JPH10227635A - Inclination sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inclination sensor that can be miniaturized and at the same time easily change a detection angle. SOLUTION: A liquid 13 and a gas 14 are sealed at a container 12 being formed in a dome by utilizing the difference in light transmittance between the liquid and the gas, infrared rays are applied from the top of the container 12 into the container 12, and at the same time reflection light from an incidence point is received. When a gas exists at the incidence point, a total reflection occurs at a boundary surface between the container 12 and the gas 14 and light reception output increases. When the gas 14 deviates from the incidence point, infrared rays are transmitted through the liquid 13 and nearly no reflection occurs and the light reception output decreases. An inclination angle can be determined by setting the size of the gas 14 so that the gas 14 deviates from the incidence point when the sensor body is inclined to a preset angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tilt sensor suitable for use in vehicles and the like.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing the structure of a tilt sensor disclosed in Japanese Patent Application Laid-Open No. 8-180780. This tilt sensor comprises a hemispherical container 1 having a circular opening 1a at the bottom, a sphere 2 placed in the container 1 and having a diameter larger than the diameter of the opening 1a of the container 1, and an opening of the container 1. 1
a photo-interrupter 4 comprising a light-emitting element 4a for irradiating the sphere 2 with light through the light-receiving element 4a and a light-receiving element 4b for receiving the reflected light from the sphere 2; This is to detect the angle. That is, when the container 1 is tilted and the sphere 2 comes out of the opening 1a of the container 1, light from the light emitting element of the photo interrupter 4 enters the container 1 and the output of the light receiving element 4b of the photo interrupter 4 sharply increases. descend.
As a result, the current inclination angle can be detected.

[0003]

However, the above-described conventional tilt sensor has the following problems.

First, since the sphere 2 cannot be fixed on the opening 1a of the container 1 unless it has a certain weight, there is a limit to the miniaturization of the sensor.

Second, since there are three factors that determine the detection angle, the size of the opening 1a of the container 1, the size of the sphere 2, and the weight of the sphere 2, fine adjustment is difficult. Could not be changed easily.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an inclination sensor which can be reduced in size and can easily change a detection angle.

[0007]

According to the present invention, a liquid and a gas are sealed in a container formed of a resin that transmits light, light is incident on the container, and reflected light at that time is detected. Things. In this case, the amount of the gas is made smaller than the amount of the liquid to form a bubble.

With this configuration, when the inclination angle of the container is 0 degrees, that is, when the container is in a horizontal state, the gas is necessarily located at the top of the container. And the output of the light receiving means for receiving the reflected light is increased. Then, when the container is inclined from this state and the gas moves from the top portion of the container, the light incident on the container passes through the liquid from the container, so that the output of the light receiving unit decreases.

As described above, by utilizing the difference in light transmittance between the liquid and the gas, it is possible to obtain a miniaturized tilt sensor unlike the one which projects light on the sphere 2 as shown in the conventional example. Becomes possible. Further, the detection angle can be arbitrarily set by adjusting the size of the gas. Further, by making the container for enclosing the liquid and the gas into, for example, a dome shape, it becomes possible to detect the inclination at an equal angle in any direction.

In order to achieve the above object, the tilt sensor according to the first aspect of the present invention is formed of a light-transmitting material, and has a container in which a liquid and a gas are sealed, and a light source for a predetermined position of the container. And light receiving means for receiving light reflected from a predetermined position of the container by the light emitted by the light emitting means.

[0011] The tilt sensor according to the second aspect of the present invention,
The container is formed in a dome shape.

According to the third aspect of the present invention, there is provided an inclination sensor,
A container that is formed into a cylindrical shape and a whole curved shape by a material that transmits light, and a container in which a liquid and a gas are sealed, and is provided at positions at the same distance on the left and right sides from the center of the container, respectively. A light projecting means for projecting light, and a sensor unit having a light receiving means for receiving light reflected from the container due to the light emitted by the light projecting means.

