JPS61213625A - Generator for measurement signal - Google Patents

Abstract

PURPOSE:To speed up a measuring operation and to enlarge the object of measurement by providing a detection unit which generates a signal according to a change in the attitude of a measuring element, a probe body, and a position changing mechanism. CONSTITUTION:A prove 10 consists of the probe body 15, the position changing mechanism 16 for the measuring element 16, the detection unit 17, and the measuring element 18. The probe 10 is a measurement signal generator having a function which obtains the quantity of inclination of the measuring element 18 or the quantities of inclination at the moment and after the measuring element 18 abuts on the object of measurement, and when the measuring element 18 slants, the detection unit 17 outputs continuously an analog signal corresponding to the quantity of inclination. Then, the position changing mechanism 16 for the measuring element 18 which constitutes a measuring element attitude adjusting device is provided to the side of the probe 10 and the driving means 30 which operates the mechanism 16 is provided at another place separately; while some measurement signal generator is in measuring operation, the position of the measuring element 18 of another measurement signal generator is adjustable, and consequently the measuring operation is speeded up and the object of measurement is enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a measurement signal generator used as a probe in, for example, a three-dimensional measuring machine, and particularly relates to a measurement signal generator that is used as a probe in a three-dimensional measuring machine, and in particular, a measurement signal generator in which the position of a probe with respect to the probe body can be changed. Regarding the measurement signal generator, it can be used to improve the efficiency of measurement work.

[Background technology and its problems]

The object to be measured placed on the stage and the probe supported by the measuring machine body are moved relative to each other in one, two, or three dimensions by a moving mechanism, and the measurement surface of the object to be measured and the probe are measured. Measuring machines are known that measure the dimensions of an object to be measured by detecting the amount of displacement relative to the object and processing the detected amount of displacement in a predetermined manner using a data processing device. This measuring machine, for example, a three-dimensional measuring machine, is equipped with a displacement detector separate from the probe for detecting the relative movement between the measuring stylus and the object to be measured by the moving mechanism, and the measuring stylus is placed on the measurement surface of the object to be measured. It has a structure that measures the dimensions of the object to be measured by capturing the moment of contact, latching the amount of displacement detected by the displacement detector at that time, and processing the multiple coordinate values obtained by sequentially repeating this process. It is common that

A so-called touch signal probe is used to detect the contact between the probe and the measurement surface. This touch signal probe is configured such that a measuring stylus is supported by the probe body so as to be tiltable and returnable to its original position, and to emit a touch signal when the measuring stylus touches an object to be measured and tilts. Other types of probes are used, for example, to measure roundness, and measure the amount of tilting of the measuring tip after it contacts the object to be measured, or the amount of tilting of the measuring tip at the moment of contact and thereafter. Some are designed to capture and emit an analog signal. Both probes are collectively referred to as a measurement signal generator.

In the case of the above-mentioned three-dimensional measuring machine, in order to perform automatic measurements by automatically operating the moving mechanism according to a predetermined program by a computer, it is necessary to maintain a fixed attitude of the measuring point with respect to the probe body. The possible shapes of the object to be measured are extremely limited, and the usability of the measuring device is narrowed.

Therefore, there are commercially available probes in which the probe body is provided with an attitude adjustment device so that the attitude of the probe with respect to the probe body can be changed. According to this, the attitude of the probe can be adjusted according to the measurement surface, which is convenient for a measuring machine that performs automatic measurements.

However, although this measurement signal generator with a built-in attitude adjustment device contributes to automation, it has problems that cause disadvantages and inconveniences in the structure of the measuring device, measurement efficiency, applicability of the measuring device, etc. That is, (1) it is necessary to adjust the posture of the probe for each measurement surface, which increases the time required for measurement work and reduces work efficiency;

(2) Depending on the driving means of the posture adjustment device, heat may be generated or vibrations may be generated, which may cause problems in terms of measurement accuracy.

■The measurement signal generator has become larger due to the attitude adjustment device, which limits the effective space for measurement and the measurable shape of the object to be measured, and also prevents problems such as deflection due to the increased weight of the measurement signal generator. Therefore, the structure of the measuring device must be strong.

