JPH06254745A - Spring machining method and device - Google Patents

Abstract

PURPOSE:To establish a method wherein spring machining is automatically and high precisely applied to the surface to be machined of a work, and a device and a manufacturing reference for a spring machining tool applicable to execution of the method. CONSTITUTION:In a process where spring machining is effected by a spring machining tool 16, displacement of the cutting edge of a spring cutting blade 22 during resilient deformation centering around deformation fulcrum F responding to a machining reaction force is hourly detected. According to a detected result, machining command data of spring machine for a work are corrected by a spring machining control device 32 and automatically stable cutting operation is progressed until a machining size attains a target value and high precise spring machining is achieved. Further, the deformation fulcrum F of a spring machining tool is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hail processing method and apparatus capable of automatically and accurately performing a hail processing of a work, and to an improved structure of a hail processing tool used for the hail processing.

[0002]

2. Description of the Related Art Recently, in addition to a flat surface to be machined on a work such as a die, not only a linear groove but also a grooved surface along a closed curve or a machined surface including a downward slope surface or a raised medium-high curved surface Alternatively, a proposal has already been made to apply the hail processing even in the case of a complicated processed surface including a hollow medium-low surface. The hail processing tool used for this hail processing is elastically deformed as a cutting tool that is attached to a tool holding shaft of a machine tool having a C-axis that rotates around the Z-axis and cuts the work surface of a workpiece. A hail bite type cutting tool having a slit that forms a fulcrum in the upper region of the cutting blade is used. That is, this hail bite type cutting tool has a holder having an axis coincident with the axis of the C axis, and a hail cutting of a desired shape on a mounting surface of a cutting blade formed as a plane including the axis at the tip of the holder. The blade is fixed by a predetermined fixing means, and the elastic deformation fulcrum described above is arranged in the front region of the cutting blade mounting surface when viewed in the cutting progress direction, thereby elastically absorbing the cutting reaction force, thereby cutting. The machining reaction force is controlled within a certain fluctuation, and the cutting operation is advanced by advancing the hail cutting blade relative to the workpiece along a predetermined trajectory while preventing galling and biting. The same cutting tool as the hail bite type has already been proposed and provided, for example, in Japanese Patent Application No. 3-74976 filed by the present applicant.

[0003]

However, in the process of performing the hail processing of the workpiece using the above-mentioned hail bite type cutting tool, the holder of the tool is centered on the elastic deformation fulcrum according to the cutting processing reaction force. Since the cutting edge of the hail cutting blade is displaced due to the elastic deformation, the substantial depth of cut into the work becomes unknown. For this reason, in the process of performing the hail processing of the workpiece to the target dimension value, it is necessary for the operator to sequentially measure the working depth and rework the insufficient cutting amount to perform a correction process with human intervention. In addition, there is a problem that the processing efficiency cannot be sufficiently improved.

Further, the above-mentioned displacement of the cutting edge of the hail cutting blade causes a delay in the cutting edge position even in the feeding direction of the cutting tool, and in the processing of a curved groove or the like, the cutting edge position on the work surface is controlled. There is a case where there is a deviation in synchronism between the C-axis rotation control and the C-axis rotation control, which affects the machining accuracy.

Further, when an unpredictable situation such as an overload that cannot be absorbed by elastic deformation is applied to the cutting blade of the hail processing tool during the hail processing, the occurrence thereof is promptly detected. However, there is a disadvantage that the holder and cutting blade of the hail processing tool are ultimately damaged because the function of feeding back to the machine side is not yet provided.

Therefore, a main object of the present invention is to eliminate the problems associated with the conventional hail processing described above. Another object of the present invention is to provide a hail processing method and apparatus capable of automating the hail processing of a workpiece, improving the processing efficiency, and improving the accuracy of the hail processing according to a processing program. .

Still another object of the present invention is to further improve the structure of the hail processing tool.

[0008]

In order to achieve the above-mentioned object of the present invention, the present invention provides a tool for cutting a hail, in particular, a cutting blade associated with elastic deformation about a deformation fulcrum of its holder, that is, a hail bite. Measuring means for constantly measuring the displacement of the cutting edge or the displacement data etc. of the member provided so as to be displaced in response thereto is provided, and the cutting direction and cutting feed of the hail cutting tool are determined from the displacement data of the cutting edge obtained by this measuring means. The theoretical blade edge position in the direction is calculated, and the machining command value according to the machining program is automatically corrected by the correction means based on the difference between the blade edge position thus obtained and the target blade edge position according to the machining program. By controlling the cutting action of the hail processing tool according to the processing command value,
It aims at automation and high precision of hail processing.

That is, according to the present invention, in a hail processing method using a hail processing tool comprising a holder elastically deformable about a deformation fulcrum and a hail cutting blade attached to the holder, the hail processing is performed. During the cutting process of the work by the tool, the cutting edge displacement of the hail cutting blade due to the elastic deformation of the hail processing tool around the deformation fulcrum is detected, and the actual work processing for the target machining data of the work from the detection result. There is provided a hail processing method in which a difference value of data is obtained, a processing command of an NC program for processing a work is corrected based on the difference value, and a hail processing of a work is performed according to the corrected processing command.

