JP4553182B2 - Lubricant composition - Google Patents

Description

  The present invention relates to a lubricant composition for reducing wear and suppressing slippage.

  Since railcars travel with a lateral pressure according to the curve passing performance when passing through a sharp curve, wear occurs on the rail side surface on the outer track side of the curve and the flange portion of the wheel that contacts this rail side surface. To do. Further, this lateral pressure causes squealing (frictional noise) of the inner and outer tracks of the curve and also causes wavy wear generated on the tread of the rail on the inner track side. In order to reduce such excessive lateral pressure and wear, a friction modifier or lubricating oil that reduces the adhesion between the wheel and the rail is applied to the rail top surface or the tread surface of the wheel. It is applied to the boundary between the top surface of the rail on the outer rail side and the side surface of the head, or the boundary between the wheel flange and the tread surface.

  For example, a conventional friction modifier injection device (Prior Art 1) has a tank that contains a VHPF friction modifier with a large friction coefficient and a HPF friction modifier with a small friction coefficient, and a travel point detection that detects the travel point of the vehicle. The injection position storage means for storing the injection position of the VHPF friction modifier and the HPF friction modifier, the traveling position detected by the traveling point detection means and the injection position stored by the injection position storage means And an injection control means for instructing to inject either the VHPF friction modifier or the HPF friction modifier from the tank based on the determination result of the injection determination means (for example, patent document) 1). In such a conventional friction modifier injection device, the VHPF friction modifier is selected in the station front section or steep section where the friction coefficient needs to be increased, and HPF friction adjustment is performed in the curve section where the friction coefficient needs to be reduced. These friction modifiers are sprayed on the rail top surface by selecting the agent.

  A conventional in-vehicle oiling device (prior art 2) includes an angular velocity sensor that detects an angular velocity of a vehicle, an electromagnetic pump that injects lubricating oil, and a control unit that operates an electromagnetic pump based on the angular velocity detected by the angular velocity sensor. (For example, refer to Patent Document 2). In such a conventional in-vehicle oiling device, the bending direction of the curved road is determined based on the angular velocity detected by the angular velocity sensor, and the electromagnetic pump is operated faster as the angular velocity is larger, Lubricating oil is injected at the boundary between the top surface of the rail and the side surface of the head or the boundary between the flange of the wheel and the tread surface.

  A conventional automatic rail oiling device (prior art 3) includes a train detection unit that detects passage of a train, a compressed air supply unit that supplies compressed air into the oil tank, and a nozzle that injects oil from the oil tank. And a control unit that supplies compressed air to the compression supply unit based on a train detection signal output by the train detection unit (see, for example, Patent Document 3). In such a conventional automatic rail oiling device, when the passage of a train is detected, compressed air is supplied, and oil is injected from the nozzle onto the side surface of the rail head that comes into contact with the flange portion of the wheel.

Japanese Patent Laid-Open No. 2001-151110

JP 11-173495 A

JP 2002-37068 A

  In the prior art 1, it is necessary to detect the travel point of the vehicle, determine the injection position of the friction modifier, and select one of two types of friction modifiers having different friction coefficients, which complicates the apparatus. There was a problem that the cost of the friction modifier was high. Further, in the prior arts 2 and 3, when the lubricating oil or the like sprayed between the rail head side surface and the wheel flange surface adheres to the rail top surface or the wheel tread surface, the wheel moves on the rail during power running (drive). There is a possibility that the wheel slips on the rail, or the wheel slides on the rail during braking. As a result, there is a problem in that extraordinary maintenance is increased due to the occurrence of excessive friction on the rails due to idling or the occurrence of flats in which the treads of the wheels are locally irregular due to sliding. In addition, there is a problem that the train is delayed when the stop station is overrun by sliding.

  An object of the present invention is to provide a lubricant composition capable of reducing wear between a contact surface and a contacted surface and suppressing slippage between them.

The present invention solves the above-mentioned problems by the solving means described below.
In addition, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this embodiment.
According to the first aspect of the present invention, when the railway vehicle passes a sharp curve, wear between the flange surface (2b) of the wheel (2) of the railway vehicle and the inner top surface (1b) of the rail (1) is reduced. It is a lubricant composition that reduces and suppresses the slip between them, and the traction coefficient increases with an increase in the slip ratio in a slip region in which a macroscopic slip to slip or slip occurs due to acceleration or deceleration of the railway vehicle. It exhibits traction characteristics and includes a naphthenic compound and a modified silicone oil, the naphthenic compound is naphthenic acid, the modified silicone oil is an alkyl-modified silicone oil , and the blending ratio of the alkyl- modified silicone oil is 1 It is a lubricant composition characterized by being -30 mass%.

