JPS623608A - Hole diameter measuring instrument - Google Patents

Abstract

PURPOSE:To measure accurately the hole diameter of goods by moving the contact of a touch sensor in two directions orthogonal to each other relatively in the circular hole of goods to detect relative extents of movement of three points brought into contact with the peripheral wall part. CONSTITUTION:When the contact of a touch sensor 6 is inserted into a circular hole W1 of goods, a moving device 10 is controlled by a controller 11 in this state to move relatively the sensor 6 and goods in X and Y directions alternately. First, the sensor 6 and goods are moved in X and Y directions by the device 10 until the contact is brought into contact with three points P1, P2, and P3 on the peripheral wall face of the hole. On a basis of relative extents of movement in X and Y directions among three points P1, P2, and P3 on the peripheral wall face of the hole, a diameter D of the circular hole W1 is operated by an operator 18 with the length of the longer side of a right-angled triangle T inscribed to this hole as T1. Thus, the influences of the blind sector of the sensor 6 are absorbed to measure accurately the diameter D of the circular hole W1 without centering the circular hole W1 for hole diameter measurement.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improved technique for a hole diameter measuring device for measuring the hole diameter of a circular hole with a through hole or a closed end opening in an article.

(Prior Art) Generally, in a processing device that automatically processes, for example, a circular cylinder bore through a cylinder block that constitutes an engine part, by numerical control, it is necessary to check whether or not the bore has been accurately machined to the target dimensions and shape. In order to check this and input the error from the normal size and shape as correction data for the next bore machining, the inner diameter (hole diameter) of the bore after machining is automatically measured.

By the way, when automatically measuring the hole diameter of a circular hole opening in an article, such as the cylinder bore of a cylinder block,
For example, a touch sensor having a contact that can be inserted into a circular hole of an article and can come into contact with the peripheral wall surface of the article is provided, and the touch sensor or the article is placed in a state where the contact of the touch sensor faces inside the circular hole. By moving the touch sensor relative to the object in the diametrical direction so as to pass through the center of the hole, and determining the amount of relative movement between the object and the touch sensor until the contact comes into contact with the peripheral wall surface facing the hole in the diametrical direction. One possible method is to measure the hole diameter.

(Problem to be Solved by the Invention) However, in the above case, in order to move the contact of the touch sensor so as to pass through the center of the circular hole, a centering operation is required to find the center of the circular hole. There is a problem in that centering work takes time and measurement time becomes longer.

In addition, the above-mentioned touch sensor usually does not output a contact signal when the contact is in true contact with the circumferential wall of the circular hole, and after that, the contact pushed against the circular hole is placed in a predetermined position relative to the center line of the sensor body. It has a so-called dead zone in which it outputs a contact signal only when it is displaced over a certain distance. Therefore, in the above case, the contact will be affected by the dead zone at two places where it contacts the peripheral wall surface of the hole, and the measured value will be slightly larger than the actual hole diameter, making it difficult to accurately determine the hole diameter. It is difficult to measure.

The present invention was made to solve such a problem, and its purpose is to place a touch sensor in a circular hole by focusing on the geometric property that the long side of a right triangle inscribed in a circle always passes through the center of the circle. The circular hole is moved relatively in two directions perpendicular to each other and brought into contact at three points on the circumferential wall surface of the circular hole, and the hole diameter of the circular hole is calculated based on data regarding the position of the three points or the relative movement amount of the touch sensor. Accordingly, it is possible to eliminate the need for centering a circular hole when measuring the hole diameter, reduce the influence of the dead zone of the touch sensor, and more accurately measure the hole diameter of the article.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention has a contact that is inserted into the circular hole of the article and can come into contact with the peripheral wall surface of the circular hole, as described above. Provide a touch sensor. Further, a moving device is provided to relatively move the touch sensor and the article in two mutually perpendicular x and y directions in a plane orthogonal to the center direction of the circular hole of the article, and based on the output of the touch sensor, The moving device is moved so that the contact of the touch sensor is sequentially and alternately moved relatively in the x and y directions until it comes into contact with the circumferential wall surface of the circular hole of the article, and the contact point forms each vertex of a right triangle in the circular hole. A control device is provided for control. and x between the contact points by the control device,
It is assumed that a calculation device is provided that calculates the length of the long side of the right triangle as the hole diameter of the circular hole of the article based on the relative movement amount in each direction of y or the x and y coordinates of each contact point.

