Sensor Device

Abstract

To provide a sensor device capable of improving omnidirectivity within 360 degrees around a sensor element while protecting the sensor element from the outside.SOLUTION: A sensor device (1) includes: sensor elements (3, 4) having a temperature sensing resistor; and a protection cover (2) for protecting the sensor elements. The sensor elements are extended longer in one direction, and the protection cover surrounds the periphery of the sensor elements by plural posts (13) extended obliquely relative to a longitudinal direction of the sensor elements. The plural posts preferably cross in a lattice shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sensor device capable of measuring, for example, wind speed. [Background technology]

[0002] A thermal sensor device is known that exposes a heated flow rate detection resistor element to a fluid and detects the flow rate of the fluid based on the heat dissipation effect of the exposed element. The sensor device includes a temperature compensation resistor element in addition to the flow rate detection resistor element, and the flow rate detection resistor element and the temperature compensation resistor element are incorporated in a bridge circuit. When the flow rate detection resistor element receives a fluid, the temperature of the flow rate detection resistor element decreases and the resistance changes, which allows a differential output to be obtained in the bridge circuit. The flow rate of the fluid can be detected based on this differential output.

[0003] For example, in Patent Document 1, each sensor element including a flow rate detection resistive element and a temperature compensation resistive element is supported separately from an insulating substrate via a lead wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-215163 A [Patent Document 2] Japanese Patent Application Publication No. 10-239169 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the sensor device disclosed in Patent Document 1, no protective cover is provided for protecting the sensor element from external contact, and the sensor element is exposed to the outside.

[0006] To cope with this problem, a structure in which a protective cover is placed around the sensor element has been considered, but this has the problem that, depending on the direction of the fluid flow, the detection accuracy is reduced due to the influence of the protective cover before the fluid reaches the sensor element.

[0007] Furthermore, the structure of the sensor device shown in Patent Document 1 is originally intended to improve the accuracy of flow rate detection from a specific direction, and is not intended to obtain omnidirectionality in the 360-degree area around the sensor element.

[0008] Patent Document 2 discloses a temperature sensor in which a cap is placed over a temperature sensor element, but the sensor is not intended to be used for flow rate detection, much less is it designed to be omnidirectional in the 360-degree area around the temperature sensor element.

[0009] Therefore, the present invention has been made in consideration of the above problems, and has an object to provide a sensor device that can protect a sensor element from the outside and improve omnidirectionality in 360 degrees around the sensor element. [Means for solving the problem]

[0010] The flow sensor device of the present invention is a sensor device having a sensor element equipped with a temperature sensitive resistor and a protective cover for protecting the sensor element, the sensor element having a shape that extends long in one direction, and the protective cover surrounds the periphery of the sensor element with a plurality of supports that extend in a diagonal direction with respect to the longitudinal direction of the sensor element. The plurality of support columns are arranged in a lattice pattern, and an intersection of the plurality of support columns and the sensor element overlap at one point in a side view. It is characterized by:

[0011] The flow sensor device of the present invention is a sensor device having a sensor element equipped with a temperature sensitive resistor and a protective cover for protecting the sensor element, the sensor element being supported on a substrate, the temperature sensitive resistor being formed over the entire periphery of the sensor element, and the protective cover surrounding the periphery of the sensor element with a plurality of supports extending in a diagonal direction with respect to the direction in which the sensor element is arranged as viewed from the substrate. The plurality of support columns are arranged in a lattice pattern, and an intersection of the plurality of support columns and the sensor element overlap at one point in a side view. It is characterized by: Effect of the Invention

[0012] In the sensor device of the present invention, the sensor element can be protected from the outside, and the omnidirectionality in the 360-degree area around the sensor element can be improved. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a sensor device according to a first embodiment. [Diagram 2] FIG. 2 is a front view of the sensor device according to the first embodiment. [Diagram 3] FIG. 2 is a side view of the sensor device according to the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view of the sensor element of the present embodiment. [Diagram 5] 1 is a circuit diagram of a sensor device according to an embodiment of the present invention. [Figure 6] 3 is a cross-sectional view taken along line AA of the protective cover shown in FIG. 2. [Figure 7] FIG. 2 is an exploded perspective view of the sensor device shown in FIG. [Figure 8] 8 is a partially enlarged front view showing a part of FIG. 7. [Figure 9] FIG. 11 is a perspective view showing a protective cover according to a second embodiment. [Figure 10] FIG. 11 is a perspective view showing a protective cover according to a third embodiment. [Figure 11] FIG. 11 is a perspective view showing a protective cover according to a fourth embodiment. [Figure 12] FIG. 2 is a perspective view showing a protective cover of Comparative Example 1. [Figure 13] FIG. 11 is a perspective view showing a protective cover of Comparative Example 2. [Figure 14] 4 shows the results of an experiment conducted using the sensor device of Example 1, showing the relationship between wind speed and angular directivity characteristics. [Figure 15] 11 shows the results of an experiment conducted using the sensor device of Example 2, showing the relationship between wind speed and angular directivity characteristics. [Figure 16]13 shows the results of an experiment conducted using the sensor device of Example 3, showing the relationship between wind speed and angular directivity characteristics. [Figure 17] 13 shows the results of an experiment conducted using the sensor device of Example 4, showing the relationship between wind speed and angular directivity characteristics. [Figure 18] 13 is a graph showing the results of an experiment conducted using the sensor device of Comparative Example 1, showing the relationship between wind speed and angular directivity characteristics. [Figure 19] 13 is a result of an experiment conducted using a sensor device of Comparative Example 2, showing the relationship between wind speed and angular directivity characteristics. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the present invention (hereinafter, abbreviated as "embodiment") will be described in detail below. Note that the present invention is not limited to the following embodiment, and can be practiced in various modifications within the scope of the gist of the present invention.

