JP7485305B2 - Rail fastening device and rail fastening method - Google Patents

Description

The present invention relates to a rail fastening device and rail fastening method for fastening a rail to a support body.

For example, a screw-type rail fastening device is used to fasten a rail to a support such as a sleeper, and the device fastens the rail to the support using a leaf spring, which is a spring member, and a bolt and nut fastener consisting of a male thread included in a shaft member and a female thread formed on the top surface of the support.

Japanese Utility Model Application Publication No. 3-89701 (Patent Document 1) discloses a technology for a leaf spring for a PC fastening device for elastically fastening rails used in a concrete sleeper support, in which part of the center of the leaf width of the leaf spring in the portion that directly contacts the top surface and side surface of the rail bottom is perforated in contiguous relation to the long diameter side of the hole for the fastening bolt.

JP 2004-300691 A (Patent Document 2) discloses a technology for a rail fastening device that fastens a rail to a support, which includes a fastening spring that presses down on the rail to fasten it, and a fastening member that tightens the fastening spring, and which includes a first spherical portion between the fastening spring and the fastening member, and a second spherical portion that contacts the first spherical portion.

Japanese Utility Model Application Publication No. 3-89701 JP 2004-300691 A

In recent years, screwless rail fastening devices have come to be used in place of the screw-type rail fastening devices described above. When using screwless rail fastening devices, there is no need to maintain the bolt and nut fasteners to prevent them from loosening after the rail is fastened to the support body. This means that maintenance work can be reduced and costs can be reduced while still providing the required performance, compared to when using screw-type rail fastening devices that require maintenance to prevent the bolt and nut fasteners from loosening.

However, when changing from a screw-tightened rail fastening device to a screwless rail fastening device, it is necessary to replace the existing bearing (rail bearing) with a bearing such as a PC (Prestressed Concrete) sleeper equipped with a dedicated fastening mechanism, or to embed a dedicated insert in the existing bearing. For this reason, it was not easy to change from a screw-tightened rail fastening device to a screwless rail fastening device.

The present invention has been made to solve the problems of the conventional technology as described above, and aims to provide a rail fastening device that fastens rails without the need to replace the existing support body or embed a dedicated insert in the existing support body, and that can be easily changed from a screw-tightened rail fastening device to a screwless rail fastening device.

The following is a brief summary of the representative inventions disclosed in this application.

A rail fastening device according to one aspect of the present invention is a rail fastening device for fastening a rail to a support. The rail fastening device includes a shaft member having a shaft portion and a head portion, and fixed to the support at the side of the rail with the head portion disposed above the shaft portion; a spring member disposed between the support and the head portion and elastically deformable in the vertical direction; and a frame member having a first upper surface and a first lower surface and a frame portion having a C-shape, U-shape, or U-shape in a top view, and inserted between the spring member and the head portion so that the frame portion surrounds the shaft portion in a top view. The shaft member includes a first spherical portion formed between the shaft portion and the head portion, and the spring member includes a pressing portion that presses against the bottom of the rail. The frame member includes a second spherical portion formed on the first upper surface of the frame portion and capable of engaging with the first spherical portion, and two tapered portions that are connected to both ends of the frame portion, and each of which has a first thickness in the vertical direction that decreases with distance from the center of the frame portion. In addition, the rail fastening device fastens the rail to the support by inserting a frame member between the spring member and the head so that the second spherical portion fits into the first spherical portion, and pressing the bottom portion with the pressing portion.

In another embodiment, the spring member includes a through hole that passes through the spring member in the vertical direction, the minimum inner diameter of the through hole is larger than the maximum outer diameter of both the head and the first spherical portion, and the frame member may be engaged with the peripheral portion of the through hole in the spring member.

In another embodiment, the second lower surface of each of the two tapered portions may be flush with the first lower surface, and the second upper surface of each of the two tapered portions may be inclined with respect to the first upper surface such that the first thickness decreases with increasing distance from the center of the frame portion.

In another embodiment, each of the two tapered portions may be spaced apart from the second spherical portion.

In another embodiment, the tip of each of the two tapered portions may have an arc shape centered on the center of the frame portion when viewed from above.

In another embodiment, the frame portion has a first side surface that is disposed on the opposite side of the two tapered portions across the center of the frame portion when viewed from above, and the first side surface may be flat.

In another embodiment, the second spherical portion may be integrally formed from a first end portion at one of the two ends to a second end portion at the other of the two ends.

In another embodiment, a hole may be formed in the upper surface of the portion of the support that is arranged to the side of the rail, a spiral groove may be formed on the inner peripheral surface of the hole, and the shaft member may be fixed to the support on the side of the rail by inserting the shaft into the hole with the head positioned above the shaft, and bonding the shaft inserted into the hole and embedding it in the hole.

In another embodiment, the shaft portion is a threaded portion that can be screwed into a helical groove formed on the inner circumferential surface of the hole portion, and the shaft member is fixed to the support body on the side of the rail by screwing the threaded portion into the helical groove with the head positioned above the threaded portion, and by gluing and embedding the threaded portion that is screwed into the helical groove into the hole portion.

A rail fastening method according to one aspect of the present invention is a rail fastening method for fastening a first rail to a support. The rail fastening method includes the steps of (a) fixing a first shaft member including a shaft portion and a first head to the support at the side of the first rail with the first head disposed above the shaft portion, (b) disposing a first spring member that elastically deforms in the vertical direction between the support and the first head, and (c) inserting a frame member including a frame portion having a first upper surface and a first lower surface and having a C-shape, U-shape, or U-shape in top view between the first spring member and the first head so that the frame portion surrounds the shaft portion in top view. The first shaft member includes a first spherical portion formed between the shaft portion and the first head, and the first spring member includes a first pressing portion that presses a first bottom portion of the first rail. The frame member includes a second spherical portion formed on the first upper surface of the frame portion and capable of engaging with the first spherical portion, and two tapered portions connected to both ends of the frame portion, each having a first thickness in the vertical direction that decreases with distance from the center of the frame portion. In step (c), the frame member is inserted between the first spring member and the first head portion so that the second spherical portion engages with the first spherical portion, and the first bottom portion is pressed by the first pressing portion, thereby fastening the first rail to the support.

In another embodiment, in step (c), two tapered portions are inserted between the first spring member and the first head with the shaft portion sandwiched between the two tapered portions when viewed from above, and the frame member is pushed and moved between the first spring member and the first head from the state in which the two tapered portions are inserted between the first spring member and the first head to a state in which a frame portion is inserted between the first spring member and the first head and the second spherical portion is engaged with the first spherical portion, and the first pressing portion presses the first bottom portion with the second spherical portion engaged with the first spherical portion, thereby fastening the first rail to the support.

In another embodiment, a hole may be formed on the upper surface of the portion of the support that is disposed to the side of the first rail, and a spiral groove may be formed on the inner peripheral surface of the hole. The rail fastening method may further include a step (d) of removing a second shaft member including a threaded portion and a second head, the second head being disposed above the threaded portion, and a second spring member including a second pressing portion that presses a second bottom portion of the second rail being disposed between the support and the second head, the threaded portion being screwed into the spiral groove, the second pressing portion being pressed by the second head included in the second shaft member screwed into the spiral groove, and the second bottom portion being pressed by the second pressing portion pressed by the second head, thereby fastening the second rail to the support, and a step (e) of removing the second spring member after the step (d) and before the step (a). In step (a), the first shaft member may be fixed to the support on the side of the first rail by inserting the shaft into the hole with the first head positioned above the shaft and gluing the inserted shaft into the hole to embed it therein.

In another embodiment, the first spring member arranged between the support and the first head in step (b) may include a first elastic plate extending in the width direction of the first rail, a second elastic plate arranged above the first elastic plate and extending in the width direction of the first rail, and a third elastic plate connecting the first elastic plate opposite the center side of the first rail in the width direction of the first rail and the second elastic plate opposite the center side of the first rail in the width direction of the first rail. The first pressing portion included in the first spring member arranged between the support and the first head in step (b) may be the tip of the second elastic plate on the center side of the first rail in the width direction of the first rail. The second elastic plate included in the first spring member arranged between the support and the first head in step (b) may include a plate-shaped portion inclined so that the height position becomes lower as it moves away from the center of the first rail in the width direction of the first rail. In step (b), the first pressing portion included in the first spring member disposed between the support and the first head may be spaced apart from the first bottom. In step (c), after step (b), in a state in which the plate-shaped portion included in the second elastic plate is inclined so that its height position decreases with increasing distance from the center of the first rail in the width direction of the first rail and the first pressing portion is spaced apart from the first bottom, a frame member may be inserted between the second elastic plate and the first head, the frame member inserted between the second elastic plate and the first head presses the first pressing portion downward, and the first pressing portion pressed downward presses the first bottom, thereby fastening the first rail to the support. The second thickness in the vertical direction of each of the two tapered portions may be thinner than the first vertical distance between the first portion, which is the first portion of the second elastic plate portion before the frame member is inserted in step (c), and the second portion, which is the peripheral portion of the first spherical portion opposite the center side of the first rail in the width direction of the first rail, and the first portion located directly below the second portion.