(Function) With the above configuration, in the present invention, when the contact of the touch sensor is inserted into the circular hole of the article, the moving device is controlled by the control device in that state, and the touch sensor and the article are moved in x, y. relative movement in each direction alternately. Due to this relative movement between the touch sensor and the article, the contact of the sensor first moves in the X or Y direction from the insertion position in the circular hole relative to the article, and when it comes into contact with the peripheral wall surface of the hole, it moves again. Change direction by 90" and move in the y or x direction to touch the peripheral wall of the hole again, then move in the x or y direction parallel to and opposite to the initial movement direction and touch the same wall. At this time, the contacts move relative to each other in the X or Y direction orthogonal to each other, so if the three contact points with the circumferential wall surface of the circular hole are respectively designated as P1 to P3 in order,
The straight line connecting these contact points P1 to P3 forms a right triangle inscribed in the circular hole, and the long side of the right triangle passes through the center of the circular hole. During that time, the contact points P+, P2 and P2 of the contactor with the same wall surface are
, P3 (respectively X).

Y) or the above PI- whose origin is a predetermined position.
Each x, y coordinate of point P3 (coordinates of P+ point (x, y
), then 02 points are (x', y) or (x, y')
Then, 93 points are (x', y')) is calculated,
This relative movement IX, Y or P+, x, y of 93 points
Based on the coordinates (x, y), (x', y'), the length of the long side of the right triangle, that is, the diameter of the circular hole, is determined by the arithmetic device as follows: D = (X2 + Y2) or D = (( x-x')' + (y-y'>
2) Calculated as f.

Therefore, after inserting the contact of the touch sensor into any position in the circular hole of the article, the touch sensor and the article are moved alternately in the x and ■ directions until the contact comes into contact with the same wall surface at three points. Since the hole diameter of the circular hole is automatically calculated and measured by simply doing this, there is no need for centering work to find the center of the circular hole, and the hole diameter can be measured efficiently in a short time.

In addition, at the three contact points P+ to P3 where the contact point of the touch sensor contacts the peripheral wall surface of the hole, the contact point is displaced by a predetermined amount with respect to the sensor body due to contact with the same wall surface due to the dead zone of the touch sensor. A contact signal is output from the sensor. However, for example, the next contact point P2 (P3) is increased by the amount of excess of the measurement dimension due to the dead zone at the contact point PI (P2).
In this case, the sensor contactor contacts the peripheral wall surface of the hole early, that is, the contact point P1. There is a contact relationship so that the measured dimension between Pz (between P2 and P3) is smaller than the actual dimension, and as a result, the influence of the dead zone of the touch sensor is reduced as a whole, and the hole diameter of the circular hole can be made smaller. This means that accurate measurements can be made (see Figure 2).

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

In FIGS. 3 and 4, 1 is a circular hole W+ of a workpiece W (for example, an engine cylinder block).
This is a base in a machining center for machining (the same cylinder bore) by numerical control, and a two-axis table 2 extending horizontally in the left and right direction is placed on the base 1 so as to be able to slide in two directions, that is, in the front and rear directions. Supported. Further, an X-axis table 3 is mounted and supported on the two-axis table 2 so as to be able to slide in the X direction, which is the left-right direction along the two-axis table 2. It is positioned and fixed by aligning the center direction of the two axes (front-back direction).

