CN100579694C - Non-round cutting device of digital control lathes and control method thereof - Google Patents

Abstract

The invention discloses a non-circular cutting device for a numerically controlled lathe, which comprises a cutter head, a cutter holder fixed with cutters, a displacement sensor, a main shaft coder, an actuator, and a controller, wherein the main shaft coder is arranged on a main shaft motor of the numerically controlled lathe. The non-circular cutting device is characterized in that the cutter head is provided with a first cavity and a second cavity which are communicated with each other, a flexible hinge structure is arranged in the first cavity integrally, the front end part of the flexible hinge structure is integrally provided with a permanent seat of the cutter holder, the cutter holder is fixedly arranged on the permanent seat of the cutter holder, the actuator is fixedly arranged in the second cavity, the end part of the actuator leans against the rear end face of the flexible hinge structure, the main shaft coder and the displacement sensor are both electrically connected with the controller, and the controller is electrically connected with the actuator. The non-circular cutting device has the advantages that the cutter head has the functions of micro positioning and precision cutting vibration control to realize micro feeding movements of the cutters in a non-circular precise cutting system, the cutting vibration in axial and tangential directions of a workpiece can be controlled effectively, and the turning precision of non-circular cutting is improved.

Description

A kind of non-round cutting device of numerically controlled lathe and control method thereof

Technical field

The present invention relates to a kind of topping machanism of numerically controlled lathe, especially relate to a kind of non-round cutting device and control method thereof of turning equipment.

Background technology

Come the Synchronization Control cutter in the radially displacement on (laterally) of workpiece according to the rotation period of main shaft, then can process the workpiece of noncircular sectional shape, this processing method is called Non-circular Section Turning.The method of processing on-circular cross-section profile mainly contains at present: copying, the special process and numerical control turning.Form copying utilizes the relative movement orbit of pattern control cutter and workpiece, forms required surface configuration, and this method range of work is wide, but the workpiece of processed complex cross sectional shape, but efficient is low, adjustment complexity and machining accuracy are relatively poor; The special process can be used for the fine finishining of non-round accessory, but processing cost is higher, efficient is low, and then is difficult to processing for all very complicated workpiece of cross section and shaft section shape; The process principle of numerical control turning is: in the process of on-circular cross-section workpiece, cutter is gone up at directions X (laterally) and is followed the tracks of the main axis rotation angle, adjust the tool position in real time, realize the reciprocating motion of cutter in X-direction, thereby process required non-round line, but the response frequency of digital control system X-axis can not satisfy the reciprocating requirement of high speed at present, and the precision of turning processing is not ideal enough.

Summary of the invention

Technical problem to be solved by this invention provides a kind of non-round cutting device and control method thereof that can improve the numerically controlled lathe of turning machining accuracy.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of non-round cutting device of numerically controlled lathe, comprise knife rest, be fixed with the cutter holder of cutter, displacement transducer, spindle encoder, actuator and controller, described spindle encoder is arranged on the spindle motor of numerically controlled lathe, described displacement transducer is fixedly installed on the described knife rest, described knife rest is provided with first cavity and second cavity that is interconnected, be wholely set the flexible hinge structure in described first cavity, the leading section of described flexible hinge structure has been wholely set the cutter holder holder, described cutter holder is fixedly installed on the described cutter holder holder, be set with the metallic rod of responding to mutually with described displacement transducer on the described cutter holder holder, described actuator is arranged in described second cavity, described flexible hinge structure comprises back seat, the leading section apical grafting of described actuator is on the rear end face of described back seat, be wholely set two parallelogram elastic mechanisms between described back seat and the described cutter holder holder along the center line symmetry, described spindle encoder and described displacement transducer all are electrically connected with described controller, and described controller is electrically connected with described actuator.

