JP2016118028A - Rail fastener and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rail fastener in which the work efficiency when laying a rail in a synthetic sleeper is not reduced and the synthetic sleeper is hard to be deteriorated even if vibrations are applied after being laid.SOLUTION: A rail fastener has: a tip part to be inserted to a prepared hole opened into a synthetic sleeper; a straight part continuously arranged in the tip part and having a screw formed in a columnar peripheral surface; a tapered part continuously arranged in the straight part and formed of a screw continued from the straight part on a truncated-cone-shaped peripheral surface; a columnar shaft part continuously arranged in the tapered part; a flange-shaped flange part continuously arranged in the shaft part; and a head part continuously arranged in the flange part and for fixing a rotating tool. A shape of the peak of the screw is formed in the isosceles shape, and a gap between the valley of the screw and the prepared hole is eliminated.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rail fastener for fixing a rail to a synthetic sleeper, a method for manufacturing the rail fastener, and a rail fastening device using the rail fastener.

  In the track, two rails are laid in parallel on a plurality of sleepers, and the sleepers and the rails are fixed by a rail fastening device. In addition to wooden and concrete, there are synthetic sleepers in which urethane resin is reinforced with glass fiber. The rail fastening device supports the rail and is screwed to the synthetic sleeper by a rail fastener such as a screw nail. In the synthetic sleeper, a pilot hole having a diameter larger than that of the screw valley is formed, and a rail fastener is screwed in using an impact wrench or the like. In addition, as shown in Patent Document 1, an invention of a screw nail that does not need to be pulled out even when a member is replaced is disclosed.

JP 2007-303509 A

  However, the screw nail described in Patent Document 1 also conforms to the conventional shape and dimensions. In synthetic sleepers using conventional screw nails, there is an increasing number of cases where the screw nails are pulled out due to the deterioration of the periphery of the screw nails due to the vibration applied each time a train or the like passes. However, by reducing the diameter of the pilot hole in the synthetic sleeper and reducing the gap with the screw nail, deterioration due to vibration can be suppressed, but the torque when screwing the screw nail increases and the work efficiency Will fall.

  Therefore, an object of the present invention is to provide a rail fastener that does not deteriorate the work efficiency when laying rails on a synthetic sleeper and that is less likely to deteriorate even if there is vibration after the laying.

  In order to solve the above-described problems, a rail fastener according to the present invention includes a distal end portion for insertion into a prepared hole in a synthetic sleeper, and a continuous connection with the distal end portion, and a screw on a cylindrical peripheral surface. A formed straight portion; a tapered portion provided continuously with the straight portion, and having a screw formed on a frustoconical circumferential surface thereof; and a cylindrical shaft portion provided continuously with the tapered portion. And a flange-like flange portion provided continuously with the shaft portion, and a head portion provided continuously with the flange portion and fixed to the rotary tool, and the shape of the screw thread is isosceles The gap between the valley of the screw and the pilot hole is eliminated.

  The rail fastener is characterized in that oxide is ground from the surfaces of the straight portion and the tapered portion.

  Further, the rail fastener is characterized in that a lubricant is coated on the surfaces of the straight portion and the tapered portion.

  Further, the rail fastener is characterized in that the tip end portion is tapered.

  Further, the rail fastener is characterized in that the internal angle of the screw is 55 degrees or less.

  Further, the rail fastener is characterized in that the height of the screw is increased within a range that can penetrate the hole formed in the tie plate interposed between the sleeper and the flange portion.

  Moreover, the rail fastener is characterized in that the pitch of the screws is 12 millimeters or more.

  Further, the rail fastener is characterized in that a ridge line of the screw is recessed in a curved shape.

  The rail fastener according to any one of claims 1 to 8, wherein the rail fastener is inclined in a range in which the shape of the screw is isosceles and the outer angle does not become an acute angle. .

  The rail fastening device according to the present invention uses a rail fastener.

  The method for manufacturing a rail fastener according to the present invention includes a tipping step for tapering a tip portion for insertion into a prepared hole in a synthetic sleeper, and a columnar straight connected to the tip portion. A hot-rolling step of forming a screw on the peripheral surface by heating the frustoconical tapered portion connected to the straight portion and the straight portion, and inserting between three rotating cylindrical molds; It has a surface grinding process which grinds an oxide from the surface of the straight part and the taper part, and a surface treatment process which coats the surface of the straight part and the taper part with a lubricant.