Further, according to the present invention, a hail processing tool including a holder mounted on a tool holding shaft of a machine and elastically deformable around a deformation fulcrum, and a hail cutting blade attached to the holder is used. In a hail processing apparatus for performing a hail processing of a work, in a cutting process of the work, a cutting edge displacement detecting means for detecting a displacement of a cutting edge of a hail cutting blade due to elastic deformation centered on the deformation fulcrum of the cutting tool. And a correction unit that corrects a machining command according to the workpiece machining NC program of the machine based on the detection data of the cutting edge displacement detection unit, and via the machine feed mechanism according to the corrected machining command. A hail processing apparatus for controlling a hail processing tool is provided.

Further, according to the present invention, a hail processing tool comprising a holder mounted on a tool holding shaft of a machine and elastically deformable around a deformation fulcrum and a hail cutting blade attached to the holder is used. In a hail processing apparatus for performing a hail processing of a work, a storage means for storing the position data of the deformation fulcrum of the hail processing tool obtained in advance and the elastic deformation centered on the deformation fulcrum of the hail processing tool. Displacement measuring means for measuring predetermined displacement data corresponding to the displacement of the cutting edge of the hail cutting blade, and position information stored in the storage means and displacement data measured by the displacement measuring means, the hail of the hail processing tool. Based on the computing means for obtaining the displacement amount of the cutting edge of the cutting blade based on a predetermined computing expression, and the workpiece machining NC plan of the machine based on the displacement amount of the cutting edge obtained by the computing device. Is configured by including a correction means for correcting the machining command according grams, and Hale processing apparatus for controlling the Hale machining s ingredients is provided via a mechanical feed mechanism according to a machining command corrected.

Further, according to the present invention, a shaft-shaped holder mounted on a tool-holding shaft of a machine and elastically deformable around a deformation fulcrum according to a processing reaction force at the time of hail processing of a work, and the shaft-shaped holder. In the hail processing tool including a hail cutting blade attached to the elastic deformation fulcrum position, the elastic deformation fulcrum position is disposed on the front side in the traveling direction of the hail processing with respect to the axis of the shaft-shaped holder, and the elastic deformation fulcrum and the hail are provided. The angle between the straight line connecting the center of the cutting edge of the cutting blade and the axis of the shaft-shaped holder is set in the range of 10 degrees or more and 55 degrees or less, and from the center of the cutting edge of the hail cutting blade to the elastic deformation fulcrum. There is provided a hail processing tool having a distance dimension configured such that the shaft-shaped holder has a length having a predetermined elastic coefficient.

[0013]

According to the above-described hail processing method and apparatus according to the present invention, the hail processing tool is composed of a holder which is elastically deformable about a deformation fulcrum and a hail cutting blade attached to the holder. In the process executed based on the machining command value according to the NC program, the cutting edge displacement of the hail cutting blade of the hail processing tool is automatically measured, and the cutting amount and the feed amount based on the machining command are calculated based on the measured value. Is automatically corrected until the target workpiece machining size is reached.
Since the hail processing automatically advances, highly accurate hail processing can be realized with high processing efficiency.

The hail cutting tool has a predetermined angular relationship and distance dimension with respect to the elastic deformation fulcrum provided on the shaft-shaped holder, the axis of the holder, and the center of the tip of the hail cutting blade mounted on the holder. Since it is possible to clearly determine the manufacturing conditions so as to have, it is possible to select and manufacture a tool shape that matches the hail processing conditions of the work.

The present invention will be described in more detail below with reference to the embodiments shown in the accompanying drawings.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the overall construction of an embodiment of an apparatus used for carrying out the hail processing method according to the present invention, and FIG. 2 is a hail used in the hail processing apparatus according to the present invention. FIG. 3 is a cross-sectional view showing the structure of the main part of the processing tool, and FIG. 3 is a measurement when the displacement of the cutting edge center of the hail processing tool according to the present invention is measured using an enlarged arm as a jig. 4 is a front view and a side view of a schematic mechanism for explaining the principle, and FIG. 4 is an analysis for determining the deformation fulcrum position of the hail processing tool according to the present invention and for obtaining the distance dimension between the deformation fulcrum and the center of the cutting edge. FIG. 5 is a partially enlarged view showing the tip portion of the same tool in an exaggerated manner for explaining the principle, and FIG. 5 is a schematic view showing various states of hail processing between a hail processing tool and a work according to the present invention. Fig. 6 and Fig. 6 show the above-mentioned various types of hail processing. FIG. 7 is an analysis diagram of a moment acting on the hail processing tool in FIG. 7, FIG. 7 is a blade edge displacement according to a change in an angle α formed between a straight line connecting a deformation fulcrum and a center of the blade edge of the hail processing tool according to the present invention and a tool axis line. It is the figure which made the graph the relationship with and based on calculation.

In the hail processing method according to the present invention, as described later in detail, the blade tip displacement of the hail processing tool is detected, and the processing command by the processing program for the hail processing is corrected based on the detection result. However, the hail processing steps of the work can be automatically advanced until the work reaches the target dimension value. In the following, first, the hail processing method according to the present invention is carried out. The configuration of the device will be described.

