JPS5967412A - Method and device for measuring displacement - Google Patents

Abstract

PURPOSE:To secure the reproduction of a reference position even when a power supply is interrupted, without limiting an effective stroke of a spindle, by a method wherein the position of the spindle just before it contacts with a shockabsorbing means is detected by a reference detecting means and a relative displacement amount is displayed by using this position as a reference. CONSTITUTION:A spindle 14 is actuated in the projecting direction by a draw spring 16. Immediately before the spindle 14 contacts with a cushion stopper 60 for regulating the miximum projecting position, columnar electrodes 74 and 76 of a reference position detector 64 and a spring board 70 fitted to a case 12 are disconnected through the intermediary of an engaging piece 78, and the position at this time is to serve as a reference for detecting positions of the spindle 14. The relative displacement of the spindle 14 from a reference position is displayed by a detector 20 consisting of an index scale 30, a light source and a photo-electric encoder containing a light-receiving element 30 and by a digital display unit. Accordingly, the reproduction of the reference position is secured even when a power supply is interrupted, and an effective stroke of the spindle is not limited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a displacement measuring method and apparatus, and in particular, a method for measuring the shape of a three-dimensional object by arranging a large number of contact type linear displacement measuring machines (hereinafter referred to as contact type gauges) in parallel. The tip of the spindle is attached to the main body case so that it can move freely in the axial direction, and the tip is protruding. The present invention relates to an improvement in a displacement measuring method and device that detects the amount of relative displacement and regulates the stroke of the spindle using a buffer means.

Conventionally, as a device for measuring the height or length of an object to be measured, as shown in FIGS. 1 and 2.

A main body case 12, a spindle 14 which is attached to the main body case 12 so as to be movable in the axial direction and whose tip 14a protrudes and is displaced by contacting the object to be measured, and the spindle 1.
4 in the projecting direction (downward in FIG. 1) to apply a measuring force, a stopper 18 to restrict the stroke of the spindle 14, and a displacement amount of the spindle 14. a detector 20 that detects and outputs it as an electrical signal, and a detector 20 that detects the relative displacement M of the spindle 14 from the reference position based on the electrical signal output from the detector 2o.
A digital display 22 is provided to detect and display the amount of relative displacement of the spindle 14 from the reference position when the tip of the spindle 14 comes into contact with the object to be measured. A so-called electric contact type gauge 10 is known.

In this electric contact type gauge 1o, the detector 20, for example, is gripped by the spindle 14 and moves together with the spindle 14.

A tie/scale 26 on which an optical grating is formed and a substrate 27
The tie/scale 2 on the main body case 12 side via
The tie/scale 26 and the index scale 28e are transmitted through the index scale 28, which is also provided with an optical grating and is mounted opposite the index scale 6, and the light source (not shown) located on the back side of FIG. A photoelectric molder/coder comprising a light receiving element 30 for detecting the brightness and darkness of the light is employed, and the relative displacement of the spindle 14 from the reference position detected by the photoelectric molder/coder is 11. is displayed digitally on, for example, a digital display 22. Note that, normally, a zero clear circuit including a zero set switch 32 is provided so that the digital display 22 can display zero at the period position.

(In the figure, 34 is a power switch, 36 is an AC power adapter used as needed, and 38 is a connection in the tJ\GA direction connected to the spindle 14.
This is a 9-turn +J-, second-turn guide for slidingly guiding the end opposite to the spindle 14 in a downward direction.

According to the above-mentioned contact type gauge IOK, its voltage #, ?
Pressing the zero set switch 32 unless it is shut off (1)
It has a feature in that a reference position set at an arbitrary position is set as zero, and the amount of relative displacement from the reference position is digitally displayed including the sign.

On the other hand, in recent years, with the development of applied technology for various measurements of the contact type gauges, as shown in FIG. Attempts have been made to compare and measure the shape of the three-dimensional object 54 placed on the object 520 with a reference object. However, if the conventional contact type gauge is used as is, the detector and digital display will be 1! It will be cleared to zero when the source is shut off. Therefore, even if the reference body is placed on the surface plate 52) and the reference position is set, if the power to the contact type gauge 10 is cut off when replacing the reference body with the object to be measured, each displayed value will change. Since the value becomes zero and the reference position of the contact type gauge 10 disappears, it is difficult to perform accurate comparative measurements.

Note that the contact type gauge 10 is normally provided with a stopper 18 for regulating the stroke of the spindle 14, so that the spindle 14 is at the maximum protrusion position V? ,
l! , t:J, referred to as the lower IH state) may be adopted as the reference position. However, in general, whether the detector is a photoelectric mold/coder or another type, it is necessary to provide a buffer at the end of the stroke due to the need for accuracy and to maintain the H of the measured object. Yes 1 Normally, this buffering means uses coil springs, rubber sections, etc. Therefore, the reproducibility of the maximum protruding position of the spindle 14 in the stationary state 9, is poor, and it is not possible to obtain the reproducibility of the μm order required for a linear gauge, for example.Therefore, the stationary state should be used as the reference position. was in trouble.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional art, and is capable of reliably reproducing the reference position even if the power is cut off, and furthermore, it is possible to achieve displacement that hardly limits the effective stroke of the spindle. The purpose is to provide a measuring method and device.

