JP2014049043A - Construction work locking/unlocking detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction work locking/unlocking detection device capable of increasing the workability of construction work while preventing the manufacturing cost to increase.SOLUTION: A magnetic detection unit 3 includes: two magnetoresistive elements 30A and 30B forming a voltage-dividing circuit; and a bias magnetic 31 that applies a bias magnetic field to the magnetoresistive elements 30A and 30B. A bias voltage Vcc is applied to the voltage-dividing circuit, the magnetic detection unit 3 outputs a voltage which is the bias voltage Vcc divided by the voltage-dividing circuit to a determination section 4 as a detection signal Vout. Therefore, same as a Hall element, bidirectional magnetic fields can be detected by using the magnetoresistive elements 30A and 30B which is inexpensive than the Hall element. Thus, the workability of construction work is increased while preventing the manufacturing cost to increase.

Description

  The present invention relates to a locking / unlocking detection device for joinery that detects locking / unlocking of a lock that locks a fitting provided in a doorway or a window of a building.

  For example, Patent Literature 1 discloses a door tightness detection device that detects each state of locking and unlocking of a crescent lock provided on a fitting (sliding door) that opens and closes a window. In this conventional example, a permanent magnet is attached to an operation piece of a crescent lock provided on one side of a retractable window frame, and a proximity sensor is incorporated in a wireless transmitter provided on the other window frame. A reed switch is used for the proximity sensor. In the locked state of the crescent lock, the reed switch is turned on by the magnetic field of the permanent magnet attached to the operation piece, and in the unlocked state, the reed switch is separated to release the permanent magnet attached to the operation piece. The switch turns off. Then, the lock / unlock state of the crescent lock detected by turning on / off the reed switch is transmitted from the wireless transmitter as a wireless signal.

JP-A-6-309572

  By the way, the reed switch can be switched on and off only by the strength of the magnetic field, regardless of the direction of the magnetic flux interlinking, but it has the disadvantage that it is relatively large due to its mechanical contact structure. Yes.

  In contrast, a magnetic sensor using a Hall element, a magnetoresistive element, or the like can be easily downsized as compared to a reed switch. However, the Hall element can detect the magnetic field in the direction reversed by 180 degrees, but the magnetoresistive element can detect only the magnetic field in the same direction as the current direction. However, the Hall element has a lower sensitivity than the magnetoresistive element and requires a permanent magnet having a strong magnetic force, so that the size of the permanent magnet increases, so that the mounting restrictions are increased and the cost of the permanent magnet is increased. There is a drawback. In addition, magnetic sensors using magnetoresistive elements are regulated in terms of the arrangement of the permanent magnet relative to the magnetic field direction (current direction). End up. Therefore, since it is necessary to align the direction of the magnetic field of the permanent magnet and the direction of the magnetic sensor during construction, there is a problem that the construction work becomes complicated.

  This invention is made | formed in view of the said subject, and aims at improving the workability | operativity at the time of construction, suppressing the raise of manufacturing cost.

  The locking / unlocking detection device for joinery of the present invention is a locking / unlocking detection device for fittings that detects the locking / unlocking of the lock that locks the fitting provided in the entrance / exit of the building, and is displaced between the locking position and the unlocking position. A permanent magnet attached to the operation piece of the lock, and a magnetic detector attached to the joinery to detect a magnetic field, the magnetic detector comprising a plurality of magnetoresistive elements forming a voltage dividing circuit, A bias magnet for applying a bias magnetic field to the magnetoresistive element, a bias voltage is applied to the voltage dividing circuit, and a voltage obtained by dividing the bias voltage by the voltage dividing circuit is output as a detection signal. And

  In this joinery unlocking detection apparatus, the magnetic detection unit has a bridge circuit in which the two voltage dividing circuits are connected in parallel, and outputs a potential difference between the voltage dividing points of the voltage dividing circuit as a detection signal. Is preferred.

  The joinery locking / unlocking detection device includes a determination unit that determines a displacement position of the operation piece from a detection signal of the magnetic detection unit, and the determination unit has a resistance value of the magnetoresistive element that forms the voltage dividing circuit. The change is detected individually, and the displacement position is determined from the detection signal by determining the influence of the temperature in the change of the detection signal and the influence of the magnetic field due to the displacement position according to the direction of the change in the resistance value. Is preferred.