■Even though the posture of the measuring head can be adjusted, the length of the measuring head
Since the size, shape, etc. are constant, in order to achieve complete automation, when measuring objects with complex shapes, many measurement signal generators are attached to the main body of the measuring machine, and these can be switched to perform the measurement work. This also causes the problem (2) above.

■Since the above-mentioned Φ causes the measurement head attitude adjustment range for one measurement signal generator to be small, it is necessary to prepare multiple measurement signal generators even for measurement surfaces of the same shape. , it is also economically disadvantageous.

(2) Furthermore, depending on the shape of the object to be measured, the attitude of the probe may be adjusted at a position that is difficult to see visually, and it may not be possible to confirm this.

[Purpose of the invention]

The problem of the present invention is that the conventional measurement signal generator with an attitude adjustment device is configured to include its driving means from the technical concept of the entire measuring machine that adjusts the attitude of the probe during the measurement process. This was done by recognizing that.

An object of the present invention is to make the measuring head position changing mechanism constituting the measuring head attitude adjustment device and the driving means for operating the same separate and independent. The position of the measurement head of the measurement signal generator can be adjusted, speeding up the measurement work for the entire measuring device, and it is also possible to expand the range of measurement objects that can be measured, expanding the range of application. The purpose of the present invention is to provide a measurement signal generator that can perform

[Means and effects for solving problem 101] For this reason, the present invention provides a measurement signal generator that includes a measuring tip that is brought into contact with the measuring surface of the object to be measured, and a measuring tip that is moved by the reaction force of the object to be measured. A detection unit configured to include a detection unit capable of changing its posture and capable of returning to its original posture when the reaction force is removed, and generating an output signal when the posture of the measuring head changes. , a probe body having a shank portion for attaching to the measuring instrument body, and a probe body for forcibly changing the position of the measuring point with respect to the probe body, which is provided on another stationary body outside the probe body. It is characterized in that it includes a position change mechanism driven by a drive means.

〔Example〕

FIG. 1 is an overall perspective view of a coordinate measuring machine in which a measurement signal generator according to this embodiment is used. First, the structure of this coordinate measuring machine will be explained.

At the top of the base l, a stage 3 is arranged between the two left and right vaginal wall members 2, and this stage 3, on which the object to be measured 4 is placed, is attached to the base 1. On the other hand, it is movable in the Y-axis direction. A beam member 6 is installed across the upper portions of the two left and right columns 5 fixed to the base l, and a slider 7 is attached to the beam member 6 so as to be slidable in the X-axis direction. A spindle case 8 integrated with the slider 7 is provided with a rectangular columnar spindle 9 movable in the vertical direction, that is, in the Z-axis direction, and a probe lO, which is a measurement signal generator, is connected and supported at the lower end of the spindle 9. 0 or more pillars 5, beam members 6
, the slider 7, the spindle 9, etc., constitute a measuring machine main body 11, and a probe IO is attached to this measuring machine main body 11.

The movement of the workpiece table 3 in the Y-axis direction with respect to the base l is automatically performed by a drive device such as a morph or a ball screw disposed inside the bellows cover 12, and
Axial movement and biaxial movement of the spindle 9 are also carried out by the beam member 6.
, by a drive device built into the spindle case 8.

These driving devices and the like constitute a moving mechanism that causes a three-dimensional displacement of the measurement object 4 and the probe 10, and the stage 3 is a movable member of this moving mechanism in the Y-axis direction. , the measuring instrument main body 11 is a stationary member. Further, the slider 7 and the spindle 9 are movable side members in the X-axis direction and the Z-axis direction, and the beam member 6 and the spindle case 8 are stationary side members.

A probe stocker 13 is attached to the rear end of the stage 3. FIG. 2 shows this probe stocker 13.
The probe stocker 13 has a bottom portion 13A fixed to the top surface of the stage 3, and leg portions 13B standing vertically from the bottom portion 13A.
, a top section horizontally provided on the leg section 13B with an interval from the top surface of the stage 3], and a top section 3C, which has a U-shape on the side.

A planar U-shaped groove 14 that opens forward is formed in the top portion 13C, and the probe 10 is inserted into this groove 14 and is supported by the probe stocker 13. A plurality of grooves 14 are formed in the probe stocker 13 so that a plurality of probes 10 can be supported.

