JP2006012504A - Non-contact switch, and position detecting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact switch hardly affected by an external magnetic field without taking measure to apply a magnetic shield to a magnetism sensor, capable of reducing production cost, and to provide a position detecting device using the same. <P>SOLUTION: The non-contact sensor 30 is provided with holes ICs 31, 32 and magnets 33, 34. The holes ICs 31, 32 and the magnets 33, 34 can relatively move between a position to be detected where the holes ICs and the magnets come close to each other, and a position distant from each other. The holes ICs 31, 32 are arranged close to each other so that magnetism sensing directions get into reversed from each other. When the magnets 33, 34 are moved to a detection position, they are located at the position close to the holes ICs 31, 32. The magnets 33, 34 are located so that the direction of magnetization get into reversed from each other. When the magnets 33, 34 are moved to the detection position, a magnetic field 38 having a direction same as the magnetism sensing direction 35 of the hole IC 31 is generated by the magnet 33, and a magnetic field 39 having a direction same as the magnetism sensing direction 36 of the hole IC 32 is generated by the magnet 34. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a non-contact switch including a magnetic sensor such as a Hall IC that is turned on and off according to the strength of a magnetic field.

  Conventionally, for example, a buckle switch is known as a non-contact switch that is turned on and off according to the strength of a magnetic field (see Patent Documents 1 and 2). These buckle switches are installed in a seat of an automobile or the like, and in a seat belt device that restrains and protects an occupant, the buckle switch detects that the tongue plate attached to the seat belt is engaged with the buckle and is locked, and This is a non-contact switch for turning off a warning lamp that prompts the user to wear the device.

Such a non-contact switch includes a Hall IC 21 as a magnetic sensor and a magnet 22 as shown in FIGS. In this non-contact switch, when the tongue is engaged with the buckle and is not locked, the magnet 22 is located away from the Hall IC 21 as shown in FIG. 13A, and the Hall IC 21 is turned off (sensor OFF). It has become. On the other hand, in this non-contact switch, when the tongue is engaged with the buckle and locked, the magnet 22 is positioned near the Hall IC 21 as shown in FIG. 13B, and the Hall IC 21 is moved by the magnetic field generated by the magnet 22. Turns on (sensor ON).
JP 2004-49358 A JP 2004-121602 A

  By the way, in the non-contact switch described above as shown in FIGS. 13A and 13B, the Hall IC 21 is turned on and off in response to the strength of the magnetic field of the magnet 22 paired therewith. For this reason, in the state where the magnet 22 is away from the Hall IC 21, the magnetic field strength of the magnet 22 is the same direction as the magnetic sensing direction (direction indicated by the arrow 23) of the Hall element that is the magnetic sensing portion of the Hall IC 21. Even when an external magnetic field exceeding 1 acts as shown in FIG. 13C, there is a possibility that a malfunction occurs in which the Hall IC 21 is turned on. In order to avoid such malfunction of the magnetic sensor due to the external magnetic field, it is necessary to take measures such as magnetically shielding the magnetic sensor such as the Hall IC 21 with a metal case or the like so as not to be affected by the external magnetic field. is there. Therefore, in Patent Document 1, the Hall IC (IC Hall element) is configured to be surrounded by a magnetic shielding base, thereby shielding the magnetic field of the external magnetic field and suppressing the influence of the external magnetic field on the Hall IC. Like to do.

  In this way, in order to prevent the magnetic sensor from malfunctioning by suppressing the influence of the external magnetic field, measures such as magnetic shielding of the magnetic sensor with a metal case or the like increase the number of parts and increase the manufacturing cost. Will be a factor.

  The present invention has been made in view of such circumstances, and the object thereof can be made less susceptible to the influence of an external magnetic field without taking measures such as magnetically shielding the magnetic sensor. It is an object of the present invention to provide a non-contact switch that can be reduced and a position detection device using the same.

In order to solve the above-mentioned problems, the invention according to claim 1 includes a magnetic field detection unit including two magnetic sensors each having a magnetic sensing portion and turned on and off according to the strength of the magnetic field, and the magnetic field detection unit. Magnetic field generation means for generating a magnetic field, and the two magnetic sensors are arranged at positions close to each other with different magnetic sensing directions in the magnetic sensing unit. The gist is that the two magnetic sensors are both turned on by the magnetic field generated by the magnetic field generating means when the generating means is displaced to the detected position approaching the magnetic field detecting means.

  According to this, when the magnetic field generating means is displaced to the detected position close to the magnetic field detecting means, the two magnetic sensors arranged at positions close to each other with different magnetic sensitive directions are generated by the magnetic field generated by the magnetic field generating means. Both are turned on. Even if a strong external magnetic field is applied to the two magnetic sensors in a state where the magnetic field generating means is away from the two magnetic sensors, the magnetic fields in the same direction are applied to the two magnetic sensors arranged at close positions with different magnetic sensing directions. Therefore, even if one of both magnetic sensors is turned on, it is unlikely that both of them are turned on. For this reason, when the two magnetic sensors are both turned on, the non-contact switch is turned on, so that the non-contact switch is turned on by the external magnetic field even though the magnetic field generating means is not displaced to the detected position. It is possible to avoid the occurrence of a malfunction that becomes a state. As a result, the ON state of the non-contact switch is detected by turning on both magnetic sensors, so that the magnetic field generating means and the magnetic field detecting means are accurately detected without being affected by an external magnetic field. be able to.

Accordingly, it is possible to make the magnetic sensor less susceptible to the influence of an external magnetic field without taking measures such as magnetically shielding the magnetic sensor, and the manufacturing cost can be reduced.
The term “magnetic sensing portion” here includes a Hall element whose output voltage changes according to the strength of the magnetic field and a magnetoresistive (MR) element whose resistance value changes according to the strength of the magnetic field. Use. The term “magnetic sensor” is used to include a Hall IC including a Hall element and an IC including a magnetoresistive (MR) element.

