JPS63295160A - Measuring method for tool abrasion loss in machine tool - Google Patents

Abstract

PURPOSE:To prevent an error due to thermal displacement from occurring by moving a tool and a reference tool edge unused for machining up to an edge detecting device from a measuring reference position respectively before and after the machining, and finding an abrasion loss by means of subtraction between both travel differences. CONSTITUTION:The tool 3 attached to a tool rest 2 is moved up to a touch sensor 6 from a measuring reference position of a measuring reference point SP or the like before and after machining in a lathe 1, finding the travel values XE, XE', ZE and ZE'. And likewise, a reference tool edge 5 unused for the machining is moved up to the touch sensor 6 from the measuring reference position, finding the travel values XES, XES', ZES and ZES' as to the difference in addition, and this difference is subtracted from a travel difference of the tool 3, finding abrasion losses LX and LZ. Thus, even if time difference occurs in measuring action at a tool edge position, that is, thermal displacement occurs in a measuring system, the abrasion loss accurately measurable in the shape of eliminating the thermal displacement.

Description

Detailed Description of the Invention (a) Industrial Field of Application The present invention is a method for measuring tool wear in machine tools such as lathes, in which the amount of tool wear can be measured without the influence of thermal displacement. Concerning methods of measuring quantities.

(b), Conventional technology Conventionally, when measuring the amount of wear on a tool in a lathe, etc., the position of the cutting edge with zero wear is measured in advance, and after machining for a predetermined time, the position of the cutting edge of the tool is measured again. Measure and
The difference was taken as the amount of tool wear.

(C) 0 Problems to be Solved by the Invention However, with these methods, there is a time difference between measurement with zero wear and measurement after wear has occurred, so the heat generated in the measurement system during that time is Since the influence of displacement cannot be ignored, it is difficult to accurately determine the amount of tool wear.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a method for measuring the amount of tool wear in a machine tool, which can accurately determine the amount of tool wear while eliminating the influence of thermal displacement. It is.

(d) Means for solving the zero problem, that is, the present invention provides a cutting edge detection means (
6) and the amount of movement at that time (XE9, xgs'
.
Find the value obtained by subtracting the difference in the amount of movement of the reference cutting edge from the difference in
The requested value is configured to be the wear amount (ΔL 1ΔL ).

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description should not be limited to the descriptions in the drawings. The following r (el
The same applies to the column ``, action''.

(e) 0 effect With the above-described configuration, the present invention has the following advantages: the amount of movement of the reference cutting edge (5) before and after machining (x,...
, z, ,') becomes the thermal displacement amount of the measurement system, and the tool movement amount (X2.Xl,:' , Z!, Z,'
) (7) By subtracting the difference in the amount of movement of the reference cutting edge from the difference, the amount of tool wear that eliminates the influence of thermal displacement is obtained.

(f), Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a plan view showing the main parts of a lathe to which an embodiment of the method for measuring the amount of tool wear according to the present invention is applied, and FIG. 2 is a plan view showing an example of the method for measuring the position of the cutting edge.

As shown in FIG. 1, a lathe 1, which is a machine tool, is supported so as to be movable in the directions of arrows A and B, which are the Z-axis direction, and in the directions of arrows C, D, which are the X-axis directions perpendicular to the A1B direction. The tool rest 2 is supported so as to be rotatable in directions of arrows E and F around a pivot center CT. A plurality of tools 3 are provided on the tool rest 2, and in addition to the normal tools 3, a reference cutting edge 5 used only for measuring the position of the cutting edge is mounted on the tool rest 2. Furthermore, the turret 2
In the lower part of FIG.
a, 6b, 6c, and 6d are provided to face each other at right angles in the Z-axis and X-axis directions.

Since the lathe 1 has the above configuration, when measuring the wear amount of the tools 3, as shown in FIG. 1, when the wear amount of each tool 3 before machining is zero, 2 to arrow E
, F direction to position the tool 3 to be measured at a predetermined cutting edge measurement position X1. In this state, move and drive the tool rest 2 in the directions of arrows A, B, C, and D.
As shown in the figure, the cutting edge 3a of the tool 3 to be measured is brought into contact first with the measurement surface 6b of the touch sensor 6, and then with the measurement surface 6a, and from the amount of movement of the tool post 2 in the x12 direction at that time, the cutting edge 3a is Find the x1Z coordinate of.