Described parallelogram elastic mechanism comprises head rod longitudinally, second connecting rod and two the 3rd horizontal connecting rods, described head rod is connected by the 4th horizontal connecting rod one with described cutter holder holder, described second connecting rod is connected with described back seat one, described the 3rd connecting rod is connected with described knife rest one, the junction of described the 4th connecting rod and described cutter holder holder, the junction of described the 4th connecting rod and described head rod, the junction of described head rod and described the 3rd connecting rod, the junction of described the 3rd connecting rod and described second connecting rod, described second connecting rod and the junction of described back seat be provided with two back to half slot, the radius of described half slot is 2.5-3.5mm, described head rod, described second connecting rod, described the 3rd connecting rod, described the 4th connecting rod width be 6-8mm, highly be 28-32mm, described head rod to the distance of described second connecting rod is 40mm, and the distance between two described the 3rd connecting rods is 30mm.

The shape of described second cavity and the shape of described actuator are complementary, the apical grafting of both sides up and down of described actuator has the actuator back-up block, described actuator back-up block is fixedly installed on the described knife rest, described knife rest is provided with the screwed hole that is communicated with described second cavity, be bolted with in the described screwed hole and hold out against screw, the described screw apical grafting that holds out against is on the rearward end of described actuator.

Be set with the sensor locating piece on the described knife rest, described displacement transducer is fixedly installed on the described sensor locating piece, the leading section of described cutter holder holder is provided with U type groove, cutter passes described cutter holder and stretches in the described U type groove, and described metallic rod vertically is fixedly installed on the described U type groove.

The upper surface of described knife rest is set with upper cover plate, and described sensor locating piece is fixedly installed on the described upper cover plate, and the lower surface of described knife rest is set with lower cover.

Described actuator is a piezoelectric ceramic actuator, and described spindle encoder is the high accuracy rotary encoder, and described displacement transducer is a high accuracy displacement sensor.

A kind of control method to described non-round cutting device, described controller adopts the immune control method based on the immune response theoretical model, wherein certain external disturbance of system is defined as antigen, the control output of this interference of removing that described controller response external interference is produced is defined as antibody, and the pass between described antigen and the described antibody is:

$u\left(k\right)=\frac{{e\left(k\right)}^2}{{\mathrm{\θ}}^2+e{\left(k\right)}^2}-K_S\·\{1-e^{-\frac{{\left[\mathrm{\Δu}(k-d)\right]}^2}{a}}\}\·e\left(k\right)$

Wherein: e (k) represents the antigen of certain sampling instant, when being machining according to the on-circular cross-section data of workpiece determine in the fix a cutting tool displacement of needs feeding of each anglec of rotation of main shaft, the antibody of the corresponding sampling instant of u (k) expression, it is the control output signal of controller, θ is the codomain constant, the degree that T type immunocyte excites antibody to produce when reflecting the invasion of antigen type in this model and antigen, K _SScale factor for this model, the inhibitory action that the concentration difference antagonist of expression antigen and antibody produces, concentration difference suppresses the effect size that antibody produces in Δ u (k-d)=u (k-d)-immune model of u (k-d-1) expression, wherein d represents the concentration difference of antibody, a represents AC difference constant, value is a ∈ (0,1).

The operation principle of this immune control method is in the immune response theoretical model, and antigen is regarded as certain external disturbance of system, and antibody then is considered to be controller response antigen and the control output of this interference of removing that produces.Immune response is a kind of mechanism of exempting from service based on T type immunocyte feedback regulation effect, effect at the different phase T of immune response type immunocyte is different, detailed process is the initial stage in immune response, antigen concentration is big and AC is little, T type immunocyte just excites production of antibodies, antibody is removed antigen gradually, and response process is promoted; In the later stage of immune response, antigen concentration is little and AC is big, T type immunocyte just suppresses production of antibodies, response process is suppressed, to guarantee immune stability, in the latter stage of immune response, antigen concentration and AC are all very little, reach the stabilization sub stage of immunity, immune response finishes.

