JPH06147894A - Level - Google Patents

Abstract

PURPOSE:To provide a level allowing the accurate measurement of the inclination of a plane to be measured with no read-out error and reduced fluctuation of measurement between individuals while relaxing restriction on the measuring place. CONSTITUTION:A pendulum 17 is suspended swingingly from a body block 11 having smooth surfaces 13A, 13B. A detector 21 for detecting inclination of the pendulum with respect to the body block in the form of electric signal, and a digital indicator for indicating a value pertaining to the inclination thus detected are also provided. Upon installation of the body block on the plane to be measured, the pendulum inclines with respect to the body block depending on the inclination of the plane to be measured. The inclination is detected by the detector in the form of an electric signal and then displayed on the digital display.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a spirit level. For example, the present invention relates to a level used when measuring the flatness of a surface plate or a ground surface, or when installing a machine tool horizontally.

[0002]

2. Description of the Related Art Conventionally, a bubble level is used to determine a horizontal plane and measure a slight inclination from the horizontal plane. The bubble level is a curved glass tube (bubble tube) that forms part of an arc with a relatively large radius, and contains alcohol or ether, which has high fluidity and is hard to freeze at low temperatures, and leaves only one small bubble. It is a structure in which it is sealed and then attached to a block with a flat bottom. When the bottom of the block is placed horizontally, the bubbles come to the top of the bubble tube, that is, the center of the arc. Therefore, with this position as 0 point, a scale for measuring the movement of the bubble is engraved on the bubble tube.

For example, when the flatness of a surface plate is measured using a bubble level, the bottom surface of the block is installed at a measurement point on the surface plate, and then the position of the bubble is read from a scale. Similarly, if the bottom surface of the block is installed at other measurement points and the position of the bubbles at each measurement point is read from the scale, the flatness of the surface plate can be measured based on these readings. . Also, when installing the machine tool horizontally, for example, by adjusting the height of each leg so that the position of the bubble is 0 point with the bottom surface of the block installed on the bed, etc. Can be installed in

[0004]

However, in the conventional bubble level, the position of the bubble must be visually read by the measurer in relation to the scale, and the reading is likely to be inaccurate and the measurer Individual differences easily occur. In addition, when reading, the measurement person has to look into the position just above the bubble tube to read the position of the bubble, which limits the measurement place. For example, in a place where a relatively large space cannot be secured above the position where the block is installed, the measurer cannot look directly above the bubble tube. It has the drawback of being limited to places where a large space can be secured. Further, structurally, the structure is such that the inclination from the horizontal plane is measured from the position of the bubble that moves inside the bubble tube forming a part of an arc, so only a slight inclination can be measured.
That is, there is a drawback in that the inclination measuring range is narrow.

The object of the present invention is to eliminate all the above-mentioned drawbacks of the prior art, to accurately measure the inclination of the surface to be measured without any reading error and without individual differences, and at the measurement location. To provide a spirit level that is less restricted.

[0006]

In order to solve the above problems, a spirit level according to the present invention has the following structure. That is, the main body block whose bottom surface is formed as a smooth surface, the pendulum swingably supported by the main body block about an axis parallel to the smooth surface, and the inclination of the pendulum with respect to the main body block are detected as electric signals. The angle detection means and the display means for displaying the value relating to the inclination detected by the angle detection means.

[0007]

To measure the inclination of the surface to be measured, the bottom surface of the body block is installed on the surface to be measured. Then, the pendulum tilts with respect to the main body block according to the tilt of the surface to be measured. As a result, the tilt of the pendulum with respect to the main body block is detected as an electric signal by the angle detection means, and then displayed on the display means. Therefore, the measurer only has to read the display value displayed on the display means, and can accurately measure the inclination of the surface to be measured without a reading error and without individual differences. Moreover, since the display means can be located in a place where it can be easily seen by the measurer, there are few restrictions on the measurement place.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spirit level according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the spirit level of this embodiment. The spirit level comprises a spirit level main body 1 and a data processing device 3 which is connected to the spirit level main body 1 via a cable 2 and which processes an output signal from the spirit level main body 1 in a predetermined manner.

The spirit level body 1 is, as shown in FIG.
It has a rectangular parallelepiped-shaped metal main body block 11 having flanges on both sides of the bottom surface. In the main body block 11, smooth surfaces 13A and 13B are formed on both sides sandwiching an inverted V groove 12 formed along the longitudinal direction of the bottom surface, and open from the top surface to the bottom surface at an intermediate position in the longitudinal direction. A rectangular through hole 14 is formed. In the through hole 14, a rotary shaft 16 is provided in parallel with the smooth surfaces 13A and 13B via bearings 15A and 15B and the main body block 1 is provided.
1 is rotatably supported along the width direction. An upper end of a pendulum 17 having a fan portion 18 at its lower end is fixed to the rotary shaft 16.

