CN210104588U - Bridge construction pushing device suitable for curves and longitudinal and transverse slopes - Google Patents

Abstract

The utility model provides a bridge construction thrustor suitable for curve and vertical and horizontal slope relates to the technical field of bridge construction, aims at solving current thrustor and is not provided with vertically, transversely and curve regulation structure, leads to its unable construction needs that satisfy vertical and horizontal slope and curved bridge. The device comprises a slide way, a slide box is arranged on the slide way in a sliding manner, a jacking top is vertically arranged in the slide box, the lower wall of the jacking top is arranged on the bottom wall of the slide box in a sliding manner, a jacking top is horizontally arranged on the slide way, a cylinder body and a piston rod of the jacking top are respectively connected onto the slide way and the slide box, a deviation rectifying top is horizontally arranged on the slide box perpendicular to the jacking top, the cylinder body of the deviation rectifying top is fixed on the outer side of the slide box, the piston rod top is arranged on the side wall of the jacking top, an upper seat is arranged above the jacking top, a ball hinge structure is arranged between the upper seat and the jacking top, and. The utility model discloses have the slope of self-adaptation vertical and horizontal slope and the curved change of bridge, ensure the even effect of thrustor atress.

Description

Bridge construction pushing device suitable for curves and longitudinal and transverse slopes

Technical Field

The utility model belongs to the technical field of the technique of bridge construction and specifically relates to a bridge construction thrustor suitable for curve and vertical and horizontal slope is related to.

Background

In the existing pushing construction technology of the bridge body, bridge line deviation can be generated due to uneven load and the like, so that the real-time deviation correction of the bridge body becomes a difficult problem. The general deviation rectifying method is as follows: the side surface of the beam body is provided with a deviation rectifying point, when the beam body is measured to have a deviation, the bridge deck pushing operation is stopped, the deviation is rectified according to the direction and the size of the deviation, and the pushing operation can be continued after the deviation rectification is finished, so that the deviation rectifying mode can greatly increase the pushing operation time and reduce the construction efficiency.

In order to solve the problems, the utility model with the publication number of CN107841957A discloses a large-tonnage steel box girder pushing device, pushing system and pushing method, the pushing device includes jacking telescopic equipment, flat-pushing telescopic equipment and deviation-correcting telescopic equipment, jacking equipment, flat-pushing telescopic equipment and deviation-correcting telescopic equipment are all installed on the sliding box body, the bottom of the sliding box body is provided with a sliding base for sliding, and the two ends of the flat-pushing telescopic equipment and the deviation-correcting telescopic equipment which stretch relatively are connected to the sliding box body and the sliding base respectively.

The jacking device comprises a jacking oil cylinder, a jacking oil cylinder and a jacking oil cylinder, wherein the jacking oil cylinder is arranged on the jacking oil cylinder; the moving direction of the steel box girder to the target position is a longitudinal direction, the telescopic direction of the horizontal pushing telescopic equipment is the same as the longitudinal direction, and the steel box girder is moved to the target position through the pushing of the horizontal pushing telescopic equipment; when the steel box girder is subjected to position deviation in the moving process, the deviation-correcting telescopic equipment of the pushing device pushes the steel box girder to move left and right, so that position adjustment is carried out, and the steel box girder is ensured to be in the correct longitudinal moving direction.

However, in the actual construction process, some bridges often need to be provided with certain longitudinal slopes, transverse slopes or curves, so that the bottom plate of the beam body also has certain longitudinal slopes and transverse slopes, and when the device is used for pushing, the jacking equipment is easily damaged due to uneven stress of the jacking equipment because the upper end of the jacking equipment is horizontally arranged, so that normal construction is delayed. Therefore, longitudinal and transverse leveling structures are required to be arranged on the pushing devices, so that the pushing devices are suitable for construction requirements of bridges at longitudinal and transverse slopes and curves.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a bridge construction thrustor suitable for curve and vertical and horizontal slope, its slope that can the self-adaptation longitudinal and transverse slopes and the curved change of bridge ensure that the thrustor atress is even.

