Distance sensor module

Abstract

To provide a distance sensor module that can accurately measure the distance to a measurement target.SOLUTION: A distance sensor module A includes a distance sensor S and a housing H. The distance sensor S has a transmitting / receiving unit 12 connected to a sensor body 10, and can measure, in the sensor body 10, the distance to a measurement target by receiving, by the transmitting / receiving unit 12, a detection signal that is transmitted from the transmitting / receiving unit 12 and reflected by the measurement target. The housing H has a sensor housing portion Hs that houses the distance sensor S, and an attachment portion 22 that attaches the sensor housing portion Hs to an external attachment target. The sensor housing portion Hs maintains a posture in which a detection direction of the transmitting / receiving unit 12 faces a vertically downward direction due to the action of gravity in the state in which the attachment portion 22 is attached to the attachment target.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a distance sensor module.

Background Art

[0002] As a distance sensor module, Patent Document 1 describes a water surface sensor using ultrasonic waves so as to detect the water surface of a water channel without contact.

[0003] As a distance sensor module, Patent Document 2 describes a water level sensor connected to a wireless communication control unit on the back surface (lower surface) of a manhole cover body via a connection cable.

[0004] As a distance sensor module, Patent Document 3 describes a water level measuring device including a light source composed of an LED for emitting a light beam onto the water surface, and a non-contact type light position detector composed of a PSD capable of detecting a light receiving position by receiving the light beam reflected from the water surface.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] Here, considering the installation position of a distance sensor module for the water surface of water flowing in a conduit, it is convenient to provide it on the lower surface of a manhole cover as shown in Patent Document 2.

[0007] Distance sensor modules for measuring water levels in conduits come in contact and non-contact types, depending on the measurement method. Contact types include float type, guide rope type, pressure type (as shown in Patent Document 2), capacitance type, differential pressure type, etc., while non-contact types include radio wave type, ultrasonic type (as shown in Patent Document 1), optical type (as shown in Patent Document 3), etc.

[0008] While contact-type sensors are relatively inexpensive, they are susceptible to deformation and damage from contact with foreign objects in the water, and foreign objects can adhere to them, preventing accurate measurements. Furthermore, these contact-type sensors require the sensing unit to be installed in the water of the pipe during installation and maintenance, which can be time-consuming, sometimes requiring the water to be drained and zero-point adjustments made after each maintenance, thus shortening the maintenance cycle.

[0009] In contrast, non-contact sensors do not cause deformation or damage like contact sensors do, and maintenance is easy. On the other hand, non-contact distance sensor modules require adjustment to maintain a predetermined angle with respect to the water surface. For example, if a detection signal needs to be sent in a direction that is 90 degrees to the water surface (vertical direction), the orientation of the distance sensor module must be set with high precision.

[0010] To address these challenges, as described in Patent Documents 1 and 3, a distance sensor module is configured to measure the distance to the water surface by using detection signals such as ultrasound or light rays and detecting the detection signals reflected from the water surface. However, if the angle at which the detection signal is sent to the water surface is set to an angle other than 90 degrees, calculations are required to determine the distance based on the set angle.

[0011] Thus, in distance sensor modules that detect the water surface using a detection signal, setting the direction of the detection signal transmission vertically downward is important for facilitating measurement and maintaining high measurement performance. It should be noted that Patent Documents 1-3 do not describe how adjusting the orientation of the distance sensor module can improve measurement accuracy.

[0012] Manhole covers are sometimes opened and closed during maintenance work on the pipelines. For example, even if the cover is closed after being opened, if it is not properly positioned, such as being tilted, the position of the distance sensor module attached to the underside of the cover may also be tilted, raising concerns that the measured water level may become inaccurate.

[0013] Such concerns are not limited to water when measuring; they can also arise with other fluids or even solids.

[0014] For these reasons, there is a need for a distance sensor module that can accurately measure the distance to the target object even when set up in an improper position. [Means for solving the problem]

[0015] The characteristic configuration of the distance sensor module according to the present invention comprises a distance sensor and a housing, wherein the distance sensor has a sensor body and a transmitting / receiving unit connected to the sensor body, and is configured to be a non-contact type in which the distance to the object to be measured is measured by the sensor body when the detection signal transmitted from the transmitting / receiving unit is reflected by the object to be measured and then received by the transmitting / receiving unit, and the housing has a sensor housing unit for housing the distance sensor and a mounting unit for attaching the sensor housing unit to an external mounting object, wherein the sensor housing unit is maintained in a position in which the detection direction of the transmitting / receiving unit is directed vertically downward due to the action of gravity when the mounting unit is attached to the mounting object.

