JP3356486B2 - Magnetic proximity sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a proximity magnetic sensor in which a permanent magnet and a reed switch are combined to form a magnetic circuit.
It is about. It is mainly used for the qualitative and quantitative direct detection of a spherical fluid magnetic substance such as a pachinko ball. It is also used for detecting the movement of a massive magnetic body.
Further, indirect detection is possible in combination with other permanent magnets and magnetic materials.

[0002]

2. Description of the Related Art In a conventional magnetic body proximity sensor, a reed switch and an exciting magnet for magnetizing an object to be detected are provided at a distance from each other so as to sandwich the object.

[0003]

Accordingly, the reed switch and the magnet for excitation are separately mounted in accordance with the respective detection conditions, so that the following problems remain. -It is difficult to integrate and reduce the size. The main detection range is within the range in which the direction of detection of the object to be detected connects the exciting magnet and the reed switch, and is substantially unidirectional. Therefore, the detection range is narrow.・ Sensitivity management cannot be performed at the time of parts shipment. -There is a large restriction on the use location because it takes up space in the installation location. -Installation work is difficult, and the operation greatly depends on the installation situation. -Replacement work requires a lot of man-hours to remove the entire sensor system. -It is difficult to find the cause of the defect after recovery because the system environment of the sensor collapses when recovering the defective product. -The amount of the object passing through the magnetic circuit for detection is large, and a small amount of object cannot be detected.

[0004]

A magnetic proximity sensor according to the present invention comprises a magnetically responsive reed switch, at least one fixed magnet, at least one magnetic responsive adjusting member and a non-magnetic cylindrical member , The fixed magnet is positioned in the longitudinal direction of the reed switch, and the magnetic reaction adjusting member, the reed switch and the fixed magnet are non-magnetic cylindrical parts.
It is obtained by surrounding with a material .

[0005]

In the magnetic proximity sensor according to the present invention, magnets for excitation are arranged adjacent to each other on the same axis in the longitudinal direction of the reed switch so that both poles come in the same direction in the longitudinal direction. Thereby, it becomes the rod shape with which the shape was integrated. In addition, the reed switch reacts magnetically even if the magnetic material approaches any of a wide range of 360 ° surrounding the rod, so that the detection range is wide. Since it is rod-shaped, it does not easily hinder movement even when it directly hits the magnetic material. Further, since it is hard to inhibit, it can be inserted into the magnetic body.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a non-magnetic cylindrical member, 3 is a columnar permanent magnet, 5 is a reed switch, 7 is a glass tube,
9 is a contact point, 11 is a heat-resistant wire, 13 is an insulating heat-resistant synthetic resin,
15 is a lead wire, 17 is a magnetic plate, and 19 is one of magnetic reaction control members.
One is a magnetic reaction control magnet, 21 is a rubber ring, 23 is an iron ball, 27 is a terminal, 29 is a mounting member, and 25 is a mounting base.

The main structure of the present invention will be described below. -The non-magnetic cylindrical member 1 is made of an aluminum tube, and one end is opened and the other end is closed. The columnar permanent magnet 3 is inserted into a substantially closed end of the non-magnetic cylindrical member 1, and after adjustment, is fixed by an adhesive. The reed switch 5 is inserted along the longitudinal direction of the non-magnetic cylindrical member 1 almost to the center of the non-magnetic cylindrical member 1, and the both ends are sandwiched between two insulating heat-resistant synthetic resins 13 to form the non-magnetic cylindrical member. It is fixed in member 1. -The lead wire 15 of the reed switch 5 is bent into a U-shape, extended to the vicinity of the contact 9 of the reed switch 5, and connected to the heat-resistant wire 11 by solder. The heat-resistant wire 11 and the lead 15 at the other end of the reed switch 5 pass through the center of the insulating heat-resistant synthetic resin 13 and communicate with the opening side of the non-magnetic cylindrical member 1. The heat-resistant electric wire 11 near the opening is fixed by coating. The magnetic plate 17 is attached to the approximate center of the reed switch 5 after being adjusted with an adhesive.・
The shape of the magnetic response adjusting magnet 19, which is one of the magnetic response adjusting members, is cylindrical. The installation position is near one end of the reed switch 5 and is provided on the opposite side of the fixed magnet 3. The magnetic polarity is set so as to form a mirror image with the fixed magnet 3. In other words, the lead switches of both the fixed magnet 3 and the magnetic reaction adjusting magnet 19
The 5th side is the S pole. The fixing means is inserted into and fixed to the non-magnetic cylindrical member 1 so that the relative distance to the reed switch 5 can be finely adjusted. A rubber ring 21 is inserted into the opening end of the non-magnetic cylindrical member 1 so that the rubber ring 21 can be connected to various mounting bases 25 having a U-shaped or o-shaped hole. Is configured.

