JP4369577B2 - Inductive switch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inductive switch.
[0002]
[Prior art]
In the antitheft system for automobiles, for example, an inductive switch has been proposed by the present applicant as means for detecting opening and closing of a bonnet or the like (Japanese Patent Application No. 11-302530).
The inductive switch has a first core member that has a coil and is attached to the fixed side, and a second core member that is attached to the movable side so as to face the first core member, and detects abnormal opening and closing. In addition, it is used to activate alarm means such as an alarm lamp and an alarm buzzer. When this inductive switch is used as a theft detection means of an antitheft system for an automobile, for example, the first core member is attached to a fixed member in the engine room. On the other hand, in consideration of attachment to the vehicle body, the second core member is provided with fixing means such as screws in advance, and by this fixing means, a position corresponding to the first core member, for example, a reinforcing rib on the bonnet side is provided. It is attached.
[0003]
[Problems to be solved by the invention]
By the way, when the inductive switch is used as the anti-theft detection means of the anti-theft system of an automobile as described above, a screwdriver or the like is forced through the gap of the bonnet, and the first core member or the second core member is forcibly removed. It can be activated or deactivated. For this reason, the inductive switch does not have a sufficient protection function against contact from the outside in order to be used in an antitheft system for automobiles.
[0004]
The present invention is an improvement of the inductive switch, and an object thereof is to provide an inductive switch with improved reliability by blocking external contact with the first or second core member.
[0005]
[Means for Solving the Problems]
In order to achieve the above object in the present invention, the first core member is made of an electrically insulating magnetic material, and is molded from a coil wound around a coil groove in a ring shape, and the electrically insulating magnetic material, A second core member provided in a ring shape inside the first core member so as to be vertically insertable and forming a magnetic circuit in cooperation with the first core member, the first core member wherein upon actuation the second core member and away from relatively close inserted or withdrawn, the a inductive switch for detecting the relative position of the second core member and the first core member A blocking member that covers the periphery of the first core member and the second core member, is formed in a cap shape to block contact from the outside, and the second core member is attached to the inside of the cap shape Provided It was a structure.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the inductive switch of the present invention is used as a theft detection means of an automobile antitheft system will be described in detail with reference to FIGS.
As shown in FIG. 1, the inductive switch 1 includes a first core member 2, a second core member 5, and a blocking member 6, and the first core member 2 and the second core member 5 are relatively close to each other or separated from each other. During the operation, the relative position between the members 2 and 5 is detected.
[0008]
The first core member 2 is provided on an upper portion of a cylindrical bobbin 3, and a coil 2a wound around a coil groove 3a is molded into a ring shape by a core 2b made of an electrically insulating soft magnetic material, and a second inside is formed. The core member 5 is inserted. The first core member 2 is attached to the attachment base Bse in the engine room by the attachment cylinder portion 3b of the bobbin 3. Here, the bobbin 3 is not shown, but the other end of the bus bar 4 whose one end is connected to the coil 2a extends into the lower cylinder 3c as shown in FIG.
[0009]
The second core member 5 forms a magnetic circuit in cooperation with the first core member 2. The second core member 5 is a cylindrical member having an insertion hole 5a, and is a reinforcement of the bonnet Bnt that is the second member via the blocking member 6, more specifically, the bonnet Bnt corresponding to the first core member 2. It is attached to the rib R. The second core member 5 is made of an electrically insulating soft magnetic material like the core 2b of the first core member 2, and is made of a soft magnetic material, for example, a soft magnetic ferrite powder such as Ni-Zn based ferrite or Mn-Zn based ferrite. Is molded by mixing a predetermined amount in a synthetic resin such as nylon or polyphenylene sulfide (PPS), or mixed with a soft magnetic material such as Ni-Zn ferrite or Mn-Zn ferrite and sintered. Things can be used. The content of the soft magnetic material is 10% by volume or more and 70% by volume or less.