  The rail fastener according to the present invention can be screwed with a weaker force than before when laying the rail on the synthetic sleeper, and can improve the working efficiency. Moreover, even if there is vibration or the like when a train or the like passes after laying, since there are few gaps with the synthetic sleepers, deterioration of the synthetic sleepers can be suppressed.

1 is an overall view of a rail fastening device according to the present invention. It is the top view and front view of the fastener for rails which are this invention. It is the figure which compared the screw (b) of the fastener for rails which is this invention, and the screw (a) of the conventional fastener for rails. It is the figure which compared the screwing (b) of the fastener for rails which is this invention, and the screwing (a) of the conventional fastener for rails. It is a flowchart which shows the manufacturing method of the fastener for rails which is this invention. It is a figure explaining the hot rolling in the manufacturing method of the rail fastener which is this invention. It is a flowchart which shows the test method of the fastener for rails which is this invention. It is a figure which shows the result of the comparison test with the conventional of the fastener for rails which is this invention. It is a figure which shows the shape (af) of the thread of the fastener for rails which is this invention. It is a figure which shows the result of the comparison test of the shape of the fastener for rails which is this invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, what has the same function attaches | subjects the same code | symbol, and the repeated description may be abbreviate | omitted.

  First, an overall view of a rail fastening device according to the present invention will be described. FIG. 1 is an overall view of a rail fastening device. The rail fastening device 100 is for fixing the rail 600 to the synthetic sleeper 400. The rail fastening device 100 includes a tie plate 300, a clip 500, and the like.

  The rail 600 is a railroad track. For the rail 600, for example, a metal bar such as steel having a reverse T-shaped cross section is used. A rail 600 having a predetermined length is connected and extended at the end. Two parallel rails 600 are laid linearly or curvedly along the traveling direction of the railway.

  The synthetic sleeper 400 is a sleeper that supports railroad tracks. For the synthetic sleeper 400, for example, a urethane resin plate reinforced with glass fiber is used. The synthetic sleepers 400 are embedded in the ground at predetermined intervals along the traveling direction of the railway. Therefore, the synthetic sleeper 400 is disposed perpendicular to the rail 600.

  The tie plate 300 is a plate material made of wood, metal, or resin that is interposed between the rail 600 and the synthetic sleeper 400. In the tie plate 300, through holes are formed at four corners, and a screw nail 200 is passed through each through hole. The screw nail 200 is a rail fastener according to the present invention, and is screwed into the synthetic sleeper 400 through the tie plate 300.

  The clip 500 is a member such as a wooden member, a metal member, or a resin member that supports the rail 600. Clip 500 is placed on tie plate 300. The clip 500 has holes at both ends, and a clip 510 is passed through both holes. The fastener 510 passes through the clip 500 and is fixed to the tie plate 300 or the synthetic sleeper 400.

  The rail fastening device 100 of the present invention is used for the rail fastening device 100. For this reason, even after the rail 600 is laid, the synthetic sleeper 400 is hardly deteriorated even if it is repeatedly subjected to vibration accompanying the passage of a train or the like or due to other factors, and as a result, the rail fastener is also difficult to come off.

  Next, the structure of the rail fastener which is this invention is demonstrated. FIG. 2 is a plan view and a front view of the rail fastener. The rail fastener is a screw nail 200 for fastening the tie plate 300 to the synthetic sleeper 400 in the rail fastening device 100.

  The screw nail 200 is a metal nail material such as steel in which a screw 270 is formed in a spiral shape. The screw nail 200 includes a head part 210, a flange part 220, a shaft part 230, a taper part 240, a straight part 250, a tip part 260, and the like. The screw nail 200 is integrally formed in the order in which the parts are listed.

  The head 210 is one end side of the screw nail 200. A flange portion 220 is continuously provided below the head portion 210. The head 210 is a portion that can be tightened with a rotating tool such as a wrench, and has a shape that can be easily clamped, such as a rectangular column or a hexagonal column, as shown in the plan view of FIG. The screw nail 200 is screwed into the synthetic sleeper 400 by sandwiching and rotating the head 210 with a wrench or the like.

  The flange portion 220 is a presser in the screw nail 200. A head 210 is connected to the upper side of the flange 220 and a shaft 230 is connected to the lower side. The flange portion 220 is a portion that holds the shaft portion 230 so that it does not come off, and as shown in the plan view of FIG.

