JPS61219820A - Digital display type measuring device - Google Patents

Abstract

PURPOSE:To obtain a power saving type measuring device having high accuracy, high resolving power and excellent handleability, by providing a pressure switch operated when an elastic member generates predetermined deformation and supplying power to a measuring means at the time of the operation of the pressure switch and forcibly setting a digital display device to a reference value. CONSTITUTION:A digital display board 21 is provided to a slider 2 and an encoder 23 for detecting the moving displacement amount of the slider 2 and displaying the same on the display board 21 is mounted in the slider 2. An elastic member 28 deformable to the moving direction of the slider 2 is provided to the surface of a finger hooking member 26 opposed to the slider 2. A change- over circuit 35 judges whether a reference value is set when a pressure switch 24B is turned ON in such a state that a power source of a measuring means 30 is closed by the turning-ON of a pressure switch 24A and, when said reference value is not set, a reference value setting 36 is selectively operated and, when set, a hold circuit 37 is selectively operated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a digital display type measuring instrument, and particularly to a caliper,
Stabilizing the measuring force and Can be used to reduce power consumption.

[Background Art and its Problems] Conventional measuring instruments, for example, the well-known caliper, which has a main scale with one measuring point and a slider with the other measuring point,
Digital display type measuring instruments have a built-in encoder that detects the amount of displacement of the slider, and the measured values detected by this encoder are digitally displayed on an integrated or separate display.They are highly accurate and easy to handle. It is used in most industrial fields due to its ease of use and other advantages.

However, this type of digital display type measuring instrument has a problem in that, because of its high precision and high resolution, it has a much greater influence on the measured value of the measuring force than a mechanical scale reading method. This problem is particularly serious when the measuring tip (jaw) is long, such as a caliper, because the bending is also weighted. In addition, if the material of the object to be measured is a soft material such as rubber or plastic, the object to be measured is easily deformed by the measurement pressure. There was a desire for a measurement method that would guarantee the measurement of

By the way, in establishing a measuring means that enables measurement with a constant measuring force, sacrifices such as reducing the functionality of the measuring device as a whole or limiting the manner of use must not be assumed. For example, if the measuring force is constant, This is because if the absolute origin for determining the measured value from the displacement detection signal at the time of displacement is fixed, comparative measurement will become impossible.

Here, the applicant recognized that one of the problems is that the absolute origin should be configured so that it can be set under the same pressure as the measuring force during measurement, regardless of the position of the probe. .

Furthermore, in order to establish the above-mentioned measuring device, it is necessary that this does not increase the power consumption. In particular, with portable measuring instruments that have a built-in power supply, frequently replacing the power supply reduces overall measurement work efficiency, while increasing the power supply capacity results in large size, making it inconvenient to carry. It is.

[Object of the Invention] The object of the present invention is to solve the above-mentioned conventional problems, and is to provide a high-precision, high-resolution, and easy-to-handle device that guarantees measurement work with a constant measuring force. The purpose of the present invention is to provide a power-saving digital display measuring instrument.

[Means and effects for solving the problems] The present invention has the following features:
With conventional measuring instruments, it is possible for the operator to determine the position of the probe in advance according to a certain measuring force and then stop the probe without applying a pressing force greater than the fixed measuring force to the object to be measured. Considering that handling is extremely difficult in practice, the system is configured so that it can automatically display the measured value at a variable predetermined measuring force if the same measurement work as in the case of conventional measuring instruments is performed. It is configured so that the absolute origin can be set at any position of the child, and it is possible to perform measurements with a predetermined measuring force without making any changes to the ergonomic work mode. The system is configured so that the shutdown can be performed automatically to solve the above problem.