The above utility model discloses an above-mentioned utility model purpose can realize through following technical scheme:

the utility model provides a bridge construction thrustor suitable for curve and vertical and horizontal slope, includes the slide, it is provided with the slip box to slide on the slide, the vertical jacking top that is provided with in the slip box, the lower wall on jacking top slide set up in on the diapire of slip box, the slide is improved level and is provided with the jacking top, the cylinder body and the piston rod of jacking top connect respectively in on slide and the slip box, the slip box is last perpendicular to the jacking top level is equipped with the top of rectifying, the cylinder body of rectifying the top is fixed in the slip box outside, on the lateral wall on jacking top is located to the piston rod top, jacking top is equipped with the seat, the top surface of seat is established to the plane, the seat of honour with be equipped with the ball pivot structure between the jacking top, the seat of honour locate the top of ball pivot structure, the seat of honour with be equipped with limit.

By adopting the technical scheme, in the jacking process of the bridge body, the top surface of the upper seat is in contact with the bottom wall of the bridge body to apply force, the jacking top is used for controlling the sliding box to move in the horizontal direction, the horizontal direction is the extending direction of the bridge in the actual construction process, the jacking top is used for jacking the bridge body, when the bridge body deviates transversely in the ascending process, the deviation rectifying top is started to correct the position of the jacking top, the jacking top drives the bridge body to move together to enable the bridge body to be in the correct position, in the erection process of the bridge body, when a longitudinal and transverse slope section or a curved bridge section of the bridge needs to be constructed, the bottom surface of the bridge body is in an inclined state, and as the spherical hinge structure is arranged in the device and the top of the upper seat is arranged at the top of the spherical hinge structure, the spherical hinge structure can adjust the angle of the spherical hinge structure according to the inclination of the upper seat, the top surface and the upper seat of the top seat are always in a laminating contact state, stable support of the upper seat in an inclined state is achieved, the limiting structure is used for limiting the upper seat when the upper seat inclines, sliding of the upper seat is prevented, the position where the spherical hinge structure is located can be limited, falling of the spherical hinge structure is avoided, the pushing device has self-adaptability to the gradient of a longitudinal slope and a transverse slope of a bridge and the change of a curve of the bridge, accurate pushing of a bridge beam body can be performed in construction of the longitudinal slope and the transverse slope of the bridge, and meanwhile, the top of a piston rod on the top of a jacking top can be kept to be uniformly stressed.

The utility model discloses further set up to: the spherical hinge structure comprises a spherical core with a spherical lower end face and a planar upper end face, a groove matched with the spherical part of the spherical core is formed in the center of the end part of a piston rod of the jacking top, and the upper seat is tightly attached to the planar part of the spherical core.

Through adopting above-mentioned technical scheme, the sphere top of ball core lower extreme is located in the recess, when the seat of honour on the ball core up end when the atress takes place the incline because the slope of bridge beam body, the effect of this incline is used for on the ball core, make the ball core take place to rotate in the recess, thereby play the effect of the slope of the vertical and horizontal slope of self-adaptation bridge, but the ball core is in the position of the centre of sphere with the area of contact of recess remains unchanged and the atress concentration point of ball core all the time rotating process, therefore its whole atress is even, better load-carrying effect has.

The utility model discloses further set up to: the interior shape of the groove is a concave spherical surface that is in close contact with the spherical surface portion of the core.

Through adopting above-mentioned technical scheme, the ball core is closely laminated with the inner wall of recess all the time at the rotation in-process to make ball core and recess whole atress in fitting surface department, reduced local stress concentration.

The utility model discloses further set up to: the groove is a vertical cylindrical hole, and the diameter of the cylindrical hole is smaller than that of the maximum circle on the spherical part of the ball core.

Through adopting above-mentioned technical scheme, the ball core only closely laminates with the top edge in cylinder hole all the time at the rotation in-process, and area of contact is less, therefore the sliding friction between ball core and the recess is less, and the rotation of ball core in the recess is more smooth.

The utility model discloses further set up to: the limiting structure comprises kidney-shaped grooves which are oppositely formed in two opposite side walls of the sliding box and sliding columns which are arranged in the kidney-shaped grooves in a sliding mode, the diameters of the sliding columns are smaller than the widths of the kidney-shaped grooves, the kidney-shaped grooves are vertically arranged, the two sliding columns are arranged in parallel and are respectively located on two sides of the jacking top, the middle of each sliding column penetrates through the upper seat, two ends of each sliding column penetrate through the kidney-shaped grooves respectively, and stopping pieces are arranged at penetrating ends of the sliding columns respectively.

