A hydraulic inner mold template for prefabricated box beam with whole hole

Abstract

The invention discloses a hydraulic inner mold template for a whole hole prefabricated box beam, including an end segment, a variable segment and a middle segment, each segment is divided into a top mold and a movable mold symmetrically hinged on both sides in the template in the circumferential direction, each movable mold is hinged and formed in sequence from the first movable mold to the Nth movable mold, each top mold and movable mold includes a skeleton and a panel, and the inner surface of the panel is completely fitted and fixed with the skeleton; the hinge axis of each movable mold of the variable segment is not parallel to the longitudinal axis of the template. The end surface of the middle segment of the variable segment is a step surface extending from the first movable mold to the Nth movable mold in sequence toward the middle of the beam, and the extension length of the next movable mold is not less than the maximum interference between the previous movable mold and the middle segment space; the mold is closed first, and the outer contour of the part of the movable mold extending into the middle segment space after the middle segment is closed is smaller than the inner contour of the first movable mold panel after the middle segment is closed, and the outer contour of the part extending into the end segment space is smaller than the inner contour of the first movable mold panel after the end segment movable mold is closed.

Description

Technical Field

[0001] The invention belongs to the field of bridge prefabricated formwork, and in particular relates to a hydraulic inner formwork for a whole-hole prefabricated box beam. Background Art

[0002] The inner cavity shape of the whole hole precast concrete box girder is usually similar to a shuttle shape, which is large in the middle and small at both ends. The middle and both ends are equal-section segments. In the design of the box girder inner mold, we name the corresponding template segments as middle segments and end segments according to their locations, and the gradient segment between the middle segment and the end segment is called the variable segment. The space enclosed by the corresponding outer surface of the template when each segment is erected is named the end segment space, the variable segment space and the middle segment space respectively. In order to achieve the overall demoulding effect, the templates of the middle segment and the variable segment of the box girder inner mold after shrinkage must be removed from the end segment space with the smallest cross-section.

[0003] At present, the most commonly used and efficient method in the design of box girder inner mold formwork is: divide the formwork into multiple blocks in the circumferential direction (generally divided into a top mold and multiple movable molds), hinged in pairs, and then rotate and shrink each segment formwork in sequence through a hydraulic control system, so that each segment formwork can finally reach an outer contour that can be completely removed from the end segment space to realize the demoulding of the entire box girder inner mold.

[0004] However, this kind of inner mold template design structure has certain technical difficulties in the demolding process: the variable segments in the template have non-uniform cross-sectional shapes, so if the hinge axis of the variable segment movable mold rotation cannot be designed to be parallel to the length direction of the beam body, then when the movable molds of the variable segments are rotated during mold closing, part of the contour will exceed the variable segment space and turn into the end segment space or the middle segment space, that is, during the entire mold closing process, the two ends of each movable mold of the variable segment may interfere with the adjacent end segment and middle segment templates, and the length of the mutual interference is the interference amount. (Mathematical model of the maximum interference amount: let the projection line of the variable segment centerline be b, the projection of the variable segment movable mold after it is unfolded to the final state be c, and the projection of the variable segment movable mold after it is rotated to the final state be d, e is the perpendicular line from the farthest end of projection c to the projection line b, and the distance F from the farthest end of projection d to the perpendicular line e is the maximum interference amount, such as Fig.10 (shown)

[0005] At present, in the design of the inner formwork of the whole hole prefabricated box beam, the following two design structures are commonly used to avoid this interference phenomenon:

[0006] 1. The interference area is divided into several removable movable templates. Before the hydraulic control demoulding, the movable template needs to be removed first to avoid interference between the variable segment and the end segment or the middle segment during the mold closing process; when erecting the mold, the movable template is manually installed after the hydraulic template is supported in place. Therefore, this structure cannot achieve full hydraulic demoulding of each segment template, and requires manual installation and removal of the movable template, which is time-consuming and labor-intensive, and the installation accuracy is difficult to guarantee, which can easily lead to defects such as misalignment on the beam forming surface.