Compared with prior art, advantage of the present invention is owing to be provided with flexure hinge mechanism in knife rest, and flexure hinge mechanism comprises two parallelogram elastic mechanisms along the center line symmetry, use two parallel-crank mechanisms and eliminate the principle of the additional displacement on the non-direction of feed, make flexure hinge mechanism as the straight-line displacement enlarger, thereby have and do not have the machinery friction, no backlass, advantages such as ultrahigh resolution, make knife rest have microposition function and precision cutting vibration control function, realize little feed motion of cutter in the non-round precision cutting system, and make knife rest can realize the microposition function of radially fixing a cutting tool simultaneously, can effectively control workpiece radially and the cutting vibration on the tangential both direction, obviously improved the turning accuracy of non-circular cutting, realize that lathe spindle is in the range of speeds of 2000～3000r/min, workpiece cross section ovality is under the situation of 1mm, and tool's positioning accuracy is less than 10 μ m; In addition; the shape of second cavity and the shape of actuator are complementary; and the apical grafting of both sides up and down of actuator has the actuator back-up block; can prevent in the course of work of knife rest; actuator produces and rocks, thereby influences turning accuracy, and is respectively arranged with cover plate in the upper and lower surface of knife rest; can protect knife rest not to be damaged, can prevent also that simultaneously the turning powder from falling in the knife rest.

Description of drawings

Fig. 1 is an overall structure schematic perspective view of the present invention;

Fig. 2 is a fundamental diagram of the present invention;

Fig. 3 is the front view of knife rest of the present invention;

Fig. 4 is the cutaway view of A-A among Fig. 3.

The specific embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

Embodiment one: as shown in the figure, a kind of non-round cutting device of numerically controlled lathe, comprise knife rest 4, be fixed with the cutter holder 10 of cutter 8, high accuracy displacement sensor 2, high accuracy rotary encoder 1, piezoelectric ceramic actuator 7 and controller 3, high accuracy rotary encoder 1 and high accuracy displacement sensor 2 all are electrically connected with controller 3, controller 3 is electrically connected with piezoelectric ceramic actuator 7, high accuracy rotary encoder 1 is arranged on the spindle motor of numerically controlled lathe, the upper surface of knife rest 4 is set with upper cover plate 51, the lower surface of knife rest 4 is set with lower cover 52, knife rest 4 is provided with first cavity 41 and second cavity 42 that is interconnected, be provided with flexible hinge structure 9 in first cavity 41, flexible hinge structure 9 comprises back seat 91 and cutter holder holder 92, be provided with two parallelogram elastic mechanisms between back seat 91 and the cutter holder holder 92 along the center line symmetry, the parallelogram elastic mechanism comprises head rod 94 longitudinally, second connecting rod 95 and two the 3rd horizontal connecting rods 96, head rod 94 is connected by horizontal the 4th connecting rod 97 one with cutter holder holder 92, second connecting rod 95 is connected with back seat 91 one, wherein one the 3rd connecting rod 96 is connected with knife rest 4 one, the junction of the 4th connecting rod 97 and cutter holder holder 92, the junction of the 4th connecting rod 97 and head rod 94, the junction of head rod 94 and two the 3rd connecting rods 96, the junction of two the 3rd connecting rods 96 and second connecting rod 95, second connecting rod 95 and the junction of back seat 91 be provided with two back to half slot 98, the radius R of half slot 98 is 2.5mm, head rod 94, second connecting rod 95, the 3rd connecting rod 96, the 4th connecting rod 97 4 width D be 6mm, height H is 28mm, the distance L of head rod 94 to second connecting rods 95 is 40mm, distance W between two the 3rd connecting rods 96 is 30mm, cutter holder 10 is fixedly installed on the cutter holder holder 92 by screw, be set with sensor locating piece 21 on the upper cover plate 51, high accuracy displacement sensor 2 is fixedly installed on the sensor locating piece 21, the leading section of cutter holder holder 92 is provided with U type groove 99, cutter 8 passes cutter holder 10 and stretches in the U type groove 99, be set with longitudinally the metallic rod of responding to mutually with high accuracy displacement sensor 2 22 in the U type groove 99, piezoelectric ceramic actuator 7 is arranged in second cavity 42, the shape of the shape of second cavity 42 and piezoelectric ceramic actuator 7 is complementary, the apical grafting of both sides up and down of piezoelectric ceramic actuator 7 has actuator back-up block 6, actuator back-up block 6 is fixedly installed on the knife rest 4 by screw, knife rest 4 is provided with the screwed hole 43 that is communicated with second cavity 42, be bolted with in the screwed hole 43 and hold out against screw 44, hold out against screw 44 apical graftings on the rearward end of piezoelectric ceramic actuator 7, the leading section apical grafting of piezoelectric ceramic actuator 7 is on the rear end face of back seat 91.

