Automatic prestressing device for sleeper

Abstract

The invention discloses an automatic prestressing device for sleepers, belonging to the technical field of prestressing of sleepers. The device comprises a frame, a longitudinal moving mechanism is arranged on the frame, a first and a second transverse moving mechanism are arranged on the longitudinal moving mechanism, a first tensioning machine head is arranged on the first transverse moving mechanism, and two second tensioning machine heads are arranged on the second transverse moving mechanism. The device is specially designed for tensioning sleepers, has a high degree of mechanization, is helpful to realize automatic tensioning of sleepers, and can realize assembly line operation.

Description

Technical Field

[0001] The invention relates to an automatic prestressing device for a sleeper, belonging to the technical field of prestressing of sleepers. Background Art

[0002] With the increasing development of railway system transportation, the application of prestressed concrete sleepers has increased dramatically. The sleeper is an important load-bearing component of the track system under the action of train loads. It bears various forces from the rails and elastically transmits the forces to the roadbed, which can effectively maintain the track gauge, direction and position. At present, most of the sleepers laid in my country are concrete sleepers. In the sleeper production process, the prestressing of the sleeper is an important factor affecting the processing quality of the sleeper. The spiral rib steel wire of the prestressed concrete sleeper is affected by various factors during the prestressing process, and there is a non-uniform tensioning phenomenon. The uneven stress distribution caused by this may have an adverse effect on the bearing capacity and service life of the sleeper.

[0003] At present, most of the prestressing equipment of concrete sleeper manufacturers cannot realize automatic tensioning and recording. Instead, they control the tensioning elongation of the prestressed tendons through manual measurement, and use the oil pump pressure gauge to read and control the tensioning force. Inaccurate control of the stress of the sleeper tendons and the prestressing elongation is the main reason for the cracks in the prestressed structure, which leads to excessive deformation of the prestressed structure and even structural failure or scrapping. In addition, the existing tensioning equipment is cumbersome to operate when used for sleeper tensioning, and is inconvenient to use. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention proposes an automatic prestressing device for sleepers, which is specially designed for sleeper tensioning, has a high degree of mechanization, helps to realize automatic tensioning of sleepers, can realize automatic synchronous tensioning, improves non-uniform tensioning and the uneven stress distribution caused by it, improves the processing quality of sleepers, and can realize assembly line operation.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A sleeper prestressed automatic tensioning device comprises a frame, a longitudinal moving mechanism is arranged on the frame, a first and a second transverse moving mechanism are arranged on the longitudinal moving mechanism, a first tensioning machine head is arranged on the first transverse moving mechanism, and two second tensioning machine heads are arranged on the second transverse moving mechanism;

[0007] The tensioning machine head includes a shell for transmitting pressure, a top arm is provided at the front end of the shell, two parallel through-type jacks are provided at the rear end of the shell, each through-type jack is provided with a force sensor and a displacement sensor, a main pull rod is passed through each through-type jack, and two nut screwing mechanisms driven by a motor are also provided at the front of the shell, the screwing heads of the nut screwing mechanisms are exposed at the front end of the shell, and there is a straight through path from the screwing head to the rear end of the nut screwing mechanism, and each straight path is directly opposite to the end of a main pull rod, and the end of the main pull rod has an expanded structure; there is also a pull rod connection mechanism between the nut screwing mechanism and the main pull rod, and the pull rod connection mechanism includes a shell and a connection The connecting body is provided with two first notches and two second notches, the two first notches are respectively used to insert the rod body of the corresponding main pull rod and hang the expanded structure of the rod body end, the two second notches are respectively used to insert the rod body of the corresponding steel bar tensioning rod and hang the expanded structure of the rod body end, and the outer shell has shell notches corresponding to the positions of the notches on the connecting body; a reset spring arranged along the tensioning direction is provided between the connecting body and the outer shell, and when the connecting body is in the reset state, the first notch is located at the rear end of the expanded structure of the corresponding main pull rod end, and the pull rod connecting mechanism is connected with a displacement mechanism whose movement direction is perpendicular to the main pull rod, and when the displacement mechanism is reset, each pull rod is disengaged from the corresponding notch;

[0008] The two second tensioning machine heads are arranged in parallel, and the directions of the screwing heads of the two second tensioning machine heads are opposite to the direction of the screwing head of the first tensioning machine head.