[0016] With this feature configuration, when the housing is attached to the mounting object by the mounting part, gravity maintains the detection direction of the transmitting and receiving unit in a vertically downward orientation. Therefore, even if the orientation of the mounting object changes, the orientation of the distance sensor can be maintained in the optimal orientation relative to the object being measured. Therefore, a distance sensor module was constructed that can accurately measure the distance to the object being measured even when it is set up in an improper position.

[0017] As a configuration added to the above configuration, the transmission / reception unit is arranged to face the measurement target, and the center of gravity of the distance sensor may be located on the central axis of the transmission / reception unit.

[0018] According to this, by setting the posture of the distance sensor so that the center of gravity is located on the central axis of the transmission / reception unit due to the action of gravity, it becomes possible to send out the detection signal of the distance sensor vertically downward.

[0019] As a configuration added to the above configuration, the sensor housing portion may house the distance sensor so that the posture can change within a preset range.

[0020] According to this, as long as the posture of the distance sensor changes within a preset range, the distance sensor does not contact the inner surface of the housing, and a free posture is allowed.

[0021] As a configuration added to the above configuration, when the distance sensor changes its posture within a preset range, the protruding amount downward from the lower end position of the sensor housing portion is set so that the distance sensor does not protrude from the lower end of the sensor housing portion in a side view.

[0022] According to this, even when the inclination of the distance sensor reaches the maximum, in a side view, a part of the distance sensor does not protrude downward from the lower end of the vertical outer wall. For example, when the distance sensor module is provided on the lower surface of the manhole cover and the cover accidentally falls to the ground, the sensor housing portion protects the distance sensor even in a situation where an impact due to the weight of the cover acts, and the distance sensor is not damaged.

[0023] [[ID=​​​​​​​ As a configuration added to the above configuration, a fixing member may be provided that fixes the posture change of the distance sensor housed in the sensor housing portion so as to be impossible.

[0026] According to this, the fixing member makes it impossible for the posture of the distance sensor housed in the sensor housing portion to change. By using such a fixing member, for example, the distance sensor does not strongly contact the inner surface of the housing even in a situation where vibration acts.

[0027] As a configuration added to the above configuration, the distance sensor is housed in the sensor housing portion in a manner that allows a posture change by swinging with respect to the housing, and one of the distance sensor and the housing has a swing fulcrum, and the other of the distance sensor and the housing has a swing receiving portion that supports the swing fulcrum. The one of the swing fulcrum and the center of the swing receiving portion that the distance sensor has may be located vertically above the center of gravity of the distance sensor.

[0028] According to this, when the posture of the housing is in a posture deviated from the proper posture, the distance sensor swings around this swing fulcrum in a state where the swing receiving portion supports the swing fulcrum, so that the distance sensor is positioned vertically above the center of gravity of the distance sensor, and it becomes possible to send out a detection signal vertically downward from the distance sensor.

[0029] As a configuration added to the above configuration, the attachment portion may have the swing fulcrum that tapers upward from the upper end in a posture protruding upward, and the distance sensor may have the swing receiving portion that is a concave surface where the upper end of the swing fulcrum abuts and is open downward.

[0030] According to this, the upper end of the swing fulcrum that tapers upward from the upper end in a posture extending upward abuts against the concave surface that is open downward in the swing receiving portion, so that the distance sensor is suspended with the contact position as a support point, and it becomes possible to direct the direction of sending out the detection signal by the distance sensor vertically downward by this suspension.

[0031] In addition to the above configuration, the distance sensor may have a pivot point that protrudes downward and whose diameter decreases towards the lower end, and the mounting portion may have a pivot receiving portion which is a concave surface that abuts against the lower end of the pivot point and is open upward.

[0032] According to this design, the lower end of the pivot point, which extends downward and becomes smaller in diameter towards the bottom, contacts a concave surface that opens upward in the pivot receiving section. This contact point serves as a support point from which the distance sensor is suspended, and this suspension allows the direction of the detection signal from the distance sensor to be directed vertically downward.

[0033] In addition to the above configuration, a buffer member may be provided, which is positioned to contact the housing and the distance sensor, and which suppresses the transmission of vibrations from the mounting portion to the distance sensor.

[0034] According to this, the damping material absorbs vibrations transmitted from the mounting part of the housing, suppressing vibrations in the distance sensor and enabling highly accurate measurement.

[0035] In addition to the above configuration, the system may further include a buffer member that contacts the housing and the distance sensor and is positioned in a region surrounding the pivot point.

[0036] According to this, regardless of the direction in which the distance sensor's orientation relative to the housing vibrates, the cushioning material absorbs the vibration and also prevents dust from entering the area where the pivot point is located.