In the foregoing description, controller has adopted a kind of immune control method based on the immune response theoretical model, wherein certain external disturbance of system is defined as antigen, the control output of this interference of removing that the interference of controller response external is produced is defined as antibody, and the pass between antigen and the antibody is:

$u\left(k\right)=\frac{{e\left(k\right)}^2}{{\mathrm{\θ}}^2+e{\left(k\right)}^2}-K_S\·\{1-e^{-\frac{{\left[\mathrm{\Δu}(k-d)\right]}^2}{a}}\}\·e\left(k\right)$

Wherein: e (k) represents the antigen of certain sampling instant, when being machining according to the on-circular cross-section data of workpiece determine in the fix a cutting tool displacement of needs feeding of each anglec of rotation of main shaft, the antibody of the corresponding sampling instant of u (k) expression, it is the control output signal of controller, θ is the codomain constant, the degree that T type immunocyte excites antibody to produce when reflecting the invasion of antigen type in this model and antigen, K _SScale factor for this model, the inhibitory action that the concentration difference antagonist of expression antigen and antibody produces, concentration difference suppresses the effect size that antibody produces in Δ u (k-d)=u (k-d)-immune model of u (k-d-1) expression, wherein d represents the concentration difference of antibody, a represents AC difference constant, value is a ∈ (0,1).

The operation principle of this immune control method is in the immune response theoretical model, and antigen is regarded as certain external disturbance of system, and antibody then is considered to be controller response antigen and the control output of this interference of removing that produces.Immune response is a kind of mechanism of exempting from service based on T type immunocyte feedback regulation effect, effect at the different phase T of immune response type immunocyte is different, detailed process is the initial stage in immune response, antigen concentration is big and AC is little, T type immunocyte just excites production of antibodies, antibody is removed antigen gradually, and response process is promoted; In the later stage of immune response, antigen concentration is little and AC is big, T type immunocyte just suppresses production of antibodies, response process is suppressed, to guarantee immune stability, in the latter stage of immune response, antigen concentration and AC are all very little, reach the stabilization sub stage of immunity, immune response finishes.

Embodiment two: other structure is with embodiment one, difference is in the parallelogram elastic mechanism, the radius R of half slot 98 is 3mm, head rod 94, second connecting rod 95, the 3rd connecting rod 96, the 4th connecting rod 97 4 width D be 7mm, height H is 30mm, the distance L of head rod 94 to second connecting rods 95 is 40mm, and the distance W between two the 3rd connecting rods 96 is 30mm.

Embodiment three: other structure is with embodiment one, difference is in the parallelogram elastic mechanism, the radius R of half slot 98 is 3.5mm, head rod 94, second connecting rod 95, the 3rd connecting rod 96, the 4th connecting rod 97 4 width D be 8mm, height H is 32mm, the distance L of head rod 94 to second connecting rods 95 is 40mm, and the distance W between two the 3rd connecting rods 96 is 30mm.

Claims (7)

1, a kind of non-round cutting device of numerically controlled lathe, comprise knife rest, be fixed with the cutter holder of cutter, displacement transducer, spindle encoder, actuator and controller, described spindle encoder is arranged on the spindle motor of numerically controlled lathe, described displacement transducer is fixedly installed on the described knife rest, it is characterized in that described knife rest is provided with first cavity and second cavity that is interconnected, be wholely set the flexible hinge structure in described first cavity, the leading section of described flexible hinge structure has been wholely set the cutter holder holder, described cutter holder is fixedly installed on the described cutter holder holder, be set with the metallic rod of responding to mutually with described displacement transducer on the described cutter holder holder, described actuator is arranged in described second cavity, described flexible hinge structure comprises back seat, the leading section apical grafting of described actuator is on the rear end face of described back seat, be wholely set two parallelogram elastic mechanisms between described back seat and the described cutter holder holder along the center line symmetry, described spindle encoder and described displacement transducer all are electrically connected with described controller, and described controller is electrically connected with described actuator.