Now, referring to FIG. 1, the apparatus used for carrying out the hail processing method according to the present invention is a machine tool MC.
The tool holding shaft 12 (in FIG. 1, the latter shows that the latter is the former element) is provided with a hail processing tool 16 which is mounted via an appropriate arbor 14 or the like. This hail processing tool 16 has, for example, one slit 18 like the previously proposed hail processing tool, and has elastically deformable shaft-shaped holder 20 and coaxial holder 20 at the tip of the cutting blade. It is configured to have a hail cutting blade 22 that is detachably fixed to the mounting surface, and is formed as a so-called hail processing cutting tool that cuts the processing surface of the work W with the feeding movement of the cutting blade. The shaft-shaped holder 20 of the hail processing tool 16 has a central axis which is mounted so as to substantially coincide with the axis of the tool holding shaft 12 of the machine, and the slit 18 passes through the central axis and is laterally crossed. Since the tool holding shaft 12 is provided with the C-axis rotation about the same central axis, the hail cutting blade 22 can rotate the C-axis.

Here, the hail processing tool 16 according to the present invention
Further, according to the processing reaction force acting on the cutting edge of the hail cutting blade during the progress of the hail processing of the work W, the holder 20 is provided on the front side in the direction of the hail processing with respect to the axis of the axial holder 20.
Elastic deformation is performed as described above centering on the deformation fulcrum F inside or outside the blade to perform stable hail processing without cutting edge of the cutting blade. At this time, elastic deformation centered on the deformation fulcrum F is performed. It is provided with a configuration for detecting the displacement of the associated hail cutting blade 22.

That is, the hail processing tool 16 according to the present invention
Includes a detection arm 24 inserted into a through hole formed at the center of the shaft-shaped holder 20, and the lower end of the detection arm 24 penetrates the slit 18 and is integrally formed with the shaft-shaped holder 20 or screw-engaged. It is fixed by the structure, and the upper end is
It extends through the through hole of the coaxial holder 20 and projects into a recessed hole 14 a formed at the lower end of the arbor 14. Therefore, when the shaft-shaped holder 20 is elastically deformed, the upper end of the detection arm 24 is also displaced, and the arbor 1 near the upper end of the detection arm 24 is displaced.
The displacement of the upper end of the arm is detected by a displacement sensor 26 which is attached to the portion 4 and which is, for example, a proximity sensor. That is, the displacement of the cutting edge of the hail cutting blade 22 can be detected via the detection arm 24, and the detection arm 24 and the displacement sensor 26 constitute the cutting edge displacement detection means. .

It should be noted that the above displacement sensor 26 is used in the arbor 1.
4 is connected to a signal transmitter 28 attached to the No. 4 via an appropriate signal line, and a detection signal sent from this signal transmitter 28 is attached to the tool holding shaft 12 of the machine.
Is transmitted by wire or wirelessly as necessary, and is formed so that a detection signal can be further transmitted from the transmitter 30 to the outside. When the C-axis rotation of the tool holding shaft 12 of the above machine is indispensable from the viewpoint of hail processing, the transmitter / receivers 28, 3 are wirelessly connected
It is desirable to connect 0s and eliminate the occurrence of entanglement of signal lines.

The detection signal of the cutting edge displacement of the cutting blade 22 of the hail processing tool 16 detected by the displacement sensor 26 is sent to the hail processing control device 32 provided by the present invention. The hail processing control device 32 is configured to include a memory means 34, a calculation means 36, and a control means 38. The calculation means 36 is connected to a receiver 30 via an interface (not shown), and similarly controls. The means 38 are connected to a known NC device NC which controls the machine tool MC via an interface which is also not shown. Then, when the detection signal of the above-mentioned blade edge displacement is input to the calculation means 36, the calculation is performed using the known amount and the calculation formula, which will be described later, preset and stored in the memory means 34, and the hail processing tool 16 is performed. When the hail cutting tool 16 is elastically deformed around the deformation fulcrum F due to a processing reaction force during the hail processing, the cutting edge of the hail cutting blade 22 is in the feed direction of the hail processing and the cutting direction to the work W. The actual displacement amount data for each displacement is calculated, and the displacement amount data of the calculation result is sent to the control means 38.

At this time, the control means 38 controls the NC device NC.
From the machining instruction data based on the NC program of the hail machining, and a target value for hail machining of the workpiece to a desired machining dimension is fetched from the machining command data. Then, a difference value between the target value and the displacement amount data sent from the calculation means 36 is obtained, and the same difference value is sent again to the NC device NC as correction data for the machining command data. Therefore, the NC device NC controls the feeding operation and the like of the machine tool MC based on the corrected machining command data. As a result, the hail processing tool 16 mounted on the tool holding shaft 12 of the machine tool MC is configured to perform the hail processing according to the corrected machining command data.

The target value fetched from the above-mentioned machining command data is the hail cutting blade 2 of the hail cutting tool 16.
2 includes the required machining amount data seen in the cutting direction and the allowable displacement amount data in the feed direction of the hail machining,
Therefore, the remaining machining amount can be obtained from the difference value between the displacement amount data in the cutting direction sent from the computing means 36 and the former required machining amount data, and the difference between the displacement amount data in the feeding direction and the allowable displacement amount data in the latter. The limit data for determining whether the load applied to the hail cutting blade 22 exceeds a predetermined load value can be obtained from the value, and the correction data for the machining command data is created from the obtained difference value between the two. It is sent to the NC device NC.

The above-mentioned correction of the machining command data is
It is automatically repeated momentarily during the hail processing steps, and therefore, the cutting processing by the hail processing method for the work W automatically and continuously progresses toward the target processing dimension. Next, for the sake of convenience of explanation, referring to the principle diagram exaggerated from the actual view in the partially enlarged view of FIG. 2, the cutting edge of the hail processing tool 16 receives a processing reaction force and is elastic about the deformation fulcrum F. The principle of detecting the amount of displacement of the cutting edge that occurs when deformed will be described.