On the other hand, reference numeral 4 denotes a column member erected at the rear end of the base 1, and a y-axis driving main shaft 5 is supported on the front surface of the column member 4 so as to be slidable in the y direction, which is the vertical direction. A touch sensor 6 is attached to the y-axis driving spindle 5 as a tool changer (not shown).
are replaceably installed. The touch sensor 6
consists of a sensor body 6a fixed to the y-axis driving spindle 5, and a contactor 6b supported by the sensor body 6a and capable of being inserted into a circular hole W+ of a workpiece W and coming into contact with the inner wall surface thereof. It has a dead zone that outputs a contact signal when the contactor 6b is displaced by a predetermined amount from the center line of the sensor body 6a due to contact with the wall surface of the circular hole W11. Note that this touch sensor 6 is used only when measuring the hole diameter of the workpiece circular hole W1.
It is attached to the machining spindle 5, and is replaced with various processing tools (not shown) for machining the circular hole W1 of the workpiece W when the workpiece W is being processed.

As shown in FIG. 1, the two-axis table 2,
The shaft table 3 and the y-axis driving spindle 5 are connected to an electric motor 7 via a known transmission mechanism such as a screw feeding mechanism (not shown).
-9, and operate these motors 7-9 to move the two-axis table 2 in two directions (back and forth) on the base 1, and to move the x-axis table 3 on the two-axis table 2 in the By sliding the y-axis driving spindle 5 along the column member 4 in the y-direction (left-right direction) and the y-direction (up-down direction), the workpiece W is moved in two directions, that is, the front-rear direction with respect to the touch sensor 6. Insert the contact 6b of the touch sensor 6 into the circular hole W+, and in this state, move the workpiece W and the touch sensor 6 at right angles to each other in the X-y plane perpendicular to the center direction (two directions) of the workpiece circular hole W1. A movable bag [10] is configured to be relatively movable in two directions: the X direction, which is the horizontal direction, and the Y direction, which is the vertical direction.

Furthermore, in FIG. 1, reference numeral 11 denotes a controller constituting a control device for controlling each of the motors 7 to 9 in the moving device 10, and output signals of the controller 11 are transmitted to each motor via drivers 12 to 14, respectively. Motor 7~
9 is input. Further, 15 to 17 are position detectors each comprising a potentiometer or the like for detecting the respective movement positions of the two-axis table 2, the x-axis table 3, and the y-axis driving spindle 5, and these position detectors 15 to 17 The respective output signals are input to the controller 11, and the position detectors 15 to 17 detect the movement positions of each table 2, 3 and the y-axis driving spindle 5 whose movement is controlled by the controller 11, and feed it back to the controller 11. let me,
Each of the motors 9 to 9 is operated until the detected movement position reaches the target position.

The output signal of the touch sensor 6 attached to the y-axis driving spindle 5 is input to the controller 11, and the contact 6b of the touch sensor 6 is connected to the circular hole W+ of the workpiece W.
The work W and the touch sensor 6 are sequentially and alternately moved in the x and y directions until the contact 6b comes into contact with the peripheral wall surface of the workpiece circular hole W1 based on the output signal of the touch sensor 6. By relatively moving the contact 6b, as shown in FIG.
3 at each vertex of a right triangle T inscribed in the hole W1.

Further, reference numeral 18 denotes a computing unit as a computing device for computing the hole diameter of the circular hole W+ of the workpiece W, and the computing unit 1
The output signals of the position detectors 16 and 17 for the X-axis table 3 and the Y-axis driving spindle 5 and the output signal of the controller 11 are input to 8, and in this calculator 18, the touch sensor 6 is inputted. Contact point P+ with the surrounding wall surface of circular hole W1
Based on the respective movement positions of the X-axis table 3 and the main shaft 5 detected by the position detectors 16 and 17 when a contact signal is output due to the contact at P3, the X direction between the contact points P+ and P2 is determined. The relative movement 1X in the horizontal direction and the relative movement MY in the y direction (vertical direction) between the contact points P2 and P3 are determined and stored, and based on these relative movements ff1X and Y, the right angle in the circular hole Wt is calculated. The length of the lower long side T1 of the triangle is calculated as the diameter of the circular hole W1. Incidentally, numeral 19 is a converter that converts the hole diameter calculated by the calculator 18 into a numerical value and outputs the converted signal.