  The shaft portion 230 is a portion that penetrates the tie plate 300 of the screw nail 200. A flange portion 220 is continuously provided on the upper side of the shaft portion 230, and a tapered portion 240 is continuously provided on the lower side. The shaft portion 230 has a cylindrical shape so as to pass through a through hole opened in the tie plate 300. A washer 310 may be interposed between the tie plate 300 and the flange portion 220.

  The washer 310 is a plate material made of metal or resin with holes. In order to hold down the tie plate 300, a washer 310 is interposed between the flange portion 220. In order to prevent loosening between the tie plate 300 and the flange portion 220 such as when the screw 200 is pulled out, a lock nut washer or a coil spring may be used.

  The tapered portion 240 is an upper half of a portion of the screw nail 200 that is screwed into the synthetic sleeper 400. A shaft portion 230 is continuously provided on the upper side of the tapered portion 240, and a straight portion 250 is continuously provided on the lower side. The tapered portion 240 has a truncated cone shape for connecting the thin straight portion 250 and the thick shaft portion 230, and a screw 270 protruding in a spiral shape is formed on the peripheral surface.

  The straight portion 250 is the lower half of the portion of the screw nail 200 that is screwed into the synthetic sleeper 400. A tapered portion 240 is continuously provided on the upper side of the straight portion 250, and a tip portion 260 is continuously provided on the lower side. The straight portion 250 has a cylindrical shape, and a screw 270 protruding in a spiral shape is formed on the peripheral surface.

  The screw 270 is a spiral protrusion formed in a portion embedded in the synthetic sleeper 400, that is, in the straight portion 250 and the tapered portion 240 in the screw nail 200. The screw 270 is continuously formed from the lower end of the straight portion 250 to the upper end of the tapered portion 240. The straight portion 250 and the tapered portion 240 are formed so that the height of the protrusion is the same.

  The tip portion 260 is the other end side of the screw nail 200. A straight portion 250 is connected to the upper side of the tip portion 260. The tip portion 260 has a truncated cone shape that tapers downward from the straight portion 250. The distal end portion 260 is the side that is first screwed into the hole vacated in the synthetic sleeper 400, and the distal end portion 260 is thinned so as not to fall when inserted into the hole vacated in the synthetic sleeper 400.

  Further, the screw 270 will be described. FIG. 3 is a diagram comparing the screws of the rail fastener with the screws of the conventional rail fastener. As shown in FIG. 3A, the shape of the screw 270a formed on the conventional straight portion 250a is a right triangle. On the other hand, as shown in FIG.3 (b), the shape of the screw 270 formed in the straight part 250 of this invention is an isosceles triangle shape.

  In the conventional screw 270a shown in FIG. 3A, the height (H) 271a of the screw thread 280a is 3.5 millimeters. The angle of the inner angle (θ1) 272a which is the tip of the thread 280a is 59.7 degrees, the angle of the upper outer angle (θ2) 273a is 90 degrees, and the angle of the lower outer angle (θ3) 274a is 149.7 degrees. . The upper ridge line (L1) 275a of the screw thread 280a is 3.5 millimeters, and the lower ridge line (L2) 276a is 6.9 millimeters, which is 10.4 millimeters in total. The pitch (P) 277a of the thread 280a is 12 millimeters. The cross-sectional area (S1) 281a of the screw thread 280a is 10.5 square millimeters, and the cross-sectional area (S2) 291a of the screw valley 290a is 31.5 square millimeters.

  In the screw 270 of the present invention shown in FIG. 3B, the height (H) 271 of the screw thread 280 is 4.0 millimeters. The angle of the inner angle (θ1) 272 that is the tip of the screw thread 280 is 55 degrees, the angle of the upper outer angle (θ2) 273 is 117.5 degrees, and the angle of the lower outer angle (θ3) 274 is 117.5 degrees. . The upper edge line (L1) 275 of the screw thread 280 is 4.5 millimeters, and the lower edge line (L2) 276 is 4.5 millimeters, for a total of 9.0 millimeters. The pitch (P) 277 of the thread 280 is 12 millimeters. The cross-sectional area (S1) 281 of the screw thread 280 is 8.3 square millimeters, and the cross-sectional area (S2) 291 of the screw valley 290 is 39.7 square millimeters.

