CN103909427B - A kind of composite excitation magnetic suspension feeding platform - Google Patents

Abstract

The invention discloses a hybrid excitation magnetic levitation feeding platform, which comprises a levitation workbench, a V-shaped guide rail and two linear motors. Among them, the suspended workbench is a frame structure matching the V-shaped guide rail structure, and the suspended workbench and the V-shaped guide rail are symmetrical about a central axis; two linear motors are installed on the suspended workbench and the V-shaped guide rail, and about the center Axisymmetric. Each linear motor includes a mover iron core and a stator iron core, the mover iron core is connected with the suspension workbench; the stator iron core is installed on a V-shaped guide rail. The invention realizes the simple structure of the magnetic levitation platform without adding any electromagnet, reduces the power consumption for levitation, saves the cost, reduces the complexity of the device at the same time, and can improve the levitation stability and positioning accuracy.

Description

A Hybrid Excitation Magnetic Levitation Feeding Platform

technical field

The invention relates to a feeding platform technology of a numerical control machine tool, in particular to a hybrid excitation magnetic levitation feeding platform.

Background technique

During the feeding process of CNC machine tools, there is friction between the moving parts and the guide rail, and the existence of this friction is harmful to the feeding movement. First, it increases the power loss of the drive system, reduces efficiency, motion accuracy and service life, and increases maintenance costs. Second, it generates motion noise and system heat, and even deforms delicate components. Due to the non-linear relationship between friction and motion speed, especially in the case of small amount and low-speed feed, this non-linear relationship is difficult to grasp, and may even cause crawling, which seriously damages the drive system for high speed. Performance requirements for precision and high responsiveness.

Industry R&D personnel are committed to applying magnetic levitation technology to the feeding system of CNC machine tools, hoping to solve all the above problems. Rong-JongWai et al. developed a long-stroke magnetic levitation linear positioning motion platform, which can realize large-stroke linear feed motion, but the platform cannot achieve ultra-precision motion. Chia-HsiangMenq et al. developed a high-precision maglev platform, tried various advanced control methods and finally improved the levitation accuracy of the platform to about tens of nanometers, but the platform can only achieve micro-movements with small strokes and cannot provide large Linear feed motion of stroke.

The patent "Industrial Applied Active Magnetic Levitation Machine Tool Guide Rail Linear Motor Feed Platform" applied by Zhang Gang et al. includes a guide rail fixed on the machine base, a mobile platform mounted on the guide rail and a linear motor. The linear motor is located in the center of the guide rail. The suspension electromagnet is set on the upper and lower sides of the guide rails on both sides, and the guide electromagnet is set on the two sides of the guide rail. The suspension electromagnet and the guide electromagnet are fixedly connected with the mobile platform. Displacement sensors are installed in the middle of them and connected to the mobile platform. position control system. Ge Yanjun and others applied for a patent "Magnetic Levitation Linear Feed System for CNC Machine Tool A New Type of Magnetic Levitation Linear Feed System for CNC Machine Tool" which mainly includes the machine base, two guide rails fixed on it, the stator part of the linear motor, and four Four pairs of differential suspension electromagnets at two corners, two pairs of guide electromagnets installed next to the suspension electromagnets, linear motor mover components installed under the workbench, grating measurement system and support devices installed on the guide rail.

The above-mentioned magnetic levitation feeding platform mainly adopts electromagnets to realize magnetic levitation, which has two defects. First, the vertical suspension force, horizontal guidance force, and horizontal driving force of the suspension system are independently generated by different systems, and the structure is relatively complex, and at least three controllers are required, including the suspension controller, the guidance controller, and the drive controller. There are many links to be controlled and the cost is expensive. Second, in addition to the useful electromagnetic driving force provided by the linear motor, there is also an inherent normal magnetic attraction force, which is often much larger than the electromagnetic driving force, and will change with the change of the armature current, thus affecting Suspension stability and positioning accuracy of the suspended platform.