[0009] Furthermore, the force sensor is a column force sensor, which is arranged at the rear end of the through-type jack; the front end of the through-type jack is against the outer wall of the shell; the main pull rod passes through the column force sensor and the through-type jack in sequence and enters the interior of the shell.

[0010] Furthermore, a flange is connected to the end of the main pull rod, a screw hole is provided at the center of the flange, the flange is threadedly connected to the main pull rod, and the flange is fixedly connected to the end of the force sensor by screws.

[0011] Furthermore, the nut tightening mechanism includes a gear transmission mechanism, and the gear transmission mechanisms of the two nut tightening mechanisms in the same tensioning machine head are driven by the same motor. The tightening head is a screw sleeve arranged at the front end of the hollow shaft rod for tightening the nut, and the hollow shaft rod is inserted in the center of the final gear of the gear transmission mechanism by a key connection.

[0012] Furthermore, the hollow shaft has the telescopic freedom relative to the gear transmission mechanism, and a compression spring is sleeved on the hollow shaft for pushing it forward.

[0013] Furthermore, the two second tensioning machine heads are arranged in the same frame, and each second tensioning machine head is connected to an adjustment mechanism that enables it to move up and down in the frame.

[0014] Furthermore, the adjustment mechanism is a push rod mechanism, the second tensioning machine heads are constrained on the guide rails in the frame, and the guide rails are also provided with a limiting structure for limiting the highest position and the lowest position of each second tensioning machine head.

[0015] Furthermore, the spacing between the screwing heads in the two second tensioning machine heads is inconsistent.

[0016] Furthermore, the longitudinal moving mechanism and the transverse moving mechanism are both push rod mechanisms, and both the longitudinal moving mechanism and the transverse moving mechanism are provided with limiting structures.

[0017] Furthermore, the displacement mechanism is a push rod mechanism.

[0018] It can be seen from the above description that the beneficial effects of the technical solution of the present invention are:

[0019] 1. The present invention can tension the sleeper at both ends, wherein two steel bars of the sleeper are tensioned at one end and the other four steel bars of the sleeper are tensioned at the other end, thereby realizing the mechanization and automation of the tensioning of the sleeper.

[0020] 2. Each tensioning machine head of the present invention is integrated with a force sensor and a displacement sensor, which can directly read the prestress value and the tensioning elongation value during the tensioning process, providing accurate reference data for prestressing, thereby ensuring the tensioning quality.

[0021] 3. In each tensioning machine head of the present invention, the tensioning force can be transmitted through the pull rod connection mechanism, and the nut can be automatically locked through the nut screwing mechanism. This method has a high degree of automation and helps to improve the quality and efficiency of the operation.

[0022] 4. After the present invention completes one tensioning operation, it can be quickly withdrawn, and the corresponding mechanism automatically returns to its original position under the action of the spring, so that continuous operation in an assembly line style can be realized, further improving the operation efficiency.

[0023] 5. The present invention can realize automatic synchronous tensioning through feedback adjustment of force sensors and displacement sensors, improve non-uniform tensioning and the uneven stress distribution caused by it, and improve the processing quality of sleepers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly describe this patent, one or more drawings are provided below.

[0025] Figure 1 Schematic diagram of the overall structure of the tensioning device in the embodiment.

[0026] Figure 2 for Figure 1 Schematic diagram of the tensioning machine head on the middle left.

[0027] Figure 3 for Figure 2Schematic diagram of the internal structure.

[0028] Figure 4 for Figure 2 Side cross-sectional view of .

[0029] Figure 5 for Figure 4 Schematic diagram of the structure of the nut screwing mechanism.