The probe 10 includes a probe body 15, a probe position changing mechanism 16, a detection unit 17, and a probe 18. The probe 10 shown in FIG. Since this is a probe for measuring degree or cylindricity, the measuring stylus 18 that comes into contact with the measuring surface of the object to be measured 4 can change its posture by the reaction force from the measuring surface on the detection unit 17, specifically, it can tilt and tilt. The detection unit 17 is supported so as to be able to return to its original position once the reaction force is removed, and the detection unit 17 has a detection section that continuously outputs an analog signal corresponding to the amount of tilting of the probe when the probe is tilted. It is composed of: In this way, the probe 10
This is a measurement signal generator that has a function of capturing the amount of tilting of the probe 18 or the amount of tilting at the moment when the probe 18 contacts the object 4 to be measured and thereafter.

The probe main body 15 has a shank part 15A for attaching the probe IO to the spindle 9 constituting the measuring machine main body 11, and a tapered protrusion 15B and a flange part 15C provided at the lower part of the shank part 15A, A flange portion 15C is locked around the groove 14. A support member 19 having a horizontal length is attached to the lower surface of the probe body 15, and a screw shaft 21, which is a ball screw, is rotatably supported by bearing members 20 provided at both ends of the support member 19. be done. A nut member 22 screwed onto this screw shaft 21 whose axial direction is the horizontal direction is held inside a holding member 23, and the detection unit 17 is connected and supported by this holding member 23.

The upper surface of the holding member 23 slidably contacts the lower surface of the supporting member 19 to prevent rotation of the holding member 23, and when the screw shaft 21 rotates, the screw feeding action of the screw shaft 21 causes the holding member 2 to slide.
3 moves in the horizontal direction, and the position of the probe 18 is changed. The above supporting member 19, screw shaft 21, NAND member 22, etc. constitute a position changing mechanism 16 that forcibly changes the position of the probe 18.

One end of the screw shaft 21 protrudes from one bearing member 20,
The first clutch member 24 is attached to this protruding end. When the probe 10 is supported by the probe stocker 13, the first clutch member 24 passes through the hole 25 formed in the leg portion 13B and projects to the rear of the probe stocker 13.

A motor 27 is attached to the probe stocker 13 via a bracket 26, and a second clutch member 27, which is paired with the first clutch member 24, is provided on the output shaft of the motor 27, which is disposed on the probe stocker 13 side. It will be done. The first clutch member 24 and the second clutch member 28 constitute a magnetic clutch 29 that can be freely connected and disconnected. Further, the motor 27 constitutes a driving means 30 for operating the position changing mechanisms 16, and these position changing mechanisms 16
and the driving means 30 constitute a measuring head attitude adjustment device.

As described above, in the present invention, the position changing mechanism 16 and the driving means 3
0 and is arranged in a separate and independent state from the drive means 3
0 is provided in the probe stocker 13 which is a stationary body outside the probe main body 15.

A rotary encoder 31 is connected to the motor 27, and the rotary encoder 31 controls the motor 2.
7, that is, the amount of rotation of the screw shaft 21 when the electromagnetic clutch 29 is connected is detected.

Inside the spindle 9 constituting the measuring machine body 11, there is a probe attaching/detaching device for attaching and detaching the probe 10 from the spindle 9, and a device for rotating the attached probe 10 around a vertical axis for measuring roundness, etc. A device is installed to

In FIG. 1, an object to be measured 4 is attached to the object table 3 by the moving mechanism controlled by a computer, and a probe 10 is attached to the spindle 9 of the measuring machine main body 11.
are moved and displaced three-dimensionally. When the next measurement process according to a computer program is performed using the probe IO for measuring roundness, etc. shown in FIG. Change and adjust the position of the probe 18 to the specified position (.