  According to this invention, it is possible to reduce wear between the contact surface and the contacted surface and to suppress slippage between them.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view showing a state of a railway member in which a lubricant composition according to an embodiment of the present invention is used. FIG. 2 is an enlarged front view showing a portion II in FIG. FIG. 3 is a side view seen from the III direction of FIG.
The rail 1 is a rail member that guides the wheel 2 and includes a top surface (head upper surface) 1a that supports the wheel 2 and an inner head surface (inner head side surface) 1b that is continuous with the head surface 1a. ing. The wheel 2 is a railway member that is in rotational contact with the rail 1, and includes a tread surface 2 a that contacts the top surface 1 a of the rail 1 and receives frictional resistance, and a rail 1 on the outer gauge side when the railway vehicle passes a sharp curve. And a flange surface 2b that is in contact with the inner parietal surface 1b and receives frictional resistance. As shown in FIGS. 1 and 2, a lateral pressure Q acts on the inner top surface 1b and the flange surface 2b when the railway vehicle passes a sharp curve in the direction of the arrow. As a result, the medial parietal surface 1b and the flange surface 2b become a place where the wear is intense because of the violently high surface pressure causing sliding contact, and when such wear progresses, the shape of the parietal surface 1a and the tread surface 2a changes and safety is increased. In addition, the riding comfort decreases and the maintenance cost increases.

FIG. 4 is a diagram showing ideal traction characteristics.
The traction characteristics shown in Fig. 4 are curves representing the relationship between the traction coefficient t and the slip ratio (Reference: Takumi Ban, et al., Evaluation of Adhesive Properties of Wheel / Rail Lubricants, Railway Research Institute Report, December 2001, Page 17 To page 20), the vertical axis represents the traction coefficient t, and the horizontal axis represents the slip ratio. Here, the traction coefficient t is the tangential force (tangential force P shown in FIG. 3) acting on the rail 1 acting on the rail 1 from the wheel 2 to the rail 1 (normal force W shown in FIG. 3). ) (The tangential force coefficient), which represents the magnitude of transmission of the braking force and the driving force, and the coefficient when the tangential force is the maximum value is called the adhesion coefficient. The slip ratio is the absolute value of the difference (U ₁ −U ₂ ) between the two rotating bodies when the rotating body having the circumferential speed U _{1 and} the rotating body having the circumferential speed U ₂ are in rotational contact. one of the circumferential velocity U _1, the value obtained by dividing the U ₂ of the rotating body, or the absolute value of the two peripheral speeds of the difference in rotational member two peripheral speed of the average value of the rotating body (U ₁ + U _2/2 ) Divided by.

  Curve I shown in FIG. 4 is a traction characteristic when a normal lubricating oil is used. In the curve I, the traction coefficient t becomes small when passing through the sharp curve, and the lateral pressure Q generated between the rail 1 and the wheel 2 shown in FIG. 1 can be suppressed. However, when the vehicle accelerates or decelerates and the slip rate increases, the traction coefficient t further decreases, causing idling and sliding. Curve II is an ideal traction characteristic. In the range of the slip rate that occurs when passing through a sharp curve, the traction coefficient t becomes small, suppresses the occurrence of lateral pressure Q, and macroscopic slip that leads to idling or sliding due to acceleration or deceleration of the vehicle. When this occurs, the traction coefficient t is instantaneously shifted. For this reason, it is desirable to use a lubricant composition exhibiting such traction characteristics.

  As such a lubricant composition, one containing a naphthenic compound and silicone oil is preferable. As such a naphthenic compound, for example, naphthenic acid is preferable, and as the silicone oil, for example, modified silicone oil is preferable. The blending ratio of the silicone oil is preferably 1 to 30 mass% because the effect is lost when the blending ratio is too low and the mixing with the naphthenic compound becomes insufficient when the blending ratio is too high. The lubricant composition preferably contains a synthetic traction oil and a solid lubricant. For example, molybdenum disulfide is preferable as the solid lubricant. The blending ratio of molybdenum disulfide is preferably 0.1 to 10.0 mass% because if the blending ratio is too low, the effect is lost, and if the blending ratio is too high, nozzles and piping may be clogged at the time of ejection. The lubricant composition is supplied to the inner top surface 1b or the flange surface 2b by, for example, an oil application device having an injection nozzle installed on the ground side, or a coating composition having an application roller installed on the upper side of the vehicle and in rotational contact with the wheels. It is applied to the inner top surface 1b or the flange surface 2b by an oil device.

The lubricant composition according to the embodiment of the present invention has the following effects.
(1) In this embodiment, the lubricant composition contains a naphthenic compound and silicone oil. In this embodiment, the lubricant composition includes a synthetic traction oil and a solid lubricant. For this reason, it is possible to reduce wear between the contact surface and the contacted surface and to suppress slippage between them.

(2) In this embodiment, since the lubricant composition contains a naphthenic compound, it is not necessary to purchase an expensive friction modifier as in Prior Art 1, and the cost can be reduced. The lubricant composition can be easily applied using an oil device. Moreover, in this embodiment, since the lubricant composition contains silicone oil, the friction coefficient can be increased by reducing the force for retaining the oil film.

