CN1008561B - The reference data of cutter contact detection system - Google Patents

Abstract

The reference column 50 that is directly installed on the numerically-controlled machine saves the reference rings on chuck 36 end faces of outer round surface and card engaging workpiece usually that comprises reference datum, reference column 50 is made up of the elongated reference column element of side of being, cross section or circle, reference column elasticity is installed on the lathe, and workpiece is in calibration position relatively.With the effect of the piezoelectric element of electric signal oscillator coupling under, post 52 is done the longitudinal ultrasonic vibration.The frequency of accelerometer type is joined vibration transducer and is installed on the slide plate of lathe, when cutter 32 contacts with reference column as probe, is used for surveying the vibration of passing on the reference column.Draw the output signal of accelerometer by knife rest, by sending into numerical control unit after rotary coupler 74 integers, so that cutting workpiece is demarcated or measured.

Description

The reference data of cutter contact detection system

The present invention relates generally to the closed loop digital-control processing system, particularly relate to the cutter contact type probe that is used to measure.

Automatically precision processing technology just develops rapidly now, relies on manual system fully and makes way for the technology of coming processing parts with the universal numerical control system of processing basically.Although the cutting of material and other processing are carried out automatically in these automatic systems, also need a large amount of manual operationss, this mainly is in order to measure processing dimension and to do the cutter adjustment according to common NC cutting tool deviation.These hand dippings and cutter adjustment need be considered many factors, for example: the wearing and tearing of cutter; Reorientating and cutter changing of cutter; And since heating bear reason such as heavy duty and cause cutter, workpiece and the change in size of processing equipment own etc.

For instance, when carrying out most typical operation on numerically controlled lathe, some adjustment must manually be revised when beginning to process a certain workpiece by the operator as the cutter deviation.Before beginning processing, the operator must move on to cutter in the cutter positioning face, by the distance between manual measurement cutter and reference field, determines the tool position.This carries out with pad or similar material usually, and these are measured and constitute the artificial foundation of determining the cutter deviation.When lathe had a multiple-tool block, for each cutter, each kinematic axis of lathe all will carry out this operation respectively.Before cutting that special surface of the work is formalized at last, measure half-finished each surface size with hand-held measurer.This makes the desired correction of cutter when the operator can determine to cut at last.After final cutting is finished, also to check workpiece, see whether its surface size is consistent with desired size with hand-held measurer.

Above-mentioned manual each step all expends time in, and the time that it spent accounts on request size and produces the overwhelming majority that certain workpiece is taken time.This has just limited the productive capacity of lathe.Consider the machining period price of current lathe, milling machine (machining center), the reduction of any lathe ability all can bring significant impact at economic aspect.The more important thing is that all these manual operationss make process be subject to the influence of the maloperation of people own.

It is generally acknowledged, solve above-mentioned in-problem way and make hand dipping and hand cutting tool adjust robotization exactly, for example adopt computer-controlled digital control system.In such system, computing machine or away from numerical control device, or be contained on the numerical control device, as adopting microprocessor.Perhaps, computing power can also can be installed away from this in numerical control device.Whole procedure can be stored by a computer numerical control (CNC) system, call, edit (for example some program block of additions and deletions) and carry out deviation calculation and other computing by desired sequence, and not as numerical control (NC) system, import and be stored in the consecutive data block that resembles on the tape one class storage medium.

In finishing field developing stage, although fully automatic system also is not widely adopted, up to the present done a large amount of developments, great majority are only limited to some specific situation, promptly repeat single process operation.Now existing people is installing a contact triggering detector on the bed piece or on a transportable in case of necessity pivot arm, the position of cutter can be a benchmark with detector, and the position of cutter is revised when contacting by record cutter and detector.Difference according to precalculated position that observes and physical location determines the deviation compensation amount, and it is stored in the relevant storing apparatus of numerical control device, and departure has compensated the difference of predetermined contact position and actual contact position.

