JP2019078736A - Rotation sensing device - Google Patents

Abstract

To provide a rotation sensing device capable of detecting positions of needles in more detail using a simple configuration.SOLUTION: A rotation sensing device 10 of the present invention comprises: a light-emitting element 11 for irradiating a dial plate 62B behind an indicator needle 62S with light; a photosensitive element 12 for detecting reflected light from the dial plate 62B; a control substrate 15 configured to perform position detection measurement; and a shield plate 13 made of a material that can be switched between a transmissive state for transmitting light and a non-transmissive state for blocking light, and disposed between the indicator needle 62S and the light-emitting element 11/photosensitive element 12. The shield plate 13 is divided into four segments 13S along a rotational direction of the indicator needle 62S, and the light-emitting element 11 and the photosensitive element 12 are disposed at positions that do not overlap with inter-segment borders. The control substrate 15 switches the segments 13S to the transmissive state or non-transmissive state to produce a plurality of types of transmission patterns, and performs position detection measurement in each transmission pattern.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotation detection device attached to a flow meter to detect the position of a needle that rotates according to the flow rate of fluid.

  In the rotation detection device of Patent Document 1, light is emitted from the light emitting element toward the dial on the back side of the hand, and the reflected light from the dial is detected by the light receiving element.

European Patent Publication No. 547879 (FIG 1, 2)

  In the rotation detection device of Patent Document 1, it is only known whether or not the needle is present at the point to which light is irradiated, so when light is irradiated to one location, the position of the needle that has deviated from the irradiation point Was difficult to detect. Here, if the light irradiation point is moved or the image is recognized, the detailed position of the needle can be detected, but another problem arises that the apparatus becomes complicated.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rotation detection device capable of detecting the position of a needle in more detail than in the prior art with a simple configuration.

  The invention according to claim 1 made to achieve the above object is a rotation detection device attached to a flow meter to detect the position of a needle rotating according to the flow rate of fluid, which is disposed on the back side of the needle A light emitting element for emitting light toward the dial face, a light receiving element for detecting reflected light from the dial face, and the light emitting element to emit light to detect the position of the needle Measurement unit for performing position detection measurement, and a material switchable between a transmission state for transmitting light and a non-transmission state for not transmitting light, and between the light emitting element and the light receiving element and the needle And a shielding plate disposed, wherein the shielding plate is divided into three or more segments in the rotational direction of the needle, and the light emitting element and the light receiving element do not overlap the boundaries between the segments. The measuring unit is arranged The segments are set in the transmission state or the non-transmission state so that two or more of the segments continuous in the rotational direction of the stylus are in the transmission state or the non-transmission state to form a plurality of types of transmission patterns It is a rotation detection device which performs the position detection measurement in each of the plurality of types of transmission patterns.

  In the invention of claim 2, the number of the segments is 2n (n is a natural number of 2 or more), and the measuring unit is configured to transmit the n segments continuous in the rotational direction of the needle in the transmission state The transmission pattern in which the remaining n pieces of the segments are in the non-transmissive state is formed in n types so that boundaries of the segments in the transmissive state and the segments in the non-transmissive state are not the same. Rotation detection device.

  The invention of claim 3 is the rotation detection device according to claim 2, wherein the number of segments is four.

  The invention according to claim 4 is the rotation detecting device according to any one of claims 1 to 3, wherein the plurality of segments are formed by dividing the shielding plate equally in the rotational direction of the needle. is there.

  In the invention of claim 5, when the fluid having the maximum flow rate that can be measured by the flow meter flows, the measurement unit makes the interval shorter than the time obtained by dividing the rotation period of the needle by the total number of the plurality of segments. The rotation detection device according to claim 4, wherein position detection measurement is performed.

  In the invention according to claim 6, the rotation detecting device according to any one of claims 1 to 5, wherein the light emitting element and the light receiving element are disposed apart by 180 degrees in the rotational direction of the needle. It is.

  The invention according to claim 7 is the rotation detection device according to any one of claims 1 to 6, comprising a light diffusion plate disposed between the light emitting element and the light receiving element and the needle. is there.

