JPS60210701A - Measuring apparatus for curved surface - Google Patents

Abstract

PURPOSE:To make an apparatus easy to operate, highly reliable and capable of performing a number of measurements in a short time, by conducting measurement automatically at a number of points after an object to be measured is set. CONSTITUTION:After an object 10 to be measured is mounted on a sample table 42 at a mounting position A, a driving motor 48 is started to move the object horizontally to a measuring position B and a sliding base 44 is fixed by a positioning block 54. Next, a detecting unit 14 is lowered by an air pressure cylinder 28, so as to make the fore end of a detector 12 contact with the curved surface of the object. When the unit 14 is lowered to a prescribed position, an integrated operation processor is driven to conduct measurement. The determination as to whether the result of measurement is acceptable or not is made by a method wherein the difference from a reference value at each measuring point is calculated, the mean square deviation of errors in the number of N is found and it is determined whether said deviation exceeds preset limits or not. When the deviation exceeds the limits, it is displayed in a display unit that the result is not acceptable, and the measurement is ended.

Description

[Detailed description of the invention] The present invention relates to a curved surface measuring instrument.

Conventionally, three-dimensional measuring machines have been mainly used as devices for measuring three-dimensional curved shapes such as spherical surfaces and paraboloids.

This measuring machine uses measuring point detectors for mutually orthogonal x, y,
The curved surface shape can be measured by moving it in the z-axis direction and directly displaying the measurement position digitally, or by performing arithmetic processing using a computer.

However, in general, when measuring a curved surface, the curved surface is determined by measuring multiple points instead of measuring one point. Therefore, in the above-mentioned measuring device, it is necessary to repeat a large number of measurements by fixing the detector at each measurement point along each axis, or one of the axes, and moving it along the other axis.

For this reason, it takes time to measure and also requires precision in each axis, making it expensive.

By the way, with the recent practical use of communication satellites, it has become possible for each household to receive satellite communication broadcasts, and relatively small-diameter parabolic antennas for receiving these broadcasts have been provided.

In a parabolic antenna, radio waves received by a parabolic main reflector are reflected back toward the main reflector by a sub-reflector located at the focal point, and are received by a receiver attached to the main reflector.

Therefore, the function of the main reflector, which receives the received radio waves first, is extremely important in receiving the received radio waves, and particularly its curved surface requires strict accuracy control.

On the other hand, there is a strong demand for this type of parabolic antenna to be mass-produced to reduce costs, otherwise it would not be popular for household use.

Taking these conditions into consideration, the above three-dimensional measuring machine was not suitable due to the problems mentioned above.

Therefore, the inventors of the present invention investigated existing measuring devices and measuring methods.

First, for measuring spherical surfaces, there is a measuring device called a spherical finger that has three legs at the center and outside, but this cannot be used for parabolas.

In addition, for example, in the case of a spherical mirror, measurement can be performed by an optical method, but parabolic antennas usually have a metal surface coated with paint, and this method cannot be used because the reflectance is poor.

Furthermore, a method using radio wave characteristics may be considered, but in this case, it is necessary to increase the gap between the antenna and the transmission source, resulting in an increase in the size of the device.

As described above, there has been no device available that can measure the curved surface of a mass-produced parabolic antenna, for example, 10 curved surfaces with relatively high accuracy and in a short time.

The present invention has been made in view of this background, and its purpose is to provide a curved surface measuring device that is easy to operate, highly reliable, and capable of performing a large number of measurements in a short period of time. It is in a place where we provide.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of a curved surface measuring device according to the present invention.

FIG. 1 shows the overall configuration of the device, which includes a plurality of detectors 12, which abut a predetermined position of a measurement object 10 having a curved surface, such as a parabolic antenna, and convert the depth into an electrical signal. 12..., and the measuring object 1
A detection unit 14 that moves up and down directly above 0 sequentially compares the output signal of the detector 12 with a reference value,
It is generally composed of a comparison/discrimination means 16 that determines the quality of the object to be measured, and a moving positioning unit 18 that detachably holds the object 10 to be measured and moves it horizontally to just below the detection unit 14.

The detector 12 is, for example, a linear displacement potentiometer, and each detector 12, 12, etc. uses, for example, a plurality of standard scales with different thicknesses to calculate the difference between the amount of displacement and the depth. Calibrate the relationship, find a relational expression, store it in ROM (described later) or RAM backed up by a battery, read out this expression according to the displacement of each corresponding detector 12, and calculate the amount of displacement to the depth. Convert to

The detection unit 14 includes the above-mentioned detectors 12.12...
- A holding block 20 for fixing and holding the holder in a predetermined position via the mounting beam 19, and a base 22 for holding the holding block 20.
The holding block 20 is supported by a plurality of guide shafts 24, 24 installed vertically, and a coil spring 26 is attached to each guide shaft 24. The reaction force of the pneumatic cylinder 28 is secured by a reaction force receiver 30 erected on the base 22.

The comparison and discrimination means 16 includes detectors 12, 12, . . .
A stepping relay 32 has contacts that are individually connected to ... and a movable contact that sequentially scans these contacts, and sequentially extracts the output signals of the detector 12, and converts the extracted signals into pulse signals. An A/D converter 34, an integrated processing device 36 which inputs the signal through an interface 35, compares it with a preset reference signal, and performs arithmetic processing based on this signal, and a processing result. Printer 38 for recording. and a display unit 40 that displays the determination of the processing results.