System and method with above-mentioned characteristic is published in United States Patent (USP) NO.4, and in 382,215, exercise question is authorized AllanRBarlow and WillianAHunter for " precision machined System and method for " 3 days Mays nineteen eighty-three, and has transferred the application's assignee.As disclosed in people's such as Barlow the patent, a contact be installed on toolframe trigger probe or sensitive element.Probe is that benchmark is demarcated with reference plane or reference field at first, is used for demarcating the cutter inductive probe afterwards, has only when contacting with the cutter inductive probe, and only at this moment the cutting edge of selected cutter is just demarcated.Initial correction value according to the determined cutter deviation of above operating result is stored in the numerical control device.After the processing beginning, demarcate the element senses probe once more, survey the finished surface of workpiece with it.The required correction of the last cutting of data decision that obtains thus.Afterwards, survey the face of tool, whether consistent to check the workpiece physical size with set-point.Although contact triggers the simple in structure of detector, must make specially at different detected object.Thisly can be easy to fragmentation at the probe that some speciality store has bought usually, and probe takies a tool position on the knife rest at least as commodity selling, turret lathe for example, moreover can not satisfy the usefulness of all cuttings.

In order to overcome the limitation that contact triggers detection system, technological process changes the device that processing work not only can have been processed simultaneously but also measure to cutter into.Such system is at United States Patent (USP) 4,428, delivers in 055, is entitled as " finishing tool contact detection system and method ", authorizes John RZurbrick and John Rkelley on January 24th, 1984, the assignee who also transfers the application simultaneously.Disclosed in the patent as people such as Zurbrick, adopt the mode of vibrating sensing to survey contacting of Tool in Cutting blade and several reference by location faces, cutting blade is that benchmark is demarcated with the reference surface under closed-loop control.The set-point of mensuration cutting blade and physical location is poor on each reference surface, produces the initial compensation of a tool position deviation automatically on each is axial, and deposits digitial controller in.After machine work, before final cutting finishes, survey a subjob at least, in this operating period, cutter has the function of cutter contact detector.Be installed in the vibration of the frequency dubbing vibration transmitters record cutter generation when the cutting blade of demarcating contacts as-machined workpiece surface on the capstan head.Determine suitable tool position deviation, send into numerical control device simultaneously, consistent to guarantee finally to cut size with required value.After the final cut, use the vibration induction mode, once more with the surface after the cutting blade detection processing of demarcating.Although this system has made significant improvement on technology,, can not reach two reference surface or two reference fields of special purpose machine tool when cutter itself during as gauge.

United States Patent (USP) 4,382,215 and 4,428,055 spy is used for reference at this.

Therefore, the purpose of this invention is to provide a kind of improving one's methods of part to be processed of measuring.The further purpose of invention is to being used in the improvement of the contact detection system in the closed loop digital-control processing system.Another purpose of invention is to improve the reference field device of cutter contact detection system.Another purpose of invention provides a kind of device, and it for example is applied in the reference rings in the numerically-controlled machine lathe spindle with reference field substituting group lead ring.

Say that briefly the present invention has realized above-mentioned and other purpose with form preferably.On numerically-controlled machine a prior selected cross sectional shape being installed is elongated ultrasonic vibration reference column, and making the distance of its center line apart from turning axle (or other known reference point) is given value, makes the reference column longitudinal axis perpendicular to workpiece.Not only,, measured processed workpiece with the vibration reference column as cutting element but also as the cutting tool of contact sonde.Reference column is preferably done extensional vibration.By being installed in frequency on the knife rest that cutter is housed, survey contacting of cutter and reference column, processing component surface with addition of velograph.The accelerometer output signal shows that cutter is contacted.These signals are delivered to the closed loop numerical control device by rotary coupler and shaping circuit.Because in the tool coordinate reference frame, the accurate position of vibration column reference plane is known, so in case cutter contacts with reference column, the position of tool surface also just becomes known.This makes that digital control system can be right, and for example, tool wear, change in size etc. is revised.In fact, the vibration reference field is as the tool surface calibration device.In case after demarcating, cutter just can be used for surveying surface of the work, survey and the contacting of surface of the work by being sent to " frictional vibration " on the accelerometer.By the relatively surface location in the coordinate system or the position of relative reference post one to one, determine the size of workpiece.

