JP4971049B2 - Tilt sensor - Google Patents

Description

  The present invention relates to a tilt sensor that detects a tilt of a housing member by detecting a tilt of a pendulum member that is pivotally supported in the housing member.

  Conventionally, as a tilt sensor that detects the tilt of a moving body such as a vehicle, an MR element (magnetoresistance element) that magnetically detects the position of a pendulum or a sphere that moves by the weather slope, Light-emitting diodes and photosensors that detect optically are used. However, these MR elements and photosensors are expensive and difficult to downsize. Therefore, the position of the magnet installed on the pendulum that moves by tilting, the Hall IC (Hall element that converts the magnetism into voltage using the Hall effect that the magnetic field affects the semiconductor, voltage amplifier, and comparator are built-in, An inclination sensor having an inexpensive and simple structure has been proposed by detecting with an IC that changes the output terminal voltage by comparing the magnetic quantity with a reference value (see, for example, Patent Document 1 and Patent Document 2).

  The present applicant has proposed a tilt sensor using a pendulum and a ball (Japanese Patent Application No. 2006-34887). This inclination sensor is a sensor that enables an inclination determination angle to be arbitrarily set while preventing erroneous determination. FIG. 8 is a diagram showing an example of this type of tilt sensor, where (a) is a front view and (b) is a side view. An inclination sensor 71 shown in FIG. 8 is configured by housing a pendulum 73 and a ball 74 in a casing 72, and a damping liquid 75 is sealed in a space in the casing 72. Due to the inclination of the casing 72, when the ball 74 rolls on the rolling surface 76 formed of an inclined surface formed in the casing 72, the pendulum 73 swings along with the rolling. The Hall IC 78 provided as a detection means in the casing 72 detects the strength of the magnetic field generated by the magnet 77 provided in the pendulum 73, so that the pendulum 3 is inclined with respect to the casing 2 at a predetermined angle or more. Detect that The pendulum 73 is rotatable about the casing 72 by a swing shaft 79, and includes a main body 80 integral with the swing shaft 79, and a pair of arms 81, 81 extending from the main body 80 in the front-rear direction of the swing direction. ing. The ball 74 is accommodated in the housing 72 so as to be fitted into a pendulum groove 82 formed between the pair of arms 81 and 81.

  However, in this type of tilt sensor 71, bubbles may accumulate in the pendulum groove 82 during manufacture and during handling after completion of assembly. In this state, when the casing is tilted to the vicinity of the set detection angle (the angle at which the ball 74 rolls off the set inclined surfaces 76 and 76), as shown in FIG. 9, the buoyancy of the bubble 85 (the volume of the bubble) Becomes a resistance force against the rolling force of the pendulum 73, and the detection angle (the inclination angle of the housing 72 at which the output of the Hall IC 78 is switched) becomes a factor.

  In the conventional inclination sensor, as shown in FIG. 9, since the bubbles 85 do not escape once entering the pendulum groove 82, buoyancy (direction of buoyancy: upward direction in FIG. 9) is applied to the pendulum 73, and the inclination is inclined. Resistant to rotational force in the direction.

The above-mentioned “rolling force of the pendulum” refers to a rotational force that tries to push the ball 74 to the left or right set inclined surface 76 or 76 by the weight of the pendulum 73 when the casing 72 is in an inclined state. 74 is a force already transmitted to the ball 74 before starting to roll on the set inclined surfaces 76 and 76. Therefore, since the “rolling force of the pendulum” is one element of the trigger for the ball 74 to start rolling, the inclination angle (setting detection angle) of the housing 72 itself at which the ball 74 starts to move changes when this force changes. This is not a desirable phenomenon in terms of angle accuracy.
JP 2001-324324 A (refer to claims) JP 2000-149736 A (refer to the claims)

  Thus, in an inclination sensor that detects the inclination of the housing member by detecting the inclination of the pendulum member that is pivotally supported in the housing member, the problem to be solved in that the bubbles accumulated in the pendulum groove are efficiently removed. There is.

  The object of the present invention is to make it possible to effectively eliminate bubbles even if they accumulate in the pendulum groove. It is providing the inclination sensor which can suppress this and can improve the precision of a detection angle.