By adopting the technical scheme, when the upper seat inclines under the action of the bridge body, the sliding columns slide up and down in the kidney-shaped groove along with the inclination of the upper seat, and the two ends of the two sliding columns and the two ends of each sliding column can slide asynchronously, so that the effect that the upper seat is limited to incline by a large margin beyond the limited range of the kidney-shaped groove is realized, and the effect that the upper seat inclines in a small-amplitude range can be ensured.

The utility model discloses further set up to: the stop piece comprises a stop piece with the shape larger than the width of the waist-shaped groove and stop pins which are perpendicular to the length direction of the sliding column and penetrate through the two ends of the sliding column, and the distance between each stop pin and the outer side wall of the sliding box is larger than the thickness of the corresponding stop piece.

By adopting the technical scheme, the stop pieces are limited by the stop pins from the two end parts of the sliding column, and can only move between the side wall of the sliding box and the stop pins, when the sliding column slides in the inclination process of the upper seat, the stop pieces can fix the sliding column in a certain sliding range, so that the sliding column is prevented from sliding and falling off, and meanwhile, because the distance between the stop pins and the outer side wall of the sliding box is greater than the thickness of the stop pieces, the upper seat cannot be locked by the stop pieces on the two sides, but can incline and move in a certain range, so that the upper seat is suitable for the slope section and the curvature of a bridge.

The utility model discloses further set up to: the piston rod of jacking top includes with piston lug connection's piston cylinder and threaded connection in the piston core in the piston cylinder, the recess is located the top of piston core, the upper portion of piston core still is equipped with the drive the flexible application of force structure of piston core.

By adopting the technical scheme, when the height of the bridge body to be jacked is lower, the piston core can be driven to descend through the force application structure, so that the piston core enters the piston cylinder, and the bridge body is jacked only by utilizing the height of the piston cylinder; when the height of the bridge body needing jacking is higher, the piston core can be driven to ascend by the force application structure, so that the bridge body is jacked higher in the jacking stroke.

The utility model discloses further set up to: the force application structure comprises jacks which penetrate through the piston core along the diameter direction of the cross section of the piston core, and at least two jacks are arranged in a crossed mode.

Through adopting above-mentioned technical scheme, personnel can through insert spanner or other application of force member and locate the jack, order about the piston core at the piston cylinder internal rotation through rotating the member to make the piston core rise or descend, simple structure, convenient to use, the mode that two at least jacks alternately set up makes personnel can follow when rotating the member and make the piston core take place to rotate through the mode of switching the jack with one side, thereby realize the rising or the decline of piston core, personnel's operation has further been made things convenient for.

To sum up, the utility model discloses a beneficial technological effect does:

1. the upper seat is arranged above the jacking top, the spherical hinge structure is arranged between the upper seat and the jacking top, and the limiting structure is arranged between the upper seat and the sliding box, so that the device has self-adaptability to the gradient of a longitudinal and transverse slope of a bridge and the change of a curve of the bridge, the accurate jacking of a bridge body is realized in the construction of the longitudinal and transverse slope or a curve bridge, and the uniform stress on the top of a piston rod of the jacking top can be kept;

2. the piston rod of the jacking top is in threaded sleeve connection with the piston cylinder and the piston core, so that the jacking height of the jacking top is increased, and the applicability of the device is improved.

Drawings

Fig. 1 is a schematic view of an overall structure of a first embodiment of a bridge construction pushing device suitable for curved and longitudinal and transverse slopes disclosed by the present invention.

Fig. 2 is a sectional view a-a in fig. 1.

Fig. 3 is a structural cross-sectional view of a second embodiment of the bridge construction pushing device suitable for curved and longitudinal and transverse slopes disclosed by the present invention.

