Jack positioning auxiliary device and positioning method

Abstract

The application relates to a jack positioning auxiliary device and a positioning method, which comprise: steel guide rails, which are fixed on the top of cast-in-place box girders through the combination of embedded bolts and nuts; sliding mechanisms, which are slidably arranged between two groups of the steel guide rails and are adapted to slide left and right along the two groups of the steel guide rails; and lifting mechanisms, which are vertically slidably arranged on the sliding mechanisms and are adapted to slide forward and backward along the sliding mechanisms. The steel guide rails are arranged on the cast-in-place box girders, and the sliding mechanisms are installed afterwards, so that the jack can be used to adjust the transverse position of the cast-in-place box girder tension section without occupying the space of the operation frame, the working personnel can avoid crossing the jack support or trolley during construction, the safety of the personnel is ensured, and the problem that the operation space of the cast-in-place box girder tension end is small is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of construction engineering, in particular to a jack positioning auxiliary device and positioning method. BACKGROUND

[0002] The cast-in-place box girder basically uses prestressed structure, and in the process, the steel strand needs to be tensioned by a jack. At present, the traditional prestressed tensioning construction method of full-support box girder is to set several rows of supports longitudinally as a tensioning operation platform when the box girder support is erected, to set up a steel pipe to suspend a jack support, and to suspend the support jack on the support operation platform by a hoist and adjust the position of the jack by the hoist to meet the construction requirements.

[0003] For the traditional construction method, the operation space at the tensioning end of the box girder is small, personnel are working in the high and open space, the tensioning construction is difficult and dangerous, and for tensioning of prestressed steel strands at different positions, the position of the jack needs to be adjusted manually, and there is a problem that the anchor pad is damaged due to the non-parallelism between the jack and the axis of the steel strand, and the subsequent treatment is extremely cumbersome and has great safety hazards. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the problems in the prior art, such as small operation space at the tensioning end of the cast-in-place box girder, difficult prestressed tensioning construction in the open space, and to provide a jack positioning auxiliary device and positioning method.

[0005] The technical solution adopted by the present application to solve the technical problem is: a jack positioning auxiliary device and positioning method, comprising:

[0006] Steel guide rails, which are fixed on the top of the cast-in-place box girder by a combination of pre-buried bolts and nuts;

[0007] A sliding mechanism, which is slidingly arranged between the two groups of steel guide rails, is adapted to slide left and right along the two groups of steel guide rails;

[0008] A lifting mechanism, which is vertically slidingly arranged on the sliding mechanism, is adapted to slide forward and backward along the sliding mechanism;

[0009] A rotating mechanism, which is rotationally arranged at the bottom of the lifting mechanism, is used to mount a jack and is adapted to adjust the angle of the jack.

[0010] Further, the sliding mechanism comprises a trolley between the two steel guide rails, a plurality of rotating shafts rotationally arranged on both sides of the trolley in a mirror image, and a plurality of wheels arranged on the rotating shafts;

[0011] The plurality of wheels are arranged in two rows on the two steel guide rails;

[0012] The inner cavity of the steel guide rail is arranged in a transverse convex shape.

[0013] Further, the sliding mechanism further comprises a through slot arranged transversely on the plate cart, a first rectangular slot arranged on one side of the through slot, a lifting block arranged in the first rectangular slot, an L-shaped slot arranged on one side of the through slot, a first supporting slot arranged on the lifting block, a first supporting block slidingly arranged in the L-shaped slot, a second supporting block slidingly arranged in the first supporting slot, and a connecting rod arranged between the first supporting block and the second supporting block.

[0014] A rotating hole for connecting one of the rotating shafts is arranged on the first rectangular slot.

[0015] The connecting rod is slid, and the first supporting block and the second supporting block can be transversely slid along the L-shaped slot and the first supporting slot respectively, so that the first supporting block can be vertically slid along the L-shaped slot to drive the lifting block to descend.

[0016] Further, the lower end of the lifting block is arranged with an isosceles trapezoidal slot with a narrow upper end and a wide lower end.

[0017] The isosceles trapezoidal slot is collinear with the vertical midline of the rotating hole.