By applying one aspect of the present invention, in a rail fastening device that fastens a rail, there is no need to replace the existing support body, and there is no need to embed a dedicated insert in the existing support body, and it is possible to easily change from a screw-tightened rail fastening device to a screwless rail fastening device.

FIG. 2 is a top view showing the rail fastening device of the first embodiment. 1 is a cross-sectional view showing a rail fastening device according to a first embodiment. FIG. 2 is a side view showing a shaft member of the rail fastening device of the first embodiment. 3A and 3B are top and cross-sectional views showing a spring member of the rail fastening device of embodiment 1. 2A and 2B are top and cross-sectional views showing a frame member of the rail fastening device of embodiment 1. FIG. 11 is a top view showing a rail fastening device of a comparative example. FIG. 4 is a cross-sectional view showing a rail fastening device of a comparative example. FIG. 11 is a flow diagram showing a part of a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2. A cross-sectional view showing a rail fastening process in embodiment 2.

Each embodiment of the present invention will be described below with reference to the drawings.

Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive of while maintaining the gist of the invention are naturally included within the scope of the present invention. In addition, in order to make the explanation clearer, the drawings may show the width, thickness, shape, etc. of each part diagrammatically compared to the embodiment, but these are merely examples and do not limit the interpretation of the present invention.

In addition, in this specification and each figure, elements similar to those previously described with respect to the previous figures are given the same reference numerals, and detailed descriptions may be omitted as appropriate.

Furthermore, in the drawings used in the embodiments, hatching (shading) may be omitted even in cross-sectional views to make the drawings easier to read. Hatching may also be added even in plan views to make the drawings easier to read.

In the following embodiments, when a range is indicated as A to B, it means A or more and B or less unless otherwise specified.

(Embodiment 1)
<Rail fastening device>
A rail fastening device according to a first embodiment of the present invention will be described in comparison with a rail fastening device of a comparative example.

Figure 1 is a top view showing the rail fastening device of the first embodiment. Figure 2 is a cross-sectional view showing the rail fastening device of the first embodiment. Figure 3 is a side view showing the shaft member of the rail fastening device of the first embodiment. Figure 4 is a top view and a cross-sectional view showing the spring member of the rail fastening device of the first embodiment. Figure 4(a) shows a top view, and Figure 4(b) shows a cross-sectional view. Figure 5 is a top view and a cross-sectional view showing the frame member of the rail fastening device of the first embodiment. Figure 5(a) shows a top view, and Figure 5(b) shows a side view. Note that in the cross-sectional view shown in Figure 2, a side view of the spring member and embedded plug is shown on the left side of the rail, and a cross-sectional view of the spring member and embedded plug is shown on the right side of the rail.

Figure 6 is a top view showing a rail fastening device of a comparative example. Figure 7 is a cross-sectional view showing a rail fastening device of a comparative example. Note that in the cross-sectional view shown in Figure 7, the left side of the rail shows a side view of the spring member and embedded plug, and the right side of the rail shows a cross-sectional view of the spring member and embedded plug.

As shown in Figures 1 to 5, the rail fastening device 1 of the present embodiment 1 is a rail fastening device that fastens a rail 3 to a support body 2 that supports the rail. In the rail fastening device 1 of the present embodiment 1, the rail 3 is fastened to the support body 2 by the rail fastening method of the embodiment 2 described below. In addition, the rail fastening device 1 of the present embodiment 1 is a direct-connection type rail fastening device that directly fastens the rail 3 to the support body 2, and has a cushioning function that absorbs vibrations that occur when a train passes through.

The rail 3 is a member that supports and guides the wheels of a railway vehicle to allow the railway vehicle to run. The rail 3 includes a rail head 3a that contacts the wheels of the railway vehicle, a rail bottom 3b as the bottom part that is attached to the support body 2, and a rail web part 3c that connects the rail head 3a and the rail bottom 3b. The support body 2 is a member that supports the rail 3. For example, existing sleepers such as prestressed concrete (PC) sleepers can be used as the support body 2.

The rail fastening device 1 of this embodiment 1 has a shaft member 4, a spring member 5 also called a fastening spring, and a frame member 6, which is a type of washer. Details of the shaft member 4, the spring member 5, and the frame member 6 will be described later.

A track pad 7 is inserted between the support body 2 and the rail 3. The track pad 7 is an elastic body made of vulcanized rubber or urethane and has a plate-like shape. The track pad 7 has the function of mitigating the impact load generated when a train passes, and the function of ensuring resistance to the longitudinal movement of the rail 3. The track pad 7 also has the function of protecting the surface of the support body 2 and electrically insulating the rail bottom 3b from the support body 2.

A receiving plug 8 is inserted between the support body 2 and the spring member 5. The receiving plug 8 is a member made of resin such as plastic that is embedded in the surface of the support body 2 to support the spring member 5, and has the function of electrically insulating the support body 2 and the spring member 5.

When the support body 2 is an existing sleeper such as a PC sleeper, the embedded plug 9 is embedded in the embedded hole 2a formed on the upper surface of the support body 2. In such a case, the support body 2 is an existing sleeper such as a PC sleeper, with the embedded plug 9 embedded in the embedded hole 2a formed on the upper surface of the sleeper. The embedded plug 9 is made of unsaturated polyester resin or nylon. A hole 9a is formed on the upper surface of the embedded plug 9, and a spiral groove 9b is formed on the inner surface of the hole 9a. Although the details will be described later, the shaft member 4 is embedded in the hole 9a. A spiral iron wire 9c is provided around the embedded plug 9, and a water drainage collar 9d is connected to the lower part of the embedded plug 9. The embedded plug 9 also has the function of electrically insulating the support body 2 and the shaft member 4.

Next, we will explain in detail the shaft member 4, spring member 5, and frame member 6 of the rail fastening device 1 of this embodiment 1.

The shaft member 4 includes a shaft portion 4a and a head portion 4b connected to the shaft portion 4a. The shaft member 4 is fixed to the support body 2 on the side of the rail 3 supported by the support body 2 by embedding and fixing the shaft portion 4a in a portion of the support body 2 that is disposed to the side of the rail 3, with the head portion 4b disposed above the shaft portion 4a and the head portion 4b disposed (protruding) above the support body 2.

As described above, the bearing 2 may be one in which the plug 9 is embedded in the hole 2a formed in the upper surface of an existing sleeper such as a PC sleeper. In this case, the plug 9 has a hole 9a formed in the upper surface, and the hole 9a has a spiral groove 9b formed in the inner peripheral surface. Therefore, the bearing 2 may be one in which the hole 9a is formed in the upper surface of the part of the bearing 2 arranged to the side of the rail 3, and the hole 9a has a spiral groove 9b, i.e., a female thread, formed in the inner peripheral surface. In this case, the shaft member 4 is fixed to the bearing 2 by inserting the shaft portion 4a into the hole 9a with the head portion 4b arranged above the shaft portion 4a and the head portion 4b arranged above the bearing 2, and the shaft portion 4a inserted into the hole 9a is bonded to the hole 9a with adhesive GL1, embedded, and fixed to the bearing 2. Although only a portion of the adhesive GL1 is shown in FIG. 2, the adhesive GL1 may be present between the shaft portion 4a and the spiral groove 9b throughout the entire hole portion 9a.

As described above, the shaft member 4 is fixed to the support body 2 by embedding the shaft portion 4a in the support body 2, and the method of fixing the shaft member 4 to the support body 2 does not have to be by adhesion and is not particularly limited. Therefore, the shaft portion 4a may be a threaded portion, i.e. a male screw, that can be screwed into the spiral groove 9b formed on the inner surface of the hole portion 9a, but it does not have to be a threaded portion. However, when the shaft portion 4a is a threaded portion, the shaft member 4 is fixed to the support body 2 on the side of the rail 3 supported by the support body 2 by screwing the threaded portion into the spiral groove 9b with the head portion 4b arranged above the threaded portion and the head portion 4b arranged above the support body 2, and the threaded portion screwed into the spiral groove 9b is glued to the hole portion 9a, embedded, and fixed to the support body 2. In this case, the adhesive surface area can be increased compared to when the shaft portion 4a is not a threaded portion, so the shaft portion 4a can be more firmly adhered and embedded, and the shaft portion 4a can be more firmly fixed.