[0013] The tilt sensor according to the fourth aspect of the present invention,
The apparatus further includes a position changing unit that is provided for each of the two sensor units and changes a position of the sensor unit in a length direction of the container.

The tilt sensor according to the fifth aspect of the present invention provides
When a container is formed in a cylindrical shape and entirely curved by a material that transmits light, a reflective member is provided on the inner wall surface, and a liquid and a gas are sealed inside, and the container is in a horizontal state. First light receiving means provided in the container so as to be located on the gas in the container, and together with the first light receiving means when the container is tilted to one of the left and right predetermined angles. A second light receiving unit provided in the container so as to be located on the gas in the container, and a second light receiving unit provided at an end of the container on the second light receiving unit side;
Light projecting means for projecting light into the container.

[0015] The tilt sensor according to the sixth aspect of the present invention,
A container, which is formed in a cross shape and curved as a whole by a light transmitting material, is provided on each of four sides of the container in which a liquid and a gas are sealed, and projects light to the container. A light emitting means for emitting light; and a sensor unit having a light receiving means for receiving light reflected from the container by the light emitted from the light emitting means.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> FIG. 1 is a sectional view showing a first embodiment of an inclination sensor according to the present invention.

The tilt sensor 10 according to the first embodiment
Is a plate-shaped undercover 11, a dome-shaped container 12 fixed on the undercover 11, and a container 1
2 and liquid 13 and gas 14 enclosed in
Infrared light emitting diode (hereinafter LED)
15), a condensing lens 16 mounted on the front surface of the LED 15, a phototransistor 17 for receiving light reflected from the container 12, and a condensing lens mounted on the front surface of the phototransistor 17. 18 and
A light guide plate 19 attached to the top of the container 12 for guiding infrared light from the LED 15 to the container 12 and guiding reflected light from the container 12 to the phototransistor 17; a substrate 20 on which a circuit to be described later is mounted; And a fixing member 21 for fixing the phototransistor 17 and the substrate 20;
A body case 22 accommodating each of the above-described components;
The body case 22 includes a lead wire 23 that is electrically connected to the lead wire 0 and is drawn out of the body case 22, and a cover 24 that covers an upper end opening of the body case 22.

Each of the container 12 and the light guide plate 19 is made of a resin which transmits infrared light and has a small light loss. The LED 15 is disposed at a position where infrared light is incident on the vertex of the container 12 from an oblique direction. LED
The infrared light from 15 passes through the light guide plate 19 and then
Incident inside. The phototransistor 17 is disposed at a position for receiving reflected light generated at a boundary surface between the container 12 and the gas 14 when infrared light is incident on the container 12. In this case, as shown in FIG.
When it comes to the vertex of 2, the infrared light incident on the container 12 is totally reflected on the boundary surface between the container 12 and the gas 14, so that the output of the phototransistor 17 increases. On the other hand, when the gas 14 is off the vertex of the container 12, the infrared light incident on the container 12 passes through the liquid 13, so that the output of the phototransistor 17 is reduced. That is, as shown in FIG.
While the gas 14 is present above, the output of the phototransistor 17 increases because the infrared light from the LED 15 is totally reflected, and the infrared light from the LED 15 starts when the gas 14 deviates from the incident point 26. Is transmitted through the liquid 13, so that the reflection hardly occurs and the output of the phototransistor 17 is reduced.

As described above, the sensor body is inclined and the gas 1
The output of the phototransistor 17 becomes small when the point 4 deviates from the incident point 26. In this case, the inclination angle until the gas 14 moves off the incident point 26 varies depending on the size of the gas 14, so that the inclination angle to be detected can be easily changed by adjusting the size of the gas 14.