[0015] <Description of the Sensor Device According to the First Embodiment> FIG. 1 is a side view of the sensor device in the first embodiment. FIG. 2 is a front view of the sensor device in the first embodiment. FIG. 3 is a side view of the sensor device in the first embodiment. FIG. 4 is a cross-sectional view of a sensor element in the present embodiment. FIG. 5 is a circuit diagram of the sensor device in the present embodiment. FIG. 6 is a cross-sectional view of the protective cover shown in FIG. 2 taken along line AA.

[0016] (Overview of sensor device 1) The X1-X2 direction and the Y1-Y2 direction shown in FIG. 1 indicate two perpendicular directions within a plane, and the Z1-Z2 direction shown in FIG. 1 indicates a height direction perpendicular to the X1-X2 direction and the Y1-Y2 direction.

[0017] A sensor device 1 according to the first embodiment shown in FIG. 1 includes sensor elements 3 and 4 each having a temperature sensitive resistor, and a protective cover 2 for protecting the sensor elements 3 and 4 from the outside.

[0018] In the following, in the first embodiment and other embodiments described later, the above-mentioned planes and height directions are defined based on the posture of the sensor device 1 shown in Fig. 1. In other words, the basic posture will be described as a state in which the sensor device 1 is upright so that the protective cover 2 is located above the sensor device 1. As shown in FIGS. 1 to 3, sensor elements 3 and 4 are disposed inside a protective cover 2 having a mesh structure.

[0019] 1 to 3, the sensor elements 3 and 4 are formed in a shape that extends long in the height direction (Z1-Z2 direction). In this way, the sensor elements 3 and 4 are rod-shaped, and specifically, may be cylindrical or polygonal prism-shaped. Here, the sensor elements 3 and 4 in this embodiment are cylindrical and extend long in the height direction.

[0020] As shown in FIG. 2, each of the sensor elements 3 and 4 has lead wires 6a, 6b, 8a, and 8b connected to both ends thereof, and each lead wire is connected to a substrate 9 (see FIG. 7). The sensor element 3 is a first sensor element having a flow rate detecting resistor 10, and the sensor element 4 is a second sensor element having a temperature compensating resistor .

[0021] The internal structure of the first sensor element 3 will be described with reference to Fig. 4. As shown in Fig. 4, the first sensor element 3 includes a flow rate detection resistor 10 as a temperature sensitive resistor, electrode caps 11 disposed on both sides of the flow rate detection resistor 10, and an insulating film 12 that covers the flow rate detection resistor 10 and the electrode caps 11.

[0022] The flow rate detection resistor 10 is formed by forming a resistive coating on the surface of a cylindrical substrate such as ceramic. Therefore, the flow rate detection resistor (temperature sensitive resistor) 10 is formed over the entire periphery. Here, "overall periphery" refers to the direction around an axis centered on the height direction (Z1-Z2 direction) in which the first sensor element 3 extends. Although not shown, the surface of the resistive coating of the flow rate detection resistor 10 is trimmed to adjust the resistance. The outer surface of the first sensor element 3 includes an element surface 5a that functions as a flow rate sensing surface, and an upper surface 5b and a lower surface 5c located above and below the element surface 5a.

[0023] As shown in Fig. 4, the first lead wire 6a extends in the Z2 direction from the electrode cap 11 located on the lower surface 5c side. The first lead wire 6b extends in the Z1 direction from the electrode cap 11 located on the upper surface 5b side, is bent midway, and extends in the Z2 direction. Therefore, as shown in Fig. 4, the pair of lead wires 6a, 6b face each other with a predetermined gap in the X1-X2 direction, and both extend in the Z2 direction. The ends of the pair of lead wires 6a, 6b are connected to the substrate 9. The second sensor element 4 has the same structure as that shown in FIG. 4, but instead of the flow rate detecting resistor 10, a temperature compensating resistor 38 is built in as a temperature sensitive resistor.