In the figure, 1, a slideway; 2. a slide box; 3. pushing; 4. jacking a deviation correcting device; 5. jacking and jacking; 51. a piston cylinder; 52. a piston core; 6. an upper seat; 7. a spherical hinge structure; 71. a ball core; 72. a groove; 8. a limiting structure; 81. a traveler; 82. a kidney-shaped groove; 83. a stopper; 831. a stopper piece; 832. a stop pin; 9. a force application structure; 91. a jack; 10. a chute; 11. a slide bar.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example one

Referring to fig. 1 and 2, in order to disclose the bridge construction pushing device suitable for curves and longitudinal and transverse slopes, the bridge construction pushing device comprises a slide way 1, a slide box 2 with an opening at the upper end is arranged on the slide way 1 in a sliding manner, a pushing top 3 is horizontally arranged on the slide way 1 along the extending direction of the slide way 1, a cylinder body of the pushing top 3 is fixedly connected to the slide way 1, and a piston rod is fixedly connected to the slide box 2; the lifting jack 5 is vertically arranged in the sliding box 2, two deviation rectifying jacks 4 are horizontally arranged on two sides of the sliding box 2 perpendicular to the lifting jack 3, cylinder bodies of the deviation rectifying jacks 4 are respectively fixed on the outer side of the sliding box 2, a piston rod jack is arranged on the side wall of the lifting jack 5, in order to ensure that the lifting jack 5 slides and moves along the direction perpendicular to the slide way 1 under the action of the deviation rectifying jacks 4, a sliding groove 10 is formed in the side wall of the sliding box 2 in parallel with the ejection direction of the deviation rectifying jacks 4, sliding rods 11 are fixedly connected to two sides of the lifting jack 5, and the sliding rods 11 are arranged in the sliding. An upper seat 6 is arranged above the jacking top 5, the top surface of the upper seat 6 is arranged to be a plane and used for jacking a bridge body, a spherical hinge structure 7 is arranged between the upper seat 6 and the jacking top 5, the top of the spherical hinge structure 7 is arranged at the top of the upper seat 6, and a limiting structure 8 is arranged between the upper seat 6 and the sliding box 2.

The utility model discloses use the top of steel case roof beam to push the process as the example in this embodiment to explain the use of this device.

In the jacking process of the steel box girder, firstly, jacking positions of the jacking devices are set according to the structure of the bridge, then a plurality of jacking devices are placed on the bridge piers at preset positions and are fixed, wherein pad girders are respectively arranged on two sides of the jacking devices, and a slide way 1 of each jacking device is parallel to the extending direction of the bridge; the action sequence of the pushing device is as follows: the jacking top 5 jacks up the steel box girder, then the jacking top 3 jacks out the slide box 2 by a distance of one stroke, then the jacking top 5 descends to separate from the steel box girder and place the steel box girder on the pad girder, the jacking top 3 retracts by one stroke to return to the original position, and then the action sequence is repeated to enter the next jacking. When the transverse deviation of the steel box girder in the lifting process is monitored, the jacking action of the jacking roof 5 needs to be stopped in time, the deviation rectifying roof 4 needs to be started, the deviation rectifying roof 4 pushes the jacking roof 5 to drive the steel box girder to move together, and the jacking roof 5 can be started again to work after the steel box girder is in the correct position.

In the erecting process of the steel box girder, when a bridge with a longitudinal cross slope or a bend is encountered, the steel box girder needs to have a certain gradient, the bottom surface of the steel box girder is also in an inclined state, at the moment, the spherical hinge structure 7 is arranged, and the top of the spherical hinge structure 7 is arranged at the top of the upper seat 6, so that the spherical hinge structure 7 can adjust the angle of the upper seat 6 under the action of gravity of the steel box girder according to the inclination of the upper seat 6, the upper top surface and the upper seat 6 are always in a state of being in contact with each other in a laminating manner, stable support of the upper seat 6 in the inclined state is realized, the limiting structure 8 is used for limiting the upper seat 6 when the upper seat 6 is inclined, the upper seat 6 is prevented from sliding down, meanwhile, the position where the spherical hinge structure 7 is located can also be limited, and the spherical hinge structure 7 is prevented from.

Referring to fig. 1 and 2, the spherical hinge structure 7 includes a spherical core 71 having a spherical lower end surface and a planar upper end surface, a groove 72 fitted with the spherical surface of the spherical core 71 is provided at the center of the end of the piston rod of the jacking ram 5, the inner shape of the groove 72 is a concave spherical surface fitted with the spherical surface of the spherical core 71, and the upper seat 6 is closely fitted with the planar surface of the spherical core 71. In the above structure, the angle of rotation of the core 71 can be set under the condition of ensuring safety according to the pushing requirement.