2, the non-round cutting device of a kind of numerically controlled lathe as claimed in claim 1, it is characterized in that described parallelogram elastic mechanism comprises head rod longitudinally, second connecting rod and two the 3rd horizontal connecting rods, described head rod is connected by the 4th horizontal connecting rod one with described cutter holder holder, described second connecting rod is connected with described back seat one, described the 3rd connecting rod is connected with described knife rest one, the junction of described the 4th connecting rod and described cutter holder holder, the junction of described the 4th connecting rod and described head rod, the junction of described head rod and described the 3rd connecting rod, the junction of described the 3rd connecting rod and described second connecting rod, described second connecting rod and the junction of described back seat be provided with two back to half slot, the radius of described half slot is 2.5-3.5mm, described head rod, described second connecting rod, described the 3rd connecting rod, the width of described the 4th connecting rod is 6-8mm, highly be 28-32mm, described head rod to the distance of described second connecting rod is 40mm, and the distance between two described the 3rd connecting rods is 30mm.

3, the non-round cutting device of a kind of numerically controlled lathe as claimed in claim 1, it is characterized in that the shape of described second cavity and the shape of described actuator are complementary, the apical grafting of both sides up and down of described actuator has the actuator back-up block, described actuator back-up block is fixedly installed on the described knife rest, described knife rest is provided with the screwed hole that is communicated with described second cavity, be bolted with in the described screwed hole and hold out against screw, the described screw apical grafting that holds out against is on the rearward end of described actuator.

4, the non-round cutting device of a kind of numerically controlled lathe as claimed in claim 1, it is characterized in that being set with on the described knife rest sensor locating piece, described displacement transducer is fixedly installed on the described sensor locating piece, the leading section of described cutter holder holder is provided with U type groove, cutter passes described cutter holder and stretches in the described U type groove, and described metallic rod vertically is fixedly installed on the described U type groove.

5, the non-round cutting device of a kind of numerically controlled lathe as claimed in claim 4, the upper surface that it is characterized in that described knife rest is set with upper cover plate, described sensor locating piece is fixedly installed on the described upper cover plate, and the lower surface of described knife rest is set with lower cover.

6, the non-round cutting device of a kind of numerically controlled lathe as claimed in claim 1 is characterized in that described actuator is a piezoelectric ceramic actuator, and described spindle encoder is the high accuracy rotary encoder, and described displacement transducer is a high accuracy displacement sensor.

7, a kind of control method to the described non-round cutting device of claim 1, it is characterized in that described controller adopts the immune control method based on the immune response theoretical model, wherein certain external disturbance of system is defined as antigen, the control output of this interference of removing that described controller response external interference is produced is defined as antibody, and the pass between described antigen and the described antibody is:

$u\left(k\right)=\frac{e{\left(k\right)}^2}{{\mathrm{\θ}}^2+e{\left(k\right)}^2}-K_S\·\{1-e^{-\frac{{\left[\mathrm{\Δu}(k-d)\right]}^2}{a}}\}\·e\left(k\right)$

Wherein: e (k) represents the antigen of certain sampling instant, when being machining according to the on-circular cross-section data of workpiece determine in the fix a cutting tool displacement of needs feeding of each anglec of rotation of main shaft, the antibody of the corresponding sampling instant of u (k) expression, it is the control output signal of controller, θ is the codomain constant, the degree that T type immunocyte excites antibody to produce when reflecting the invasion of antigen type in this model and antigen, K _SScale factor for this model, the inhibitory action that the concentration difference antagonist of expression antigen and antibody produces, concentration difference suppresses the effect size that antibody produces in Δ u (k-d)=u (k-d)-immune model of u (k-d-1) expression, wherein d represents the concentration difference of antibody, a represents AC difference constant, value is a ∈ (0,1).

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