Next, the operation in the above embodiment will be explained.

The X-axis table 3 is controlled numerically by the controller 11.
When the circular hole W1 of the upper workpiece W is machined by a predetermined processing tool mounted on the y-axis driving spindle 5, the processing tool on the y-axis driving spindle 5 is replaced with the touch sensor 6, and the above-mentioned The hole diameter of the workpiece circular hole W+ after processing is measured. In this measurement process, first, the y-axis driving spindle 5 is moved downward under the control of the controller 11 so that the touch sensor 6 is positioned at approximately the same height as the workpiece W, and then the X-axis table 3 is placed above it. When the workpiece W is moved so as to correspond to the y@center spindle 5, the two-axis table 2 retreats together with the X-axis table 3 and the workpiece W, and the contact of the touch sensor 6 is inserted into the circular hole WI of the workpiece W. 6b is inserted.

In this state, as shown in FIG.
The position inserted into the workpiece circular hole Wi is set as a reference point PO, and the contactor 6b rises in the y direction relative to the workpiece W from the reference point PO, and the contactor 6b makes first contact with the peripheral wall surface of the circular hole W1. When a contact is made at point P+, the upward movement of the y-axis moving main shaft 5 is stopped by the output of a contact signal from the touch sensor 6, and the x-axis table 3 and the y-axis moving main shaft 5 corresponding to the first contact point P1 at that time are Each movement position of the main shaft 5 is detected by the position detectors 16 and 17, and is stored in the arithmetic unit 18.

Next, by moving the x-axis table 3 in the X direction, the workpiece W is horizontally moved in the right direction in FIG.
b comes into contact with the peripheral wall surface of the circular hole W1 at the second contact point P2, the horizontal movement of the x-axis table 3 is stopped by the output of a contact signal from the touch sensor 6, and the second
The respective movement positions of the X-axis table 3 and the y@spindle 5 corresponding to the contact point P2 are detected by the position detectors 16 and 17, respectively, and the arithmetic unit 18 detects the movement positions from the first contact point P1 to the second contact point. The relative movement ff1X (movement m of the x-axis table 3) of the sensor 6 in the X direction up to P2 is calculated and stored.

Thereafter, the touch sensor 6 moves downward in the y direction relative to the workpiece W due to the downward movement of the y-axis driving spindle 5,
When the contactor 6b comes into contact with the peripheral wall surface of the hole W1 at the third contact point P3, the downward movement of the y-axis driving spindle 5 is stopped by the output of a contact signal from the touch sensor 6. Each movement position of the x-axis table 3 and the y-axis driving spindle 5 corresponding to the three contact points P3 is detected by a position detector 16.
At the same time, the relative movement MY in the y direction of the sensor 6 from the second contact point P2 to the third contact point P3 (the amount of movement of the y-axis driving shaft 5) is calculated and stored in the calculation unit 18. Further, in the arithmetic unit 18,
The above two relative movements in the x and y directions ff1X,
Based on Y, the long side T of a right triangle T whose vertices are the contact points P1 to P3 and whose long side T+ passes through the center 0 of the circular hole W.
1, that is, the hole diameter of the workpiece circular hole W1 is D = (
The calculated hole diameter is converted by the converter 19 into a signal for numerical control and stored as correction data for the next machining of the workpiece W.

After this, the contact 6b of the touch sensor 6 is positioned at a predetermined position away from the peripheral wall surface in the workpiece circular hole Wl by the movement of the X-axis table 3, the y-axis driving spindle 5, or both, and then the two-axis The forward movement of the table 2 causes the contact 6b of the sensor 6 to be taken out of the circular hole Wi, and thus the measurement of the hole diameter for one workpiece W is completed. Thereafter, the same operation as above is repeated for each workpiece W.