  According to a second aspect of the present invention, in the non-contact switch according to the first aspect, the two magnetic sensors are arranged side by side so that the magnetic sensing directions are opposite to each other, and the magnetic field generating means are relative to each other. Two magnets that are displaceable and arranged side by side so that the directions of magnetization are opposite to each other, and when the magnetic field generating means is displaced to the detected position, the two magnets are respectively connected to the two magnetic sensors. The two magnets face each other and generate a magnetic field in the same direction as one of the two magnetic sensors with one of the two magnets, and the other of the two magnets generates the magnetic field of the two magnetic sensors. The gist is to generate a magnetic field in the same direction as the other magnetic sensing direction.

According to this, the non-contact switch can take the following four operation states.
(1) When the two magnets are away from the two magnetic sensors, both magnetic sensors are turned off. (2) When the magnetic field generating means is displaced to the detected position, the two magnets face each other at positions close to the two magnetic sensors, and both magnetic sensors are turned on. (3) In the state where the two magnets are located away from the two magnetic sensors, an external magnetic field that is in the same direction as one of the magnetic sensitive directions of both magnetic sensors and exceeds the magnetic field strength of the magnets acts on both magnetic sensors. Then, one of the magnetic sensors is turned on. At this time, the other magnetic sensor is not turned on because the direction of the external magnetic field is opposite to the direction of its own magnetic sensing. (4) In a state where the two magnets are located away from the two magnetic sensors, an external magnetic field that is in the same direction as the other magnetic sensing direction of both magnetic sensors and exceeds the magnetic field strength of the magnets acts on both magnetic sensors. Then, the other magnetic sensor is turned on. At this time, one of the magnetic sensors is not turned on because the direction of the external magnetic field is opposite to the direction of its own magnetic sensing.

Thus, since the non-contact switch can take the above four operation states, the non-contact switch is in the on state when the operation state of (2) above, that is, when both magnetic sensors are in the on state. The other operating state is the off state of the switch. Thereby, the malfunction of the non-contact switch due to the external magnetic field can be avoided without taking measures such as magnetically shielding a magnetic sensor such as a Hall IC with a metal case or the like as in the prior art. Therefore, the magnetic sensor can be made less susceptible to the influence of the external magnetic field without taking measures such as magnetically shielding the magnetic sensor, and the manufacturing cost can be reduced.

  According to a third aspect of the present invention, in the non-contact switch according to the first aspect, the two magnetic sensors are disposed on both surfaces of the printed circuit board so that the magnetosensitive directions are opposite to each other and perpendicular to the both surfaces. The magnetic field generating means includes two magnets that are integrally held so that magnetic poles of the same polarity face each other at a position separated by a predetermined distance, and the magnetic field generating means includes the detected position. When the two magnets are displaced, the two magnets face each other at positions close to the two magnetic sensors, and one of the two magnets generates a magnetic field in the same direction as one of the two magnetic sensors. The gist of the present invention is to generate a magnetic field in the same direction as the other magnetic sensing direction of the two magnetic sensors by the other of the two magnets.

  According to this, since the two magnetic sensors are mounted on both surfaces of the printed circuit board so that the magnetic sensing directions are opposite to each other and vertically upward with respect to both surfaces, the two magnetic sensors are the same as the two magnetic sensors. Those with special characteristics can be used with the direction of magnetic sensitivity reversed. Thereby, it becomes easy to prepare many kinds of products according to various specifications. Further, it is possible to detect relative displacement of the two magnets and the two magnetic sensors in the displacement direction parallel to both surfaces of the printed circuit board.

  According to a fourth aspect of the present invention, in the non-contact switch according to the first aspect, the two magnetic sensors are arranged on one side of the printed circuit board so that the magnetosensitive directions are opposite to each other and parallel to the one side. Independently mounted, the magnetic field generating means includes two magnets integrally held so that magnetic poles of the same polarity face each other at positions separated by a predetermined distance, and the magnetic field generating means When the two magnets are displaced, the two magnets face each other at positions close to the two magnetic sensors, and one of the two magnets generates a magnetic field in the same direction as one of the two magnetic sensors. The gist of the present invention is to generate a magnetic field in the same direction as the other magnetic sensing direction of the two magnetic sensors by the other of the two magnets.

  According to this, the two magnetic sensors are independently mounted on one side of the printed circuit board so that the magnetic sensing directions are opposite to each other and parallel to the one side (discrete type). For this reason, as a magnetic sensor, a magnetic sensor having the same characteristics can be used with the magnetic sensitive direction reversed. Thereby, it becomes easy to prepare many kinds of products according to various specifications. In addition, it is possible to detect relative displacement of the two magnets and the two magnetic sensors in the displacement direction perpendicular to one surface of the printed circuit board.

  According to a fifth aspect of the present invention, in the non-contact switch according to the first aspect, the two magnetic sensors are disposed on both sides of the printed circuit board so that the magnetosensitive directions are opposite to each other and perpendicular to the both sides. The magnetic field generating means includes one magnet, and when the magnetic field generating means is displaced to the detected position, the direction of magnetization of the one magnet is the magnetic sensitive direction of the two magnetic sensors. The magnetic field is close to the two magnetic sensors so as to be perpendicular to the magnetic field, and the magnetic field in the same direction as one of the two magnetic sensors and the magnetic field in the same direction as the other magnetic direction by the one magnet. The gist is to generate.

According to this, since the magnet which comprises a non-contact switch with two magnetic sensors can be made into one, the number of parts can be reduced and manufacturing cost can further be reduced.
According to a sixth aspect of the present invention, in the non-contact switch according to the first aspect, the two magnetic sensors are arranged on one side of a printed circuit board so that the magnetosensitive directions are opposite to each other and parallel to the one side. Mounted independently, the magnetic field generating means includes one magnet, and when the magnetic field generating means is displaced to the detected position, the direction of magnetization of the one magnet is the magnetic sensitive direction of the two magnetic sensors. The magnetic field is close to the two magnetic sensors so as to be perpendicular to the magnetic field, and the magnetic field in the same direction as one of the two magnetic sensors and the magnetic field in the same direction as the other magnetic direction by the one magnet. The gist is to generate.

