CN113021053A - Self-healing test device and method for precision of feeding shaft of numerical control machine tool - Google Patents
Self-healing test device and method for precision of feeding shaft of numerical control machine tool Download PDFInfo
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- CN113021053A CN113021053A CN202110274054.7A CN202110274054A CN113021053A CN 113021053 A CN113021053 A CN 113021053A CN 202110274054 A CN202110274054 A CN 202110274054A CN 113021053 A CN113021053 A CN 113021053A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q5/00—Driving or feeding mechanisms; Control arrangements therefor
- B23Q5/22—Feeding members carrying tools or work
- B23Q5/34—Feeding other members supporting tools or work, e.g. saddles, tool-slides, through mechanical transmission
- B23Q5/38—Feeding other members supporting tools or work, e.g. saddles, tool-slides, through mechanical transmission feeding continuously
- B23Q5/40—Feeding other members supporting tools or work, e.g. saddles, tool-slides, through mechanical transmission feeding continuously by feed shaft, e.g. lead screw
- B23Q5/402—Feeding other members supporting tools or work, e.g. saddles, tool-slides, through mechanical transmission feeding continuously by feed shaft, e.g. lead screw in which screw or nut can both be driven
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q15/00—Automatic control or regulation of feed movement, cutting velocity or position of tool or work
- B23Q15/007—Automatic control or regulation of feed movement, cutting velocity or position of tool or work while the tool acts upon the workpiece
- B23Q15/12—Adaptive control, i.e. adjusting itself to have a performance which is optimum according to a preassigned criterion
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
Provided are a self-healing test device and method for precision of a feeding shaft of a numerical control machine tool. The pretightening force adjusting nut pair comprises a screw nut, a central body supporting sleeve and three monitoring-executing mechanisms which are uniformly distributed in the sleeve. The monitoring-actuating mechanism consists of a piezoelectric ceramic actuator, a flexible tail end, a force distribution cap and a pressure sensor. The signal collecting-feedback system comprises an industrial computer, a collecting card, a charge amplifier and a piezoelectric amplifier. The industrial computer adopts a PID control method to realize closed-loop regulation and control of the constant pretightening force according to the input and output voltage quantity. The device realizes the functions of automatic acquisition and active regulation and control of the pretightening force of the screw-nut pair, overcomes the defects of insufficient controllability, unreasonable structural design and the like of the conventional pretightening force regulating device, solves the problem of reduced machine tool precision retentivity caused by abrasion of the screw-nut pair, provides a basis for developing the precision retentivity and stability tests of the feed shaft, and has important reference significance for the precision design of the feed shaft of the numerical control machine tool.
Description
Technical Field
The invention belongs to the technical field of precision maintaining of numerical control machines, and particularly relates to a precision self-healing test device and method for a feed shaft of a numerical control machine.
Background
The positioning accuracy of the feed shaft is one of important factors influencing the accuracy of the numerical control machine tool. In the working process of the machine tool, the machining precision of the screw-nut pair is gradually declined under the influence of factors such as mechanical abrasion and the like, and the precision retentivity is reduced along with the decline. In the actual production process, the problem of reduced precision retentivity caused by part abrasion, failure and the like is mainly solved by means of positioning error compensation, and machine tool parts need to be replaced under severe conditions. However, the problem caused by abrasion cannot be solved essentially by performing positioning compensation on the feeding shaft regularly, and the difficulty of positioning compensation is increased and the accuracy of positioning compensation is reduced due to the complex change of the working state caused by the abrasion of the screw nut pair. On the other hand, the problem that the lead screw nut pair is worn and torn and brought can fundamentally be solved to the change lathe spare part, but production facility shut down can reduce production efficiency, increases manufacturing cost, and the debugging work after changing spare part also is very hard and time consuming.