[0037] In addition to the above configuration, the distance sensor may be configured as a millimeter-wave radar sensor using millimeter waves as the detection signal, and the portion of the distance sensor covering the transmitting and receiving unit may be made of an insulator.

[0038] According to this, the outer surface of the transmitting and receiving unit can be protected with an insulator, and because the distance sensor is a millimeter-wave radar sensor that uses millimeter waves as a detection signal, it can measure the distance to the object being measured without being affected by the environment, compared to those that use light rays.

[0039] Another characteristic configuration of the distance sensor module according to the present invention is that it comprises a distance sensor and a housing, the distance sensor having a sensor body and a transmitting / receiving unit connected to the sensor body, and is configured to be a non-contact type in which the distance to the object to be measured is measured by the sensor body when a detection signal transmitted from the transmitting / receiving unit is reflected by the object to be measured and then received by the transmitting / receiving unit, the housing having a sensor housing for housing the distance sensor and a mounting part for attaching the sensor housing to an external mounting object, the housing has a support mechanism that supports the distance sensor so as to be able to change its orientation by suspending the end of the distance sensor opposite to the transmitting / receiving unit, and the sensor housing maintains the orientation in which the detection direction of the transmitting / receiving unit is directed vertically downward by the action of gravity when the mounting part is attached to the mounting object.

[0040] With this feature configuration, when the housing is supported via the mounting section, the housing's support mechanism supports the opposite side of the transmitting / receiving section of the distance sensor in a manner that allows for changes in orientation. This makes it possible to maintain the transmitting / receiving section of the distance sensor in a position where it is facing vertically downwards due to the action of gravity. This resulted in a distance sensor module that can accurately measure the distance to the target object even when set up in an improper position. [Brief explanation of the drawing]

[0041] [Figure 1] This is a cross-sectional view showing the arrangement of pipes and manhole covers. [Figure 2] This is a perspective view of the distance sensor module. [Figure 3] This is a disassembled perspective view of the distance sensor module. [Figure 4]This is a longitudinal cross-sectional side view of the distance sensor module. [Figure 5] This is a cross-sectional view of the distance sensor module when the housing is in an inclined position. [Figure 6] This is a cross-sectional plan view of the distance sensor module. [Figure 7] This is a cross-sectional view of a distance sensor module according to another embodiment (a). [Figure 8] This is a cross-sectional view of a distance sensor module according to another embodiment (b). [Modes for carrying out the invention]

[0042] Embodiments of the present invention will be described below with reference to the drawings. [Basic configuration] As shown in Figure 2, the distance sensor module A is configured with a distance sensor S and a housing H that houses the distance sensor S.

[0043] The distance sensor S is configured as a non-contact type that measures the distance to the object to be measured by sending a detection signal (millimeter wave) from the transmitting / receiving surface 12S of the transmitting / receiving unit 12 shown in Figure 4 to the object to be measured, and receiving the detection signal reflected by the object to be measured with the transmitting / receiving surface 12S of the transmitting / receiving unit 12.

[0044] As shown in Figure 1, in this embodiment, the distance sensor module A is mounted on the underside of the manhole cover 3 (an example of an installation target) of the pipe 1, and the water level of the water flowing in the pipe 1 is measured. That is, the distance sensor module A measures the distance to the water surface f by facing the transmitting / receiving unit 12 of the distance sensor S toward the water surface f. Note that this distance sensor module A may be used not only in pipe 1 but also in other configurations to measure the distance to the water surface f of water flowing in waterways, etc.

[0045] A communication unit 4 is provided on the underside of the manhole cover 3, which receives distance information from the distance sensor module A. The communication unit 4 has a battery (not shown) inside and wirelessly transmits the distance information to the water surface f detected by the distance sensor module A to a server or other device that manages the pipe 1.

[0046] Since this distance sensor module A is used in the orientation shown in Figures 2 and 4, the relationship between the vertical and horizontal positions will be explained in relation to this orientation. The vertical direction is the direction indicated by the sign "Z" in Figures 2 and 4.

[0047] The distance sensor module A is supported in such a manner that the distance sensor S (sensor body 10) is suspended from the housing H via a posture maintenance unit V, so as to maintain an orientation that sends a detection signal vertically downward from the transmitting / receiving surface 12S of the transmitting / receiving unit 12 of the distance sensor S. As shown in Figure 4, the posture maintenance unit V is composed of a pivot member 23 (an example of a swinging pivot VA) and a concave surface 15S (an example of a swinging receiving part VS).

[0048] [Specific structure: distance sensor] As shown in Figures 2 to 6, the distance sensor S has a sensor body 10 that is square (rectangle) in plan view (view in the Z direction) and has a cylindrical projection 11 on its lower surface, and an internal transmitting / receiving unit 12. The sensor body 10 and the projection 11 are integrally formed from insulating resin, and the outside of the transmitting / receiving surface 12S of the transmitting / receiving unit 12 is also covered with resin.