[Invention of Claim 1]
In the present invention, the light from the light emitting element is irradiated to the dial through the light shielding plate, and the reflected light from the dial is detected by the light receiving element to perform position detection measurement for detecting the position of the hand. It will be. The light shielding plate is made of a material that can be switched between a transmitting state in which light is transmitted and a non-transmitting state in which light is not transmitted, and is divided into three or more segments in the rotational direction of the needle. In addition, the light emitting element and the light receiving element are disposed at positions not overlapping the boundaries between the segments. The position detection measurement is performed on a plurality of types of transmission patterns formed by setting the segments in the transmission state or the non-transmission state. Therefore, when the needle overlaps with the segment in the transmission state, the amount of light detected by the light receiving element decreases, and it can be understood that the needle is present in the range overlapping with the segment. Here, when the needle overlaps with the edge of the segment, the needle overlaps with the boundary with the segment adjacent to the segment in the clockwise direction with respect to the segment or with the segment adjacent with the counterclockwise direction with respect to the segment. It becomes difficult to determine whether the needle is overlapping the boundary of However, in the present invention, since the plurality of transmission patterns are formed such that two or more continuous segments in the rotational direction of the needle are both in the transmission state or the non-transmission state, the needle overlaps with any boundary. It is possible to determine the presence or absence. As described above, according to the present invention, it is possible to detect the position of the needle in more detail than in the prior art by adopting a simple configuration.

[Inventions of claim 2 and 3]
According to the present invention, it is possible to reduce the number of position detection measurements to half the number of segments. In particular, as in the invention of claim 3, if the number of segments is four, it is possible to make the number of position detection measurements twice.

[Invention of Claim 4]
In the present invention, since the amount of light transmitted through the shielding plate is proportional to the number of segments in the transmission state, the control of the amount of light irradiated to the dial becomes easy.

[Invention of Claim 5]
In the present invention, since the range in which the needle can rotate between the previous position detection measurement and the current position detection measurement falls within the range of one segment, when the needle is rotated across the segment boundary, It is possible to determine whether the rotation direction is clockwise or counterclockwise. That is, according to the present invention, not only the position of the needle but also the rotational direction of the needle can be detected.

[Invention of Claim 6]
In the present invention, the light reflected from the dial is easily detected by the light receiving element.

[Invention of Claim 7]
According to the present invention, it is possible to stably irradiate the dial with the light from the light emitting element.

A perspective view of a water meter to which a rotation detection device is attached Diagram for explaining the arrangement of the display unit (A) A sectional view showing the internal structure of the rotation detection device, (B) a plan view showing the arrangement of the first support portion and the shielding plate Block diagram showing the electrical configuration of the rotation detection device (A) A diagram schematically showing the first transmission pattern of the shielding plate, (B) a diagram schematically showing the second transmission pattern A table showing the relationship between the position of the needle and the appearance of the needle in each transmission pattern The figure which shows typically the permeation | transmission pattern of the shielding board in the rotation detection apparatus which concerns on other embodiment. The figure which shows typically the permeation | transmission pattern of the shielding board in the rotation detection apparatus which concerns on other embodiment. The figure which shows typically the permeation | transmission pattern of the shielding board in the rotation detection apparatus which concerns on other embodiment.

  The water meter 50 as a flow meter with which the rotation detection apparatus 10 of this embodiment is attached is shown by FIG. The water meter 50 includes an inlet 51A and an outlet 51B at the lower part of the body 51. A display unit 60 is provided at the top of the body 51. The display unit 60 is a display board on which the cumulative use amount of the water supply is displayed, and is covered by the glass plate 52. The rotation detection device 10 is attached to the water meter 50 so as to overlap the display unit 60 from above.