[0030] Figure 6 for Figure 4 Schematic diagram of the structure of the connecting body of the middle pull rod connecting mechanism.

[0031] Figure 7 for Figure 1 Schematic diagram of the tensioning machine head at the middle right end.

[0032] Figure 8 for Figure 7 Side cross-sectional view of .

[0033] Fig. 9 for Figure 7 Right view of .

[0034] Fig.10 Schematic diagram of the sleeper prestressing mold.

[0035] Fig.11 for Fig.10 Side view of. DETAILED DESCRIPTION

[0036] In order to facilitate technical personnel in this field to understand the technical solution of this patent, the technical solution of this patent is further explained in the form of specific cases below.

[0037] like Figure 1 As shown, a sleeper prestressing automatic tensioning device includes a frame 01, a longitudinal moving mechanism 02 is provided on the frame 01, the longitudinal moving mechanism drives a crossbeam to move up and down, the crossbeam is provided with a guide rail and two transverse moving mechanisms 03, the two transverse moving mechanisms respectively drive the first tensioning machine head at the left end and the two second tensioning machine heads at the right end to move transversely on the guide rail. Both the longitudinal moving mechanism and the transverse moving mechanism can adopt a push rod mechanism, and both the longitudinal moving mechanism and the transverse moving mechanism can be provided with a limit structure.

[0038] like Figures 2 to 6As shown, the left end machine head includes a shell 1 for transmitting pressure, a top arm 11 is provided at the front end of the shell 1, and two parallel through-type jacks 31 are provided at the rear end of the shell 1. Each through-type jack 31 is provided with a force sensor 32 and a displacement sensor 33, and a main pull rod 4 is passed through each through-type jack 31. Two nut screwing mechanisms driven by a motor 21 are also provided at the front of the shell 1. The screwing head 24 of the nut screwing mechanism is exposed at the front end of the shell 1. There is a straight through path from the screwing head 24 to the rear end of the nut screwing mechanism, and each straight path is directly opposite to the end of a main pull rod 4. The end of the main pull rod 4 has an expanded structure 40; there is also a pull rod connection mechanism between the nut screwing mechanism and the main pull rod, and the pull rod connection mechanism includes a shell 51 and a connector 52, and the connector 52 is provided with two first notches and two second slots 520, the two first slots are respectively used to insert the rod body of the corresponding main pull rod 4 and hang the expanded structure 40 at the end of the rod body, the two second slots 520 are respectively used to insert the rod body of the corresponding steel bar tensioning rod and hang the expanded structure at the end of the rod body, the outer shell 51 has an outer shell slot 510 corresponding to the slot position on the connecting body; a guide rail 54 and a reset spring 53 arranged along the tensioning direction are provided between the connecting body 52 and the outer shell 51, when the connecting body is in the reset state, the first slot is just located at the rear end of the expanded structure at the end of the corresponding main pull rod, the outer shell 51 of the pull rod connecting mechanism is connected with a displacement mechanism 55 whose movement direction is perpendicular to the main pull rod 4, and is constrained in the shell 1 by the guide rail 511; the displacement mechanism can adopt a push rod mechanism, and when the displacement mechanism is reset, each pull rod disengages from the corresponding slot.

[0039] Furthermore, the force sensor 32 is a columnar force sensor, which is arranged at the rear end of the through-type jack 31; the front end of the through-type jack 31 is against the outer wall of the shell 1; the main pull rod 4 passes through the columnar force sensor 32 and the through-type jack 31 in sequence, and enters the interior of the shell 1.

[0040] Furthermore, a flange 34 is connected to the end of the main pull rod 4, a screw hole is provided at the center of the flange 34, the flange 34 is threadedly connected to the main pull rod 4, and the flange 34 is fixedly connected to the end of the force sensor 32 by screws.

[0041] Furthermore, the nut screwing mechanism includes a gear transmission mechanism 22, and the screwing head 24 is a screw sleeve arranged at the front end of a hollow shaft 23 for screwing the nut. The hollow shaft 23 is inserted into the center of the final gear of the gear transmission mechanism 22 by a key connection.

