JP6836984B2 - Tread friction element - Google Patents

Description

The present invention relates to a tread brake shoe that is pressed against the tread surface of a wheel of a railroad vehicle to brake the wheel, and a tread surface polisher that polishes the tread surface to prevent a decrease in the friction coefficient between the rail and the wheel. It relates to a tread friction element that acts on a tread surface friction element and includes a solid lubricant that imparts lubricity to a wheel flange portion.

In a railroad vehicle traveling on a curved road, if the flanges of the wheels are not sufficiently lubricated, the wheels will wear due to contact with the rails, and the dimensions of the flanges will change, hindering safe driving. You may get it. Therefore, a device that imparts lubricity to the flange throat of the wheel has been proposed.

For example, in Patent Document 1, the flange portion of the backing plate of the brake shoe is provided with a friction surface that can be engaged with the flange of the wheel, and the friction surface is provided with a friction material containing a solid low friction coefficient modifier. The brake shoes are disclosed. By applying such a modifier to the wheel flange, it can be transferred to the track surface as a result, reducing wear on the wheels and rails, reducing energy consumption, and lowering the noise level. Furthermore, it is said that the climbing tendency of the rail will be reduced. Such a solid friction modifier is said to consist of molybdenum disulfide, graphite, or a conjugate thereof.

On the other hand, in order to prevent a decrease in the coefficient of friction between the rail and the wheel, a device for imparting lubricity to the flange throat of the wheel is incorporated in the tread abrasive that is intermittently pressed against the tread surface of the wheel to polish the tread surface. The rails are also proposed.

For example, Patent Document 2 discloses a method in which an injection tool for injecting oil is embedded in a grinder, and oil is injected from the injection tool toward a wheel to provide a lubricant. Since it is a liquid lubricant, it is necessary to stabilize the gap of the injector with respect to the wheel, so the retracting position of the abrasive is regulated.

Further, Patent Document 3 discloses an integrated tread friction element in which a solid lubricant is adhered to a side surface of a tread surface friction element that acts on a tread surface such as a tread surface polisher or a tread surface brake shoe (brake shoe), and in particular, friction. Disclosed is an integrated tread friction element in which an adhesive layer that provides a heat insulating function is interposed between the element and the solid lubricant. The friction element is pressed against the tread surface of the wheel to generate frictional heat, and the back metal fixing the friction element is also heated. Here, the solid lubricant is not in contact with the back metal, and is further insulated by the adhesive layer between the solid lubricant and the friction element. Therefore, the solid lubricant is not heated, and for example, a resin-based lubricant made of resin or the like can be used.

Japanese Unexamined Patent Publication No. 2001-18977 Japanese Unexamined Patent Publication No. 2013-75666 JP-A-2009-96280

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 is relatively bonded by interposing an adhesive layer that provides 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 body are significantly different, and abnormal wear is observed on the tread portion of the wheel corresponding to the adhesive layer portion.

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

The tread friction element according to the present invention is a tread friction element that is pressed against the tread surface of a wheel of a railroad vehicle and acts on the tread surface, and has a friction element main body portion whose back surface is attached to a back plate portion connected to a drive mechanism. In an integrated tread friction element that combines a solid lubricant portion that protrudes to the side portion of the friction element main body portion and imparts lubricity to the wheel flange portion, the boundary between the friction element main body portion and the solid lubricant portion. It is characterized in that the layer is given a compositional inclination in the thickness direction.

According to such an invention, it is possible to impart lubricity to a wheel flange portion while maintaining a good tread surface, and to incline the composition of the boundary layer between the friction element main portion and the solid lubricant portion, thereby thermally and mechanically. The resistance can be increased to prevent the solid lubricant from falling off.

In the above invention, the pressing surface against the tread may be a smooth surface having no step from the friction element main body to the boundary layer. According to such an invention, abnormal wear of the tread surface can be satisfactorily 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 such an invention, the entire back surface of the boundary layer having an inclined composition can be supported by a back plate, and the shearing force on the boundary layer can be reduced.

In the above-described invention, the solid lubricant portion and the friction element main body portion may be characterized in that a part thereof contains a thermosetting resin. Further, the thermosetting resin may be characterized in that it penetrates into the friction element main body made of a porous material to provide the boundary layer. Further, the thermosetting resin may be characterized by containing a phenol resin. According to such an invention, a boundary layer having a sloped composition can be easily obtained.

In the above invention, the solid lubricant portion may contain molybdenum disulfide and graphite, or a mixture thereof. According to such an invention, a boundary layer having a sloped composition can be easily obtained.

It is a side view of the tread friction element and a wheel according to the Example of this invention. It is a perspective view of the tread friction element according to the Example of this invention. It is a front sectional view of a tread friction element and a wheel according to an Example of this 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 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 a wheel 1 of a railway vehicle and a position separated from the tread surface 2. That is, the tread friction element 10 can act on the tread 2 by being pressed against the tread 2 by the drive mechanism 9 to polish the tread 2 or brake the wheel 1 via the tread 2. That is, the tread friction element 10 is a tread abrasive or a tread brake shoe that acts on the pressed tread surface 2. The tread friction element 10 is used when the wheel 1 needs to be braked or when the tread surface 2 needs to be polished while the vehicle is running. Since it is used while the vehicle is running, the tread friction element 10 is arranged within a range that does not come into contact with the rail 4 due to the convenience of the installation position of the drive mechanism 9. That is, the tread friction element 10 may be arranged above the wheel 1 as shown in the figure, and may also be arranged 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 (gauge side) of the tread surface 2 of the wheel 1, and the flange 3 is located inside the tread surface friction element 10 when the tread surface friction element 10 comes into contact with the tread surface 2.

