Steel clamping device, steel clamping structure and method for improving straightness of rail end before straightening

Abstract

The present invention discloses a steel clamping device, a steel clamping structure and a method for improving the straightness of the end of a steel rail before straightening, which relates to the metallurgical field and solves the problem that the rail head bends at the end of the steel rail after reverse pre-bending and before straightening. The steel clamping device for improving the straightness of the end of the steel rail before straightening includes a box and a clamp. An installation groove is provided at the top of the box, and the lower part of the clamp is assembled in the installation groove and the upper part is located outside the installation groove. The steel clamping structure for improving the straightness of the end of the steel rail before straightening includes a cooling bed, a steel rail and a steel clamping device. The box is fixedly installed on the side of the static beam. The steel rail is reversely pre-bent and placed on the cooling bed, and the top of the clamp is clamped at the connection between the rail head and the rail web or the connection between the rail web and the rail base of the steel rail. The method for improving the straightness of the end of the steel rail before straightening: after the steel rail is finally rolled and placed on the cooling bed, the pre-bending trolley performs reverse pre-bending on the steel rail; the steel clamping structure clamps the steel rail; the walking beam is lifted, and the steel rail is lifted with the walking beam and separated from the clamp. The present invention is used to improve the straightness of the steel rail before straightening.

Description

Technical Field

[0001] The present invention relates to the field of metallurgical technology, and particularly to a steel clamping device, a steel clamping structure and a method for improving the straightness of the rail end before straightening. Background Art

[0002] After the rail is rolled, it enters the cooling bed for cooling. When it first enters the cooling bed, the whole rail is relatively straight. If no pre-bending is carried out, the rail will bend towards the rail head with more heat capacity after being completely cooled. To reduce the bending degree of the rail before straightening, reverse pre-bending needs to be carried out when the rail first enters the cooling bed after rolling.

[0003] When the rail is reversely pre-bent, under the action of the pre-bending head, the rail is lifted flat, and the center line of the rail web is in a basically horizontal state. After reverse pre-bending, when the rail is placed on the static beam of the cooling bed, the rail is in a natural placement state, and the heavy rail inclines towards the head. Affected by the rolling rhythm and the safety interlock condition that the pre-bending trolley can only receive the next piece of steel after returning to the zero position, the pre-bending trolley cannot maintain for a long time after pre-bending in place. Usually, it can only maintain for 1 - 2 seconds. Due to the short holding time of the pre-bending trolley, the rail will inevitably rebound. At the same time, the existing pre-bending trolley only has a clamping table design that restricts the non-retreat of the rail bottom direction. There is a large traction force generated by the deformation in the rail head direction, and there is no stable device for the pre-bending trolley to resist the traction force in the rail head direction. If the pre-bending trolley stops moving for a period of time after pre-bending in place, affected by the traction force generated by the rail head deformation, the pre-bending trolley will move towards the rail head direction.

[0004] The middle part of the rail is restricted by its own frictional force and the frictional force of the adjacent parts of the rail until the rail cools down and basically maintains its state during pre-bending. However, for the rail end, in addition to its own frictional force, there is no frictional force constraint from the adjacent rail. At the same time, the cooling speed is much faster than that of the middle part. It is difficult for the bending degree of the rail end to be restricted and maintain an ideal pre-bending state, resulting in a large difference between the bending degree of the rail end and the overall bending degree during straightening. Due to the structural limitation of the straightening machine, there is an end straightening blind area during straightening. For the above reasons, the straightness of the rail end is poor, and long-time supplementary straightening is required in the subsequent process, which affects the production rhythm and the quality of the rail end. Summary of the Invention

[0005] The present invention first provides a steel clamping device for being installed on the side of the static beam of the cooling bed, to solve the problem that the rail head bends at the rail end after reverse pre-bending and before straightening, aiming to improve the straightness of the rail before straightening.

[0006] The technical solution adopted by the present invention is: a steel clamping device for improving the straightness of the rail end before straightening, including a box and a clamp. One or more installation grooves are provided at the top of the box. There is at least one clamp and it is columnar. The lower part of the clamp is assembled in the installation groove, and the upper part of the clamp is outside the installation groove.

[0007] Further: Multiple mounting grooves are provided at the top of the box. The sizes of the individual mounting grooves are the same. The individual mounting grooves are arranged at equal intervals and their center lines are parallel to each other.

