JPS582091B2 - Friction shoe device for railway vehicle bogies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention provides an improved friction shoe device for a railroad vehicle bogie.

This friction shoe device has good vertical stability and long friction life.

Railroad vehicle bogies of the type to which this invention relates typically have spaced apart side beams or side frames having openings supporting opposite ends of the bolsters.
A spring-biased friction shoe is provided having a wall that contacts the friction surface of the side frame.

Two friction shoes contact each end of the side frame and the bolster to accommodate the oscillatory motion of the bolster.

There are typically two problems in the design of friction shoes for railroad vehicle bogies.

One of these is to maintain the constancy of the friction shoes to prevent excessive forces from being applied to the bolsters or side frames due to the tilting movement and destroying the friction shoes during the carriage run.

Another problem is to extend the wear life of the friction shoes by uniformly distributing the contact pressure of the friction shoes against the side frame upright surfaces.

An improved friction shoe is disclosed in commonly assigned U.S. Pat. No. 4,109,585, which has a wide wing surface that is sloped relative to the bolster guide surface.

The present invention is a further improvement on this patented invention and provides a friction shoe having an integral sloped surface instead of a wing section.

It is an object of the present invention to provide a friction shoe for a railway vehicle bogie with good vertical stability and long wear life.

In the friction shoe of the present invention, the point of contact between the shoe and the bolster substantially coincides with the center line of the deflection spring, and is also approximately equidistant from the upper and lower edges of the shoe on the side frame upright surface side.

The deflection spring is positioned within the shoe as close to the side frame upright as the required spring radius and wall thickness of the shoe will allow.

In a variant embodiment of the invention, the spring is in contact with an integral lower surface of the wear shoe having an integral sloped surface without wings.

Also, the slope of the shoe or the top radius of the shoe wing can be made smaller than in the prior art.

Furthermore, the length of the vertical surface of the shoe, ie the upright surface of the side frame, can be increased.

The combination of these features provides the friction shoe of the invention with good vertical stability and long wear life.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a side frame 10 having a pair of upright posts 12.
are shown, and these upstanding columns constitute both sides of a bolster opening 14 formed in the side frame.

The bolster 16 is resiliently supported within the bolster opening 14 by a spring 18.

The friction plate 20 may be integrated with the side frame pillar 12,
It may also be appropriately attached to this pillar.

As shown in FIG. 2, pockets 22 are formed in the bolster 16 on both sides of the longitudinal axis 17.

Friction shoes 24 are inserted into these pockets adjacent to each side frame vertical column.

The friction shoe 24 includes a body portion 26 having a friction wall 28 that is connected to the friction surface 30 of the side frame friction plate 20.
comes into frictional contact with.

Friction shoe 24 is biased into frictional contact with friction plate 20 by bias spring 32, which is shown schematically in FIG.

The spring 32 fits into a central spring pocket (not shown) formed in the friction shoe 24 and is also fitted into the bottom wall 3 of the bolster 16.
6 and the upper wall 38 of the friction shoe 24.

The spring 32 presses the sloped wing portion 42 , that is, the upper surface 40 of the wing portion projecting outwardly from both sides of the body portion 26 of the friction shoe 24 , into contact with the guide surface 44 of the bolster 16 .

Of course, FIGS. 1 to 3 show one embodiment of the friction shoe of the present invention, that is, an embodiment of the friction shoe having wing portions.

Another embodiment is shown in FIG. 9, which lacks wings and instead has a sloped surface on the side of the body opposite the upright friction wall.

As shown in FIGS. 4-7, the friction shoe is subject to three types of forces: the deflection spring force S, the bolster tilting force B at the point of contact, and the side frame upright force C.

The vertical column force C is distributed over the entire contact area between the friction shoe surface and the side frame vertical column, but this force is expressed by a single vector that is the resultant of the normal force and the frictional force, and this force is always in the direction of motion. It faces in the opposite direction and has a size proportional to the friction coefficient between the friction shoe and the side frame upright column.

According to the principles of mechanics, the vectors of the above three types of forces must intersect at one point in order for the friction shoe to be balanced as a free object.

In FIG. 4, where lower level bolster movement is shown, and FIG. 5, where upper level bolster movement is shown, the three types of forces intersect at the nominal design contact point CP.

However, when the bolster is tilted relative to the side frame,
As in FIG. 6, where downward tilt bolster movement is shown, and FIG. 7, where upward slope bolster movement is shown, the point of contact is at DC
Move from the design contact point denoted P to the solid line contact point denoted ACP.

For a given angle of inclination of the bolster, the distance traveled by the contact point is proportional to the radius of curvature of the shoe ramp.