That is, when the cutting edge 3a comes into contact with the measurement surface 6b, the amount of movement XI of the tool post 2 in the X-axis direction! , then the cutting edge 3a
When the tool rest 2 comes into contact with the measurement surface 6a, the amount of movement Z of the tool post 2 in the Z-axis direction is determined. The cutting edge position XL, Z of the tool 3 from the reference point sp in the x- and Z-axis directions is the reference distance between the reference point SP and each measurement surface 6a, 6b in a state where no thermal displacement occurs. , (parameter value), then XL=X, -X, -
=(112, =2.-2・
...It can be obtained using (2). In this way, after measuring the position of the cutting edge 3a of each tool 3 in the X and Z axis directions, the tool rest 2 is rotated in the directions of arrows E and F to position the reference cutting edge 5 at the cutting edge measurement position X1, and similarly. The reference cutting edge 5 is also at cutting edge position I! X,
Measure ZLs. At this time, the measured amount of movement of the tool rest 2 is set to XI! @, ZI-s, the cutting edge position xLS1ZL of the reference cutting edge 5 is, from equations (1) and (2),
Ls=X, -Xl:6 ZL8=ZS-Zl'li. The measurement results are stored in the memory as cutting edge position measurement data, and then normal machining operations are performed on the workpiece.

During machining, the cutting edge 3a of each tool 3 wears out, so the position of the cutting edge 3a of each tool 3 is measured at every predetermined machining time to check whether the wear of each tool is within the allowable range. It is necessary to determine whether However, after a predetermined period of time has elapsed, thermal expansion occurs in each part of the lathe 1, and even if the cutting edge 3a is simply brought into contact with the touch sensor 6 and the cutting edge position at that point is measured, the value does not match the value of the tool 3. This includes the amount of wear and thermal displacement of the measurement system, making it impossible to obtain an accurate amount of wear. Therefore, before measuring each tool 3, first position the reference cutting edge 5 at the cutting edge measurement position X1,
The cutting edge position of the reference cutting edge 5 is measured to determine the amount of thermal displacement of the measurement system.

That is, since the reference cutting edge 5 is not used for machining the workpiece, the cutting edge position XLs1zLS with respect to the tool rest 2 is
is always constant. Therefore, as shown in FIG. 1, the turret 2 and touch sensor 6 may
When moving from the position shown by the solid line to the position shown by the dotted line in the figure, the amount of movement in the X and Z axis directions when measuring the reference cutting edge 5 is xES', zl! 9', the amount of movement xes'
%Z,,' minus the movement amount x59, Zo measured at the time when there is no thermal displacement of the reference cutting edge 5, and the t binary value becomes the thermal displacement amount ΔjxT1ΔI2□ of the measurement system.

” =x!s '-x2s
−=(31Δ'=Z!S"E'J
...(4) In addition, each thermal displacement amount Δ'XT'
Δe2□ includes the amount of thermal displacement Δ~8, Δ
12. and the amount of thermal displacement Δ482 occurring on the touch sensor 6 side
, Δl should be included.

