JP2019082230A - Tread friction piece - Google Patents

Abstract

To provide a tread friction piece which gives a solid lubricant for giving lubricity to a flange portion of a wheel while maintaining a good tread.SOLUTION: A tread friction piece pressed against a tread of a wheel of a railway vehicle to be acted on the tread is provided. In an integrated type tread friction piece made by assembling a friction piece body portion that is attached to a back plate portion connecting to a drive mechanism on a back surface, and a solid lubricant portion that protrudes to a side part of the friction piece body portion and gives lubricity to the flange portion of the wheel, composition inclination in a thickness direction thereof is given to a boundary layer of the friction piece body portion and the solid lubricant portion.SELECTED DRAWING: Figure 2

Description

  The present invention is a tread surface controlling element which is pressed against a tread surface of a wheel of a railway vehicle to brake the wheel, and a tread surface such as a tread surface polishing element for polishing the tread surface to prevent a decrease in the friction coefficient between the rail and the wheel. In particular, the present invention relates to a tread friction element including a solid lubricant which imparts lubricity to a flange portion of a wheel.

  In a railway vehicle traveling on a curved road, if the flanges of the wheels are not sufficiently lubricated, the contact with the rails causes wear of the wheels, and the dimensions of the flanges change, which hinders safe traveling. I also get it. Therefore, a device has been proposed which imparts lubricity particularly to the flange throat of the wheel.

  For example, in Patent Document 1, the flange portion of the backing plate of the brake shoe is provided with a friction surface engageable with the wheel flange, and the friction surface is provided with a friction material containing a solid low friction coefficient modifier. Disclosed a brake shoe. By applying such a modifier to the wheel flange, it can consequently be transferred to the track surface, reducing wear on the wheels and rails, reducing energy consumption and reducing noise levels. In addition, it is said that it will reduce the climb tendency of the rail. Such a solid friction modifier is made of molybdenum disulfide, graphite or a combination thereof.

  On the other hand, in order to prevent a decrease in the coefficient of friction between the rail and the wheel, a device is provided which imparts lubricity to the flange throat of the wheel with respect to a tread surface polishing pad which is intermittently pressed against the tread of the wheel to polish the tread. Some are also proposed.

  For example, Patent Document 2 discloses a method in which an injection tool for injecting oil is embedded in a polishing pad, and oil is injected from the injection tool toward the wheel to apply a lubricant. In addition, since it is a liquid lubricant, it is necessary to stabilize the gap with respect to the wheel of the injection tool, so that the retreat position of the abrasive is restricted.

  Furthermore, Patent Document 3 discloses an integrated tread friction element in which a solid lubricant is adhered to the side surface of a tread surface friction element acting on a tread surface such as a tread surface grinding element or a tread surface brake shoe (brake shoe). Disclosed is an integrated tread friction element in which an adhesive layer for providing a heat insulating function is interposed between a child and a solid lubricant. The friction element is pressed against the tread of the wheel to generate frictional heat, and also heats the back metal fixing the friction element. Here, the solid lubricant is not in contact with the back metal, and furthermore, the adhesive layer between the solid lubricant and the friction element is also thermally insulated. Therefore, the solid lubricant is not heated, and it is possible to use, for example, a resin-based lubricant made of a resin or the like.

JP, 2001-18797, A JP, 2013-75666, A JP, 2009-96280, A

  As described above, in the integrated tread friction element in which the solid lubricant is adhered to the side surface of the friction element, the solid lubricant can be relatively separated by interposing an adhesive layer providing a heat insulating function between the friction element and the solid lubricant. It becomes possible to use a resin-based lubricant having a low melting point. On the other hand, it was found that the hardness of such a resin-based lubricant and the friction element main body were significantly different, and abnormal wear was observed on the tread surface portion of the wheel corresponding to the adhesive layer portion.

  The present invention has been made in view of the above situation, and an object thereof is to provide a tread surface friction element provided with a solid lubricant which imparts lubricity to a wheel flange while maintaining a good tread surface. It is in.

  The tread friction element according to the present invention is a tread friction element pressed against and acting on a tread surface of a wheel of a railway vehicle, wherein the friction element body has a back plate attached to a back plate portion connected to a drive mechanism. An integral type tread surface friction element combined with a solid lubricant portion projecting on a side portion of the friction element main body and imparting lubricity to a flange portion of the wheel; a boundary of the friction element main portion and the solid lubricant portion It is characterized in that the layer is given a compositional gradient in its thickness direction.