  In the screw 270 of the present invention, the height 271 of the screw thread 280 is higher, the area 281 of the screw thread 280 is smaller, and the area 291 of the screw valley 290 is larger than the conventional screw 270. Further, the upper ridge line 275 becomes longer, but the lower ridge line 276 becomes shorter. That is, since the area 291 of the screw valley 290 is large, the amount of the synthetic sleeper 400 sandwiched between the screw threads 280 increases, and the screw 270 is less likely to come off in the present invention.

  When the conventional screw 270a and the screw 270 of the present invention are embedded in the synthetic sleeper 400, they are extracted in the extraction direction (upward direction) 251. The force direction 252a applied to the conventional screw 270a is the same as the drawing direction 251. On the other hand, the force direction 252 applied to the screw 270 according to the present invention is perpendicular to the upper ridge line 275 and is therefore oblique to the drawing direction 251. That is, in the present invention, since the force is distributed in the force direction 252, the screw 270 is hardly pulled out.

  When the upper outer angle 273a is a right angle or an acute angle as in the conventional screw 270a, a large force is applied to the root of the screw 270a when the pulling direction 251 is pulled, and the possibility of fatigue failure increases. Further, as the upper outer angle 273a becomes sharper, the tip of the screw 270a becomes sharper toward the upper side, so that there is a high possibility that the synthetic sleeper 400 will be broken and broken. On the other hand, when the upper outer angle 273 is an obtuse angle like the screw 270 of the present invention, the force applied to the root of the screw 270 when pulled in the pulling direction 251 is small, and the possibility of fatigue failure is low. In addition, since the tip of the screw 270 is not pointed upward or downward, the possibility of damaging the synthetic sleeper 400 is small.

  Next, the screw nail 200 in a state of being screwed into the synthetic sleeper 400 will be described. FIG. 4 is a diagram comparing the screwing of the rail fastener with the screwing of the conventional rail fastener. As shown in FIG. 4 (a), conventionally, there is a large gap between the pilot hole 410a formed in the synthetic sleeper 400 and the screw nail 200a. On the other hand, as shown in FIG. 4B, in the present invention, there is almost no gap between the prepared hole 410 of the synthetic sleeper 400 and the screw nail 200.

  In the case of the conventional screw nail 200a shown in FIG. 4A, first, a prepared hole 410a having an inner diameter (φ1) 411a of 18 mm is formed in the synthetic sleeper 400. Then, a screw nail 200a having an outer diameter (φ2) 292a of 16 millimeters is screwed. Since the height of the screw 270a of the screw nail 200a is 3.5 millimeters, the outer diameter (φ3) 282a of the screw 270a is 23 millimeters. If the screw nail 200a is screwed into the center of the pilot hole 410a, a 1 mm gap exists between the pilot hole 410a and the screw nail 200a. Therefore, a spiral groove is formed on the inner peripheral surface of the pilot hole 410a. Excavated at a depth of 2.5 millimeters.

  In the case of the screw nail 200 of the present invention shown in FIG. 4B, first, a prepared hole 410 is bored in the synthetic sleeper 400 with an inner diameter (φ1) 411 of 16.5 mm. Then, a screw nail 200 having an outer diameter (φ2) 292 of 16 mm is screwed. Since the height of the screw 270 of the screw nail 200 is 4.0 millimeters, the outer diameter (φ3) 282 of the screw 270 is 24 millimeters. Since there is almost no gap between the pilot hole 410 and the screw nail 200, a spiral groove is dug in the inner peripheral surface of the pilot hole 410 to a depth of about 4.0 millimeters.

  In the conventional screw nail 200a, the bite of the screw 270a into the synthetic sleeper 400 is shallow. On the other hand, in the screw nail 200 of the present invention, the screw 270 deeply bites into the synthetic sleeper 400 and is not easily removed. The results of the pulling force test performed on this are shown below. It should be noted that a 140 mm screw nail 200 is used from the tip 260 to the shaft 230, 110 mm from the tip 260 to the taper 240 is screwed into a pilot hole 410 with an inner diameter 411 of about 16 mm in the synthetic sleeper 400. Measure the pulling force when retracted.

  The result when performed on two screw nails 200 is that the first pulling force is 86.5 kilonewtons and the second pulling force is 78.0 kilonewtons. On average, including other data, the pulling force of the present screw nail 200 is about 82.0 kilonewtons. The pulling force of the conventional screw nail 200a is about 69.0 kilonewtons, and the screw nail 200 of the present invention is less likely to come off.