The circuit shown in the block diagram of FIG. 3 is mounted on the board 20. In this figure, the driving circuit 30
Pulse-drives the LED 15 so that the phototransistor 17 is not affected by external light, and
Amplifies the output of the phototransistor 17 to a predetermined level. The high-pass filter 32 removes a component due to external light in the amplified output of the phototransistor 17 and transmits only infrared light. The comparison circuit 33 is a high-pass filter 3
The output of the phototransistor 17 is compared with a predetermined reference value, and an H level signal is output when the output of the phototransistor 17 becomes equal to or less than the reference value. In this case, the reference value used in the comparison circuit 33 is the LED 15
Is a value corresponding to the output of the phototransistor 17 when the infrared light from the substrate is totally reflected at the interface between the container 12 and the gas 14. In the comparison circuit 33, a reference value can be set by a variable resistor.

In the tilt sensor 10 having such a configuration, when the tilt angle of the container 12 is within the detection angle, the gas 14 comes on the incident point 26. , And the output of the phototransistor 17 increases. When the container 12 is tilted from this state to the detection angle, the gas 14
Deviates from the incident point 26, the infrared light made incident on the container 12 passes through the liquid from the container 12, and almost no reflection occurs, so that the output of the phototransistor 17 is reduced.

As described above, the tilt sensor 10 according to the first embodiment utilizes the difference in the light transmittance between the liquid and the gas.
3 and the gas 14 were sealed, infrared light was made to enter the container 12 from the apex of the container 12, and the inclination angle could be detected by the presence or absence of reflected light from the incident point 26.

Accordingly, it is possible to obtain a tilt sensor which is smaller in size than the conventional tilt sensor which projects light onto the sphere 2. Further, the detection angle can be arbitrarily set by adjusting the size of the gas 14. Further, since the container 12 has a dome shape, the inclination can be detected at an equal angle in any direction.

<Second Embodiment> FIG. 4 is a sectional view showing a configuration of a second embodiment of the tilt sensor according to the present invention, and FIG. 5 is a tilt sensor of the second embodiment. A-
FIG. 3 is a sectional view taken along line A. The same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals.

The tilt sensor 40 of this embodiment is capable of detecting tilt angles in two directions, and is made of a resin having a small light loss transmitting infrared light and having a cylindrical shape and a curved shape as a whole. , A body case 42 supporting both ends of the container 41, and an under cover 4 used as a bottom plate of the body case 42.
3 and a container 4 used as a top plate of the body case 42.
1, the cover 41, the container 41, and the cover 4
4 and a sensor unit 45 interposed between the sensor unit 45 and the sensor unit 45.

The sensor units 45 are provided at the same distance from the center of the container 41 on both the left and right sides, respectively, and are respectively the same as those of the inclination sensor 10 of the first embodiment.
A slider 47 for holding the LED 15, the phototransistor 17, and the spring material 46 in addition to the ED 15, the phototransistor 17, the light guide plate 19, the substrate 20, and the lead wire 23.
It is composed of The light guide plate 19 is attached to the container 41. As shown in FIG. 5, a part of the slider 47 projects from the side opening 42A of the body case 42.
The projecting portion is supported by the side opening 42A of the body case 42. The slider 47 has a lower portion in the body case 42 supported by the container 41 and an upper portion supported by the cover 44 by a spring member 46.

The center portion of the spring member 46 is formed in a C-shape with a semicircular roundness, and the center portion is fitted into a concave portion of a moderating portion 44A formed in a wavy shape on the back side of the cover 44. The slider 47 is accommodated in the combined state.
In this case, in the state shown in FIG. 4, the central portion of the spring member 46 is fitted into the central concave portion of the detent portion 44A. The position of the sensor section 45 can be changed in three stages by the spring member 46 and the moderation section 44A of the cover 44. Then, to change the position of the sensor section 45, the knob 48 attached to the upper surface of the protruding portion of the slider 47 from the body case 42 is pulled in the length direction of the container 41. Sensor unit 45
, The detection angle can be changed without changing the size of the gas 14. That is,
When the sensor unit 45 is moved toward the center of the container 41, the detection angle is reduced, and when the sensor unit 45 is moved toward the end of the container 41, the detection angle is increased.