Contents of the invention

The technical problem mainly solved by the present invention is to provide a hybrid excitation magnetic levitation feed platform, which uses a new type of hybrid excitation magnetic levitation mechanism as the feed mechanism of high-speed and high-precision CNC machine tools. The structure and control are relatively simple, and the feed platform can be improved. Excellent positioning accuracy and suspension stability.

In order to solve the above technical problems, a technical solution adopted by the present invention is to provide a hybrid excitation magnetic levitation feeding platform, which includes a levitation workbench, a V-shaped guide rail, and two linear motors. Among them, the suspended workbench is a frame structure that matches the V-shaped guide rail structure, and both the suspended workbench and the V-shaped guide rail are symmetrical structures about a central axis; two linear motors are installed on the suspended workbench and the V-shaped guide rail. , and is symmetrical about the central axis. Each linear motor includes a mover iron core and a stator iron core, the mover iron core is connected with the suspension workbench; the stator iron core is installed on a V-shaped guide rail.

In a preferred embodiment of the present invention, the hybrid excitation maglev feeding platform further includes a first direction eddy current sensor, a grating sensor, a second direction eddy current sensor, a first direction eddy current sensor and a second direction eddy current sensor It is set on the suspended workbench, and the grating sensor is set on the V-shaped track.

In a preferred embodiment of the present invention, the V-shaped guide rail includes a body, which includes a top surface, a side surface and a bottom surface, and the bottom surface is formed by two completely symmetrical inclined surfaces.

In a preferred embodiment of the present invention, the stator core is installed on the bottom surface of the body of the V-shaped guide rail, the excitation winding is arranged inside, and the permanent magnet is arranged on the surface.

In a preferred embodiment of the present invention, the suspended workbench is a non-enclosed frame formed by upper beams, side beams and cantilever; wherein, the upper beam, side beam and cantilever of the suspended workbench and the top of the V-shaped guide rail body The surface, the side surface and the bottom surface correspond to each other and are arranged in parallel with an appropriate distance.

In a preferred embodiment of the present invention, the mover iron core is connected to the cantilever of the suspended workbench, and an armature winding is arranged inside it.

In a preferred embodiment of the present invention, the first direction eddy current sensors are arranged symmetrically on the inner surface of the side beam of the suspended workbench.

In a preferred embodiment of the present invention, the inner surface of the upper beam of the suspended workbench is symmetrically provided with the second direction eddy current sensors.

In a preferred embodiment of the present invention, the grating sensors are arranged symmetrically on the top surface of the body of the V-shaped guide rail.

In a preferred embodiment of the present invention, the hybrid excitation maglev feeding platform further includes a control system, and the excitation winding, the armature winding, the eddy current sensor in the first direction, the eddy current sensor in the second direction and the grating sensor are connected to the control system.

The beneficial effects of the present invention are: the present invention proposes a V-shaped structure guide rail, two linear motors are arranged symmetrically; the linear motors are inverted and fed in a magnetic levitation mode, and the linear motors provide levitation force and guiding force at the same time; in order to simplify the control , using a hybrid excitation synchronous linear motor; through the combination of the special structure of the feed platform and the symmetrically arranged hybrid excitation linear motor, the simple structure of the magnetic levitation platform without any additional electromagnet is realized. Thus, the power consumption for levitation is reduced, the cost is saved, and the complexity of the device is reduced at the same time; the levitation stability can be improved by using the normal magnetic attraction force of the linear motor, which affects the stability and positioning accuracy of the levitation system, as the levitation force and guiding force and positioning accuracy. Since the driving force, suspension force and guiding force of the suspension system are all generated by the linear motor, the driving system, suspension system and guiding system are integrated into one, which simplifies the structure and reduces the control links.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work, wherein:

Fig. 1 is a structural schematic diagram of a hybrid excitation magnetic levitation feeding platform of the present invention.

Fig. 2 is a cross-sectional view of Fig. 1 along the dashed line A-A.