[0018] The lifting block can drive the isosceles trapezoidal slot to descend to the rotating shaft.

[0019] Further, the sliding mechanism further comprises a longitudinal steel beam arranged on the plate cart, a steel stand column arranged on the longitudinal steel beam, a steel guide beam arranged at the top end of the steel stand column, an inclined steel beam arranged between the steel guide beam and the plate cart, an inclined slot arranged on the inclined steel beam, and a movable hole arranged on the steel guide beam.

[0020] The walls of the inclined slot can respectively fit the two sides of the longitudinal steel beam and the two sides of the steel stand column.

[0021] The lifting mechanism is slidingly connected to the movable hole.

[0022] Further, the lifting mechanism comprises a steel lifting cylinder arranged through the movable hole, a vertical rod arranged inside the steel lifting cylinder, a fixed block arranged at the top end of the steel lifting cylinder, and a supporting pad arranged at the bottom end of the steel lifting cylinder.

[0023] The fixed block can descend to the steel guide beam.

[0024] The steel lifting cylinder can move forward and backward in the movable hole.

[0025] The vertical rod can drive the supporting block to ascend and descend along the steel lifting cylinder.

[0026] Further, the lifting mechanism further comprises a strip hole arranged on the steel hanging cylinder, and a first hand screw bolt penetrating through the strip hole and screwing the vertical rod;

[0027] The handle of the first hand screw bolt is larger than the width of the strip hole;

[0028] The first hand screw bolt can screw against the strip hole.

[0029] Further, the rotating mechanism comprises a rotating hole arranged on one side of the supporting block, a shaft sleeve arranged in the rotating hole, a rotating shaft rotatably arranged in the shaft sleeve, a base arranged on the other side of the rotating shaft, and a fixing ring arranged on the upper end of the base;

[0030] The jack is arranged on the base through a fixing bolt, and the jack is arranged in the fixing ring.

[0031] The jack can be adjusted in angle with the base.

[0032] Further, the rotating mechanism further comprises a threaded hole penetrating between the supporting block and the rotating hole, a second through hole arranged on the shaft sleeve, and a second hand screw bolt penetrating through the threaded hole and the second through hole;

[0033] The second hand screw bolt can abut against the rotating shaft.

[0034] Further, the method for use is as follows:

[0035] S1, during the construction of the cast-in-place box girder, the pre-buried bolt is measured and buried, and after the cast-in-place box girder is poured and reaches the strength that meets the tensioning condition, two groups of steel rails are connected on the top of the cast-in-place box girder through the combination of the pre-buried bolt and the nut;

[0036] S2, the sliding mechanism is installed on the two groups of steel rails, the lifting mechanism is connected with the rotating mechanism and the sliding mechanism after being stretched, and the jack is installed on the rotating mechanism;

[0037] S3, the sliding mechanism is slid on the two groups of steel rails by moving the jack, the transverse position of the jack on the tensioning section of the cast-in-place box girder is adjusted, during the moving process, the lifting mechanism needs to be moved to the outermost side of the sliding mechanism in advance to ensure that the entire jack adjusting device will not collide with the steel beam to be tensioned, and after the transverse position of the jack is aligned, the position of the sliding mechanism is fixed;

[0038] S4, the height of the rotating mechanism is adjusted and locked by adjusting the lifting mechanism, so that the jack is at the same height as the steel strand, the longitudinal position of the jack is adjusted by moving the lifting mechanism, the angle of the jack is adjusted by the rotating mechanism and locking, and the jack is fixed on the anchor pad, and then tensioning is performed;

[0039] S5, if other steel strands need to be continued to be tensioned, repeat S3-S4 steps to construct.

[0040] The beneficial effect of the present application is that the steel guide rail is arranged on the cast-in-place box girder, the sliding mechanism is installed later, the jack can adjust the transverse position of the tensioning section of the cast-in-place box girder without occupying the space of the operation frame in the free space, the construction personnel can avoid crossing the jack support or trolley during construction, the safety of the personnel is ensured, and the problem of small operation space of the tensioning end of the cast-in-place box girder is solved.