[0049] The distance sensor S is not limited to a square shape in plan view; it may also be circular, polygonal, or other shapes. Even if the distance sensor S is not oriented in the forward direction in plan view, it is still possible to form a support shaft 14 protruding horizontally outward from the main body wall 10a, similar to the configuration shown in Figures 3 and 6.

[0050] In addition, while cross-sectional views such as Figure 4 show the transceiver unit 12 inserted into the resin insulator of the distance sensor S, a structure may also be adopted in which the outer wall of the distance sensor S is configured as a hollow case and the transceiver unit 12 is housed inside this case.

[0051] The sensor body 10 contains a sensor control circuit (not shown) that controls the transmitting / receiving unit 12 to acquire distance information and sends the acquired distance information to the communication unit 4.

[0052] The transmitting / receiving unit 12 functions as a millimeter-wave radar that measures the distance to the water surface f by sending out millimeter waves as a detection signal from the protruding end face of the protruding portion 11 and receiving the millimeter waves reflected by the water surface f.

[0053] The sensor body 10 has its center of gravity W approximately in the center when viewed from above, and the transmitting / receiving unit 12 is positioned below the center of gravity W. As shown in Figure 4, the center of gravity W is located on the central axis of the transmitting / receiving unit 12 (overlapping with the center of gravity line WL). With this configuration, the distance sensor module A supports the sensor body 10 by suspending it with an attitude maintenance unit V located higher than the center of gravity W. By the action of gravity, the center of gravity line WL, which passes through the center of gravity W and the transmitting / receiving unit 12, is maintained in a vertical position.

[0054] The sensor body 10 can be configured such that the transmitting / receiving unit 12 is positioned at a location that overlaps with the center of gravity line WL, or at a location that overlaps with the center of gravity W (the same location), and the detection direction of the transmitting / receiving unit 12 can be directed vertically downward. For this reason, a configuration in which the transmitting / receiving unit 12 is positioned above the center of gravity W and overlaps with the center of gravity line WL, or a configuration in which the transmitting / receiving unit 12 is positioned at a location that overlaps with the center of gravity W, may also be adopted.

[0055] As shown in Figures 3, 4, and 6, the sensor body 10 has a flat upper end wall 13 formed on the side opposite to the protruding portion 11, and a main body wall 10a is formed that rises upward so as to surround this upper end wall 13. The main body wall 10a has wall portions corresponding to each side of the rectangle of the sensor body 10, and a support shaft 14 is provided projecting horizontally outward from the wall portion corresponding to each side.

[0056] As mentioned above, considering the case where the plan view shape of the distance sensor S is circular or polygonal, if the plan view shape of the distance sensor S is circular, the support shaft 14 will protrude horizontally outward from the circumference of the main body wall portion 10a which is circular in plan view. If the plan view shape of the distance sensor S is polygonal, the support shaft 14 will protrude horizontally outward from each side of the main body wall portion 10a which is polygonal in plan view. Furthermore, even if the plan view shape of the distance sensor S is not circular or polygonal, the support shaft 14 will protrude outward from the outer surface of the main body wall portion 10a which is formed according to these shapes.

[0057] The support shafts 14 have a circular cross-sectional shape, and of these four support shafts 14, two opposing support shafts 14 are arranged on the coaxial axis. In the figure, one of the two orthogonal axes is referred to as the X direction and is denoted by the sign "X," and the other axis is referred to as the Y direction and is denoted by the sign "Y." Furthermore, the direction perpendicular to the X and Y directions is referred to as the up and down direction Z and is denoted by the sign "Z" (see also Figure 2).

[0058] As shown in Figure 6, in a plan view, the axis in the X direction and the axis in the Y direction are positioned such that they intersect at the centroid line WL.

[0059] The distance sensor S is equipped with a support plate 15 located at a position spaced above the upper end wall 13 of the sensor body 10. The support plate 15 has a plate portion 15a that is oriented parallel to the upper end wall 13, arm portions 15b that extend outward from four locations on the outer edge of the plate portion 15a, and leg portions 15c that protrude downward along the vertical direction Z from the extended ends of the four arm portions 15b.

[0060] The four legs 15c are connected to the distance sensor S by inserting screws 16 through the holes that open upward and screwing these screws 16 into the sensor body 10. As shown in Figure 4, the support plate 15 is positioned above the sub-wall 20a of the housing H. To enable this positioning, as shown in Figures 3 and 4, the legs 15c are inserted through the through holes 20b of the sub-wall 20a and connected to the distance sensor S which is positioned below the sub-wall 20a.