[0008] Even further: Multiple clamping blocks are arranged at intervals inside the box. Mounting grooves are formed between the clamping blocks. The clamping blocks are fixedly welded or screwed to the box.

[0009] Further: A sliding groove is provided inside the box. Two clamping blocks are placed in the sliding groove. An installation groove is formed between the two clamping blocks. At least two tightening bolts for cooperating with the clamping blocks are respectively arranged at both ends of the sliding groove.

[0010] Specifically: The box is made of steel plate, and the clip is a steel bar and is quadrangular prism-shaped; the outer contour of the box is cuboid-shaped, with a length of 150 mm, a height of 50 mm, and a depth of 100 mm, and the height of the clip is 150 mm.

[0011] The present invention also provides a clip steel structure, which also solves the problem that the rail head is bent at the end of the rail after reverse pre-bending and before straightening. The clip steel structure for improving the straightness of the rail end before straightening includes a cooling bed, a rail, and any one of the above clip steel devices for improving the straightness of the rail end before straightening. The cooling bed includes a static beam and a walking beam. The box is fixedly installed on the side of the static beam. The top surface of the box is flush with or lower than the top surface of the static beam. The height of the top of the clip is less than the maximum lifting height of the walking beam; the rail is reversely pre-bent and placed on the cooling bed, and the top of the clip is clamped at the connection between the rail head and the rail web or at the connection between the rail web and the rail base.

[0012] Specifically: The height of the top of the clip relative to the top surface of the static beam is 10 - 15 mm greater than half of the width of the rail head.

[0013] The beneficial effects of the clip steel device and the clip steel structure for improving the straightness of the rail end before straightening in the present invention are as follows: After the pre-bending trolley reversely pre-bends the rail, the top of the clip is clamped at the connection between the rail head and the rail web, or at the connection between the rail web and the rail base, so as to maintain the reverse pre-bending state of the rail, avoid the rebound phenomenon of the rail after leaving the pre-bending trolley, and thus achieve the purpose of improving the straightness of the front end of the rail before straightening by restricting the deformation trend of the rail to bend towards the rail head on the cooling bed, reduce the wear amount of the straightening coil in the subsequent straightening stage, and at the same time also reduce the upward bending of the front end of the rail after straightening, thereby reducing the time-consuming for supplementary pressing; it can also prevent problems such as leg tips and side abrasions of the rail head caused by excessive end bending of the incoming material.

[0014] After the clip restricts the deformation trend of the rail for a certain period of time, the walking beam is lifted, and the rail is lifted with the walking beam and separated from the clip, and the clip does not affect the production rhythm. Multiple mounting grooves are provided at the top of the box. A clip is placed in different mounting grooves, and rails with different reverse pre-bending degrees can be restricted. The mounting grooves are formed by clamping blocks, with a simple structure, firm fixation, and large bearing capacity.

[0015] The present invention also provides a method for improving the straightness of the rail end before straightening, which solves the problem that the straightness of the rail end is poor after the rail is reverse pre-bent according to the existing method. The technical solution adopted by the present invention to solve this problem is as follows: for the method of improving the straightness of the rail end before straightening, after the rail is finally rolled and transferred to the cooling bed, first, the pre-bending trolley performs reverse pre-bending on the rail; then, the rail is clamped by any of the above clamping steel structures for improving the straightness of the rail end before straightening; finally, the walking beam is lifted, and the rail is lifted with the walking beam and disengaged from the clamp.

[0016] Furthermore: The box is installed on one side of the static beam corresponding to the highest temperature of the rail. At least two clamping steel devices for improving the straightness of the rail end before straightening as described above are provided for each rail, and the clamp is clamped at the connection between the rail head and the rail web.

[0017] Specifically: The time for the clamp to clamp the rail is 15 seconds, the number of clamps is 2 - 4, and the clamps are located at the positions of the first and second steel bars after reverse pre-bending on the clamp cooling bed.