  As shown in FIG. 2, the display unit 60 includes an integration counter 61, a 1 liter instructing unit 62, a 10 liter instructing unit 63, and a water flow pilot 64. The integration counter 61 displays the integrated usage of the water supply. The 1 liter instructing unit 62 includes a circular dial 62B in which the numbers 0 to 9 are written in the clockwise direction, and a hand 62S having a rotation axis 62J passing through the center of the dial 62B. Make a turn with 10 liters of water flow. The 10 liter instructing unit 63 includes a circular dial 63B in which the numbers 0 to 9 are written in the clockwise direction, and a needle 63S having a rotation axis 63J passing through the center of the dial 63B. Make one turn with 100 liters of water flow. The water flow pilot 64 has a rotation axis 64J perpendicular to the display unit 60, and rotates according to the water flow. When water flows from the inlet 51A of the water meter 50 to the outlet 51B (see FIG. 1), the water flow pilot 64 rotates clockwise.

  As shown in FIG. 3A, the rotation detection device 10 is disposed opposite to the 1 liter indicator 62, and emits light 11 for emitting light toward the dial 62B of the 1 liter indicator 62; And a light receiving element 12 for detecting the reflected light from the dial 62B. The light emitting element 11 and the light receiving element 12 are arranged offset by 180 degrees in the circumferential direction of the dial 62B (that is, the rotation direction of the hand 62S), and the distance between the light emitting element 11 and the dial 62B is the light receiving element 12 and the dial It is almost the same as the distance to 62B.

  The rotation detection device 10 is provided with a shielding plate 13 disposed between the light emitting element 11 and the light receiving element 12 and the needle 62S of the 1 liter instructing unit 62. The shielding plate 13 is made of, for example, liquid crystal, and changes between a transmitting state in which light is transmitted and a non-transmitting state in which light is not transmitted.

  Specifically, as shown in FIG. 3B, the shielding plate 13 is formed in a circular shape having a diameter larger than that of the dial 62B, and is disposed concentric with the dial 62B. The shielding plate 13 is divided into a plurality of segments 13S in the rotational direction of the needle 62S, and each segment 13S changes between the transmission state and the non-transmission state. In the present embodiment, the shielding plate 13 is equally divided into four segments 13S.

  Here, when the four segments 13S are appropriately referred to as the first segment 13A, the second segment 13B, the third segment 13C, and the fourth segment 13D in the order of arranging in the clockwise direction, the first segment 13A , The center of the circumferential direction overlaps the index "0" of the dial 62B. In the second segment 13B, the center in the circumferential direction overlaps the middle of the indices of "2" and "3" of the dial 62B. The center of the third segment 13C in the circumferential direction overlaps the index "5" of the dial 62B. The fourth segment 13D has a circumferential center that overlaps the middle of the "7" and "8" indexes of the dial 62B. The arrangement of the segments 13S is not limited to that described above. For example, the first segment 13A overlaps the range of 0 to 2.5 of the index of the dial 62B, and the second segment 13B is an index of 2. of the index. The third segment 13C may overlap with the range of 5 to 5, the third segment 13C may overlap with the range of 5 to 7.5 of the index, and the fourth segment 13D may overlap with the range of 7.5 to 0 of the index.

  As shown in FIG. 3A, the rotation detection device 10 is provided with the light diffusion plate 14 disposed between the light emitting element 11 and the light receiving element 12 and the needle 62S of the 1-litre indication unit 62. . The light diffusion plate 14 is made of a transparent plate material whose surface is roughened, and alleviates unevenness of light emitted from the light emitting element 11. In the present embodiment, the light diffusion plate 14 is disposed on the side opposite to the light emitting element 11 and the light receiving element 12 with respect to the shielding plate 13. The light diffusion plate 14 is, similarly to the shield plate 13, formed in a circular shape having a diameter larger than that of the dial 62B.

  As shown in FIG. 4, the rotation detection device 10 includes a control substrate 15 that controls the state of each segment 13 </ b> S in the shielding plate 13. The control substrate 15 is also connected to the light emitting element 11 and the light receiving element 12, transmits a control signal for irradiating the light emitting element 11 with light, and receives a detection signal from the light receiving element 12. Then, the control substrate 15 controls the light emitting element 11 and the shielding plate 13 (a plurality of segments 13S) to execute position detection measurement for detecting the position of the needle 62S of the 1 liter instructing unit 62. The result of the position measurement is transmitted to the outside via the transceiver 16.