  Further, when the conventional screw nail 200a and the screw nail 200 of the present invention are embedded in the synthetic sleeper 400, it is assumed that repeated vibrations are applied by passing a train or the like. For example, when lateral vibration is applied, the conventional screw nail 200 swings laterally within a gap between the pilot hole 410a, and as a result, the inner peripheral surface of the pilot hole 410a may be degraded. There is sex. In the screw thread 200 of the present invention, there is no gap between the pilot hole 410 and the possibility is low.

  Further, when longitudinal vibration is applied, the screw 270a of the conventional screw nail 200a has a right triangle shape, so that the root of the screw 270a may be damaged by fatigue, and the sharp point of the tip is inside the pilot hole 410a. There is also a possibility that the peripheral surface will be worn out. In the screw nail 200 of the present invention, since the shape of the screw 270 is an isosceles triangle, the force hardly concentrates at the root of the screw 270, and the tip is not sharp on the upper side or the lower side.

  Next, the manufacturing method of the rail fastener which is this invention is demonstrated. FIG. 5 is a flowchart showing a method of manufacturing the rail fastener. The method 700 for manufacturing a rail fastener includes the steps of a leading process 710, hot rolling 720, surface grinding 730, and surface treatment 740. As preparation for manufacturing the screw nail 200 which is a rail fastener, a rod-shaped material 201 is prepared.

  The material 201 includes a head part 210, a flange part 220, a shaft part 230, a taper part 240 without a screw 270, a straight part 250 without a screw 270, and a tip part 260 whose tip is not thinned. For the material 201, a metal such as a general structural rolled steel (SS material) is used. The material 201 is processed by a method such as casting in which a molten metal is poured into a mold and molding, or cutting or grinding that removes an extra portion from a rod-shaped metal.

  In the step 710, the tip portion 260 of the material 201 is processed so as to be tapered. In the material 201, the tip portion 260 has the same diameter as the straight portion 250 without the screw 270, so the tip is thinned by a method such as cutting. When the screw nail 200 is screwed into the prepared hole 410 formed in the synthetic sleeper 400, the thin tip 260 is suspended by being inserted into the prepared hole 410 so that the rotating tool can be easily grasped.

  In the process of hot rolling 720, screws 270 are formed on the taper portion 240 and the straight portion 250 of the material 201 that has been subjected to the leading process 710. Drawing 6 is a figure explaining hot rolling in the manufacturing method of the fastener for rails. The hot rolling 720 uses a rolling machine 721 as shown in FIG. As shown in FIG. 6B, the rolling machine 721 has an upper rolling die 722, a left rolling die 723, and a right rolling die 724, which are arranged adjacent to each other in a triangular shape. The

  As shown in FIG. 6 (b), the material 201 is inserted from the front end portion 260 to the straight portion 250 into the center gap between the upper rolling die 722, the left rolling die 723, and the right rolling die 724. . Each rolling die 722, 723, 724 is a cylindrical die, and as shown in FIG. 6C, unevenness 725 is formed on the side peripheral surface. By heating the material 201 and applying pressure with each of the rolling dies 722, 723, and 724, a spiral screw 270 is formed on the material 201 in accordance with the shape of the unevenness 725, as shown in FIG. 6C. Is done. In addition, the entrance side of each rolling die 722, 723, 724 is slightly wide so that the material 201 can be easily inserted, and thereby a tapered portion 240 is formed.

  In the surface grinding 730 step, unnecessary materials attached to the surface of the material 201 on which the screws 270 are formed are scraped off. The surface of the material 201 is covered with an oxide scale film by heating in the hot rolling 720. The coating of oxide scale is removed from the surface of the material 201 by a method such as shot blasting in which the projection material is collided to grind the surface, and the frictional force when the screw nail 200 is screwed into the synthetic sleeper 400 is reduced.

  In the surface treatment 740 step, the surface of the material 201 on which the screw 270 is formed is covered with a lubricant or the like. Contrary to the surface grinding 730, the surface is coated in order to reduce the frictional force when the screw nail 200 is screwed into the synthetic sleeper 400. For example, the surface slippage is improved by applying a wax. In addition, in order to prevent oxidation of the surface, plating may be performed with a metal thin film that is difficult to oxidize.

  If the screw nail 200 is manufactured by the rail fastener manufacturing method 700 according to the present invention, the tip end portion 260 of the screw nail 200 is thinned by the leading process 710, so that an operator can easily remove the screw nail 200. It can be made to stand upright and can prevent the screw nail 200 from falling down when the screw nail 200 is gripped by a rotating tool.