[0018] The beneficial effects of the method for improving the straightness of the rail end before straightening of the present invention are as follows: It strengthens the reverse pre-bending effect of the rail pre-bending curve, improves the straightness of the front end of the rail before straightening, reduces the wear of the straightening ring, and at the same time can also reduce the upward bending of the front end of the rail after straightening, thereby reducing the time-consuming for supplementary pressing. The clamp is clamped at the connection between the rail head and the rail web, requiring a low height of the clamp and more reliable effect. The clamps are located at the positions of the first and second steel bars after reverse pre-bending on the clamp cooling bed. The temperature of the first steel bar is the highest, but the residence time is short; the temperature of the second steel bar is slightly lower, but the residence time is long, fully meeting the requirements of reverse pre-bending and shaping. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the cooperation between the clamping steel device for improving the straightness of the rail end before straightening of the present invention and the rail.

[0020] Reference signs: Box 1, Clamp 2, Screw 3, Rail 4. Detailed Embodiment

[0021] The present invention will be further described below with reference to the drawings.

[0022] Refer to Figure 1 , the first theme of the present invention is a clamping steel device for improving the straightness of the rail end before straightening, including a box 1 and a clamp 2. One or more installation grooves are provided at the top of the box 1. At least one clamp 2 is in a columnar shape, and the lower part of the clamp 2 is assembled in the installation groove, and the upper part of the clamp 2 is located outside the installation groove. The box 1 serves to accommodate and support and fix the lower end of the clamp 2, and the installation groove is preferably vertical.

[0023] When an installation groove is provided at the top of the box 1, there is one clip 2. When multiple installation grooves are provided at the top of the box 1, it is preferable that the sizes of the respective installation grooves are the same, the respective installation grooves are arranged at equal intervals and their center lines are parallel to each other. At this time, the clip 2 can be one or the same as the number of installation grooves. The lower end of the clip 2 can be fixed in the installation groove, or the lower end of the clip 2 is clamped in the installation groove, which is convenient for pulling out the clip from the installation groove and placing it in other installation grooves.

[0024] Installation grooves can be directly provided in the box 1, that is, the installation grooves are provided on the box body. Alternatively, the box 1 includes a front plate and a rear plate, and at least two clamping blocks are arranged at intervals between the front plate and the rear plate, and an installation groove is formed between the clamping blocks. The clamping blocks are fixedly welded or fixed by screws 3 to the front plate and / or the rear plate of the box 1. Or, a sliding groove is provided in the box 1, two clamping blocks are placed in the sliding groove, and the clamping blocks can slide along the sliding groove. An installation groove is formed between the two clamping blocks, and the lower end of the clip 2 is placed in the installation groove. At least two tightening bolts cooperating with the clamping blocks are respectively provided at both ends of the sliding groove. By adjusting the tightening bolts, not only can the clamping blocks clamp the lower end of the clip 2, but also the position of the clip 2 in the sliding groove can be adjusted.

[0025] The box 1 and the clip 2 need to bear a large force. Therefore, it is preferable that both the box 1 and the clip 2 are made of steel, and the clamping blocks are also made of steel. When the frictional force of the end rail cannot control the thermal stress of the rail, a dynamic rebound force that escapes the frictional force control of the cooling bed will appear, and this dynamic rebound force is very large and we do not consider controlling it. What this application mainly controls is the stage when the frictional force can control the thermal stress, and auxiliary control force is increased to prevent the phenomenon that the rail cannot be controlled by the frictional force and dynamic rebound occurs. Therefore, the box 1 and the clip 2 can be made of materials with the same cold strength as the rail 4. For example, the box 1 is made of a steel plate, the clip 2 is a steel bar and is in a quadrangular prism shape, and the clip 2 is made of a steel plate with a thickness of 20 - 40 mm and a width of 50 - 100 mm. The outer contour of the box 1 is in a cuboid shape, with a length of 150 mm, a height of 50 mm, and a depth of 100 mm, and the height of the clip 2 is 150 mm.