[0024] As shown in Fig. 5, the flow rate detecting resistor 10 and the temperature compensating resistor 38 form a bridge circuit. As shown in Fig. 5, the flow rate detecting resistor 10, the temperature compensating resistor 38, and resistors 16 and 17 form a bridge circuit 18. As shown in Fig. 5, the flow rate detecting resistor 10 and the resistor 16 form a first series circuit 19, and the temperature compensating resistor 38 and the resistor 17 form a second series circuit 20. The first series circuit 19 and the second series circuit 20 are connected in parallel to form the bridge circuit 18.

[0025] 5, an output part 21 of the first series circuit 19 and an output part 22 of the second series circuit 20 are each connected to a differential amplifier (amplifier) ​​23. A feedback circuit 24 including the differential amplifier 23 is connected to the bridge circuit 18. The feedback circuit 24 includes a transistor (not shown) and the like.

[0026] The resistors 16 and 17 have a smaller temperature coefficient of resistance (TCR) than the flow rate detecting resistor 10 and the temperature compensating resistor 38. The flow rate detecting resistor 10 has a predetermined resistance value Rs1 in a heated state controlled to be higher than a predetermined ambient temperature by a predetermined value, and the temperature compensating resistor 38 is controlled to have a predetermined resistance value Rs2 at the ambient temperature. The resistance value Rs1 is smaller than the resistance value Rs2. The resistor 16 constituting the first series circuit 19 with the flow rate detecting resistor 10 is, for example, a fixed resistor having a resistance value R1 similar to the resistance value Rs1 of the flow rate detecting resistor 10. The resistor 17 constituting the second series circuit 20 with the temperature compensating resistor 38 is, for example, a fixed resistor having a resistance value R2 similar to the resistance value Rs2 of the temperature compensating resistor 38.

[0027] The flow rate detection resistor 10 is adjusted to have a temperature higher than the ambient temperature, and when the first sensor element 3 receives wind, the temperature of the flow rate detection resistor 10, which is a heating resistor, drops. This causes the potential of the output section 21 of the first series circuit 19 to which the flow rate detection resistor 10 is connected to fluctuate. This causes a differential output to be obtained by the differential amplifier 23. Then, the feedback circuit 24 applies a drive voltage to the flow rate detection resistor 10 based on the differential output. Then, based on the change in the voltage required to heat the flow rate detection resistor 10, the microcomputer 30 (see FIG. 7) arranged in the substrate 9 can convert and output the wind speed. The microcomputer is electrically connected to each of the sensor elements 3 and 4 via the respective lead wires 6a, 6b, 8a, and 8b.

[0028] In addition, the temperature compensating resistor 38 detects the temperature of the fluid itself and compensates for the effect of temperature changes of the fluid. In this way, by providing the temperature compensating resistor 38, the effect of temperature changes of the fluid on flow rate detection can be reduced, and flow rate detection can be performed with high accuracy. As described above, the temperature compensating resistor 38 has a resistance sufficiently higher than that of the flow rate detection resistor 10, and its temperature is set to be close to the ambient temperature. Therefore, even if the temperature compensating resistor 38 is exposed to wind, the potential of the output section 22 of the second series circuit 20 to which the temperature compensating resistor 38 is connected hardly changes. Therefore, a differential output based on the resistance change of the flow rate detection resistor 10 can be obtained with high accuracy by using the potential of the output section 22 as a reference potential. It should be noted that the circuit configuration shown in FIG. 5 is merely an example and is not limited to this.

[0029] (Protective cover 2) As shown in FIG. 1, the protective cover 2 is composed of a peripheral portion 2a that surrounds the sensor elements 3 and 4, a ceiling portion 2b located above the peripheral portion 2a (Z1 side), and a fixed support portion 2c located below the peripheral portion 2a (Z2 side).

[0030] The peripheral portion 2a of the protective cover 2 surrounds the sensor elements 3, 4 with a plurality of support posts 13 extending in a diagonal direction relative to the longitudinal direction (Z1-Z2 direction) of the sensor elements 3, 4, and has a plurality of through holes 15. In the first embodiment, the plurality of support posts 13 intersect in a lattice pattern.

[0031] Each support pillar 13 is inclined while being twisted from the fixed support part 2c to the ceiling part 2b, and connects the ceiling part 2b and the fixed support part 2c. Each support pillar 14 is composed of two patterns in which the inclination direction differs by about 90 degrees, and the support pillars 14 of each pattern intersect in a lattice shape from an oblique direction.

