JP3224270U - Wing rail - Google Patents

Abstract

The present invention provides a wing rail that uses an in-line head-hardening heat-treated rail and can be manufactured while ensuring improved quality without subjecting a head-forging and forging step. In an arbitrary position of the in-line head curing heat treatment rail, the rail abdomen and bottom except for the rail head are heated to about 900 ° C. and then pushed up with a 1/40 twist and a step in the height direction. Let it be the wing rail 3 provided with the compound forge part 5 which bent and deform | transformed simultaneously. [Selection] Figure 1

Description

  The present invention relates to a wing rail that constitutes a crossing rail used at a branch point of a railway track, and more particularly to a wing rail structure that can be manufactured using an in-line head-hardening heat-treated rail.

In a general track of a railroad track, the left and right rails on which the wheels of the vehicle travel are such that the wheels are in stable contact with the rails without shifting laterally when the vehicle is traveling or passing, and the wheel surface and rail surface In order to reduce the pressure applied to the surfaces of each other by increasing the contact area with each other, they are laid at an inward tilt of 1/40.
On the other hand, because the rail crossing portion in the crossing portion where the rail branches cannot be inclined due to its structure, the rail constituting the crossing portion is connected to the front end side of the wing rail connected to the general track. It is necessary to add a 1/40 twist on the rear end side of the nose rail to connect to the general track.

  Further, as shown in FIG. 9, the wheel 2 passing through the crossing unit 1 transfers from the nose rail 4 to the wing rail 3 (and vice versa). At that time, since the shape of the wheel 2 is inclined, the height of the tread surface portion 3 a of the wing rail 3 needs to be higher than that of the nose rail 4.

That is, as shown in FIG. 10, a 1/40 twist is applied to the wing rail 3 at the end of the rail (the twisted portion 6 is provided), and the rail head is raised at the center of the rail 3 (the raised portion). 7 is provided to form the tread surface portion 3a), and the height dimension is secured in order to contact the wheel 2.
As a method for raising the rail head, a method called head forging is performed in which the rail head is heated to about 1100 ° C. and then pressed by a die from the lateral direction to raise the rail head.

Until now, when manufacturing the wing rail 3 used for a crossing part, the following processes were performed.
That is, as shown in FIGS. 10 and 11, a twist forging process (step 21) in which the rail end portion of the wing rail 3 is heated to about 900 ° C. and a 1/40 twist is applied and deformed by a press to provide the twist portion 6. ) And the head central forging step (step 22), in which the head is deformed by pressing from the lateral direction and the raised portion 7 is provided after heating the central portion of the rail to about 1100 ° C., and only the head is raised to about 1000 ° C. A quenching process for heating and quenching (step 23), a distortion correcting process for correcting the distortion of the rail (step 24), and cutting into the shape of the wing rail (step 25) are performed.

In the head forge forging step, as shown in FIG. 10, after heating over the entire range of the wheel transfer portion, the head forging of the rail is performed to form the raised portion 7.
In the quenching process, the hardness of the rail head can be increased by quenching.
In recent years, a head-hardening heat-treated rail that has been hardened in the manufacturing stage has been developed. If this head hardening heat treatment rail can be used for the wing rail of the crossing part, the above-described quenching step can be omitted.

  However, in the manufacturing method described above, when the head-cured heat-treated rail is used instead of simply the HC rail “high carbon rail: NHH (non-heat treated rail of NHH (rail by in-line heat treatment method) and carbon content is 0.78%”, The phenomenon of lowering the hardness of the rail head due to heating such as head raised forging occurs, and no effect can be expected even if the head-hardened heat-treated rail is used. Therefore, it is necessary to perform a quenching process again, and there is a problem that the meaning of using the head-hardening heat-treated rail is lost.

  The present invention has been proposed in view of the above circumstances, and an object thereof is to provide a structure of a wing rail that can be manufactured while ensuring improvement in quality without performing a head forging and quenching process.

In order to achieve the above object, the present invention uses an inline head-hardening heat-treated rail manufactured in a steel mill rolling line as a wing rail, so that any desired wing rail can be used without affecting the hardness of the head-hardening part. At the same time as adding a twist to the position, simultaneous forging is performed with a step in the height direction and pushing up to obtain a wing rail with a desired quality.
That is, the wing rail according to claim 1 has a step in the twist and height direction after heating the rail abdomen and bottom excluding the rail head to about 900 ° C. at any position of the in-line head curing heat treatment rail. It is characterized in that it has a composite forged part that is deformed by simultaneously performing vertical bending to be pushed up.

Claim 2 is the wing rail of claim 1,
The composite forged part (5) arranges the rail so that the head part and the base part of the rail (wing rail 3) are in a side surface position,
When the head side and the base side are sandwiched between a pair of sheet piles (41, 42) (43, 44) with a rail interval, respectively, and pressed from above by a press machine,
Each sheet pile (41, 42, 43, 44) has a wedge shape in which the upper side is longer than the lower side, and the lengths (a, b, c, d) of the upper sides of each sheet pile are all different. Thus, the twisting and longitudinal bending are performed simultaneously.

