JPS5943322B2 - Slider for increasing adhesion on wheel treads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slider for increasing the adhesion of a wheel tread, and in particular to an improved material.

Railway vehicles that utilize the adhesion force (frictional force) between wheels and rails have lower adhesion force than automobiles etc. that use rubber tires, so this is strengthened to prevent wheel slipping and skidding.I):
, it is necessary to aim for.

To this end, locomotives have conventionally adopted a method of sprinkling sand between the wheels and the rails when the wheels are spinning or sliding, and in high-speed trains such as the Shinkansen and some diesel trains, a method has been used to spread sand between the wheels that rotate when the brakes are applied. An adhesive slider made of resin or sintered metal material is slid on the tread surface to clean rust, oil, and foreign matter from the wheel tread surface, and remove wear powder from the slider between the wheel and the rail. The adhesive force is increased by interposing the adhesive.

However, the sand scattering method cannot be said to be a preferable method because it consumes a large amount of sand, resulting in a shortage of sand, and it is also expected that vehicles will be operated in special environments where sand scattering should be avoided.

Furthermore, the method of sliding the sliders of microwave ovens, etc. does not have the same or better adhesive force enhancement effect than sand scattering, so it is not yet satisfactory for railway vehicles that require high speeds. In order to prevent accidents and ensure safety, it is desired to improve the adhesive force enhancement effect.

The present invention has been made in view of the above circumstances, and its main purpose is to provide a slider for a wheel tread that has a significantly improved adhesive force enhancement effect.

Still another object of the present invention is to provide a wheel tread slider that can be effectively applied to high-speed vehicles in place of the sand scattering method.

The adhesive increasing slider of the present invention is characterized by being made of a porous ceramic body, and is of a type in which it is constantly pressed against the tread surface of a wheel with a braking force or a pressing force while driving, or a type in which the slider is kept in pressure contact with a wheel tread while driving, or a type in which the slider is pressed with a pressing force that is not limited to a braking force. This applies to any type of wheel tread sliding device that is brought into pressure contact with the wheel tread only when special operation is required.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 shows an example of a wheel tread sliding device to which the present invention is applied, in which an adhesive increasing slider 4 fixed to a mounting body 3 is pressed against the tread of a wheel 2 attached to an axle 1. It shows.

The mounting body 3 is pivotally attached to a support rod 6 by a shaft 5, and although the support rod 6 is not shown, it is rotatably hung at a predetermined position on the vehicle underframe, and is attached to the tread of the wheel 2 when necessary. Apply pressure.

In the case where the slider 4 is brought into pressure contact with the tread of the wheel 2 only when the brake is applied, the slider 4 is kept in standby at a position where it does not normally come into contact with the tread surface of the wheel 2 when the brake is applied, and is interlocked with the brake shoe when the brake is applied. A well-known mechanism for moving the slider 4 to the pressure contact position is employed.

In the present invention, it is important to use a porous ceramic body as the material for the slider 4.

As the ceramic material, it is possible to use either an oxide type such as alumina or a non-oxide type such as silicon nitride or silicon carbide, but a normal dense ceramic body has a water absorption coefficient of 5 or less. , has very good wear resistance,
It is excluded from the material of the slider of the present invention because it conversely abrades the wheel tread surface during sliding.

Therefore, in the present invention, a porous ceramic body, that is, a ceramic body having a water absorption rate of 5% or more, preferably 20% to 30%, is used.

As a result, when the slider 4 slides against the wheel tread, the slider itself wears out, and the wear particles are caught between the wheel and the rail, and it has been experimentally confirmed that an effective adhesion-increasing effect is performed. did.

If the powder generated by the wear of the porous ceramic body is coarse particles, the particles may abrade the wheel tread or rail, so the crystal grain size of the ceramic body may be 0.
．． It is preferable to adjust the particle size of the raw materials used, the firing temperature, etc. so that the particle size is in the range of 1 to 20 μm.

In addition, since the slider 4 of the present invention is composed of a porous ceramic body, its mechanical strength is lower than that of a dense ceramic body, so it is suitable for use in high-speed vehicles. If there is a risk of chipping or cracking, use aluminum,
It is preferable to provide a reinforcing member 7 that is molded or gripped with a suitable metal such as an aluminum alloy.

Hereinafter, a performance test using a slider made of a porous ceramic body containing alumina as a main component, having an average crystal grain size of 3 μm, and an absorption coefficient of 25 will be described.

As the basic configuration of the performance testing machine is shown in Fig. 2, the wheel test piece 2a and the rail test piece R rotate in the direction of the arrow, and the wheel test piece 2a is always screwed onto the virgin surface of the rail test piece R. The wheel test piece 2a is configured to move laterally (moves five circles per 19 rotations of the wheel test piece) in order to roll in a linear manner.

Therefore, the results obtained by this tester substantially correspond to the results obtained in railway vehicles where the contact between the wheels and the rails is temporary.

The test conditions were a contact load of 200 Kf, a rotational speed of both test pieces of 55 rpl, and a slip ratio of 10.4.

The above test results show that the adhesion coefficient is approximately 0.22 when the wheel test piece 2a and the rail test piece R are in a dry state without pressing the slider 4, as shown in FIG. However,
Next, when clear water is sprayed to create a water-lubricated state, the adhesive coefficient is approximately 0.
618, that is, approximately 0.83 when calculated assuming the dry state as 1.
It dropped to .

Next, when the slider 4 is pressed against the tread surface of the wheel test piece 2a under water lubrication at a pressure of IKy/cJ, the adhesion coefficient increases while the wheel test piece 2a rotates 4 to 5 times. 0.
Stable at 33.

This value is approximately 1.5 times higher than that in the dry state, indicating rapid rise characteristics and excellent tack-enhancing effects that cannot be obtained with conventional tack-enhancing sliders.

Incidentally, in the case of a slider made of a conventional A7 alloy casting, when the slider is pressed against a wheel under water lubrication, the adhesive coefficient only increases to the same as in a dry state.

Furthermore, according to the slider of the present invention, after the adhesive coefficient increases, it maintains a constant high adhesive coefficient, indicating that the adhesive increasing effect is more stable than that of the conventional sand scattering method.

As described above, the present invention has a remarkable effect of increasing adhesive force by configuring the adhesion increasing slider with a porous ceramic body, and is effective for high-speed vehicles in place of conventional sand scattering and adhesion increasing sliders. can be applied to

[Brief explanation of drawings]

Fig. 1 is a side view showing an example of a wheel tread sliding device to which the slider of the present invention is applied, Fig. 2 is a perspective view showing the basic configuration of a slider performance tester, and Fig. 3 is a main It is a figure showing the performance test result of the slider of the invention. 2...Wheel, 4...Slider.

Claims (1)

[Claims] 1 Absorption rate 20-3001), crystal grain size 0.1-20μ
A slider for increasing the adhesion of a wheel tread, characterized in that it is made of a porous ceramic body.