[0032] In the peripheral portion 2a, the portion other than the support pillars 13 is a through hole 15, and the shape (outline) of each through hole 15 is a rhombus or a rectangle. Through the through hole 15, the sensor elements 3, 4 located inside the protective cover 2 can be seen from the outside. FIG. 2 is a front view seen from the direction of an arrow A in FIG. 1, and FIG. 3 is a side view seen from the direction of an arrow B in FIG. 1, and in both cases, the sensor elements 3, 4 appear through the through hole 15. Even when viewed from an angle other than that of FIG. 2 and FIG. 3, the sensor elements 3, 4 appear through the through hole 15. This is because the support pillars 13 constituting the protective cover 2 extend in an oblique direction with respect to the longitudinal direction (Z1-Z2 direction) of the sensor elements 3, 4.

[0033] Therefore, when wind acts from 360-degree directions around the sensor elements 3 and 4, in other words, when wind acts from 360-degree directions in a horizontal plane consisting of the X1-X2 and Y1-Y2 directions, the wind passes through the through-hole 15 of the peripheral portion 2a and acts on the first sensor element 3 including the flow detection resistor 10, regardless of the direction from which the wind blows. Therefore, the first sensor element 3 can detect the flow rate by the action of wind from 360 degrees around. As described above, in the sensor device 1 of the first embodiment, the sensor elements 3 and 4 can be appropriately protected from the outside, and the omnidirectionality of the sensor elements 3 and 4 in the 360-degree surroundings can be improved. In the first embodiment, the multiple support columns 13 intersect in a lattice pattern, which can increase the strength of the protective cover 2.

[0034] Furthermore, it is preferable that the following configuration is provided. (1) In side view, intersections 13a at which the multiple struts 13 intersect deviate from center C of first sensor element 3 at all angles in the circumferential direction (see FIGS. 2 and 3).

[0035] As shown in the front view and side view of Figures 2 and 3, the intersection 13a is offset upward (Z1 side) or downward (Z2 side) from the center C of the first sensor element 3. The same is true for surrounding angles other than those of Figures 2 and 3. This allows wind to act appropriately on the first sensor element 3 from any direction within 360 degrees, and more effectively improves omnidirectionality within 360 degrees.

[0036] (2) The width T of the support 13 is shorter than the length dimension L1 in the longitudinal direction (Z1-Z2 direction) of the first sensor element 3 (see FIG. 2 and FIG. 8 described later). In this way, by narrowing the width T of the support 13, the overlapping area between the first sensor element 3 and the support 13 in a side view can be reduced, thereby effectively improving omnidirectionality. In this embodiment, the overlapping area of ​​the support 13 with the first sensor element 3 is preferably 75% or less, more preferably 65% ​​or less, even more preferably 60% or less, even more preferably 55% or less, and most preferably 50% or less, regardless of the surrounding angle from which the sensor element 3 is overlapped.

[0037] (3) The length dimension (thickness dimension) L2 from the outside to the inside of the support 13 is longer than the width T of the support 13 (see FIG. 6). Here, "the inside of the support pillar 13" refers to the inner side of the protective cover 2 on which the sensor elements 3 and 4 are arranged, and "the outside of the support pillar 13" refers to the opposite side (the outer side of the protective cover 2).

[0038] Fig. 6 is a cross-sectional view taken along line AA in Fig. 2. As shown in Fig. 6, the length dimension L2 of the support pillar 13 is longer than the width dimension T. This makes it difficult for the support pillar 13 to block wind blowing from the outside of the protective cover 2 toward the inside of the protective cover 2, in other words, it is possible to reduce the range of wind directions that directly hit the support pillar 13. This makes it possible to effectively improve omnidirectionality in a 360-degree surrounding area. In addition, in a configuration in which the width T changes from the outside to the inside of the support 13 as in FIG. 6, the maximum width is compared with the length dimension (length dimension) L2 of the support 13.

[0039] (4) The support pillars 13 are formed with a protruding cross-sectional shape whose width dimension gradually decreases from the inside to the outside (see FIG. 6). As shown in FIG. 6, by making the cross-sectional shape such that the protrusion faces outward, wind can pass smoothly through the side of the support 13 from the outside to the inside, thereby effectively improving omnidirectionality in a 360-degree surrounding area.

[0040] The ceiling portion 2b located above the surrounding portion 2a will be described. As shown in FIG. 1, the ceiling portion 2b has a structure including a ring portion 25 connecting each of the pillars 13 constituting the surrounding portion 2a and two arch-shaped supports 26 intersecting above the ring portion 25, but is not limited to this structure. However, by having the ceiling portion 2b, the strength of the protective cover 2 can be increased. By providing the supports 26, the strength of the protective cover 2 can be improved. In this case, by arranging the pillar-shaped supports 26 so as to cover the entire ceiling portion 2b and making the areas other than the supports 26 into spaces that lead to the inside of the protective cover 2, it is considered that the effect of the airflow from diagonally above on the detection accuracy of the 360 ​​degrees around can be weakened.