[0061] As shown in Figure 4, a concave surface 15S (oscillating support VS) that opens downwards is formed on the lower surface of the plate portion 15a. The concave surface 15S has a hemispherical inner surface, and its deepest part (the part furthest from the subwall portion 20a in the vertical direction Z) intersects with the center of gravity line WL.

[0062] [Specific structure: enclosure] The housing H is integrally formed from resin, comprising a square (rectangular) top wall 20 in plan view, vertical outer walls 21 extending downward from the four outer edges of the top wall 20, and mounting portions 22 extending outward in a flange-like manner from the outer circumference of the top wall 20.

[0063] As shown in Figures 3 and 6, the vertical outer wall 21 is formed by joining four vertical wall bodies 21a at the corners and is shaped like a cylindrical tube that opens downwards. A sensor housing Hs is formed inside these four vertical wall bodies 21a, and the sensor body 10 is housed in this sensor housing Hs so that its posture can change within a preset range.

[0064] In a plan view, a recess is formed in the central part of the upper wall 20, and a flat sub-wall portion 20a is formed at the bottom of the recess. In a plan view, a pivot member 23 (oscillating pivot VA) is integrally formed at the central position of the sub-wall portion 20a, protruding upward and decreasing in diameter towards the upper end. Four through holes 20b are formed around the pivot member 23 in the sub-wall portion 20a. The pivot member 23 is formed in the shape of a rotating body with a central axis in the vertical orientation, tapering towards the end.

[0065] A vertically oriented slit 21b is formed at the center of each of the four vertical wall bodies 21a in the width direction. When the distance sensor module A is assembled, the four support shafts 14 of the sensor body 10 are inserted through the four slits 21b. In this distance sensor module A, the amount of downward protrusion of the lower end position of the vertical outer wall 21 is set so that even when the tilt of the distance sensor S reaches its maximum, a part of the distance sensor S does not protrude downward from the lower end of the vertical outer wall 21 (the lower end of the sensor housing Hs) in a side view (a view in a direction perpendicular to the vertical direction Z). This ensures that the vertical outer wall 21 protects the distance sensor S even in situations where a large impact is applied due to the weight of the manhole cover 3, such as when the manhole cover 3 equipped with the distance sensor module A is accidentally dropped to the ground.

[0066] [Specific structure: Posture maintenance part] As shown in Figure 4, the attitude maintenance unit V has a pivot member 23 (oscillating pivot VA) formed on the side of the housing H and a concave surface 15S (oscillating receiving part VS) formed on the side of the distance sensor S and on the lower surface of the support plate 15.

[0067] This posture maintenance unit V supports the distance sensor S in a way that suspends it from the housing H in a stable position, by having the upper end of the pivot member 23 contact the concave surface 15S of the support plate 15 at its pivot center. In this way, when the position where the upper end of the pivot member 23 and the concave surface 15S of the support plate 15 contact each other is defined as the support point P, the distance sensor S can swing relative to the housing H with this support point P as the center of rotation. In the horizontal position shown in Figure 4, the support point P is in contact with the deepest part of the concave surface 15S of the support plate 15 and is on the center of gravity line WL.

[0068] As shown in Figure 5, if the housing H deviates from the horizontal position shown in Figure 4, the position of the support point P moves along the concave surface 15S, and the position of the pivot center of the pivot member 23 that contacts this concave surface 15S also changes. However, even in this case, the center of gravity line WL is maintained in a vertical position where it passes through the pivot center and the center of gravity W, and the distance sensor S is maintained in a horizontal position.

[0069] In this way, the attitude maintenance unit V enables the attitude of the distance sensor S relative to the housing H around the support point P, and at the same time stabilizes the center of gravity line WL of the distance sensor S in a vertically oriented position due to gravity acting on the distance sensor S, and as a result directs the detection direction by the transmitting and receiving unit 12 vertically downward.

[0070] [Specific structure: regulatory department, etc.] As shown in Figures 2, 3, and 6, the distance sensor module A includes a restricting section R that determines the limit of the change in the orientation of the distance sensor S relative to the housing H. The restricting section R has restricting arms 24 on one of the outer surfaces of a pair of vertical walls 21a that are orthogonal to the X direction, and on one of the outer surfaces of a pair of vertical walls 21a that are orthogonal to the Y direction.

[0071] The regulating arm 24 is supported so as to be able to swing freely around the pivot shaft 25, by inserting a pivot shaft 25 made of screws through a base end hole 24a at its base end and fixing this pivot shaft 25 to the vertical wall 21a. Furthermore, the regulating arm 24 has a limit to its swing by inserting a regulating shaft 26 made of screws through a curved elongated hole 24b in the middle section and fixing this regulating shaft 26 to the vertical wall 21a. In addition, the regulating arm 24 has a support shaft 14 inserted through an interlocking hole 24c located close to the elongated hole 24b, and swings around the pivot shaft 25 as the support shaft 14 is displaced vertically.