The present invention is limited by claim, cooperates the accompanying drawing of giving, the following explanation of reference the present invention may be better understood content.

Fig. 1 is a simplification front elevation that horizontal capstan head lathe is housed, and it has represented prior art, adopts rotatable knife rest, can make each cutter or detector enter Working position.

Fig. 2 is a simplification vertical view that horizontal capstan head lathe is housed shown in Figure 1, has reflected principal feature of the present invention among the figure.

Fig. 3 is the preferred embodiment figure of reference column of the present invention.

Fig. 4 has showed reference column assembly simplification front elevation, and the reference column assembly comprises reference surface shown in Figure 4 and the back-moving spring that is installed on Fig. 2 lathe.

Fig. 5 is an electric calcspar, has showed the electrical signal paths between the accelerometer that is installed on the knife rest shown in Figure 2 and the numerical control device shown in Figure 1.

Fig. 6 is for helping to understand the family curve that operation of the present invention provides.

With reference to accompanying drawing, particularly Fig. 1 is the simplification front elevation of a horizontal turret lathe processing unit (plant).A common turret lathe is along two orthogonal axis operations, and one is X-axis, and another is the Z axle, and X-axis is defined as the direction perpendicular to lathe bed, and the Z axle is consistent with the direction of lathe bed.As shown in the figure, the body of lathe bed comprises support 10, and two guide rails along Z-direction are arranged on the support 10, wherein one in the drawings reference number be 12.Being parallel to the Z axle is the center line 14 of lathe spindle 16.On guide rail 12, install one along Z-direction can be forward (near workpiece-Z), (leave the saddle or the big slide plate 18 of workpiece+Z) slide, big slide plate is along Z axle location, driven by common direct current positioning motor that leading screw (drawing among the figure) finishes backward.

In addition, slide plate 18 has a pair of cross slide way 20,22, has cross slide 24 not draw among the figure along X-axis running fix on the cross slide way, and the location of cross slide 24 on X-axis also drives leading screw by the direct current positioning motor and finish.Each motor or leading screw can be adorned a common rotary transformer or scrambler, so that the position of rotation of feedback signal indication counter element to be provided.These feedback signals represent slide plate 18 and slide plate 24 along its linear position on corresponding axis separately.In addition, can adopt suitable electricity or photoelectric encoder that the feedback signal of direct reflection slide plate 18 and cross slide 24 linear positions is provided.

Cross slide 24 drives knife rest 26, and a plurality of cutters seat 28 is arranged on knife rest 26, and a tool rest 30 can be installed in each seat.The capstan head 26 of device shown in Figure 1 can be installed six independently bite or contact sondes usually on cutter seat 28.By suitable transposition, promptly rotating turret 26, and each cutter or probe can be placed on the illustrated operating position.For simple and clear, knife rest shown in Figure 1 only has a tool rest 30 thereby has only expressed one cutter 29.In addition, shown in cutter 29 blade 31 is housed, the cutting blade 32 of blade 31 is over against workpiece.

Lathe body shown in Figure 1 also comprises a main shaft driving device and is positioned at the gear case 34 of one end.Rotary main shaft 16 stretches out from drive unit and gear case assembly 34, and main shaft 16 drives chuck 36, and one group of claw 38 that is used for card engaging workpiece 41 is housed on chuck.In addition, containing a crown of roll head 40 on the rotary main shaft 16 joins with chuck 36.The intersection point of plush copper 40 planes and main shaft 16 or center line 14 is decided to be original null position or initial point, that is to say that the operator of special purpose machine tool begins to determine that from original zero point machine tool component and tool position are so that carry out systems programming.And all program location all are referred to this initial point.The measuring system of lathe itself is calculated or is measured with the relative position to initial point all the time.The initial point of measuring system is located at the place away from main shaft plush copper and center line usually, because big slide plate 18 and cross slide are transportable.