According to this, it is possible to detect relative displacement of one magnet and two magnetic sensors in a displacement direction perpendicular to one surface of the printed circuit board.
The invention according to claim 7 is the non-contact switch according to claim 5 or 6, characterized in that the magnetic field detecting means further includes magnetic bodies arranged on both sides of the two magnetic sensors.

  According to this, the magnetic field generated by one magnet by the magnetic bodies arranged on both sides of the two magnetic sensors causes the same direction as the magnetic sensing direction of one magnetic sensor and the magnetic sensing direction of the other magnetic sensor. Can be directed in both directions with the same direction. Thereby, among the magnetic fields generated by one magnet, the magnetic field components in the same direction as the magnetic sensing direction of one magnetic sensor and the magnetic field components in the same direction as the magnetic sensing direction of the other magnetic sensor can be made stronger. it can. As a result, it is not necessary to specially prepare a magnetic sensor having a characteristic in which the threshold value for turning on each magnetic sensor is lower than in the case of using two magnets.

A gist of a position detection device according to an eighth aspect of the invention is the non-contact switch according to any one of the first to seventh aspects.
According to this, by detecting the ON state of the non-contact switch by turning on both magnetic sensors, it is possible to accurately determine that the magnetic field generating means and the magnetic field detecting means are in a predetermined positional relationship without being affected by the external magnetic field. Can be detected. For example, if the position detection device is a buckle device in a seat belt device and uses a non-contact switch as the buckle switch, the lock position where the tank plate is inserted into the buckle and locked is affected by the influence of an external magnetic field. It can be detected accurately without receiving. Therefore, it is possible to realize a position detection device such as a buckle device in a seat belt device that is not easily affected by an external magnetic field without taking measures such as magnetically shielding the magnetic sensor and can reduce the manufacturing cost.

  The “position detecting device” here includes at least two members that can be displaced relative to each other, one of which is close to the other and the position where both members are separated from each other, or either one of them. Used to include devices that are configured to electrically detect the position of. For example, the “position detecting device” includes a buckle device for a seat belt that restrains and protects an occupant on a seat in an aircraft or a ship, and a position of an opening / closing member such as a door, in addition to the buckle device mounted on a vehicle such as an automobile. And a device for detecting a closed position of a window, etc., used for controlling a motor for a power window mounted on a vehicle such as an automobile.

  According to the present invention, it is possible to make the magnetic sensor less susceptible to the influence of an external magnetic field without taking measures such as magnetically shielding the magnetic sensor, and the manufacturing cost can be reduced.

  Hereinafter, embodiments of the non-contact switch embodying the present invention and a position detection device using the non-contact switch will be described with reference to the drawings. In the description of each embodiment, similar parts are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
A non-contact switch 30 according to the first embodiment will be described with reference to FIGS.
As shown in FIG. 1, the non-contact switch 30 has a magnetic sensing portion whose output voltage changes according to the strength of the magnetic field, and is a magnetic sensor 2 that turns on and off according to the strength of the magnetic field. Two Hall ICs 31 and 32 and two magnets 33 and 34 provided so as to be relatively displaceable together with respect to the two Hall ICs 31 and 32 are provided.

  In this example, Hall ICs 31 and 32 and magnets 33 and 34 are detected positions (positions shown in FIG. 2) where magnets 33 and 34 approach Hall ICs 31 and 32, and magnets 33 and 34 are separated from Hall ICs 31 and 32. It is arrange | positioned so that relative displacement is possible in the displacement direction 37 between these positions (position shown in FIG. 1).

  Each of the Hall ICs 31 and 32 includes a Hall element (not shown) as a magnetic sensing unit, and when receiving a magnetic field having a strength exceeding a predetermined threshold, the Hall ICs 31 and 32 are switched from OFF (sensor OFF) to ON (sensor OFF). Sensor ON) and an H level on signal is output.

  As shown in FIG. 1, the Hall ICs 31 and 32 are arranged adjacent to each other so that the magnetic sensing directions 35 and 36 in the respective magnetic sensing units are opposite to each other. That is, the magnetic sensing direction 35 of the Hall IC 31 faces rightward along the displacement direction 37, the magnetic sensing direction 36 of the Hall IC 32 faces leftward along the displacement direction 37, and both the magnetic sensing directions 35, 36 are parallel. In addition, the Hall ICs 31 and 32 are arranged in close proximity. The Hall ICs 31 and 32 arranged in this way are housed in, for example, a protective cover (not a magnetic shielding case) (not shown) and integrally held.

  The magnets 33 and 34 are arranged to face each other at positions close to the Hall ICs 31 and 32 when the magnets 33 and 34 are displaced to the detection positions shown in FIG. 2 (see FIG. 2). Moreover, the magnets 33 and 34 are arrange | positioned so that the direction of magnetization may become reverse direction. That is, the magnet 33 is arranged so that the magnetization direction is parallel to the magnetic sensing direction 35 and the south pole is on the left side and the north pole is on the right side. On the other hand, the magnet 34 is arranged so that the magnetization direction is parallel to the magnetic sensing direction 36 and the N pole is on the left side and the S pole is on the right side.

  With such an arrangement, when the magnets 33 and 34 are displaced to the detected position, the one magnet 33 generates a magnetic field 38 in the same direction as the magnetic sensing direction 35 of the one Hall IC 31, and the other magnet 34 The magnetic field 39 in the same direction as the magnetic sensitive direction 36 of the other Hall IC 32 is generated. Here, the “magnetization direction” refers to a direction connecting the central portions of both magnetic poles (S pole and N pole) of the magnets 33 and 34.