Specifically, it includes a main body having one measuring element, and a movable member having another measuring element which is movably attached to the main body and is brought into contact between the measuring parts of the object to be measured together with the one measuring element. , a digital display type measuring instrument comprising an encoder for detecting the amount of displacement of the movable member and a measuring means having a digital display for digitally displaying the measured value detected by the encoder; A finger rest member is attached via an elastic member having deformation characteristics in the direction of movement of the movable member, and a pressure switch is provided that is activated when the elastic member undergoes a predetermined deformation, and when the pressure switch is activated, A power supply circuit for supplying power to the measuring means, a reference value setting circuit for forcibly setting the display value displayed on the digital display as a reference value, and holding the display value on the digital display. The present invention is characterized in that it is provided with a hold circuit for displaying the data as it is, and that the power supply circuit, the reference value setting circuit, and the hold circuit are automatically switched and operated according to a certain sequence.

[Example] FIG. 1 shows a digital display caliper according to this example. In the same figure, a main scale 1 as a main body has a slider 2 as a movable member movably mounted along its longitudinal direction. Gauge head attachment portions 3 are each integrally formed, and gauge heads 5A and 5B are removably attached to each gauge head attachment portion 3 via setscrews 4, respectively.

The probes 5A and 5B are composed of a mounting shaft 6 fixed to the probe mounting portion 3 via a set screw 4, and a jig and -7 integrally formed at the lower end of the mounting shaft 6. Strive-7
are mounted so that they can be approached and separated from each other on the same axis.

The slider 2 has the pair of measuring elements 5 on its front side.
A digital display 21 is provided to display the amount of movement between A and 5B as a digital value, and a digital display 21 is provided inside to detect the amount of displacement of the slider 2, that is, the amount of displacement of the other stylus 5B relative to one stylus 5A. A capacitance type encoder 23 is built in to display this on the digital display 21. Here, the encoder 23 and the digital display 21 constitute a measuring means 30 that reads the dimensions of the object to be measured from the amount of displacement of the slider 2.

Further, on the other end surface side of the slider 2, first and second pressure switches 24A are provided at positions in the vertical direction.

24B, and a finger hook member 26 which is movable with respect to the main scale 1 is connected to the main scale 1 via a wire rod 25 as a connecting means. On the surface of the finger hook member 26 facing the slider 2, the first. Second pressure switch 24A, 24
Elastic members 28 deformable in the moving direction of the slider 2 are provided at positions other than the first and second positions. An elastic member 28 is located at a position facing the second pressure switches 24A and 24B.
Pressure elements 27A and 27B such as bottles, buttons, or plungers are provided to actuate them according to the amount of deformation of the elastic member 28. It is made of a material that deforms when an external force is applied and returns to its original shape when the external force is removed. The wire rod 25 has both ends connected to the slider 2 and the finger hook member 26, and is made of a flexible material that can allow the elastic member 28 to deform. Further, each of the pressers 27A, 27B is housed in the finger hook member 26 so as to be movable forward and backward in the direction of movement of the slider 2, and is biased in the protruding direction by lever springs 29A, 29B.

Moreover, the distance between the pusher 27A and the first pressure switch 24A is smaller than the distance between the pusher 27B and the second pressure switch 24B. Therefore, as the first elastic member 28 is deformed, first the first pressure switch 24A is activated, and then the second pressure switch 24B is activated.

As shown in FIG. 2, the encoder 23 slides on a scale 31 provided along the longitudinal direction of the main scale 1, and sends an electrical signal indicating the amount of relative displacement between the main scale 1 and the slider 2. A detection unit 32 is provided for detecting as follows. The output signal from the detection unit 32 is processed by the signal processing circuit 33 and sent to the counting circuit 34 as an up or down signal UDS.
and is counted there. The count value of the counting circuit 34 is transmitted to the digital display 2 via the switching circuit 35.
1 to the display drive circuit 38 which drives the signal.

The switching circuit 35 determines whether a reference value has been set when the second pressure switch 24B is turned on while the first pressure switch 24A is turned on and the measuring means 30 is powered on. If the reference value has not been set, the reference value setting circuit 36 is selectively activated, and if the reference value has been set, the hold circuit 37 is selectively activated. The reference value setting circuit 36 displays a preset reference value (here, zero) on the digital display 21 via the display drive circuit 38, and thereafter displays the count value from this reference value on the digital display 21. to be displayed. Further, the hold circuit 37 holds the display value displayed on the digital display 21 and displays it as it is, and releases the hold in response to a hold release signal from the release circuit 39. The cancellation circuit 39 inverts the up or down signal UDS from the signal processing circuit 33,
That is, after a predetermined period of time has elapsed since the moving direction of the slider 2 was reversed, a hold release signal is applied to the hold circuit 37 to release the hold state.