The structure of chuck 36 in the prior art also contains a reference rings, has a pair of reference by location face or reference field perpendicular to X-axis and Z axle at least, and each reference plane position is known apart from the distance of initial point.The periphery 42 of chuck constitutes a reference surface among the figure, and chuck face 44 constitutes another reference surface.

Described in people's such as Zurbrick United States Patent (USP) 4,428,055, knife rest top is installed one and is determined good acoustic vibration transmitter 37 in advance, and it produces an electric signal and changes along with machinery or acoustic vibration.For example, when cutting blade 32 contacts with rotational workpieces 41, " frictional vibration " is sent to transmitter.Workpiece causes vibration with respect to the required quick relative motion of rotation generation of cutting blade.In order to survey, cutter 32 is the contact workpiece surface gently, and returns at once, makes that applying tries hard to keep holds minimum, avoids as-machined workpiece surface in exploration operation.In some cases, do not allow to leave a trace on the workpiece of processed mistake, in exploration operation, workpiece can be done reverse rotation, even like this, although the surface of the work of processed mistake also may cause this damage of damage not serious because of contacting with cutting blade.For this reason, in case of necessity, can Vib. 39 be housed on chuck 36, be suitable for the vibration of transmitting little amplitude when workpiece does not rotate.This vibration is sent on the cutter 32 by workpiece 41, is sent to transmitter 37 by cutter holder and the knife rest 26 that tool rest 30 is housed then.So the quick relative motion between Tool in Cutting sword and surface of the work realizes by Vib. caused small magnitude to-and-fro movement on workpiece, rather than realize by the rotation of workpiece.In detection process, workpiece does not rotate usually, just Vib. 39 work.

Label is that 46 device is numerical control (NC) system among Fig. 1.(being lathe) many different parts carry out electricity and cooperate in this system and the lathe, as direct current positioning motor, rotary transformer harmony transmitter or the like.Numerical control device 46 also comprises a ribbon feeder 48, and it is applicable to the numerical control program of storage processing work, and it represents different instructions with code form.For example: program can be used to rotating turret 26; Emit the required cooling medium of processing; Select main axis rotation direction and speed; By specific order mobile probe, cutter and other relevant operations.Tape can be stored some data, for example, needs the size that requires of processing work one side, the permission finish allowance of each size and some parameter, as: the workpiece that process, used cutter and the cutter that will use.

Numerical control device 46 preferably is equipped with a microprocessor, and it carries out the instruction that is stored on the tape, and microprocessor sends certain control signal influences tape order.Microprocessor is also handled so that calculation deviation is revised the various cutting operations of carrying out job sequence the data that various detections (as measuring) operation obtains.Above-mentioned some function can be carried out by remote control computer, for example at the central computer of a distribution digital control system, the data after handling is fed back to numerical control device 46,46 produce appropriate control signals subsequently.In this structure, computing power can be placed in the numerical control device 46.

The data that exploration operation obtains are handled by microprocessor from the data that the feedback data and the program itself of rotary transformer are loaded, and calculate above-mentioned error.The motor control signal that obtains after the data processing compares with the position feedback data that corresponding motor rotary transformer or other position feedback device are received.In closed-loop control system, the position of the difference control Tool in Cutting sword that two kinds of signals relatively obtain or the position of measuring sonde.Numerical control device 46 also can be used to calculate, show, print the physical size of workpiece, and the deviation of calculating and set-point, shows the finish allowance that allows.Numerical control device 46 can adopt commercial equipment, for example the Mark Century 2000 computer numerical control devices of the available General Electric Co. Limited of user.

The further comprehensive discussion of system of processing operation shown in Figure 1 can be consulted above-mentioned people's patents such as Zurbrick of quoting, U.S. Patent number 4,428,055, the subsidiary introduction utilizes cutter 29 to measure the idea of workpiece to be machined 41 as the cutter contact sonde in the literary composition, yet, for special purpose machine tool, when using cutter, can not reach two reference surface or two reference fields as gauge.