After the spherical hinge structure 7 and the upper seat 6 are assembled, the spherical surface at the lower end of the spherical core 71 is propped in the groove 72, and when the upper seat 6 on the upper end surface of the spherical core 71 is stressed to incline due to the inclination of the steel box girder, the inclined force acts on the spherical core 71, so that the spherical core 71 rotates in the groove 72, and the function of self-adapting to the gradient of the longitudinal and transverse slopes of the bridge is achieved.

Referring to fig. 1 and 2, the position-limiting structure 8 includes two sets of slots 82 on two opposite side walls of the slide case 2 and a sliding post 81 slidably disposed in the slots 82, each group comprises two kidney-shaped grooves 82, the two kidney-shaped grooves 82 are located at opposite positions on opposite surfaces of the sliding box 2, the diameter of each sliding column 81 is smaller than the width of the corresponding kidney-shaped groove 82, the kidney-shaped grooves 82 are vertically arranged, the sliding columns 81 are arranged in parallel, two sliding columns 81 are respectively located on two sides of the jacking top 5, the middle of each sliding column 81 penetrates through the upper seat 6, two ends of each sliding column penetrate through the corresponding kidney-shaped grooves 82 respectively, stop parts 83 are respectively arranged at the penetrating ends of the corresponding sliding columns, each stop part 83 comprises a stop piece 831 with the shape larger than the width of the corresponding kidney-shaped groove 82 and stop pins 832 perpendicular to the length direction of the corresponding sliding column 81 and arranged at two ends of the corresponding sliding column 81, and the distance between the stop pins 832 on two sides and the outer side.

When the upper seat 6 is inclined by the steel box girder, the sliding columns 81 slide up and down in the kidney-shaped grooves 82 along with the inclination of the upper seat 6, and the two sliding columns 81 and the two ends of each sliding column 81 can slide asynchronously, and when the stopping piece 831 sliding to one end of the sliding column 81 is pushed and arranged between the stopping pin 832 and the side wall of the sliding box 2, the upper seat 6 is difficult to incline again in the direction. The structure realizes the effect of limiting the upper seat 6 to incline by a large margin beyond the limit range of the kidney-shaped groove 82 and ensuring the upper seat 6 to incline in a small margin range, thereby being suitable for the construction of longitudinal and transverse slopes and curve sections of bridges.

Referring to fig. 2, in order to increase the jacking stroke of jacking top 5, improve thrustor's suitability, jacking top 5's piston rod includes piston cylinder 51 and the piston core 52 of threaded connection in piston cylinder 51 with piston lug connection, and recess 72 sets up in piston core 52's top, and piston core 52's upper portion still is equipped with the flexible application of force structure 9 of drive piston core 52, and application of force structure 9 includes the jack 91 that runs through piston core 52 along piston core 52's cross-sectional diameter direction, the utility model discloses jack 91 in this embodiment is alternately provided with two.

When the steel box girder needs to be jacked up to a lower height, the rigid rod piece can be inserted into the jack 91 on the piston core 52, and the rod piece is pushed to drive the piston core 52 to rotate so as to drive the piston core 52 to descend, so that the piston core 52 enters the piston cylinder 51, and the steel box girder is jacked up only by using the height of the piston cylinder 51; when the steel box girder needs to be jacked up to a height higher than the stroke of the piston cylinder 51, a person can also insert the rigid rod into the insertion hole 91 on the piston core 52 and push the rod to carry the piston core 52 to rotate reversely to drive the piston core 52 to ascend, so that the steel box girder is jacked up higher in the stroke of the jacking jack 5.

Example two

The utility model discloses a bridge construction thrustor suitable for curve and vertical and horizontal slope that this embodiment reveals is the same basically with embodiment one, and its difference lies in the shape difference of recess 72, specifically is: referring to fig. 3, the groove 72 is a vertically arranged cylindrical hole having a diameter smaller than that of the largest circle on the spherical portion of the core 71.

The first embodiment of the present invention has the following distinguishing effects: in the first embodiment, the ball core 71 is always tightly attached to the inner wall of the groove 72 in the rotating process, so that the groove 72 is integrally stressed on the matching surface with the ball core 71, local stress concentration is reduced, and the service life of the ball hinge structure 7 is prolonged; in the embodiment, the ball core 71 is only tightly attached to the upper edge of the cylindrical hole all the time in the rotating process, and the contact area is small, so that the sliding friction between the ball core 71 and the groove 72 is small, and the rotation of the ball core 71 in the groove 72 is smoother.