The spring member 5 is disposed between the support body 2 and the head portion 4b, and is elastically deformable in the vertical direction. The spring member 5 also includes a pressing portion 5a that presses against the rail bottom portion 3b of the rail 3. The spring member 5 is also called a fastening spring.

The spring member 5 is a spring that presses down on the rail 3 and fastens it. The spring member 5 is a leaf spring formed by bending a plate-shaped spring steel into an approximately U-shape, and functions as a presser, i.e., a spring clip. The spring member 5 includes tip portions 5b and 5c, plate-shaped portions 5d and 5e, and a bent portion 5f. The tip portions 5b and 5c are portions that press down the upper surface of the rail bottom portion 3b by the elastic force of the leaf spring. The tip portion 5b is formed in a hook shape and presses down the upper and side surfaces of the rail bottom portion 3b. The tip portion 5c presses down the tip portion 5b from the upper side and presses down the upper surface of the rail bottom portion 3b. The plate-shaped portions 5d and 5e are flat portions formed in a plate shape. The plate-shaped portions 5d and 5e have through holes (long holes) 5g and 5h whose hole diameter in the width direction of the rail 3 is longer than the hole diameter in the length direction of the rail 3. The bent portion 5f is an end portion formed by bending the spring steel into an approximately U-shape.

In other words, the spring member 5 may include an elastic plate portion 11, an elastic plate portion 12, and an elastic plate portion 13. The elastic plate portion 11 is made of a tip portion 5b and a plate-shaped portion 5d, and extends in the width direction of the rail 3. The elastic plate portion 12 is made of a tip portion 5c and a plate-shaped portion 5e, and is disposed above the elastic plate portion 11 and extends in the width direction of the rail 3. The elastic plate portion 13 is made of a bent portion 5f, and connects the end portion of the elastic plate portion 11 on the opposite side to the center side of the rail 3 in the width direction of the rail 3 and the end portion of the elastic plate portion 12 on the opposite side to the center side of the rail 3 in the width direction of the rail 3. In this case, the pressing portion 5a is the tip portion of the elastic plate portion 12 on the center side of the rail 3 in the width direction of the rail 3, i.e., the tip portion 5c, or the tip portion of the elastic plate portion 11 on the center side of the rail 3 in the width direction of the rail 3, i.e., the tip portion 5b.

The spring member 5 is not limited to the above example, as long as it is disposed between the support body 2 and the head 4b, elastically deforms in the vertical direction, and includes a pressing portion 5a.

The frame member 6 includes a frame portion 14. The frame portion 14 has an upper surface 14a and a lower surface 14b, and has a C-shape, a U-shape, or a U-shape with a portion cut out in the circumferential direction when viewed from above. The frame member 6 is inserted between the spring member 5 and the head 4b so that the frame portion 14 surrounds the shaft portion 4a when viewed from above.

In other words, the frame portion 14 includes two extension portions 15 that are arranged in the longitudinal direction of the rail 3 with a gap IN1 wider than the outer diameter DM1 of the shaft portion 4a when viewed from above and that each extend in the width direction of the rail 3, and a connection portion 16 that connects two ends EP1 of each of the two extension portions 15, which are the ends opposite the center side of the rail 3 in the width direction of the rail 3.

The shaft member 4 includes a spherical portion 17, and the frame member 6 includes a spherical portion 18 and two tapered portions 19. The spherical portion 17 is formed between the shaft portion 4a and the head portion 4b, and has a spherical shape. The spherical portion 18 is formed on the upper surface 14a of the frame portion 14, and has a spherical shape that can fit with the spherical portion 17. The two tapered portions 19 are connected to two ends EP2, which are both ends of the frame portion 14, respectively, and the thickness in the vertical direction decreases with distance from the center of the frame portion 14. The two tapered portions 19 are also arranged with a gap IN2 wider than the outer diameter DM1 of the shaft portion 4a in the longitudinal direction of the rail 3 when viewed from above.

There is a gap GP1 between the shaft portion 4a and one of the two extension portions 15, and the average value of the two gaps GP1 can be set to a certain lower limit value or more and a certain upper limit value or less. In addition, there is a gap GP2 between the shaft portion 4a and one of the two tapered portions 19, and the average value of the two gaps GP2 can be set to a certain lower limit value or more and a certain upper limit value or less, which is equal to the average value of the gap GP1. When the average value of the gap GP1 and the average value of the gap GP2 are equal to or more than a certain lower limit value, the frame member 6 can be easily inserted between the spring member 5 and the head portion 4b with the two tapered portions 19 sandwiching the shaft portion 4a, and the inserted frame member 6 can be easily pushed in until the shaft portion 4a approaches the connection portion 16, compared to when the average value of the gap GP1 and the average value of the gap GP2 are less than a certain lower limit value. When the average value of the gap GP1 and the average value of the gap GP2 are equal to or less than a certain upper limit, the relative position of the frame member 6 inserted between the spring member 5 and the head 4b to the shaft member 4 in a top view is less likely to shift, compared to when the average value of the gap GP1 and the average value of the gap GP2 exceed a certain upper limit.

In the rail fastening device 1 of the present embodiment 1, the frame member 6 is inserted between the spring member 5 and the head 4b so that the spherical portion 18 fits with the spherical portion 17, the pressing portion 5a is pressed down by the frame member 6 being inserted, and the rail bottom 3b is pressed by the pressed down pressing portion 5a, thereby fastening the rail 3 to the support body 2. In other words, in the rail fastening device 1 of the present embodiment 1, with the spherical portion 18 fitted with the spherical portion 17, the frame member 6 is inserted between the spring member 5 and the head 4b, and the rail bottom 3b is pressed by the pressing portion 5a, thereby fastening the rail 3 to the support body 2.

In the present embodiment 1, an example is given in which the spherical portion 17 is a convex portion having a downwardly convex spherical shape, and the spherical portion 18 is a concave portion having a downwardly convex spherical shape. However, the spherical portion 17 may be a concave portion having an upwardly convex spherical shape, and the spherical portion 18 may be a convex portion having an upwardly convex spherical shape.

On the other hand, as shown in Figures 6 and 7, the rail fastening device 1a of the comparative example is a rail fastening device that fastens the rail 3d to the support body 2, similar to the rail fastening device 1 of embodiment 1, and has an axis member 4c and a spring member 5i, a track pad 7 is inserted between the support body 2 and the rail 3d, a receiving plug 8 is inserted between the support body 2 and the spring member 5, and an embedded plug 9 is embedded in the embedded hole 2a formed on the upper surface of the support body 2. On the other hand, unlike the rail fastening device 1 of embodiment 1, the rail fastening device 1a of the comparative example does not have a frame member 6 (see Figure 2). Also, in the comparative example, the spring member 5i may be different from the spring member 5.

In the comparative example, as in the first embodiment, the shaft member 4c includes a shaft portion 4a and a head portion 4b connected to the shaft portion 4a. However, in the comparative example, unlike the first embodiment, the shaft portion 4a is a threaded portion 4d, i.e., a male screw.

In the comparative example, as in the first embodiment, the bearing 2 is formed by embedding a plug 9 in an embedding hole 2a formed in the upper surface of an existing sleeper, such as a PC sleeper. A hole 9a is formed in the upper surface of the plug 9, and a spiral groove 9b is formed on the inner peripheral surface of the hole 9a. Therefore, the bearing 2 is formed by forming a hole 9a in the upper surface of the bearing 2, and forming a spiral groove 9b, i.e., a female thread, on the inner peripheral surface of the hole 9a. In such a case, the shaft member 4 is fixed to the bearing 2 by screwing the screw portion 4d into the spiral groove 9b with the head 4b positioned above the screw portion 4d.

In the comparative example, as in the first embodiment, the spring member 5i is disposed between the support body 2 and the head 4b, and is elastically deformed in the vertical direction. Also, in the comparative example, as in the first embodiment, the spring member 5i includes a pressing portion 5a that presses against the rail bottom portion 3b of the rail 3d.