  Moreover, since the oxidized scale coated on the surface of the screw nail 200 is removed by the surface grinding 730, when the screw nail 200 is screwed into the synthetic sleeper 400, an excessive frictional force is not applied, and work efficiency can be improved. it can. Furthermore, since the surface treatment 740 applies wax to the surface of the screw nail 200, the friction force when the screw nail 200 is screwed into the synthetic sleeper 400 can be reduced, and the working efficiency can be further improved.

  Next, the ease of screwing when the rail fastener according to the present invention is used will be verified. FIG. 7 is a flowchart showing a test method for the rail fastener. FIG. 8 is a diagram showing a result of a comparison test with a conventional fastener for rail. As shown in FIG. 7, the rail fastener test method 800 is performed in the steps of pilot hole excavation 810, hand tightening 820, torque measurement 830, and evaluation 840 in accordance with the actual usage method.

  In the process of drilling a pilot hole 810, a pilot hole 410 is drilled in the synthetic sleeper 400. In the test, a sleeper 400 that is not buried in the ground is placed on a drilling machine, and a cutting tool such as a drill is rotated to make a hole. In the present invention, the inner diameter 411 of the pilot hole 410 is verified at 16 millimeters, and since the inner diameter 411a has been excavated at 18 millimeters in the prior art, it is verified whether the inner diameter 411a is 18 millimeters or 16 millimeters. .

  In the step of hand tightening 820, the distal end portion 260 of the screw nail 200 is inserted into the prepared hole 410 formed in the synthetic sleeper 400. If the distal end portion 260 is not thin, it is difficult for the operator to manually tighten it until it hangs down in the prepared hole 410, and the insertion may fall down shallowly. As in the present invention, the screw nail 200 can easily bite into the pilot hole 410 by making the tip 260 narrow.

  The process of torque measurement 830 verifies the ease of screwing the screw nail 200. In the test, a torque wrench is used to measure the screwing torque. In addition, when screwing in the actual synthetic sleeper 400, an impact wrench or the like is used. The screw nail 200 having the distal end portion 260 inserted into the prepared hole 410 of the synthetic sleeper 400 is screwed until the tapered portion 240 is buried and the shaft portion 230 is protruded.

  The process of evaluation 840 compares the results of torque measurement 830. FIG. 8A verifies the screw nail 200 manufactured by performing the surface treatment 740 without performing the surface grinding 730 as the present invention. Further, FIG. 8B shows a screw nail 200 manufactured by performing surface grinding 730 and surface treatment 740 as the present invention. 8A and 8B, black squares and black circles are the case of the conventional screw nail 200a.

  A black square indicates a screwing torque according to a screwing depth when a screw nail 200a having an inner diameter 411a of 16 mm and an outer diameter 282a of a screw thread 280a of 23 mm is screwed into the pilot hole 410a. At this time, the torque average value when the screwing depth is 110 millimeters is 4100 weight kilograms · centimeter.

  Further, the black circle indicates the screwing torque according to the screwing depth when the screw nail 200a having the inner diameter 411a of 18 mm and the outer diameter 282a of the screw thread 280a of 23 mm is screwed into the pilot hole 410a. Show. At this time, the average torque value when the screwing depth is 110 millimeters is 3000 kilograms-centimeters. By widening the pilot hole 410a, it becomes easy to screw.

  The white circle represents the torque applied according to the screwing depth when the screw nail 200 having an inner diameter 411 of 16 mm and an outer diameter 282 of the screw thread 280 of 24 mm is screwed. Show. As shown in FIG. 8A, the average torque value without surface grinding 730 is 3000 weight kilograms / centimeter. Further, as shown in FIG. 8B, the average torque value with surface grinding 730 is 2500 kg / cm2.

  Even in the case of no surface grinding 730 in FIG. 8A, although the pilot hole 410 is narrowed and the outer diameter 282 of the screw thread 280 is widened, the torque is equal to that in the case of the black circle and the screwing is easy. That does not change. Further, as shown in FIG. 8 (b), in the case of surface grinding 730, the torque is lower than in the case of the black circle at any depth, and it is very easy to twist. Thereby, the work efficiency of the operator who lays a rail etc. with respect to the synthetic sleeper 400 is also improved.