  According to a third aspect of the present invention, in the wing rail of the first aspect, the in-line head hardening heat-treated rail is a hypereutectoid rail.

  According to a fourth aspect of the present invention, in the wing rail of the third aspect, the hypereutectoid rail has a carbon content of 0.9% or more.

  According to a fifth aspect of the present invention, in the wing rail of the first aspect, the composite forged portion (5) has a deformation range within 150 mm.

According to the present invention, when the vertical bending is performed at the twist position in the height direction, only the abdomen and bottom of the rail are heated to about 900 ° C., which is different from the head forging and raising process in which the entire rail is heated. Since the range is limited, the heating range can be significantly narrowed compared to conventional methods. As a result, it is possible to prevent the hardened portion of the rail head due to the rail heating, and to obtain a wing rail with good quality.
In particular, it is possible to perform processing without crushing the head of the rail (wing rail 3) and without shifting the center of gravity of the rail by performing vertical bending that pushes up with a step.
Moreover, since the rail temperature of a transfer part will not change if the compound forging position is moved away from the wheel transfer part of the wing rail (the part to which the impact from the wheel is applied most), the rail quality does not deteriorate at all at the transfer part.

  In this way, by performing composite forging at an arbitrary position, it is possible to obtain a predetermined high-quality wing rail by omitting the conventional head-raising forging process and quenching process.

  In addition, by setting the composite forging range to 150 mm or less, the composite forged range fits within the sleepers laid between the crossings at a gap interval of 150 to 200 mm. By laying, the bottom surfaces of the front and rear rails that have been forged by compound can be brought into close contact with the sleepers. Thereby, a wing rail does not shake by passage of vehicles.

The wing rail of this invention is shown, (a) is plane explanatory drawing, (b) is side explanatory drawing. It is process drawing for demonstrating the manufacturing method of the wing rail of this invention. It is plane explanatory drawing which shows the structure of a crossing part. FIG. 4 is a cross-sectional explanatory view showing an AA cross section (dotted line) and a BB cross section (solid line) in FIG. 3. It is plane explanatory drawing which shows arrangement | positioning of the metal mold | die with respect to a rail when forming a composite forge part. FIG. 6 is a cross-sectional explanatory view showing a CC cross section in FIG. 5. FIG. 6 is a cross-sectional explanatory view showing a DD cross section in FIG. 5. It is the graph which showed the grade of the heating temperature in the pearlite structure | tissue which comprises a rail, and the fall of hardness. It is sectional explanatory drawing for demonstrating the positional relationship of the wing rail with respect to a wheel at the time of a wheel passing in a crossing part, and a nose rail. It is side surface explanatory drawing of the wing rail manufactured with the conventional manufacturing method. It is process drawing for demonstrating the manufacturing method of the conventional wing rail.

An example according to the embodiment of the wing rail of the present invention will be described with reference to FIGS.
The wing rails 3 are a pair of rails used at the center position of the crossing portion 1 as shown in FIG. 3, and in the present invention, the wing rails 3 are manufactured by composite forging of in-line head hardening heat treatment rails.

The wing rail 3 is bent at a position of about 1/3 in the rail length direction (FIGS. 1A and 3), and as shown in FIGS. 1A and 3, about 2 in the length direction. The tip end side on the / 3 side is configured so as to be arranged along the nose rail 4 in parallel.
Moreover, the wing rail 3 has the composite forge part 5 (FIG. 1 (a) and FIG. 3) in which 1/40 twist and longitudinal bending shown in FIG. 4 are formed simultaneously. The composite forged portion 5 is deformed by heating the rail abdomen and the bottom to about 900 ° C., and performing twisting and vertical bending by simultaneous forging. That is, as shown in FIG. 4, a 1/40 twist and a vertical bending that pushes up with a step in the height direction are simultaneously performed, and the bottom of the wing rail 3 facing the nose rail 4 is pushed upward toward the wing rail 3. Thus, as shown in FIG. 1B, the entire wing rail is raised. Thus, the same dimension as the raised part 7 (FIG. 10) by the conventional head forge raising process can be ensured by the longitudinal bending which added 1/40 twist with respect to the nose rail 4. FIG.

  As shown in FIGS. 5 to 7, the composite forged portion 5 obtained by simultaneously performing a 1/40 twist and a vertical bending with a step in the height direction and pushing it up, includes an upper die 31 and a lower die 32 around the rail. , Sheet piles 41 to 44 are installed and pressed by a press to deform the rail. That is, the rails are laid down in a forged formwork, and the upper mold 31 and the lower mold 32 are set so that the arranged rails are sandwiched from above and below. Four types of sheet piles 41, 42, 43, 44 are set on the head side and the base side, which are the side positions of the arranged rails, and are pushed in from above by a press machine. The four types of sheet piles 41, 42, 43, 44 are each formed in a wedge-shaped cross section whose upper side is longer than the lower side, and a rail corresponding to the length of the composite forged portion 5 sandwiched between the pair of sheet pile 41 and sheet pile 42. The rail is sandwiched between the pair of sheet piles 43 and 44 at intervals.