In the comparative example, as in the first embodiment, specifically, the spring member 5i may include an elastic plate portion 21, an elastic plate portion 22, and an elastic plate portion 23. The elastic plate portion 21 is made of a tip portion 5b and a plate-shaped portion 5d, and extends in the width direction of the rail 3d. The elastic plate portion 22 is made of a tip portion 5c and a plate-shaped portion 5e, and is disposed above the elastic plate portion 21 and extends in the width direction of the rail 3d. The elastic plate portion 23 is made of a bent portion 5f, and connects the end portion of the elastic plate portion 21 opposite the rail 3d side in the width direction of the rail 3d to the end portion of the elastic plate portion 22 opposite the rail 3d side in the width direction of the rail 3d. In such a case, the pressing portion 5a is the tip portion of the elastic plate portion 22 on the center side of the rail 3d in the width direction of the rail 3d, i.e., the tip portion 5c, or the tip portion of the elastic plate portion 21 on the center side of the rail 3d in the width direction of the rail 3d, i.e., the tip portion 5b. Although through holes 5j and 5k are formed in plate-shaped portions 5d and 5e, unlike through holes (long holes) 5g and 5h (see FIG. 2) in embodiment 1, the diameter of the holes in the width direction of rail 3d is equal to the diameter of the holes in the length direction of rail 3d.

Meanwhile, in the comparative example, unlike the first embodiment, the shaft member 4c does not have a spherical portion 17 (see FIG. 2). Also, in the comparative example, unlike the first embodiment, the head 4b is disposed above the threaded portion 4d, and a spring member 5i including a pressing portion 5a that presses the rail bottom portion 3b of the rail 3d is disposed between the support body 2 and the head 4b. The threaded portion 4d is screwed into the spiral groove 9b, and the head 4b included in the shaft member 4c screwed into the spiral groove 9b presses the pressing portion 5a, and the pressing portion 5a pressed by the head 4b presses the rail bottom portion 3b, thereby fastening the rail 3d to the support body 2.

That is, the rail fastening device 1a of the comparative example is a screw-tightening type rail fastening device that fastens the rail 3d to the support body 2 using a leaf spring as the spring member 5i and a bolt and nut fastener consisting of a male thread included in the shaft member 4c and a female thread formed on the upper surface of the support body 2. In addition, a washer 4e is inserted between the spring member 5i and the head 4b.

Here, we explain the problems with the rail fastening device and rail fastening method that fasten the rail to the support (rail support).

Traditionally, in Japan, screw-type rail fastening devices have been used that fasten the rail to the support using a leaf spring and a bolt and nut fastener, as in the rail fastening device of the comparative example. Meanwhile, in recent years, screwless rail fastening devices that do not use bolt and nut fasteners have come to be used in place of screw-type rail fastening devices that use bolt and nut fasteners. When using screwless rail fastening devices, there is no need to maintain the bolt and nut fasteners to prevent them from loosening after the rail is fastened to the support. Therefore, compared to using screw-type rail fastening devices that require maintenance to prevent the bolt and nut fasteners from loosening, it is possible to reduce the labor and cost of maintenance work while still achieving the specified performance.

However, when changing from a screw-tightened rail fastening device to a screwless rail fastening device, it is necessary to replace the existing support body (rail support body) with a support body such as a PC sleeper that is equipped with a dedicated fastening mechanism, which results in high introduction costs. In this way, the high introduction cost is a factor that inhibits the spread of screwless rail fastening devices. In other words, because it is necessary to replace the existing support body, it is not easy to change from a screw-tightened rail fastening device to a screwless rail fastening device.

As a screwless rail fastening device, for example, a wire spring is used instead of a leaf spring. However, when using a screwless rail fastening device that uses a wire spring, it is necessary to embed a dedicated insert into the existing support body (rail support body). In this way, the need to embed a dedicated insert into the existing support body is a factor that inhibits the spread of screwless rail fastening devices. For this reason, it has not been easy to change from a screw-tightened rail fastening device to a screwless rail fastening device.

On the other hand, the rail fastening device of the present embodiment 1 has a frame member 6 in addition to the shaft member 4 and the spring member 5. The frame member 6 includes a frame portion 14 that has a C-shape, a U-shape, or a U-shape when viewed from above, and is inserted between the spring member 5 and the head portion 4b so that the frame portion 14 surrounds the shaft portion 4a when viewed from above.

In this embodiment 1, unlike the comparative example, the shaft member 4 is fixed to the support body 2 on the side of the rail 3 supported by the support body 2 by embedding and fixing the shaft portion 4a in a portion of the support body 2 that is disposed to the side of the rail 3 with the head portion 4b disposed above the shaft portion 4a. The shaft member 4 also includes a spherical portion 17, and the frame member 6 includes a spherical portion 18 that can be fitted with the spherical portion 17, and two tapered portions 19. The frame member 6 is inserted between the spring member 5 and the head portion 4b so that the spherical portion 18 fits with the spherical portion 17, and the rail bottom portion 3b is pressed by the pressing portion 5a, thereby fastening the rail 3 to the support body 2.

This makes it possible to realize a screwless rail fastening device that utilizes an existing rail support and uses a leaf spring, which is the same spring member as existing rail fastening devices that have excellent fatigue resistance and strength. Also, by modifying the shape of the fastening bolt portion and changing the fastening method of the rail fastening device from a screw-tightening type using a bolt and nut fastener to a screwless fastening type in which a wedge-shaped frame member is inserted (installed) between the spring member and the head of the shaft member, it is possible to easily change from a screw-tightening type rail fastening device to a screwless type rail fastening device.

In other words, according to the first embodiment, in the rail fastening device that fastens the rail, there is no need to replace the existing support body, and there is no need to embed a dedicated insert in the existing support body, and it is possible to easily change from a screw-tightened rail fastening device to a non-screw-tightened rail fastening device.

In addition, existing stock of supports (rail supports) can be used as is without replacement, reducing maintenance costs. In addition, the lack of screw tightening eliminates the need for fastening status management, such as the inevitable loosening and retightening of bolt and nut fasteners, and reduces the labor required for maintenance work.

If the tip of the frame member 6 is not made thin, it is difficult to act as an opening for pushing the frame member 6 when inserting (installing) it between the spring member 5 and the head 4b of the shaft member 4. On the other hand, by having two tapered portions 19, the frame member 6 has a wedge shape when viewed from the side. Therefore, it is easy to act as an opening for pushing the frame member 6 when inserting (installing) it between the spring member 5 and the head 4b of the shaft member 4.

When the shaft member 4 does not include the spherical portion 17 and the frame member 6 does not include the spherical portion 18, the relative position of the frame member 6 to the shaft member 4 in the top view is likely to shift, so that after the rail 3 is fastened to the support 2, the frame member 6 may shift from its predetermined position in the top view, or the spring member 5 may shift from its predetermined position in the top view. On the other hand, when the shaft member 4 includes the spherical portion 17 and the frame member 6 includes the spherical portion 18, the spherical portion 18 fits into the spherical portion 17 to prevent the relative position of the frame member 6 to the shaft member 4 in the top view from shifting, and after the rail 3 is fastened to the support 2, the frame member 6 is prevented from shifting from its predetermined position in the top view, and the spring member 5 is prevented from shifting from its predetermined position in the top view.

In the technology described in Patent Document 2, a first spherical portion and a second spherical portion that contacts the first spherical portion are provided between the fastening spring and the fastening member. However, in the technology described in Patent Document 2, the first spherical portion and the second spherical portion are intended to ensure that the fastening bolt and the washer come into substantially uniform contact at the spherical portion even if the height of the rail is adjusted to change the position of the fastening spring and the washer. Also, in the technology described in Patent Document 2, the first spherical portion and the second spherical portion are intended to fasten the rail to the support body with an appropriate pressing force so that the fastening bolt tightens the fastening spring with a substantially uniform tightening force.

On the other hand, the spherical surface portion 17 and the spherical surface portion 18 in the present embodiment 1 are intended to prevent the position of the frame member 6 from shifting relative to the shaft member 4 when viewed from above by fitting the spherical surface portion 18 into the spherical surface portion 17, and the first spherical surface portion and the second spherical surface portion in the above Patent Document 2 have different purposes.