[0010]
As shown in FIG. 1, the blocking member 6 is formed by forming a plurality of engaging protrusions 6b on the upper portion of a cap-shaped main body 6a and a support portion 6d having a screw hole 6c protruding downward in the center. Has been.
The inductive switch 1 is configured as described above, and the first core member 2 is attached to the attachment base Bse by inserting the attachment cylinder portion 3b into the opening Op.
[0011]
On the other hand, the second core member 5 is attached to the reinforcing rib R of the bonnet Bnt as follows. First, the blocking protrusion 6 is attached to the reinforcing rib R by engaging the engaging protrusion 6 b with the engaging hole H formed in the reinforcing rib R. Next, the 2nd core member 5 is positioned to the support part 6d, and it attaches to the interruption | blocking member 6 with the volt | bolt 7 penetrated to the insertion hole 5a.
As a result, in the inductive switch 1, as shown in FIG. 1, the periphery of the first core member 2 and the second core member 5 is covered by the blocking member 6 in which the main body 6 a is formed in a cap shape. For this reason, the inductive switch 1 has the first core member because the contact with the first core member 2 and the second core member 5 is blocked by the blocking member 6 even if a driver is inserted through the gap of the bonnet Bnt. 2 and the 2nd core member 5 cannot be removed or broken. Therefore, the inductive switch 1 has an increased protection function against contact from the outside and improves reliability.
[0012]
Here, when the blocking member provided in the inductive switch 1 is embedded inside the reinforcing rib R like the blocking member 10 shown in FIG. 2, the effect of blocking contact from the outside is further enhanced. As shown in FIG. 2, the blocking member 10 has a plurality of engaging projections 10b formed on the outer periphery of the lower part of a cap-shaped main body 10a, and a support portion 10d having a screw hole 10c protruding downward in the center. Is formed.
[0013]
Here, in the following description including the description regarding the interruption | blocking member 10, the overlapping description is abbreviate | omitted by using the same code | symbol about the same component as the inductive switch 1. FIG.
Further, the reinforcing rib R of the bonnet Bnt shown in FIGS. 1 and 2 may be protruded downward in a ring shape so as to surround the inductive switch 1 as shown in FIG. In this case, the second core member 5 is attached to the reinforcing rib R via the support member 13. The support member 13 is formed with a support portion 13c having a screw hole 13b in the center of the substrate 13a. If comprised in this way, the inductive switch 1 will further increase the effect which interrupts the contact from the outside by the interruption | blocking member 12. FIG.
[0014]
On the other hand, in the inductive switch, like the inductive switch 20 shown in FIG. 4, the first core member 21 and the second core member 25 are arranged to face each other, and the first core member 21 and the second core member 25 are opened and closed by opening and closing the bonnet Bnt. The type which detects the position of the 1st core member 21 and the 2nd core member 25 when these approach and separate may be sufficient.
[0015]
At this time, the first core member 21 is formed in a disc shape and is disposed in a recess 22 a formed in the upper portion of the cylindrical bobbin 22. In the first core member 21, a coil 21a is molded by a core 21b made of an electrically insulating soft magnetic material. The first core member 21 is attached to the attachment base Bse in the engine room by the attachment cylinder portion 22b of the bobbin 22. Here, although not shown, the bobbin 22 has the other end of the bus bar 23 having one end connected to the coil 21a extending into the lower cylinder 22c as shown.
[0016]
The second core member 25 is a disk-like member having a screw hole 25a in the center, and is attached to the reinforcing rib R of the bonnet Bnt as the second member via the blocking member 26. The second core member 25 is formed of an electrically insulating soft magnetic material used in the inductive switch 1 together with the core 21 b of the first core member 21.
As shown in FIG. 4, the blocking member 26 has a plurality of engaging protrusions 26b formed on the upper portion of a cap-shaped main body 26a, and a screw hole 26c formed in the center.
[0017]
The inductive switch 20 is configured as described above, and the first core member 21 is attached to the attachment base Bse by inserting the attachment cylinder portion 22b into the opening Op.
