[0075] Specifically, the locking element is a magnetic locking element.

[0076] In implementation, by setting a preset length variation amount in the device of the present invention, due to the fatigue of the servo motor 2 and the center 5 during operation, the clamping force attenuates, resulting in a reduction in the machining accuracy of the machine tool for the workpiece. By means of the rotation-following method first, it is possible to avoid exacerbating the wear of the center 5 due to rigid contact, while ensuring a uniform distribution of the contact pressure. During the rotation-following stage, the center 5 can adapt to the minor eccentricity and shape error of the workpiece, self-adjust the contact position to reduce vibration, compensate for the tightening force during the following process to avoid center fatigue caused by a one-time application and clamping failure caused by stress concentration, and determine the fixing force of the center 5 according to the actual working conditions to reduce workpiece damage and machining errors caused by over-tightening or looseness, thereby increasing the stability of the tailstock operation.

[0077] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A programmable servo torque tailstock, characterized in that, Comprising: A clamping mechanism, including a tailstock body for supporting a workpiece, a clamping component connected to the tailstock body for clamping the workpiece, a tailstock carriage disposed below the tailstock body for driving the tailstock body to move parallel to a target working position, and a first controller connected to the clamping component for adjusting the initial clamping mode of the workpiece operation according to the change amount of the horizontal length of the cavity in the tailstock body; Wherein, the clamping component includes a rotating shaft sleeve connected to the tailstock body, a center point connected to the rotating shaft sleeve for transmitting a clamping torque to the top groove of the workpiece, and a locking element disposed inside the rotating shaft sleeve for locking the rotating shaft sleeve; A moving mechanism, connected to the clamping mechanism for transporting the clamping mechanism to a corresponding position, including a bed guide rail passing through the tailstock carriage for determining the moving direction of the tailstock carriage, a servo motor connected to the bed guide rail for providing a rotational driving force to the bed guide rail, and a second controller connected to the servo motor for determining the moving mode of the tailstock body according to the translation distance difference of the center point, and adjusting the entering mode of the center point into the top groove according to the fluctuation value of the load equivalent of the motor shaft; A detection mechanism, connected to the clamping mechanism, including a first laser rangefinder disposed above the tailstock body for detecting the horizontal distance between the center point and the inner wall of the top groove, and a second laser rangefinder for detecting the horizontal length of the cavity in the tailstock body; Wherein, the second controller is respectively connected to the servo motor and the first laser rangefinder, and is used for initially determining that the loading stability does not meet the requirements under the condition that the translation distance difference is greater than or equal to a preset first translation distance difference and less than a preset second translation distance difference, and obtaining the load equivalent after determining that the clamping component contacts the inner wall of the top groove to calculate the fluctuation value of the load equivalent; Secondarily determining that the loading stability does not meet the requirements according to the fluctuation value being greater than or equal to a preset second fluctuation value, and performing a stability loading action as the entering mode of the clamping component into the top groove; The first controller is respectively connected to the clamping component and the second laser rangefinder, and is used for initially determining that the center point stability does not meet the requirements under the condition that the fluctuation value of the load equivalent is greater than or equal to a preset first fluctuation value and less than a preset second fluctuation value, and calculating the change amount of the horizontal length according to the horizontal length of the cavity in the tailstock body; Secondarily determining that the center point stability does not meet the requirements according to the change amount of the horizontal length being greater than or equal to a preset length change amount, and controlling the clamping component to adopt a movable initial clamping mode.

2. The programmable servo torque tailstock according to claim 1, characterized in that, The second controller is connected to the servo motor for obtaining the load equivalent of the motor shaft during the operation of the servo motor, and if the load equivalent is greater than or equal to the no-load load equivalent, it is determined that the clamping component contacts the inner wall of the top groove.

3. The programmable servo torque tailstock according to claim 2, characterized in that, The second controller is respectively connected to the servo motor and the first laser rangefinder, and is used to respectively obtain the translation distance when the tightening assembly contacts the inner wall of the top groove and the theoretical distance between the tightening assembly and the inner wall of the top groove, calculate the translation distance difference, determine that the docking accuracy does not meet the requirements according to the comparison result that the translation distance difference is greater than or equal to a preset first translation distance difference, and control the output torque of the servo motor to operate according to an S-shaped acceleration curve according to the translation distance difference being greater than or equal to a preset second translation distance difference.

4. The programmable servo torque tailstock according to claim 3, wherein, The acceleration change rate at the high inflection point of the S-shaped acceleration curve is positively correlated with the translation distance difference; the translation distance difference is the difference between the theoretical distance and the translation distance, and the preset first translation distance difference is less than the preset second translation distance difference. Wherein, the S-shaped acceleration curve is the acceleration curve of the output torque changing with time.

5. The programmable servo torque tailstock according to claim 1, characterized in that, The fluctuation value of the load equivalent is the difference between the maximum value and the minimum value of the load equivalent within the loading duration; the preset first fluctuation value is less than the preset second fluctuation value.

6. The programmable servo torque tailstock according to claim 1, characterized in that, The stable loading action is that the servo motor controls the tailstock body to approach the top groove at a preset speed to a preset distance and then reversely retreat out of the top groove, and repeats the stable loading action at least once.

7. The programmable servo torque tailstock according to claim 1, wherein, The horizontal length change amount is the difference between the horizontal length of the cavity under the condition that the load equivalent is equal to the no-load load equivalent and the horizontal length of the cavity under the condition that the load equivalent is equal to the preset pre-tightening force. The active starting clamping method is to lock the rotating shaft sleeve when the tightening assembly applies a tightening force compensation to the tip fixing force during the process of rotating and following the workpiece.

8. The programmable servo torque tailstock according to claim 1, wherein, A ball screw is arranged inside the tailstock carriage, and the ball screw is slidably connected to the guide rail.

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