JPH03204302A - Independent wheel of rolling stock - Google Patents

Abstract

PURPOSE:To increase gravitational restoring force, and to prevent weaving creak, and wear of rails, when the wheels move right and left from the neutral position to the rails more than a prescribed value, by forming the tread surface in such a way that the difference between the angles made by the tangential lines at the points where the respective right and left wheel tread surfaces are in contact with the top surfaces of the rail heads and by the horizontal surface becomes greater than a prescribed value. CONSTITUTION:The tread surface is formed in such a way that the difference between the angles alphaR, alphaL formed by the tangential lines at the contact points AR, AL for determining the right and left directional component forces QR, QL of the normal forces NR, NL and by the horizontal surface becomes more than 0.1 rad, when right and left wheels 2, 3 move right and left more than 2 mm, while the respective wheels 2, 3 are in contact with the head surfaces 4 of rails 1 at contact points AR, AL.Thereby the gravitational restoring force Y to be obtained by the difference QR-QL between the right and left component forces QR, QL can be increased. By this constitution, weaving, wear of rails, and creak at the passage of a curve can be prevented, and also weight can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention enables prevention of snaking motion of railway vehicles when running at high speeds, prevention of squeaks when passing through curves, prevention of wear and tear on wheels and rails, and weight reduction. That is.

[Conventional technology]

Railway wheels have conventionally used an integrated east wheel in which the left and right wheels are connected by an axle. The tread of this wheel is shaped so that the wheel diameter increases toward the inner flange, and as a result, when passing through a curve, the wheel flange approaches the outer rail, increasing the wheel diameter, and vice versa. Since the wheel flange portion is separated from the inner rail, the wheel diameter becomes smaller, and the vehicle is steered along the curve due to the difference in diameter between the left and right wheels.

However, in this structure, although a restoring force is always exerted so that the wheels run evenly with respect to the rail, snaking behavior, which is an unstable divergent vibration phenomenon, is likely to occur during high-speed running.

When developing high-speed bogies, it has been difficult to ensure both stability in meandering behavior and good curve passing performance, as well as to promote weight reduction. The requirements for a vehicle in terms of meandering stability and curve passing performance are completely opposite, as shown in Table 1r. In the past, a compromise has been made in each specification depending on whether the bogies being designed emphasize one performance or the other, and it is difficult to say that they are proactively achieving both performances.

[Problems that Jiku tries to solve]

In the above-mentioned conventional high-speed bogies, it is difficult to maintain stability in meandering behavior, ensure good curve passage performance, and promote weight reduction. Furthermore, in the case of integrated wheels, a slight slip occurs between the wheel tread and the top surface of the rail due to the difference in diameter of the wheels during running. This accelerates the wear of the wheels and rails, causing squeaks especially when slippage is significant on curved sections.

Independent wheels exist to solve these problems. In this structure, the left and right wheels are not connected by an axle, and each can rotate independently. As a result, there is no meandering motion, and minute slips between the wheels and the rails are greatly reduced, which is effective in preventing wear. Furthermore, since the wheelbase can be shortened, it is also effective in reducing weight. However, since this wheel does not have the restoring force that an integrated wheel has due to the difference in diameter between the left and right wheels, it has the disadvantage that the wheel runs biased toward one of the rails, and has traditionally been considered a practical middle-neck.

[Means to solve the problem]

The present invention has been made to solve the above-mentioned drawbacks, and by creating a tread shape in which the difference in contact angle between the left and right independent wheel treads is as large as possible at the portion where they contact the top surface of the rail, The difference between the restoring forces of the left and right wheels due to gravity is increased to move the flange on the biased side away from the rail, thereby preventing bias toward one of the rails during driving.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 4.

As shown in FIG. Right wheel 2, left wheel 3 on top
Consider a situation in which the wheel is rolling. These wheels are independent wheels that can independently rotate in the direction of travel, but move as a unit when moving in the left-right direction or rotating around a vertical axis. Figure 1 shows a state in which these wheels are oriented to the right with respect to the rail. Each wheel is in contact with the rail top surface 4 at points AR and AL, respectively. The horizontal component forces QR and QL of the normal forces NR and NL at these contact points are given by QR=NRαRPOαRQL=NLαLphantomPOαL. Here, αR5αL is the contact angle that is the angle between the tangent at the contact point and the horizontal plane, and PO is the average load in the vertical direction applied to the wheel.

In the end, the restoring force Y in the left and right direction acting on the pair of left and right wheel axles is given by Y=QR-QL=PO(αR-αL). This Y is called the gravitational restoring force. In order to increase the gravitational restoring force, the shape of the wheel tread 5 may be determined so that αR−αL becomes larger according to the above equation.

An example of a wheel tread shape designed based on this idea is the independent wheel tread shape shown in FIG. Third
The figure shows the so-called basic tread shape commonly used on conventional lines.

As shown in FIG. 4, while the contact angle difference between the left and right wheels is almost 0 with the conventional basic tread shape, a value of 0.1 rad or more can be obtained with the independent wheel tread shape.

The surface shape is a tread shape that emphasizes curve passing performance, and is designed to increase the difference in radius between the left and right wheels. The concept is fundamentally different from the present tread shape, which is designed to increase the contact angle difference between the left and right wheels.

〔Effect of the invention〕

This makes it possible to develop a vehicle that has both meandering stability and good curve passing performance, which have been considered difficult to achieve in railway vehicles. As a result, it is possible to prevent snaking when driving at high speeds, prevent squeaks when passing through curves, and prevent wear and tear on wheels and rails.

Furthermore, since no meandering motion occurs, the wheelbase distance, which is the longitudinal distance between the front and rear axles of the truck, can be shortened, and the weight of the truck can be reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an explanatory diagram of the gravitational restoring force generated from the contact angle difference between the left and right wheels. FIG. 2 shows an embodiment of the independent wheel tread according to the present invention. Figure 3 shows the basic tread shape currently widely used in conventional line vehicles. Fourth
The figure shows a comparison of the contact angle surface shapes of the left and right wheels. Table 1 Conflict between snaking stability and curve passing performance 1 ・ 2 ・ 3 ・ 4 ・ 5 ・ AR. N.R. Q.R. PR. O αR1 ΦRail, right wheel, left wheel, rail top surface, wheel tread AL...Contact point N1 between the rail top surface and wheel tread...Normal force at the contact point QL...Left-right direction component of normal force Force PL...Vertical component of normal force...Average vertical load applied to the wheel

Claims (1)

[Claims] For independent wheels that have a structure in which the left and right wheels rotate independently, when the wheels move 2 mm or more in the left-right direction from the neutral position with respect to the rail in the section where the vehicle is used,
An independent wheel for a railway vehicle, characterized in that the tread shape has a contact angle difference of 0.1 rad or more between the tangent of the part where the left and right wheel treads contact the top surface of the rail and the horizontal plane, thereby increasing the restoring force due to gravity. .