[0072] In this embodiment, the regulating section R does not function solely with the regulating arm 24 shown in Figures 2, 3, and 6, but also functions with the elongated hole 24b, the regulating shaft 26, etc. Furthermore, the regulating section R may be composed of a member that determines the oscillation limit by contacting the outer surface of the distance sensor S, or a member that determines the oscillation limit of the distance sensor S by contacting the support shaft 14.

[0073] By using the restricting shaft 26 to fix the oscillation of the restricting arm 24, the restricting shaft 26 can be used as a fixing member. By configuring the fixing member in this way, the oscillation of the restricting arm 24 is made impossible, and the attitude change of the distance sensor S is made impossible. Alternatively, a pair of screws or a pair of pins inserted through the elongated hole 24b can be used as the fixing member, or the fixing member may be configured with a member that determines the oscillation limit by contacting the outer surface of the distance sensor S.

[0074] When the distance sensor S is in a horizontal position relative to the housing H, the pair of support shafts 14 are in the reference position shown in Figure 2, and the two regulating arms 24 are in a horizontal position. However, if the position of the distance sensor S relative to the housing H changes to a state where it forms an inclination angle with respect to the horizontal position, the support shaft 14 inserted through the interlocking hole 24c is displaced upward or downward from the reference position, causing the regulating arm 24 to swing around the pivot support shaft 25 inserted through the base end hole 24a.

[0075] In this configuration, the regulating arm 24 swings around the pivot shaft 25 in accordance with the swing of the distance sensor S relative to the housing H, and the regulating shaft 26 comes into contact with the longitudinal end of the elongated hole portion 24b, preventing further swinging and thus determining the limit of the swinging posture of the distance sensor S.

[0076] As shown in Figures 3 and 4, the distance sensor module A is equipped with a ring-shaped cushioning member 17 located outside the outer circumference of the pivot member 23, sandwiched between the upper surface of the sub-wall portion 20a and the lower surface of the support plate 15. The cushioning member 17 is made of rubber, a flexible resin, or the like.

[0077] Because the distance sensor module A is equipped with a cushioning member 17, if vibrations or shocks are transmitted from the outside, for example, the cushioning member 17 can mitigate the vibrations and shocks acting on the distance sensor S. In addition, the cushioning member 17 converges the vibrations of the distance sensor S, shortening the time it takes for the distance sensor S to come to rest in a vertical orientation, and suppressing inaccurate sensing due to vibrations. Furthermore, the cushioning member 17 prevents dust from entering the space between the tapered portion of the pivot member 23 and the concave surface 15S of the support plate 15.

[0078] [Effects of the Embodiment] The distance sensor module A is connected and fixed to the underside of the manhole cover 3 of the manhole 2 by screws or the like at the mounting portion 22 of the housing H. When the distance sensor module A is fixed to the underside of the cover 3 in this manner, the center of gravity line WL is set to maintain a vertical position due to the action of gravity, passing through the center of gravity W and the transmitting / receiving unit 12. When the manhole cover 3 of the manhole 2 is in a horizontal position with this setting, the attitude maintenance unit V supports the weight of the distance sensor S with the housing H, with the upper end of the pivot member 23 contacting the center position of the concave surface 15S of the support plate 15 at the support point P, and suspends the distance sensor S from the housing H in a stable position.

[0079] In contrast, if, for example, the manhole cover 3 of manhole 2 changes to an improper position, such as being tilted, the distance sensor module A will, with the protruding end of the pivot member 23 in contact with the inner surface of the concave surface 15S, pivot relative to the housing H with the support point P, which becomes the contact position due to the action of gravity, as the pivot center. This maintains a vertical position where the center of gravity line WL is aligned with the vertical direction, and the distance sensor S is maintained in a horizontal position. As a result, the direction of the detection signal sent from the transmitting / receiving surface 12S of the transmitting / receiving unit 12 is aligned with the vertical direction, and the water surface f is measured with high accuracy.

[0080] Distance sensor module A can be installed on bridges, riverbanks, and other facilities to measure river water levels. In such cases, the slope of the installation site or the horizontally extending steel poles used as installation locations may tilt over time, but distance sensor module A can compensate for this by allowing the distance sensor S to oscillate under its own weight. Distance sensor module A can also be attached to the underside of the lid of a septic tank or to the ceiling inside the tank to measure the water level inside the tank, and can also be used to measure water levels in rice paddies and hydroponic fields.