The tilt sensor 40 according to the second embodiment
Is capable of detecting the inclination angle in two directions having two sensor units 45, the sensor body is inclined rightward in the state shown in FIG. 4 and the left end of the gas 14 is the L of the left sensor unit 45.
When the infrared light from the ED 15 reaches the incident point on the container 41, total reflection occurs at the boundary surface between the container 41 and the left end of the gas 14, and the output of the phototransistor 17 of the sensor unit 45 increases. As a result, it can be seen that the sensor main body has tilted to a predetermined angle. In this case, as is apparent, the output of the phototransistor 17 of the sensor unit 45 is opposite to that of the tilt sensor 10 of the first embodiment described above. That is, in the tilt sensor 10 according to the first embodiment, the output of the phototransistor 17 decreases when the sensor body is tilted to a predetermined angle, but the tilt sensor 40 according to the second embodiment is The output of the transistor 17 increases. In this case, an inverting amplifier such as an inverter may be provided on the output side of the phototransistor 17 in order to make the tilt sensor 10 similar to the tilt sensor 10 of the first embodiment.

As described above, the tilt sensor 40 according to the second embodiment encloses the liquid 13 and the gas 14 in the cylindrical container 41 having a curved shape as a whole, and
Infrared light is made incident on the inside of the container 41 at the same distance on both the left and right sides from the center of 1 so that the inclination angles in two directions can be detected by the presence or absence of reflected light from each of the two incident points.

Therefore, it is possible to obtain a small-sized tilt sensor capable of detecting the tilt angles in two directions. Further, by changing the position of the sensor section 45 with respect to the length direction of the container 41, the detection angle can be set arbitrarily.

<Third Embodiment> FIG. 6 is a side view showing a configuration of a tilt sensor according to a third embodiment of the present invention.

The tilt sensor 60 of the third embodiment
Is such that the inclination angle in two directions can be detected in the same manner as the inclination sensor 40 of the above-described second embodiment, and the container 61 has the same shape as the container 41 of the inclination sensor 40. A mirror surface 62 as a reflection member is formed on the inner wall surface by aluminum evaporation or the like, and two phototransistors 17A are provided on the wall surface on the right side from the inner center.
17B, and an LED 15 is provided at the right end of the container 61.
Is provided. The phototransistors 17A and 17B are spaced apart from each other,
5 receives infrared light. Further, a liquid 13 and a gas 14 are sealed in the container 61.

In the tilt sensor 60 having such a configuration, the gas 14 comes to the center of the container 61 within the detection angle (± 5 degrees) as shown in FIG. LED to phototransistor 17A
No infrared light from 15 arrives. That is, the LED 15
Infrared light from the LED is totally reflected at the right end of the gas 14
Since it returns to the 15 side, it does not reach the phototransistor 17A, but only reaches the phototransistor 17B, and only the output of the phototransistor 17B increases. Thereby, it is understood that the inclination angle is within ± 5 degrees.

On the other hand, as shown in FIG. 6B, when the sensor body is inclined to the detection angle of +5 degrees, the gas 14 moves to the right side of the container 61, and the phototransistor 1
It comes to a position spanning both 7A and 17B. Thus, L
The infrared light from the ED 15 is supplied to the phototransistors 17A, 1
7B. Therefore, the outputs of the phototransistors 17A and 17B are both reduced.
This indicates that the inclination angle has become +5 degrees.

As shown in FIG. 6 (c), when the sensor body is inclined to the detection angle of -5 degrees, the gas 14 moves to the left side of the container 61 and the phototransistor 1
It comes to a position away from both 7A and 17B. As a result, the infrared light from the LED 15 is
A and 17B are reached. Therefore, the outputs of the phototransistors 17A and 17B both increase.
Thus, it can be seen that the inclination angle has become -5 degrees.

FIG. 7 is a block diagram showing a circuit of the tilt sensor 60 according to the third embodiment.