As shown in FIG. 2, the tread friction element 10 is provided on a back plate 11 connected to a drive mechanism 9, a friction element body 12 whose back surface is supported by the back plate 11, and a side portion of the friction element body 12. It includes a solid lubricant portion 13 that protrudes and the back plate 11 is not arranged on the back surface side.

The friction element main body portion 12 and the solid lubricant portion 13 are combined and integrated via a 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 tilting the composition, and is a part of the friction element main body portion 12 and also a part of the solid lubricant portion 13. The friction element main body portion 12 and the solid lubricant portion 13 have a curved surface in which the shape of the contact surface 15 that abuts on the tread surface 2 matches the shape of the tread surface 2. On the other hand, the surface of the friction element main body 12 on the back plate 11 side is made substantially flat according to the shape of the back plate 11. The back plate 11 is provided with a connection fitting 11a used for connecting to the drive mechanism 9 on the back surface.

Further, the boundary layer 14 is located below the back plate 11 so that the entire back surface thereof is supported by the back plate 11. As a result, the boundary layer 14 is supported by the back plate 11 so as not to generate a shearing force in the direction along the main surface thereof. Further, the contact surface 15 pressed against the tread 2 is a smooth surface having no step from the friction element main body 12 toward the boundary layer 14, so as to prevent abnormal wear of the tread 2. ..

The friction element main body portion 12 contains a solid lubricant forming the solid lubricant portion 13 as a part thereof, so that the boundary layer 14 having a sloped composition can be easily obtained. Therefore, when the thermosetting resin is used as a solid lubricant, a porous material having voids to be impregnated before the thermosetting resin is cured can be used. Even if it is not a porous material, it may be any material as long as it can obtain the boundary layer 14 whose composition is inclined together with the thermosetting resin of the solid lubricant portion 13. When a material that does not melt even at a higher temperature is used 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 whose composition is inclined by molding such as firing and sintering. It can be a friction element obtained from a resin molded product, a sintered alloy, or the like. That is, the boundary layer 14 between the friction element main body portion 12 and the solid lubricant portion 13 is given a composition inclination in the thickness direction thereof.

As described above, the solid lubricant portion 13 is mixed with a thermosetting resin that can be impregnated and cured when the friction element main body 12 is made of a porous material, or a raw material powder of the friction main body 12. It consists of a material that can be molded into a friction element above. For example, thermosetting resins such as phenol resin, molybdenum disulfide, graphite, and mixtures thereof can be used. When a thermosetting resin is used, the composition of the boundary layer 14 can be easily inclined. 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 mixing ratio of the friction element with the raw material powder, and the composition gradient can be easily obtained. Be done.

As shown in FIG. 3, the tread friction element 10 inclines the contact surface 15 along the inclination of the tread surface 2 in the 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 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 the friction between the rail 4 and the wheel 1. The tread surface 2 can be polished so as 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. Further, the solid lubricant portion 13 can absorb the difference in thermal expansion from the friction element main body portion 12 by the boundary layer 14 having a composition gradient when the temperature rises, and can enhance the thermal resistance. Further, the shearing force in the direction along the main surface of the boundary layer 14 can also be dispersed by the composition inclination in the thickness direction of the boundary layer 14, and the mechanical resistance can be enhanced. As a result, the solid lubricant portion 13 is prevented from falling off.

Although the typical examples according to the present invention and the modified examples accompanying the present invention have been described above, the present invention is not necessarily limited to these, and can be appropriately modified by those skilled in the art. That is, a person skilled in the art will be able to find various alternative examples and modifications without departing from the attached claims.

10 Tread friction element 11 Back plate 12 Friction body part 13 Solid lubricant part 14 Boundary layer

Claims (7)

A tread friction element that is pressed against the tread of a railroad vehicle wheel and acts on the tread.
The friction element body with the back attached to the back plate connected to the drive mechanism,
The side portion is arranged on the side portion of the friction element main body portion, is outside the back plate portion, and is pressed against the tread surface of the friction element main body portion and is pressed against the throat of the flange of the wheel. In an integrated tread friction element that combines a solid lubricant part that gives lubricity to the flange part,
The friction material / lubricating material composition inclination is given in the thickness direction to the boundary layer at the boundary between the friction element main body and the solid lubricant parts, which are integrated with each other. Tread friction element characterized by. The tread 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 portion toward the boundary layer. The tread friction element according to claim 1 or 2, wherein the boundary layer is located below the back plate portion. The tread friction element according to any one of claims 1 to 3, wherein the solid lubricant portion and the friction element main body portion contain a thermosetting resin as a part thereof. The tread friction element according to claim 4, wherein the thermosetting resin penetrates into the friction element main body made of a porous material to provide the boundary layer. The tread friction element according to claim 4 or 5, wherein the thermosetting resin contains a phenol resin. The tread friction element according to any one of claims 1 to 3, wherein the solid lubricant portion contains molybdenum disulfide and graphite, or a mixture thereof.

Images