  As described above, in the non-contact switch 30 according to the present embodiment, the Hall ICs 31 and 32 are arranged at positions close to each other with different magnetic sensing directions 35 and 36 in the respective magnetic sensing portions. Further, when the magnets 33 and 34 are displaced to the detected positions approaching the Hall ICs 31 and 32, the Hall ICs 31 and 32 are both turned on by the magnetic fields 38 and 39 generated by the magnets 33 and 34, respectively.

  In the present embodiment, the two Hall ICs 31 and 32 constitute magnetic field detection means including two magnetic sensors that are turned on and off according to the strength of the magnetic field. Further, the two magnets 33 and 34 are provided so as to be capable of relative displacement with respect to the magnetic field detecting means, and constitute a magnetic field generating means for generating a magnetic field.

The non-contact switch 30 having such a configuration can take the following four operating states.
(1) When the magnets 33 and 34 are located away from the Hall ICs 31 and 32 as shown in FIG. 1, both the Hall ICs 31 and 32 are turned off.

  (2) As shown in FIG. 2, when the magnets 33 and 34 are displaced to the detected positions, the Hall IC 31 is turned on by the magnetic field 38 generated by the magnet 33, and the Hall IC 32 is turned on by the magnetic field 39 generated by the magnet 34. become.

  (3) As shown in FIG. 3, in the state where the magnets 33 and 34 are located away from the Hall ICs 31 and 32, the external direction exceeds the magnetic field strength of the magnet 33 in the same direction as the magnetic sensing direction 35 of the Hall IC 31. When a magnetic field (a magnetic field having a strength exceeding a predetermined threshold) acts on the Hall ICs 31 and 32, the Hall IC 31 is turned on. At this time, the Hall IC 32 is not turned on because the direction of the external magnetic field is opposite to the magnetic sensing direction 36 of itself.

  (4) Similar to (3) above, the magnets 33 and 34 are located away from the Hall ICs 31 and 32, and in the same direction as the magnetic sensing direction 36 of the Hall IC 32 and exceed the magnetic field strength of the magnet 34. When the external magnetic field acts on the Hall ICs 31 and 32, the Hall IC 32 is turned on. At this time, the Hall IC 31 is not turned on because the direction of the external magnetic field is opposite to the magnetic sensing direction 35 of itself.

  As described in (3) and (4) above, even when a strong external magnetic field acts on the Hall ICs 31 and 32 in a state where the magnets 33 and 34 are located away from the Hall ICs 31 and 32, they are close to each other. It is presumed that a magnetic field in the same direction acts on both Hall ICs 31 and 32 arranged at the position. Further, as described above, since the Hall ICs 31 and 32 are usually housed in a protective cover (not shown), an external magnetic field strong enough to react both the Hall ICs 31 and 32 acts on the Hall ICs 31 and 32. It is presumed that there are few external magnetic fields that have a sudden change in magnetic field direction that turns on both Hall ICs 31 and 32 simultaneously. Therefore, in a state where the magnets 33 and 34 are located away from the Hall ICs 31 and 32, even if one of the Hall ICs 31 and 32 is turned on by the external magnetic field, both the Hall ICs 31 and 32 are simultaneously turned on. It is considered that there is very little.

According to 1st Embodiment comprised as mentioned above, there exist the following effects.
When the magnets 33 and 34 are displaced to the detected positions shown in FIG. 2, the Hall ICs 31 are arranged in close proximity with the magnetic sensing directions 35 and 36 being changed by the magnetic fields 38 and 39 generated by the magnets 33 and 34, respectively. , 32 are both turned on. Even if a strong external magnetic field acts on the Hall ICs 31 and 32 in a state where the magnets 33 and 34 are located away from the Hall ICs 31 and 32, the Hall ICs 31 and 32 arranged at close positions with different magnetic sensing directions are used. Therefore, even if one of the Hall ICs 31 and 32 is turned on, it is unlikely that both of them are turned on. For this reason, when the Hall ICs 31 and 32 are both turned on, the contactless switch 30 is turned on, so that the Hall ICs 31 and 32 are both turned on by the external magnetic field and the contactless switch 30 is turned on. Can be avoided.

  For this reason, by setting the state in which both of the two magnetic sensors are turned on to the on state of the non-contact switch, the non-contact switch 30 is caused by the external magnetic field even though the magnets 33 and 34 are not displaced to the detection position. It is possible to avoid the occurrence of a malfunction that turns on. As a result, the on-state of the non-contact switch 30 is detected when both Hall ICs 31 and 32 are turned on, so that the magnets 33 and 34 and the Hall ICs 31 and 32 are affected by an external magnetic field. And can be detected accurately.

Therefore, the Hall ICs 31 and 32 can be made less susceptible to the influence of the external magnetic field without taking measures such as magnetic shielding, and the manufacturing cost can be reduced.
Since the non-contact switch 30 can take the above four operation states, the non-contact switch 30 is turned on when the operation state of (2) above, that is, when both Hall ICs 31 and 32 are turned on, The non-contact switch 30 can be turned off when the operating state is any one of the above (1), (3), and (4).

  In this way, when both Hall ICs 31 and 32 are turned on, the non-contact switch 30 is turned on, so that the magnetic sensor such as the Hall IC is magnetically shielded by a metal case or the like as in the prior art. Without taking measures such as, it is possible to avoid malfunction of the non-contact switch 30 due to an external magnetic field.

Accordingly, it is possible to make the Hall ICs 31 and 32 less susceptible to the influence of an external magnetic field without taking measures such as magnetically shielding both Hall ICs 31 and 32, and the manufacturing cost can be reduced.
(Position detection device using non-contact switch)
Next, an example of a position detection device using the non-contact switch according to the present invention will be described with reference to FIG.