This just draws research of the present invention, and referring to Fig. 2, a vibration reference column assembly 50(who installs in the pedestal mode sees Fig. 3,4 for details), be suitable for providing at least one (but preferably two or more a plurality of) to can be used for the reference field of cutter contact detection system.We attempt with 42 and 44 reference rings surface structures among reference column assembly 50 replacement Fig. 1.Reference column assembly 50 is known with the position of center line 14, the longitudinal axis of reference column assembly 50 is preferably mutual vertical with workpiece 41, cutter 29, reference column has been determined a known accurate fixed reference position to cutter, and demarcates the tool position with it before contact workpiece.Clearly, reference column 50 can be installed in desired position in the lathe coordinate reference system, and importantly its basic side is accurately to fix.

In addition, with reference to figure 3 and 4, reference column assembly 50 is made up of elongated reference column member 52, and as shown, its cross section is a square, if desired, can be for example spirality, octagon or annular or the like of other suitable shape.Square assurance two planes are orthogonal, thereby guarantee that reference plane is parallel to the X-axis and the Z axle of lathe.Slender member 52 is done the longitudinal sound wave vibration under the exciting of one or a few piezoelectric element 54, preferably do ultrasonic vibration, and the excitation of piezoelectric element is by oscillator 56(Fig. 4 shown in Figure 4) realize that its frequency of operation is 50kHZ.Finish required electric coupling with suitable binding post 58 and 60.Piezoelectric element starting excites reference column 52, thus make its shown in vertical direction do before and after linear movement repeatedly.In addition, reference column 52 supports by dull and stereotyped 62, the strong point is a vibration nodal point on the reference column 52, three equally distributed mounting holes 64 are arranged on the flat board, so that flat board flexibly is fixed on the angle bracket 66, and carriage 66 is fixed on the bed piece, for example is fixed on the inside surface 68 of gear case shown in Figure 2 34.Yet when needing, angle bracket 66 can extend downwards and directly be fixed on to be adjusted on the guide rail 12.Under any circumstance, carriage is securely fixed on the lathe, and reference column 52 can be regarded the part of the lathe bed of installation component as.In addition, with reference to mast member 52 and three mounting spring 68 of dull and stereotyped 62 usefulness pad by matching with hole 64, elasticity is installed on the carriage 66, make cutter can ± X and ± the Z direction moves, even over travel also can not influence the integrality of the reference position of post.

Reference column assembly shown in Fig. 3,4 particularly ultrasonic vibration reference column 52 on being contained in knife rest 26 among Fig. 2 the accelerometer of label 72 work.When cutter 29 touches vertical vibration source reference post 52 as probe, detection is from the ultrasonic vibration of reference mast 52, and accelerometer can be any one model of store sales, for example, the design model is 1018 accelerometer on the market, just can finely satisfy requirement of the present invention.

As shown in Figure 5, accelerometer links to each other with a rotary coupler 74, make the electric signal output of accelerometer pass to numerical control device 46(Fig. 1), but, before sending into numerical control device 46, accelerometer signal is at first carried out shaping by amplifier and bandpass filter and recognizer, and the signal of sending into the shaping of numerical control device 46 has not had spurious signal, in addition as shown in Figure 5, in shaping circuit 76 and numerical control unit 46, also add appropriate signals treatment circuit 78.Accelerometer 72 preferably with the vibration frequency resonance of reference column 52, the effect that this can play raising sensitivity makes easier the measuring that contact on tool surface and reference column 52 surfaces.Vibration frequency can be decided by suitably selecting oscillator 56.As mentioned above, the big order of magnitude about 50kHZ.