On the other hand, the second core member 25 is attached to the reinforcing rib R of the bonnet Bnt as follows. First, the blocking member 26 is attached to the reinforcing rib R by engaging the engaging protrusion 26 b with the engaging hole H formed in the reinforcing rib R. Next, the second core member 25 is positioned on the blocking member 26 from below and attached to the blocking member 26 with a bolt 27 inserted through the insertion hole 25a.
[0018]
As a result, as shown in FIG. 4, the inductive switch 20 covers the periphery of the first core member 21 and the second core member 25 by the blocking member 26 in which the main body 26 a is formed in a cap shape. For this reason, the inductive switch 20, like the inductive switch 1, is blocked from contact with the first core member 21 and the second core member 25 by the blocking member 26, and the protection function against contact from the outside is increased, and the reliability is increased. improves.
[0019]
In addition, the said embodiment demonstrated the case where the inductive switch of this invention was used as a theft detection means of the antitheft system of a motor vehicle. However, in the inductive switch of the present invention, the first and second core members are attached to the first and second members that are relatively close to and away from each other, and the first core member and the second core member are attached. For detecting the relative position to the core member, for example, means for detecting opening / closing of a door of an automobile, a house, etc., means for detecting whether a child seat is attached or not, or whether a child seat is properly attached, trunk lid It can be used as a means for detecting the opening / closing of a sheet, a means for detecting the proper attachment of a retractable sheet, a detection means for confirming whether the sheet is set in an optimum state, etc., and is limited to the above embodiment is not.
[0020]
At this time, the inductive switch of the present invention, for example, the inductive switch 1 shown in FIG. 1, is used in an automobile in which vibrations act as it travels, so that a wide gap is provided between the blocking member 6 and the mounting base Bse. It is provided so that the blocking member 6 does not collide with the mounting base Bse due to vibration.
However, when the inductive switch of the present invention is used in a place where it is not necessary to consider the influence of vibration, the blocking member 6 of the inductive switch 1 is formed as follows. That is, as shown in FIG. 5, the blocking member 8 is set to have a longer length extending downward from the main body 8 a so as to cover the first core member 2 more widely than the main body 6 a of the blocking member 6. When such a blocking member 8 is used, the inductive switch 1 is further improved in the effect of blocking external contact with the first core member 2 and the second core member 5 and becomes more reliable.
[0021]
【The invention's effect】
According to the first and second aspects of the present invention, it is possible to provide an inductive switch that blocks external contact with the first or second core member and has improved reliability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view showing a first embodiment of an inductive switch of the present invention.
2 is a cross-sectional front view showing the inductive switch of FIG. 1 together with a modified example of the blocking member.
FIG. 3 is a cross-sectional front view showing the inductive switch of FIG. 1 together with another modified example of the blocking member.
FIG. 4 is a sectional front view showing a second embodiment of the inductive switch of the present invention.
FIG. 5 is a cross-sectional front view showing a modification of the inductive switch shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inductive switch 2 1st core member 2a Coil 3 Bobbin 4 Bus bar 5 2nd core member 6 Shut off member 7 Bolt 8 Shut off member 10, 12 Shut off member 20 Inductive switch 21 1st core member 22 Bobbin 23 Bus bar 25 2nd core member 2 Blocking member 27 Bolt Bnt Bonnet (second member)
Bse mounting base (first member)
R Reinforcing rib

Claims (1)

A first core member made of an electrically insulating magnetic material and molded in a ring shape with a coil wound around a coil groove;
A second core member made of an electrically insulating magnetic material, provided so as to be vertically insertable inside the ring shape of the first core member, and forming a magnetic circuit in cooperation with the first core member And
In operation of the second core member to the first core member and away from relatively close inserted or withdrawn, the detecting the relative position of the second core member and the first core member An inductive switch that
A blocking member that covers the periphery of the first core member and the second core member, is formed in a cap shape to block contact from the outside, and the second core member is attached to the inside of the cap shape. An inductive switch is provided.

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