As is apparent from FIG. 2, in the present invention, the displacement amount of the cutting edge is detected by the displacement sensor 26 through the displacement amount of the arm 24 mounted inside the hail cutting tool 16. It is provided. That is, the upper end of the arm 24 projecting into the recess 14a of the arbor 14 is normally disposed at a position close to the detection tip of the displacement sensor 26, and the displacement sensor 26 receives the processing reaction force. The displacement sensor 26 is provided in advance so that when the processing tool 16 elastically deforms around the deformation center F, the upper end of the arm 24 is displaced in the direction away from the detection tip. The traveling direction of the hail processing is shown by an arrow H in FIG.

Now, as shown in the figure, the parameters necessary for detecting the blade edge displacement are determined as follows. (1) Distance dimension between the deformation fulcrum F of elastic deformation of the hail processing tool 16 and the center of detection at the upper end of the arm 24: L (2) Distance dimension from the center of the cutting edge of the hail cutting blade 22 to the deformation fulcrum F: l (3) When elastically deformed around the deformation fulcrum F, the displacement sensor 26 detects the detected center of the arm 24 when the center axis 16A of the hail processing tool 16 is displaced to the position of the centerline 16B. Displacement amount: δs (4) Displacement angle when the central axis 16A is displaced to the position of 16B: θ (5) Straight line connecting the cutting edge center of the hail cutting blade 22 and the deformation fulcrum F and the center of the hail processing tool 16 Angle formed by the axis 16A: α When the parameters are set as described above, the displacement angle θ of the central axis 16A of the hail processing tool 16 due to elastic deformation is
It is expressed by the following equation.

Θ = tan ⁻¹ (δs / L) (1) Therefore, if δs is the detected value and the distance dimension L is known data, the displacement angle θ is calculated from the above equation (1). Desired. Here, when the hail processing tools 16 are used, the position of the deformation center point F of the elastic deformation of each of the hail processing tools 16 is unknown. It can be calculated from the measured data.

That is, FIG. 3 shows an example in which an enlarged arm 50 which can measure the displacement of the hail processing tool 16 in a similar manner is used as the actual measurement jig. The expansion arm 50 has two arms 52 and 54 that are formed in an L-shape and are arranged orthogonally to each other.
4 is brought into contact with the front surface of the hail cutting blade 22 of the hail processing tool 16 so as to be mounted and set so that the displacement of the cutting blade 22 is reproduced on the enlarged arm 50, and the arm 52 is set in the feeding direction of the hail processing. Place it so that it extends to the rear side as seen in. When the hail processing of the hail processing tool 16 is advanced in such a state, the enlarged arm 50 is also changed to the arms 52 and 54 in FIG. 3A as the tool 16 receives the processing reaction force and is elastically deformed. Arm 5 from the original position shown
It is displaced to the positions abbreviated as 2'and 54 '(the actual displacement amount is only a displacement in micron units, but is exaggerated for convenience of explanation).

At this time, each arm 5 of the expanding arm 50
It goes without saying that at points 2 and 54, the intersection D of the two also displaces and moves to the position shown as point E. Then, in the original position of the expansion arm 50, the displacement detectors PU1, PU2, which are arranged at known dimension positions measured in advance from the intersection D of the arms 52, 54, and which are, for example, known electronic micrometer measuring devices or the like. 3 detectors of PU3 are provided,
Similar to the three displacement data of the arms 52 and 54 of the enlarged arm 50 displaced by the elastic deformation of the hail processing tool 16, that is, the displacement data of two points when the arm 52 is displaced to the position 52 ′. When a total of three displacement data including the displacement data of one point when 54 is displaced to the position 54 ′ is actually measured by the displacement detectors PU1, PU2, PU3, both arms 52, 54 of the expanding arm 50 orthogonal to each other in the original position. A linear equation representing each arm 52 ′, 54 ′ in the same coordinate system where X is the X axis and Z axis in the two-dimensional coordinate can be obtained from the measured data.

That is, in FIG. 4, two straight lines (A) and (B) expressed by the above-described straight line equation are obtained, and the deformation fulcrum of elastic deformation is calculated from the straight lines (A) and (B). The analytical principle diagram for geometrically obtaining the position of F and obtaining the distance l between the obtained deformation fulcrum F and the cutting edge is shown. Explaining with reference to FIG. 4, first, in the equations of the straight lines (A) and (B), the displacement angle θ when the point D is displaced to the point E around the deformation fulcrum F (the displacement angle θ in FIG. 2). , Which is basically the same value as), Z = −1 / tan θ · X + C (2) Z = tan θ × X + B (3)

On the other hand, when the distance between the deformation fulcrum F and the cutting edge of the hail cutting tool 16 is 1 and the angle α shown in FIG. 2 is introduced, the intersection D of the expansion arm 50 is displaced. The coordinate value E (a, b) of E becomes a = l [sin (α + θ) -sinα] ...... (4) b = l [cosα-cos (α + θ)] ...... (5) That is self-evident.

