JPH05228799A - Touch sensor tool - Google Patents

Abstract

PURPOSE:To improve responsiveness and accuracy of a touch sensor tool mounted on a working machine such as a machining center so as to measure the form and the size of a work. CONSTITUTION:A touch sensor tool 100 to be mounted on a working machine is provided with a main body 115 in one body with a shank 110 to be inserted into a main spindle, and a cup shaped housing 120 to be fitted to the main body 115. A block 140 is fitted to the center part of the housing 120 through a spring 135. A probe 160 is screwed into the underside of the block 140. A light sensor unit 200 is arranged between the block 140 and the housing 120. The light sensor unit 200 is composed of a light source 210 and a light sensor 230, and the light sensor 230 is provided with light receiving faces divided into four parts. When the extreme end of the probe 160 is contacted with a work, the light source 210 is displaced, and balance of light quantities received with the four divided light receiving faces is changed. Variation of an electric signal due to this variation is analysed, so as to measure the form and the size of the work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus which is installed in a multi-tasking machine to measure the shape and size of an object by contacting the object.

[0002]

2. Description of the Related Art In a complex machining machine tool such as a machining center or an FMS, a workpiece or the like is automatically supplied to the machining machine tool to perform unmanned automatic machining. In order to automatically process the supplied work, the shape of the work,
It is necessary to measure the dimensions and set the processing origin. For this purpose, the multi-task machine tool is equipped with a sensor to measure the shape and dimensions of the work.

FIG. 5 shows an outline of the machining center 1, in which a main shaft 20 is arranged vertically with respect to a column 10 moving on the base in the front-rear direction of arrows A and B. It is equipped so that it can move in the directions of arrows C and D. The table 30 is mounted so as to be movable in the directions of arrows E and F, which are horizontal directions perpendicular to the directions of arrows A and B, and a work 35 is supplied onto the table 30 via a pallet 32.

An ATC (Automatic Tool Changer) generally designated by 40 has an ATC arm 42 and a tool transfer arm 45. The tool magazine 50 has a large number of tool pockets 54 in a chain 52, for example, and stores a tool 60 for replacement. The ATC arm 42 rotates in the directions of arrows G and H, and the tool transfer arm 45 rotates in the directions of arrows I and J.
Both arms 42, 45 cooperate to automatically exchange tools between the spindle 20 and the tool magazine 50. FIG. 5 shows the spindle 20
The state in which the touch sensor tool 100 for measurement is attached is shown in FIG. The touch sensor tool 100 has a probe 160, and the tip of the probe 160 contacts the work 35 on the table 30 to measure the shape and size of the work 35.

FIG. 6 shows the mechanism of the conventional touch sensor tool 70. The upper end of the probe 72 is connected to a disk-shaped block 74, and three pins 76 radially project from the periphery of the block 74. There is. Each pin 76 is sandwiched between contacts 78 formed in a V shape, and each contact 78 has a wire 79.
Are electrically connected by. An upper part of the block 74 is connected to an adjusting piece 81 via a spring 80, and an adjusting screw 82 screwed into a main body 71 of the touch sensor tool 70 is adjusted to apply an appropriate downward pressure to the probe 72. When the probe 72 comes into contact with the work 35 and the probe 72 is displaced in the axial direction or in the direction orthogonal to the axial direction, the pin 76 separates from the contact 78. This is electrically detected to measure the shape and size of the work 35.
It is possible to improve accuracy by using an optical sensor instead of a touch sensor tool using mechanical electrical contacts. For example, Japanese Unexamined Patent Publication No. Hei 2-161301 discloses a measuring device which constitutes an optical sensor with a light emitting element and a light receiving element and detects movement of a probe in the X, Y, and Z axis directions.

[0006]

In the conventional mechanical contact type touch sensor tool described above, since a certain amount of force is applied to the probe 72 to operate, it is not suitable for high precision measurement. Repeat accuracy was also insufficient.
Further, this type of sensor detects whether or not the tip of the probe comes into contact with the work, and has only an ON-OFF detection function. The one disclosed in Japanese Patent Laid-Open No. Hei 2-161301 detects only displacement in one axis direction or displacement in a two-dimensional plane perpendicular to the one axis, and simultaneously detects displacement in three axes directions. is not. JP-A-1-
Japanese Patent No. 6836 proposes a device that measures the magnitude of force using an optical sensor. However, the sensor disclosed in this publication measures a force, not a shape and a dimension due to displacement. Therefore, the present invention is provided with an optical contact and has X, Y, Z
The present invention provides a touch sensor tool for a machine tool capable of simultaneously measuring the displacement amounts of the three axes.