  The control board 15 performs background measurement prior to position detection measurement. In the background measurement, the amount of light detected by the light receiving element 12 is measured without irradiating the light emitting element 11 with light. The background measurement may be performed every measurement cycle T1, or may be performed every time the position detection measurement is performed a predetermined number of times (for example, 100 times). The measurement of the background measurement is subtracted from the measurement of the position detection measurement as noise.

  The control substrate 15 controls the state of the plurality of segments 13S to form a plurality of transmission patterns on the shielding plate 13, and performs position detection measurement in each transmission pattern. The transmission pattern is formed such that two or more continuous segments 13S continuous in the rotational direction of the needle 62S are in the transmission state or the non-transmission state.

  In the present embodiment, the transmission patterns formed by the control substrate 15 are two as shown in FIG. 5 (A) and FIG. 5 (B). In the first transmission pattern shown in FIG. 5A, the second segment 13B and the third segment 13C are in the transmission state, and the first segment 13A and the fourth segment D are in the transmission non-transmission state. In the second transmission pattern shown in FIG. 5B, the first segment 13A and the second segment 13B are in the transmission state, and the third segment 13C and the fourth segment 13D are in the transmission non-transmission state. In FIG. 5A and FIG. 5B, the non-transmissive segment 13S is hatched.

  FIG. 6 shows the relationship between the position of the needle 62S and the appearance of the needle 62S in each transmission pattern. The "position of the hand" in the figure corresponds to the position of the index on the dial 62B. That is, when the position of the hand 62S is 2.5, as shown in FIG. 3B, the hand 62S is disposed in the middle of the indicators of "2" and "3" of the dial 62B. Means

  Further, “the appearance of the needle” in FIG. 6 corresponds to the amount of light detected by the light receiving element 12. That is, when the entire needle 62S overlaps with the segment 13S in the transmission state, the amount of light detected by the light receiving element 12 is reduced by the needle 62S. If the entire needle 62S overlaps the non-transmissive segment 13S, the amount of light detected is not reduced by the needle 62S. If the needle 62S overlaps the boundary between the transmissive segment 13S and the non-transmissive segment 13S, the amount of light detected is slightly reduced by a portion of the needle 62S. In the figure, when the amount of light detected by the light receiving element 12 is not decreased, it is indicated by “0” because the needle 62S is not detected, and when the amount of light detected is slightly decreased, the needle 62S Is partially represented as "0.5", and when the amount of light to be detected decreases, the entire needle 62S is represented as "1".

  As shown in FIG. 6, when the position of the needle 62S is in the range of 0 to 1.25 or 8.75 to 0, the needle 62S is not detected in the first transmission pattern and the needle in the second transmission pattern 62S is detected. When the position of the needle 62S is in the range of 1.25 to 3.75, the entire needle 62S is detected in both the first transmission pattern and the second transmission pattern. When the position of the needle 62S is in the range of 3.75 to 6.25, the entire needle 62S is detected in the first transmission pattern, and the needle 62S is not detected in the second transmission pattern. When the position of the needle 62S is in the range of 6.25 to 8.75, the needle 62S is not detected in both the first transmission pattern and the second transmission pattern. From the above, the detection / non-detection of the needle 62S in each of the first transmission pattern and the second transmission pattern makes it possible to know in which range of the dial 62B the needle 62S is present.

  Here, for example, when a part of the needle 62S is detected in the first transmission pattern, the needle 62S is present at the boundary between the first segment 13A and the second segment 13B only from the detection result in the transmission pattern. Although it becomes unclear whether it exists or at the boundary between the third segment 13C and the fourth segment 13D, the needle 62S exists at any boundary by combining it with the detection result in the second transmission pattern. You can identify the Similarly, even when part of the needle 62S is detected in the second transmission pattern, the position of the needle 62S can be identified by combining it with the detection result in the first transmission pattern.