  In order to solve the above-described problems, a tilt sensor according to the present invention includes a housing in which liquid is sealed, a pendulum body housed in the housing and pivotally supported by the housing, and a pair extending from the pendulum body. A pendulum having an arm and a pendulum groove formed between the pair of arms of the pendulum. The pendulum is housed in the housing and can roll on a rolling surface formed in the housing. And a passage through which the pendulum main body of the pendulum passes upward from the pendulum groove portion, the detection unit detecting a tilt of the housing in accordance with the swing amount of the pendulum caused by rolling of the ball. It consists of being formed.

  According to this inclination sensor, when the housing is inclined relative to the pendulum, the ball rolls on the rolling surface formed on the housing, and the ball is formed between the pair of arms. The pendulum fitted in the groove swings according to the rolling of the ball because the pendulum body is pivotally supported by the housing. The detecting means can detect the inclination of the housing according to the swing amount of the pendulum caused by the rolling of the ball. Bubbles accumulated in the pendulum groove during manufacture and after assembly is completed above the liquid through a passage formed in the pendulum main body in a manner that escapes upward from the pendulum groove due to the buoyancy of the bubble itself. Since it moves, the buoyancy of the bubbles does not act on the ball as a resistance against the rolling force of the pendulum, and variation in detection angle can be prevented.

  In this inclination sensor, the passage may be formed as a single passage formed at one central position in the swing direction of the pendulum that wraps around the swing axis of the pendulum body. Further, the passage can be formed by dividing the swing axis of the pendulum body into two places sandwiching the swing direction of the pendulum in the front-rear direction.

  In this inclination sensor, the passage may be formed to be inclined in the axial direction of the swing axis. The passage formed so as to be inclined in the axial direction of the swing axis opens more than the actual passage width with respect to the pendulum groove, so that bubbles easily enter the passage. In addition, when the housing is attached and there is an angle in the axis direction of the swing axis, it is possible to adjust the direction in which the bubbles are about to rise in the direction opposite to the direction of gravity.

  Further, in this inclination sensor, the passage can be an enlarged passage whose passage sectional area increases upward from the pendulum groove. By setting the passage as an enlarged passage, bubbles that have entered the passage from the pendulum groove portion side have less resistance in the passage and can easily escape upward. The passage may expand continuously or gradually. Furthermore, the wall surface facing the front and rear in the swing direction of the pendulum among the wall surfaces of the enlarged passage can be formed smoothly. When the wall surface is curved, the resistance to bubbles can be reduced as compared with the case where the wall surface is flat.

  Further, in this tilt sensor, the pendulum includes a pendulum side portion extending from the pendulum main body and connecting the arms laterally and a magnet embedded in the pendulum side portion, and the detecting means is the pendulum. It can be set as the Hall IC which is provided in a case and detects the intensity of the magnetic field of the magnet. Since the pendulum having such a structure can be shared by the arm portion that sandwiches the ball and the portion having the magnet along the direction of the swing axis, the housing can be downsized.

  Since the tilt sensor according to the present invention is configured as described above, the tilt sensor in the casing is independent of the tilt angle in the front-rear direction, that is, the swing axis direction, and the clearance dimension between the pendulum and the casing. Even if the bubbles accumulate in the pendulum groove, the bubbles can escape from the passage to the upper side of the pendulum by their buoyancy. Thereby, since the pendulum is not affected by the buoyancy of the bubbles, it is possible to prevent the detection angle variation range from expanding due to the bubbles. Furthermore, by reducing the clearance dimension between the pendulum and the housing, the entire housing can be reduced in size.

  When the inside of the housing is subjected to vibration or lateral G (lateral acceleration), such as when the vehicle to which the tilt sensor is attached is in a running state, the ball will not drop out of the pendulum groove and air bubbles will escape sufficiently The passage size can be set large.

  Hereinafter, embodiments of the tilt sensor according to the present invention will be described with reference to the accompanying drawings. 1A and 1B are views showing a first embodiment of a tilt sensor according to the present invention, in which FIG. 1A is a front view and FIG. 1B is a side view.