[0007]

SUMMARY OF THE INVENTION A touch sensor tool of the present invention includes a housing integrated with a tool body, a probe disposed on the inner peripheral side of the housing, and a probe which always returns to a reference position with respect to the housing. And a supporting spring. The basic means is that an optical sensor unit is provided between the probe and the housing.

[0008]

When the tip of the probe comes into contact with the work and is displaced, the optical sensor unit detects this displacement and emits an electric signal. By analyzing this signal, the shape and size of the work can be continuously measured at high speed and with high accuracy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing the entire structure of a touch sensor tool of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. A touch sensor tool, generally indicated at 100, has a shank 110 and a pull stud 11
It is attached to the spindle 20 of the machining machine tool by using the number 2. A cup-shaped housing 120 is fixed to a lower portion of a main body 115 continuous with the shank 110 via a bolt 122. A ring member 130 is fixed to the inside of the cup-shaped housing 120 with bolts 132. A cylindrical block 140 is arranged at the center of the inside of the ring members 130, and the ring members 130 are connected by bent plate springs 135.

As shown in FIG. 2, the springs 135 are arranged at three locations on the circumference, and the block 140 is elastically supported in a position where its axis coincides with the center line of the shank 110 in a natural state. The lower part of the block 140 is the housing 120.
Although it protrudes from a round hole provided at the bottom of the housing, a seal member 150 is attached between them to prevent dust from entering the inside of the housing 120. The probe 160 is attached to the lower portion of the block 140 via the screw portion 162. Probe 1
A spherical contactor 164 is formed at the tip of 60. Between the ring member 130 and the block 140, 120 on the circumference.
Three photosensor units 200 are mounted at angular intervals of degrees.

FIG. 3 shows the details of the optical sensor unit 200. The optical sensor unit 200 is a point light source 21.
0 and the optical sensor 230 are combined. Light source 21
For example, 0 is a structure in which a pinhole is attached to the light emitting surface of the LED to emit point light 212. The optical sensor 230 includes four light receiving portions 232A and 232.
A light receiving surface 232 having B, 232C, and 232D is provided. The light source 210 is attached to the block 14 via a fixture 220.
The optical sensor 230 is fixed to the outer peripheral portion of
It is fixed to the inside of the ring member 130 via.

In the natural state, the light source 210 and the optical sensor 230 are arranged so that the optical axis of the light source 210 and the center of the light receiving surface 232 of the optical sensor 230 coincide with each other. The light source 210 and the optical sensor 230 are connected to an electric circuit 250 disposed inside the housing 120, and the electric circuit 250 is connected to the transmitter 2 via a line 260.
Go to 70. The transmission unit 270 transmits data to the reception unit 280 provided on the side of this machine. That is, when the touch sensor tool 100 is mounted on the spindle 20, the transmitter 270 and the receiver 280 are close to each other and send data in a non-contact manner.

Next, the operation of the present invention will be described. Light source 210
When the beam 212 emitted from is evenly received by the four-divided light receiving surface 232 of the optical sensor 230,
Four light receiving parts 232A, 232B, 232C, 232D
Emits an equal electrical signal. When the light source 210 moves in either of the axes X and Y, the four light receiving units 2
The balance of the amount of light received by 32A, 232B, 232C, and 232D changes. Further, when the light source 210 moves in the Z-axis direction, the intensity of the amount of light incident on the four light receiving portions changes. Therefore, the four light receiving parts 232A, 232
Since the electric signals generated from B, 232C, and 232D change, the moving direction and the moving amount of the light source 210 can be detected by analyzing this signal. By analyzing the signals of the three optical sensor units, the probe 1
The center of rotation of 60 is found, and accurate detection can be achieved.