In this figure, the drive circuit 30 drives the LED 15 in pulses so that the phototransistors 17A and 17B are not affected by external light. Amplifier circuit 3
1A and 31B amplify the outputs of the phototransistors 17A and 17B to a predetermined level. High pass filter 32
A and 32B are amplified phototransistors 17A and 1B.
The component due to external light in the output of 7B is removed and only infrared light is transmitted. The comparison circuit 33 compares the output of the phototransistor 17A from the high-pass filter 32A with the output of the phototransistor 17B from the high-pass filter 32B. If the outputs of the phototransistors 17A and 17b are the same and small, a positive signal is output. Output. Also,
If the outputs of the phototransistors 17A and 17b are the same and large, a negative signal is output.

As described above, the tilt sensor 60 according to the third embodiment is formed in a cylindrical shape and a curved shape as a whole, and further has a mirror surface 62 made of aluminum vapor deposition or the like on the inner wall surface, and also has a center from the inner center. Two phototransistors 17A and 17B are provided on the wall on the right side.
The liquid 13 and the gas 14 are sealed in a container 61 provided with the phototransistor 15, and infrared light from the LED 15 is
By receiving light at A and 17B, the inclination angles in two directions can be detected.

Accordingly, it is possible to obtain a small tilt sensor capable of detecting the tilt angles in two directions. Gas 1
By adjusting the size of 4, the detection angle can be set arbitrarily.

<Fourth Embodiment> FIG. 8 is a perspective view showing an external configuration of a tilt sensor according to a fourth embodiment of the present invention.

The tilt sensor 70 of the fourth embodiment
Is a container 71 formed in a cross-shaped and entirely curved shape by a resin having a small light loss transmitting infrared light.
And a sensor unit 72 attached to each of the four sides 71A to 71D of the container 71 to allow infrared light to enter the container 71 and receive reflected light from the container 71 due to the incident infrared light. ing.

The sensor unit 72 includes the LED 15 similarly to the sensor unit 45 of the tilt sensor 40 according to the second embodiment.
And a phototransistor 17. Container 7
A liquid 13 and a gas 14 are sealed inside 1.

In the tilt sensor 70 having such a configuration, since the gas 14 does not reach any of the four sensor units 71 within the detection angle, the output of the phototransistor 17 of each sensor unit 71 is small. . In this state, for example, when the side 71C inclines to the detection angle, the gas 1
4 reaches an incident point (not shown) of the infrared light by the sensor unit 71 attached to the side 71C, the infrared light from the LED 15 of the sensor unit 71 is totally reflected on the boundary surface between the container 71 and the gas 14. The light is reflected and the output of the phototransistor 17 of the sensor unit 71 increases. Note that the outputs of the phototransistors 17 of the remaining three sensor units 71 remain small.

As described above, the tilt sensor 70 according to the fourth embodiment encloses the liquid 13 and the gas 14 in the container 71 formed in a cross shape and a curved shape as a whole.
Infrared light is made to enter the container 71 at each of the four sides of the container 1, and the inclination angles in four directions can be detected based on the presence or absence of reflected light from each of the four incident points.

Accordingly, it is possible to obtain a small tilt sensor 70 capable of detecting the tilt angles in four directions. Further, the detection angle can be arbitrarily set by adjusting the size of the gas 14. If the mounting position of each sensor unit 72 is shifted, the detection angle can be arbitrarily set without adjusting the size of the gas 14.

[0046]

As described above, according to the first aspect of the present invention, the liquid and the gas are sealed in the container by utilizing the difference in the light transmittance between the liquid and the gas, and the light is sealed in the container. And incident
Since the inclination angle is detected based on the presence or absence of the reflected light from the incident point, it is possible to realize an inclination sensor smaller than a conventional inclination sensor that projects light onto a sphere. Further, the detection angle can be arbitrarily set by adjusting the size of the gas.

According to the second aspect of the present invention, since the container has a dome shape, the inclination can be detected at an equal angle in any direction.

According to the third aspect of the present invention, a liquid and a gas are sealed in a cylindrically-shaped container which is formed into a curved shape as a whole, and light is emitted from the center of the container at the same distance on both the left and right sides. , And the inclination angles in two directions are detected based on the presence or absence of reflected light from each of the two incident points. Therefore, a small inclination sensor capable of detecting the inclination angles in two directions can be obtained.