During operation, make the cutter contact sonde, for example the cutter 29 of Fig. 2 detects contact up to accelerometer 72 by treatment circuit near reference column 52 and takes place.On contact position, the position at cutter place is accurately located, and writes down, is stored in the numerical control device 46.Then, cutter 29 is return, to rotational workpieces 41(Fig. 2) motion, experience " friction " activation signal opposite of appearance up to accelerometer 72 with cutting signal.As shown in Figure 6, cutter and workpiece friction produce a very low constant amplifying signal, and the signal that this signal produces when cutting, writing down with workpiece or measuring is different.By with the friction of workpiece, this position is recorded once more, stores, cutter is return.The difference of known reference position and workpiece contact point provides the necessary information of calculating workpiece size.This calculating is carried out with a kind of known method in numerical control device 46, as United States Patent (USP) 4,428, is narrated in 055.

The present invention has removed the rotation reference rings 36 on the main shaft shown in Figure 1 40.The advantage of the disposal route that the present invention proposes is many-sided, is different from the reference rings form, the place that reference column 52 can place all cutters to reach; Can carry out the demarcation of all directions.And, in case of necessity different operating point or cutter are adopted a plurality of reference columns.And because reference rings uses meeting to produce cut for a long time, the reference column of being introduced among the present invention guarantees to have long-term serviceable life, also have, before contact workpiece 41, by using cutter 32 contact vibration posts 52, have an opportunity the ultrasonator circuit is carried out deagnostic test, thereby avoided in case ultrasonic reception or other relevant circuit malfunction cause the mistake of workpiece to measure.If for a certain reason or circuit malfunction, make near the main shaft datum line and will cause serious scuffing and damage.In the program that computer numerical control is measured, usually only to measured workpiece or reference field among a small circle but be that the very important excess of stroke (programme as 0.1 by ").The excess of stroke that the plasticity of reference column will cushion cutter moves, and can not be damaged.But main shaft reference field scheme is not just accomplished this point.When cutter cross the excess of stroke apart from the time, can programme quits work Computerized digital control system (CNC), sends out a fault-signal to the operator.

As mentioned above, although the cross section of the reference column of introducing in the explanation is a rectangle, for different measurement direction of closing, can adopt the reference column of different cross section shape according to specific needs.For example when direction of closing be not during along X-axis, Z axle, can adopt an anistree shape reference column, can realize demarcating along 45 ° of directions and X, Z-direction.

Described above is illustrated embodiments among the present invention, for the skilled artisan in the art, makes improvements at an easy rate.For example, foregoing invention is to be used on the numerically controlled lathe, and clearly, for those skilled in the art, the present invention is not limited only to lathe, for requiring lathe and system of processing accurately, can adopt the present invention also therefrom to benefit.Thereby do not wish that the present invention only limits on several particular devices of above displaying.But wish all to correction of the present invention, change and modification all are included within the spirit and scope defined in the claim of the present invention.

Claims (20)

1, a kind of with the method for cutter contact detection with definite required size of workpiece to be machined, it may further comprise the steps:

The fixed datum device is located;

Vibration said reference face device;

Make to be installed in can contact with said reference face device on the machining system, and survey the vibration of therefrom sending by the machining tool that cutting tool is formed;

When touching said reference face device, determine the residing position of above-mentioned tool face;

Make this cutter do predetermined contacting, and survey both contacts with above-mentioned workpiece;

When touching above-mentioned workpiece, determine the position of this tool surface; And

Obtain the difference of twice contact position, thereby determine required size;

It is characterized in that the step of described positioning and fixing reference field device is that the turning axle that the fixed datum device is positioned to leave workpiece is had a segment mark set a distance.

2, in accordance with the method for claim 1, it is characterized in that this reference field device comprises a reference column, its orientation is perpendicular to the turning axle of workpiece.

3, in accordance with the method for claim 2, it is characterized in that detection steps when contact said reference face device and described workpiece comprises that usefulness is installed on the machine worker adding system accelerometer in the localities near described machining tool and surveys.

4, in accordance with the method for claim 3, it is characterized in that saidly making this cutter and workpiece make the predetermined step that contacts to comprise and make this cutter and workpiece carry out rubbing contact.