Preferably, the spring member 5 includes a through hole 5h that penetrates the spring member 5 in the vertical direction, the minimum diameter of the inner diameter DM2 of the through hole 5h is larger than the maximum diameter of the outer diameter DM3 of either the head 4b or the spherical portion 17, and the frame member 6 is engaged with the peripheral portion of the through hole 5h of the spring member 5. Similarly to the through hole 5h, the minimum diameter of the inner diameter of the through hole 5g that penetrates the spring member 5 in the vertical direction is also larger than the maximum diameter of the outer diameter DM3 of either the head 4b or the spherical portion 17. That is, the head 4b and the spherical portion 17 can be inserted through the through holes 5h and 5g. It goes without saying that the outer diameter DM3 is larger than the outer diameter DM1 of the shaft portion 4a, and the shaft portion 4a can be inserted through the through holes 5h and 5g.

Consider a case where the spring member 5 is not fastened by pressing it by screwing in the shaft member 4, for example, where the spring member 5 is placed first, and then the shaft portion 4a is inserted into a hole 9a formed in the upper surface of the portion of the support body 2 that is placed to the side of the rail 3 with the shaft portion 4a passing through the through holes 5h and 5g, and the shaft portion 4a inserted into the hole 9a is glued and embedded, thereby fixing it to the support body 2. In such a case, it is necessary to press the shaft member 4 against the support body 2 while the shaft portion 4a is glued and fixed to the support body 2.

In addition, as the railway vehicle travels on the rail 3, the rail head 3a wears. Therefore, even after the rail fastening device 1 of the present embodiment 1 is installed, the rail 3 needs to be replaced periodically, and it is desirable to make the spring member 5 detachable even after the rail fastening device 1 of the present embodiment 1 is installed.

On the other hand, if the minimum diameter of the inner diameter DM2 of the through holes 5h and 5g is larger than the maximum diameter of the outer diameter DM3 of both the head 4b and the spherical portion 17, as will be described later with reference to Figures 12 and 13, in the rail fastening method of embodiment 2, after the shaft portion 4a is fixed to the support body 2, the spring member 5 can be placed between the support body 2 and the head 4b of the shaft member 4. As a result, even if the spring member 5 is not pressed and fastened by screwing (threading) the shaft member 4, it is not necessary to place the spring member 5 before the shaft portion 4a is fixed to the support body 2, and therefore it is not necessary to press the shaft member 4 against the support body 2 while the shaft portion 4a is being bonded and fixed to the support body 2.

In addition, if the minimum diameter of the inner diameter DM2 of the through holes 5h and 5g is larger than the maximum diameter of the outer diameter DM3 of both the head 4b and the spherical portion 17, the spring member 5 can be made detachable even after the rail fastening device 1 of this embodiment 1 is installed, and the rail 3 can be easily replaced even after the rail fastening device 1 of this embodiment 1 is installed.

Preferably, the upper surface 19a and the lower surface 19b of each of the two tapered portions 19 are inclined with respect to the upper surface 14a such that the lower surface 19b is flush with the lower surface 14b and the upper surface 19a becomes thinner with increasing distance from the center of the frame portion 14.

In this case, the bottom surface of the frame member 6 becomes flat, making it easier to slide the frame member 6 on the spring member 5, i.e., on the elastic plate portion 12 including the plate-shaped portion 5e, and easier to insert, i.e., install, the frame member 6 between the spring member 5 and the head portion 4b of the shaft member 4. This makes it even easier to carry out construction work at the site where the rail 3 is laid.

Preferably, each of the two tapered portions 19 is spaced apart from the spherical portion 18. In this case, even if vibrations are applied to the rail fastening device 1 when the railway vehicle travels on the rail 3, the planar position of the spherical portion 18 engaged with the spherical portion 17 can be reliably prevented or suppressed from shifting in the direction from the tapered portion 19 toward the spherical portion 18 (the direction away from the center of the rail 3 in the width direction of the rail 3), causing the spherical portion 17 to come off the spherical portion 18.

In addition, from the viewpoint of preventing the planar position of the spherical portion 18 from shifting in the direction from the tapered portion 19 toward the spherical portion 18 while easily forming the spherical portion 17, when the lower surface 19b of each of the two tapered portions 19 is flush with the lower surface 14b, it is preferable that the spherical portion 17 is a convex portion having a downwardly convex spherical shape, and the spherical portion 18 is a concave portion having a downwardly convex spherical shape. In addition, from the viewpoint of preventing the spherical portion 17 from coming off the spherical portion 18, it is preferable that the spherical center of the spherical portion 17 overlaps with the shaft portion 4a when viewed from above, that is, the spherical portion 17 has a shape that is approximately symmetrical with respect to the shaft portion 4a.

Preferably, the tip of each of the two tapered portions 19 on the side opposite the frame portion 14 (the side toward the center of the rail 3 in the width direction of the rail 3) has an arc shape centered on the center of the frame portion 14 when viewed from above. In such a case, the tip of one tapered portion 19 on the side opposite the frame portion 14 protrudes further toward the side opposite the frame portion 14 than the side opposite the other tapered portion 19. This makes it easier to insert, i.e., install, the frame member 6 between the spring member 5 and the head 4b of the shaft member 4, compared to when the tip of one tapered portion 19 on the side opposite the other tapered portion 19 protrudes further toward the side opposite the frame portion 14 than the side opposite the other tapered portion 19.

Preferably, the frame portion 14 has a side surface 14c arranged on the opposite side of the two tapered portions 19 across the center of the frame portion 14 on the opposite side of the center of the rail 3 in the width direction of the rail 3 in a top view, and the side surface 14c is a plane that intersects, preferably perpendicular to, the width direction of the rail 3. In this case, the frame portion 14 has a U-shape with the center side of the rail 3 in the width direction of the rail 3 open in a top view.

In this case, since the side surface 14c is flat, the frame member 6 can be easily inserted between the spring member 5 and the head 4b of the shaft member 4 by hitting the side surface 14c of the frame portion 14 with a hammer or the like.

Preferably, the spherical portion 18 is integrally formed from one end EP2 of both ends to the other end EP2 of both ends. In this case, the frame portion 14 and the spherical portion 18 have a C-shape or U-shape with a portion of the circumferential direction cut out on the center side of the rail 3 in the width direction of the rail 3 when viewed from above.

In such a case, the area of the spherical portion 18 can be increased, so that the planar position of the spherical portion 17 fitted into the spherical portion 18 can be shifted, and the spherical portion 17 can be reliably prevented or suppressed from coming off the spherical portion 18.

(Embodiment 2)
<Rail fastening method>
Next, a rail fastening method according to the second embodiment will be described. The rail fastening method according to the second embodiment is a rail fastening method for fastening a rail to a support body that supports the rail. As described above, the rail fastening device in which the rail is fastened to the support body by the rail fastening method according to the second embodiment is the rail fastening device according to the first embodiment.

Figure 8 is a flow diagram showing a part of the rail fastening process of embodiment 2. Figures 9 to 14 are cross-sectional views showing the rail fastening process of embodiment 2. Note that, like the cross-sectional view shown in Figure 2, the cross-sectional views shown in Figures 9 to 14 show a side view of the spring member and embedded plug on the left side of the rail, and a cross-sectional view of the spring member and embedded plug on the right side of the rail.

Before the rail fastening method of the second embodiment is performed, the rail fastening device 1a of the comparative example described with reference to FIG. 7 is used. That is, the head 4b of the shaft member 4c including the screw portion 4d and the head 4b connected to the screw portion 4d is arranged above the screw portion 4d, the head 4b is arranged above the support body 2, and a spring member 5i including a pressing portion 5a that presses the rail bottom portion 3b of the rail 3d is arranged between the support body 2 and the head 4b. In this state, the screw portion 4d is screwed into the spiral groove 9b, the head 4b included in the shaft member 4c screwed into the spiral groove 9b presses the pressing portion 5a, and the pressing portion 5a pressed by the head 4b presses the rail bottom portion 3b, thereby fastening the rail 3d to the support body 2.

Note that rail 3d may be the same rail as rail 3, but rail 3d may be a rail different from rail 3. If rail 3d is a rail different from rail 3, the rails will be swapped between steps S2 and S3, which will be described later.

As described above, the spring member 5i may include an elastic plate portion 21, an elastic plate portion 22, and an elastic plate portion 23. The elastic plate portion 21 extends in the width direction of the rail 3d. The elastic plate portion 22 is disposed above the elastic plate portion 21 and extends in the width direction of the rail 3d. The elastic plate portion 23 connects the end portion of the elastic plate portion 21 on the opposite side to the center side of the rail 3d in the width direction of the rail 3d and the end portion of the elastic plate portion 22 on the opposite side to the center side of the rail 3d in the width direction of the rail 3d. In this case, the pressing portion 5a is the tip portion of the elastic plate portion 22 on the center side of the rail 3d in the width direction of the rail 3d, i.e., tip portion 5c, or the tip portion of the elastic plate portion 21 on the center side of the rail 3d in the width direction of the rail 3d, i.e., tip portion 5b.