However, since the point E exists on the straight lines (A) and (B), if the values of the equations (4) and (5) are introduced into the equations (2) and (3), respectively, The coordinate values of points B and C where the straight lines (A) and (B) intersect the Z axis are obtained, respectively.
Here, the displacement of the cutting edge during actual cutting will be considered. Since the actual displacement angle θ is a very small amount, it is approximately considered that the cutting edge is not displaced in the Z-axis direction but only in the X-axis direction, and the intersection of the straight line (B) with the X-axis is X coordinate is X
The displacement amount in the axial direction is δx. Similarly, it is approximately considered that the cutting edge is not displaced in the X-axis direction but is displaced only in the Z-axis direction, and the Z coordinate of the intersection of the straight line (A) with the Z axis is defined as the displacement amount δz in the Z axis direction. To do. That is, in FIG. 4, it is considered that the cutting edge located at the point D when there is no load is displaced to the position indicated by the point D ′ during cutting, and the X coordinate value δx (displacement in the feeding direction) of the point D ′.
The Z coordinate value δz (displacement in the cutting direction) is defined by the following equation. δx = 1 (tan θ [cos α-cos (α + θ)] + sin (α + θ) -sin α] (6) δz = l [cos α-cos (α + θ) -tan θ [sin (α + θ) -sin α]] (7)

Referring to FIG. 4 in more detail, when the hail processing tools 16 are displaced about the deformation fulcrum F of elastic deformation, the displacement angle when the intersection D of the expansion arm 50 is displaced to the point E. θ is, after all, one arm 5 of the arm 50
4 (corresponding to the straight line B) is the same angle as the displaced displacement angle θ. Therefore, the fulcrum F exists geometrically on the circle passing through the three points D, E, and C in FIG.
Since the straight line connecting the points D and E corresponds to the arm 54, the intersection of the circle and the bisector of the straight line connecting the points D and E is the position of the deformation fulcrum F. It can be calculated geometrically.

However, the actual value of the displacement angle θ of the expanding arm 50 in this case is the value measured by the displacement detectors PU1 and PU2 when the arm 52 is displaced to the position indicated by the arm 52 ', that is, the straight line (A Since the value obtained as the gradient of) corresponds to the coefficient tan θ of the above equation (3), the displacement angle θ in this case can be obtained as an actual value as its tan ⁻ value.

Thus, by obtaining the actual value of the position of the deformation fulcrum F of elastic deformation, the distance l between the deformation fulcrum F and the cutting edge point of the hail cutting blade 22, that is, the actual value of the angle α can be obtained. Of. Therefore, when these actual values l and α are introduced into the equations (6) and (7), the blade edge displacement of the hail cutting blade 22 of the hail cutting tool 16, that is, the displacement δx in the feed direction and the displacement δz in the cutting direction of the hail processing. And can be obtained as a function of the angle θ.

Here, referring to the equation (1), the angle θ = tan ⁻¹ (δs / L) is established for a general displacement angle θ. Therefore, as a result of the position of the deformation fulcrum F of the elastic deformation of the one hail processing tool 16 being obviously as described above, the distance L is a distance dimension between the deformation fulcrum F and the center of the upper end of the detection arm 24. Since it can be calculated as, a known amount is obtained, and δs is obtained as a detection value of the displacement sensor 26 held by the arbor 14 in FIG.
The values of various displacement angles θ can be calculated for various δs. Therefore, the displacement angle θ thus calculated can be substituted into the equations (6) and (7) each time to calculate the blade edge displacement δx in the feed direction and the blade edge displacement δz in the cutting direction. .

Referring again to FIG. 1, since the displacement detection value δs of the arm 24 is input to the computing means 36 of the hail processing control device 32 via the transceivers 28 and 30, the memory means 34 is stored in advance. Equation (1) above,
(6), (7) and the position data of the deformation fulcrum F of elastic deformation obtained by actual measurement using the expansion arm 50, the distance L between the deformation fulcrum F and the upper end center position of the arm 24, the deformation fulcrum F and the hail. By storing known data such as the distance 1 from the center of the cutting edge of the cutting blade 22 and the like, the calculation means 36
Automatically executes the calculation, and the control means 38 obtains the difference value between the calculated value and the target value from the machining command to determine the NC device N.
The machining command data based on the C NC program can be corrected every moment.

Thus, the hail processing method and apparatus according to the present invention corrects the processing command data based on the processing program every moment during the hail processing of the work W,
Since the hail processing is repeatedly performed until the target work processing dimension is obtained, the hail processing progresses without any human intervention by the operator, and at the same time the processing efficiency can be improved by automation and the work can be performed at the same time. A target value based on the machining command data, a long edge displacement detecting arm 24, a displacement sensor 26, and the like are provided as compared with the case where a person advances the hail processing while measuring the cutting depth. The hail processing of the work is performed while finding the difference value with respect to the target processing dimension by the automatic calculation based on the highly accurate measurement data of the blade edge displacement through the measurement data obtained by once being enlarged by the blade edge displacement detecting means. Therefore, it is possible to achieve a remarkable improvement in processing accuracy.

