JPS6038257A - Device for stabilizing tack strength - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an adhesive force stabilizing device, in particular between a wheel and a rail, or between a pulley and a rope, which transfers driving force or The present invention relates to a device that stabilizes adhesive force when transmitting braking force.

[Background of the invention]

2. Description of the Related Art Mechanical devices that transmit force in the direction of a friction surface made of a magnetic material are generally widely used.

For example, in a railway vehicle, this corresponds to the wheels and rails, and in an elevator, force is transmitted between the pulley and the rope. This kind of force is hereinafter referred to as adhesive force.

The maximum adhesive force F that can be transmitted in such a device is
The force applied perpendicularly to the friction surface W1 is generally expressed as follows, where μ is the friction coefficient of the friction surface.

F=μW(1) and ＼The force W is generally a constant value determined by the device, but the friction coefficient μ changes significantly depending on the surface condition of the friction surface, sliding speed, etc. In particular, when the friction surface is dry, the friction coefficient μ is maximum, but when the friction surface is wet,
It is known that the coefficient of friction μ decreases rapidly when oil is attached.

As a result, there is a problem in that, for example, the adhesive performance of a railway vehicle is significantly lower when it is wet or when oil is attached to the rail compared to when it is dry in sunny weather.

In order to improve this problem, methods such as spreading sand on the rail surface or spraying plasma onto the rail surface to clean it are known, but they are not always effective. No, no.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art described above, an object of the present invention is to provide a device that can stabilize adhesive force by stabilizing the coefficient of friction μ.

[Summary of the invention]

In the present invention, when a magnetic field is applied to a friction surface made of a magnetic material,
The adhesive force is stabilized by utilizing the property that the coefficient of friction μ is stabilized regardless of the surface condition of the friction surface.

The above property is a new fact that has not been known until now,
This was first discovered experimentally by the inventors. Figure 1 shows its real number device, where A is an iron plate (88
41 material), B is an iron cylinder placed on iron plate A, C is cylinder B
The excitation coil is wound around the circumference of the cylinder, W is the force applied from cylinder B to iron plate A at right angles to the contact surface between cylinder B and iron plate A, and F is the force required to make cylinder B slide parallel to the contact surface. It is power.

The cylinder B and the excitation coil C form an electromagnet, and when the excitation coil C is excited, the electromagnet generates a magnetic attraction force that attracts the iron plate A. Therefore, the force W is the combination of the gravity applied to the electromagnet and the magnetic attraction force. It becomes peace.

In the apparatus shown in Fig. 1, the current of the excitation coil was varied in three cases: when the contact surface between the cylinder B and the iron plate A was dry, when it was wet with water, and when it was wet with oil.
The forces W and F were measured, and the friction coefficient μ was determined from equation (1) as μ=F/W (2), as shown in Figure 2.

When the multi-excitation coil current is increased, that is, when the magnetic field acting on the friction surface is strengthened, the friction coefficient μ converges to a constant value regardless of the type of inclusions on the friction surface, that is, regardless of the surface condition. A certain benevolence is recognized.

The physical explanation of this property is limited to speculation at present, but as the magnetic field becomes stronger, the magnetic attraction force also becomes stronger, so water, oil, etc. that were present on the friction surface are removed, and the cylinder is formed. This seems to be because there are more opportunities for the magnetic metals of B and iron plate A to come into direct contact with each other.

[Embodiments of the invention]

An embodiment of the present invention will be described below.

FIG. 3 shows an embodiment of the present invention, in which 1 is an iron wheel, 2 is a rail, 3 and 3I are electromagnetic cores, and 4.4' is an electromagnetic excitation coil. Iron core 3 and coil 4, iron core 3' and coil 4
′ constitutes an electromagnet, and its arrangement is similar to wheel 1.
A gap is placed between the rail 2 and the rail 2 so that the rail 2 can be held. (Although the holding mechanism is not shown, it may be held in the same way on the truck frame or the like where the bearing that supports the shaft of the wheel l is held.

Same below. ) In this way, the wheel 1 and the rail 2 will constitute a magnetic path for the two electromagnets, and by appropriately selecting the polarity of the excitation current flowing through the coil 4゜4/, the magnetic flux generated by the electromagnet will be The contact surface between the wheel 1 and the rail 2 as shown by the broken line,
In other words, since it passes through the friction surface 41, the friction coefficient μ is stabilized, and therefore the adhesive force is also stabilized. expresses the same meaning, but the arrangement is slightly different from that in Figure 3. 3'' is a part of the iron core. In this example, by exciting the rail 4.4 with an appropriate polarity, the magnetic flux will spread across the contact surface between the rail 1 and the rail 2 as shown by the broken line. As it passes through the core, the adhesion can be stabilized.As is clear from the figure, the iron core 3.3' needs to have a very special shape in Fig. 3, whereas in the embodiment shown in Fig. 4, it has a rectangular shape. It can be realized by a combination of and has the characteristic of being easy to manufacture.

In both the embodiments of FIGS. 3 and 4, the electromagnet, wheels, and rails constitute a closed magnetic path that includes a friction surface.
It also has the effect of firmly adhering the wheels to the rail, and is also effective in preventing derailment.

tfc, Conventionally, a method has been proposed in which an electromagnet facing the rail is attached to the bogie frame at a position different from the friction surface between the wheel and the rail, and is unrelated to the magnetic circuit, with the aim of increasing the force W. (Japanese Patent Publication No. 47-48924), however, in addition to stabilizing the friction coefficient μ, the present invention also has the advantage of increasing the maximum adhesive force itself since the force W is also increased by the magnetic attraction force.

In addition, although the example using an electromagnet was shown above, the same effect can be obtained even if a permanent magnet is used.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to stabilize the adhesive performance of a mechanical device that transmits adhesive force in the direction of the surface through a friction surface made of a magnetic material, such as a railway vehicle, and to put it into practical use. The above effect is significant.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of an experimental device for experimentally clarifying the fundamental properties underlying the present invention, Figure 2 is a diagram showing the fundamental properties, and Figure 3 is a diagram showing the principle of the present invention applied to railway wheels. FIG. 4 is a side view showing another embodiment of the present invention. 1... Iron wheel, 2... Rail, a, a/, a//...
...Electromagnetic Figure 1 C

Claims (1)

[Claims] 1. An adhesive force stabilizing device comprising a pair of magnetic bodies that transmit adhesive force to each other via a friction surface, and a magnet whose magnetic path includes the friction surface of the magnetic body.