5, in accordance with the method for claim 4, the step that it is characterized in that the said reference field device of described vibration comprises the step of vibrating said reference column with the sound wave mode.

6, in accordance with the method for claim 5, it is characterized in that described step with the said reference column of acoustic vibration comprises that making said reference column make longitudinal ultrasonic vibrates.

7, in accordance with the method for claim 6, it is characterized in that said machining tool can move on two orthogonal axis.

8, in accordance with the method for claim 7, it is characterized in that said cutter comprises is contained in the cutting tool on the rotary knife rest on the lathe.

9, in accordance with the method for claim 1, it is characterized in that said machining system comprises a programmable digital-control processing system, the numerical control device in this system is applicable to according to selected job sequence and operates.

10, in accordance with the method for claim 9, it is characterized in that the described step of when said cutter contacts with described reference field device and contacts with described workpiece, determining the cutter position, also comprise the above-mentioned position quantity of storage, thereby therefrom obtain two positions amount difference, and determine the size that processing is required by described numerical control device.

11, be used in the reference coordinate system of lathe accurately setting the cutting tool surface location and be suitable for providing to numerical control unit the equipment of cutting tool position signalling, it comprises:

Benchmark reference plane device;

Cause the device of described reference plane device vibration;

Be positioned near said cutting tool, and be suitable for responding vibration that this cutting tool sends, with the sensor device of indicator signal that this vibration is provided;

Be used to locate this cutting tool with the cutting tool locating device that contact of realization cutting tool surface with described benchmark reference plane;

Be used to receive the device of vibration indication signal and cutting tool position signalling, when said contact takes place, produce said vibration indication signal, said cutting tool position signalling has been indicated the accurate position of tool surface;

It is characterized in that described benchmark reference plane device is to be positioned at the turning axle that leaves workpiece in the described reference coordinate system regularly to have on the known accurate position of a segment mark set a distance.

12, according to the described device of claim 11, it is characterized in that said reference plane forms by at least one right angle, be parallel to two orthogonal axis to guarantee the vibration reference field.

13, according to the described device of claim 12, it is characterized in that said reference plane is an elongate rod shape, its xsect is for to become vertical square with its longitudinal axis.

14,, it is characterized in that said sensor is an accelerometer according in the described device of claim 13.

15,, it is characterized in that the device that causes said reference field vibration comprises that at least one is contained in piezoelectric element and the oscillator that this piezoelectric element is excited with ultrasonic frequency on the reference field according to the described device of claim 14.

16,, it is characterized in that said reference field can do extensional vibration according to the described device of claim 15.

17,, it is characterized in that said accelerometer is with the ultrasonic action frequency resonance according to the described device of claim 15.

18, a kind of with the cutting tool on the lathe as measuring sonde, measure the method be installed in the workpiece to be machined size on the lathe, this method may further comprise the steps:

A., the reference field device is provided;

B. make described reference field device vibration;

Tool surface is contacted with reference field,, detect the generation of contact by pass to the vibration on the vibration transducer by described cutter;

D. according to detected contact among the step c, determine the surface location of cutter;

E. during workpiece motion s, certain that will determine workpiece size on cutting tool surface and the workpiece at this some place some contact, and detect according to the cutter frictional vibration that passes to vibration transducer by above-mentioned cutter and to contact generation;

F. by detected contact among the step e, decision is in the position of the surface of the work at contact point place;

G. determine the position of surface of the work with reference to the reference position in the reference coordinate system, and with this measuring as working size;

It is characterized in that described reference field device is installed in the turning axle that leaves workpiece in the machine coordinates reference system and has on the accurately known fixed position of a segment mark set a distance.

19, in accordance with the method for claim 18, it is characterized in that said workpiece rotates, and the reference position is exactly a turning axle.

20,, it is characterized in that making described reference plane to produce vibration, and vibration transducer is exactly an accelerometer with this ultrasonic frequency resonance with ultrasonic frequency according to the method described in the claim 18.

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