JPH049657Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cover body of a magnetic sensor device incorporated into, for example, a banknote validating machine or an automatic ticket gate.

BACKGROUND ART AND PROBLEMS As is well known, banknote validators, automatic ticket gates, and the like incorporate magnetic sensor devices that detect banknotes and tickets coated with magnetic paint or the like.

In such magnetic sensor devices, since objects to be detected such as banknotes slide at a fairly high speed on the surface of the cover body, a cover body made of a magnetic metal is generally used. Among these, those made of beryllium copper are often used.

Among non-magnetic metals, beryllium copper is relatively flexible and has good drawing properties with a mold, so it has a large inner height that can accommodate device components such as magnetoresistive elements and permanent magnets. It has the advantage that the cover body can be easily manufactured by deep drawing, but on the other hand, it has poor wear resistance and may wear out in a relatively short period of time due to abrasion with the detected object. There is a problem.

In order to solve this problem, hard chrome plating is used on the surface of the beryllium copper cover body, but since such hard chromium has a small amount of magnetism, the sensor is not interfered with by this magnetism. The plating film must be formed thinly, and therefore, it is difficult to expect a significant improvement in wear resistance of a cover body subjected to such plating treatment.

For this reason, cover bodies made of highly hard nonmagnetic metals such as tungsten and molybdenum, which have excellent wear resistance, are already in use. However, since such high-hardness non-magnetic metal cannot be deep-drawn, even if it is drawn, a metal cover 10 similar to a flat plate with a small internal height as shown in FIG.
Therefore, the four edges of the metal cover 100 are embedded in a synthetic resin frame 101 to form a cover body 102 with a composite structure, and a magnetic resistance element 103, a permanent magnet 104, etc. are placed inside the cover body 102. Contains component parts. However, when the four side walls of the cover body 102 are formed by the synthetic resin frame 101 in this way, it is difficult to shield the device from static electricity on all sides, which makes it susceptible to static electricity damage. There is.

To solve this problem, as shown in FIG. 7A, a high hardness non-magnetic metal plate 105 is punched out and bent along the broken line to form a box-shaped metal cover 106 with a large internal height as shown in FIG. 7B. The four side walls of this metal cover are embedded in a synthetic resin frame 101 to form a composite structure cover body 107 as shown in FIG. It is conceivable that the side walls provide electrostatic shielding on all sides. However, the metal cover 106 formed by bending in this way has four corner parts 108 that are cut and sharp. There is a risk of getting caught. Moreover, if the four corner sections 108 are cut, there is a risk that moisture and dust may enter there and have an adverse effect, which may lead to problems such as the need for a troublesome process such as sealing the corner sections 108 from the back side. be.

This idea was made in view of the actual situation,
The purpose is to provide a cover body for a magnetic sensor device that is satisfactory in all aspects such as wear resistance, electrostatic shielding properties, and workability.

Means for Solving the Problems In order to achieve the above object, the present invention includes a box-shaped high-hardness non-magnetic metal cover with a top plate and four side plates, and a box-shaped high-hardness non-magnetic metal cover with the four side plates embedded in the metal cover. The part from the top plate of the metal cover to the upper part of each side plate is a continuous drawn part, and the lower part of each side plate is separated from each other at the side plate joining corners at the four corners. The summary is as follows.

Example Examples will be described below with reference to the drawings.

FIG. 1 is a perspective view of a cover body according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the cover body,
Reference numeral 1 indicates a high hardness non-magnetic metal cover, and reference numeral 2 indicates a synthetic resin frame.

The metal cover 1 is made of a highly hard non-magnetic metal plate made of titanium, tungsten, molybdenum, etc. or a metal plate whose surface has been nitrided, and as shown in FIG. It has a long and narrow box shape with side plates 12, 13, 14, and 15. Among these four side plates, the lower ends of the side plates 12 and 14 on both sides in the width direction are directed outward.
It is bent into a shape, and the side plates L on both sides in the longitudinal direction are
3 and 15 have larger vertical dimensions than the side plates 12 and 14 on both sides in the width direction, and as shown in FIGS. It is configured to protrude further downward.

A major feature of this metal cover 1 is that the portion from the top plate 11 to the upper parts of the four side plates 12, 13, 14, and 15 is drawn to form a smooth convex curve without any cuts as shown in Figure 3. 10, and has a structure in which the lower portions of the side plates 12, 13, 14, and 15 are separated from each other at the four side plate joining corners.