Furthermore, power is supplied to these measuring means 30 by a power supply circuit 40. The power supply circuit 40 is turned on by the first pressure switch 24A to supply power to the measuring means 30, and is turned off by a cutoff signal from the automatic power cutoff circuit 41. Power automatic cutoff circuit 41
When the up or down signal UDS from the signal processing circuit 33 is not continuously applied for a certain period of time, a cutoff signal is applied to the power supply circuit 40 to turn it off.

Next, the measuring method of this embodiment will be explained with reference to FIG. During measurement, after positioning the reference body between the pair of measuring elements 5A and 5B, when the finger hook member 26 connected to the slider 2 is pressed to the left in FIG. 2 is also moved in the same direction. After the measuring tip 5B comes into contact with the reference body due to the movement of the slider 2, the finger hook member 26
When the slider 2 is pressed in the same direction, the slider 2 cannot move, so the pressing force of the finger hook member 26 causes the elastic member 28
begins to transform. As a result, when the elastic member 28 deforms by a predetermined amount, the first pressure switch 24A is first turned on by the presser 27A of the finger hook member 26. Then, the power supply circuit 40 is turned on.

As a result, the measuring means 30 is powered on, and the digital display 21 displays zero. Thereafter, the amount of displacement of the slider 2 is detected by the encoder 23 and is ready to be displayed on the digital display 21.

If the finger hook member 26 is further pressed in the same direction from this state,
The elastic member 28 is further compressed, and then the finger hook member 26
The second pressure switch 24B is turned on by the pusher 27B. When the second pressure switch 24B is turned on, the switching circuit 35 determines whether a reference value has been set.

In this case, since the reference value has not been set, the reference value (zero) preset in the reference value setting circuit 36 is displayed on the digital display 21 via the display drive circuit 38. In other words, the displayed value on the digital display 21 is forcibly cleared to zero regardless of the displayed content at that time. This sets the absolute origin.

After setting the absolute origin, once the slider 2 is moved to the right in the figure, the value displayed on the digital display 21 will increase from zero. , 5B, and then move the slider 2 again to the left in FIG. 1, the value displayed on the digital display 21 decreases.

Eventually, after both the probes 5A and 5B come into contact with the object to be measured, when the finger hook member 26 is further pressed in the same direction, the first pressure switch 24A is first turned on in the same manner as described above. However, at this point, the power has already been turned on, so the first
Even if the pressure switch 24A is turned on, there is no meaning at all.
Subsequently, the second pressure switch 24B is turned on. Then, in this state, the reference value has already been set, so
The hold circuit 37 then causes the digital display 21 to
The display value displayed on is held. Therefore, a measured value with the same measuring force as when setting the reference value, that is, zero, can be obtained.

After this, when the finger hook member 26 is moved to the right in FIG.
Since the output from the signal processing circuit 33 is inverted, that is, from a down signal to an up signal, the hold state by the hold circuit 37 is automatically released by a release signal output from the release circuit 39 after a predetermined time has elapsed since the inversion point. and ready for the next measurement.

On the other hand, during these steps, if the signal processing circuit 33 does not output an up or down signal for a certain period of time,
In other words, if the slider 2 does not move for a certain period of time, the automatic power cutoff circuit 41 is activated, and the power supply circuit 41 is activated by the cutoff signal.
0 is automatically blocked.

Therefore, according to this embodiment, the movement of the slider 2 is controlled by the finger hook member 26 connected to the slider 2 via the elastic member 28.
Since the impact force at the moment when both probes 5A and 5B contact the object to be measured is absorbed by the elastic member 28, the measuring force can be kept small even if the moving speed of the slider 2 is increased. It can be suppressed. Therefore, it is possible to work quickly, and since there is no bending of the probes 5A and 5B, there is no error caused by this, and even if the material to be measured is a soft material such as rubber, highly accurate measurement is possible. .