  According to this invention, it is possible to impart lubricity to the flange portion of the wheel while maintaining a good tread surface, and thermally and mechanically by making the boundary layers of the friction element main body portion and the solid lubricant portion inclined. The resistance can be enhanced to prevent the solid lubricant portion from falling off.

  In the invention described above, the pressing surface against the tread surface may be a smooth surface having no step from the friction element main body toward the boundary layer. According to this invention, abnormal wear of the tread surface can be well prevented, and a good tread surface can be maintained.

  In the above invention, the boundary layer may be located below the back plate portion. According to this invention, the entire back surface of the compositionally inclined boundary layer can be supported by the back plate, and the shear force on the boundary layer can be reduced.

  In the above-described invention, the solid lubricant portion and the friction element main body may partially include a thermosetting resin. The thermosetting resin may be introduced into the friction element main body made of a porous material to provide the boundary layer. Further, the thermosetting resin may be characterized by including a phenol resin. According to this invention, it is possible to easily obtain a compositionally graded boundary layer.

  In the above invention, the solid lubricant portion may be characterized by containing molybdenum disulfide and graphite, or a mixture thereof. According to this invention, it is possible to easily obtain a compositionally graded boundary layer.

FIG. 2 is a side view of a tread friction element and a wheel according to an embodiment of the present invention. 1 is a perspective view of a tread friction element according to an embodiment of the present invention. FIG. 5 is a front sectional view of a tread friction element and a wheel according to an embodiment of the present invention.

  The tread friction element according to the present invention will be described in detail with reference to FIGS. 1 to 3.

  As shown in FIG. 1, the tread surface friction element 10 is supported by a drive mechanism 9 so as to be movable between a position in contact with the tread surface 2 of the wheel 1 of the railway vehicle and a separated position. That is, the tread surface friction element 10 can be applied to the tread surface 2 by pressing the tread surface 2 by the drive mechanism 9 and grinding the tread surface 2 or braking the wheel 1 via the tread surface 2. That is, the tread friction element 10 is, for example, a tread sand or a tread surface controller that acts on the tread 2 pressed. The tread 10 is used when it is necessary to brake the wheel 1 or when it is necessary to polish the tread 2 while the vehicle is traveling. Since the tread surface friction element 10 is used while the vehicle is traveling, the tread surface friction element 10 is disposed depending on the installation position of the drive mechanism 9 and the like in a range not contacting the rail 4. That is, in addition to being disposed above the wheel 1 as shown in the figure, the tread surface friction element 10 can also be disposed in front of or behind the wheel 1 with respect to the traveling direction of the vehicle. A flange 3 is provided on the inside (track side) of the tread 2 of the wheel 1, and the flange 3 is located inside the tread friction element 10 when the tread friction element 10 abuts on the tread 2.

  As shown in FIG. 2, the tread surface friction element 10 is provided on the back plate 11 connected to the drive mechanism 9, the friction element main body 12 supported on the back surface by the back plate 11, and the side portions of the friction element main body 12. And a solid lubricant portion 13 which does not have the back plate 11 disposed on the back side.

  The friction element main body 12 and the solid lubricant portion 13 are combined and integrated through the boundary layer 14 in which the ratio of the composition components is inclined to each other. That is, the boundary layer 14 has a width W for compositional inclination, and is a part of the friction element main body 12 and a part of the solid lubricant part 13. The friction element main body 12 and the solid lubricant portion 13 have a curved surface in which the shape of the contact surface 15 in contact with the tread 2 matches the shape of the tread 2. On the other hand, the surface on the back plate 11 side of the friction element main body 12 is substantially flat according to the shape of the back plate 11. The back plate 11 is provided with a connection fitting 11 a used for connection to the drive mechanism 9 on the back surface.

  Also, the boundary layer 14 is located below the back plate 11 so that the entire back surface is supported by the back plate 11. By this, the boundary layer 14 is supported by the back plate 11 so as not to generate a shear force in the direction along its main surface. Furthermore, the contact surface 15 pressed against the tread 2 is a smooth surface having no step from the friction element body 12 toward the boundary layer 14, and abnormal wear of the tread 2 is prevented. .