[0041] The lifting mechanism of the device can adjust the longitudinal position of the tensioning section, and can be telescopic, so that the jack can adjust the longitudinal position and vertical position of the tensioning section, the number of times of installing and carrying the jack on the support by the construction personnel is reduced, and the problem of difficult adjustment of the position of the prestressed jack in the free space is solved.

[0042] The rotating mechanism of the device can adjust the angle during construction, ensures that the jack is parallel to the axis of the steel strand, prevents the tensioning end from being damaged due to eccentric force, ensures that the effective prestress after tensioning meets the design and specification requirements, and solves the problem that the jack is difficult to keep parallel to the axis of the steel strand. BRIEF DESCRIPTION OF DRAWINGS

[0043] The present application will be further described below in combination with the drawings and examples.

[0044] Figure 1 is a perspective view of a preferred embodiment of the present application;

[0045] Figure 2 is a perspective view of a steel guide rail connecting embedded bolt of the present application;

[0046] Figure 3 is a partial enlarged view of a nut connected to the embedded bolt of the present application;

[0047] Figure 4 is a front view of the lifting mechanism of the present application;

[0048] Figure 5 is a perspective view of the rotating mechanism of the present application;

[0049] Figure 6 is a partial internal schematic view of the trolley of the present application;

[0050] Figure 7 is a flowchart of the jack positioning auxiliary device and positioning method of the present application.

[0051] In the drawings:

[0052] 1. Steel guide rail; 2. Embedded bolt; 3. Nut; 4. Cast-in-place box girder; 5. Sliding mechanism; 51. Cart; 52. Rotating shaft; 53. Wheel; 54. Through slot; 55. First rectangular slot; 56. Lifting block; 57. L-slot; 58. First support slot; 59. Connecting rod; 593. Isosceles trapezoidal slot; 594. Longitudinal steel beam; 595. Steel column; 596. Steel guide beam; 597. Diagonal steel beam; 598. Inclined slot; 599. Movable hole; 6. Lifting mechanism; 61. Steel hoisting cylinder; 62. Upright; 63. Fixing block; 64. Support pad; 65. Slot hole; 66. First hand-tightening bolt; 7. Rotating mechanism; 71. Rotating hole; 72. Bushing; 73. Rotating shaft; 74. Base; 75. Fixing ring; 76. Threaded hole; 77. Second through hole; 78. Second hand-tightening bolt. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0054] like Figures 1-6 As shown, the present invention provides a jack positioning auxiliary device and positioning method, comprising:

[0055] Steel guide rail 1 is fixed to the top of cast-in-place box girder 4 by a combination of pre-embedded bolts 2 and nuts 3;

[0056] A sliding mechanism 5 is slidably disposed between two sets of steel guide rails 1, and the sliding mechanism 5 is adapted to slide left and right along the two sets of steel guide rails 1;

[0057] A lifting mechanism 6 is vertically slidably mounted on the sliding mechanism 5, and the lifting mechanism 6 is adapted to slide back and forth along the sliding mechanism 5;

[0058] The rotating mechanism 7 is rotatably mounted at the bottom of the lifting mechanism 6. The rotating mechanism 7 is used to install the jack and is suitable for adjusting the angle of the jack. Specifically, a steel guide rail 1 is set on the cast-in-place box girder, and then a sliding mechanism 5 is installed. This does not occupy the space on the open surface working frame. It allows the jack to adjust the lateral position of the jack at the tension section of the cast-in-place box girder 4. At the same time, it can also prevent the workers from passing through the jack support or trolley during construction, ensuring the safety of the workers and solving the problem of small working space at the tension end of the cast-in-place box girder 4.

[0059] Furthermore, the lifting mechanism 6 of the device can adjust the longitudinal position of the sliding mechanism 5 and can extend and retract, so that the jack can adjust the longitudinal and vertical positions of the tension section, reducing the number of times the workers need to install and move the jack on the support, and solving the problem that the position adjustment of the prestressed jack at the free surface is difficult.