  In the rotation detection device 10 according to the present embodiment, position detection measurement is performed for both the first transmission pattern and the second transmission pattern at a constant measurement cycle T1. Here, the maximum flow rate of water flowing through the water meter 50 is predetermined. The measurement cycle T1 is equal to or less than a quarter of the shortest circulation time T2 required for the hand 62S to make one revolution of the dial 62B when water at the maximum flow rate flows through the water meter 50. Therefore, the range in which the needle 62S can rotate during the measurement cycle T1 falls within the range of one segment 13S, and when the needle 62S rotates across the boundary of the segment 13S, the rotation direction of the needle 62S is opposite to the clockwise direction. It is possible to determine which is clockwise. That is, according to the rotation detection device 10 of the present embodiment, it is possible to detect not only the position of the needle 62S but also the rotational direction of the needle 62S.

  As described above, the rotation detection device 10 according to this embodiment forms the first transmission pattern and the second transmission pattern by setting the segment 13S of the shielding plate 13 in the transmission state or the non-transmission state, and positions the respective transmission patterns. By performing the detection measurement, the position of the needle 62S is detected. As described above, according to the rotation detection device 10, it is possible to detect the position of the needle 62S in more detail than in the past by adopting a simple configuration.

  Moreover, in the rotation detection device 10, since the shielding plate 13 is divided into four segments 13S, the position of the needle 62S can be detected only by forming two transmission patterns, and the number of position detection measurements can be increased. It can be reduced.

  Here, it is possible to detect the position of the needle 62S, for example, by forming transmission patterns in which only one segment 13S is in the transmission state and the remaining segments 13S are in the non-transmission state. However, when the number of segments 13S is 2n (n is a natural number of 2 or more), n types of transmission patterns are sufficient, as described below. That is, when the entire needle 62S overlaps with the segment 13S, if the segment 13S can be identified, the position of the needle 62S can be known. Therefore, the n segments 13S continuous in the rotational direction of the needle 62S are in the transmission state, and the remaining n segments 13S are in the nontransmission state, and the shielding plate 13S has one light transmitting region and one light transmitting region. If one transmission pattern is formed and then the light transmission region and the non-transmission region of the shielding plate 13 are shifted by one segment 13S to form n types of transmission patterns, the segments 13S in the n types of transmission patterns are formed. It is possible to make the transmission / non-transmission state change of all the segments 13S different. In the example of FIGS. 5A and 5B, the first segment 13A is in the non-transmissive state in the first transmission pattern and in the transmissive state in the second transmission pattern, and the second segment 13B is the first segment. The third segment 13C is in the transmission state in both the transmission pattern and the second transmission pattern, the third segment 13C is in the transmission state in the first transmission pattern, and is in the non-transmission state in the second transmission pattern, and the fourth segment 13D is the first Both the transmission pattern and the second transmission pattern are in the non-transmission state. Therefore, it is possible to determine which segment 13S the needle 62S overlaps with n types of transmission patterns. When the needle 62S overlaps with the boundary between the segments 13S, if the boundary can be identified, the position of the needle 62S is known, but also in this case, it is possible to distinguish by n types of transmission patterns. It becomes. The 2n segments 13S do not have to divide the shielding plate 13 equally. In this case, the detected light amount may be corrected according to the difference in the area of the segment 13S.

  Further, in the rotation detection device 10, since the plurality of segments 13S divides the shielding plate 13 equally, the amount of light transmitted through the shielding plate 13 is proportional to the number of the segments 13S in the transmission state, and the character Control of the amount of light emitted to the board 62B is facilitated.

  Furthermore, in the rotation detection device 10, the shielding plate 13 is divided equally into four segments 13S, and when the water having a maximum flow rate flows to the water meter 50, the hand 62S makes one round of the dial 62B in the measurement cycle T1. Since it is equal to or less than a quarter of the shortest rounding time T2 required for the above, it is possible to detect not only the position of the hand 62S but also the rotational direction.

  In the present embodiment, the needle 62S corresponds to the "needle" of the present invention, and the control board 15 corresponds to the "measurement unit" of the present invention.

[Other embodiments]
The present invention is not limited to the above-described embodiment, and, for example, the embodiments described below are also included in the technical scope of the present invention, and various other variations are possible without departing from the scope of the invention. It can be changed and implemented.

  (1) In the above embodiment, the light diffusion plate 14 may be disposed on the same side as the light emitting element 11 and the light receiving element 12 with respect to the shielding plate 13. Further, in the above embodiment, the light diffusion plate 14 may not be provided.