  The friction element main body 12 includes the solid lubricant which forms the solid lubricant portion 13 in a part thereof, and the boundary layer 14 whose composition is inclined can be easily obtained. Therefore, when using a thermosetting resin as a solid lubricant, it is possible to use a porous material having voids to be impregnated before curing the thermosetting resin. Even if it is not a porous material, it may be any material that can obtain the boundary layer 14 whose composition is inclined with the thermosetting resin of the solid lubricant portion 13. Also, when using a material that does not melt even at higher temperatures as a solid lubricant, it is molded from a raw material powder that can be mixed with these materials before molding to obtain a boundary layer with an inclined composition by forming processing such as firing and sintering. It can be used as a friction element obtained by a resin molded body, a sintered alloy or the like. That is, the boundary layer 14 between the friction element body 12 and the solid lubricant portion 13 is given a compositional inclination in the thickness direction.

  As described above, the solid lubricant portion 13 is mixed with a thermosetting resin that can be impregnated and hardened when the friction element main portion 12 is made a porous material, and a raw material powder of the friction element main portion 12 It consists of a material that can be shaped into a friction element above. For example, thermosetting resin such as phenol resin, molybdenum disulfide, graphite, and a mixture thereof can be used. When a thermosetting resin is used, the boundary layer 14 can be easily compositionally graded. On the other hand, when a material having a relatively high melting temperature such as molybdenum disulfide is used, the boundary layer 14 can be formed by changing the compounding ratio of the friction material to the raw material powder, and the composition gradient can be easily obtained. Be

  As shown in FIG. 3, the tread surface friction element 10 inclines the contact surface 15 along the inclination of the tread surface 2 in a cross section including the axle of the wheel 1. Further, the solid lubricant portion 13 can be pressed against the throat of the flange 3. As a result, the tread surface friction element 10 can maintain good braking of the wheel 1 while providing lubricity to the flange portion including the throat of the flange 3 or friction between the rail 4 and the wheel 1 The tread 2 can be polished to prevent a decrease in the coefficient. That is, a good tread 2 can be maintained.

  At this time, the solid lubricant portion 13 is not connected to the back plate 11, and the temperature rise is suppressed. Furthermore, when the temperature rises, the solid lubricant portion 13 can absorb the difference in thermal expansion with the friction element main portion 12 with the composition-graded boundary layer 14 and can enhance the thermal resistance. In addition, the shear force in the direction along the main surface of the boundary layer 14 can also be dispersed by the compositional gradient in the thickness direction of the boundary layer 14 to improve mechanical resistance. By these, the solid lubricant portion 13 is prevented from falling off.

  As mentioned above, although the typical example by the present invention and the modification accompanying it were described, the present invention is not necessarily limited to this, and can be suitably changed by those skilled in the art. That is, one of ordinary skill in the art would be able to find various alternative embodiments and modifications without departing from the scope of the appended claims.

DESCRIPTION OF SYMBOLS 10 tread surface friction element 11 back plate 12 friction element main-body part 13 solid lubricant part 14 boundary layer

Claims (7)

A tread friction element which is pressed against a tread of a wheel of a railway vehicle and acts on the tread,
A friction element main body attached to the back surface to a back plate connected to the drive mechanism;
In an integrated tread surface friction element combining a solid lubricant portion disposed on a side portion of the friction element main body and providing lubricity to a flange portion of the wheel,
A tread surface friction element characterized in that composition gradients in the thickness direction are given to a boundary layer of the friction element main body portion and the solid lubricant portion.   The tread surface friction element according to claim 1, wherein the pressing surface against the tread surface is a smooth surface having no step from the friction element main body toward the boundary layer.   The tread surface friction element according to claim 1, wherein the boundary layer is at a lower portion of the back plate portion.   The tread surface friction element according to any one of claims 1 to 3, wherein the solid lubricant portion and the friction element main portion partially contain a thermosetting resin.   The tread surface friction element according to claim 4, wherein the thermosetting resin intrudes into the friction element main body made of a porous material to provide the boundary layer.   The tread of claim 4 or 5, wherein the thermosetting resin comprises a phenol resin. The tread friction element according to any one of claims 1 to 3, wherein the solid lubricant portion includes molybdenum disulfide and graphite, or a mixture thereof.

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