  In the tilt sensor 1 shown in FIGS. 1A and 1B, the pendulum 3 and the ball 4 are accommodated in the housing 2, and the damping liquid 5 is sealed in the space in the housing 2. Due to the inclination of the housing 2, when the ball 4 rolls on the rolling surface 6 formed of an inclined surface formed in the housing 2, the pendulum 3 swings along with the rolling. The pendulum 3 is provided with a magnet 7, and the housing 2 is provided with a Hall IC 8 as detection means. The Hall IC 8 detects that the pendulum 3 is inclined at a predetermined angle or more with respect to the housing 2 by detecting the strength of the magnetic field generated by the magnet 7 by the interaction with the magnet 7. The pendulum 3 is rotatable about the housing 2 by a swing shaft 9 and includes a main body 10 integrated with the swing shaft 9 and a pair of arms 11 and 11 extending from the main body 10 in the front-rear direction of the swing direction. ing. The ball 4 is housed in the housing 2 in a state of being fitted into a pendulum groove portion 12 formed between the pair of arms 11 and 11. The structure of the pendulum 3 and its detection operation itself are the same as those of a conventional tilt sensor.

  In the pendulum 3 of the tilt sensor 1, passages 13 and 13 are formed in the region of the pendulum main body 10 so as to escape from the pendulum groove 12 to the top at the top in order to remove bubbles, as indicated by hatching. As shown in FIG. 1A, which is a front view, the passages 13 and 13 are formed at two locations that sandwich the axis 9a of the swing shaft 9 of the pendulum main body 10 in the front and rear directions in the swing direction of the pendulum. Specifically, the passages 13 and 13 are formed in the pendulum 3 body 10 in a neutral state so as to penetrate the axis 9 a of the swing shaft 9 in the front and rear directions in the swing direction of the pendulum 3. The axes 13a and 13a are set obliquely at the same angle θ1 with respect to the vertical center line of the pendulum 3. Further, as shown in FIG. 1B which is a side view, in the direction of the axis 9 a of the swing shaft 9, it is not formed in the full width region but has a width A substantially corresponding to the diameter of the ball 4. It is formed only in the region. The passages 13 and 13 are open in one direction of the axis 9 a of the swing shaft 9, but the other side extends from the pendulum body 9 and the pendulum side portion that connects the arms 11 and 11 laterally. The Hall IC 8 provided in the housing 2 can detect the strength of the magnetic field by the magnet 7 embedded in the pendulum side portion 14.

  Air may accumulate in the pendulum groove 12 during manufacture of the tilt sensor 1 and during handling after assembly. The accumulated air becomes bubbles 15 and tries to rise in the damping liquid 5 by the buoyancy of the bubbles themselves. The bubbles 15 are resistant to the rolling force of the pendulum 3 while staying in the pendulum groove 12, but in this embodiment, the bubbles 15 exit from the pendulum 3 through the passages 13 and 13. Therefore, the buoyancy of the bubbles 15 does not act on the ball, and the detection angle does not vary. As shown in FIG. 1B, the width A of the passage 13 is such that the ball 4 does not fall off the pendulum 3 regardless of the clearance B between the pendulum 3 and the housing 2. And it sets so that the bubble 15 in the pendulum groove part 12 may escape upwards. By reducing the clearance dimension B, the entire housing 2 can be reduced in size. Even if the clearance dimension B is extremely small, the dimension A which is the depth of the passage 13 can be taken large, and the bubbles 15 can escape upward.

Table 1 shows values obtained by actually measuring angle detection using a sample in which bubbles are intentionally put in the pendulum groove and a sample without bubbles. The influence of bubbles is clear from the difference in the amount of deviation of the measured values with respect to the detection angles in the table.

  FIG. 2 is a diagram illustrating a state in which the tilt sensor 1 illustrated in FIG. 1 is tilted. In the conventional tilt sensor, as shown in FIG. 9, since the bubbles 85 once entering the pendulum groove portion 82 do not escape, the buoyancy of the bubbles applied to the pendulum 73 becomes a resistance to the rotational force in the tilt direction. . On the other hand, in the inclination sensor of the present invention, the bubbles 15 are pulled out above the pendulum 3 before reaching the set detection angle, thereby preventing variation in the detection angle.