The embodiment of this specific implementation mode is the preferred embodiment of the present invention, not limit according to this the utility model discloses a protection scope, so: all equivalent changes made according to the structure, shape and principle of the utility model are covered within the protection scope of the utility model.

Claims (8)

1. The utility model provides a bridge construction thrustor suitable for curve and longitudinal and transverse slope, includes slide (1), slide (1) is gone up to slide and is provided with slide box (2), the vertical jacking top (5) that is provided with in slide box (2), the lower wall of jacking top (5) slide set up in on the diapire of slide box (2), slide (1) is improved level and is provided with jacking top (3), the cylinder body and the piston rod of jacking top (3) connect respectively in slide (1) and slide box (2) are gone up, the last perpendicular to of slide box (2) jacking top (3) level is equipped with rectifying top (4), the cylinder body of rectifying top (4) is fixed in the slide box (2) outside, the piston rod top is located on the lateral wall of jacking top (5), its characterized in that: jacking top (5) top is equipped with upper bracket (6), the top surface of upper bracket (6) is established to the plane, upper bracket (6) with be equipped with spherical hinge structure (7) between jacking top (5), upper bracket (6) top is located the top of spherical hinge structure (7), upper bracket (6) with be equipped with limit structure (8) between smooth case (2).

2. The bridge construction thrustor suitable for curves and longitudinal and transverse slopes according to claim 1, characterized in that: the spherical hinge structure (7) comprises a spherical core (71) with a spherical lower end face and a planar upper end face, a groove (72) matched with the spherical part of the spherical core (71) is formed in the center of the end part of a piston rod of the jacking top (5), and the upper seat (6) and the planar part of the spherical core (71) are arranged in a clinging mode.

3. The bridge construction thrustor suitable for curves and longitudinal and transverse slopes according to claim 2, characterized in that: the inner shape of the groove (72) is a concave spherical surface that is fitted to the spherical surface portion of the core (71).

4. The bridge construction thrustor suitable for curves and longitudinal and transverse slopes according to claim 2, characterized in that: the groove (72) is a vertical cylindrical hole, and the diameter of the cylindrical hole is smaller than that of the largest circle on the spherical part of the ball core (71).

5. The bridge construction thrustor suitable for curves and longitudinal and transverse slopes according to claim 1, characterized in that: the limiting structure (8) comprises two opposite kidney-shaped grooves (82) formed in two opposite side walls of the sliding box (2) and sliding columns (81) arranged in the kidney-shaped grooves (82) in a sliding mode, the diameter of each sliding column (81) is smaller than the width of each kidney-shaped groove (82), the kidney-shaped grooves (82) are vertically arranged, the two sliding columns (81) are arranged in parallel and are respectively located on two sides of the jacking top (5), the middle of each sliding column (81) penetrates through the upper seat (6), two ends of each sliding column penetrate through the kidney-shaped grooves (82) respectively, and stopping pieces (83) are arranged at penetrating ends of the sliding columns respectively.

6. The bridge construction thrustor suitable for curves and transverse and longitudinal slopes according to claim 5, characterized in that: the stop piece (83) comprises a stop piece (831) with the shape larger than the width of the kidney-shaped groove (82) and stop pins (832) which are perpendicular to the length direction of the sliding column (81) and penetrate through the two ends of the sliding column (81), and the distance between the stop pins (832) and the outer side wall of the sliding box (2) is larger than the thickness of the stop piece (831).

7. The bridge construction thrustor suitable for curves and longitudinal and transverse slopes according to claim 2, characterized in that: the piston rod of the jacking top (5) comprises a piston cylinder (51) directly connected with a piston and a piston core (52) in the piston cylinder (51) in threaded connection, the groove (72) is formed in the top of the piston core (52), and the upper portion of the piston core (52) is further provided with a force application structure (9) for the piston core (52) to stretch and retract.

8. The bridge construction thrustor suitable for curves and transverse and longitudinal slopes according to claim 7, characterized in that: the force application structure (9) comprises insertion holes (91) penetrating through the piston core (52) along the diameter direction of the piston core (52), and at least two groups of insertion holes (91) are arranged in a crossed mode.

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