[0060] And the device rotating mechanism 7 can adjust the angle in construction, ensure the jack and the steel strand axis parallel, prevent the tensioning end damage due to eccentric force, ensure the effective prestress after tensioning meet the design, specification requirements, solve the problem of jack and steel strand axis difficult to keep parallel.

[0061] Optionally, the sliding mechanism 5 comprises a board car 51 between the two steel rails 1, a plurality of rotating shafts 52 are arranged on both sides of the board car 51 in a mirror image, and a plurality of wheels 53 are arranged on the rotating shafts 52.

[0062] The plurality of wheels 53 are arranged in two rows on the two steel rails 1.

[0063] The inner cavity of the steel rail 1 is arranged in a transverse convex shape. Specifically, the rotating shaft 52 and the wheel 53 can drive the board car 51 to move by rotating the steel rail 1 through friction, and the lifting mechanism 6 and the rotating mechanism 7 can also move transversely with the board car 51. The board car 51 can ensure the stability of the whole device by applying load, and the shape of the steel rail 1 ensures the limiting effect of the moving position of the board car 51, so that the wheel 53 cannot deviate from the steel rail 1 in the longitudinal track.

[0064] Optionally, the sliding mechanism 5 further comprises a through groove 54 arranged transversely on the board car 51, a first rectangular groove 55 arranged on one side of the through groove 54, a lifting block 56 arranged in the first rectangular groove 55, an L-shaped groove 57 arranged on one side of the through groove 54, a first support groove 58 arranged on the lifting block 56, a first support block slidingly arranged in the L-shaped groove 57, a second support block slidingly arranged in the first support groove 58, and a connecting rod 59 arranged between the first support block and the second support block.

[0065] The first rectangular groove 55 is provided with a rotating hole for connecting one of the rotating shafts 52.

[0066] Sliding the connecting rod 59, the first support block and the second support block can be transversely slid along the L-shaped groove 57 and the first support groove 58, respectively, so that the first support block can drive the lifting block 56 to descend after being vertically slid along the L-shaped groove 57. Specifically, the through groove 54 provides a containing space for manual operation, the two side walls of the first rectangular groove 55 are in close contact with the two side walls of the lifting block 56, and the height of the first rectangular groove 55 is greater than the height of the lifting block 56, so that the lifting block 56 can be limited to ascend and descend. The L-shaped groove 57, the first support groove 58 and the first rectangular groove 55 are located on the same plane, the transverse part of the L-shaped groove 57 provides space for the transverse movement of the first support block, and the first support groove 58 provides space for the transverse movement of the second support block. When the first support block is located in the transverse part of the L-shaped groove 57, the first support block, the second support block and the connecting rod 59 are suspended and positioned by the first support groove 58. When the first support block is located at the end of the transverse part of the L-shaped groove 57, the first support block begins to freely fall in the vertical part of the L-shaped groove 57, and the second support block, the connecting rod 59 and the first support groove 58 drive the lifting block 56 to descend and abut against the rotating shaft 52. At this time, the wheel 53 connected with the rotating shaft 52 is positioned by abutment and cannot move, and the transverse position of the jack is also firmly positioned.

[0067] Optionally, the lower end of the lifting block 56 is provided with an isosceles trapezoidal groove 593 which is narrow at the top and wide at the bottom;

[0068] The isosceles trapezoidal groove 593 is collinear with the vertical midline of the rotating hole 71;

[0069] The lifting block 56 can drive the isosceles trapezoidal groove 593 to abut against the rotating shaft 52. Specifically, the isosceles trapezoidal groove 593 can abut against the rotating shaft 52 from multiple angles in the symmetric direction, so that the process of the rotating shaft 52 being abutted has a process from loose to tight, and the force bearing surface of the rotating shaft 52 is increased, so that the abutting process of the rotating shaft 52 is more balanced and the abutting effect is better.