Therefore, in this embodiment, the contact 6b of the touch sensor 6 is inserted into an arbitrary position in the circular hole W1 of the workpiece W, and is moved in each direction of y, x, and y until it comes into contact with the peripheral wall surface of the hole W1. By simply moving relative to the workpiece W in order, the relative movement mX, Y between each contact point PI-P3 causes the hole W1 to be
Since the inner diameter of the touch sensor 6 is calculated, the touch sensor 6 is
This eliminates the need for centering work to find the center 0 of the circular hole W1, as in the case of directly measuring the hole diameter by relatively moving it in the X or y direction so that b passes through the center O of the circular hole W1. , hole diameter can be measured efficiently in a short time.

Further, the touch sensor 6 and the workpiece W are arranged at x, which is perpendicular to each other.
Since the contact 6b of the sensor 6 is brought into contact with the circumferential wall surface of the hole W1 by sequential relative movement in each direction of y, even if the touch sensor 6 has a dead zone, for example, in the X direction at the second contact point P2. For the dead band valve, the subsequent third contact point P3 is displaced closer to the second contact point P2, and the relative movement MY between both contact points P2 and P3 becomes shorter. Due to this relationship, the influence of the dead zone of the touch sensor 6 is reduced as a rest, and the hole diameter of the workpiece circular hole W1 can be accurately measured.

In the above embodiment, the touch sensor 6 was moved in order in the y, x, and y directions relative to the workpiece W.
, y, and X directions, and the same effects as in the above embodiment can be achieved.

Furthermore, in the above embodiment, the relative movement f in the X direction between the sensor 6 and the workpiece W from the first contact point P+ to the second contact point P2 is
Although the hole diameter of the workpiece W is calculated based on f1X and the relative movement MY in the y direction from the second contact point P2 to the third contact point P3, the position of each of the contact points P1 to P3 is X with the origin at a predetermined position in the x-y plane (for example, the reference point Po).

Detected by the y coordinate, and the x, y of each contact point P1 to P3
The hole diameter of the workpiece W may be calculated based on the coordinates. That is, the position coordinates of the contact point P1 are (x,
y), the position coordinates of contact points P2 and P3 are (x', y) (or (X.

y')) and (x', y'), and the workpiece circular hole W
As mentioned above, the hole diameter of 1 is obtained as D=((x-x'>2+(Y-y')2)).

Further, in the above embodiment, the case where the diameter of the circular hole W1 of the workpiece W is measured is illustrated, but the present invention can also be effectively applied to the case where the diameter of the circular hole opened in various articles is measured. Of course you can.

(Effects of the Invention) As described above, according to the present invention, the contact of the touch sensor inserted into the circular hole of the article is alternately moved in the X and 17 directions perpendicular to each other until it contacts the peripheral wall surface of the hole. Based on the x and y coordinates of each contact point, the diameter of the circular hole is determined by the length of the right triangle inscribed in it. By calculating the side length, there is no need to center the circular hole when measuring the hole diameter, and the influence of the dead zone of the touch sensor is absorbed, allowing more accurate measurement of the hole diameter of the circular hole. This has excellent practical effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, FIG. 1 is a block diagram showing the overall configuration of the hole diameter measuring device, FIG. 2 is an explanatory diagram showing the concept of measuring the hole diameter of a workpiece, and FIG. FIG. 4 is a schematic front view of the diameter measuring device, and FIG. 4 is a schematic side view thereof. 3...X-axis table, 5...VIIIFJJ spindle,
6...touch sensor, 6b... contact, 10...
Mobile device, 11... Controller, 18... Arithmetic unit,
W...Work, W+Figure 3

Claims (1)

[Claims] (1) A touch sensor having a contact element inserted into a circular hole of an article and capable of contacting the circumferential wall surface of the circular hole; a moving device that relatively moves in two y directions; and a moving device that sequentially and alternately moves a contactor of the touch sensor relative to the x and y directions until it comes into contact with the peripheral wall surface of the circular hole of the article based on the output of the touch sensor. a control device that controls the moving device so that the contact points form each vertex of a right triangle in the circular hole; and x between the contact points by the control device;
and a calculation device that calculates the length of the long side of the right triangle as the hole diameter of the circular hole of the article based on the relative movement amount in each direction of y or the x and y coordinates of each contact point. Hole diameter measuring device.