  In order to examine the application of a lubricant composition capable of transmitting torque under lubrication conditions between the rail and the wheel, a traction characteristic test was conducted on the comparative example and examples 1 and 2.

(Examples 1, 2 and comparative examples)
In Example 1, a reagent containing 90 mass% naphthenic acid as a main component (trade name: naphthenic acid, distributor: Kanto Chemical Co., Ltd.), modified silicone oil (trade name: KF-412, distributor: Shin-Etsu Chemical Co., Ltd.) ) Lubricant composition with 10 mass% added. In Example 2, synthetic traction oil (trade name: KTF-1, distributor: Nissan Motor Co., Ltd.) 99.5 mass%, molybdenum disulfide powder as a solid lubricant (trade name: LIQUI-MOLY, distributor: THE LOCKREY COMPANY) is a lubricant composition to which 0.5 mass% is added. The comparative example is a sample oil that does not take traction characteristics into consideration, and is a normal lubricating oil (trade name: Sinfluid 801, distributor: Nippon Steel Chemical Co., Ltd.) made of 100 mass% polyalphaolefin.

(Traction characteristics test)
Next, the traction characteristics of Examples 1 and 2 and Comparative Example were evaluated using a two-cylinder rolling contact tester. The two-cylinder rolling contact tester is a basic tester designed to explore various wheel / rail contact problems, and measures the traction (tangential force) generated between the wheel disc / rail disc with high accuracy. Can do. The two-cylinder rolling contact tester rotates the wheel disc in a state where the wheel disc and the rail disc, which are made of the same material as the actual product, are in pressure contact with a predetermined load applied, and torque acting on the wheel disc is torqued. Measure with a meter. The test conditions were a peripheral speed of 19 km / h and a maximum Hertz contact pressure of 1 GPa.

(Test results)
FIG. 5 shows the results of traction characteristic tests of Examples 1 and 2 and the comparative example.
The vertical axis shown in FIG. 5 is the traction coefficient, and the horizontal axis is the slip ratio (%). Here, the slip ratio shown in FIG. 5 is a value obtained by dividing the absolute value of the difference between the peripheral speeds of two disks by the peripheral speed of one of the disks. As shown in FIG. 5, Examples 1 and 2 show a higher traction coefficient than the comparative example. Moreover, although the comparative example shows the behavior in which the traction coefficient decreases with an increase in the slip ratio in a slip region of several percent or more, Example 1 shows that the traction coefficient increases with an increase in the slip ratio. It shows a suitable behavior as a lubricating oil. On the other hand, Example 2 has shown the tendency for a traction coefficient to turn from a decrease to an increase. As described above, Examples 1 and 2 may satisfy the necessary traction characteristics, and it is expected to reduce wear between the rail and the wheel. It is thought that it is difficult to cause.

(Other embodiments)
The present invention is not limited to the embodiment described above, and various modifications or changes can be made as described below, and these are also within the scope of the present invention.
(1) In this embodiment, the rail 1 and the wheel 2 have been described as examples of the rail member, but the present invention also applies to other rail members such as pantograph pins and pin bushes that receive frictional resistance by relative motion. Can be applied. Further, in this embodiment, the case where the lubricant composition is supplied to the rail 1 on the outer track side is described as an example, but the lubricant composition can also be supplied to the rail 1 on the inner track side.

(2) In the embodiment of the present invention, the composition of the lubricant composition has been described, but an extreme pressure agent that can withstand a large load can also be added. In this embodiment, the case where the lubricant composition is directly applied has been described as an example. However, the lubricant composition used in the transmission of the vehicle can be appropriately injected from the transmission.

It is a top view which shows the state of the member for railroads where the lubricant composition which concerns on embodiment of this invention is used. It is a front view which expands and shows the II part of FIG. It is the side view seen from the III direction of FIG. It is a figure which shows an ideal traction characteristic. It is a result of the traction characteristic test of Examples 1, 2 and a comparative example.

Explanation of symbols

1 Rail (Railway materials)
1a Parietal surface 1b Inner parietal surface (contact surface)
2 wheels (railway components)
2a Tread surface 2b Flange surface (contacted surface)

Claims (1)

A lubricant composition that reduces wear between a flange surface of a wheel of the railcar and an inner parietal surface of the rail when the railcar passes a sharp curve, and suppresses slippage between them,
In a slip region where a macroscopic slip that leads to idling or sliding due to acceleration or deceleration of the railway vehicle is shown, the traction coefficient increases with an increase in the slip rate,
Including a naphthenic compound and a modified silicone oil,
The naphthenic compound is naphthenic acid,
The modified silicone oil is an alkyl-modified silicone oil ,
The blending ratio of the alkyl- modified silicone oil is 1 to 30 mass%,
A lubricant composition characterized by the above.

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