  The joinery locking / unlocking detection device includes a determination unit that determines a displacement position of the operation piece from a detection signal of the magnetic detection unit, and the determination unit has a resistance value of the magnetoresistive element that forms the voltage dividing circuit. The change is detected individually, the influence of the temperature in the detection signal is estimated according to the direction of the change in the resistance value, the detection signal is corrected so as to reduce the influence of the temperature, and the corrected detection signal It is preferable to determine the displacement position from

  The locking / unlocking detection device for joinery of the present invention can detect a bidirectional magnetic field in the same manner as a Hall element using a magnetoresistive element that is less expensive than a Hall element, so it can be constructed while suppressing an increase in manufacturing cost. There is an effect that the workability at the time can be improved.

It is a block diagram of the magnetic detection part in Embodiment 1 of the locking / unlocking detection apparatus for joinery concerning this invention. It is the perspective view which abbreviate | omitted a part same as the above. It is a circuit block diagram same as the above. It is the perspective view which abbreviate | omitted partially which shows Embodiment 2 of the locking / unlocking detection apparatus for joinery which concerns on this invention. The magnet block same as the above is shown, (a) is a perspective view, (b) is sectional drawing. It is a block diagram of the magnetic detection part in Embodiment 3 of the locking / unlocking detection apparatus for joinery which concerns on this invention.

  Hereinafter, referring to the drawings, an embodiment in which the technical idea of the present invention is applied to a locking / unlocking detection device for fittings that detects each state of locking and unlocking of a crescent lock provided on a fitting (sliding door) that opens and closes a window. And will be described in detail.

  As shown in FIG. 2, the crescent lock 100 includes a crescent lock body 101 fixed to one window frame 110 of two sliding-type window frames 110 and 111, and a crescent receptacle fixed to the other window frame 111. It is composed of 102. The crescent lock body 101 includes a rectangular parallelepiped base 103, a half-moon-shaped crescent portion 104 provided so as to be rotatable with respect to the base 103, and a rectangular shape whose one end is coupled to the crescent portion 104 and protrudes parallel to the base 103. And a box-shaped operation piece 105. The crescent portion 104 and the operation piece 105 are pivotally supported on the base 103 so as to be rotatable about the center of the crescent portion 104 as a fulcrum. Then, by rotating the crescent portion 104 with the operation piece 105, when the operation piece 105 is positioned on the crescent portion 104, the crescent portion 104 is engaged with the crescent receiver 102 and the crescent lock 100 is locked. It becomes. On the other hand, when the operation piece 105 is positioned below the crescent portion 104, the engagement between the crescent portion 104 and the crescent receiver 102 is released, and the crescent lock 100 is unlocked. However, since such a crescent lock 100 is conventionally well-known, illustration and description of the detailed structure of the crescent lock body 101 are omitted. In the following, as shown in FIG. 2, the position of the operation piece 105 when the crescent lock 100 is in the locked state (position above the crescent portion 104) is referred to as “locking position”, and when the crescent lock 100 is in the unlocked state. The position of the operation piece 105 (position below the crescent portion 104) will be referred to as “unlock position”.

(Embodiment 1)
The lock / unlock detection device for joinery (hereinafter, abbreviated as “detection device”) according to the present embodiment is provided on the indoor side surface of the permanent magnet 1 attached to the operation piece 105 and the window glass 112 supported by the other window frame 111. And a detector main body 2 to be attached.

  The permanent magnet 1 is attached to a position overlapping the rotation shaft on the side surface of the operation piece 105 using a double-sided tape or the like, and one end side in the vertical direction in FIG. 2 is an N-pole magnetic pole and the other end side is an S-pole magnetic pole. It has become. However, when the operation piece 105 is formed in a box shape that opens to one surface, it is preferable that the permanent magnet 1 is disposed in the internal space of the operation piece 105. In other words, the permanent magnet 1 is not exposed on the surface of the operation piece 105 by being housed in the operation piece 105, and the human hand (finger) is not touched when the operation piece 105 is operated. Thus, the displacement of the permanent magnet 1 can be prevented.