The centralized freezing calculation processing unit [36 is a so-called personal computer, which includes a CPU 36a, a RAM 36b, an RO
It consists of M36c and I10 boat 36d.

Note that reference numeral 36e shown in the figure is a drive circuit for the stepping relay 32, which is controlled by the CPU 36a.

On the other hand, the movable positioning unit 18 includes a sample stage 42 for fixing the measurement object 10 in a fixed position, and a sliding base 44 on which the sample stage 42 is placed and horizontally moved from the mounting position 11A of the object 10 to the measurement position 1tB. It has

The sliding base 44 extends through the base 22.
This base 4
A rack 52 that meshes with a pinion 5° attached to a rotating shaft of a drive motor 48 protruding downward from the base 22
In addition, the base 22 has a mounting number marked with a positioning block 54, 54' that locks the sliding base 44 at the installation position @A and the measurement position fffB to accurately position and fix it. .

As shown in FIG. 3, the measuring device configured as described above first mounts the object 10 to be measured on the sample stage 42 to the mounting position, starts the driver 48, and moves it to the measurement position. f
B, that is, horizontally moved to just below the detection unit 14,
The sliding base 44 is fixed by a positioning block 54.

The detection unit 14 is then lowered by the pneumatic cylinder 28.

This operation is performed by the holding block 20 being lowered by its own weight due to the exhaust of the pneumatic cylinder 28, but it is preferable that the cylinder 28 is exhausted at a slow speed in order to prevent a sudden descent.

Further, just before the tip of the detector 12 comes into contact with the curved surface of the measurement target 10, a coil spring 26 attached to the guide shaft 24
It is designed to have flexible contact due to its elasticity.

When the detection unit 14 descends to a predetermined position, the centralized processing unit @36 is activated.

The operating procedure of this device 36 is performed according to the flow shown in FIG. 4. First, when the power is turned on, the stepping relay 32 and the interface 35 are initialized (step 2).

Then, while reading the measured value from the detector 12 (step ■), comparing it with a reference value that varies depending on each measurement point (step ■), and switching the stepping relay 32, the number of measurement points (N) is increased. Repeat step (2), pass/fail judgment (step (2)), and end.

Judgment of pass/fail is made by, for example, calculating the difference from the reference value at each measurement point, calculating the mean square deviation of the N errors, and checking whether this exceeds a preset range. A message indicating that the test has failed is displayed on unit 40.

When the measurement is completed in this way, the holding block 20
is raised to the top dead center of a predetermined stroke by the operation of the pneumatic cylinder 28, the sliding base 44 and the positioning block 54 are unlocked, and the sample stage 42 is horizontally moved to the mounting position 11A of the measurement object 1o. move and fix the sliding base 44 with the positioning block 54' (the object to be measured 10
to complete one measurement cycle.

Note that from the start of the drive motor 48 described above, the mounting position A
If the series of operating procedures for the apparatus to return to the previous point are stored in advance in the ROM 36C and the sensors are placed at appropriate locations, it is possible to automatically perform operations other than the attachment and detachment of the measurement object 10.

In addition, the arrangement of the detectors 12, 12, etc. is selected appropriately in consideration of the measurement points. For example, when the curved shape of the object to be measured 10 is axially symmetrical, The mounting beams 19 are arranged along a plurality of axes forming an angle of , and the detector 12 is mounted at a predetermined location on each axis.

As described above in detail in the embodiments, in the curved surface measuring device according to the present invention, compared to conventional three-dimensional measuring devices, after setting the measurement target 10, it is possible to operate the switch or Since it can automatically measure multiple points, it is extremely easy to operate, and since it eliminates human intervention except for IIIR, it achieves uniformity and homogenization of measurements, greatly increasing reliability. improves.

In addition, since the installation space is small and the measurement time is short, it is also suitable for measuring curved surfaces of items that are mass-produced, such as parabolic umbilical cords.

[Brief explanation of the drawing]

FIG. 1 is an overall explanatory diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram of the comparison and discrimination means, FIG. 3 is a flowchart showing the operating order of the device, and FIG. 4 is a flowchart of the central processing unit. be. 10... Measurement object 12... Detector 14... Detection unit 16... Comparison/discrimination means 18... Movement positioning unit 19.
... Mounting dome 20 ... Holding block 22 ... Base 24 ... Guide shaft 26
...... Coil spring 28 ... Pneumatic cylinder 30 ... Reaction force receiver 32 ... Stepping relay 34 ... A/D converter 36 ...Centralized processing unit 36. a...C
PLJ36b...RAM 360...ROM36d
...I10 boat 36e...drive circuit 38...
...Printer 40...Display unit 42.
...Sample stand 44...Sliding base 4
6...Rail 50...Pinion 54
・・・・・・Positioning block ゛Patent applicant: Ube Nitto Kasei Co., Ltd. Agent: Patent attorney - Kensuke Iro Figure 1

Claims (1)

[Claims] A detection unit that has a plurality of detectors that come into contact with a predetermined position of a measurement target having a curved surface and converts depth into an electrical signal, and that moves up and down directly above the measurement target, and the output signal of the detector and a reference. The method is characterized by comprising a comparison/discrimination means for sequentially comparing the values and determining whether the object to be measured is good or bad, and a moving positioning unit that detachably holds the object to be measured and horizontally moves it to directly below the detection device. Curved surface measurement equipment.