  FIG. 4 shows a buckle device in a seat belt device using the non-contact switch 30 as a buckle switch as an example of a position detection device using a non-contact switch. This buckle device is used in a seat belt device that is mounted on a seat of an automobile or the like and restrains and protects an occupant, and includes a tongue plate attached to the seat belt and a buckle fixed to the seat side. When the tongue plate is inserted into the buckle to the locked position and engaged, the tongue plate is locked to the buckle, and the occupant is restrained and protected by the seat belt.

  In this buckle device, when the lock position where the tongue plate is locked to the buckle is detected by the non-contact switch 30 as a buckle switch, the warning lamp that prompts the occupant to attach the seat belt is turned off.

  In such a buckle device, the two Hall ICs 31 and 32 and the two magnets 33 and 34 constituting the non-contact switch 30 are arranged in the buckle, for example, similarly to the buckle device described in Patent Document 2 above. . The Hall ICs 31 and 32 and the magnets 33 and 34 are inserted into the buckle to the lock position, and when the tongue plate is locked to the buckle, the magnets 33 and 34 are moved to the Hall ICs 31 and 34 as shown in FIG. It moves from the position away from 32 to the detected position in FIG. At this time, as described above, the Hall ICs 31 and 32 are both turned on, and an H level on signal is output.

  As shown in FIG. 4, this buckle device includes the non-contact switch 30 as a buckle switch, the ECU 40, a battery 41 that supplies an operating voltage to the Hall ICs 31 and 32 of the non-contact switch 30 and the ECU 40, and a seat for the passenger And a warning lamp 42 for urging the user to wear the belt.

  The ECU 40 lights the warning lamp 42 when both the Hall ICs 31 and 32 are off (sensor OFF) and when only one of them is on (sensor ON), and both the Hall ICs 31 and 32 are both on ( When the sensor is ON), it is determined that the non-contact switch 30 has been turned on upon detecting the lock position, and the warning lamp 42 is turned off.

  According to the buckle device configured as described above, by using the non-contact switch 30 as a buckle switch, the on state can be detected by turning on both the Hall ICs 31 and 32. Thereby, it can be accurately detected that the tongue plate is in the locked position (the magnetic field generating means and the magnetic field detecting means are in a predetermined positional relationship) without being affected by the external magnetic field.

  That is, it is possible to avoid a malfunction that the non-contact switch 30 is turned on by an external magnetic field when the tongue plate is not locked to the buckle, and the lock position can be detected without being affected by the external magnetic field. Therefore, it is possible to realize a buckle device in a seat belt device that is not easily affected by an external magnetic field without taking measures such as magnetically shielding the Hall ICs 31 and 32 and that can reduce the manufacturing cost.

(Second Embodiment)
A non-contact switch 50 according to the second embodiment will be described with reference to FIGS.
As shown in FIG. 5, the non-contact switch 50 has a magnetic sensitive part whose output voltage changes according to the strength of the magnetic field, and 2 as a magnetic sensor that turns on and off according to the strength of the magnetic field. Two Hall ICs 51 and 52 and two magnets 53 and 54 disposed so as to be relatively displaceable together with respect to the two Hall ICs 51 and 52 are provided.

  Each of the Hall ICs 51 and 52 includes a Hall element (not shown) as a magnetic sensing unit, and when receiving a magnetic field with a strength exceeding a predetermined threshold, the Hall ICs 51 and 52 are switched from OFF (sensor OFF) to ON (sensor OFF). Sensor ON) and an H level on signal is output.

  The two Hall ICs 51 and 52 are arranged on the both surfaces 55a and 55b of the printed circuit board 55 so that the magnetic sensing directions 56 and 57 in the respective magnetic sensing portions are opposite to each other and are vertically upward with respect to the both surfaces 55a and 55b. It is mounted (surface mounted). Therefore, the Hall ICs 51 and 52 have a structure in which Hall ICs having the same characteristics (for example, Hall ICs having the same threshold value) can be used with their magnetic sensitive directions reversed.

  In this example, Hall ICs 51 and 52 and magnets 53 and 54 are detected positions (positions shown in FIG. 6) where magnets 53 and 54 approach Hall ICs 51 and 52, and magnets 53 and 54 are Hall ICs 51 and 52. And a position away from the position (position shown in FIG. 1) so as to be relatively displaceable in a displacement direction 58 parallel to both surfaces 55a and 55b of the printed circuit board 55. The Hall ICs 51 and 52 are, for example, housed in a protective cover (not a magnetic shielding case) (not shown) and integrally held.

  The two magnets 53 and 54 are integrally held by a holding member 59 that is a rigid body so that magnetic poles of the same polarity (in this example, S poles) face each other at positions separated by a predetermined distance. The predetermined distance is a distance between both end surfaces of the Hall ICs 51 and 52 such that the Hall ICs 51 and 52 can be positioned between the magnets 53 and 54 when the two magnets 53 and 54 are displaced to the detected positions in FIG. It is getting bigger.

  The magnets 53 and 54 are arranged so as to face each other at positions close to the Hall ICs 51 and 52 when displaced to the detected positions shown in FIG. That is, the magnet 53 faces the Hall IC 51 so that the magnetization direction (the left-right direction in FIG. 6) is parallel to the magnetic sensing direction 56 of the Hall IC 51 and the S pole faces the Hall IC 51. On the other hand, the magnet 54 faces the Hall IC 52 so that the magnetization direction (the horizontal direction in the figure) is parallel to the magnetic sensing direction 57 of the Hall IC 52 and the S pole faces the Hall IC 52. ing.

  With such an arrangement, when the magnets 53 and 54 are displaced to the detection position, one magnet 53 generates a magnetic field 60 in the same direction as the magnetic sensing direction 56 of one Hall IC 51, and the other magnet 54 The magnetic field 61 in the same direction as the magnetic sensitive direction 57 of the other Hall IC 52 is generated.