[0070] Optionally, the sliding mechanism 5 further comprises a longitudinal steel beam 594 arranged on the board cart 51, a steel stand column 595 arranged on the longitudinal steel beam 594, a steel guide beam 596 arranged at the top of the steel stand column 595, an inclined steel beam 597 arranged between the steel guide beam 596 and the board cart 51, an inclined groove 598 arranged on the inclined steel beam 597, and a movable hole 599 arranged on the steel guide beam 596;

[0071] The walls of the inclined groove 598 can be in close contact with the two sides of the longitudinal steel beam 594 and the two sides of the steel stand column 595, respectively;

[0072] The lifting mechanism 6 is slidingly connected to the movable hole 599. Specifically, the inclined steel beam 597 and the inclined chute 598 can increase the firmness of the mutual connection of the longitudinal steel beam 594, the steel stand column 595 and the steel guide beam 596, so that the steel stand column 595 can be better supported by the inclined steel beam 597, and the lifting mechanism 6 and the rotating mechanism 7 are provided with good preparation conditions to ensure the rationality of the overall stress of the device. The movable hole 599 reserves a moving space for the lifting mechanism 6, so that the jack can adjust the longitudinal position of the cast-in-place box girder 4 based on this, so that the jack can maintain a suitable distance from the cast-in-place box girder 4, and facilitate the adjustment of contact with the steel strand.

[0073] Optionally, the lifting mechanism 6 comprises a steel lifting cylinder 61 arranged in the movable hole 599, a vertical rod 62 arranged in the steel lifting cylinder 61, a fixed block 63 arranged at the top end of the steel lifting cylinder 61, and a support pad 64 arranged at the bottom end of the steel lifting cylinder 61.

[0074] The fixed block 63 can abut against the steel guide beam 596.

[0075] The steel lifting cylinder 61 can move forward and backward in the movable hole 599.

[0076] The vertical rod 62 can drive the support block to ascend and descend along the steel lifting cylinder 61. Specifically, the fixed block 63 provides a limiting action for the steel lifting cylinder 61 in the vertical direction, so that the steel lifting cylinder 61 will not fall from the movable hole 599 when moving longitudinally in the movable hole 599. The vertical rod 62 can ascend and descend in the steel lifting cylinder 61, so as to control the height of the jack, so that the jack can meet the needs of steel strand prestress testing at different height positions, so as to facilitate the prestress tensioning of the steel strand at different heights of the box girder top plate and the bottom plate. The support pad 64 provides conditions for the rotating installation of the rotating mechanism 7.

[0077] Optionally, the lifting mechanism 6 further comprises a strip hole 65 arranged in the steel lifting cylinder 61, and a first hand screw bolt 66 penetrating through the strip hole 65 and screwing the vertical rod 62.

[0078] The handle of the first hand screw bolt 66 is larger than the width of the strip hole 65.

[0079] The first hand screw bolt 66 can screw against the strip hole 65. Specifically, the height of the strip hole 65 limits the ascending and descending movement space of the vertical rod 62 and the first hand screw bolt 66, so that the movement range of the vertical rod 62 and the support pad 64 is ensured within an interval. After the height of the vertical rod 62 and the first hand screw bolt 66 is changed, the first hand screw bolt 66 can be rotated to abut against the outer wall of the steel lifting cylinder 61, so that the height position of the support pad 64 is locked, and the jack can work better after adjusting the height.

[0080] Optionally, the rotating mechanism 7 comprises a rotating hole 71 arranged on one side of the supporting pad 64, a shaft sleeve 72 arranged in the rotating hole 71, a rotating shaft 73 rotatably arranged in the shaft sleeve 72, the rotating shaft 73 being a combination of two cylindrical bodies with different sizes, an external base 74 arranged on the other side of the rotating shaft 73, and a fixing ring 75 arranged on the upper end of the base 74;

[0081] The jack is arranged on the base 74 through a fixing bolt, and the jack is arranged in the fixing ring 75.

[0082] The jack can be adjusted in angle with the base 74, specifically, the rotating hole 71 provides mounting space for the shaft sleeve 72, the shaft sleeve 72 provides rotating connection space for the rotating shaft 73, based on the function of the rotating shaft 73, the base 74 and the fixing ring 75 can be rotated, so that the jack is convenient for accurate angle adjustment, so as to ensure that the axis of the jack and the axis direction of the steel strand are parallel during prestressed tensioning, so as to balance the stress state of the steel strand and improve the safety of the tensioning process, the jack is mounted on the base 74 and is reinforced through the limiting effect of the fixing ring 75, so that the working position is stable and accurate when the jack works under a relative force.