The marks of the components in the drawings are as follows: 1. Mover core; 2. Stator core; 3. Suspension table; 31. Upper beam; 32. Side beam; 33. Cantilever; 4. V-shaped guide rail; 41. Top surface ; 42, side; 43, bottom; 5, armature winding; 6, permanent magnet; 7, excitation winding; 8, first direction eddy current sensor; 9, grating sensor; 10, second direction eddy current sensor

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The purpose of the present invention is to provide a hybrid excitation magnetic levitation feed platform structure for the defects of the existing technology, which uses a new type of hybrid excitation magnetic levitation mechanism as the feed mechanism of high-speed high-precision CNC machine tools, and the structure and control are relatively simple , and at the same time well avoid the problems caused by the normal magnetic attraction force of the linear motor, which can improve the positioning accuracy and suspension stability of the feed platform.

As shown in Figures 1 and 2, the hybrid excitation maglev feeding platform of the present invention includes a V-shaped guide rail 4, a suspension workbench 3, a linear motor (not shown in the figure), an eddy current sensor 8 in the first direction, a grating sensor 9, and a second direction sensor. Eddy current sensor 10. The body of the V-shaped guide rail 4 includes a top surface 41 , a side surface 42 and a bottom surface 43 , the bottom surface of which is formed by two completely symmetrical inclined surfaces.

The suspended workbench 3 is a frame structure matching the structure of the V-shaped guide rail 4, and both the suspended workbench and the V-shaped guide rail are symmetrical structures about a central axis B-B. As shown in FIGS. 1 and 2 , the suspended workbench 3 is a non-enclosed frame formed by an upper beam 31 , a side beam 32 and a cantilever 33 . Wherein, the upper beam 31 , the side beam 32 and the cantilever 33 of the suspended workbench 3 correspond to and are arranged parallel to the top surface 41 , the side surface 42 and the bottom surface 43 of the V-shaped guide rail 4 body. In Fig. 1 and Fig. 2, the suspended workbench 3 is in a suspended state when it is working, that is, it will be in the state shown in Fig. 1 and 2 after power-on, and the suspended workbench 3 is placed on the V-shaped guide rail 4 body when it is not working on the top surface 41 of the.

Two linear motors are distributed symmetrically along the central axis B-B. The two linear motors have the same structure, here we take the linear motor on one side as an example for illustration. The stator core 2 is installed on the bottom surface 43 of the body of the V-shaped guide rail 4, and the excitation winding 7 is arranged inside it, and the permanent magnet 6 is arranged on the surface. The mover core 1 is connected to the cantilever 33 of the suspension table 3, and an armature winding 5 is arranged inside it.

The inner surface of the side beam 32 of the suspension workbench 3 is symmetrically provided with a first direction eddy current sensor 8, the inner surface of the upper beam 31 is symmetrically provided with a second direction eddy current sensor 10, and the upper surface 41 of the body of the V-shaped guide rail 4 is symmetrically provided with Grating sensor9. The second direction eddy current sensor 10 is used to measure the suspension displacement in the vertical z direction of the suspended workbench, the first direction eddy current sensor 8 is used to measure the guide displacement in the horizontal y direction of the suspended workbench, and the grating sensor 9 is used to measure the suspension workbench Feed displacement in the horizontal x direction.

In this embodiment, the vertical component Fz of the normal magnetic attraction force Fn of the two linear motors provides the levitation force, the horizontal component Fy provides the horizontal guiding force, and the electromagnetic thrust Fx of the linear motors provides the horizontal driving force. According to the characteristics of the hybrid excitation linear motor: the normal magnetic attraction is mainly determined by the excitation current, and the electromagnetic thrust is mainly determined by the armature current. Therefore, adjusting the excitation current can control the normal magnetic attraction force to achieve stable suspension; adjusting the armature current can control the horizontal driving force to achieve feed motion.

The excitation winding 7, the armature winding 5, the first direction eddy current sensor 8, the second direction eddy current sensor 10 and the grating sensor 9 are connected to the control system, and through the decoupling control algorithm, the feed platform x, y, z The movement in three directions can realize complete decoupling control, that is, the suspension, guidance and feeding of the magnetic levitation feeding platform are independent of each other and do not affect each other. The three opposite movements can be controlled separately without interfering with movements in other directions. Improve suspension stability and positioning accuracy.

It should be noted that: the structure of the hybrid excitation magnetic levitation feeding platform in the present invention is left-right symmetrical, only half of the structure is described in detail here, and the other half is completely the same.