The present invention consists of: 1 a spindle tip attached to a main body case that is movable in the axial direction;
In a displacement measuring method in which the amount of relative displacement of the spindle from the reference position is detected when F abuts, and the stroke of the spindle is regulated by using a buffer means, The speed just before the means is activated/
The object C1 is achieved by making the dollar position the reference position.

The present invention mainly consists of a main body case, and a spindle which is movable in the axial direction and is attached to the main body case with a protruding tip, and which is displaced by coming into contact with an object to be measured.

A biasing means for biasing the spindle in the direction of protrusion j5 to add measurement 4j, and a buffer means for fully regulating the maximum protrusion position of the spindle, detect all displacement positions of the spindle, and In the displacement measuring device, the spindle includes a detector that outputs a total electric signal, and a display that displays the amount of relative displacement of the spindle from a reference position based on the electric signal output from the detector. By providing a reference position detecting means for detecting the position of the spindle immediately before the spindle comes into contact with the spindle, and by setting the spindle position @ all the reference positions when the reference position detecting means is activated, all of the above objectives 17 can be achieved. It is something that

Further, the reference position detecting means was attached to a temporary spring attached to the main body case, and also to the case.

an electrode piece that is in contact with the leaf spring when the spindle is not near the maximum protrusion position;

The spindle took 4=J. The reference position can be easily detected by 1F by comprising an engagement piece that breaks contact between the plate spring and the electrode piece at a position immediately before the slide/dol comes into contact with the buffer means.

In addition, the thickness of the leaf spring is made different between the support part and the tip part, so that the thickness of the tip part is smaller than that of the support part, so that the reference position can be raised without impeding the movement of the spindle too much. This allows for accurate detection.

Furthermore, the position of the electrode piece can be adjusted in the direction opposite to the axis of the spindle, so that the reference position can be adjusted.

Further, the buffer means is fixed to the main body case.

It has a cantilever-like thin-wall structure made of elastic parts, and has a simple structure, ensuring that high shock absorbing performance can be obtained without impairing the effective stroke of the spindle.

5. Embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 4 to 7, in this embodiment, a main body case 12 and a core main body case 12 are attached to the main body case 12 so as to be movable in the axial direction, and with the tip 14a protruding, and are displaced by contacting the object to be measured. a tension spring 16 that is stretched between a substantially central portion of the spindle 14 and the main body case 12 and applies a measuring force by urging the spindle 14 in the projecting direction; Cushion stopper 6 that also serves as a buffer means to regulate the maximum protrusion position
0, a cushion stopper 28 which also serves as a buffer means for regulating the maximum retracted position of the spindle 22, detecting the amount of displacement of the spindle 14 1-, and outputting this as an electric signal, the spindle 14. A main scale 26 attached to the main body case 12 side; In the contact type gauge 10, the contact type gauge 10 has a digital display (not shown) that displays the amount of relative displacement of the spindle 14 from the reference position based on an electric signal from the output J of the spindle 14. A reference position detector 64 is provided to detect the spindle position immediately before it contacts the cushion stopper 60 of the blade, and the spindle position ri when the reference position detector 64 is activated is set as the reference position. be.

The reference position detector 64 is connected to the substrate 68 by screws 66.
a leaf spring 70 whose one end is attached to the main body case 12 side, and the spindle 1 which is also attached to the main body case 12 side via an insulating bushing 72 and a board 68.
4 is not near the maximum protrusion position, the pair of cylindrical electrode pieces 74 and 76 that are in contact with the tip of the leaf spring 70 and the spindle 1 that is attached to the spindle 14 side
4 is comprised of a substantially inverted-shaped engagement pin 78 for breaking contact between the plate spring 70 and the electrode pieces 74, 76 at a position immediately before the electrode pieces 74, 76 come into contact with the lower cushion stopper 60.

The thickness of the plate spring 70 is different between the supporting part and the tip part, and the plate thickness of the tip part is smaller than that of the supporting part, so that the electrode; .76
The reproducibility of the position where contact is broken is very good.

Moreover, the position of the electric 1 restraint 4.76 is the same as that of the spindle 14.
The position can be adjusted in the axial direction, and the reference position can be easily adjusted.

Each of the cushion stoppers 60 and 62 is a single beam-shaped thin piece made of an elastic member 1, for example, rubber, with one arm fixed to the main body case 12. Therefore, a good damping effect can be obtained without substantially impairing the effective stroke of the spindle 14.

In the figure, 80 is a circuit board on which various electric circuits are arranged.

The action will be explained below.

When considering the case where a large number of contact type gauges 10 according to the present invention are fixed in parallel to a frame 50 to measure the shape of a three-dimensional object 1G, as shown in FIG. The displacement tl of the spindle 14 at that time is read from the gold digital display 22. At this time, the surface plate 5
2. Before placing the reference body on the second plate, if the voltage of each contact type gauge 10 is set to 1, the spindle 14 of each contact type gauge 10 is at its maximum protrusion position.