  Next, as a modification of the rail fastener according to the present invention, screw-shaped variations and comparison results thereof will be described. FIG. 9 is a diagram showing the shape of the thread of the rail fastener. FIG. 10 is a diagram showing the results of a comparative test of the shape of the rail fastener. The present invention improves the conventional sawtooth-like right-angled triangular screw 270a and adopts an isosceles triangular screw 270. However, even if the shape is slightly modified, the same effect can be obtained. It is included in the present invention.

  Although the angle of the inner angle 272 of the screw 270 of the screw nail 200 is 55 degrees, as shown in FIG. 9A, the angle of the inner angle 272 of the screw 270 may be further narrowed to 45 degrees, 40 degrees, or 35 degrees. good. By reducing the width of the screw 270, the screwing torque of the screw nail 200 is reduced. However, the durability of the screw 270 may be reduced by reducing the width of the screw 270.

  Here, the screwing torque when the isosceles triangular screw 270 is formed on the screw nail 200 is compared between the case where the inner angle 272 is 45 degrees and the case where the angle is 35 degrees. The inner diameter 411 of the pilot hole 410 opened in the synthetic sleeper 400 is 16 millimeters. For the screw nail 200, the outer diameter 292 is 16 millimeters and the length from the tip 260 to the taper 240 is 115 millimeters. The screw 270 has a pitch 277 of 6 millimeters and a height 271 of 3.5 millimeters, and is formed by cutting instead of hot rolling 720.

  As shown in FIG. 10 (a), when the angle of the inner angle 272 of the screw 270 is 45 degrees, the maximum torque that is a torque average value with a screwing depth of 115 millimeters is 2480 weight kilogram · cm. As shown in FIG. 10B, when the angle of the inner angle 272 of the screw 270 is 35 degrees, the maximum torque that is a torque average value with a screwing depth of 115 millimeters is 1970 weight kilogram · centimeter. .

  10A and 10B, when the angle of the inner angle 272 of the screw 270 is narrowed, the screwing torque is reduced and the screw nail 200 is easily screwed into the synthetic sleeper 400. I understand. In addition, when the angle of the inner angle 272 of the screw 270 is narrowed, the area 291 of the screw valley 290 is increased, so that the screw nail 200 is not easily removed from the synthetic sleeper 200.

  Further, although the height 271 of the screw 270 of the screw nail 200 is set to 4.0 millimeters, as shown in FIG. 9B, the height 271 of the screw 270 may be further increased to 4.5 millimeters. good. However, since the inner diameter of the through hole of the tie plate 300 interposed between the synthetic sleeper 400 is 25 millimeters, it is within a range where the screw nail 200 can be passed.

  Moreover, although the pitch 277 of the screw 270 of the screw nail 200 is 12 millimeters, as shown in FIG. 9C, the pitch 277 of the screw 270 may be further expanded to 13 millimeters. When the pitch 277 of the screw 270 is increased, the area 291 of the screw valley 290 increases, and therefore, the screw nail 200 is difficult to be removed from the synthetic sleeper 200.

  Further, although the upper ridge line 275 and the lower ridge line 276 of the screw 270 of the screw nail 200 are linear, as shown in FIG. 9D, even if the ridge lines 275 and 276 of the screw 270 are recessed in a curved shape. good. When the ridges 275 and 276 of the screw 270 are recessed, the area 291 of the screw valley 290 increases, so that the screw nail 200 is difficult to come off from the synthetic sleeper 200. However, if the inner angle 272 of the screw 270 in FIG. 9A is too narrow, the durability of the screw 270 may be reduced. Conversely, although the area 291 of the screw valley 290 is reduced, the ridge lines 275 and 276 of the screw 270 may be expanded in a curved shape.

  Moreover, although the shape of the screw 270 of the screw nail 200 is an isosceles triangle, it may be inclined upward or downward as shown in FIG. The upper outer angle 273 and the lower outer angle 274 of the screw 270 are both in an obtuse angle range. If one of them becomes a right angle or an acute angle, a strong force is applied to the base of the screw 270 when screwing or pulling out, and the possibility of being broken increases. Also, if one of them is an acute angle, the tip of the screw 270 is sharpened, so that the synthetic sleeper 400 is easily damaged. If both are obtuse angles, the possibility is reduced, and in particular, if the shape is close to an isosceles triangle, the balance of characteristics in screwing and drawing is good.

  In addition, the inner diameter 411 of the pilot hole 410 opened in the synthetic sleeper 400 is narrowed to 16 mm. However, as shown in FIG. The diameter 292 may be as thick as 18 millimeters. By reducing the clearance between the pilot hole 410 and the screw nail 200, the screw nail 200 does not wobble within the pilot hole 410, and the possibility of damaging the synthetic sleeper 400 is reduced.