As described above, in the non-contact switch 50 according to the present embodiment, the two Hall ICs 51 and 52 are arranged at positions close to each other with different magnetic sensing directions 56 and 57 in the respective magnetic sensing portions, and the magnets 53 and 54 are arranged. When displaced to the detected position, the Hall ICs 51 and 52 are both turned on by the magnetic fields 60 and 61 generated by the magnets 53 and 54, respectively.

  In this embodiment, the two Hall ICs 51 and 52 and the printed circuit board 55 constitute magnetic field detection means including two magnetic sensors that are turned on and off according to the strength of the magnetic field. Further, the two magnets 53 and 54 and the holding member 59 constitute a magnetic field generating means that is provided so as to be relatively displaceable with respect to the magnetic field detecting means and generates a magnetic field.

According to 2nd Embodiment comprised as mentioned above, in addition to the effect which the said 1st Embodiment show | plays, there exist the following effects.
The Hall ICs 51 and 52 are mounted on both surfaces 55a and 55b of the printed circuit board 55 so that the magnetic sensing directions 56 and 57 are opposite to each other and face vertically upward with respect to both surfaces 55a and 55b (surface mounting type). ). For this reason, as the Hall ICs 51 and 52, Hall ICs having the same characteristics (for example, Hall ICs having the same threshold value) can be used with their magnetic sensing directions reversed. Thereby, it becomes easy to prepare many kinds of products according to various specifications.

It can be detected that the magnets 53 and 54 and the Hall ICs 51 and 52 are relatively displaced in the displacement direction 58 parallel to the both surfaces 55a and 55b of the printed circuit board 55.
(Third embodiment)
A non-contact switch 50A according to the third embodiment will be described with reference to FIGS.

  This non-contact switch 50A has Hall ICs 71 and 72 similar to the Hall ICs 51 and 52 shown in FIG. 5 on one side 75a of the printed circuit board 75, and the magnetic sensitive directions 73 and 74 in the respective magnetic sensitive portions are opposite to each other. In addition, there is a feature in the configuration that is independently mounted so as to be parallel to the single side 75a. Other configurations are the same as those of the second embodiment.

  In this example, the Hall ICs 71 and 72 and the magnets 53 and 54 are detected positions (positions shown in FIG. 8) where the magnets 53 and 54 approach the Hall ICs 71 and 72, and the magnets 53 and 54 are separated from the Hall ICs 71 and 72. 7 (position shown in FIG. 7) so as to be relatively displaceable in a displacement direction 76 perpendicular to one surface 75 a of the printed circuit board 75.

7 and 8, reference numerals 77 and 78 denote connection terminals.
As described above, in the non-contact switch 50A according to the present embodiment, the two Hall ICs 71 and 72 are arranged at positions close to each other with different magnetic sensing directions 73 and 74 in the respective magnetic sensing portions, and the magnets 53 and 54 are disposed. When displaced to the detected position shown in FIG. 8, the Hall ICs 71 and 72 are both turned on by the magnetic fields 60 and 61 generated by the magnets 53 and 54, respectively.

According to 3rd Embodiment comprised as mentioned above, in addition to the effect which the said 1st Embodiment show | plays, there exist the following effects.
The Hall ICs 71 and 72 are independently mounted on one surface 75a of the printed circuit board 75 so that the magnetic sensing directions 73 and 74 are opposite to each other and parallel to the one surface 75a (discrete type). For this reason, as the Hall ICs 71 and 72, Hall ICs having the same characteristics (for example, Hall ICs having the same threshold value) can be used with their magnetic sensitive directions reversed. Thereby, it becomes easy to prepare many kinds of products according to various specifications.

It can be detected that the magnets 53 and 54 and the Hall ICs 71 and 72 are relatively displaced in the displacement direction 76 perpendicular to the one surface 75a of the printed circuit board 75.
(Fourth embodiment)
A non-contact switch 80 according to the fourth embodiment will be described with reference to FIGS.

  The non-contact switch 80 includes two Hall ICs 51 and 52 mounted on both surfaces 55a and 55b of the printed circuit board 55, one magnet 81, two Hall ICs 51, And magnetic bodies 82 and 82 disposed on both sides of 52.

  In this example, the Hall ICs 51 and 52 and the magnet 81 are detected positions where the magnet 81 approaches the Hall ICs 51 and 52 (position shown in FIG. 10) and positions where the magnet 81 is separated from the Hall ICs 51 and 52 (see FIG. 9). (Position shown) is arranged so as to be relatively displaceable in a displacement direction 84 parallel to both surfaces 55a and 55b of the printed circuit board 55.

  When the magnet 81 is displaced to the detected position shown in FIG. 10, the magnet 81 is close to the Hall ICs 51 and 52 so that the magnetization direction is perpendicular to the magnetic sensing directions 56 and 57 of the Hall ICs 51 and 52. Further, when the magnet 81 is displaced to the detection position, the magnet 81 generates a magnetic field 83a in the same direction as the magnetic sensing direction 56 of one Hall IC 51 and a magnetic field 83b in the same direction as the other magnetic sensing direction 57. It is supposed to let you. The magnetic field 83a and the magnetic field 83b are part of the magnetic field component of the magnetic field 83 generated by the magnet 81.

  A magnetic field 83 generated by the magnet 81 acts mainly in a direction perpendicular to the magnetic sensing directions 56 and 57. Of these magnetic fields 83, magnetic bodies 82 and 82 are provided in order to strengthen the components of the magnetic field 83 a in the same direction as the magnetic sensing direction 56 and the magnetic field 83 b in the same direction as the magnetic sensing direction 57.

  As described above, in the non-contact switch 80 according to the present embodiment, the two Hall ICs 51 and 52 are arranged at positions close to each other with different magnetic sensing directions 56 and 57 in the respective magnetic sensing portions, and the magnet 81 is shown in FIG. The Hall ICs 51 and 52 are both turned on by a part of the magnetic field 83a and 83b of the magnetic field 83 generated by the magnet 81.