  As shown in FIGS. 2 and 3, the detection device main body 2 includes a magnetic detection unit 3, a determination unit 4, a control unit 5, a wireless communication unit 6, a power supply battery 7, a case 8 for storing them, and the like. Yes. As shown in FIG. 1, the magnetic detection unit 3 includes two magnetoresistive elements 30A and 30B that form a voltage dividing circuit, and a bias magnet 31 that applies a bias magnetic field to the magnetoresistive elements 30A and 30B. A bias voltage Vcc is applied to the voltage dividing circuit, and the magnetic detection unit 3 outputs a voltage obtained by dividing the bias voltage Vcc by the voltage dividing circuit to the determination unit 4 as a detection signal Vout. The detailed configuration and operation of the magnetic detection unit 3 will be described later.

  Here, a pair of magnetic derivatives 9 are provided in the vicinity of the magnetic detection unit 3. The magnetic derivative 9 is formed in a thin plate shape with a magnetic material having magnetic anisotropy, for example, an electromagnetic steel plate, ferrite, permalloy, amorphous magnetic material or the like. In the present embodiment, the magnetic derivative 9 is formed in a polygonal (hexagonal) shape combining a rectangle and a trapezoid with one side of the rectangle as the bottom. The pair of magnetic derivatives 9 are arranged so that the upper base of the trapezoid faces the magnetic detection unit 3 and faces the magnetic detection unit 3 therebetween.

  The determination unit 4 determines the displacement position (locking position and unlocking position) of the operation piece 105 by performing signal processing on the detection signal Vout of the magnetic detection unit 3. For example, the wireless communication unit 6 performs wireless communication using radio waves as a medium with a security device (not shown) installed in the house. The control unit 5 transmits monitoring information (locked / unlocked state of the crescent lock 100) corresponding to the determination result of the determination unit 4 to the security device by a wireless signal transmitted from the wireless communication unit 6. Then, the security device acquires the detection result of the detection device, that is, the locked / unlocked state of the crescent lock 100 by receiving the radio signal, and notifies (displays) the result by sound or light. However, since such a security device and a security system including the security device and the detection device are well known in the art, detailed illustration of the configuration and description of the operation are omitted.

  The case 8 is made of a flat, rectangular parallelepiped synthetic resin molding, and is attached to the window glass 112 using a double-sided tape or the like. Further, the case 8 accommodates the magnetic detector 3 and the magnetic derivative 9 on one end side in the longitudinal direction (upper side in FIG. 2), and two batteries (button batteries) on the other end side in the longitudinal direction (lower side in FIG. 2). 7 is stored. The determination unit 4, the control unit 5, the wireless communication unit 6, and the like are mounted on a printed wiring board (not shown) and housed in the case 8. Here, FIG. 2 shows a state in which a part of the case 8 is removed and exposed to the outside, but actually, the magnetic detection unit 3, the magnetic derivative 9, and the battery 7 are not exposed to the outside.

  Next, the magnetic detection unit 3 that is the gist of the present invention will be described in more detail. As shown in FIG. 1, the bias magnet 31 is formed in a square thin plate shape, the left portion from the longitudinal center line X is magnetized to the N pole, and the right portion is magnetized to the S pole. . The magnetoresistive elements 30A and 30B are disposed on the bias magnet 31, and a bias magnetic field (bias magnetic flux φ0) parallel to the lateral center line Y and directed to the right is applied. However, in the magnetoresistive elements 30A and 30B, the magnetic detection directions (current flow directions) D1 and D2 have an inclination of π / 4 (45 degrees) with respect to the center lines X and Y in the vertical and horizontal directions. (See FIG. 1).

  Here, the magnetic flux φs of the permanent magnet 1 is linked downward along the longitudinal center line X with respect to the magnetic detection unit 3 when the displacement position of the operation piece 105 is the locking position. Therefore, the vector of the magnetic flux φw interlinked with the magnetoresistive elements 30A and 30B (hereinafter referred to as the magnetic flux vector) is a combined magnetic flux vector of the magnetic flux vector φ0 of the bias magnetic flux and the magnetic flux vector φs of the permanent magnet 1. When the angles formed by the combined magnetic flux vector φw and the magnetic detection directions D1 and D2 are θ1 and θ2, respectively, the resistance values R1 and R2 of the magnetoresistive elements 30A and 30B when the magnetic field of the permanent magnet 1 is applied are as follows: It is represented by the following formula 1.

[Formula 1]
Ri = Ri-0 × ρ (1-cos2θi) / 2 (i = 1, 2)
However, Ri-0 is a resistance value (initial resistance value) when the magnetic field of the permanent magnet 1 is not applied (when the magnetic flux vector φs of the permanent magnet 1 is zero), and ρ is a magnetic field change coefficient.