That is, in FIG. 2, when a signal indicating that the next measurement step is to measure roundness, etc. is output from the control device of the coordinate measuring machine, the electromagnetic clutch 29 is connected and the motor 27 as the drive means 30 is connected. drives the rotation. As a result, the position change mechanism 16 is activated, and the screw shaft 2 rotates.
The detection unit 17 and the probe 18 are
is forced to move linearly in the radial direction of the probe body 15. This amount of movement is detected by the rotary encoder 31, and when the amount of linear movement of the contact point 18, etc. matches the diameter of the hole in the object 4 to be measured for roundness, etc., the controller 31 detects the amount of linear movement. The rotational drive of the motor 27 is stopped by this signal, and the electromagnetic clutch 29 is disconnected.

In this way, the position of the measuring stylus 18 is changed while the probe 10 is waiting in the probe stocker 13, and the step of changing the position of the measuring stylus 18 is carried out while the previous measurement process is being performed, and these steps are Measurement work time can be shortened because measurements can be performed simultaneously in parallel.

When the previous measurement step is completed, the document table 3 is moved in the Y-axis direction, and the probe stocker 13 is moved to a position below the spindle 9. Further, the slider 7 moves in the X-axis direction and the spindle 9 also descends, and the probe 10 is removed from the spindle 9 by the operation of the probe attachment/detachment device and is stored and supported at a predetermined position in the probe stocker 13. After this, the spindle 9 rises, and the slider 7 moves in the X-axis direction, and the position of the spindle 9 reaches directly above the probe 10 for measuring roundness, etc., where the change in the position of the measuring stylus 18 has been completed. Then, the spindle 9 is lowered and the probe 10 is mounted and supported on the spindle 9 by the probe mounting/detaching device.

Next, by the operation of the moving mechanism, the probe 10 is moved and displaced until the center axis of the hole, etc. of the object to be measured 4 whose roundness etc. is to be measured coincides with the center axis of the spindle 9, and the probe 18 moves toward the object to be measured. After contacting the measuring surface 4, the rotating device 51 for measuring roundness, etc. is driven. As a result, the probe 10 rotates around the vertical axis, and the probe 10 rotates around the vertical axis.
The roundness etc. are measured by the detection unit 17 which outputs an analog signal according to the amount of tilting of the sensor 8.

Note that the measurement of roundness and the like may be performed by not providing a rotation device inside the spindle 9 but by providing a turntable on which the object to be measured 4 is placed on the stage 3.

When the measurement of roundness and the like is completed, the probe 10 is housed and supported in a corresponding predetermined position of the probe stiffener 13 by the operation of the moving mechanism.

In the above, if the probe 10 for measuring roundness, etc. can be attached to the spindle 9 of the coordinate measuring machine, the coordinate measuring machine has the same functions as the conventional measuring machine for roundness, etc., and can also handle multiple coordinates. Compared to a method that detects the position and processes it to measure roundness, etc., this method has the advantage of significantly shortening the measurement time and obtaining a continuous analog signal.

In addition, the long screw shaft 21 can be attached to the probe 10 for measuring roundness, etc., and a large linear movement amount can be given to the probe 18. The roundness etc. of even large holes can be measured with one probe 10, the range of application of the probe 10 is expanded, and the number of probes can be reduced. For this reason, the range of the measurement object 4 that can be measured by the coordinate measuring machine is expanded, and it is no longer necessary to attach a plurality of probes to the spindle 9 as in the past, and the number of probes that act on the spindle 9 is reduced. The reduction in the weight of the probe eliminates the need to increase the strength of the structure of the coordinate measuring machine.

Further, since the driving means 30 for operating the position changing mechanism 16 of the probe IO is attached to the probe stocker 13 and is not provided on the probe 10, the weight of the probe 10 acting on the spindle 9 is reduced accordingly. At the same time, the probe 10 can be miniaturized, and the shape of the object to be measured 4 is no longer restricted, which expands the scope of application of the probe 10. It is also possible to increase the size of the position changing mechanism 16, and in this case also, the range of the measurement target 4 can be expanded. In addition, since the probe 10 and the drive means 30 are separated when the probe 10 is performing measurement work, it is possible to prevent adverse effects such as heat generation from the drive means 30 from reaching the probe IO during the measurement work. can.

In addition, since the measuring head 18 is constantly changing its position in the probe station 7 13, the measuring worker can visually check the measuring head 18.
You can confirm the change in the position of 8.).

The probes housed and supported in the probe stop 7 13 may be both those whose measuring points are changed in position and those whose measuring points are not changed, or only probes whose measuring points are changed in position may be housed and supported. .