The abrasion of the screw nut pair can cause the generation of the reverse error of the feed shaft, thereby influencing the bidirectional positioning precision of the feed shaft. The reverse clearance is mainly influenced by the pre-tightening state of the screw nut pair. The pretightening force is an important factor influencing the bidirectional positioning precision of the screw rod. If the automatic adjustment of the pretightening force of the screw nut pair can be realized, the pretightening force is not changed along with the abrasion of the screw nut pair, the reverse clearance error and the bidirectional positioning error can be inhibited, and the precision retentivity of the machine tool feed shaft is improved.
In 2016, Drosel et al IFAC PAPERSONLINE 49 curling-wave watch article Evaluation of Shape Memory Alloy Actuators for Wear Compensation in Ball Screen Drives, proposed a method for reducing the loss of precision caused by Wear of parts by using Shape Memory Alloy instead of double-nut spacers, which is not sufficient in controllability. In 2017, Wang et al, JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING, 39 th curling watch article Design OF new giant positive structural for double-nut shell screw pre-lighting, adopts a form OF a giant magnetostrictive lever to adjust THE pretightening force OF a screw-nut pair, but THE device is arranged outside THE screw-nut and has no practicability. In 2015, a device for adjusting the pretightening force of a workbench by using piezoelectric ceramics was invented in 201510167990.2 of Lihuhllin et al.
Disclosure of Invention
The invention mainly solves the technical problems of overcoming the defects of the existing pretightening force adjusting device, and provides a self-healing test device for the precision of a feed shaft of a numerical control machine tool aiming at the problems of insufficient controllability, unreasonable structural design and the like of the existing pretightening force adjusting device.
The technical scheme of the invention is as follows:
a self-healing test device for precision of a feed shaft of a numerical control machine tool comprises a pretightening force adjusting nut pair, a monitoring-executing mechanism and a signal acquisition-feedback system;
the pre-tightening force adjusting nut pair realizes bidirectional pre-tightening through the left nut 2 and the right nut 5; a central body supporting sleeve 3 is arranged between the double nuts, and is fixed in the middle of the double nuts through three positioning bolts 4 which are uniformly distributed, and is used for installing a monitoring-executing mechanism; the central body supporting sleeve 3 and the right nut are fixed through six central body fixing bolts 6 which are uniformly distributed, so that the central body supporting sleeve 3 is prevented from moving in the extension process of the piezoelectric ceramic actuator 11; the central body supporting sleeve 3 reserves a space and an opening for a monitoring-actuating mechanism for adjustment and observation;
the monitoring-actuating mechanisms are three groups and are uniformly distributed in the central body supporting sleeve 3; the monitoring-executing mechanism mainly comprises a piezoelectric ceramic actuator 11, a flexible tail end 10, a force distribution cap 9 and a pressure sensor 8; the piezoelectric ceramic actuator 11 is fixed on the left nut 2 through a piezoelectric ceramic actuator fixing bolt 12, and the pressure sensor 8 is fixed on the right nut 5 through a pressure sensor fixing bolt 7; the piezoelectric ceramic actuator 11 is connected with the pressure sensor 8 through the flexible tail end 10 and the force distribution cap 9 to realize force transmission;
the signal acquisition-feedback system comprises an industrial computer, an acquisition card, a charge amplifier and a piezoelectric amplifier; the charge quantity signal generated by the pressure sensor 8 is converted into a voltage analog quantity of-10V to +10V through a charge amplifier and is input into a collection card for collection; the output acquisition card outputs 0-10V voltage signals, the voltage signals are amplified by a piezoelectric amplifier to be 10 times of the original voltage signals, the extension range of the piezoelectric ceramic actuator 11 is 0-15 mu m, and the voltage and the extension amount are in a linear relation; the industrial computer adopts a PID control method to realize closed-loop regulation and control of the constant pretightening force according to the input and output voltage quantity.