In order for the three types of forces acting on the shoe to intersect at a single point, the upright force vector must move upward or downward relative to the shoe surface.

For the friction shoe to be stable, the intersection of the upright force vector and the upright must be within the shoe surface.

If there is no intersection in this range, the shoe will tilt.

In the friction shoe according to the present invention, this contact point is located at a position where the above-mentioned movement is minimized, so even if the bolster is tilted by about 1° from the vertical line, the upright force vector will remain unchanged on the shoe. within the upright plane, and the shoe will not tilt.

An embodiment of a friction shoe having three design limitations of the present invention is shown in FIG. 8, which can avoid uneven wear on the bottom or top of the upright surface of the shoe, which often occurs in prior art friction shoes.

The illustrated friction shoe 24 has a friction wall 28 that contacts a friction surface (not shown) of a side frame.

The centerline of the deflection spring is indicated at 50.

This centerline intersects the sloped surface, ie, the upper wing surface 40, at a point 54, which is also the intersection of the sloped surface 40 and a line 52, which is equidistant from each end of the upright surface.

This intersection is the preferred point of contact between the ramp 40 and the guide surface 44 of the bolster (not shown).

Contact point 54 can be considered a point on the top surface of convex wing 42 having a radius of curvature of approximately 30-40 inches.

The preferred radius of curvature of approximately 76-100 cm is approximately 152 cm (
significantly smaller than conventional friction shoes, which have a radius of curvature of 60 inches).

This radius is 76 cm (30 inches) due to contact stress limits.
It cannot be made much smaller.

The centerline 50 of the deflection spring force should be as close to the friction wall 28 as possible within design limits allowed by a sufficient thickness of the friction wall 28 and a sufficient spring diameter for strength and wear purposes.

With this arrangement, a rotational moment that acts to raise the friction wall 28 from contact with the side frame friction plate 20 (not shown) of the upright column surface, that is, the top or bottom of the friction wall 28 due to the tilting movement of the bolster (not shown), is generated. can be reduced.

In addition, in order to reduce the possibility that either end of the upright column surface 28 will be lifted from contact with the side frame friction plate 20,
The preferred length of the upright surface 28 is the standard 14-15 cm (5.5 cm).
5-6 inches) to 15-16.5 cm (6-6.6 inches).

Another embodiment of a friction shoe having the design limitations of the present invention is shown in FIG.

This type of friction shoe does not have wings, but instead has an integral convex inclined surface 6 that contacts the guide surface of the bolster (not shown).
has 0.

This friction shoe does not have a structure in which a deflection spring is inserted into a cavity, but has an integral lower surface 62, and the force of a deflection spring (not shown) acts on this lower surface from below.

The friction shoe also has an upright surface 64 that contacts the friction surface of the side frame (not shown).

The centerline of the deflection spring force is indicated at 66.

The centerline of the upright column surface 64 is indicated by 68.

These centerlines intersect at a contact point 70 on the convex ramp 60 as shown.

The radius of curvature of the inclined surface 60 is approximately 76-100 cm (30-4
0 inch).

This radius is considerably smaller than the approximately 152 cm (60 inches) of conventional friction shoes.

However, this radius cannot be much smaller than 30 inches due to contact stress limitations.

It is preferred that the centerline 66 of the deflection spring be as close to the upright plane as possible for strength and friction purposes and within design limits for sufficient spring diameter.

Therefore, the rotational moment that acts to raise the upright column surface 64 whose top and bottom parts contact the side frame friction plate (not shown) is reduced.

Also, to reduce the possibility that either end of the upright surface 64 will be lifted out of the contact position, the preferred length of the upright surface 64 ranges from the standard 14-15 cm (5.5-6 inches) to 15-15 cm (5.5-6 inches).
Reduced to 16.5 cm (6-6.5 inches).

Improved friction shoe vertical stability due to the reduced radius of curvature for the shoe ramp is shown in FIGS. 10 and 11.

A prior art large radius friction shoe 81 is shown in FIG.

This design contact point is shown at 80 on the convex ramp.

When the bolster is tilted by an angle θ, the contact point moves to a new contact point 82 as shown.

The large movement of the contact point due to the large radius of curvature of the inclined surface disturbs the balance of the multiple forces acting on the shoe, causing a loss of planar contact along the upright column surface.

For this reason, the upright surface of the friction shoe wears unevenly.

An embodiment of the friction shoe of the present invention is shown in FIG.

The friction shoe 91 has a convex inclined surface with a smaller radius of curvature than the conventional friction shoe shown in FIG.

This design contact point is indicated at 90 on the convex ramp.

