JPH07280821A - Magnet fixing structure for speedometer of bicycle - Google Patents

Abstract

PURPOSE:To fix a magnet easily to any type of wheel without increasing the running resistance and without sacrifice of the appearance. CONSTITUTION:Powder of a rare earth element, e.g. neodymium, is formed into a sheet to produce a magnet 102 which is then laminated with a plastic film. It is then applied to a rim 108 along with a logotype of manufacturer and a seal 110 indicating the quality of wheel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for mounting a magnet of a bicycle speedometer by so-called retrofitting.

[0002]

2. Description of the Related Art In recent years, bicycles have been attracting new attention in addition to the use as so-called foot of life, for leisure, as a means for promoting health, and as a kind of sports.

[0003] When using a bicycle for such a purpose, knowing how fast the driver is currently traveling is to make the leisure more enjoyable and a guideline for health promotion. Will be provided. When the bicycle is used as a sport or for training for other sports, it is essential to know the running speed.

In view of such a background, in recent years, an increasing number of users are installing a so-called speedometer on their bicycles.

[0005] Since a bicycle speedometer is not legally required to be installed, a user generally purchases an option set device or a device sold separately as a service at the user's hand or at a bicycle shop. Depending on the vehicle, it is generally installed at the time of assembling the wheel or attached by retrofitting.

In principle, a speedometer is constructed by mounting a magnet on the wheel side, arranging a magnetic sensor on the body side, and counting the number of times the magnet approaches the magnetic sensor per unit time. .

When this magnet is attached later, it is specifically performed as shown in FIG. 5, for example. That is, the magnet 1 is mounted on the wheel 2 side by attaching the locking member 4 made of plastic or metal incorporating the hard magnetic material (magnet body) 3 such as ferrite to the two members 4
Disassembled into A and 4B, a female screw 5 is formed on one side and a male screw 6 is formed on the other side, and a portion near the rim 8 of the spoke 7 of the wheel 2 is sandwiched by these two members 4A and 4B. .

Further, as shown in FIG. 6, the spoke 1
A configuration in which the magnet 11 is attached so as to straddle the two spokes 17 at the intersection of the seven and seventeen is also widely adopted. Also in this case,
The locking member 14 incorporating the magnet body 13 is substantially divided into two members 14A and 14B, and is attached to the wheel 12 by screws 15 and 16 while sandwiching the spokes 17 and 17.

Further, as shown in FIG. 7, a resin locking member 24A incorporating the magnet body 23 is fitted into the spoke 27 by utilizing the elasticity of the resin, and the fitted portion is A configuration has also been proposed in which the wheel 22 is locked by being tightened from the outside with a metal locking member 24B.

As is apparent from the description of FIGS. 5 to 7, the conventional magnets 1, 11, 21 are attached to the wheels 2, 12, 22 all in a (substantially) disassembled locking member. The hard magnet bodies 3, 13, and 23 are incorporated into one of the four 4A, 14A, and 24A, and the two locking members 4A and 14
They are common in that they are attached to the spokes 7, 17, 27 of the wheels 2, 12, 22 by A, 24A and 4B, 14B, 24B.

[0011]

However, since all of these conventional magnet mounting structures are mounted on the spokes of a bicycle, there is a strong image that foreign matter is mounted on the wheels, and the quality of the appearance deteriorates. There was an unavoidable problem.

In addition, since the foreign matter goes around with the wheel while traveling, not only the appearance is further impaired, but also depending on the shape and size of the locking member of the magnet, this rotation causes air flow on both sides of the wheel. There is a problem in that running resistance increases because of disturbances in the vehicle.

This problem of increased running resistance is especially noticeable by many users who use bicycles for sports, and it is desirable to attach a magnet so as not to increase running resistance as much as possible. Was there.

On the other hand, in recent years, for example, in bicycles for leisure purposes, the unique design is given priority, and the rim is not supported by a large number of so-called wire-shaped spokes.
Wheels, such as aluminum wheels for automobiles, in which a rim is supported by a wide rod having a width of several cm are commercially available. Further, a wheel having a structure in which the outer surface of the rim is entirely covered is commercially available. In the case of the wheel having such a special structure, the conventional mounting structure has a problem that the magnet itself cannot be mounted.