A self-healing test method for precision of a feed shaft of a numerical control machine tool comprises the following specific steps:
first, the installation accuracy self-healing test device
A pre-tightening force adjusting nut pair with a precision self-healing device is arranged on a feed shaft screw rod of the machine tool, and the device realizes the fixation of a left nut 2, a right nut 5 and a central body supporting sleeve 3 through a positioning bolt 4; three uniformly distributed installation monitoring-executing mechanisms are arranged in the central body supporting sleeve 3; the pressure sensor 8 is connected with the input acquisition card through a charge amplifier, and the output acquisition card is connected with the piezoelectric ceramic actuator 11 through a piezoelectric amplifier;
second, pre-tightening force of screw is set
Pre-tightening the pre-tightening force adjusting nut pair, respectively measuring the pressure values of the three monitoring-executing mechanisms, adjusting the voltage value of the piezoelectric amplifier, and enabling the pressure values of the three monitoring-executing mechanisms to be equal through changing the initial elongation of the piezoelectric ceramic actuator 11;
thirdly, the pre-tightening force of the screw rod is automatically adjusted
Along with the continuous work of the machine tool, the by-product of the pretightening force adjusting nut is abraded, a gap is generated between the nut and the screw rod 1, and the pretightening force is changed; the quantity of electric charge generated by the pressure sensor changes, and the industrial computer adjusts the output voltage by adopting a PID control method according to the change of the input voltage, so that the pretightening force is kept constant.
The invention has the beneficial effects that: the problem of the lathe precision retentivity decline that leads to because screw nut pair wearing and tearing is solved, overcome defects such as current pretightning force adjusting device controllability is not enough, structural design is unreasonable, realized the automatic acquisition and the initiative regulation and control function of screw nut pair pretightning force, for developing feed shaft precision retentivity and stability test provide the basis, also have important reference meaning to numerical control machine tool feed shaft precision design.
Drawings
FIG. 1 is a front view of a pretension adjusting device;
FIG. 2 is a top view of the pretension adjusting device;
FIG. 3 is a schematic view of a monitor-actuator;
FIG. 4 is a schematic diagram of an experiment platform system framework;
FIG. 5 is a schematic diagram of constant pretension PID control;
FIG. 6 is a schematic view of a pretension regulation system;
in the figure: 1, a lead screw; 2, a left nut; 3 central body support sleeve; 4, positioning a bolt; 5, a right nut; 6 central body fixing bolt; 7, fixing a bolt of the pressure sensor; 8, a pressure sensor; a 9-force distribution cap; 10 a flexible tip; 11 a piezoelectric ceramic actuator; 12 piezoceramic actuator fixing bolts.
Detailed Description
The following detailed description of the embodiments of the invention refers to the accompanying drawings and claims.
As shown in fig. 1, the monitoring-actuating mechanisms are uniformly distributed in the central body supporting sleeve 3, the central body supporting sleeve 3 is fixed with the right-side nut 5 through six uniformly distributed central body fixing bolts 6, and the central body supporting sleeve 3 is fixed with the left-side nut 2 and the right-side nut 5 through three uniformly distributed positioning bolts 4. The pre-tightening force adjusting nut pair realizes bidirectional pre-tightening through the left side nut 2 and the right side nut 5. The central body support sleeve 3 is in clearance fit with the lead screw 1 to ensure the lead screw to rotate freely therein.
As shown in fig. 2, the monitoring-actuator includes a piezoceramic actuator 11, a flexible tip 10, a force distribution cap 9, and a pressure sensor 8. The piezoceramic actuator 11 is fixed to the left-side nut 2 by a piezoceramic actuator fixing bolt 12, and the pressure sensor 8 is fixed to the right-side nut 5 by a pressure sensor fixing bolt 7. The piezoceramic actuator 11 is connected to the pressure sensor 8 via the flexible tip 10 and the force distribution cap 9.
The signal acquisition-feedback system comprises an industrial computer, an acquisition card, a charge amplifier and a piezoelectric amplifier, as shown in fig. 5, a pressure sensor 8 is connected with an input acquisition card through the charge amplifier, and an output acquisition card is connected with a piezoelectric ceramic actuator 11 through the piezoelectric amplifier. The output acquisition card and the input acquisition card are respectively connected with the industrial computer.