In the rail fastening method of this second embodiment, first, the existing shaft member 4c (see FIG. 7) is removed (step S1 in FIG. 8).

In this step S1, first, as shown in FIG. 9, the shaft member 4c is rotated to rotate the screw portion 4d screwed into the spiral groove 9b, thereby lifting the shaft member 4c. As the shaft member 4c rises and the head portion 4b that has been pressing down the pressing portion 5a rises, the pressing portion 5a, i.e., the tip portion 5c, rises and moves away from the rail bottom portion 3b of the rail 3d. As the shaft member 4c rises further and the head portion 4b rises further, the head portion 4b moves away from the elastic plate portion 22 included in the spring member 5i and also moves away from the washer 4e.

In this step S1, next, as shown in FIG. 10, the shaft member 4c (see FIG. 9) is further rotated to remove the shaft member 4c (see FIG. 9) from the embedding hole 2a, i.e., from the hole portion 9a.

Next, as shown in FIG. 11, the spring member 5i (see FIG. 10) is removed (step S2 in FIG. 8).

Next, as shown in FIG. 12, the shaft member 4 including the shaft portion 4a and the head portion 4b connected to the shaft portion 4a is fixed to the support body 2 on the side of the rail 3 supported by the support body 2 by embedding and fixing the shaft portion 4a in the portion of the support body 2 that is arranged on the side of the rail 3, with the head portion 4b arranged above the shaft portion 4a and above the support body 2 (step S3 in FIG. 8).

In this step S3, the support body 2 is not replaced, so as described above, specifically, the support body 2 can be one in which the embedded plug 9 is embedded in the embedded hole formed on the upper surface of the existing sleeper, such as a PC sleeper. A hole 9a is formed on the upper surface of the embedded plug 9, and a spiral groove 9b is formed on the inner peripheral surface of the hole 9a. Therefore, the support body 2 is one in which a hole 9a is formed on the upper surface of the part of the support body 2 arranged on the side of the rail 3, and a spiral groove 9b, i.e., a female thread is formed on the inner peripheral surface of the hole 9a. In such a case, in step S3, the shaft portion 4a is inserted into the hole portion 9a with the head portion 4b arranged above the shaft portion 4a and the head portion 4b arranged above the support body 2, and the shaft portion 4a inserted into the hole portion 9a is bonded and embedded in the hole portion 9a with adhesive GL1 to fix it to the support body 2, thereby fixing the shaft member 4 to the support body 2 on the side of the rail 3 supported by the support body 2.

As mentioned above, the shaft member 4 may be fixed to the support body 2 by embedding the shaft portion 4a in the support body 2, and the method of fixing the shaft member 4 to the support body 2 does not have to be by adhesive, and is not particularly limited. Therefore, the shaft portion 4a may be a threaded portion 4d (see FIG. 7), i.e., a male thread, but it does not have to be a threaded portion 4d.

In addition, when installing a new rail fastening device, steps S1 and S2 can be omitted and the rail fastening method of this embodiment 2 can start from step S3.

Also, as shown in FIG. 13, a spring member 5 that elastically deforms in the vertical direction is placed between the support body 2 and the head 4b (step S4 in FIG. 8).

In this step S4, as described above, specifically, the spring member 5 may include an elastic plate portion 11, an elastic plate portion 12, and an elastic plate portion 13. The elastic plate portion 11 included in the spring member 5 arranged between the support body 2 and the head portion 4b in step S4 extends in the width direction of the rail 3. The elastic plate portion 12 included in the spring member 5 arranged between the support body 2 and the head portion 4b in step S4 is arranged above the elastic plate portion 11 and extends in the width direction of the rail 3. The elastic plate portion 13 included in the spring member 5 arranged between the support body 2 and the head portion 4b in step S4 connects the end of the elastic plate portion 11 opposite the center side of the rail 3 in the width direction of the rail 3, and the end of the elastic plate portion 12 opposite the center side of the rail 3 in the width direction of the rail 3. In such a case, the pressing portion 5a included in the spring member 5 arranged between the support body 2 and the head portion 4b in step S4 is the tip portion 5c of the elastic plate portion 12 that is closer to the center of the rail 3 in the width direction of the rail 3, or the tip portion 5b of the elastic plate portion 11 that is closer to the center of the rail 3 in the width direction of the rail 3.

As mentioned above, the spring member 5 is not limited to the above example, as long as it is disposed between the support body 2 and the head 4b, and includes a pressing portion 5a that elastically deforms in the vertical direction and presses against the rail bottom portion 3b of the rail 3.

Next, as shown in FIG. 14, a frame member 6 including a frame portion 14 having an upper surface 14a and a lower surface 14b and having a C-shape, U-shape, or U-shape with a portion cut out in the circumferential direction when viewed from above is inserted between the spring member 5 and the head 4b so that the frame portion 14 surrounds the shaft portion 4a when viewed from above (step S5 in FIG. 8).

The shaft member 4 includes a spherical portion 17, and the frame member 6 includes a spherical portion 18 and two tapered portions 19. The spherical portion 17 is formed between the shaft portion 4a and the head portion 4b, and has a spherical shape. The spherical portion 18 is formed on the upper surface 14a of the frame portion 14, and has a spherical shape that can fit with the spherical portion 17. The two tapered portions 19 are respectively connected to two ends EP2 (see FIG. 5(a)), which are both ends of the frame portion 14, and the thickness in the vertical direction of each of the tapered portions 19 decreases with increasing distance from the center of the frame portion 14.

Therefore, as shown in FIG. 2, in step S5, the frame member 6 is inserted between the spring member 5 and the head 4b so that the spherical portion 18 fits into the spherical portion 17, and the rail bottom portion 3b is pressed by the pressing portion 5a, thereby fastening the rail 3 to the support body 2.

In the rail fastening method of the second embodiment, in step S5, a frame member 6 including a frame portion 14 having a C-shape, U-shape, or U-shape in top view is inserted between the spring member 5 and the head portion 4b so that the frame portion 14 surrounds the shaft portion 4a in top view.

In the rail fastening method of the second embodiment, similarly to the rail fastening device of the first embodiment, the head 4b is positioned above the shaft 4a and the head 4b is positioned above the support body 2, and the shaft 4a is embedded and fixed in a portion of the support body 2 that is positioned on the side of the rail 3, thereby fixing the shaft member 4 to the support body 2 on the side of the rail 3 supported by the support body 2. The shaft member 4 includes a spherical portion 17, and the frame member 6 includes a spherical portion 18 that can be fitted with the spherical portion 17 and two tapered portions 19. The frame member 6 is inserted between the spring member 5 and the head 4b so that the spherical portion 18 fits with the spherical portion 17. The frame member 6 is inserted to press down the pressing portion 5a, and the pressed down pressing portion 5a presses the rail bottom portion 3b, thereby fastening the rail 3 to the support body 2.

As a result, like the rail fastening device of embodiment 1, there is no need to replace the existing support body, and no need to embed a dedicated insert in the existing support body, and it is possible to easily change from a screw-tightened rail fastening device to a screwless rail fastening device.

As with the first embodiment, existing stock of supports (rail supports) can be used as is without replacement, reducing maintenance costs. In addition, the lack of screw tightening eliminates the need for fastening status management, such as the inevitable loosening and retightening of bolt and nut fasteners, and reduces the labor required for maintenance work.

As in the first embodiment, the frame member 6 includes two tapered portions 19, so that the frame member 6 has a wedge shape when viewed from the side. This makes it easier to push in the frame member 6 when inserting (installing) the frame member 6 between the spring member 5 and the head 4b of the shaft member 4.

Also, as in embodiment 1, when the shaft member 4 includes a spherical portion 17 and the frame member 6 includes a spherical portion 18, the spherical portion 18 fits into the spherical portion 17 to prevent the relative position of the frame member 6 with respect to the shaft member 4 from shifting when viewed from above, and after the rail 3 is fastened to the support 2, the frame member 6 is prevented from shifting from a predetermined position when viewed from above, and the spring member 5 is prevented from shifting from a predetermined position when viewed from above.