  Thus, when the magnetic flux vector φs of the permanent magnet 1 is linked downward as shown in FIG. 1, the angle formed by the combined magnetic flux vector φw and the magnetic flux vector φ0 of the bias magnetic flux is in the range of 0 to −π / 2. Become. Therefore, the resistance values R1 and R2 of the magnetoresistive elements 30A and 30B obtained from Equation 1 increase one resistance value R1, while the other resistance value R2 decreases, and the amount of change is the permanent magnet 1. Is proportional to the magnitude of the magnetic flux vector φs.

  When the magnetic flux vector φs of the permanent magnet 1 is linked upward, the angle formed by the combined magnetic flux vector φw and the magnetic flux vector φ0 of the bias magnetic flux is in the range of 0 to π / 2. Therefore, the resistance values R1 and R2 of the magnetoresistive elements 30A and 30B obtained from Equation 1 are such that one resistance value R1 decreases while the other resistance value R2 increases, and the amount of change thereof is the permanent magnet 1. Is proportional to the magnitude of the magnetic flux vector φs. That is, the signal voltage of the detection signal Vout of the magnetic detection unit 3 is relatively low when the displacement position of the operation piece 105 is the locked position, and is relatively high when the displacement position of the operation piece 105 is the unlocked position. Become.

  Next, the operation of the detection apparatus of this embodiment will be described. First, when the joinery (sliding door) is closed, the permanent magnet 1 attached to the operation piece 105 is close to the detection device body 2, so that the magnetic flux of the permanent magnet 1 is chained to the magnetic detection unit 3. The detection signal Vout at a predetermined level is output from the magnetic detection unit 3. On the other hand, when the joinery is opened, the distance between the permanent magnet 1 and the detection device main body 2 increases, so that the signal voltage of the detection signal Vout of the magnetic detection unit 3 is the initial resistance value of the magnetoresistive elements 30A and 30B. A divided value (referred to as a reference value) is obtained. Therefore, the determination unit 4 can determine that the joinery is open when the signal voltage of the detection signal Vout of the magnetic detection unit 3 is substantially equal to the reference value.

  Further, when the joinery is closed and the displacement position of the operation piece 105 is the locked position, the signal voltage of the detection signal Vout of the magnetic detection unit 3 decreases as described above. Therefore, the determination unit 4 compares the signal voltage of the detection signal Vout with a threshold value (locking threshold value) set lower than the reference value, and the signal voltage of the detection signal Vout falls below the locking threshold value. The displacement position of the operation piece 105 can be determined as the locking position.

  Furthermore, when the joinery is closed and the displacement position of the operation piece 105 is the unlocked position, the signal voltage of the detection signal Vout of the magnetic detection unit 3 increases as described above. Therefore, the determination unit 4 compares the signal voltage of the detection signal Vout with a threshold value (unlocking threshold value) set higher than the reference value, and the signal voltage of the detection signal Vout exceeds the unlocking threshold value. In this case, the displacement position of the operation piece 105 can be determined as the unlock position.

  By the way, when the permanent magnet 1 is attached in a direction different by 180 degrees with respect to the operation piece 105, the magnetic flux vector φs of the permanent magnet 1 is linked upward when the operation piece 105 is in the locked position, and the operation piece 105 is released. At the locked position, the magnetic flux vector φs of the permanent magnet 1 is linked downward. Therefore, although the relationship between the displacement position of the operation piece 105 and the detection signal Vout of the magnetic detection unit 3 is reversed, the determination unit 4 can detect the displacement position of the operation piece 105.

  Therefore, when the operator confirms the operation of the detection device main body 2 at the time of construction, and the displacement position of the operation piece 105 and the detection result of the detection device main body 2 are reversed, a tact switch (see FIG. What is necessary is just to switch the determination conditions of the determination part 4 by pushing operation (not shown). In this way, even if the permanent magnet 1 and the detection device main body 2 are attached in a direction reversed 180 degrees from the correct direction, the locking / unlocking of the operation piece 105 can be detected correctly.

  As described above, according to the present embodiment, a bidirectional magnetic field can be detected using the magnetoresistive elements 30A and 30B, which are less expensive than the Hall element, as in the Hall element. As a result, workability during construction can be improved while suppressing an increase in manufacturing cost.