[0041] The fixed support portion 2c will be described below. In describing the fixed support portion 2c, the inner structure of the fixed support portion 2c is important, so that Figs. 7 and 8 will be used below. Fig. 7 is an exploded perspective view of the sensor device shown in Fig. 1. Fig. 8 is a partially enlarged front view showing a part of Fig. 7 in an enlarged manner.

[0042] 7, the protective cover 2 can be divided into a first part 2d and a second part 2e, and by combining these parts 2d and 2e, the protective cover 2 that surrounds the sensor elements 3 and 4 can be configured. The parts 2d and 2e have the same shape and are molded from resin using a mold.

[0043] 7 and 8, the first part 2d has a recessed storage section 27 formed inside the fixed support section 2c. The storage section 27 is divided into a first storage section 27a, a second storage section 27b, and a third storage section 27c, which are connected to each other.

[0044] The substrate 9 to which the sensor elements 3 and 4 are connected can be stored in each of the storage sections 27a to 27c of the fixed support section 2c. The second part 2e also has a storage section 27 similar to that of the first part 2d, and by combining the parts 2d and 2e, the substrate 9 can be reliably fixed and supported within the fixed support section 2c.

[0045] 7 and 8, a plurality of fine holes 29 are provided on the upper surface of the fixed support part 2c, and these fine holes 29 lead to the storage part 27. Therefore, as shown in Fig. 8, the lead wires 6a, 6b, 8a, and 8b for fixing the sensor elements 3 and 4 can be passed through these fine holes 29. This allows the substrate 9 to be stored inside the fixed support part 2c, and the sensor elements 3 and 4 to be arranged apart from each other above (Z1 side) the upper surface of the fixed support part 2c.

[0046] As shown in Fig. 7, the support 26 provided on the ceiling 2b of the protective cover 2 is formed with a claw portion 26a and a concave claw receiving portion 26b. The fixed support portion 2c is provided with a fitting protrusion 28a and a fitting hole portion 28b located on the opposite side to the fitting protrusion 28a. As a result, when the parts 2d and 2e are combined, the parts 2d and 2e can be joined by inserting the claw portion 26a of the ceiling 2b into the claw receiving portion 26b and further fitting the fitting protrusion 28a into the fitting hole portion 28b. This makes it possible to prevent the pair of parts 2d and 2e from coming off even due to an external impact, and to appropriately protect the sensor elements 3 and 4.

[0047] (Sensor elements 3 and 4) A supplementary note on the sensor elements 3 and 4. As shown in FIG. 8, the first sensor element 3 is preferably disposed at a higher position than the second sensor element 4. That is, the first sensor element 3 is preferably located farther away from the upper surface 2f of the fixed support portion 2c than the second sensor element 4. Furthermore, the first sensor element 3 is preferably formed at a higher position than the lead wire 8b connected to the second sensor element 4. This can weaken the influence of the second sensor element 4 and further the lead wire 8b when wind acts on the first sensor element 3, and can effectively improve omnidirectionality in a 360-degree surrounding area.

[0048] It is also preferable to arrange the sensor elements 3, 4 and the lead wires 6a, 6b, 8a, 8b in a line. As a result, the second sensor element 4 and the lead wires are arranged in only one direction (X1-X2 direction as shown in FIG. 7) when viewed from the first sensor element 3, and when wind acts on the first sensor element 3, the angle range affected by the second sensor element 4 and the lead wire 8b can be narrowed as much as possible, effectively improving omnidirectionality in the 360-degree surroundings.

[0049] Moreover, the first sensor element 3 is preferably located approximately at the center of the upper surface 2f of the fixed support portion 2c. In other words, the first sensor element 3 is preferably disposed at a position approximately equidistant from the peripheral portion 2a of the protective cover 2. This makes it easier for wind to act around the first sensor element 3 when it acts from all around 360 degrees, effectively improving omnidirectionality in the 360-degree surroundings.

[0050] (Substrate 9) The substrate 9 that supports the sensor elements 3 and 4 will now be described. The substrate 9 is an insulating substrate, and although there is no particular limitation, it is preferably a general printed circuit board made of glass cloth impregnated with epoxy resin, and for example, an FR4 substrate can be presented.

[0051] As shown in Figures 7 and 8, the substrate 9 has a sensor portion 9a that supports the sensor elements 3 and 4, a drive substrate 9b on which the microcontroller 30, connectors 36, 37, etc. are mounted, and a connecting portion 9c that connects the sensor portion 9a and the drive substrate 9b.

[0052] The first storage section 27a formed in the fixed support section 2c of the protective cover 2 is formed with a size capable of storing the sensor section 9a, the second storage section 27b is formed with a size capable of storing the drive board 9b, and the third storage section 27c is formed with a size capable of storing the connecting section 9c.