[0042] In addition, the hollow shaft 23 has a degree of telescopic freedom relative to the gear transmission mechanism 22, and a compression spring 25 is sleeved on the hollow shaft 23 for pushing it forward. Obviously, the hollow shaft 23 should have a limit structure to prevent it from escaping from the gear transmission mechanism 22. In order to ensure that the screwing head screws the nut to the bottom as much as possible, the extension length of the screwing head should be calculated in advance, and the compression spring 25 should always be kept in a compressed state to provide sufficient thrust.

[0043] like Figures 7-8 As shown, the right end is a mirror-image arrangement of two heads, each of which has the same structure as the left head, and will not be described here. The two heads are arranged in the same outer frame 7, and move up and down on the corresponding guide rails through adjustment mechanisms 71 and 72 respectively. A limit structure can also be set on the guide rail to limit the highest and lowest positions of each head. The spacing between the heads can be adjusted by the adjustment mechanism to adapt to the distribution of tie rods of different specifications of tensioning molds.

[0044] like Fig. 9 As shown, the spacing between the screwing heads in the upper and lower heads is inconsistent, which is also to adapt to the distribution of the tie rods of the corresponding tensioning mold.

[0045] Fig.10 , 11 The tensioning die adapted to the present device comprises a die body 6, in which a rectangular groove is provided; six tie rods are respectively passed through the side walls of the die body at both ends of the groove, wherein two short tie rods 62 located on the same horizontal plane and four long tie rods 61 located at the four corners of the outer periphery of the two short tie rods are provided on one side wall, and four short tie rods directly opposite to the four long tie rods and two long tie rods directly opposite to the two short tie rods are provided on the other side wall, and the two directly opposite tie rods are used to pull the threaded steel bars 63 connected therebetween. Among them, the inner end of the long tie rod is a threaded cavity for connecting the threaded steel bars, and the rod body after the threaded cavity is sequentially a first light rod section for passing through the die end wall, an external threaded section for connecting the tensioning locking nut, and a second light rod section; the end of the second light rod section has a tail end for screwing, and a bulging structure is provided at the front of the tail end. The inner end of the short pull rod is a threaded cavity for connecting threaded steel bars, behind the threaded cavity is a smooth rod section for passing through the end wall of the mold, the end of the smooth rod section is a stopper for supporting the outer wall of the mold, and a tail end for screwing is provided behind the stopper.

[0046] During tensioning, the tensioning mold is transported to the automatic tensioning device by a trolley, the longitudinal moving mechanism of the device descends, and then the lateral moving mechanisms at both ends drive the machine head at this end to approach the mold, and the long pull rod of the mold just penetrates the screwing head of the corresponding nut screwing mechanism until the top arm at the front end of the machine head shell is against the side wall of the mold, and the screwing head is just sleeved on the locking nut. Then, the displacement mechanism lowers the pull rod connection mechanism, so that the expanded structure of the main pull rod and the long pull rod is placed in the corresponding notch, and tensioning can begin. During the tensioning process, the displacement sensor and force sensor on the machine head can synchronously read the relevant data and provide feedback, thereby improving the tensioning accuracy and ensuring the tensioning quality. After the tensioning is completed, the screwing head of the nut screwing mechanism rotates to tighten the locking nut, and then the displacement mechanism, lateral moving mechanism and longitudinal moving mechanism return to their positions, waiting for the next tensioning.

[0047] The entire tensioning process can be automated through program control. The tensioning quality can be guaranteed based on the feedback data from the displacement sensor and force sensor. In addition, the mold can be transferred through a trolley to achieve assembly line operation, thereby greatly improving the operating efficiency.

[0048] It should be pointed out that the above specific implementation methods are only specific examples of the implementation scheme of this patent. They do not and cannot cover all the implementation methods of this patent. Therefore, they cannot be regarded as limiting the scope of protection of this patent; all implementation schemes with the same concept as the above cases, or combination schemes of the above schemes, are within the scope of protection of this patent.