[0081] In particular, the distance sensor module A maintains that the distance sensor S is housed inside the sensor housing Hs even when the orientation of the distance sensor S relative to the housing H changes. Furthermore, when the orientation of the distance sensor S relative to the housing H changes, the pair of regulating arms 24 restrict the change in the orientation of the distance sensor S relative to the housing H, thus eliminating the inconvenience of the distance sensor S changing its orientation significantly relative to the housing H and coming into contact with the inner surface of the vertical outer wall 21.

[0082] The distance sensor module A is configured such that even when the tilt of the distance sensor S reaches its maximum, the amount of downward protrusion of the lower end of the vertical outer wall 21 (the lower end of the sensor housing Hs) does not protrude downward from the lower end of the vertical outer wall 21 in a side view (in a view perpendicular to the vertical direction Z). Therefore, the vertical outer wall 21 can protect the distance sensor S even in situations where a large impact is applied due to the weight of the manhole cover 3, such as when the manhole cover 3 of the manhole 2 equipped with the distance sensor module A is accidentally dropped to the ground.

[0083] Furthermore, in this distance sensor module A, even in situations where the distance sensor module A vibrates, such as when vibrations or shocks are transmitted from the outside, the cushioning member 17 suppresses large fluctuations between the housing H and the distance sensor S, thereby suppressing erroneous measurements.

[0084] Furthermore, the configuration in which a concave surface 15S (oscillating support VS) is formed on the lower surface of the plate portion 15a that opens downwards is open in the direction of gravity, so even if water droplets or dust enter the contact point between the pivot member 23 and the concave surface 15S, the water droplets or dust are expelled by gravity, thereby suppressing obstruction of the oscillation of the distance sensor S inside the sensor housing Hs of the housing H.

[0085] [Another embodiment] The present invention may also be configured as follows, in addition to the embodiments described above (parts having the same functions as the embodiments are given the same numbers and reference numerals as the embodiments).

[0086] (a) As shown in Figure 7, the attitude maintenance unit V comprises a pivot shaft 18 as a pivot point VA that protrudes downward from the lower surface of the support plate 15, and a concave portion 27 as a pivot receiving portion VS formed in the subwall portion 20a of the housing H and open to information, thereby constituting the distance sensor module A.

[0087] In this alternative embodiment (a), the pivot shaft 18 is shaped to taper towards the end, and the concave portion 27 has a V-shaped cross-section, becoming deeper in the center, and is formed as a rotating body around the center of gravity line WL. As a result, the lower end of the pivot shaft 18 comes into contact with the deepest part of the concave portion 27 due to gravity acting on the distance sensor S, and this contact point becomes the support point P.

[0088] In this alternative embodiment (a), the vertical relationship between the pivot shaft 18 and the concave portion 27 (concave surface 15S in the embodiment) is reversed compared to the embodiment, but similar to the embodiment, the distance sensor S is supported so as to be suspended from the housing H via the attitude maintenance unit V.

[0089] In this alternative embodiment (a), as in the embodiment, a cushioning member 17 made of rubber or a flexible resin is sandwiched between the lower surface of the support plate 15 and the sub-wall portion 20a. In this alternative embodiment (a), as in the embodiment, a pair of regulating arms 24 are used.

[0090] (b) As shown in Figure 8, the attitude maintenance unit V is configured as a distance sensor module A by providing a coil spring 30 as a support mechanism T that connects the lower surface of the upper wall 20 of the housing H and the upper end wall 13 of the sensor body 10 of the distance sensor S.

[0091] In this alternative embodiment (b), the housing H does not have the sub-wall portion 20a of the embodiment, and an upper support 31 projecting downward is provided at the center of the lower surface of the flat upper wall 20, and a lower support 32 is provided at the center of the upper end wall 13 of the sensor body portion 10.

[0092] The upper support 31 is cylindrical with its lower end opening downwards, and the lower support 32 is cylindrical with its upper end opening upwards. The coil spring 30 is provided in such a way that its upper end is fitted into the cylindrical portion of the upper support 31 and its lower end is fitted into the cylindrical portion of the lower support 32.

[0093] In this alternative embodiment (b), the distance sensor S is supported in a suspended state from the housing H by a coil spring 30, so that the center of gravity line WL of the distance sensor S is maintained in a vertical position regardless of the orientation of the housing H.

[0094] (c) Instead of the coil spring 30 shown in the alternative embodiment (b), a string-like body made of synthetic fibers or a flexible wire can be used as the support mechanism T.