[0053] As shown in Figures 7 and 8, the sensor portion 9a has a plurality of holes 31 formed in a horizontal row, and the lead wires 6a, 6b, 8a, and 8b connected to the sensor elements 3 and 4 are inserted into the holes 31 and fixed.

[0054] As shown in Figs. 7 and 8, the width of the connecting portion 9c is smaller than the width of the sensor portion 9a and the driving substrate 9b. This makes it difficult for heat generated in the driving substrate 9b to reach the sensor portion 9a and, in turn, the sensor elements 3 and 4. This makes it possible to maintain good detection accuracy. In addition, a slit 32 is formed in the sensor portion 9a closer to the connecting portion 9c, which separates the heat sources of the sensor portion 9a and the driving substrate 9b. As a result, it is possible to weaken the thermal effect from the driving substrate 9b to the sensor portion 9a, and improve the sensor responsiveness.

[0055] (Assembly of the sensor device) In the first embodiment, the substrate 9 having the sensor elements 3 and 4 is stored in the storage section 27 of the pair of parts 2d and 2e constituting the protective cover 2 shown in Fig. 7, and the parts 2d and 2e are assembled and joined. Next, a pair of cases 33 and 34 are assembled at the bottom end of the protective cover 2 to cover the driving substrate 9b, and fastened with screws 35. This completes the sensor device 1 shown in Fig. 1.

[0056] <Description of the sensor device according to the second embodiment> The following describes sensor devices other than those of the first embodiment. However, since the device body (including the sensor elements 3 and 4, the substrate 9, and the cases 33 and 34) excluding the protective cover has the same structure as that of the first embodiment, only the protective cover will be described in the following embodiments.

[0057] As shown in FIG. 9, the protective cover 40 applied to the sensor device of the second embodiment includes a plurality of support columns 41 extending obliquely with respect to the height direction (Z1-Z2 direction) which is the longitudinal direction of the sensor elements 3 and 4. The protective cover 40 has the support columns 41 extending from the side to the top. A hole 42 is formed at the apex, and the support column 41 may extend to cover this portion. The protective cover 40 has a plurality of through holes 43 formed from the side to the top, and the through holes 43 are substantially diamond-shaped. The protective cover 40 shown in FIG. 9 is different from the protective cover 2 shown in the first embodiment in that a cap member of a substantially constant thickness in which the through holes 43 are blocked is produced, and then a plurality of diamond-shaped through holes 43 are formed by punching on the side of the cap part. Also, the protective cover 40 of the second embodiment cannot be divided into a plurality of parts as shown in FIG. 7, and is a type in which the protective cover 40 is fitted from above the device body.

[0058] 9, multiple support columns 41 also extend obliquely with respect to the height direction (Z1-Z2 direction) which is the longitudinal direction of sensor elements 3 and 4, and intersect in a lattice pattern. Therefore, by applying protective cover 40 of the second embodiment, sensor elements 3 and 4 can be protected from the outside, and omnidirectionality in a 360-degree surrounding area can be improved.

[0059] In this embodiment as well, it is preferable that the intersections of the multiple struts 41 are offset from the center C (see FIGS. 2 and 3) of the first sensor element 3 in all angles in the circumferential direction in side view.

[0060] <Description of the Sensor Device According to the Third Embodiment> The protective cover 50 shown in the third embodiment in Fig. 10 is different from that in Fig. 9 in that the through holes 53 are substantially circular, but otherwise has the same structure as that in Fig. 9. The protective cover 50 shown in Fig. 10 also has a mesh structure in which a plurality of supports 51 extend in the height direction (Z1) that is the longitudinal direction of the sensor elements 3, 4 and in the diagonal direction. Therefore, by applying the protective cover 50 of the third embodiment, the sensor elements 3, 4 can be protected from the outside, and the omnidirectionality in a 360-degree surrounding area can be improved.

[0061] In this embodiment as well, it is preferable that the intersections of the multiple struts 51 are offset from the center C (see FIGS. 2 and 3) of the first sensor element 3 in all angles in the circumferential direction in side view.

[0062] <Description of the sensor device according to the fourth embodiment> A protective cover 60 according to a fourth embodiment shown in FIG. 11 is provided with a plurality of spiral pillars 61 connecting between a ring portion 62 at the upper end and a fixed support portion 64 at the lower end. These pillars 61 extend obliquely with respect to the height direction (Z1-Z2 direction) which is the longitudinal direction of the sensor elements 3 and 4. Therefore, by applying the protective cover 60 according to the fourth embodiment, the sensor elements 3 and 4 can be protected from the outside, and omnidirectionality in a 360-degree surrounding area can be improved. Note that, in order to increase the strength of the protective cover 60, a mesh structure as shown in FIGS. 1 to 3 is preferable.