The displacement data of the hail processing tool 16 in the feed direction is obtained by obtaining a C-axis rotational driving force from the tool holding shaft 12 of the machine to perform groove processing along a complicated trajectory path. In this case, the timing of the cutting edge position of the hail cutting blade 22 and the timing of applying the C-axis rotation are corrected by the displacement data in the feed direction obtained by the above calculation, so that the desired locus path can be accurately processed by the hail processing. Since the tool 16 can progress the hail processing while following the tool 16, it is possible to improve the accuracy of the hail processing including the C-axis rotation. Moreover, since the blade edge displacement in the feed direction varies depending on the load applied to the tip of the hail cutting blade 22, when the blade edge displacement reaches a predetermined allowable displacement value, the blade edge is overloaded. As a thing, the calculation means 3 of the hail processing control device 32
Based on the calculated value obtained from 6, it is also possible to perform an alarm process to issue an alarm signal when an overload condition occurs in the hail processing process and to warn the overload condition by lighting a lamp, sounding a buzzer, or the like. .

As described above, the hail processing tool 16 used for the hail processing of the work is mounted on the tool holding shaft 12 of the machine tool as shown in FIG. By moving 22 in the feeding direction, the hail processing is performed. Here, in the hail processing of the workpiece W, the hail cutting blade 2 receives the processing reaction force and is processed.
In the process of 2 performing the cutting action, a cutting action state in which the blade edge bites into the work W, a state in which an excessive biting force acts at the time of cutting, and the cutting edge simply processes the work W with a change in the machining reaction force. It is necessary to avoid a state where the cutting operation is not performed by moving so as to follow the surface. In other words, while the hail processing tool 16 is elastically deforming around the deformation fulcrum F while the hail processing proceeds, the elastic deformation must always occur so as to avoid the occurrence of the above-mentioned three states. It has to be. Therefore, the position of the deformation fulcrum F of elastic deformation of the hail processing tool 16 must be properly selected.

Here, when the cutting action step of the hail processing is examined in more detail, the hail cutting blade 22 of the hail processing tool 16 is pressed against the processing surface of the work W at the start of processing, and then, By feeding a proper amount of feed in the cutting direction and then feeding in the desired cutting feed direction, when performing cutting while generating chips from the machining surface of the work W, or when starting machining, Abut with an appropriate amount of cut on the end face,
In some cases, the cutting edge may be fed from the abutting state in the cutting feed direction to cause chips to be generated from the machined surface of the work W as well.

Therefore, when analyzing the working state of the working reaction force acting on the cutting edge of the hail cutting blade 22 in the cutting working process of these hail processing, it is necessary to analyze various working reaction force working states as shown in FIG. You can That is, FIG. 5 (a)
Indicates that the cutting edge of the hail cutting blade 22 is simply pressed against the machining surface of the workpiece W. In this state, the machining reaction force Fc
Has a reaction force Fp acting in the opposite direction to the blade pressing direction.

FIG. 5 (b) shows that the cutting edge of the hail cutting blade 22 is pressed against the processing surface of the work W, and even if cutting feed is applied, it does not generate chips and simply feeds in the feeding direction. That is, in other words, the cutting is not substantially performed, and the workpiece simply slides along the working surface. In this state, the working reaction force Fc is the component Fp and the frictional force in the direction opposite to the pressing direction. Ff (= μ · Fp, μ: friction coefficient)
It acts diagonally as the resultant force (operating angle θ
a).

FIG. 5 (c) shows a state in which the hail cutting blade 22 advances a normal cutting state while producing chips without slipping on the working surface of the work W. At this time,
The processing reaction force acting from the processing surface of the work W is shown in FIG.
Unlike the case of moving along the machining surface as shown in (b), a large force is generated, and a frictional force is generated between the workpiece W and the machining surface as the hail cutting blade 22 is fed. Fc acts diagonally (the action angle θa is large).

Here, referring to FIG. 6, generally, in the cutting state in which the processing reaction force Fc acts on the cutting edge of the hail cutting blade 22 at the working angle θa, the holder 20 of the hail processing tool 16 is generally used.
Shows the case where elastic deformation is performed around the deformation fulcrum F. At this time, as in FIG. 2, the distance between the deformation fulcrum F and the center of the cutting edge of the hail cutting blade 22 is 1, and the angle formed by the line connecting the fulcrum F and the cutting edge center with respect to the axis of the tool 16 (deformation center angle) Is α. Considering the moment M when the processing reaction force Fc acts on the cutting edge in this state, the following formula is established.

M = Fc · l · sin (α + θa) (8) This equation (8) is applied to each of the above-described FIGS. 5 (a) to 5 (c) to find the acting moment. Moment in the state of 5 (a) Ma = Fc · l · sin α (9), θ
a = 0.

Moment Mb = Fc in the state of FIG. 5 (b)
.L.sin (α + θa) (10), θa = θf (
θf: friction angle). Moment M in the state of FIG. 5 (c)
c = Fc · l · sin (α + θa) (11)

That is, considering the moments Ma, Mb and Mc with respect to the change of the deformation center angle α, if the deformation center angle α is large in the pressing state of FIG. 5A, (9) The moment Ma is generated from the equation, and the hail cutting blade 22 elastically deforms together with the shaft-shaped holder 20 to soften the impact. However, when α approaches a zero value infinitely, the moment Ma approaches a zero value. In other words, the processing reaction force Fc causes excessive cutting bite as the pressing force increases, and the reaction force in the opposite direction is applied to the hail cutting blade 22 as it is, so that the blade has a large reaction force Fc. There is a risk of damage when the limit is exceeded. That is, the condition is that the deformation center angle α has an appropriate angle larger than 0 value.

Experiments were carried out on the shaft-shaped holder 20 equipped with the hail cutting blades 22 at various deformation center angles α, and α was at least greater than 10 °, preferably 15 ° or more. It turned out to be favorable.
Further, in order to generate the moment Ma and elastically deform, it is an essential condition to have the arm 1 having an appropriate length from the equation (9).