[0026] The second theme of the present invention is: a clip steel structure for improving the straightness of the rail end before straightening, see Figure 1, including a cooling bed, a steel rail 4, and the steel clamping device for improving the straightness of the end of the steel rail before straightening. The cooling bed includes a static beam and a walking beam, and the walking beam is the moving beam. The box 1 is fixedly installed on the side of the static beam, and the top surface of the box 1 is flush with or lower than the top surface of the static beam. For example, the top surface of the box 1 is 5 mm lower than the top surface of the static beam. The height of the top of the clip 2 is less than the maximum lifting height of the walking beam, and the walking beam can cross over the clip to complete the forward feeding of the steel rail 4, avoiding the problem that the steel rail 4 cannot be transported forward. For example, the height of the top of the clip 2 relative to the top surface of the static beam is 10 - 15 mm greater than half of the width of the head of the steel rail 4. The steel rail 4 is pre-bent in the reverse direction and placed on the cooling bed, and the top of the clip 2 is clamped at the joint between the head and the web or the joint between the web and the bottom of the steel rail 4. Since the relative height of the joint between the head and the web is lower and the height of the clip 2 required is lower, it is more conducive for the clip 2 to clamp the steel rail 4 at the joint between the head and the web, and the force is more reliable.

[0027] The third subject of the present invention is: a method for improving the straightness of the end of the steel rail before straightening. After the steel rail 4 is finally rolled and put on the cooling bed, first, the pre-bending trolley pre-bends the steel rail 4 in the reverse direction. Then, the steel rail 4 is clamped by any of the above steel clamping structures for improving the straightness of the end of the steel rail before straightening. Among them, the box 1 is installed on one side of the static beam corresponding to the highest temperature of the steel rail 4, and at least two of the above steel clamping devices for improving the straightness of the end of the steel rail before straightening are provided for each steel rail 4, that is, each steel rail 4 is clamped by at least two clips 2. The number of clips 2 is generally 2 - 4, that is, 2 - 4 clips 2 are provided at one end of each steel rail 4. After the number of clips 2 exceeds 4, the improvement effect of increasing the number of clips 2 on improving the straightness of the end of the steel rail before straightening is not obvious. The clip 2 is preferably clamped at the joint between the head and the web of the steel rail 4. Finally, the walking beam is lifted, and the steel rail 4 is lifted with the walking beam and separated from the clip 2.

[0028] The longer the clip 2 clamps the steel rail 4, that is, the longer the fixing time of the clip 2 on the steel rail 4, the better the reverse pre-bending effect. Considering the production rhythm and the fixing effect, the time for the clip 2 to clamp the steel rail 4 can be 15 seconds. In order to reduce the magnitude of the fixing force of the clip 2, the clip 2 is preferably placed at the position corresponding to the highest temperature of the cooling bed and the steel rail 4. Considering the time for the clip 2 to fix the steel rail 4 and the magnitude of the fixing force, combined with the conveying process of the steel rail 4 on the cooling bed, the clip 2 can be placed at the positions of the first steel and the second steel after the reverse pre-bending is completed on the cooling bed, that is, at the positions of the first step and the second step when the steel rail 4 is placed on the cooling bed. The temperature of the first steel is the highest, but the residence time is short; the temperature of the second steel is slightly lower, but the residence time is long, which fully meets the requirements of reverse pre-bending and shaping.

[0029] Taking the 60 kg / m U75V type steel rail as the object, the test is carried out according to the above method for improving the straightness of the steel rail end before straightening. Among them, the thickness of the clip 2 is 20 mm, the width is 60 mm, and the material of the clip 2 is ordinary steel plate. The clip 2 is set at the positions of the first and second steel supports on the cooling bed. The height of the clip 2 above the top surface of the static beam is 30 mm. There are four clips 2, and the spacing is 500 mm. The clip 2 is clamped at the connection of the web and the bottom of the steel rail 4. The clip 2 is 30 mm higher than the top surface of the static beam. Each clip 2 can be adjusted by the tightening bolt to move horizontally left and right by 100 mm. The time for the clip 2 to clamp the steel rail 4 is 15 s. The lifting height of the moving beam is 100 mm.

[0030] The steel rail processed according to the method for improving the straightness of the steel rail end before straightening is straightened by the straightening machine. The straightening reduction of the straightening machine is set normally. The reduction of the 2# horizontal roll is 18.9 mm, the reduction of the 4# horizontal roll is 13.4 mm, the reduction of the 6# horizontal roll is 7.1 mm, and the reduction of the 8# horizontal roll is 0 mm. No abnormality is found in the mechanical system during the straightening stage, and the rolling process does not need to be adjusted.