[0063] <Comparison with Comparative Examples> In contrast, protective covers 70, 80 provided in sensor devices of comparative examples shown in Figs. 12 and 13 have supports 71, 81 extending in the height direction (Z1-Z2 direction), which is the longitudinal direction of sensor elements 3, 4. Comparative example 1 of Fig. 12 has a structure in which multiple supports 71, 72 intersect vertically and horizontally in a lattice pattern. Of these, support 71 extends in the height direction (Z1-Z2 direction). Moreover, in comparative example 2 of Fig. 13, multiple supports 81, 82 are arranged so that through holes 83 are staggered. Of these, support 81 extends in the height direction (Z1-Z2 direction).

[0064] Using the sensor devices of the above-mentioned embodiments and a sensor device of a comparative example, experiments were conducted on flow rate detection when wind was applied from 360 degrees around. In all experiments, the same device body to which the protective cover was attached was used. The experiments using the sensor devices 1 of the first to fourth embodiments will be described as "Example 1" to "Example 4".

[0065] The 360 ​​degrees around the circumference is a horizontal direction parallel to a plane formed by the X1-X2 direction and the Y1-Y2 direction shown in Fig. 1. This horizontal direction is a radial direction of the first sensor element 3 standing upright in the Z1-Z2 direction.

[0066] In the experiment, wind was applied to each sensor device from all sides. The wind speed was controlled by controlling the inverter's motion frequency to four levels: 3Hz, 7Hz, 10Hz, and 14Hz. The higher the motion frequency, the higher the wind speed. These wind speeds were measured by each sensor device.

[0067] The experimental results of Example 1 are shown in Fig. 14. As shown in Fig. 14, the numbers on the periphery of a circular graph simulating a wind rose indicate the direction of the wind toward the sensor device 1 located at the center.

[0068] The numbers 0, 2, 6, 8, 10, and 12 in the pie chart are wind speed values. The thick curves in the pie chart are the actual wind speed values ​​measured when the inverter's motion frequency was adjusted to 3 Hz, 7 Hz, 10 Hz, and 14 Hz and the wind from 360 degrees around was measured with a sensor device. Figure 14 also shows the ideal value as the ideal measurement value when the inverter's motion frequency is adjusted to 14 Hz.

[0069] Similarly to the above, wind speeds were measured from 360 degrees around for Examples 2 to 4 and Comparative Examples 1 and 2. The experimental results for Example 2 are shown in Fig. 15, those for Example 3 in Fig. 16, those for Example 4 in Fig. 17, those for Comparative Example 1 in Fig. 18, and those for Comparative Example 2 in Fig. 19.

[0070] As shown in FIG. 18, in Comparative Example 1, it was found that the air flow detection accuracy was extremely reduced in the directions of approximately 30 degrees to approximately 70 degrees, approximately 115 degrees to approximately 140 degrees, approximately 200 degrees to approximately 240 degrees, and approximately 270 degrees to approximately 320 degrees.

[0071] Furthermore, as shown in FIG. 19, in Comparative Example 2, it was found that the air volume detection accuracy was extremely reduced in the directions of approximately 30 degrees to approximately 50 degrees, approximately 60 degrees to approximately 90 degrees, approximately 100 degrees to approximately 120 degrees, approximately 130 degrees to approximately 150 degrees, approximately 160 degrees to approximately 180 degrees, approximately 200 degrees to approximately 220 degrees, approximately 230 degrees to approximately 250 degrees, approximately 270 degrees to approximately 290 degrees, approximately 310 degrees to approximately 340 degrees, and approximately 350 degrees to approximately 10 degrees.

[0072] In Comparative Examples 1 and 2, the reason why the wind volume detection accuracy decreases within the above angle range is thought to be that, when viewed from the side at that angle, the vertical direction (Z1-Z2 direction), which is the longitudinal direction of the first sensor element 3, roughly coincides with the support pillar, and the wind does not properly reach the first sensor element.

[0073] In contrast, in Examples 1 to 4, as shown in Figs. 14 to 17, no significant decrease in the air flow detection accuracy was observed for wind from any angle, compared to Comparative Examples 1 and 2, and the accuracy approached the ideal value.

[0074] In Examples 1 to 4, the multiple pillars surrounding the sensor elements 3 and 4 extend in a diagonal direction relative to the height direction (Z1-Z2 direction), which is the longitudinal direction of the sensor elements. Therefore, the pillars and the longitudinal direction of the first sensor element 3 do not overlap in a side view at any angle. Therefore, the wind can be appropriately applied to the first sensor element 3 at all angles in the circumferential direction, and omnidirectionality in a 360-degree circumference can be improved.