  In the present embodiment, a pair of magnetic derivatives 9 are arranged at positions facing each other with the magnetic detection unit 3 interposed therebetween. For this reason, compared with the case where there is no magnetic derivative | guide_body 9, the magnetic flux linked with the magnetic detection part 3 can be increased (magnetic flux density can be enlarged). As a result, even if the permanent magnet 1 having a smaller dimension (weak magnetic field) than that of the conventional example is used, the detection sensitivity equivalent to that of the conventional example can be maintained. Further, the magnetic derivative 9 is formed in a shape in which the width dimension in the direction (left-right direction) intersecting the magnetic field detection direction (up-down direction in FIG. 2) increases as the distance from the magnetic detection unit 3 increases. Therefore, since the magnetic flux entered from the wide end of the magnetic derivative 9 can be linked to the magnetic detection unit 3 from the narrow end, the detection sensitivity of the magnetic detection unit 3 can be improved. When the magnetic derivative 9 is made of a magnetic material having magnetic anisotropy, the magnetic derivative 9 is arranged such that the direction of easy magnetization coincides with the magnetic field detection direction of the magnetic detection unit 3. The detection sensitivity of the unit 3 can be further improved.

(Embodiment 2)
As shown in FIG. 4, the detection device of the present embodiment includes a magnet block 10 and a detection device body 2. In addition, the same code | symbol is attached | subjected to the same component as Embodiment 1, and description is abbreviate | omitted.

  As shown in FIG. 5, the magnet block 10 is formed in a box shape with a material that does not shield magnetism (for example, synthetic resin), and a housing 11 that houses the permanent magnet 1 therein, and the housing 11 as an operation piece 105. A string body 12 to be connected and an attaching member 13 for attaching the casing 11 to the surface of the operation piece 105 are provided.

  The housing 11 is composed of a rectangular box-shaped body 11A whose one surface (lower surface in FIG. 5) is opened, and a rectangular plate-shaped cover 11B coupled to the body 11A so as to close the opening. Further, the housing 11 has an insertion hole 11C through which the string body 12 is inserted, penetrating in the left-right direction. The string body 12 includes a binding band for binding electric cables and the like. However, the string body 12 is not limited to a binding band, and may be an adhesive tape, a self-bonding tape, a heat shrinkable tube, or the like.

  The affixing member 13 is made of, for example, a conventionally known double-sided tape, and affixed to the bottom surface of the casing 11 (the lower surface in FIG. 5).

  Thus, after the other side of the affixing member 13 affixed to the housing 11 on one side is affixed to the side surface of the operation piece 105 (the surface facing the window glass 112), the string body 12 is attached to the operation piece 105. The magnet block 10 can be firmly attached to the operation piece 105 by being wound around and bound (see FIG. 4). However, it is desirable that the sticking member 13 is stuck on the operation piece 105 to temporarily fix the magnet block 10 and after confirming that the detection device main body 2 can detect normally, the string body 12 is bound and finally fixed.

  On the other hand, when the operation piece 105 is in the locked position, the detection device main body 2 has an indoor side of the window glass 112 so that the magnetic detection unit 3 faces the magnet block 10 attached to the operation piece 105 in close proximity. (See FIG. 4). However, the magnetic detection unit 3 in the present embodiment is arranged so that the magnetic field detection direction is in the short direction of the case 8 (left and right direction in FIG. 4), and the pair of magnetic derivatives 9 are also in the short direction of the case 8. It is arrange | positioned along the both sides of the magnetic detection part 3 along.

  Next, the operation of the detection apparatus of this embodiment will be described. First, when the displacement position of the operation piece 105 is the unlocked position, the distance between the permanent magnet 1 and the detection device main body 2 increases, so that the signal voltage of the detection signal Vout of the magnetic detection unit 3 substantially matches the reference value. Yes. On the other hand, when the displacement position of the operation piece 105 is the locked position as shown in FIG. 4, the magnetic flux vector φ0 of the bias magnetic flux and the combined magnetic flux vector φw of the magnetic flux vector φs of the permanent magnet 1 are linked to the magnetic detection unit 3. As a result, since the signal voltage of the detection signal Vout of the magnetic detection unit 3 increases (or decreases) from the reference value and exceeds the threshold value, the determination unit 4 determines the displacement position of the operation piece 105 as the lock position. be able to.