Adjustment of the position of the probe is not limited to linear movement in the radial direction of the probe body as in this example; for example, adjustment of the probe body by swinging the probe about a horizontal axis, or about a vertical axis. In the case where the probe stocker 13 supports a plurality of probes whose measuring points are changed in position, the probe stocker 13 may be configured to rotate the probe vertically, move up and down along the vertical axis, or perform a combination of these movements. In this case, the driving means 30 such as a motor for operating the position change mechanism of the probe may be provided for each probe, but one driving means 30 may be used for a plurality of probes.

Since the probe in this embodiment was for measuring roundness, etc., the detection unit 17 had a detection section that outputs continuous analog signals. The device may include a detection unit that outputs a touch signal when a posture change occurs due to contact with an object.

That is, the probe may be a touch signal probe for measuring the coordinate position, length, etc. of the object to be measured using a displacement detector using, for example, an optical scale attached to a coordinate measuring machine, and if necessary, a measuring point. Any measurement signal generator may be used as long as it is equipped with a detection unit that includes a detection unit that generates an output signal when the object comes into contact with the object to be measured and changes its posture, and the position change mechanism 16 is configured. The detection unit 17 is not fixedly attached to the holding member 23, but is detachably attached, so that the detection unit for analog signal generation and the detection unit for touch signal generation can be replaced. Good too.

In this embodiment, the probe stocker 13 as a stationary body provided with the driving means 30 was not provided on the document table 3;
This may be provided on another three-dimensional measuring member or may be provided at a location other than the three-dimensional measuring machine, and if necessary, the driving means may be provided on a stationary body outside the probe main body.

Furthermore, the measurement signal generator according to the present invention can be applied not only to a type of coordinate measuring machine in which the measurement signal generator is replaced automatically, but also to a type of coordinate measuring machine in which the measuring signal generator is manually replaced. It is not limited to the automatic feeding type as in the example, but may be a manual feeding type.

Furthermore, the measurement signal generator according to the present invention can be used in a three-dimensional measuring machine in which the measurement signal generator moves relative to the object to be measured, a three-dimensional measuring machine in which the object to be measured moves relative to the measurement signal generator, or both of these. It can be applied to a moving three-dimensional measuring machine, and if necessary, the three-dimensional measuring machine may be one in which the object to be measured placed on the stage and the measurement signal generator supported by the measuring machine body move relative to each other. .

In addition to the above, the measurement signal generator according to the present invention is applicable not only to three-dimensional measuring machines but also to two-dimensional and one-dimensional measuring machines.

[Effects of the Invention] According to the present invention, since the position changing mechanism and the drive means, etc. that constitute the probe attitude adjustment device are arranged separately and independently, they can be used for the next measurement process while the previous measurement process is being performed. It is possible to change the position of the probe of the measurement signal generator, which shortens the measurement work time and speeds up the work.
The number of measurement objects that can be measured with one measurement signal generator can be expanded, and the range of application of the measurement signal generator can be expanded.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a three-dimensional measuring machine in which a measurement signal generator according to the present embodiment is used, and FIG. 2 is a partial cross-sectional view showing the measurement signal generator. FIG. 3 is a diagram showing a state in which a measurement signal generator is supported by a probe stiffener provided in a measuring machine. 4...Measurement object, 10...Probe which is a measurement signal generator, 11... Measuring machine main body, 13... Probe stocker which is a stationary body, 15... Probe main body, 15
A...Shank portion, 16...Position changing mechanism, 17 River detection unit, 18...Measuring point, 29...Electromagnetic clutch, 30...Driving means, 31...Rotary encoder.

Claims (1)

[Claims] (1) A probe that comes into contact with the measurement surface of the object to be measured, and a support that allows the probe to change its posture due to the reaction force of the object to be measured, and to return to its original posture when the reaction force is removed. and a detection unit formed including a detection section that generates an output signal when a change in attitude of the measuring head occurs;
A probe body having a shank portion for attachment to the measuring instrument body, and a drive provided on another stationary body outside the probe body for forcibly changing the position of the probe with respect to the probe body. and a position change mechanism driven by means.