The sensitivity of the magnetic proximity sensor according to the present invention having the above-described structure is adjusted by the following method.・ Adjust the distance between the reed switch 5 and the cylindrical permanent magnet 3 for excitation. A lead wire 15 made of a magnetic material at both ends of the reed switch 5 is bent in a U-shaped antisymmetric manner in parallel with the glass tube 7 to increase or decrease the amount of the lead wire along the glass tube.・ The sensitivity of the reed switch is adjusted by attaching an appropriate amount of a separately prepared magnetic plate 17 with a small residual magnetization along the glass tube of the reed switch 5. If necessary, the sensitivity of the reed switch can be adjusted by providing, for example, a cylindrical magnetic body to the outside of the non-magnetic cylindrical member 1, and in this case, it can be adjusted from the outside after the main body is completed. There are advantages. -The distance between the reed switches 5 is changed by sliding the magnetic reaction adjusting magnet 19 which is inserted and fixed inside the non-magnetic cylindrical member 1. Since the reed switch 5 side of both the fixed magnet 3 and the magnetic reaction adjusting magnet 19 has the same polarity, a zero magnetic pole area is created between these magnets, where the magnetism is eliminated. Adjust so that this zero magnetic pole area is at the center of the reed switch 5. With this adjustment, the reed switch 5 does not work if there is no magnetic material outside, and the reed switch 5 does not work until the magnetic material approaches the outside.
Will work. As an installation method of the present invention, it is effective and simple means to provide a rubber ring near the installation location and insert and fix the cylindrical outer peripheral portion 5 of the present invention to this ring. By changing the depth, the distance to the object can be easily changed, and as a result, the sensitivity can be adjusted.

FIGS. 2 to 7 are magnetic force diagrams showing how the magnetic body proximity sensor of the present invention operates on an external magnetic body (in this case, an iron ball 23). Magnetically unrelated members have been removed. FIG. 2 shows the case where the iron ball 23 is not present, and the magnetic lines of force from the columnar permanent magnet 3 are magnetically attracted to the lead wire 15 and the magnetic plate 17 (the line of magnetic force flows toward the lower magnetic resistance).
As a result, few lines of magnetic force pass through the contact portion 9 in the reed switch 5, and the contact portion 9 is turned off without contact. FIG. 3 shows a state in which the iron ball 23 which is a magnetic material and has the same configuration as that of FIG. 2 is approached, and since the magnetic force lines are entirely biased toward the reed switch 5, the magnetic force attracting action of the lead wire 15 and the magnetic plate 17 is Although still present, the movement of the magnetic field lines exceeding this action occurs, and as a result, the magnetic field lines passing through the reed switch 5 increase and the magnetic field lines passing between the contact portions 9 increase, and the contact portions 9 come into contact and the reed switch 5 It turns on. FIG. 4 is a magnetic force diagram with the lead wire 15 and the magnetic plate 17 removed. The lead switch 5 always operates only by the magnetic force of its own fixed magnet 3 irrespective of the presence or absence of a magnetic object to be detected. I have. FIG. 5 shows magnetic lines of force in which the magnetic reaction adjusting magnet 19 is provided in the state of FIG. The magnetic field lines do not pass near the center of the reed switch 5. FIG. 6 shows a state in which the iron ball 23 which is a magnetic body approaches in the state of FIG. When the iron ball 23 approaches, the balance between the fixed magnet 3 and the magnetic reaction adjusting magnet 19 is lost, and a magnetic force is generated between the reed switches 5, and as a result, the reed switch 5 is operating. FIG. 7 has the same configuration as FIG. 2, but the installation means is provided so that the fixed magnet 3 faces upward. The iron balls 23, which are magnetic materials, naturally gather near the mounting base 25. Even in this situation, the magnetic field lines are biased toward the reed switch 5 side as a whole, so that although the magnetic force attracting action of the lead wire 15 and the magnetic plate 17 still exists, the magnetic field lines move beyond this action, and as a result, the reed switch 5 The number of magnetic lines of force passing through the inside increases, and the number of magnetic lines of force passing between the contact portions 9 also increases.

Next, an example of a method of using the magnetic proximity sensor according to the present invention will be described below with reference to FIG. The cylindrical permanent magnet 3 is positioned downward so that the flow of the pachinko balls is not obstructed near the edge of the back plate tank of the pachinko machine by the mounting member 29 which can insert and mount the outer peripheral portion of the cylinder of the magnetic body proximity sensor. Attach (A state). On the other hand, both terminals 27 of the magnetic sensor are connected to the pachinko ball flow control computer C. In addition, the magnetic substance proximity sensor of the present invention is installed near the falling pipe of the pachinko ball along the pipe (B
State), and used to detect whether a pachinko ball is passing through the pipe as scheduled.

It can be used as a door switch by attaching it to the inside of a glass frame of a pachinko machine as required and detecting the presence or absence of metal in the door frame when opening and closing the door. Although the present invention is characterized by the integration, it is also possible to narrow the detection range by attaching an auxiliary magnet separately to the outer peripheral part as needed.