Next, considering the profile sliding state in FIG. 5B, generally, the friction angle θa by the hail cutting blade 22 is considered.
= Θf has been experimentally confirmed to be in the range of 10 ° to 12 °. Therefore, if the deformation center angle α is on the front side in the feed direction of the tool with respect to the axis of the hail processing tool 16, A moment Mb is generated even in the case of a zero value (α = 0), and if the hail processing tool 16 has an appropriate arm length l, the moment Mb is generated from the equation (10), so that the elastic deformation function is exerted. That is self-evident.

Similarly, in the case of FIG. 5C, the angle θa in the acting direction of the processing reaction force Fc is larger than that in the case of FIG. 5B, and the value of θa is about 50 °. Confirmed experimentally. Also in this case, the moment Mc is generated even if the deformation center angle α has a zero value (α = 0), so that the hail processing tool 16 can exhibit an elastic function. Considering the above states, the deformation angle α is at least 10 °.
It can be understood that the above is desirable.

Here, the upper limit of the deformation center angle α should be determined based on the blade edge displacement generated in the hail cutting blade 22 in accordance with the elastic deformation centered on the deformation fulcrum F described above. That is, the calculation was performed based on the equations (6) and (7) indicating the displacement δx in the feed direction and the displacement δz in the cutting direction described above.

As a result, as shown in FIG. 7, the deformation center F
The distance 1 between the center of the cutting edge and the center of the cutting edge was selected to be a practical value of 20 mm, and when the processing reaction force Fc was varied for various deformation center angles α, the displacement of the cutting edge was calculated. A graph was obtained in which the axis represents the amount of blade edge displacement in the cutting direction and the horizontal axis represents the amount of blade edge displacement in the feed direction.

From the graph shown in FIG. 7, it is found that the cutting edge displacement amount linearly changes as the working reaction force Fc increases for various deformation center angles α. However, the following was found regarding the blade edge displacement δx in the feed direction and the blade edge displacement δz in the cutting direction. That is, the relationship between the blade edge displacement δx in the feed direction and the blade edge displacement δz in the cutting direction is (a) Range of α> 45 °: δz / δx> 1. (B) When α = 45 °: δz / δx = 1. (C) Range of α <45 °: δz / δx <1.

In the case of the above (a), the hail processing tool 1
When the cutting edge 22 of No. 6 receives a processing reaction force Fc and a cutting edge displacement occurs due to elastic deformation around the deformation fulcrum F, the cutting edge displacement δz in the cutting direction exceeds the cutting edge displacement δx in the feed direction. Is shown. Therefore, the cutting blade 2
Since the blade edge displacement of No. 2 tends to be large in the cutting direction, the change in the machining reaction force Fc has a large effect on the blade edge displacement in the cutting direction, and the hail processing tends to proceed following the machining surface shape of the workpiece W. become. As a result, when hail processing is performed on the work surface where the uncut residue after cutting that has been rough-cut with a rotary cutting tool such as an end mill, the hail processing progresses following the uncut residue and the uncut residue gradually increases. Therefore, it cannot be said to be a preferable tendency.

In the case of the above (b), the hail processing tool 1
The hail cutting blade 22 of No. 6 shows that the blade edge displacement δz in the cutting direction and the blade edge displacement δx in the feed direction occur at substantially the same level when receiving the processing reaction force Fc. Therefore, the work-worked surface having the uncut portion also tends to remain at the same height as it is, which makes it unsuitable for applying the hail processing to the finishing of the work-worked surface.

In the case of (c) above, the hail processing tool 1
When the cutting edge 22 of No. 6 receives the processing reaction force Fc and the cutting edge displacement occurs due to the elastic deformation around the deformation fulcrum F, the cutting edge displacement δz in the cutting direction is less than the cutting edge displacement δx in the feed direction. Is shown. For this reason, when the hail processing is applied to the finish processing of the work having the uncut portion on the work surface, the uncut portion can be gradually reduced and a smooth finished surface can be obtained.

From the above consideration, in the hail processing tool used for practicing the hail processing method and apparatus according to the present invention, the position of the deformation fulcrum F of the elastic deformation is forward of the axis in the traveling direction of the hail processing. Along with that,
At that time, the distance l from the same point F to the center of the cutting edge has an arm length that generates an appropriate moment that enables elastic deformation, and the central angle α with respect to the deformation fulcrum F is substantially in terms of practicality. It was found that it is appropriate to be in the range of 10 ° or more and 55 ° or less.

As is apparent from the above description, the hail processing tools used for carrying out the hail processing method according to the present invention include a shaft-shaped holder mounted coaxially with the axis of the tool holding shaft of the machine tool. It consists of a hail cutting blade fixed to the cutting blade mounting surface of the same holder, and the shaft-shaped holder is elastically deformable around a predetermined deformation fulcrum, and the deformation fulcrum is in the feeding direction of the hail processing. In advance so that the displacement center angle α formed by the straight line connecting the fulcrum position and the center of the cutting edge of the hail cutting blade with the holder axis is selected and set within a predetermined range. Once manufactured, the work surface will be highly efficient and smooth, and
It turned out that it is possible to carry out hail processing on a highly accurate machined surface. In addition, the hail processing tools manufactured in this way can perform stable hail cutting action without chattering by effectively utilizing the elastic deformation characteristics that can elastically deform according to the processing reaction force. It becomes. In other words, it was possible to establish the manufacturing standards for the hail processing tools.