The present invention aims at simplifying the structure and control of the direct-drive feed platform of the CNC machine tool, and proposes a V-shaped structure guide rail, with two linear motors arranged symmetrically; Guiding force; in order to simplify the control, a mixed excitation synchronous linear motor is used. The levitation force and guiding force are provided at the same time through the inversion of the linear motor; the combination of the special structure of the feed platform and the symmetrically arranged hybrid excitation linear motor realizes the simple structure of the magnetic levitation platform without any additional electromagnet.

In summary, the novel hybrid excitation magnetic levitation feeding platform proposed by the present invention has the following advantages:

(1) An electromagnet levitation system is not required, which reduces the power consumption for levitation, thereby saving costs and reducing the complexity of the device.

(2) Using the normal magnetic attraction force of the linear motor, which affects the stability and positioning accuracy of the suspension system, as the suspension force and guiding force, the suspension stability and positioning accuracy can be improved.

(3) The driving force, suspension force and guiding force of the suspension system are all generated by the linear motor, and the driving system, suspension system and guiding system are integrated into one, which simplifies the structure and reduces the control links.

The above descriptions are only examples of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the description of the present invention, or directly or indirectly used in other related technical fields, shall be The same reasoning is included in the patent protection scope of the present invention.

Claims (6)

1. a composite excitation magnetic suspension feeding platform, is characterized in that, it comprises suspension workMake platform (3), V-type rail (4), two linear motors, wherein, described suspension workbenchFor the frame structure matching with described V-type rail structure, described suspension workbench and described VType guide rail is both about a central axis symmetrical structure; Two linear motors are arranged onOn described suspension workbench and described V-type rail, and about described central axis symmetry; EachLinear motor includes mover core (1) and stator core (2); Described V-type rail bagDraw together by the bottom surface (43) that centrosymmetric two inclined-planes form completely, described suspension workbench bagDraw together the cantilever (33) that bottom surface is relative and the suitable distance of maintenance be arranged in parallel with described V-type rail;Described mover core (1) is arranged on the cantilever (33) of described suspension workbench (3), itsInside is provided with armature winding (5); Described stator core (2) is arranged on described V-type railBottom surface on, its inside is provided with Exciting Windings for Transverse Differential Protection (7); Described surface of stator core is provided with foreverMagnet (6);

Described composite excitation magnetic suspension feeding platform also comprises first direction current vortex sensor(8), grating sensor (9), second direction current vortex sensor (10), first direction electricityEddy current sensor and second direction current vortex sensor are arranged on described suspension workbench, gratingSensor setting is on described V-type rail;

Described composite excitation magnetic suspension feeding platform also comprises control system, described Exciting Windings for Transverse Differential Protection,Armature winding, first direction current vortex sensor, second direction current vortex sensor and grating passSensor is connected to described control system, and by Uncoupling Control Based, to realize x, y, z sideTo the full decoupled control of motion.

2. composite excitation magnetic suspension feeding platform according to claim 1, its feature existsIn, described V-type rail further comprises a body, it comprises end face (41), side (42)And bottom surface (43).

3. composite excitation magnetic suspension feeding platform according to claim 2, its feature existsIn, described suspension workbench is to be formed by upper beam (31), curb girder (32) and cantilever (33)Non-closed frame; Wherein, the upper beam of suspension workbench, curb girder and cantilever and V-type rail are originallyEnd face, side and the bottom surface of the body respectively suitable distance of corresponding and maintenance be arranged in parallel.

4. composite excitation magnetic suspension feeding platform according to claim 3, its feature existsIn, the curb girder inner surface of described suspension workbench is symmetrically arranged with described first direction current vortex and passesSensor.

5. composite excitation magnetic suspension feeding platform according to claim 3, its feature existsIn, the upper beam inner surface of described suspension workbench is symmetrically arranged with described second direction current vortex and passesSensor.

6. composite excitation magnetic suspension feeding platform according to claim 3, its feature existsIn, on the body end face of described V-type rail, be symmetrically arranged with described grating sensor.