  Depending on the place where the rail 600 is laid, a modification as shown in FIGS. 9A to 9F or other modifications may be added. Thereby, the effect similar to the fastener for rails of this invention can be acquired. That is, it can be screwed in with a weaker force than before, work efficiency can be improved, and even if there is vibration or the like when a train or the like passes after laying, the gap with the synthetic sleeper 400 is small. The deterioration of the synthetic sleeper 400 can be suppressed.

  As mentioned above, although the Example of this invention was described, it is not limited to these. For example, in the rail fastener manufacturing method 700, the screw 270 of the screw nail 200 is formed by hot rolling 720, but may be formed by cutting the material 201. Further, the surface treatment 740 is performed after the surface grinding 730, but any of the steps may be omitted.

100: Rail fastening device 200, 200a: Screw nail 201: Material 210: Head portion 220: Flange portion 230: Shaft portion 240: Tapered portion 250, 250a: Straight portion 251: Pull-out direction 252, 252a: Force direction 260: Tip Portions 270, 270a: Screws 271, 271a: Height 272, 272a: Inner angles 273, 273a: Outer angles 274, 274a: Outer angles 275, 275a: Ridge lines 276, 276a: Ridge lines 277, 277a: Pitches 280, 280a: Screw threads 281 281a: Area 282, 282a: Outer diameter 290, 290a: Neji valley 291, 291a: Area 292, 292a: Outer diameter 300: Tie plate 310: Washer 400: Synthetic sleeper 410, 410a: Pilot hole 411, 411a: Inner diameter 500: Clip 510: Fastener 00: Rail 700: Manufacturing method 710: Bending 720: Hot rolling 721: Rolling machine 722: Rolling die 723: Rolling die 724: Rolling die 725: Concavity and convexity 730: Surface grinding 740: Surface treatment 800: Test method 810: Drilling a pilot hole 820: Hand tightening 830: Torque measurement 840: Evaluation

Claims (11)

A tip for insertion into a prepared hole in a synthetic sleeper;
A straight portion connected to the tip portion, and having a screw formed on a cylindrical peripheral surface;
A taper portion that is connected to the straight portion, and has a truncated cone-shaped peripheral surface formed with the screw that continues from the straight portion;
A columnar shaft portion provided continuously to the tapered portion;
A bowl-shaped flange portion connected to the shaft portion;
A head portion connected to the flange portion and fixed to the rotary tool;
Form the shape of the screw thread in an isosceles shape,
The gap between the screw valley and the pilot hole is eliminated.
The fastener for rails characterized by the above-mentioned. The oxide was ground from the surface of the straight part and the taper part,
The rail fastener according to claim 1. The surface of the straight part and the taper part is coated with a lubricant,
The rail fastener according to claim 1 or 2, wherein the rail fastener is provided. The tip is tapered,
The rail fastener according to any one of claims 1 to 3, wherein the rail fastener is provided. The internal angle of the screw was 55 degrees or less,
The rail fastener according to any one of claims 1 to 4, wherein the rail fastener is provided. The height of the screw is increased within a range that can penetrate a hole formed in a tie plate interposed between the sleeper and the flange portion.
The rail fastener according to any one of claims 1 to 5, wherein the rail fastener is provided. The screw pitch was 12 mm or more,
The rail fastener according to any one of claims 1 to 6, wherein the rail fastener is provided. The ridgeline of the screw was recessed in a curved shape,
The rail fastener according to any one of claims 1 to 7, wherein the rail fastener is provided. The shape of the screw is inclined in a range where the outer angle does not become an acute angle from an isosceles shape,
The rail fastener according to any one of claims 1 to 8, wherein the fastener is for rails. Using the rail fastener according to any one of claims 1 to 9,
A rail fastening device characterized by that. A tipping process for tapering the tip for insertion into a prepared hole in a synthetic sleeper; and
A cylindrical straight portion connected to the tip and a truncated cone tapered portion connected to the straight portion are heated and inserted between three rotating cylindrical molds. A hot rolling process to form a screw on
A surface grinding step of grinding oxide from the surface of the straight portion and the tapered portion;
A surface treatment step of coating the surface of the straight part and the taper part with a lubricant,
The manufacturing method of the fastener for rails characterized by the above-mentioned.

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