The present invention has been made in view of the above conventional problems, and does not impair the appearance of the bicycle.
It is also an object of the present invention to allow the magnet of the speedometer to be attached to the wheels of various shapes with almost no increase in running resistance.

[0016]

According to the present invention, a magnet is mounted on the wheel side of a bicycle, a magnetic sensor is arranged on the body side, and the number of times the magnet approaches the magnetic sensor per unit time is counted. In a magnet mounting structure for a bicycle speedometer that measures the speed of, the magnet is formed into an elastic sheet using magnetic powder of rare earth, and a coating process is applied to this sheet, The above problem is solved by adopting a structure in which the device is attached by being attached to a part thereof.

[0017]

In the present invention, in order to solve the above-mentioned problems all at once, the conventional magnet mounting structure has been drastically reviewed. That is, a structure is adopted in which the magnet is formed in an elastic sheet shape, and the sheet-shaped magnet is attached to a part of the wheel, for example, a rim by attaching.

In this case, the sheet-like shape tends to reduce the magnetic flux density generated by the magnet.
In the present invention, this is solved by using a rare earth magnetic powder capable of obtaining a strong magnetic force as the material of the magnet. As the rare earth magnetic powder, for example, so-called neo dimagnet powder using Nd-FB powder can be adopted. To reduce the magnetic flux density, a method of electrically increasing the sensitivity on the magnetic sensor side may be considered, but since the bicycle is used outdoors, the increased sensitivity may cause foreign matter to adhere. Considering that it is likely to be affected by disturbance, simply increasing the sensitivity on the magnetic sensor side is not a desirable measure.

Further, in the present invention, the seat is coated in consideration of the fact that the bicycle is used outdoors. The structure of applying this coating is not only for the protection of the appearance, but since the present invention uses the rare earth magnetic powder as the magnetic material of the magnet,
This is also adopted to obtain the action of eliminating the drawback that it is easily oxidized. The coating process here includes the concept of so-called laminating process.

According to the present invention, since the magnet is formed into an elastic sheet and is simply attached to the rim of the wheel or the like, the appearance is not impaired and the running resistance is not increased. . Further, it can be installed on a spokeless tire which has been prioritized in design in recent years without any trouble.

Further, since the magnet is in the form of a sheet, and there is no feeling of foreign matter adhering and running resistance does not increase, the degree of freedom in the method of sticking and the method of counting the number of times of approach with the magnetic sensor is significantly increased, as will be described later. Therefore, it is possible to obtain a more accurate speed measurement.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a magnet 1 to which the present invention is applied.
FIG. 10 is a partial front view of 02 attached to the rim 108 of the wheel 104. FIG. 2 is a sectional view taken along the line II-II. The magnet 102 is a square or a rectangle with a side of 1 cm to 2 cm, or a so-called neodymium magnet (rare earth Nd-F-.
It is formed in a sheet shape by a rubber mixed with a magnet having B powder as a magnetic material.

As is well known, the neo dimagnet can obtain an extremely strong magnetic flux even in a small amount, and is therefore the most suitable magnetic material for carrying out the present invention.

This sheet-shaped magnet 102
Is laminated and the surface thereof is covered with the plastic film 106. Therefore, it is possible to effectively prevent the magnet 102 from being oxidized by being used outdoors.

In this embodiment, when the sheet-shaped and laminated magnet 102 is attached to the rim 108 with the seal 110 displaying the manufacturer's logo, the feature of the wheel, or the design preferred by the user, etc. I try to paste it together.

Therefore, since it is not necessary to prepare an adhesive or the like for attaching the magnet 102 itself, it is possible to minimize the time and effort of the attachment, and the sticker 110 having the logo of the manufacturer is attached. Since it is completely covered with the magnet, it is possible to make a state in which it is almost unknown that the magnet 102 is attached. Further, since it is different from the case where the magnet is attached to the spoke 112 as in the conventional case, the magnet does not noticeably turn around while running.