  FIG. 3 is a front view (a) and a side view (b) showing a second embodiment of the tilt sensor according to the present invention. In the second embodiment shown in FIG. 3 and each embodiment shown thereafter, those having the same functions as the components and parts of the first embodiment shown in FIG. The description of is omitted. The second embodiment shown in FIG. 3 has a structure in which the bubbles 15 accumulated in the pendulum groove 12 are removed when the inclination angle of the inclination sensor 21 is zero. That is, the pendulum 23 is formed with a passage 25 through the pendulum body 24 of the pendulum 23 in the vertical direction (axis 25a) in a non-tilt state where the tilt angle is zero. Bubbles accumulated in the pendulum groove 12 escape through the passage 25 to the outside outside the pendulum 23. The passage 25 is formed so as to intersect with the swing shaft 9 of the pendulum 23, but the swing shaft 9 does not extend in the passage 25 on both sides of the pendulum body 24 so as not to reduce the cross-sectional area of the passage. It can also be provided only.

  FIG. 4 is a front view (a) and a side view (b) showing a third embodiment of the tilt sensor according to the present invention. The tilt sensor 31 shown as the third embodiment also has a structure in which the bubbles 15 accumulated in the pendulum groove 12 are removed when the tilt angle is zero, and the pendulum body 34 of the pendulum 33 faces upward in a non-tilt state where the tilt angle is zero. A passage 35 is formed. In the third embodiment, unlike the first embodiment shown in FIG. 1, the axis 35a of the passage is inclined in the front-rear direction (perpendicular to the tilt direction, that is, the direction parallel to the swing axis direction of the pendulum 33). Yes. By forming the passage 35 obliquely in the front-rear direction, the width C of the passage inlet portion 35b that opens to the pendulum groove portion 12 can be secured larger than the actual passage width D. Since the bubbles 15 always try to escape in the direction opposite to the direction of gravity, according to the inclination sensor 31 of the third embodiment type, when there is an angle in the front-rear direction when attached to an object (such as a motorcycle), It is possible to select and apply an inclination sensor with the removal direction adjusted. In order not to reduce the cross-sectional area of the passage, it can be provided only on both sides of the pendulum body 34 so that the swing shaft 9 does not extend in the passage 35.

  FIG. 5 is a front view (a) and a side view (b) showing a fourth embodiment of the tilt sensor according to the present invention. The tilt sensor 41 according to the fourth embodiment has a structure that eliminates as much physical factors as possible to prevent the bubbles 15 from coming out of the pendulum 43. That is, the pendulum main body 44 is formed in an extended portion of the pendulum side portion 14 that is fitted to the swing shaft 9 and swings and supports the pendulum 43, and is left in a portion offset in the front-rear direction from the position of the ball 4. ing. Correspondingly, the upper part of the pendulum groove 12 (region E shown in (a)) is removed to form an open passage 45 that is completely open upward except that the swing shaft 9 is present. The upper ends of the arms 11 and 11 are also formed on slopes 11 a and 11 a that open obliquely with respect to the pendulum groove 12, and are opened with a width exceeding the width dimension F between the arms 11 and 11. The bubbles 15 entering the pendulum groove 12 can escape above the pendulum 43 without being blocked. Although the swing shaft 9 is in the open passage 45, the ratio of the passage cross-sectional area is small and the surface is rounded, so that the bubbles 15 are not trapped by the swing shaft 9 in the middle.

  FIG. 6 is a front view showing a fifth embodiment of the tilt sensor according to the present invention. In the inclination sensor 51 as the fifth embodiment, the passage 55 for extracting the bubbles 15 upward is formed as an enlarged passage whose passage sectional area increases upward from the pendulum groove portion 12. Moreover, the wall surfaces 56a and 56b (shown by thick line portions) facing the swinging (tilting) direction of the pendulum 53 among the wall surfaces of the enlarged passage are curved in a direction that promotes upward escape of the bubbles 15. It has a smooth curved surface. The wall surfaces 56a and 56b are more resistant to bubbles being removed from the pendulum groove portion 12 as compared with the case where the wall surfaces 56a and 56b are formed in a planar shape (linear shape in cross section) as shown in FIG. It has a structure with reduced force. In the illustrated example, the wall surfaces 56a and 56b are both curved surfaces, but in the case of a combination in which one wall surface is a flat surface and the other wall surface is a curved surface, or both wall surfaces are combined surfaces of straight lines and curves. Is also possible.