The reference position detector 64 will definitely operate.

Therefore, the dimensions of the reference body are measured based on the absolute reference position detected by the reference position detector 64.

Next, with the heavy bell shut off, the contact type gauge 12 is removed from the surface plate 52 along with the frame 50, and the object to be measured is placed on the surface plate 52. Furthermore, the frame 50 is attached to a surface plate 52.
Before returning to F, if the power to each contact type gauge 10 is turned on/off again, the spindle 1 of each contact type gauge 10 is
4 are at their maximum protrusion positions, the reference position detector 64 operates, and the contact type gauge 10 measures the displacement M' based on the absolute reference position. Therefore, even if the power to the contact type gauge is cut off when transporting the object to be measured or the contact type gauge, or if the power supply is cut off due to a power outage, operational error, etc.

It becomes possible to perform accurate comparative measurements based on the same absolute reference position.

In this embodiment, the reference position detector is provided near the maximum protrusion position of the spindle, so when the contact type gauge is in the measurement position, the displayed value is always calibrated at the absolute reference position. Therefore, #: Melon is reliably performed according to the reference position. Note that the method for obtaining the reference position is not limited to this, and it is of course possible to provide the reference position by providing a reference position detector near the maximum retracted position or near the center of the spindle, for example.

Furthermore, in this embodiment, a mechanical reference position detector consisting of a leaf spring, an electrode W, an engaging piece, etc. is used as the reference position detection means, so the structure is simple and the electric circuit side The burden is also small.

Note that the configuration of the reference position detection means is not limited to this,
For example, it is also possible to provide a scale stripe in the form of a hollow/dam pattern for detecting the absolute reference position in the middle of the main scale, and use the scale stripe to detect all reference positions.

In the embodiment 911, the present invention was applied to a contact-type linear displacement measuring machine including a detector having a photoelectric 1/coder, but the scope of application of the present invention is not limited to this, and the present invention is not limited to this. The present invention is similarly applicable to machines/coders other than Equation 1/coders, such as those including magnetic 1/coders, and displacement measuring devices other than linear displacement measuring machines. Furthermore, in addition to digital display, the present invention can be similarly applied to display of measurement results by pre-printing/printing or the like.

As explained below, according to the present invention, the reference position can be reliably reproduced even if the power is cut off, and the effective stroke of the spindle is hardly limited. have

[Brief explanation of the drawing]

Figure 1 is a front view showing a conventional contact type linear displacement measuring machine;
FIG. 2 is an enlarged front sectional view, FIG. 3M is a front sectional view showing an embodiment of the displacement measuring device according to the present invention, and FIG.
Similarly, FIG. 6 is a sectional view taken along line Vl--Vl in FIG. 4, and FIG. 7 is a sectional view taken along line 1--1 in FIG. 4. Type linear displacement measuring device 12...Body case 14...Spindle 16...Tension lever 20...Detector 60...Cut shift/stopper 64...Reference position detector 70...Plate spring 74.76... Electrode piece 78... Engagement piece. Fig. 4 Fig. 5 Tatami Fig. 6 Fig. 7

Claims (1)

[Claims] (It) Relative to the reference position of the spindle when the entire tip of the spindle attached to the main body case is movable in five axial directions and has a protruding tip, and comes into contact with the object to be measured. The displacement measuring method includes detecting the displacement M and regulating the stroke of the spindle using a buffer means, wherein the spindle position immediately before the buffer means operates is set as the reference position. 1. A displacement measurement method characterized by: (2) A main body case, which is freely movable in the axial direction in the non-stop case;
A spindle that is attached with a protruding tip and is displaced by coming into contact with an object to be measured, a biasing means for biasing the spindle in a protruding direction to apply an establishing force, and a maximum protruding position of the spindle. a buffer means for regulating the amount of displacement of the spindle; a detector that detects the amount of displacement of the spindle and outputs it as an electric signal; and an amount of relative displacement of the spindle from the reference position based on the electric signal output from the detector. In the displacement measuring device, the displacement measuring device has a reference position detecting means for detecting a spindle position immediately before the spindle comes into contact with the buffer means, and the spindle position when the reference position detecting means is activated is provided. A displacement measuring device characterized in that the reference position is set as the reference position. (3) The reference position detecting means is a leaf spring attached to the main body case, and the same is attached to the main body case. When the spindle is not in the vicinity of the maximum protrusion position, the electrode piece that is in contact with the leaf spring and the electrode piece that is attached to the spindle are connected to the leaf spring and the electrode at a position immediately before the spindle comes into contact with the buffer means. 3. The displacement measuring device according to claim 2, further comprising an engaging piece for breaking contact between the pieces. (4) The displacement according to claim 3, wherein the thickness of the leaf spring is different between the support part and the tip part, and the plate thickness of the tip part is larger than the plate thickness of the support part. measuring device. (5) The displacement measuring device according to claim 3, wherein the electrode piece is adjustable in position in the axial direction of the spindle. (6) The buffer means is fixed to one main body case. The displacement measuring device according to claim 2, which is a cantilever-like thin piece made of an elastic member.