[0075] Among Examples 1 to 4, Example 3 shown in FIG. 16 had slightly lower wind flow detection accuracy in the directions of about 0 degrees to 80 degrees and about 230 degrees to 350 degrees than Examples 1, 2, and 4. Also, among Examples 1 and 2 in which multiple pillars intersect in a lattice pattern, Example 1 had better wind flow detection accuracy in the directions of about 190 degrees to about 150 degrees than Example 2. This shows that Example 1 is excellent in omnidirectionality in a 360-degree circumference as well as in the strength of the protective cover. Note that Example 1 meets all of the above conditions (1) to (4).

[0076] <Other embodiments> As another embodiment, the first sensor element 3 including the flow rate detection resistor can be applied in a form other than the one that extends long in one direction. However, the first sensor element 3 is provided with a flow rate detection resistor formed over the entire periphery of the sensor element under the condition that the flow rate detection resistor is formed over the entire periphery of the sensor element. For example, the first sensor element can be a spherical sensor element. Specifically, in a structure in which the flow rate detection resistor is formed over the entire surface of a spherical base, the flow rate detection resistor is formed over the entire periphery of the sensor element.

[0077] The first spherical sensor element is connected to the substrate 9 via lead wires 6a and 6b shown in FIG. 8 and the like. The protective cover 2 (here, the protective cover 2 shown in FIG. 1 and the like will be representatively described) surrounds the sensor elements 3 and 4 with a plurality of supports 13 extending in a direction in which the sensor elements 3 and 4 are arranged as viewed from the substrate 9, that is, in a diagonal direction with respect to the height direction (Z1-Z2 direction). This allows the sensor elements 3 and 4 to be appropriately protected from the outside and improves omnidirectionality in a 360-degree surrounding area. In this case, it is preferable to form the first sensor element 3 at a higher position than the second sensor element 4. Any of the structures of the first to fourth embodiments described above can be applied to the protective cover. In the above, the sensor device 1 has been described as detecting wind, but the fluid to be detected may be gas or liquid other than wind. [Industrial Applicability]

[0078] The present invention can adequately protect the sensor element from the outside and improve omnidirectionality in a 360-degree range, making it applicable to a variety of applications, such as air conditioning equipment, wind control systems, and analysis. [Explanation of symbols]

[0079] 1 Sensor device 2, 40, 50, 6, 70, 80 Protective cover 2a Surrounding area 2b Ceiling section 2c Fixed support part 2d First part 2e Second part 2f top surface 3 First sensor element 4 Second Sensor Element 6a, 6b, 8a, 8b lead wire 9 Substrate 9a Sensor section 9b Drive board 9c Connecting part 10 Flow rate detection resistor 11 Electrode cap 12 Insulating film 13, 41, 51, 61, 71, 72, 81, 82 pillars 13a Intersection 14 Posts 15, 43, 53 through holes 18 Bridge Circuit 19 First Series Circuit 20 Second Series Circuit 23 Differential Amplifier 24 Feedback Circuit 25 Ring section 26 Support 26a Claw part 26b Claw receiving part 27 Storage area 27a First storage compartment 27b Second storage area 27c Third storage compartment 28a Fitting protrusion 28b Fitting hole 29 Slot 30 Microcomputer 31 holes 32 Slit 33, 34 cases 34 cases 36, 37 Connector 38 Temperature compensation resistor 42 holes C center L1, L2 length dimensions T width dimension

Claims

1. A sensor device having a sensor element including a temperature sensitive resistor and a protective cover for protecting the sensor element, The sensor element has a shape that extends long in one direction, the protective cover surrounds the sensor element with a plurality of support columns extending in a direction oblique to a longitudinal direction of the sensor element, A plurality of the pillars intersect in a lattice pattern, An intersection portion where the plurality of pillars intersect and the sensor element overlap at one point in a side view. A sensor device comprising:

2. 2. The sensor device according to claim 1, wherein an intersection of the plurality of support columns is offset from the center of the sensor element in a side view for all angles in the circumferential direction.

3. 3. The sensor device according to claim 1, wherein the width of the support is shorter than the length of the sensor element in the longitudinal direction.

4. 4. The sensor device according to claim 1, wherein a length dimension from an outer side to an inner side of the support is longer than a width of the support.

5. 5. The sensor device according to claim 1, wherein the support pillar is formed to have a protruding cross-sectional shape whose width dimension gradually decreases from the inside to the outside.

6. 6. The sensor device according to claim 1, wherein the protective cover includes a storage portion at a lower end of the support column for storing a substrate supporting the sensor element.

7. A sensor device having a sensor element including a temperature sensitive resistor and a protective cover for protecting the sensor element, The sensor element is supported by a substrate; The temperature sensitive resistor is formed over the entire periphery of the sensor element, the protective cover surrounds the sensor element with a plurality of supports extending in a diagonal direction with respect to a direction in which the sensor element is disposed as viewed from the substrate, A plurality of the pillars intersect in a lattice pattern, A sensor device characterized in that an intersection portion where a plurality of the pillars intersect and the sensor element overlap at one point in a side view.

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