  FIG. 7 is a front view (a) and a GG sectional view (b) showing a sixth embodiment of the tilt sensor according to the present invention. In the tilt sensor 61 according to the sixth embodiment, the length direction H of the passage 65 formed in the pendulum body 64 becomes a direction immediately above the tilt angle of the housing 2 reaching the set detection angle, and the bubbles 15 are pendulum. This is a structure that extends upward from 63. By having the passage 65 obliquely, the width of the passage inlet portion 65b (thick line in the drawing) can be ensured longer than the actual passage width. Further, by providing the tapered surfaces 66a and 66b when viewed in the section GG, the strength of the pendulum 63 (strength against repeated load due to contact with the ball 4 or the like) can be increased.

  As described above, the embodiments of the tilt sensor according to the present invention have been exemplified as those having a substitute passage structure. However, in the implementation of the present invention, these embodiments are of course combined with these features. These are all included as examples of the present invention.

It is a figure which shows 1st Example of the inclination sensor by this invention. It is a figure which shows an example of the bubble missing state in the inclination sensor shown in FIG. It is a figure which shows 2nd Example of the inclination sensor by this invention. It is a figure which shows 3rd Example of the inclination sensor by this invention. It is a figure which shows 4th Example of the inclination sensor by this invention. It is a figure which shows 5th Example of the inclination sensor by this invention. It is a figure which shows 6th Example of the inclination sensor by this invention. It is a figure which shows an example of the conventional inclination sensor. It is a figure which shows an example of the accumulation state of the bubble in the conventional inclination sensor.

Explanation of symbols

1, 21, 31, 41, 51, 61 Tilt sensor 2 Housing 3, 23, 33, 43, 53, 63 Pendulum 4 Ball 5 Damping fluid 6 Rolling surface 7 Magnet 8 Detection means (Hall IC)
9 Oscillating shaft 9a Axis 10, 24, 34, 44, 54, 64 Pendulum body 11, 11 Arm 12 Pendulum groove 13, 25, 35, 45, 55, 65 Passage 13a, 13a Axis 14 Pendulum side 15 Bubble 25a, 35a Axis 35b, 65b Passage inlet 56a, 56b Wall surface 66a, 66b Tapered surface A width B Clearance dimension C width D Actual passage width E Area F Width dimension

Claims (7)

A housing in which liquid is enclosed, a pendulum having a pendulum body housed in the housing and pivotally supported by the housing and a pair of arms extending from the pendulum body, and between the pair of arms of the pendulum A ball that is accommodated in the housing in a state of being fitted into a pendulum groove formed on the housing and that can roll on a rolling surface formed on the housing, and the ball that is caused by the rolling of the ball. A detecting means for detecting the inclination of the housing according to the swing amount of the pendulum;
A tilt sensor comprising a passage penetrating upward from the pendulum groove in the pendulum body of the pendulum.   The inclination sensor according to claim 1, wherein the passage is a single passage formed at a central position in the swing direction of the pendulum that wraps around the swing axis of the pendulum body.   2. The inclination sensor according to claim 1, wherein the passage is formed at two positions sandwiching a swing axis of the pendulum main body in front and rear of the swing direction of the pendulum.   The inclination sensor according to claim 1, wherein the passage is formed to be inclined in an axial direction of the swing axis.   The inclination sensor according to claim 1, wherein the passage is an enlarged passage whose passage cross-sectional area increases upward from the pendulum groove.   The inclination sensor according to claim 5, wherein a wall surface facing the front and rear of the swinging direction of the pendulum among the wall surfaces of the enlarged passage is formed smoothly.   The pendulum includes a pendulum side portion extending from the pendulum main body and connecting the both arms laterally, and a magnet embedded in the pendulum side portion, and the detection means is provided in the housing and is provided with the magnet. 2. The tilt sensor according to claim 1, wherein the tilt sensor is a Hall IC that detects the strength of a magnetic field.

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