[0083] Optionally, the rotating mechanism 7 further comprises a threaded hole 76 arranged through the supporting block and the rotating hole 71, a second through hole 77 arranged on the shaft sleeve 72, and a second hand screw bolt 78 inserted through the threaded hole 76 and the second through hole 77.

[0084] The second hand screw bolt 78 can abut against the rotating shaft 73, specifically, the rotating shaft 73 rotates with the angle adjustment of the base 74 and the jack, at this time, the second hand screw bolt 78 can be rotated along the screw thread of the threaded hole 76 to increase the insertion depth in the second through hole 77, until the second hand screw bolt 78 abuts against the rotating shaft 73 to lock the adjustment work of the base 74, so that the angle of the jack does not change.

[0085] As shown in FIG. 1, Figure 7 In another embodiment of the present application, a jack positioning auxiliary device and positioning method are provided, comprising the following steps:

[0086] Firstly, a steel guide rail is installed on the top of the cast-in-place box girder.

[0087] Secondly, a sliding mechanism is connected with the steel guide rail, a lifting mechanism is connected with the sliding mechanism, a rotating mechanism is connected with the lifting mechanism, a jack is installed on the rotating mechanism, then the sliding mechanism is moved to adjust the lateral position of the jack in the tensioning section of the cast-in-place box girder and is fixed, the lifting mechanism is moved to adjust the longitudinal position of the jack through the rotating mechanism, the lifting mechanism is moved to the outermost side of the sliding mechanism, the height of the rotating mechanism is adjusted through the lifting mechanism and is locked.

[0088] Third, adjust the angle of the rotating mechanism and lock the angle of the jack, ensure that the jack is fixed on the anchor pad plate and then start the tensioning operation.

[0089] The above is the ideal embodiment of the present application, and the above description can be varied and modified without departing from the technical concept of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined by the scope of the claims.

Claims

1. A jack positioning auxiliary device, characterized in that, include: Steel guide rail (1) is fixed to the top of cast-in-place box girder (4) by a combination of pre-embedded bolts (2) and nuts (3); A sliding mechanism (5) is slidably disposed between two sets of steel guide rails (1), and the sliding mechanism (5) is adapted to slide left and right along the two sets of steel guide rails (1); A lifting mechanism (6) is vertically slidably mounted on the sliding mechanism (5), and the lifting mechanism (6) is adapted to slide back and forth along the sliding mechanism (5); Rotating mechanism (7), which is rotatably disposed at the bottom of the lifting mechanism (6), is used to install the jack and is adapted to adjust the angle of the jack; The sliding mechanism (5) includes a trolley (51) between two steel guide rails (1), a plurality of rotating shafts (52) arranged in two sets of mirror rotation on both sides of the trolley (51), and a plurality of wheels (53) arranged on the plurality of rotating shafts (52). Several of the wheels (53) are arranged in two rows on the two steel guide rails (1); The inner cavity of the steel guide rail (1) is configured as a transverse convex shape; The sliding mechanism (5) further includes a longitudinal steel beam (594) disposed on the trolley (51), a steel column (595) disposed on the longitudinal steel beam (594), a steel guide beam (596) disposed at the top of the steel column (595), an inclined steel beam (597) disposed between the steel guide beam (596) and the trolley (51), an inclined groove (598) disposed on the inclined steel beam (597), and a movable hole (599) disposed on the steel guide beam (596). The walls of the inclined groove (598) can respectively fit against both sides of the longitudinal steel beam (594) and both sides of the steel column (595); The lifting mechanism (6) is slidably connected to the movable hole (599); The lifting mechanism (6) includes a steel cylinder (61) inserted through the movable hole (599), a vertical rod (62) inserted inside the steel cylinder (61), a fixing block (63) set at the top of the steel cylinder (61), and a support pad (64) set at the bottom of the steel cylinder (61). The fixing block (63) can abut against the steel guide beam (596). The steel cylinder (61) is capable of moving back and forth through the movable hole (599); The upright (62) can drive the support pad to rise and fall along the steel cylinder (61); The lifting mechanism (6) also includes a slot (65) provided in the steel cylinder (61), through which a first hand-tightening bolt (66) passes and is screwed to the upright (62). The handle of the first hand-tightening bolt (66) is larger than the width of the slot (65); The first hand-tightening bolt (66) can spirally abut against the slot (65); The rotating mechanism (7) includes a rotating hole (71) disposed on one side of the support pad (64), a bushing (72) disposed in the rotating hole (71), a rotating shaft (73) rotatably disposed in the bushing (72), a base (74) disposed on the outside of the other side of the rotating shaft (73), and a fixing ring (75) disposed on the upper end of the base (74). The jack is mounted on the base (74) by fixing bolts, and the jack is located inside the fixing ring (75); The jack can be adjusted in angle by rotating with the base (74); The rotating mechanism (7) further includes a threaded hole (76) that passes through the support pad and the rotating hole (71), a second through hole (77) that is provided on the bushing (72), and a second hand-tightening bolt (78) that passes through the threaded hole (76) and inserts into the second through hole (77). The second hand-tightened bolt (78) can abut against the rotating shaft (73).