The automatic pretightening force regulating and controlling device comprises the following specific steps:
firstly, a precision self-healing test device is installed.
A pretightening force adjusting nut pair is arranged on a feed shaft screw rod of a machine tool, and the device realizes the fixation of a left nut 2, a right nut 5 and a central body supporting sleeve 3 through a positioning bolt 4. Three uniformly distributed installation monitoring-actuating mechanisms are arranged in the central body supporting sleeve 3 and consist of a piezoelectric ceramic actuator 11, a flexible tail end 10, a force distribution cap 9 and a pressure sensor 8. The pressure sensor 8 is connected with the input acquisition card through a charge amplifier, and the output acquisition card is connected with the piezoelectric ceramic actuator 11 through a piezoelectric amplifier.
And secondly, pre-tightening force of the screw is set.
And pre-tightening the pre-tightening force adjusting nut pair, respectively measuring the pressure values of the three monitoring-executing mechanisms, adjusting the voltage value of the piezoelectric amplifier, and enabling the pressure values of the three monitoring-executing mechanisms to be equal through changing the initial elongation of the piezoelectric ceramic actuator 11.
And thirdly, automatically adjusting the pretightening force of the lead screw.
Along with the continuous work of the machine tool, the by-product of the pretightening force adjusting nut is abraded, a gap is formed between the nut and the screw rod, and the pretightening force is changed. The quantity of electric charge generated by the pressure sensor changes, and the industrial computer adjusts the output voltage by adopting a PID control method according to the change of the input voltage, so that the pretightening force is kept constant, as shown in FIG. 4.
It should be noted that the above-mentioned embodiments of the present invention are only used for illustrating the principle and flow of the present invention, and do not limit the present invention. Therefore, any modifications and equivalents made without departing from the spirit and scope of the present invention should be considered as included in the protection scope of the present invention.
Claims (2)
1. The self-healing test device for the precision of the feed shaft of the numerical control machine tool is characterized by comprising a pretightening force adjusting nut pair, a monitoring-executing mechanism and a signal acquisition-feedback system;
the pre-tightening force adjusting nut pair realizes bidirectional pre-tightening through the left nut (2) and the right nut (5); a central body supporting sleeve (3) is arranged between the double nuts, and is fixed in the middle of the double nuts through three positioning bolts (4) which are uniformly distributed and used for installing a monitoring-executing mechanism; the central body supporting sleeve (3) and the right nut are fixed through six central body fixing bolts (6) which are uniformly distributed, so that the central body supporting sleeve (3) is prevented from moving in the extension process of the piezoelectric ceramic actuator (11); the central body supporting sleeve (3) reserves a space and an opening for a monitoring-executing mechanism for adjustment and observation;
the monitoring-actuating mechanisms are divided into three groups and are uniformly distributed in the central body supporting sleeve (3); the monitoring-executing mechanism mainly comprises a piezoelectric ceramic actuator (11), a flexible tail end (10), a force distribution cap (9) and a pressure sensor (8); the piezoelectric ceramic actuator (11) is fixed on the left nut (2) through a piezoelectric ceramic actuator fixing bolt (12), and the pressure sensor (8) is fixed on the right nut (5) through a pressure sensor fixing bolt (7); the piezoelectric ceramic actuator (11) is connected with the pressure sensor (8) through the flexible tail end (10) and the force distribution cap (9) to realize force transmission;
the signal acquisition-feedback system comprises an industrial computer, an acquisition card, a charge amplifier and a piezoelectric amplifier; the charge quantity signal generated by the pressure sensor (8) is converted into a voltage analog quantity of-10V to +10V through a charge amplifier and is input into an acquisition card for acquisition; the output acquisition card outputs 0-10V voltage signals, the voltage signals are amplified by a piezoelectric amplifier to be 10 times of the original voltage signals, the extension range of the piezoelectric ceramic actuator (11) is 0-15 mu m, and the voltage and the extension amount are in a linear relation; the industrial computer adopts a PID control method to realize closed-loop regulation and control of the constant pretightening force according to the input and output voltage quantity.