As shown in FIG. 3, the fan portion 18 of the pendulum 17 has a heavy weight 1 made of lead having a large specific gravity on one side surface.
9 is attached, and a reflection type main scale 20 in which an optical grating is arranged in a fan shape around the rotation axis 16 is attached to the opposite side surface thereof.
On the side wall of the through hole 14 facing the main scale 20,
A detector 21 that constitutes an angle detecting means together with the main scale 20 is attached to the main scale 20 with a predetermined gap. Like the main scale 20, the detector 21 includes an index scale 22 in which reference optical gratings are aligned in a fan shape, a light source (not shown) for irradiating the scales 20 and 22 with light, and light reflected by the main scale 20. A photoelectric conversion element (not shown) for converting into an electric signal is included, and the inclination of the pendulum 17 with respect to the main body block 11 is output as an electric signal.

As shown in FIG. 4, the data processing device 3 includes a signal processing circuit 31 for processing the output signal from the detector 21, and a counter 32 for counting the pulses from the signal processing circuit 31. A counter control circuit 33 that sets the count number of the counter 32 to 0 or 1/2, an averaging circuit 34, and a display mode conversion circuit 35.
And a switch 36 for switching the outputs from the counter 32, the averaging circuit 34 and the display mode converting circuit 35,
It comprises a digital display 37 for digitally displaying the data given through the switch 36. Each of these circuits is housed in a housing 38 (see FIG. 1).

Although not shown, the signal processing circuit 31 includes a waveform shaping circuit for shaping the output signal from the detector 21 into a rectangular wave, a dividing circuit, a rotation direction discriminating circuit, etc., and a tilt direction of the pendulum 17. The number of pulses corresponding to is output in the number corresponding to the tilt angle of the pendulum 17 with respect to the main body block 11. The counter control circuit 33 includes the housing 3
When the zero set key 41 provided on the front face of 8 is pressed, the count number of the counter 32 is set to 0,
When the set key 42 is pressed, the count number of the counter 32 is set to ½ thereof.

The averaging circuit 34 inverts the counting operation of the counter 32 (that is, from addition to subtraction, subtraction from addition, provided that the averaging key 43 provided on the front surface of the housing 38 is pressed. The peak value when inverted to addition) is taken in a preset number of times (for example, 6 times), the final tilt angle is estimated by adding these count numbers, and then the tilt angle is digitally displayed through the switch 36. It is displayed on the device 37. The display mode conversion circuit 35
Is provided on condition that the display mode switching key 44 provided on the front surface of the housing 38 is pressed.
The count number (inclination angle) is converted into a height H per 1 m, which is displayed on the digital display 37 through the switch 36. In FIG. 1, reference numeral 45 is a power on / off switch.

Next, the operation of this embodiment will be described. For example, in order to measure the flatness of the surface plate, after installing the smooth surfaces 13A and 13B of the main body block 11 at the measurement points on the surface plate, it is confirmed that the pendulum 17 is stationary and the zero set key 41 is pressed. Push. Then, the counter control circuit 33
Sets the count number of the counter 32 to zero. As a result, “0” is displayed on the digital display 37. Therefore, thereafter, this measurement point becomes the reference plane.

Next, when the smooth surfaces 13A and 13B of the body block 11 are installed at other measurement points on the surface plate, the pendulum 17 tilts with respect to the body block 11 according to the inclination of the measurement point with respect to the reference plane. . Then, the main block 1
The inclination of the pendulum 17 with respect to 1 is detected by the detector 21, and the signal processing circuit 31, the counter 32, and the switch 3 are detected.
6 is displayed digitally on the digital display 37.
Therefore, if the display value of the digital display 37 is read, the inclination with respect to the reference plane can be known.

At this time, the display on the digital display 37 is changed to 1
When it is desired to display the height H per m, the display mode switching key 44 is pressed. Then, the display mode conversion circuit 3
In 5, the count number (tilt angle data) of the counter 32 is fetched, the data is converted into the height H per 1 m, and then the data is displayed on the digital display 37 through the switch 36. When the display mode switching key 44 is pressed again, the count number of the counter 32 remains unchanged.
6 is displayed on the digital display 37. Therefore,
The inclination of the measurement point can be selectively switched and displayed by both the angle and the height H per 1 m.

When the smooth surfaces 13A and 13B of the main body block 11 are installed at the measurement points on the surface plate, the pendulum 17 swings about the rotary shaft 16 and it takes time for the pendulum 17 to stand still. There is. Alternatively, the pendulum 17 may not be completely stationary due to a slight vibration from the outside. In such a case, the averaging key 43 is pressed. Then, in the averaging circuit 34, the peak value when the counting operation of the counter 32 is inverted is fetched by a preset number of times (for example, 6 times), and the final tilt angle is estimated by adding these count numbers. After that, the tilt angle is displayed on the digital display 37 through the switch 36.

For example, it is assumed that the count of the counter 32 gradually converges to a certain value as shown in FIG. 5 due to the swing of the pendulum 17. At this time, in the averaging circuit 34, the peak value C ₁ when the counting operation of the counter 32 is reversed under the condition that the averaging key 43 is pressed.
To C ₆ are sequentially taken in, these values C _{1 to} C ₆ are added to estimate the final tilt angle, and then the tilt angle is switched by the switch 36.
Through the digital display 37. Therefore, even if the pendulum 17 takes a long time to stand still or the pendulum 17 is not completely stopped due to external vibration or the like, it is possible to immediately read the inclination of the measurement point with respect to the reference plane simply by pressing the averaging key 43. it can.