FIG. 4 is a block diagram of an electric circuit which constitutes this apparatus. An optical sensor unit 200 including a light source 210 and an optical sensor 230 is provided with three units 200A, 200B, and 200C that divide the circumference into three equal parts. In the first optical sensor unit 200A, the light source 2
10 is driven by the power source 201, and the LED emits light.
When the light source 210 and the optical sensor 230 relatively move in the X, Y, and Z directions, the amount of light received by the four-divided light receiving portions of the optical sensor 230 changes, and the generated current value changes. The electric circuit 250 has an amplifier 250A and converts each current generated by the four-divided light receiving section into a voltage and amplifies it. The amplified voltages a, b, c, and d are sent to the arithmetic circuit 250B, addition, subtraction, and division are calculated, linear correction is performed by the correction circuit 250C, and data is obtained as analog data of X ₁ , Y ₁ , and Z _1. It is sent to the communication format converter 250D. Similarly, from the second optical sensor unit 200B, X ₂ , Y ₂ ,
The Z ₂ data is obtained, and the third optical sensor unit 200 is obtained.
The data of X ₃ , Y ₃ , and Z ₃ can be obtained from C as well. The data communication format exchanger 250D has a function of converting each analog voltage into a standard for data communication, for example, a standard of a serial data transmission system represented by the RS232C system. The data converted for communication is sent to the transmission unit 270 via the line 260 and is transmitted to the reception unit 280 on the main body side in a contactless manner by an electromagnetic induction method or the like. The data transmitted to the unit side is the displacement amount calculation processing unit 4
In _{00, X 1 ~X 3, Y} 1 ~Y 3, the center of rotation than the data Z ₁ to Z ₃ are determined, X-axis, Y-axis, the actual displacement amount in the Z-axis direction is calculated. The result is sent to the central processing unit 500 and used for CNC control. The touch sensor tool 100 having the above functions is attached to the spindle 20, and the distance between the touch sensor tool 100 and the table 30 on which the work 35 is placed is NC controlled.
The tip 164 of the probe 160 of the touch sensor tool is brought into contact with the surface of the work 35. When the tip 164 of the probe 160 contacts the work surface, the optical sensor unit 2
00 detects this contact and emits a signal. Touch sensor tool probe 160 length and spherical contactor 1
Since the diameter dimension or outer dimension of 64 is given as a parameter, the NC device can recognize the distance between the spindle 20 and the work 35. Touch sensor tool 10
By bringing 0 into contact with each surface of the work 35, the shape and dimensions of the work 35 can be measured. Since the measurement uses an optical sensor, it has high responsiveness, and is continuously executed with high accuracy. NC that recognizes the shape and size of the work
The machine automatically sets the machining origin and starts automatic machining.

[0015]

As described above, according to the present invention, in a touch sensor tool which is mounted on a spindle of a machining machine tool and comes into contact with a work on a table to measure the shape and size of the work, a housing attached to the shank of the tool. Against
A cylindrical block provided on the head of the probe that contacts the work is attached via a spring. Then, an optical sensor unit is attached between the housing and the block to optically detect the movement of the probe. Since the optical sensor unit is used, the contact of the probe with the work can be detected with high accuracy and continuously. The control device can accurately recognize the shape and size of the work and execute automatic processing. In the present embodiment, the device in which the touch sensor is built in the tool attached to the main shaft has been described, but the present invention can be applied to other types of touch sensors.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an explanatory diagram of an optical sensor unit.

FIG. 4 is an electric circuit diagram of an optical sensor unit.

FIG. 5 is an electric circuit diagram of the optical sensor unit.

FIG. 6 is a perspective view showing an example of a processing machine tool to which the present invention is applied.

FIG. 7 is an explanatory diagram of a conventional touch sensor tool.

[Explanation of symbols]

 1 Processing Machine Tool 20 Spindle 30 Table 35 Work 40 Automatic Tool Changer 50 Tool Magazine 100 Touch Sensor Tool 110 Shank 115 Tool Body 120 Housing 130 Ring Member 135 Spring 140 Block 160 Probe 200 Optical Sensor Unit 210 Light Source 230 Optical Sensor 232 4 Division Light receiving surface

Claims (2)

[Claims] 1. A touch sensor tool mounted on a processing machine for measuring the shape and size of an object by contacting the object, the probe being disposed on the inner peripheral side of the housing, and the probe being mounted on the housing. On the other hand, an elastic member that always returns to the reference position and at least one optical sensor unit that is disposed between the probe and the housing to optically detect the three-dimensional displacement amount of the probe simultaneously are provided. Touch sensor tool. 2. The touch sensor tool according to claim 1, wherein the optical sensor unit comprises a light source and an optical sensor having a four-divided light receiving section for receiving light from the light source and converting the light into an electric signal.