[0061]

As described above, the present invention has been described in detail based on the embodiments. However, the hail processing method and apparatus according to the present invention detect the blade edge displacement of the hail processing tool momentarily and according to the detected blade edge displacement. The machining command based on the machining program can be corrected to automatically and highly accurately advance the hail machining of the workpiece up to the target machining dimension.

Moreover, since a structure in which the hail processing tool used for carrying out this hail processing method exerts an optimum hail processing function has been found and the manufacturing standard thereof has been determined, the hail processing of the work is highly accurate and high in processing efficiency. It became possible to carry out under. Needless to say, the present invention can be variously modified and modified within the scope of the essential constituent elements described in the claims.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of an apparatus used for carrying out a hail processing method according to the present invention.

FIG. 2 is a cross-sectional view showing a main part structure of a hail processing tool used in the hail processing device according to the present invention.

3 (a) and 3 (b) are measurement principles when the displacement of the center of the cutting edge of the hail processing tool in the hail processing device according to the present invention is measured using an enlarged arm as a jig. 9A and 9B are a front view and a side view of a schematic mechanism for explaining FIG.

FIG. 4 is an exaggerated tip portion of the tool for explaining the analysis principle when determining the deformation fulcrum position of the hail processing tool according to the present invention and determining the distance dimension between the deformation fulcrum and the center of the cutting edge. FIG.

FIG. 5 is a schematic view showing various states of hail processing between a hail processing tool and a work according to the present invention.

FIG. 6 is an analysis diagram of a moment acting on each of the hail processing tools in the above various hail processing states.

FIG. 7 is a graph based on calculation of a relationship between a cutting edge displacement according to a change in an angle α formed by a straight line connecting a deformation fulcrum and a cutting edge center according to the present invention and a tool axis line. is there.

[Explanation of symbols]

 12 ... Machine tool holding shaft 14 ... Arbor 16 ... Hail processing tools 16A ... Axis 20 ... Axial holder 22 ... Hail cutting blade 24 ... Detecting arm 26 ... Displacement sensor 28 ... Transmitter 30 ... Receiver 32 ... Hail processing control Device 34 ... Memory means 36 ... Computing means 38 ... Control means F ... Deformation fulcrum

Claims (4)

[Claims] 1. A hail processing method using a hail cutting tool comprising a holder elastically deformable around a deformation fulcrum and a hail cutting blade attached to the holder, wherein a workpiece is cut by the hail cutting tool. In the process, the cutting edge displacement of the hail cutting blade due to the elastic deformation of the hail processing tool about the deformation fulcrum is detected, and the difference value of the actual work processing data with respect to the target work data of the work is obtained from the detection result. A hail machining method, wherein a machining command of an NC program for machining a work is corrected based on the value, and the hail machining of the work is performed according to the corrected machining command. 2. A hail cutting tool, which is mounted on a tool holding shaft of a machine and is elastically deformable around a deformation fulcrum, and a hail cutting blade attached to the holder, for hail processing of a work. In a hail processing device, a cutting edge displacement detecting means for detecting a displacement of a cutting edge of a hail cutting blade due to an elastic deformation centered on the deformation fulcrum of the hail processing tool during a cutting process of a work, and the cutting edge displacement detecting means. Correction means for correcting a machining command according to the workpiece machining NC program of the machine based on the detected data of the machine, and controlling the hail machining tools via the feed mechanism of the machine according to the corrected machining command. A hail processing device characterized by: 3. A hail processing tool is mounted on a tool holding shaft of a machine and elastically deformable about a deformation fulcrum, and a hail cutting tool attached to the holder is used for hail processing of a work. In the hail processing device, a storage means for storing in advance the position data of the deformation fulcrum of the hail processing tool, and the cutting edge displacement of the hail cutting blade due to elastic deformation centered on the deformation fulcrum of the hail processing tool. Displacement measuring means for measuring predetermined displacement data corresponding to, the displacement amount measured by the displacement measuring means and the position data stored in the storage means, the displacement amount of the cutting edge of the hail cutting blade of the hail processing tool. Based on a predetermined arithmetic expression, and a machining according to a workpiece machining NC program of the machine, based on the blade edge displacement amount obtained by the arithmetic means. Is configured by including a correction means for correcting the decree, the, via a mechanical feeding mechanism according to a machining command corrected Hale processing apparatus and controls the Hale working people immediately. 4. A shaft-shaped holder mounted on a tool-holding shaft of a machine and elastically deformable around a deformation fulcrum in response to a processing reaction force at the time of hail processing of a work, and a hail cutting blade attached to the shaft-shaped holder. In the hail processing tool consisting of, the elastic deformation fulcrum position is arranged on the front side in the traveling direction of the hail processing with respect to the axis of the shaft-shaped holder, and the elastic deformation fulcrum and the center of the cutting edge of the hail cutting blade. The angle formed by the connecting straight line and the axis of the shaft-shaped holder is set in the range of 10 degrees or more and 55 degrees or less, and the distance dimension from the center of the cutting edge of the hail cutting blade to the elastic deformation fulcrum is the axial shape. A hail processing tool characterized in that the holder is configured to have a length having a predetermined elastic coefficient.