In step S5, specifically, with the two tapered portions 19 sandwiching the shaft portion 4a when viewed from above, the two tapered portions 19 are inserted between the spring member 5 and the head 4b, and the frame member 6 is pushed and moved between the spring member 5 and the head 4b from the state in which the two tapered portions 19 are inserted between the spring member 5 and the head 4b to a state in which the frame portion 14 is inserted between the spring member 5 and the head 4b and the spherical portion 18 is engaged with the spherical portion 17, and with the spherical portion 18 engaged with the spherical portion 17, the rail bottom portion 3b is pressed by the pressing portion 5a, thereby fastening the rail 3 to the support body 2.

Preferably, the spring member 5 includes a through hole 5h that passes through the spring member 5 in the vertical direction, the minimum diameter of the inner diameter DM2 (see FIG. 4(a)) of the through hole 5h is larger than the maximum diameter of the outer diameter DM3 (see FIG. 4(a)) of either the head 4b or the spherical portion 17, and the frame member 6 is engaged with the peripheral portion of the through hole 5h in the spring member 5. Similarly to the through hole 5h, the minimum diameter of the inner diameter of the through hole 5g that passes through the spring member 5 in the vertical direction is also larger than the maximum diameter of the outer diameter DM3 of either the head 4b or the spherical portion 17.

In such a case, as shown in FIG. 12, after the shaft member 4 is fixed to the support body 2 (step S3 in FIG. 8), the spring member 5 can be placed between the support body 2 and the head 4b of the shaft member 4 as shown in FIG. 13 (step S4 in FIG. 8). That is, in step S4, with the head 4b and the spherical portion 17 inserted through the through holes 5h and 5g, the spring member 5 can be lowered until it is placed between the support body 2 and the head 4b. Also, even if the spring member 5 is not pressed and fastened by screwing the shaft portion 4a, it is not necessary to place the spring member 5 before the shaft portion 4a is fixed to the support body 2, so there is no need to press the shaft member 4 against the support body 2 while the shaft portion 4a is bonded and fixed to the support body 2.

In addition, if the minimum diameter of the inner diameter DM2 (see FIG. 4(a)) of the through holes 5h and 5g is greater than the maximum diameter of the outer diameter DM3 (see FIG. 4(a)) of both the head 4b and the spherical portion 17, the spring member 5 can be made detachable even after the rail fastening device of embodiment 1 is installed by the rail fastening method of embodiment 2, and the spring member 5 can be easily replaced even after the rail fastening device of embodiment 1 is installed by the rail fastening method of embodiment 2.

It is preferable that the spring member 5 is different from the spring member 5i. However, for example, when step S4 is performed before step S3, a spring member in which the minimum diameter of the inner diameter DM2 (see FIG. 4(a)) of the through holes 5h and 5g is smaller than the maximum diameter of the outer diameter DM3 (see FIG. 4(a)) of either the head 4b or the spherical portion 17, such as the spring member 5i, can be used instead of the spring member 5.

Preferably, the upper surface 19a and the lower surface 19b (see FIG. 5(b)) of each of the two tapered portions 19 are inclined with respect to the upper surface 14a (see FIG. 5(b)) such that the lower surface 19b is flush with the lower surface 14b (see FIG. 5(b)) and the upper surface 19a is thinner in the vertical direction as it moves away from the center of the frame portion 14.

In this case, the bottom surface of the frame member 6 becomes flat, making it easier to slide the frame member 6 on the spring member 5, i.e., on the elastic plate portion 12 including the plate-shaped portion 5e, and easier to insert, i.e., install, the frame member 6 between the spring member 5 and the head portion 4b of the shaft member 4. This makes it even easier to carry out construction work at the site where the rail 3 is laid.

Preferably, each of the two tapered portions 19 is spaced apart from the spherical portion 18. In this case, even if vibrations are applied to the rail fastening device when the railway vehicle travels on the rail 3, it is possible to reliably prevent or suppress the planar position of the spherical portion 18 engaged with the spherical portion 17 from shifting in the direction from the tapered portion 19 toward the spherical portion 18 (the direction away from the center of the rail 3 in the width direction of the rail 3), causing the spherical portion 17 to come off the spherical portion 18.

In addition, from the viewpoint of easily forming the spherical portion 17 while preventing the planar position of the spherical portion 18 from shifting in the direction from the tapered portion 19 toward the spherical portion 18, when the lower surface 19b (see FIG. 5(b)) of each of the two tapered portions 19 is flush with the lower surface 14b (see FIG. 5(b)), it is preferable that the spherical portion 17 is a convex portion having a downwardly convex spherical shape, and the spherical portion 18 is a concave portion having a downwardly convex spherical shape.

Preferably, the tip of each of the two tapered portions 19 on the side opposite to the frame portion 14 (the side toward the center of the rail 3 in the width direction of the rail 3) has an arc shape centered on the center of the frame portion 14 when viewed from above. In this case, as described above, it becomes easier to insert or install the frame member 6 between the spring member 5 and the head portion 4b of the shaft member 4.

Preferably, the frame portion 14 has a side surface 14c (see FIG. 5(a)) that is arranged on the opposite side of the two tapered portions 19 across the center of the frame portion 14 on the opposite side of the center of the rail 3 in the width direction of the rail 3 when viewed from above, and the side surface 14c is a plane that intersects, preferably perpendicular to, the width direction of the rail 3. In this case, the frame portion 14 has a U-shape with the center side of the rail 3 in the width direction of the rail 3 open when viewed from above.

In such a case, since the side surface 14c is flat, the frame member 6 can be easily inserted between the spring member 5 and the head 4b of the shaft member 4 by hitting the side surface 14c of the frame portion 14 with a hammer or the like.

Preferably, the spherical portion 18 is integrally formed from one end EP2 (see FIG. 5(a)) of both ends to the other end EP2 of both ends. In this case, the frame portion 14 and the spherical portion 18 have a C-shape or U-shape with a portion of the circumferential direction cut out on the center side of the rail 3 in the width direction of the rail 3 when viewed from above.

In such a case, the area of the spherical portion 18 can be increased, so that the planar position of the spherical portion 17 fitted into the spherical portion 18 can be shifted, and the spherical portion 17 can be reliably prevented or suppressed from coming off the spherical portion 18.

Also, consider the case where the elastic plate portion 12 included in the spring member 5 arranged between the support body 2 and the head 4b in step S4 includes a plate-shaped portion 5e having an upper surface that is inclined so that the height position becomes lower as it moves away from the center of the rail 3 in the width direction of the rail 3, and the pressing portion 5a included in the spring member 5 arranged between the support body 2 and the head 4b in step S4 is separated from the rail bottom 3b of the rail 3. Also, in step S5, consider the case where, after step S4, the upper surface of the plate-shaped portion 5e included in the elastic plate portion 12 is inclined so that the height position becomes lower as it moves away from the center of the rail 3 in the width direction of the rail 3, and the pressing portion 5a is separated from the rail bottom 3b of the rail 3, and the frame member 6 inserted between the elastic plate portion 12 and the head 4b presses the pressing portion 5a downward, and the pressing portion 5a pressed downward presses the rail bottom 3b, thereby fastening the rail 3 to the support body 2.

In such a case, preferably, the vertical thickness TH1 (see FIG. 5(b)) of the tip of each of the two tapered portions 19 on the side opposite the frame portion 14 (the side toward the center of the rail 3 in the width direction of the rail 3) is thinner than the vertical distance IN3 (see FIG. 13) between the first portion of the elastic plate portion 12 located directly below the second portion of the spherical portion 17, which is the peripheral portion opposite the center of the rail 3 in the width direction of the rail 3, of the elastic plate portion 12 before the frame member 6 is inserted in step S5.

In this way, since the thickness TH1 is thinner than the interval IN3, the frame member 6 can be more easily inserted (installed) between the spring member 5 and the head 4b of the shaft member 4.

The invention made by the inventor has been specifically described above based on the embodiment thereof, but it goes without saying that the invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention.

A person skilled in the art may conceive of various modifications and alterations within the scope of the concept of this invention, and it is understood that such modifications and alterations also fall within the scope of this invention.

For example, any embodiment described above in which a person skilled in the art has appropriately added or removed components or modified the design, or added or omitted steps or changed conditions, is also included within the scope of the present invention as long as it satisfies the essence of the present invention.

The present invention is effective when applied to a rail fastening device and rail fastening method for fastening a rail to a support body.