  The sheet piles 41, 42, 43, and 44 have the same gradient, but the lengths a, b, c, and d of each upper side have a relationship of a <d <c <b. By setting the lengths of the upper sides (lower sides) of the sheet piles 41, 42, 43, and 44 to be different, the step and the twist can be processed simultaneously during the pressing process.

As a result of this press treatment, the composite forged portion 5 having a step of 5 mm on the left and right of the mold can be obtained by deforming the rail.
And by adding a step so as to push up in the height direction as shown in FIG. 4, it is possible to secure the same height dimension as the head forging, and there is no need to crush the rail head, so the head width is reduced. It is possible to leave a wide range and process without decentering the position of the center of gravity.

  The composite forged portion 5 has a width (black portion in FIG. 3) of 150 mm or less in the rail length direction. This is because when the composite forging portion 5 is within 150 mm, the range of the composite forging is accommodated in the crossing portion between the sleepers laid with a gap interval of 150 to 200 mm. By laying the floor plate, the rail fore and aft of the forged rails can be brought into close contact with the sleepers. Thereby, a wing rail does not shake by passage of vehicles.

Then, the manufacturing method of the wing rail mentioned above is demonstrated, referring FIG.
First, the rail abdomen and bottom of the HE rail (product name of Nippon Steel Co., Ltd .: hypereutectoid rail with a carbon content of 0.9% or more) subjected to in-line head hardening heat treatment as a heating process is about 900 ° C. Heat with a burner (step 11). The HE rail has a particularly high hardness among the in-line head-cured heat-treated rails, and the Shore hardness of the top surface of the HE rail is 47 to 56 degrees.
In addition, when heating, the bottom of the rail and the head are coated with refractory clay for heat insulation so that the flame of the burner does not directly hit the rail head. In addition, the temperature of the rail top surface is measured and managed so as not to exceed 400 ° C. If it is likely to exceed, the rail top surface is cooled with compressed air or the like.

The Shore hardness of the top surface of the in-line head curing heat treatment rail is 47 to 56 degrees. This variation in hardness is determined by the amount of alloy elements of the rail itself and the heat treatment method, but the metal structure is a pearlite structure. As shown in FIG. 8, the degree of decrease in heating temperature and hardness in the pearlite structure is not significantly affected at 400 to 500 ° C.
Therefore, if the rail head top surface temperature in contact with the wheels does not exceed 400 ° C., the head top surface hardness of the in-line head hardened heat-treated rail is hardly lowered.

Subsequently, the heated part (heating part) in the in-line head curing heat treatment rail is put into a mold and forged with a press (step 12).
In this process, a composite forging is performed in which a 1/40 twist and a vertical bending that pushes up with a step in the height direction are simultaneously performed (composite forging process).

  Subsequently, an annealing process is performed.

Next, the distortion generated in the wing rail is corrected (step 13).
Finally, the process which bends a wing rail in the position of about 1/3 of a length direction is performed (step 14).

According to the manufacturing method described above, the heating range in the in-line head hardening heat treatment rail does not cover the entire transfer part of the wing rail 3 as in the conventional head forging and raising process, and only the composite forging part 5 within 150 mm. Thus, the working efficiency of the forging process can be improved and the working time can be shortened.
Further, since the in-line head curing heat treatment rail can be used as it is as the wing rail 3, a quenching process is not required, and the wing rail 3 having a low cost and a stable quality can be manufactured.

  DESCRIPTION OF SYMBOLS 1 ... Crossing part, 2 ... Wheel, 3 ... Wing rail, 4 ... Nose rail, 5 ... Compound forging part, 6 ... Twist part, 7 ... Raising part, 31 ... Upper mold, 32 ... Lower mold, 41, 42, 43 44. Sheet pile.

Claims (5)

  At any position on the in-line head curing heat treatment rail, after heating the rail abdomen and bottom, excluding the rail head, to about 900 ° C, it is deformed by twisting and vertically bending with a step in the height direction at the same time. Wing rail characterized by having a combined forged part. The composite forged part arranges the rail so that the head part and the base part of the rail are in a side surface position,
When pressing the head side and the base side from above with a press between the pair of sheet piles with a gap between the rails,
Each sheet pile is formed in a wedge shape having a longer upper side than the lower side, and is formed by simultaneously performing the twisting and vertical bending by setting the lengths of the upper sides of each sheet pile to be different. Wing rail as described.   The wing rail according to claim 1, wherein the in-line head hardening heat-treated rail is a hypereutectoid rail.   The wing rail according to claim 3, wherein the hypereutectoid rail has a carbon content of 0.9% or more.   The wing rail according to claim 1, wherein a range of deformation of the composite forged portion is within 150 mm.

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