  (2) In the above embodiment, the rotation detection device 10 is attached to the water meter 50. However, the rotation detection device 10 may be attached to a flow meter having a needle that rotates according to the flow rate. It is not something to be done.

  (3) In the above embodiment, four segments are formed by changing one of the segments 13S which forms a transmission pattern and changes the non-transmission state by making one segment 13S into a non-transmission state and making the remaining segments 13S into a transmission state. A transmission pattern may be formed. In this case, position detection measurement is performed for all transmission patterns at each measurement cycle T1.

  (4) In the above embodiment, the shielding plate 13 may be equally divided into three segments 13S, or may be equally divided into five or more segments. In the case of division into three segments 13S, for example, the position of the needle 62S can be detected by forming three transmission patterns shown in FIG. 7A to FIG. 7C. Further, in the case of division into five segments 13S, for example, the position of the needle 62S can be detected by forming the three transmission patterns shown in FIGS. 8A to 8C. . In any case, if the measurement cycle T1 is set equal to or less than the time obtained by dividing the shortest circulation time T2 by the number of segments, the direction of rotation of the hand 62S can be determined.

  (5) In the above embodiment, the shielding plate 13 may not be divided equally, and the plurality of segments 13S may have different sizes. Even in this case, the position detection measurement is performed with the two types of transmission patterns of the first and second transmission patterns shown in FIGS. 9A and 9B, whereby the position of the needle 62S is determined. It can be detected. If the plurality of segments 13S have different sizes, a difference occurs in the area of the segment 13S in the transmission state among the plurality of transmission patterns. Therefore, if the difference in the area is taken into consideration, the detected light amount is corrected. Good. Also, if the measurement cycle T1 is set in accordance with the shortest segment 13S in the circumferential direction, it is also possible to determine the rotational direction of the needle 62S.

DESCRIPTION OF SYMBOLS 10 Rotation detection apparatus 11 Light emitting element 12 Light receiving element 13 Shielding board 15 Control board (measurement part)
50 water meter (flow meter)
60 indicator 62 1 liter indicator 62B dial 62S hands

Claims (7)

A rotation detection device attached to a flow meter for detecting the position of a needle that rotates according to the flow rate of fluid,
A light emitting element for emitting light toward a dial disposed on the back side of the hand;
A light receiving element for detecting reflected light from the dial;
A measurement unit that performs position detection measurement for detecting the position of the needle by irradiating the light emitting element with light;
It is made of a material switchable between a transmitting state for transmitting light and a non-transmitting state for transmitting light, and has a shielding plate disposed between the light emitting element and the light receiving element and the needle,
The shielding plate is divided into three or more segments in the rotational direction of the needle,
The light emitting element and the light receiving element are disposed at positions not overlapping the boundaries between the segments,
The measurement unit sets the segments in the transmission state or the non-transmission state so that two or more of the segments continuous in the rotational direction of the needle are in the transmission state or the non-transmission state. A rotation detection device which forms a transmission pattern and performs the position detection measurement in each of the plurality of types of transmission patterns. The number of segments is 2n (n is a natural number of 2 or more),
The measurement unit is configured to transmit a transmission pattern in which n consecutive segments in the rotational direction of the needle are in the transmission state and the remaining n segments are in the non-transmission state, The rotation detection device according to claim 1, wherein n types are formed so that boundaries of the segments in the non-transmissive state are not the same.   The rotation detection device according to claim 2, wherein the number of segments is four.   The rotation detection device according to any one of claims 1 to 3, wherein the plurality of segments are formed by equally dividing the shield plate in the rotational direction of the needle.   The measurement unit performs the position detection measurement at an interval shorter than a time obtained by dividing the rotation period of the needle when the fluid having the maximum flow rate measurable by the flow meter flows by the total number of the plurality of segments. The rotation detection device according to claim 4.   The rotation detecting device according to any one of claims 1 to 5, wherein the light emitting element and the light receiving element are disposed apart by 180 degrees in the rotational direction of the needle.   The rotation detection device according to any one of claims 1 to 6, further comprising a light diffusion plate disposed between the light emitting element and the light receiving element and the needle.

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