  Also in the present embodiment, the operator confirms the operation of the detection device main body 2 during construction, for example, when the signal voltage of the detection signal Vout decreases from the reference value when the displacement position of the operation piece 105 is the locking position. The determination condition of the determination unit 4 may be switched by pressing a tact switch (not shown) provided in the detection device body 2. In this way, as in the first embodiment, even when the permanent magnet 1 and the detection device main body 2 are mounted in a direction reversed 180 degrees from the correct direction, the locking / unlocking of the operation piece 105 can be detected correctly. .

(Embodiment 3)
The present embodiment is characterized in the configuration of the magnetic detection unit 3, and the basic configuration of the magnetic detection unit 3 and the configuration other than the magnetic detection unit 3 are the same as those in the first or second embodiment. Therefore, components common to the first or second embodiment are denoted by the same reference numerals, and illustration and description thereof are omitted.

  As shown in FIG. 6, the magnetic detector 3 has a bridge circuit in which a voltage dividing circuit of two magnetoresistive elements 30A and 30B and a voltage dividing circuit of two magnetoresistive elements 30C and 30D are connected in parallel. . However, in the magnetoresistive elements 30C and 30D, the magnetic detection directions (current flow directions) D3 and D4 have an inclination of π / 4 (45 degrees) with respect to the center lines X and Y in the vertical and horizontal directions. (See FIG. 6). Further, the magnetic detection unit 3 amplifies the potential difference between the voltage dividing points of the two voltage dividing circuits (between the connection point of the magnetoresistive elements 30A and 30B and the connection point of the magnetoresistive elements 30C and 30D) by the amplifier 32. The output is the detection signal Vout.

  Here, if the angles formed by the combined magnetic flux vector φw and the magnetic detection directions D3 and D4 of the magnetoresistive elements 30C and 30D are θ3 and θ4, respectively, the magnetoresistive elements 30C and 30C when the magnetic field of the permanent magnet 1 is applied. The resistance values R3 and R4 of 30D are expressed by Equation 1 described in the first embodiment.

  Thus, as shown in FIG. 6, when the magnetic flux vector φs of the permanent magnet 1 is linked downward, the angle formed by the combined magnetic flux vector φw and the magnetic flux vector φ0 of the bias magnetic flux is in the range of 0 to −π / 2. Become. Therefore, the resistance values R1 to R4 of the magnetoresistive elements 30A, 30B, 30C, and 30D obtained from Equation 1 increase the resistance values R1 and R3 of the two magnetoresistive elements 30A and 30C at the diagonal positions. On the other hand, the resistance values R2 and R4 of the other two magnetoresistive elements 30B and 30D that are also at the diagonal positions are decreased.

  When the magnetic flux vector φs of the permanent magnet 1 is linked upward, the angle formed by the combined magnetic flux vector φw and the magnetic flux vector φ0 of the bias magnetic flux is in the range of 0 to π / 2. Therefore, the resistance values R1 to R4 of the magnetoresistive elements 30A, 30B, 30C, and 30D obtained from the equation 1 decrease the resistance values R1 and R3 of the two magnetoresistive elements 30A and 30C at the diagonal positions. On the other hand, the resistance values R2 and R4 of the other two magnetoresistive elements 30B and 30D that are also at the diagonal positions increase. That is, as the displacement position of the operation piece 105 is reversed, the potential difference between the voltage dividing points of the two voltage dividing circuits is also inverted between the positive and negative, so that the determination unit 4 determines the signal voltage of the detection signal Vout of the magnetic detection unit 3. The displacement position of the operation piece 105 can be determined from the polarity (positive or negative). In addition, since the potential at the voltage dividing point of the two voltage dividing circuits changes in opposite directions with respect to the displacement position of the operation piece 105, the potential difference between the voltage dividing points is twice the potential of each voltage dividing circuit. The output can be taken out. As a result, there is an advantage that the detection sensitivity of the magnetic detection unit 3 can be improved.

  By the way, the magnetoresistive elements 30A to 30D constituting the magnetic detection unit 3 have temperature characteristics similar to normal resistance. Therefore, since the influence of the temperature characteristics of the magnetoresistive elements 30A to 30D also appears on the detection signal Vout of the magnetic detection unit 3, the detection signal of the magnetic detection unit 3 is caused by fluctuations in the outside air temperature or fluctuations in the indoor ambient temperature. Vout may fluctuate, and the determination unit 4 may erroneously determine the displacement position of the operation piece 105.