2. The jack positioning auxiliary device as described in claim 1, characterized in that, The sliding mechanism (5) further includes a through groove (54) arranged laterally on the board car (51), a first rectangular groove (55) arranged on one side of the through groove (54), a lifting block (56) arranged in the first rectangular groove (55), an L groove (57) arranged on one side of the through groove (54), a first support groove (58) arranged on the lifting block (56), a first support block slidably arranged in the L groove (57), a second support block slidably arranged in the first support groove (58), and a connecting rod (59) arranged between the first support block and the second support block. The first rectangular groove (55) is provided with a rotating hole for connecting one of the rotating shafts (52); By sliding the connecting rod (59), the first support block and the second support block can slide laterally along the L groove (57) and the first support groove (58) respectively, so that the first support block can slide vertically along the L groove (57) and drive the lifting block (56) to descend.

3. The jack positioning auxiliary device as described in claim 2, characterized in that, The lower end of the lifting block (56) is provided with an isosceles trapezoidal groove (593) that is narrow at the top and wide at the bottom. The isosceles trapezoidal groove (593) is collinear with the vertical centerline of the rotating hole (71); The lifting block (56) can drive the isosceles trapezoidal groove (593) to abut the rotating shaft (52).

4. The positioning auxiliary device for a jack as described in any one of claims 1-3, wherein the positioning method is as follows: S1, When constructing the cast-in-place box girder (4), the line is measured and the pre-embedded bolts (2) are embedded. After the cast-in-place box girder (4) is poured and reaches the strength required for tensioning, the two sets of steel guide rails (1) are connected to the top of the cast-in-place box girder (4) by the combination of pre-embedded bolts (2) and nuts (3). S2, install the sliding mechanism (5) on the two sets of steel guide rails (1), keep the lifting mechanism (6) extended and connect it to the rotating mechanism (7) and the sliding mechanism (5) respectively, and install the jack on the rotating mechanism (7); S3, by moving the jack, the sliding mechanism (5) slides on the two sets of steel guide rails (1) to adjust the lateral position of the jack at the tension section of the cast-in-place box girder (4). During the movement, the lifting mechanism (6) needs to be moved to the outermost side of the sliding mechanism (5) in advance to ensure that the entire jack adjustment device will not collide with the steel strand to be tensioned. After the lateral position of the jack is aligned, the position of the sliding mechanism (5) is fixed. S4, by adjusting the lifting mechanism (6), the height of the rotating mechanism (7) is adjusted and locked, so that the jack is at the same height as the steel strand. The longitudinal position of the jack is adjusted by moving the lifting mechanism (6), and the angle of the jack is adjusted by rotating the mechanism (7) to ensure that the jack is fixed on the anchor plate, and then tensioning is performed. S5. If it is necessary to continue tensioning other steel strands after tensioning is completed, repeat steps S3-S4 for construction.

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