Regarding the position of absolute horizontal 0 degree,
Although it is set correctly at the time of shipment from the factory, if the absolute horizontal position is 0 ° due to aging or carelessness during handling, make the following adjustments. First, after mounting the main body block 11 on the surface plate, the zero set key 41 is pressed to set the count number of the counter 32 to zero. Next, turn over the main body block 11 (turn over both ends in the longitudinal direction so that they are in mutually opposite positions)
Then, after setting it on the surface plate, press the 1/2 set key 42. Then, the counter control circuit 33 causes the counter 32 to
Set the count number of to 1/2. That is, it is halved of the current count number. As a result, thereafter, the tilt angle of the pendulum 17 can be displayed with this point as absolutely horizontal 0 degree.

Therefore, according to this embodiment, the main body block 11 is swingably supported by the rotary shaft 16 as a fulcrum, and the detector 21 for detecting the angle of the pendulum 17 as an electric signal is provided. Since the data processing device 3 for processing the output signal from the detector 21 by predetermined processing and digitally displaying it is provided, when the main body block 11 is installed on the surface to be measured, the pendulum 17 is moved to the main body according to the inclination of the surface to be measured. The inclination of the pendulum 17 with respect to the block 11 is detected by the detector 21 as an electric signal and then displayed on the digital display 37, so that the inclination of the surface to be measured can be read without error and without individual differences. Can be measured accurately.

The level 2 main body 1 installed on the surface to be measured and the data processor 3 having a digital display 37 for displaying a value obtained by subjecting the output signal from the level level main body 1 to a predetermined process are connected to the cable 2. Since the connection is made via the measuring instrument, the measurer can read the value of the digital display 37 at a place distant from the position where the level body 1 is installed. Therefore, a relatively large space is provided above the position where the level body 1 is installed. The inclination can be measured even in a place where the angle cannot be secured. That is, it is possible to relax the restriction on the measurement place.

Further, since the heavy lead 19 made of lead is attached to the fan portion 18 of the pendulum 17, the pendulum 17 can be brought to a stationary state more quickly by the action of the heavy lead 19, so that an efficient measurement can be performed. Moreover, averaging key 4
On condition that 3 is pressed, the final tilt angle of the pendulum 17 is estimated from the peak value of the counter 32, and the tilt angle is digitally displayed on the digital display 37.
Since 4 is provided, the inclination of the surface to be measured can be immediately read even when it takes time for the pendulum 17 to stand still or when the pendulum 17 is not completely stopped due to external vibration.

Further, provided that the display mode switching key 44 is pressed, a display mote conversion circuit 35 for converting the tilt angle of the pendulum 17 into the height H per 1 m and digitally displaying it on the digital display 37 is provided. Therefore, the inclination of the measurement point can be selectively switched and displayed by both the angle and the height H per 1 m. Furthermore, 1/2 set key 4
Since the counter control circuit 33 that halves the count number of the counter 32 is provided on condition that 2 is pressed, it is possible to easily readjust the absolute horizontal 0 degree.

The spirit level of the present invention is not limited to the above embodiment, but includes the following modifications. For example, if the data processing device 3 is integrated into the spirit level body 1, it is convenient to carry. Moreover, if the main body block 11 constituting the spirit level main body 1 is composed of a ceramic base and a synthetic resin cover, the weight can be reduced,
More convenient to carry. In addition, if the mounting position of the digital display 37 is arranged at the position where the measurer can easily see,
There are no restrictions on the measurement location.

Regarding the angle detecting means, the photoelectric detector 2 including the scales 20 and 22 described in the above embodiment is used.
The number is not limited to 1, and any of capacitance type and magnetic type may be used as long as the inclination of the pendulum 17 with respect to the main body block 11 can be detected as an electric signal. Further, the display means is not limited to the digital display, and may be a meter type that reads the angle from the shake of the pointer and the scale.

[0026]

As described above, according to the spirit level of the present invention,
It is expected that the inclination of the surface to be measured can be accurately measured without any reading error and without individual difference, and that the measurement place is not limited.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a block diagram showing a circuit configuration of a data processing device in the embodiment.

FIG. 5 is a diagram showing how the pendulum in the above-described embodiment converges to a certain value while swinging.

[Explanation of symbols]

 1 leveler main body 2 data processing device 11 main body block 13A, 13B smooth surface 16 rotary shaft 17 pendulum 20 main scale 21 detector 22 index scale 37 digital display.

Claims (1)

[Claims] 1. A body block having a bottom surface formed into a smooth surface, a pendulum swingably supported by the body block about an axis parallel to the smooth surface, and an inclination of the pendulum with respect to the body block. A spirit level, comprising: angle detecting means for detecting as a signal; and display means for displaying a value relating to the inclination detected by the angle detecting means.