  Here, the magnetoresistive elements 30A and 30D and the magnetoresistive elements 30B and 30C having different magnetic detection directions Di are opposite to each other in the resistance value change due to the magnetoresistive effect, but the resistance value change due to the temperature characteristic is They are in the same direction. The temperature characteristic of the magnetoresistive element is represented by the formula Ri-0 × (1 + αΔT) (where α is a temperature coefficient and ΔT is a temperature difference).

  Therefore, if the determination unit 4 individually detects the change in the resistance values of the four magnetoresistive elements 30A to 30D, the direction of the resistance value change of the pair of magnetoresistive elements 30A and 30D or the pair of magnetoresistive elements 30B and 30C. Accordingly, the influence of the magnetic field and the temperature on the detection signal Vout can be determined.

  That is, when the detection signal Vout of the magnetic detection unit 3 increases, the determination unit 4 has a different resistance value change in the pair of magnetoresistive elements 30A and 30D (or the pair of magnetoresistive elements 30B and 30C). It is determined that the detection signal Vout has increased due to the magnetoresistive effect, and it is determined that the displacement position of the operation piece 105 has changed. However, if the resistance value changes in the same direction, the determination unit 4 determines that the detection signal Vout has increased due to the influence of the temperature change, and determines that the displacement position of the operation piece 105 has not changed.

  As described above, in the present embodiment, even when the detection signal Vout of the magnetic detection unit 3 varies due to a variation in the outside air temperature or a variation in the indoor ambient temperature, the determination unit 4 determines the displacement position of the operation piece 105. Incorrect determination can be reduced. Further, the determination unit 4 estimates the influence of the temperature in the detection signal Vout according to the direction of the resistance value change, corrects the detection signal Vout so as to reduce the influence of the temperature, and shifts from the corrected detection signal Vout. The position may be determined.

  For example, when the resistance values of the magnetoresistive elements 30B and 30C before the temperature change are R2 and R3, respectively, and the resistance values of the magnetoresistive elements 30B and 30C after the temperature change are R2 ′ and R3 ′, respectively, What is necessary is just to obtain | require the correction value Vt.

Vt = (i × R2'-i × R3 ')-(i × R2-i × R3)
By periodically calculating the correction value Vt and correcting the detection signal Vout, it is possible to improve the displacement position determination accuracy.

DESCRIPTION OF SYMBOLS 1 Permanent magnet 2 Detection apparatus main body 3 Magnetic detection part
30A, 30B magnetoresistive element
31 Bias magnet

Claims (4)

A locking / unlocking detection device for a joinery for detecting locking / unlocking of a lock for locking a fitting provided at a doorway or a window of a building, wherein the permanent magnet is attached to an operation piece of the lock that is displaced between the locking position and the unlocking position. And a magnetic detection unit that is attached to the joinery and detects a magnetic field,
The magnetic detection unit includes a plurality of magnetoresistive elements forming a voltage dividing circuit, and a bias magnet that applies a bias magnetic field to the magnetoresistive elements, a bias voltage is applied to the voltage dividing circuit, and the bias A lock / unlock detection apparatus for joinery that outputs a voltage obtained by dividing the voltage by the voltage dividing circuit as a detection signal.   The magnetic detection unit has a bridge circuit in which two voltage dividing circuits are connected in parallel, and outputs a potential difference between voltage dividing points of the voltage dividing circuit as a detection signal. Locking detection device for joinery.   A determination unit configured to determine a displacement position of the operation piece from a detection signal of the magnetic detection unit; the determination unit individually detects a resistance value change of the magnetoresistive element forming the voltage dividing circuit; 3. The displacement position is determined from the detection signal by discriminating between the influence of temperature in the change of the detection signal and the influence of the magnetic field due to the displacement position in accordance with the direction of value change. Locking detection device for joinery.   A determination unit configured to determine a displacement position of the operation piece from a detection signal of the magnetic detection unit; the determination unit individually detects a resistance value change of the magnetoresistive element forming the voltage dividing circuit; Estimating the influence of the temperature in the detection signal according to the direction of the value change, correcting the detection signal so as to reduce the influence of the temperature, and determining the displacement position from the corrected detection signal. The lock / unlock detection apparatus for joinery according to claim 2, characterized in that:

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