Claims

1. A sleeper prestressing automatic tensioning device, characterized in that: The machine comprises a frame, a longitudinal moving mechanism is provided on the frame, a first and a second transverse moving mechanism are provided on the longitudinal moving mechanism, a first tensioning machine head is provided on the first transverse moving mechanism, and two second tensioning machine heads are provided on the second transverse moving mechanism; both the longitudinal moving mechanism and the transverse moving mechanism are push rod mechanisms, and both the longitudinal moving mechanism and the transverse moving mechanism are provided with a limit structure; The tensioning machine head includes a shell for transmitting pressure, a top arm is provided at the front end of the shell, two parallel through-type jacks are provided at the rear end of the shell, each through-type jack is provided with a force sensor and a displacement sensor, a main pull rod is passed through each through-type jack, and two nut screwing mechanisms driven by a motor are also provided at the front of the shell, the screwing heads of the nut screwing mechanisms are exposed at the front end of the shell, and there is a straight through path from the screwing head to the rear end of the nut screwing mechanism, and each straight path is directly opposite to the end of a main pull rod, and the end of the main pull rod has an expanded structure; there is also a pull rod connection mechanism between the nut screwing mechanism and the main pull rod, and the pull rod connection mechanism includes a shell and a connection The connecting body is provided with two first notches and two second notches, the two first notches are respectively used to insert the rod body of the corresponding main pull rod and hang the expanded structure of the rod body end, the two second notches are respectively used to insert the rod body of the corresponding steel bar tensioning rod and hang the expanded structure of the rod body end, and the outer shell has shell notches corresponding to the positions of the notches on the connecting body; a reset spring arranged along the tensioning direction is provided between the connecting body and the outer shell, and when the connecting body is in the reset state, the first notch is located at the rear end of the expanded structure of the corresponding main pull rod end, and the pull rod connecting mechanism is connected with a displacement mechanism whose movement direction is perpendicular to the main pull rod, and when the displacement mechanism is reset, each pull rod is disengaged from the corresponding notch; The nut screwing mechanism includes a gear transmission mechanism. The gear transmission mechanisms of the two nut screwing mechanisms in the same tensioning machine head are driven by the same motor. The screwing head is a screw sleeve provided at the front end of a hollow shaft for screwing the nut. The hollow shaft is inserted in the center of the final gear of the gear transmission mechanism by a key connection. The hollow shaft has a telescopic freedom relative to the gear transmission mechanism, and a compression spring is sleeved on the hollow shaft for pushing it forward; The two second tensioning machine heads are arranged in parallel, and the directions of the screwing heads of the two second tensioning machine heads are opposite to the direction of the screwing head of the first tensioning machine head; the two second tensioning machine heads are arranged in the same frame, and each second tensioning machine head is connected to an adjustment mechanism for enabling it to move up and down in the frame; the spacing between the screwing heads in the two second tensioning machine heads is inconsistent.

2. The sleeper prestressing automatic tensioning device according to claim 1, characterized in that: The force sensor is a column force sensor, which is arranged at the rear end of the through-type jack; the front end of the through-type jack abuts against the outer wall of the shell; the main pull rod passes through the column force sensor and the through-type jack in sequence and enters the interior of the shell.

3. The sleeper prestressing automatic tensioning device according to claim 1, characterized in that: The end of the main pull rod is connected with a flange, the center of the flange has a screw hole, the flange is threadedly connected to the main pull rod, and the flange is fixedly connected to the end of the force sensor by screws.

4. The sleeper prestressing automatic tensioning device according to claim 1, characterized in that: The adjusting mechanism is a push rod mechanism, and the second tensioning machine head is constrained on the guide rail in the frame. The guide rail is also provided with a limiting structure for limiting the highest position and the lowest position of each second tensioning machine head.

5. The sleeper prestressing automatic tensioning device according to claim 1, characterized in that: The displacement mechanism is a push rod mechanism.

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