According to the fourth aspect of the present invention, since the position of the sensor portion with respect to the longitudinal direction of the container can be changed, the detection angle can be arbitrarily set without adjusting the size of the gas. it can.

According to the fifth aspect of the present invention, the inner wall is formed into a curved shape as a whole, and the inner wall surface is subjected to a mirror surface treatment such as aluminum vapor deposition, and the first and second wall surfaces are shifted to the right from the inner center. Liquid and gas are sealed in a container provided with light receiving means 2 and light emitting means at the right end, and infrared light from the light emitting means is received by the first and second light receiving means. Since the inclination angles in the directions are detected, a small inclination sensor capable of detecting the inclination angles in two directions can be obtained.

According to the sixth aspect of the present invention, a liquid and a gas are sealed in a container formed in a cross shape and a curved shape as a whole, and light is incident on the four sides of the container 71 into the container. Since the inclination angles in four directions are detected based on the presence or absence of the reflected light from each of the four incident points, a small inclination sensor capable of detecting the inclination angles in four directions can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a tilt sensor according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of the tilt sensor according to the first embodiment.

FIG. 3 is a block diagram illustrating a circuit configuration according to the first embodiment.

FIG. 4 is a cross-sectional view illustrating a configuration of a tilt sensor according to a second embodiment of the present invention.

FIG. 5 is a sectional view taken along line AA of the tilt sensor shown in FIG. 4;

FIG. 6 is a cross-sectional view illustrating a configuration of a tilt sensor according to a third embodiment of the present invention.

FIG. 7 is a block diagram illustrating a circuit configuration according to a third embodiment;

FIG. 8 is a perspective view showing the appearance of a tilt sensor according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a configuration of a conventional tilt sensor.

[Explanation of symbols]

 10, 40, 60, 70 Inclination sensor 12, 41, 61, 71 Container 13 Liquid 14 Gas 15 LED 17, 17A, 17B Phototransistor 19 Light guide plate 44 Cover 44A Moderation part 45, 72 Sensor part 46 Spring member 47 Slider 71A- 71D piece

Claims (6)

[Claims] 1. A container formed of a material that transmits light, in which a liquid and a gas are sealed, a light projecting device for projecting light to a predetermined position of the container, and a light projecting device of the light projecting device. And a light receiving means for receiving light reflected from a predetermined position of the container by the tilt sensor. 2. The tilt sensor according to claim 1, wherein the container is formed in a dome shape. 3. A container formed of a material that transmits light and having a cylindrical shape and a curved shape as a whole, in which a liquid and a gas are sealed, and provided at the same distance from the center of the container on both the left and right sides. And a sensor unit having a light projecting unit for projecting light to the container and a light receiving unit for receiving light reflected from the container by the light projecting of the light projecting unit. Sensor. 4. The tilt sensor according to claim 3, further comprising: a position changing unit that is provided for each of the two sensor units and changes a position of the sensor unit in a length direction of the container. An inclination sensor characterized by the above-mentioned. 5. A container formed of a material that transmits light and having a cylindrical shape and a curved shape as a whole, a reflecting member provided on an inner wall surface, and a liquid and a gas sealed inside the container. A first light receiving unit provided in the container so as to be positioned on the gas in the container when in a horizontal state, and the container 61 is tilted to one of left and right at a predetermined angle. A second light receiving means provided in the container so as to be located on the gas in the container together with the first light receiving means;
And a light projecting means provided at an end of the container on the side of the second light receiving means and projecting light into the container. 6. A container which is formed in a cross shape and has a curved shape as a whole by a material which transmits light, in which a liquid and a gas are sealed, and which is provided on each of four sides of the container. A tilt sensor, comprising: a light projecting unit for projecting light, and a sensor unit having a light receiving unit for receiving light reflected from the container by the light projecting by the light projecting unit.