2. The test method of the self-healing test device for the precision of the feed shaft of the numerical control machine is characterized by comprising the following specific steps of:
first, the installation accuracy self-healing test device
A pre-tightening force adjusting nut pair with a precision self-healing device is arranged on a feed shaft screw rod (1) of a machine tool, and the device realizes the fixation of a left nut (2), a right nut (5) and a central body supporting sleeve (3) through a positioning bolt (4); three uniformly distributed installation monitoring-executing mechanisms are arranged in the central body supporting sleeve (3); the pressure sensor (8) is connected with the input acquisition card through a charge amplifier, and the output acquisition card is connected with the piezoelectric ceramic actuator (11) through a piezoelectric amplifier;
second, pre-tightening force of screw is set
Pre-tightening the pre-tightening force adjusting nut pair, respectively measuring the pressure values of the three monitoring-executing mechanisms, adjusting the voltage value of the piezoelectric amplifier, and enabling the pressure values of the three monitoring-executing mechanisms to be equal through changing the initial elongation of the piezoelectric ceramic actuator (11);
thirdly, the pre-tightening force of the screw rod is automatically adjusted
Along with the continuous work of the machine tool, the by-product of the pretightening force adjusting nut is abraded, a gap is generated between the nut and the screw rod (1), and the pretightening force is changed; the quantity of electric charge generated by the pressure sensor changes, and the industrial computer adjusts the output voltage by adopting a PID control method according to the change of the input voltage, so that the pretightening force is kept constant.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110274054.7A CN113021053A (en) | 2021-03-15 | 2021-03-15 | Self-healing test device and method for precision of feeding shaft of numerical control machine tool |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110274054.7A CN113021053A (en) | 2021-03-15 | 2021-03-15 | Self-healing test device and method for precision of feeding shaft of numerical control machine tool |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60116424A (en) * | 1983-11-30 | 1985-06-22 | Mitsubishi Heavy Ind Ltd | Controlling method of revolutional number of feeder screw |
| JPS6435165A (en) * | 1987-07-29 | 1989-02-06 | Nikon Corp | Feed screw |
| DE102012005555B3 (en) * | 2012-03-21 | 2013-08-22 | Audi Ag | Measuring plate for use in bearing surface of slide damper of press for measuring tension-, pressure- or shear forces, has recesses, in which sensors are mounted under pre-tension for measuring forces by pressure piece |
| CN106017915A (en) * | 2016-05-11 | 2016-10-12 | 清华大学 | Ball screw assembly precision retaining testing apparatus with characteristics of precise pre tightening and loading |
| CN108775386A (en) * | 2018-04-26 | 2018-11-09 | 广州市昊志机电股份有限公司 | A kind of ball-screw back clearance automatic regulating system and method |
-
2021
- 2021-03-15 CN CN202110274054.7A patent/CN113021053A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60116424A (en) * | 1983-11-30 | 1985-06-22 | Mitsubishi Heavy Ind Ltd | Controlling method of revolutional number of feeder screw |
| JPS6435165A (en) * | 1987-07-29 | 1989-02-06 | Nikon Corp | Feed screw |
| DE102012005555B3 (en) * | 2012-03-21 | 2013-08-22 | Audi Ag | Measuring plate for use in bearing surface of slide damper of press for measuring tension-, pressure- or shear forces, has recesses, in which sensors are mounted under pre-tension for measuring forces by pressure piece |
| CN106017915A (en) * | 2016-05-11 | 2016-10-12 | 清华大学 | Ball screw assembly precision retaining testing apparatus with characteristics of precise pre tightening and loading |
| CN108775386A (en) * | 2018-04-26 | 2018-11-09 | 广州市昊志机电股份有限公司 | A kind of ball-screw back clearance automatic regulating system and method |
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Application publication date: 20210625 |
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