  In the present embodiment, the two Hall ICs 51 and 52, the printed circuit board 55, and the magnetic bodies 82 and 82 constitute magnetic field detection means including two magnetic sensors that are turned on and off according to the strength of the magnetic field. In addition, a single magnet 81 is provided so as to be capable of relative displacement with respect to the magnetic field detection means, and constitutes a magnetic field generation means for generating a magnetic field.

According to 4th Embodiment comprised as mentioned above, in addition to the effect which the said 2nd Embodiment show | plays, there exist the following effects.
Since the magnets constituting the non-contact switch 80 together with the two Hall ICs 51 and 52 can be made one, the number of parts can be reduced and the manufacturing cost can be further reduced.

  The magnetic bodies 82 and 82 arranged on both sides of the two Hall ICs 51 and 52 cause the magnetic field 83 generated by one magnet 81 to be in the same direction as the magnetic sensing direction 56 of one Hall IC 51 and the other Hall IC 52. It can be directed in both directions, the same as the magnetic sensing direction 57. Thereby, the components of the magnetic field 83 a in the same direction as the magnetic sensing direction 56 and the magnetic field 83 b in the same direction as the magnetic sensing direction 57 in the magnetic field 83 generated by one magnet 81 can be further strengthened. As a result, it is not necessary to specially prepare a Hall IC having a characteristic that the threshold value for turning on each Hall IC 51, 52 is lower than that in the case of using two magnets as in the above embodiments.

(Fifth embodiment)
A non-contact switch 90 according to a fifth embodiment will be described with reference to FIGS.
The non-contact switch 90 includes Hall ICs 91 and 92 similar to the Hall ICs 51 and 52 shown in FIG. 9 on one side 95a of the printed circuit board 95, in which the magnetic sensing directions 93 and 94 are opposite to each other. In addition, there is a feature in the configuration that is independently mounted so as to be parallel to the one side 95a. Other configurations are the same as those in the fourth embodiment. 11 and 12, reference numerals 97 and 98 are connection terminals, and reference numeral 99 is a displacement direction.

  As described above, in the non-contact switch 90 according to the present embodiment, the two Hall ICs 91 and 92 are arranged at positions close to each other with different magnetic sensing directions 93 and 94 in the respective magnetic sensing portions, and the magnet 81 is shown in FIG. The Hall ICs 91 and 92 are both turned on by a part of the magnetic field 83a and 83b of the magnetic field 83 generated by the magnet 81.

According to 5th Embodiment comprised as mentioned above, in addition to the effect which the said 4th Embodiment show | plays, there exist the following effects.
It can be detected that one magnet 81 and two Hall ICs 91 and 92 are relatively displaced in a displacement direction 99 perpendicular to one surface 95a of the printed circuit board 95.

In addition, this invention can also be changed and embodied as follows.
In each of the above embodiments, the magnetic field detection means including two magnetic sensors arranged in close proximity with different magnetic sensing directions, and the magnetic field generation that is provided so as to be relatively displaceable with respect to the magnetic field detection means and generates a magnetic field However, the present invention is not limited to these configurations. The present invention can be applied to a configuration in which a plurality of the magnetic field detecting means and the magnetic field generating means are provided in order to prevent further malfunction although the cost increases.

In each of the above embodiments, the Hall IC is used as the magnetic sensor, but an IC including a magnetoresistive (MR) element may be used instead of the Hall IC as the magnetic sensor.
In each of the above embodiments, one or two magnets constituting the magnetic field generating means are provided linearly relative to the two Hall ICs constituting the magnetic field detecting means, for example, relative to the displacement direction 37 in FIG. However, the present invention is not limited to such a configuration. For example, the present invention is also applied to a configuration in which one or two magnets are displaced relative to each other in a non-linear manner, such as relative rotation with respect to two Hall ICs, and are displaced to a detected position close to the two Hall ICs. Is done.

  In each of the above embodiments, the configuration examples of the non-contact switch have been described. However, the present invention is not limited to these configuration examples. That is, according to the present invention, at the detected position where one or two magnets approach two Hall ICs (for example, the position shown in FIG. 2), the two Hall ICs are joined together by a magnetic field generated by one or two magnets. The present invention can be widely applied to those that are turned on.

  -In the said 1st Embodiment shown in FIG. 1, you may make it the structure which provided the magnetic shielding board between the two magnets 33 and 34 arrange | positioned in the close position. With this configuration, the magnetic fields 38 and 39 generated by the two magnets 33 and 34 can be prevented from affecting each other.

  In the second and third embodiments shown in FIGS. 5 and 7, the two magnets 53 and 54 are rigid holding members 59 such that magnetic poles of the same polarity face each other at a position separated by a predetermined distance. However, the present invention is not limited to such a configuration. The two magnets 53 and 54 may be configured to be integrally held by the holding case or the holding plate so that the magnetic poles having the same polarity face each other at a position separated by a predetermined distance. For example, the holding plate that holds the two magnets 53 and 54 has two Hall ICs 51 and 52 or 71 and 72 as shown in FIG. 6 and FIG. What is necessary is just to provide a notch etc. so that it can be located in the both sides of.

In the fourth and fifth embodiments shown in FIGS. 9 and 11, the magnetic bodies 82 and 82 are arranged on both sides of the two Hall ICs 51 and 52 or 91 and 92, respectively. , 82 is not applicable. If the strength of the magnetic field generated by the magnet 81 is sufficiently large, or if not, the magnetic bodies 82 and 82 need not be used when a Hall IC with a low threshold value is used. It is.