In this way, once the measurement system, that is, the amount of thermal displacement Δ'XT%Δ12 occurring between the touch sensor 6 and the tool post 2 is known, the position of the cutting edge of each tool 3 is measured according to the procedure described above. The amount of movement of the turret 2 for each tool 3, X, l,
When ZE is measured, the movement amount X e ', Z E
' includes the thermal displacement amounts Δ'XT and Δ12a, so the value obtained by subtracting the thermal displacement amounts becomes the true blade edge position. In other words, the position of the cutting edge after wear xLA1ZLA1 movement amount x
! ', 6', The relationship between the amount of thermal displacement Δ-0, Al and the reference distance X5, Z between the reference point SP and each touch sensor 6 in a state where there is no thermal displacement as a parameter value is as follows: +X,'-Δ1xT=X.
−−−−−−<5]z+z'−Δl=Z
...(6) L^ ε
zt S, xLA-x-x, :'+Δζ□=xS-x6'+(xl
:s'-X,s)...(71ZLA=Zs-2
I:'10Δ12T=ZS-Z,' + (ZES'
7Z,,l -=(81. As a result, the position of the cutting edge of each tool 3 after machining can be obtained, so the wear amount ΔT, ΔL2 in the X-axis and Z-axis directions of each tool is (1 )
, (2), (7), and (8), ΔLX=xL−xLA= (xS ”E)−(xS−x
l:' + (XE9' -XJ= (X,' -X--
(X,'-X,,) , ,,
,,,,(glΔL2=ZL−ZL,−(Z9−Z−−
(Z, −Z,' + (Z!S' −Z,)= (Z,
,' −Z,) −(z,' −z,,)
・・・・・・(It becomes 1ω.

As a result, the amount of wear ΔL and ΔL2 that occurs on each tool 3 is determined by the amount of wear (ΔL2) before and after the occurrence of wear, that is, the movement of each tool before and after machining.
From the difference between (X,,x,', z,,z,'), the amount of movement of the reference cutting edge 5 before and after machining (X11:9, Xl!9
' , z, , ZE9''.

In addition, in the above embodiment, unnecessary calculation operations and dimensions were added to the original wear measurement operation in order to clarify the relationship between each dimension. The only difference is the amount of movement of the tool and the reference cutting edge from the measurement reference position to the cutting edge detection means, and as long as such a difference can be determined, the movement mode of each tool 3 and the reference cutting edge 5 may be in any manner. Of course words. In addition, it is not necessary to obtain the above-mentioned difference in movement amount as a numerical value, and each tool 3 and reference cutting edge 5 are
, (as expressed in equation 11), it is naturally possible to control the movement by 1ζ and calculate the amount of wear from the resulting difference in coordinate positions.

Further, as the reference cutting edge 5, even if a special measuring cutting edge is not used, if there is a tool that happens to not be used for machining before or after wear measurement, that tool may be used as the reference cutting edge.

Further, it is also possible to set a specific part (for example, some protrusion, etc.) that is not involved in normal machining of the tool 3 as the reference cutting edge.

(g) 0 Effects of the Invention As described above, according to the present invention, before and after machining, the reference cutting edge 5 not used for machining is moved from the measurement reference position such as the reference point SP to the cutting edge detection means such as the touch sensor 6. and the amount of movement at that time x55, x6', ZES,,ZES
”, and then calculate the value obtained by subtracting the difference in the movement amount of the reference cutting edge from the difference between the separately calculated tool movement amounts before and after machining X5, x, ', z, z', and calculate the requested value. Wear amount ΔLx
1ΔL2, so even if there is a time difference between the measurement operations of the cutting edge position before and after wear, and thermal displacement occurs in the measurement system during that time, the amount of wear can be accurately measured while eliminating the thermal displacement. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of a lathe to which an embodiment of the method for measuring the amount of tool wear according to the present invention is applied, and FIG. 2 is a plan view showing an example of the method for measuring the position of the cutting edge. 2... Tool support means (turret) 3... Tool 5... Standard cutting edge 6... Cutting edge detection means (touch sensor) sp...
...Measurement reference position (reference point) x65, zES, x
,s',zES'x! ,z! , xe' , zE' ...Movement amount Applicant Yamazaki Mazak Co., Ltd. Agent Patent attorney Phase 1) Shinji (and 2 others)

Claims (1)

[Claims of Claims] A method for measuring the amount of tool wear, in which a tool mounted on a tool support means is moved from a measurement reference position to a cutting edge detection means before and after machining, and the amount of tool wear is determined from the difference in the amount of movement at that time. Before and after machining, move a reference cutting edge that is not used for processing from the measurement reference position to the cutting edge detection means, find the difference in the amount of movement at that time, and calculate the difference in the amount of movement of the tool from the difference in the amount of movement of the tool obtained. A method for measuring tool wear in a machine tool, which calculates a value by subtracting the difference in travel distance, and uses the calculated value as the wear amount.