Reference Signs List 1, 1a Rail fastening device 2 Support body 2a Embedded hole 3, 3d Rail 3a Rail head 3b Rail bottom 3c Rail web 4, 4c Shaft member 4a Shaft portion 4b Head 4d Threaded portion 4e Washer 5, 5i Spring member 5a Pressing portion 5b, 5c Tip portion 5d, 5e Plate-shaped portion 5f Bent portion 5g, 5h, 5j, 5k Through hole 6 Frame member 7 Track pad 8 Receiver plug 9 Embedded plug 9a Hole portion 9b Spiral groove 9c Spiral iron wire 9d Water drain collar 11-13, 21-23 Elastic plate portion 14 Frame portion 14a, 19a Upper surface 14b, 19b Lower surface 14c Side surface 15 Extension portion 16 Connection portion 17, 18 Spherical portion 19 Tapered portion DM1, DM3 Outer diameter DM2 Inner diameter EP1, EP2 End GL1 Adhesive GP1, GP2 Gap IN1-IN3 Distance TH1 Thickness

Claims (13)

In a rail fastening device for fastening a rail to a support body,
a shaft member including a shaft portion and a head portion, the head portion being disposed above the shaft portion and fixed to the support body on a side of the rail;
a spring member disposed between the support body and the head and elastically deformable in the vertical direction;
A frame member including a frame portion having a first upper surface and a first lower surface and having a C-shape, a U-shape, or a U-shape in a top view, the frame member being inserted between the spring member and the head such that the frame portion surrounds the shaft portion in a top view;
having
the shaft member includes a first spherical portion formed between the shaft portion and the head,
the spring member includes a pressing portion that presses against a bottom portion of the rail,
The frame member is
a second spherical portion formed on the first upper surface of the frame portion and capable of being fitted into the first spherical portion;
two tapered portions connected to both ends of the frame portion, the first thickness of each tapered portion decreasing in the up-down direction as the first thickness increases with increasing distance from the center of the frame portion;
Including,
A rail fastening device in which the frame member is inserted between the spring member and the head so that the second spherical portion engages with the first spherical portion, and the bottom portion is pressed by the pressing portion, thereby fastening the rail to the support body. The rail fastening device according to claim 1,
The spring member includes a through hole that passes through the spring member in a vertical direction,
a minimum inner diameter of the through hole is larger than a maximum outer diameter of both the head portion and the first spherical portion,
A rail fastening device, wherein the frame member is engaged with a peripheral portion of the through hole of the spring member. The rail fastening device according to claim 1 or 2,
a second lower surface of each of the two tapered portions is flush with the first lower surface;
A rail fastening device, wherein the second upper surface of each of the two tapered portions is inclined with respect to the first upper surface so that the first thickness becomes thinner with increasing distance from the center of the frame portion. The rail fastening device according to claim 3,
A rail fastening device, wherein each of the two tapered portions is spaced apart from the second spherical portion. The rail fastening device according to any one of claims 1 to 4,
A rail fastening device, wherein each tip of the two tapered portions has an arc shape centered on the center of the frame portion when viewed from above. The rail fastening device according to any one of claims 1 to 5,
the frame portion has a first side surface disposed on an opposite side to the two tapered portions across a central portion of the frame portion in a top view,
A rail fastening device, wherein the first side is a flat surface. The rail fastening device according to any one of claims 1 to 6,
A rail fastening device, wherein the second spherical portion is integrally formed from a first end of one of the end portions to a second end of the other of the end portions. The rail fastening device according to any one of claims 1 to 7,
A hole is formed in an upper surface of the portion of the support that is disposed to the side of the rail,
A spiral groove is formed on the inner circumferential surface of the hole,
The shaft member is fixed to the support body on the side of the rail by inserting the shaft portion into the hole portion with the head positioned above the shaft portion, and bonding the shaft portion inserted into the hole portion to embed the shaft portion in the hole portion. The rail fastening device according to claim 8,
the shaft portion is a threaded portion that can be screwed into the spiral groove formed on the inner circumferential surface of the hole portion,
The shaft member is fixed to the support body on the side of the rail by having the head positioned above the threaded portion, the threaded portion being threaded into the spiral groove, and the threaded portion threaded into the spiral groove being glued and embedded in the hole portion, thereby forming a rail fastening device. A rail fastening method for fastening a first rail to a support body, comprising the steps of:
(a) fixing a first shaft member including a shaft portion and a first head portion to the support body on a side of the first rail with the first head portion being disposed above the shaft portion;
(b) disposing a first spring member elastically deformable in a vertical direction between the support body and the first head;
(c) inserting a frame member including a frame portion having a first upper surface and a first lower surface and having a C-shape, a U-shape, or a U-shape in a top view between the first spring member and the first head such that the frame portion surrounds the shaft portion in a top view;
having
the first shaft member includes a first spherical portion formed between the shaft portion and the first head portion,
the first spring member includes a first pressing portion that presses a first bottom portion of the first rail,
The frame member is
a second spherical portion formed on the first upper surface of the frame portion and capable of being fitted into the first spherical portion;
two tapered portions connected to both ends of the frame portion, the first thickness of each tapered portion decreasing in the up-down direction as the first thickness increases with increasing distance from the center of the frame portion;
Including,
In step (c), the frame member is inserted between the first spring member and the first head so that the second spherical portion is engaged with the first spherical portion, and the first bottom portion is pressed by the first pressing portion, thereby fastening the first rail to the support body. The rail fastening method according to claim 10,
In the step (c),
The two tapered portions are inserted between the first spring member and the first head portion in a state in which the two tapered portions sandwich the shaft portion when viewed from above,
the frame member is pushed between the first spring member and the first head and moved from a state in which the two tapered portions are inserted between the first spring member and the first head to a state in which the frame portion is inserted between the first spring member and the first head and the second spherical portion is fitted with the first spherical portion;
A rail fastening method, comprising fastening the first rail to the support by pressing the first bottom portion with the first pressing portion while the second spherical portion is engaged with the first spherical portion. The rail fastening method according to claim 10 or 11,
a hole is formed in an upper surface of the support body at a portion disposed to the side of the first rail,
A spiral groove is formed on the inner circumferential surface of the hole,
The rail fastening method further comprises:
(d) a step of removing a second shaft member including a threaded portion and a second head, prior to step (a), in which the second head is disposed above the threaded portion, and a second spring member including a second pressing portion that presses a second bottom portion of a second rail is disposed between the support and the second head, the threaded portion is screwed into the spiral groove, the second head included in the second shaft member screwed into the spiral groove presses the second pressing portion, and the second bottom portion is pressed by the second pressing portion pressed by the second head, thereby fastening the second rail to the support;
(e) removing the second spring member after the step (d) and before the step (a);
having
In step (a), the first head is positioned above the shaft portion, and the shaft portion is inserted into the hole portion, and the shaft portion inserted into the hole portion is glued and embedded into the hole portion, thereby fixing the first shaft member to the support body on the side of the first rail. The rail fastening method according to any one of claims 10 to 12,
The first spring member disposed between the support and the first head in the step (b) is
A first elastic plate portion extending in a width direction of the first rail;
a second elastic plate portion disposed above the first elastic plate portion and extending in a width direction of the first rail;
a third elastic plate portion connecting a side of the first elastic plate portion opposite to a center side of the first rail in a width direction of the first rail and a side of the second elastic plate portion opposite to the center side of the first rail in the width direction of the first rail;
Including,
the first pressing portion included in the first spring member disposed between the support and the first head in the step (b) is a tip end portion of the second elastic plate portion that is located on a center side of the first rail in a width direction of the first rail,
the second elastic plate portion included in the first spring member disposed between the support and the first head in the step (b) includes a plate-shaped portion inclined so that a height position becomes lower with increasing distance from the center of the first rail in the width direction of the first rail,
the first pressing portion included in the first spring member disposed between the support body and the first head portion in the step (b) is spaced from the first bottom portion;
In the step (c), after the step (b), the plate-shaped portion included in the second elastic plate portion is inclined so that its height position decreases as it moves away from the center of the first rail in the width direction of the first rail, and the frame member is inserted between the second elastic plate portion and the first head portion in a state in which the first pressing portion is separated from the first bottom portion, and the frame member inserted between the second elastic plate portion and the first head portion presses the first pressing portion downward, and the first pressing portion pressed downward presses the first bottom portion, thereby fastening the first rail to the support body;
a second thickness in the up-down direction of each of the tip portions of the two tapered portions is thinner than a first distance in the up-down direction between the first portion, which is a first portion of the second elastic plate portion before the frame member is inserted in step (c), and a second portion, which is a peripheral portion of the first spherical portion opposite the center side of the first rail in the width direction of the first rail, and the first portion, which is located immediately below the second portion.

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