This means that even if the measuring device has a pair of measuring points 5A and 5B that can be detachably attached to the main scale 1 and slider 2, the measuring points 5A and 5B are positioned relative to the main scale 1 and slider 2. Accurate measurement values are always obtained without the problem of misalignment.

By the way, the structure is such that the probes 5A and 5B can be exchanged, which means that the probes 5A and 5B can be used to match the shape of the measuring part.
If you select , you can measure any special shape with one measuring device, and in addition to measuring the outer diameter described in the above example, you can also measure various dimensions of female threads, over-pressure diameter of gears, or shafts. The dimensions of the fillet can be accurately measured without the need for searching or multiple measurements.

For example, as shown in FIGS. 4 and 5, the gauge heads 15A and 15B for measuring female threads are attached to the gauge head attachment part 3, the finger hook member 26 is positioned on the inner end surface side of the slider 2, and the finger hook member 26 By moving the slider 2 to the right in FIG. 4 through the screws, various dimensions of the female thread can be measured. The probes 15A and 15B in this case are composed of a mounting shaft 16 that is attached to the probe mounting portion 3, and a contact portion 18 that is integrally formed at the lower end of the mounting shaft 16 and has a male threaded portion 17 on the outer peripheral surface. There is.

In addition, when the second pressure switch 24B is turned on, that is, when the deformation of the elastic member 28 reaches a predetermined amount, the hold circuit 37 is activated, so that if you perform the same measurement work as before, the pressure will always be constant. It is possible to take measurements with a measuring force of .

Furthermore, by turning on the second pressure switch 24B, the reference value setting circuit 36 and the hold circuit 37 are selectively activated, so that the measured pressure at the time of reference value setting and the actual measurement of the object to be measured can be changed. Since the measurement pressures are the same, both can be measured under the same measurement conditions, and from this point of view as well, highly accurate measurement is possible.

Furthermore, since switching between the reference value set circuit 36 and the hold circuit 37 is automatically performed by the switching circuit 35, there is no need to provide a switch or the like for switching, and therefore, handling is easy.

In addition, the first pressure switch 24A is activated before the second pressure switch 24B, and the power supply circuit 40 is turned on by turning on the first pressure switch 24A, so that the power supply circuit 40 is turned on from the beginning. Saves electricity compared to leaving it alone. In addition, when the signal processing circuit 33 does not output the up or down signal UDS for a certain period of time, the automatic power cutoff circuit 41 turns off the power supply circuit 40, so even if you forget to turn off the power switch after finishing work, No power is wasted, so it is particularly suitable for portable measuring instruments with a built-in power supply.

In addition, since the display hold state is not released until a predetermined period of time has elapsed after the output from the signal processing circuit 33 is reversed, the display value can be easily retrieved and displayed even in measurement positions or measurement locations where the display is difficult to see. It can be confirmed.

In addition, structurally, it is possible to add some components without making any major changes to the conventional caliper structure.
It is extremely simple and inexpensive.

In addition, in practice, if the elastic member 28 can be replaced with one having desired elastic characteristics, the optimum measuring force can be selected depending on, for example, the material of the object to be measured. Furthermore,
The pressers 27A and 27B provided on the finger hook member 26 and the first
．． If the distance between the second pressure switches 24A and 24B is configured to be adjustable, problems caused by fluctuations in sliding resistance between the main scale 1 and the slider 2 over time can also be eliminated. Therefore, if these functions are provided, it is extremely easy to establish a measuring device of the replaceable probe type.

Moreover, if the wire rod 25 is set with some play between the slider 2 and the finger hook member 26, the elastic member 25 will be
8 and does not cause damage to the object to be measured or the measuring instrument.