[0095] (d) As a distance sensor S, it is possible to use ultrasound as the detection signal, or to use light rays such as infrared or visible light as the detection signal. [Industrial applicability]

[0096] This invention can be used in distance sensors. [Explanation of Symbols]

[0097] 3. Lid (to be installed) 10 Sensor main unit 12 Transmitter / Receiver 15 Support plate 15S Concave surface (rocking support part) 17. Cushioning material 18. Pivot axis (oscillating pivot) 22 Mounting part 23. Pivot Member (Oscillating Pivot) 24 Regulatory arm (regulatory section) 27 Concave part (rocking support part) 30. Coil spring (support mechanism) A Distance sensor module H cabinet Hs sensor housing R Regulation Department S distance sensor T support mechanism W Center of gravity

Claims

1. It consists of a distance sensor and a housing, The distance sensor comprises a sensor body and a transmitting / receiving unit connected to the sensor body, and is configured as a non-contact type that measures the distance to the object to be measured by the sensor body when a detection signal transmitted from the transmitting / receiving unit is reflected by the object to be measured and then received by the transmitting / receiving unit. The housing has a sensor housing section for housing the distance sensor and a mounting section for attaching the sensor housing section to an external mounting target. The distance sensor is supported in a manner that it is suspended from the housing via a support plate. The support plate and the housing are configured to make point contact with each other through their curved surfaces. When the mounting portion of the sensor housing is attached to the mounting object, the sensor housing is maintained in a position where the detection direction of the transmitting and receiving unit is directed vertically downward due to the action of gravity. The sensor housing unit houses the distance sensor so that it can change its posture within a preset range. The distance sensor is housed in the sensor housing in a manner that allows its orientation to change by swinging relative to the housing. The distance sensor and the housing have a pivot point, and the other of the distance sensor and the housing has a pivot support that supports the pivot point. Of the pivot point and the center of the pivot support, the one that the distance sensor has is located vertically above the center of gravity of the distance sensor. The mounting portion has a pivot point that protrudes upward and whose diameter decreases towards the upper end, The distance sensor module has a pivoting receiving portion which is a concave surface that is in contact with the upper end of the pivoting pivot point and is open downwards.

2. It consists of a distance sensor and a housing, The distance sensor comprises a sensor body and a transmitting / receiving unit connected to the sensor body, and is configured as a non-contact type that measures the distance to the object to be measured by the sensor body when a detection signal transmitted from the transmitting / receiving unit is reflected by the object to be measured and then received by the transmitting / receiving unit. The housing has a sensor housing section for housing the distance sensor and a mounting section for attaching the sensor housing section to an external mounting target. The distance sensor is supported in a manner that it is suspended from the housing via a support plate. The support plate and the housing are configured to make point contact with each other through their curved surfaces. When the mounting portion of the sensor housing is attached to the mounting object, the sensor housing is maintained in a position where the detection direction of the transmitting and receiving unit is directed vertically downward due to the action of gravity. The sensor housing unit houses the distance sensor so that it can change its posture within a preset range. The distance sensor is housed in the sensor housing in a manner that allows its orientation to change by swinging relative to the housing. The distance sensor and the housing have a pivot point, and the other of the distance sensor and the housing has a pivot support that supports the pivot point. Of the pivot point and the center of the pivot support, the one that the distance sensor has is located vertically above the center of gravity of the distance sensor. The distance sensor has a pivot point that protrudes downward and whose diameter decreases towards the lower end, A distance sensor module having a mounting portion which is a sway receiving portion that is a concave surface that abuts against the lower end of the sway pivot point and is open upward.

3. The distance sensor module according to claim 1 or 2, wherein the transmitting and receiving unit is arranged to face the object to be measured, and the center of gravity of the distance sensor is located on the central axis of the transmitting and receiving unit.

4. The distance sensor module according to claim 1 or 2, wherein the amount of downward protrusion of the lower end position of the sensor housing is set such that when the distance sensor changes its orientation within a preset range, the distance sensor is not exposed from the lower end of the sensor housing in a side view.

5. The distance sensor module according to claim 1 or 2, further comprising a regulating unit that determines the limit of the change in the attitude of the distance sensor relative to the sensor housing unit.

6. The distance sensor module according to claim 1 or 2, further comprising a fixing member for fixing the distance sensor housed in the sensor housing so that its orientation cannot be changed.

7. The distance sensor module according to claim 1 or 2, further comprising a buffer member arranged to contact the housing and the distance sensor, and which suppresses the propagation of vibrations of the mounting portion to the distance sensor.

8. The distance sensor module according to claim 1 or 2, further comprising a buffer member that contacts the housing and the distance sensor and is arranged in a region surrounding the pivot point.

9. The distance sensor module according to claim 1 or 2, wherein the distance sensor is configured as a millimeter-wave radar sensor using millimeter waves as the detection signal, and the portion of the distance sensor covering the transmitting and receiving unit is made of an insulator.

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