On the other hand, a lead 15 as a magnetic member and a magnetic plate
17 and the magnetic ring 19 can be freely designed to be used alone or as a combination of these. Further, the magnetic polarity of the magnetic reaction adjusting magnet 19 can be provided so as to be in the same direction as the fixed magnet 3. In this case, the two magnets react with each other to a magnetic substance which is a farther object due to a synergistic effect. Also, the reed switch 5 can be freely set so as to form an off state at the time of detection and an on state at the time of non-detection.

[0013]

The present invention has the following effects. Since the external shape is formed as a bar, it can be easily attached to and detached from the detection point.・ The detection sensitivity can be set in advance at the time of manufacture. (Conventionally, since the positional relationship between the reed switch and the magnet for excitation at the installation location is uncertain, the detection sensitivity was only performed after installation.) -Since the measurement can be performed by inserting the rod-shaped main body into the flow of the magnetic material having the flow such as the iron ball, the detection can be performed close to the object to be detected, so that the detection error is small and the flow is not hindered. For example, when a versatile rubber ring 21 is used for the attachment / detachment portion, the attachment / detachment structure with the attachment base 25 can be simplified. When the sensitivity adjusting members (15, 17) are provided near the reed switch 5, fine adjustment during manufacturing can be performed without changing the positional relationship between the fixed magnet 3 and the reed switch 5 according to the detection purpose. When the sensitivity is adjusted by the lead wire 15, the number of parts is small and the cost is advantageous. A magnetic response adjusting magnet 19 is provided as a substitute for the sensitivity adjusting member (15, 17) on the opposite side of the fixed magnet 3 with reference to the reed switch 5, and the amount of magnetic force passing through the reed switch 5 is reduced by magnetic repulsion. When the adjustment is made so that the magnetic material is approached from outside, magnetic detection with high sensitivity becomes possible for a magnetic substance approached from the outside.

[Brief description of the drawings]

FIG. 1 is a partial sectional perspective view showing an embodiment of the present invention.

FIG. 2 is a magnetic force diagram when a magnetic substance to be detected does not exist.

FIG. 3 is a magnetic force diagram when a magnetic body to be detected exists in the same configuration of FIG. 2;

FIG. 4 is a magnetic force diagram with the lead wire 15 and the magnetic plate 17 removed.

FIG. 5 is a magnetic field diagram in a state where a magnetic reaction adjusting magnet 19 is provided in the state of FIG.

FIG. 6 is a magnetic field diagram showing a state in which a detected magnetic body approaches in the state of FIG. 5;

FIG. 7 is a magnetic force diagram of the same configuration as that of FIG. 2 but in a state where the installation direction is reversed and the magnetic body to be detected is brought closer.

FIG. 8 is a layout diagram illustrating an example of a method of using the magnetic proximity sensor of the present invention.

[Explanation of symbols]

 In Figure 1, 1 ‥‥ Non-magnetic cylindrical member 3 ‥‥ Cylindrical permanent magnet 5 ‥‥ Reed switch 7 ‥‥ Glass tube 9 ‥‥ Contact 11 ‥‥ Heat resistant wire 13 ‥‥ Insulation heat resistant synthetic resin 15 ‥‥ Lead wire 17 ‥‥ Magnetic plate 19 ‥‥ Magnetic ring 21 ‥‥ Rubber ring 23 ‥‥ Iron ball 25 ‥‥ Mounting base 27 ‥‥ Terminal 29 ‥‥ Mounting member C ... Pachinko ball flow control computer

Claims (4)

(57) [Claims] 1. Both ends of a lead wire (15) made of a magnetic material
A read switch (5) which reacts to the magnetic preparation for, and at least one fixed magnet (3) comprises at least one magnetically responsive adjustment members and non-magnetic cylindrical member (1), longitudinal of the lead switch (5) The fixed magnet (3) is positioned coaxially in the direction, and the magnetic reaction control member, reed switch (5) and fixed magnet (3) are surrounded by a nonmagnetic cylindrical member (1) and
The shape is formed as a bar, and a magnetic field of 360 ° surrounding the bar is formed.
A magnetic body proximity sensor that detects sexual bodies . 2. The reed switch according to claim 2, wherein the magnetic reaction control member is a reed switch.
It is composed of magnetic members (15, 17) positioned near (5),
The magnetic proximity sensor according to claim 1, wherein the reed switch (5) is not operated by a magnetic reaction of only the fixed magnet (3). 3. A magnetic reaction adjusting magnet (1) provided near a reed switch (5) on the opposite side of the fixed magnet (3).
9), the magnetic polarity of the magnetic reaction adjusting magnet (19) is fixed magnet
2. The magnetic proximity sensor according to claim 1, wherein the magnetic pole of the magnetic pole of (3) is provided with a magnetic pole, so that the reed switch (5) does not operate due to the magnetic reaction of only the fixed magnet (3). 4. The magnetic proximity sensor according to claim 2, wherein the magnetic member is formed by a magnetic lead wire (15) folded back along the lead switch (5).