Further, since the presence of the seal 104 can further reduce the unevenness due to the presence of the magnet 102, the running resistance can be reduced accordingly.

In the above embodiment, the seal 110 on which the manufacturer's logo or the like is displayed is attached to the wheel rim 10.
Although the magnet 102 was attached together when it is attached to the No. 8, in the present invention, it is natural that the magnet 102 itself may be provided with release paper and attached directly to the rim 108.

Needless to say, it may be attached using an adhesive.

Next, FIG. 3 shows another embodiment of the present invention.

In this embodiment, the magnet according to the present invention is very easy to attach, and the fact that the magnet is inconspicuously attached is positively contributed to improve the detection accuracy. That is, in the embodiment shown in FIG. 3, a plurality (three in the illustrated example) of the magnets 102 according to the present invention are attached at a predetermined interval L.

As a result, every time the wheel makes one revolution on the magnetic sensor (not shown) side, the approach of the magnet 102 is detected three times within an extremely short time (a magnetic flux of a specific predetermined value (threshold value) or more is detected). Will be done. Therefore, the magnetic sensor side can be configured to recognize that the wheel makes one rotation only when the approach of the magnet 102 is detected three times in a row in a short time.

In general, the detected value exceeds a predetermined value due to the influence of disturbance because it is a one-time event and has no regularity. Therefore, even if the gain on the magnetic sensor side is increased by such a configuration, the detected value exceeds the predetermined value. Even if the value of is made small), it becomes possible to very accurately discriminate between the false detection due to the disturbance and the correct detection due to the approach of the magnet 102. As a result,
The detection accuracy can be significantly improved.

Further, as shown in FIG. 4, in the present invention, by utilizing the fact that the magnet is a sheet, the magnet 102A is formed into a strip-shaped sheet of, for example, several cm (or more). You can also As a result, on the magnetic sensor side, information whose detected value exceeds the predetermined value is obtained continuously for a predetermined time. Generally, the detected value exceeds the predetermined value for a moment due to the influence of the disturbance caused by the foreign matter, and thus the disturbance is determined by the condition that the time when the value exceeds the predetermined value is continuously detected for the predetermined time. It is possible to reliably distinguish between the detection of approaching the magnet and the detection of approaching the magnet.

It is easy to electrically increase the gain on the magnetic sensor side (lower the predetermined value for approach detection).
However, this increases the possibility of erroneous detection due to foreign matter, which makes it difficult to distinguish between actual magnet detection and erroneous detection due to foreign matter. However, in the present invention, the magnet is formed in a sheet shape. Therefore, it becomes extremely easy to attach multiple sheets or attach a long sheet in this way, and it is very accurate only by giving a slight discriminating function to the method of judging the detection value on the magnetic sensor side. It will be possible to detect. It goes without saying that an embodiment combining FIG. 3 and FIG. 4 can also be adopted.

[0037]

As described above, according to the present invention, the magnet can be easily attached to any wheel without impairing the appearance quality of the bicycle wheel and without increasing the running resistance. It is possible to obtain an excellent effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a partial front view in which a magnet to which the present invention is applied is attached to a wheel rim.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a front view showing a stuck state of a magnet showing another embodiment of the present invention.

FIG. 4 is a front view showing still another pasted state.

FIG. 5 is an exploded perspective view for explaining a conventional magnet mounting structure.

FIG. 6 is a partial perspective view showing another conventional magnet mounting structure.

FIG. 7 is an exploded perspective view showing still another example of a conventional magnet mounting structure.

[Explanation of symbols]

 102, 102A ... Magnet 104 ... Wheel 106 ... Plastic film (laminated part) 108 ... Rim 110 ... Seal

Claims (1)

[Claims] 1. A bicycle is mounted on a wheel side of a bicycle, a magnetic sensor is arranged on a body side, and the speed of the bicycle is measured by counting the number of times the magnet approaches the magnetic sensor per unit time. In a magnet mounting structure for a bicycle speedometer, the magnet is formed into an elastic sheet using magnetic powder of rare earth, and a coating process is applied to the sheet, and the sheet is attached to a part of the wheel. A magnet mounting structure for a bicycle speedometer, which is characterized by being mounted.