  In the position detection device using the non-contact switch shown in FIG. 4, the buckle device in the seat belt device using the non-contact switch 30 as the buckle switch has been described as an example, but the position using the non-contact switch according to the present invention is described. The detection device is not limited to this. The present invention includes at least two members that can be displaced relative to each other, and electrically detects both of a position and a position where both members are separated when one of them approaches the other. The present invention can be widely applied to the position detecting device configured as described above. For example, the present invention includes a buckle device for a seat belt that restrains and protects an occupant on a seat in an aircraft or a ship, and a device that detects the position of an opening / closing member such as a door, in addition to the buckle device mounted on a vehicle such as an automobile. It is used for control of a motor for a power window mounted on a vehicle such as an automobile, and can be applied to a “position detecting device” such as a device for detecting a closed position of a window.

The top view which shows the non-contact switch which concerns on 1st Embodiment. Explanatory drawing which shows the ON state of the non-contact switch. Explanatory drawing when an external magnetic field acts on the non-contact switch. The block diagram which shows the electrical constitution of the position detection apparatus using a non-contact switch. The top view which shows the non-contact switch which concerns on 2nd Embodiment. Explanatory drawing which shows the ON state of the non-contact switch. The top view which shows the non-contact switch which concerns on 3rd Embodiment. Explanatory drawing which shows the ON state of the non-contact switch. The top view which shows the non-contact switch which concerns on 4th Embodiment. Explanatory drawing which shows the ON state of the non-contact switch. The top view which shows the non-contact switch which concerns on 5th Embodiment. Explanatory drawing which shows the ON state of the non-contact switch. (A) Top view which shows the conventional non-contact switch, (b) Explanatory drawing which shows the ON state of the non-contact switch, (c) Explanatory drawing when an external magnetic field acts on the non-contact switch.

Explanation of symbols

  30, 50, 50A, 80, 90 ... non-contact switch, 31, 32, 51, 52, 71, 72, 91, 92 ... Hall IC, 33, 34, 53, 54, 81 ... magnet, 38, 39, 60 , 61, 83, 83a, 83b ... magnetic field, 35, 36, 56, 57, 73, 74, 93, 94 ... magnetic sensitive direction, 55, 75, 95 ... printed circuit board, 55a, 55b ... double-sided, 75a ... single-sided, 82: Magnetic material.

Claims (8)

A magnetic field detection means including two magnetic sensors each having a magnetic sensing portion and being turned on and off according to the strength of the magnetic field;
A magnetic field generating means provided to be relatively displaceable with respect to the magnetic field detecting means and generating a magnetic field,
The two magnetic sensors are arranged at positions close to each other with different magnetic sensing directions in the magnetic sensing unit,
A non-contact switch configured to turn on both of the two magnetic sensors by a magnetic field generated by the magnetic field generating means when the magnetic field generating means is displaced to a detected position close to the magnetic field detecting means. . The contactless switch according to claim 1,
The two magnetic sensors are arranged side by side so that the magnetosensitive direction is opposite,
The magnetic field generating means includes two magnets arranged side by side so that they can be relatively displaced together and the directions of magnetization are reversed.
When the magnetic field generating means is displaced to the detected position, the two magnets face each other in proximity to the two magnetic sensors, and one of the two magnets senses one of the two magnetic sensors. A non-contact switch that generates a magnetic field in the same direction as a magnetic direction and generates a magnetic field in the same direction as the other magnetic sensing direction of the two magnetic sensors by the other of the two magnets. The contactless switch according to claim 1,
The two magnetic sensors are mounted on both sides of a printed circuit board so that the magnetosensitive directions are opposite to each other and vertically upward with respect to the both sides,
The magnetic field generating means includes two magnets integrally held so that magnetic poles of the same polarity face each other at positions separated by a predetermined distance,
When the magnetic field generating means is displaced to the detected position, the two magnets face each other in proximity to the two magnetic sensors, and one of the two magnets senses one of the two magnetic sensors. A non-contact switch that generates a magnetic field in the same direction as a magnetic direction and generates a magnetic field in the same direction as the other magnetic sensing direction of the two magnetic sensors by the other of the two magnets. The contactless switch according to claim 1,
The two magnetic sensors are independently mounted on one side of a printed circuit board so that the magnetosensitive directions are opposite to each other and parallel to the one side,
The magnetic field generating means includes two magnets integrally held so that magnetic poles of the same polarity face each other at positions separated by a predetermined distance,
When the magnetic field generating means is displaced to the detected position, the two magnets face each other in proximity to the two magnetic sensors, and one of the two magnets senses one of the two magnetic sensors. A non-contact switch that generates a magnetic field in the same direction as a magnetic direction and generates a magnetic field in the same direction as the other magnetic sensing direction of the two magnetic sensors by the other of the two magnets. The contactless switch according to claim 1,
The two magnetic sensors are mounted on both sides of a printed circuit board so that the magnetosensitive directions are opposite to each other and vertically upward with respect to the both sides,
The magnetic field generating means includes one magnet,
When the magnetic field generating means is displaced to the detected position, the one magnet is close to the two magnetic sensors so that the direction of magnetization is perpendicular to the magnetic sensitive direction of the two magnetic sensors. A non-contact switch, wherein two magnets generate a magnetic field in the same direction as one of the two magnetic sensors and a magnetic field in the same direction as the other magnetic direction. The contactless switch according to claim 1,
The two magnetic sensors are independently mounted on one side of a printed circuit board so that the magnetosensitive directions are opposite to each other and parallel to the one side,
The magnetic field generating means includes one magnet,
When the magnetic field generating means is displaced to the detected position, the one magnet is close to the two magnetic sensors so that the direction of magnetization is perpendicular to the magnetic sensitive direction of the two magnetic sensors. A non-contact switch, wherein two magnets generate a magnetic field in the same direction as one of the two magnetic sensors and a magnetic field in the same direction as the other magnetic direction. The non-contact switch according to claim 5 or 6,
The non-contact switch, wherein the magnetic field detecting means further includes a magnetic body disposed on both sides of the two magnetic sensors. A position detection device comprising the non-contact switch according to claim 1.

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