[0031] After straightening, the camber of the steel rail is measured sectionally according to the railway standard, that is, 1.6 m to 3.1 m is the first section, 2.6 m to 4.1 m is the second section. The standard for the first section is that the upward camber ≤ 0.6 mm and the downward camber ≤ 0.2 mm. The up and down camber of the second section ≤ 0.5 mm. Check the quality of the steel rail after straightening by the straightening machine. It is measured by a 1.5 m straightedge. The straightness of the front end of the steel rail after straightening is shown in Table 1.

[0032] Table 1 Test data of the straightness of the front end of the steel rail after straightening

[0033]

[0034] Comparing the data in Table 1 with the existing industry standards, it can be seen that the specifications such as head deviation and crown of the steel rail after straightening by the straightening machine are all within the control standards. It can be found from the test data that the added steel clamping device can effectively limit the rebound of the steel rail caused by elasticity and internal bending stress. After the rebound of the steel rail is restricted, the straightness of the steel rail end before straightening is effectively improved.

Claims

1. A method for improving the straightness of the end of a rail before straightening, characterized in that: After the rail (4) is finally rolled and sent to the cooling bed, first, the pre-bending trolley performs reverse pre-bending on the rail (4); then, the rail (4) is clamped by the clamping steel structure that improves the straightness of the rail end before straightening; finally, the walking beam is lifted, and the rail (4) is lifted with the walking beam and separated from the clamp (2). Among them, the clamping steel structure that improves the straightness of the rail end before straightening includes a cooling bed, a rail (4), and a clamping steel device that improves the straightness of the rail end before straightening. The cooling bed includes a static beam and a walking beam. The box (1) is fixedly installed on the side of the static beam. The top surface of the box (1) is flush with or lower than the top surface of the static beam. The height of the top of the clamp (2) is less than the maximum lifting height of the walking beam; the rail (4) is reversely pre-bent and placed on the cooling bed. The top of the clamp (2) is clamped at the connection between the rail head and the rail web or the connection between the rail web and the rail bottom of the rail (4); the clamping steel device that improves the straightness of the rail end before straightening includes a box (1) and a clamp (2). One or more installation grooves are provided at the top of the box (1). There is at least one clamp (2) and it is columnar. The lower part of the clamp (2) is assembled in the installation groove, and the upper part of the clamp (2) is located outside the installation groove.

2. The method for improving the straightness of the end of a rail before straightening according to claim 1, characterized in that: A plurality of installation grooves are provided at the top of the box (1), and the sizes of the installation grooves are the same. The installation grooves are arranged at equal intervals and their center lines are parallel to each other.

3. The method for improving the straightness of the end of a rail before straightening according to claim 2, characterized in that: A plurality of clamping blocks are arranged at intervals in the box (1), and installation grooves are formed between the clamping blocks. The clamping blocks are fixedly welded or fixed by screws (3) to the box (1).

4. The method for improving the straightness of the end of a rail before straightening according to claim 1, characterized in that: A chute is provided in the box (1), and two clamping blocks are placed in the chute. An installation groove is formed between the two clamping blocks. At least two tightening bolts that cooperate with the clamping blocks are provided at both ends of the chute.

5. The method for improving the straightness of the end of a rail before straightening according to any one of claims 1 to 4, characterized in that: The box (1) is made of steel plate, and the clamp (2) is a steel bar and is quadrangular prism-shaped; the outer contour of the box (1) is cuboid-shaped, with a length of 150 mm, a height of 50 mm, and a depth of 100 mm. The height of the clamp (2) is 150 mm.

6. The method for improving the straightness of the end of a rail before straightening according to any one of claims 1 to 4, characterized in that: The height of the top of the clamp (2) relative to the top surface of the static beam is 10 - 15 mm greater than half of the head width of the rail (4).

7. The method for improving the straightness of the end of a rail before straightening according to any one of claims 1 to 4, characterized in that: The box (1) is installed on one side of the static beam corresponding to the highest temperature of the rail (4). At least two of the above-mentioned clamping steel devices that improve the straightness of the rail end before straightening are provided for each rail (4). The clamp (2) is clamped at the connection between the rail head and the rail web of the rail (4).

8. The method for improving the straightness of the end of a rail before straightening according to claim 7, characterized in that: The time for the clamp (2) to clamp the rail (4) is 15 seconds. The number of clamps (2) is 2 - 4, and the clamps (2) are located at the positions of the first and second steel bars after reverse pre-bending on the cooling bed of the clamp (2).

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