With such a structure, there is no need to form the entire metal cover by deep drawing, and only the drawn part 10 needs to be formed by shallow drawing, so a high hardness non-magnetic metal plate that is difficult to deep draw can be used. Also, the metal cover 1 can be manufactured relatively easily by a method as shown in FIG. 4, for example. That is, the fourth
As shown in FIG.
A high-hardness non-magnetic metal plate 1a with a developed shape provided with a is produced by punching, and this metal plate 1a is placed in a mold to form a portion 11a that will become the top plate and a drawing margin 16a.
At the same time, the lower portions 12a, 13a, 14a, and 15a of each side plate are subjected to shallow drawing.
The metal cover 1 can be obtained by bending it into an L shape as shown in FIG. It is. In that case, the thickness of the high hardness non-magnetic metal plate 1a is 0.12 to 0.05 mm.
It is preferable to select and use a material of a certain degree because the workability will be extremely good.

The metal cover 1 obtained in this way is
~ As shown in Figure 2, the four side walls 12, 13, 1
4 and 15 are synthetic resin frames 2 made by insert molding.
A cover body is constructed in which the upper ends of the top plate 11 and the synthetic resin frame 2 are substantially flush with each other, and the side plates 13 and 15 on both sides in the longitudinal direction protrude downward from the synthetic resin frame 2.

As shown in FIG. 5, the cover body contains a magnetic resistance element 3 and a permanent magnet 4 for supporting and fixing the element, and is further sealed with a casting resin 5 to constitute a magnetic sensor device. Ru. When the device is assembled into a bill validator or the like, one of the side plates 13 and 15 of the metal cover 1 that protrudes downward is connected directly or via a conductive wire 6 to a ground terminal (not shown). When connected in this manner, static electricity generated due to friction when the object to be detected slides on the surface of the cover body is removed, thereby preventing static electricity damage. Note that 7 is a terminal for feeding power to the magnetoresistive element 3 and for taking out an electrostatic signal from the element 3.

Effects of the invention As mentioned above, the metal cover of the cover body of the present invention is made of a highly hard magnetized metal with excellent wear resistance, so even if an object to be detected slides on the surface at a considerably high speed, there is almost no wear. Therefore, it can be used for a long period of time. Moreover, this metal cover is box-shaped, and the four side plates embedded in the synthetic resin frame surround the magnetic sensor device from all sides, so if the metal cover is grounded, it will exhibit an excellent electrostatic shielding effect and cause electrostatic damage. can be satisfactorily prevented. Furthermore, the entire metal cover is not formed seamlessly by deep drawing, but only the drawing parts from the top plate to the upper parts of the four side plates are formed seamlessly by shallow drawing, and each Since the lower parts of the side plates are separated from each other at the four side plate joining corners, even if the plate is a high hardness non-magnetic metal plate that is difficult to deep draw as mentioned above, it is possible to partially shallow draw it. This makes it relatively easy to manufacture. In addition, if the part from the top plate of the metal cover to the upper part of the side plates on all four sides is made into a smooth drawn part without cuts, the object to be detected will not get caught when sliding on the surface of the metal cover. . Furthermore, since the four side plates of this metal cover are embedded in the synthetic resin frame, even if the lower parts of each side plate are separated from each other, the separated parts are completely sealed by the synthetic resin frame. This eliminates the risk of moisture or dust entering from there and causing adverse effects.

As described above, the cover body of the magnetic sensor device of the present invention is fully satisfactory in all respects such as wear resistance, electrostatic shielding property, workability, sliding property of the detected object, and sealing property. Very useful.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a cover body of a magnetic sensor device according to an embodiment of the present invention, FIG. 2 is a vertical sectional view of the cover body, FIG. 3 is a perspective view of a metal cover, and FIG.
Figures A and B are explanatory diagrams of an example of the manufacturing method of a metal cover, Figure 5 is a longitudinal cross-sectional view showing an example of a magnetic sensor device, Figure 6 is a cross-sectional view of a conventional example, and Figures 7 A, B, and C are illustrations of other examples. It is a manufacturing method explanatory diagram of a conventional example. 1...Metal cover, 2...Synthetic resin frame, 10...
... Drawing processing section, 11 ... Top plate, 12, 13, 1
4,15...Side plate.

Claims (1)

[Scope of utility model registration request] It consists of a box-shaped high-hardness non-magnetic metal cover with a top plate and four side plates, and a synthetic resin frame in which the four side plates of this metal cover are embedded. What is claimed is: 1. A cover body for a magnetic sensor device, characterized in that a portion extending to the ?