When the bolster 94 is tilted by an angle .theta. similar to FIG. 10, the contact point moves to a new contact point 92 as shown.

Due to the small radius of curvature of this inclined surface, the contact point movement described above is smaller than in the case of FIG.

Therefore, the effect on the balance of forces acting on the shoe is much smaller than in conventional shoes, and the possibility of loss of planar contact along the upright surface is reduced.

The chances of uneven wear of the friction shoes are reduced as well.

[Brief explanation of the drawing]

Fig. 1 is a partial side view of a railway vehicle bogie equipped with the device of the present invention; Fig. 2 is a partially enlarged sectional view taken along line 2-2 in Fig. 1; Fig. 3 is a side frame vertical column, friction shoe, and Detailed elevational view of the bolster with parts broken: Figure 4 is a schematic representation of the end of the bolster contacting two friction shoes on a downward leveling movement; Figure 5 is a schematic illustration of the end of the bolster contacting two friction shoes on an upward leveling movement. Figure 6 is a schematic representation of the bolster end in contact with two friction shoes in a downward tilting motion; Figure 7 is a schematic diagram of a bolster end in contact with two friction shoes in an upward tilting motion. Schematic diagram of the end part; FIG. 8 is a detailed side view of one embodiment of the friction shoe of the present invention; FIG. 9 is a side view of another embodiment of the friction shoe of the present invention; FIG. 10 is a detailed side view of an embodiment of the friction shoe of the present invention; A side view of the friction shoe and the bolster shows the amount of movement of the contact point; FIG. 11 is a side view of the friction shoe and the bolster of the present invention, showing the amount of movement of the contact point. 10... Side frame, 12... Pillar, 14... Opening, 16... Bolster, 18... Spring, 20... ...friction plate,
22...Pocket, 24...Friction shoe, 28...Friction wall (vertical column surface), 32...
... Deflection spring, 36 ... Bolster bottom wall, 38.
... Friction shoe upper wall, 40 ... Inclined blade upper surface, 42 ... Inclined blade section, 44 ... Bolster guide surface.

Claims (1)

[Scope of Claims] 1. A side frame having a plurality of vertical pillars forming an opening, a bolster supported within the opening, a friction surface provided on the vertical pillar, a guide surface device for the bolster, and a side frame having a plurality of vertical pillars forming an opening. A friction shoe device disposed between upright columns and having a vertical wall in contact with the friction surface of the upstanding column, for use in a railway vehicle bogie including: a convex wing of the friction shoe device in contact with the guide surface of the bolster; The wing surface is approximately 76-100 cm (76-100 cm).
30-40 inches), and each wing surface contacts each guide surface at one point of contact, which point is approximately on the centerline of the spring under normal bolster operation and is adjacent to the vertical wall. A friction shoe device for a railway vehicle bogie, characterized in that the shoe device is located approximately on the center line of the vehicle. 2. A side frame having a plurality of vertical columns forming an opening, a bolster supported within the opening, a friction surface provided on the vertical column, a guide surface of the bolster, and a side frame arranged between the bolster and the vertical column, and a friction shoe device having a vertical wall in contact with the friction surface of the upright pillar; a convex inclined surface of the friction shoe device in contact with the guide surface of the bolster; a combination of vertical springs contacting a bottom surface and pressing the sloped surface into contact with the guide surface of the bolster, the sloped surface having a radius of curvature of approximately 70-100 cm (30-40 inches); and the inclined surface contacts each guide surface at one contact point,
A friction shoe device for a railway vehicle bogie, wherein the contact point is located approximately on the center line of the spring and approximately on the center line of the vertical wall in a normal bolster operating state. 3. A friction shoe device for a railway vehicle bogie according to item 1 or 2 above, wherein the vertical wall has a length of 15-16.6 cm (6-6.5 inches). 4. A side frame having a plurality of vertical columns forming an opening, a bolster supported within the opening, a friction surface provided on the vertical column, a guide surface for the bolster, and a side frame arranged between the bolster and the vertical column, and a friction shoe device having a vertical wall in contact with the friction surface of the upright pillar; at least one convex inclined surface of the friction shoe device in contact with the guide surface of the bolster; contacting the friction shoe device;
and a vertical spring that presses the inclined surface of the friction shoe into contact with the bolster guide surface, the inclined surface and the guide surface are in contact at at least one contact point, and the inclined surface is in contact with the bolster guide surface. A friction shoe device for a railway vehicle bogie, wherein the friction shoe vertical wall maintains planar contact with the upright friction surface in an operating state and in a state in which the bolster is tilted by 1° or less from a vertical position.