Further, in the above embodiment, two pressure switches 24A, 2
Although 4B are provided, these can also be performed by one switch. In this case9, for example, when the pressure switch is turned on for the first time, the power is turned on and the reference value is set at the same time, and when the pressure switch is turned on from the second time onward, the measured value is held. Any device may be used as long as it operates during the pressing operation of the finger hook member 26, and for example, a strain gauge or the like may be used. Moreover, the first. Second pressure switch 24A, 2
When the 4B is activated, a sound can be emitted, for example, by a buzzer, so that the operator can be auditorily informed of the time point at which the measured value is to be read.

Further, in the above embodiment, display hold release and power off are automatically performed based on the up or down signal from the signal processing circuit 33. However, for example, a hold release switch and a power off switch may be provided separately. In addition, for hold release, a release signal may be output to the hold circuit 37 when the output from the signal processing circuit 33 is inverted. Alternatively, the hold state may be maintained until the next hold timing and the display value may be updated to a new display value at the next hold time.

Furthermore, if a preset means for setting a reference value is provided, and an arbitrary reference value can be preset in the reference value setting circuit 36, absolute measurement is also possible.

Further, the encoder 23 is not limited to the capacitance type encoder described in the above embodiment, but may be any type such as photoelectric type, contact type, electromagnetic type, etc. In short, the amount of movement displacement between the main scale l and the slider 2 Any material that can be electrically detected is sufficient.

Furthermore, the present invention is not limited to the digital display type caliper described in the above embodiments, but can be applied to general digital display type measuring instruments such as micrometers and depth gauges.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a power-saving digital display type measuring instrument that guarantees measurement with a constant measuring force, has high accuracy, high resolution, and is excellent in handling.

[Brief explanation of the drawing]

Fig. 1 is a front view showing one embodiment of the present invention, Fig. 2 is its circuit diagram, Fig. 3 is an explanatory diagram of its operation, Fig. 4 is a front view with different probes attached, and Fig. 5 is 5 is a sectional view taken along the line v-V in FIG. 4. FIG. ■...Main scale as main body, 2...Slider as movable member, 5A, 5B...Measuring head, 21...Digital display, 23...Encoder, 24A, 24B...
- First and second pressure switches, 25... Wire rod as connecting means, 26... Finger hook member, 27A, 27B...
Presser, 28... Elastic member, 30... Measuring means, 3
6...Reference value set circuit, 37...Hold circuit,
41...Power supply circuit.

Claims (5)

[Claims] (1) A main body having one measuring element, a movable member having the other measuring element which is movably attached to the main body and comes into contact between the measuring parts of the object to be measured together with the one measuring element; A digital display type measuring instrument comprising: an encoder for detecting the amount of displacement of a movable member; and a measuring means having a digital display for digitally displaying a measured value detected by the encoder, A finger rest member is attached via an elastic member having deformation characteristics in the direction of movement of the member, and a pressure switch is provided that is activated when this elastic member undergoes a predetermined deformation, and when this pressure switch is activated, the above-mentioned measurement is performed. a power supply circuit for supplying power to the means; a reference value setting circuit for forcibly setting the display value displayed on the digital display as a reference value; What is claimed is: 1. A digital display measuring instrument, comprising a hold circuit for displaying the display as it is, and configured to automatically switch and operate the power supply circuit, reference value setting circuit, and hold circuit according to a certain sequence. (2) In claim 1, the pressure switch includes a first pressure switch for operating the power supply circuit, and a second pressure switch for operating the reference value setting circuit and the hold circuit. A digital display type measuring instrument, characterized in that the first pressure switch operates before the second pressure switch as the elastic member deforms. (3) In claim 1 or 2, the power supply circuit is configured to be automatically shut off on condition that no up or down signal is output from the encoder for a certain period of time. A digital display type measuring instrument featuring: (4) In any one of claims 1 to 3, the finger hook member is movably attached to the main body, and the finger hook member is provided with a predetermined deformation of the elastic member and the elastic member. A digital display type measuring instrument, characterized in that it is provided with a pusher that activates the pressure switch when the pressure switch occurs. (5) In any one of claims 1 to 4, the finger hook member allows the elastic member to deform with respect to the movable member, and is attached to the main body integrally with the movable member. A digital display type measuring instrument, characterized in that the digital display type measuring instrument is connected by a connecting means movable along the axis.