[0007] 2. In the published Chinese invention patent CN201952740U "Asymmetric box girder hydraulic inner mold", it is mentioned that the top mold on the end segment and the variable segment is hinged to the upper movable mold through a double-hinged ear plate on the top mold and a single-hinged ear plate on the upper movable mold. The single-hinged ear plate is arranged between the double-hinged ear plates and the spacing between the double-hinged ear plates is A. This patent is achieved by setting a spacing A between the double-hinged ear plates on the end segment and the top mold of the variable segment. After the end segment is closed in place, the upper and lower movable molds of the end segment are pulled by external force to slide a distance A relative to the top mold, and then the variable segment is contracted. During the contraction of the variable segment, the extrusion pressure generated between the upper movable mold of the variable segment and the middle segment that has not yet contracted pushes the upper and lower movable molds of the variable segment to slide a distance A relative to the top mold. In this way, the interference between the variable segment and the end segment and the middle segment is avoided. Although this structure can realize the overall demoulding of each segment of the inner mold template, it requires the help of external force, and the actual operation is relatively complicated. In addition, when the hinge of the upper movable mold of the variable segment has a concave-convex shape such as a lifting pedestal, the sliding will be hindered, and the interference between the upper and lower movable molds of the variable segment and the middle segment cannot be avoided in the above manner, which has great limitations. Summary of the invention

[0008] The purpose of the present invention is to provide an inner mold template for a whole-hole prefabricated box beam, which can realize overall hydraulic demoulding without setting a movable template or dragging the template with external force.

[0009] The hydraulic inner mold template for the whole-hole prefabricated box beam provided by the present invention includes an end segment, a variable segment and a middle segment connected in sequence, each segment is divided into a top mold and movable molds symmetrically hinged on both sides of the template in the circumferential direction, and each movable mold is hingedly formed in sequence from the first movable mold to the Nth movable mold according to the shape and size of the inner cavity of the box beam. Each top mold and each movable mold includes a skeleton and a panel, and the inner surface of the panel is completely fitted and fixedly connected to the skeleton; the hinge axes of rotation of each movable mold of the variable segment are not parallel to the longitudinal axis of the template. The connecting end faces of the middle sections of the variable sections are step surfaces that extend out a certain length toward the middle of the beam from the first movable mold to the Nth movable mold, and the extending length of the next movable mold is not less than the maximum interference between the previous movable mold and the middle section space; when closing the mold, the variable section is closed first, and the outer contour of the part extending into the middle section space after the movable mold of the variable section is shrunk into place is smaller than the inner contour formed by the first movable mold panel after the middle section is closed into place, and the outer contour of the part extending into the end section space is smaller than the inner contour formed by the first movable mold panel after the movable mold of the end section is shrunk into place.

[0010] In one embodiment of the above technical solution, the longitudinal length of each movable mold skeleton of the middle segment is smaller than the longitudinal length of the panel, and the length difference between the connected end skeletons of the middle segment and the panel is not less than the maximum interference amount within the thickness range of the movable mold skeleton corresponding to the middle segment during the mold closing process of each movable mold of the variable segment.

[0011] In one embodiment of the above technical solution, the longitudinal length of each movable mold skeleton of the end segment is smaller than the longitudinal length of the panel, and the length difference between the end skeletons connected to the variable segment and the panel is not less than the maximum interference amount within the thickness range of the movable mold skeleton corresponding to the end segment during the mold closing process of each movable mold of the variable segment.

[0012] When closing the mold, the present invention first closes the variable segment, merges a length of the middle segment movable mold into the movable mold connected with the variable segment, and allows the template section on the middle segment movable mold that originally causes interference to be first rotated along with the variable segment movable mold around the hinge axis of the variable segment movable mold into the variable segment space and demolded into place, leaving more space for the remaining middle segment movable mold that rotates parallel to the longitudinal direction of the beam body, thereby avoiding interference between the middle segment movable mold and the variable segment movable mold when demolding. By first closing the mold of the variable segment, then closing the middle segment or the end segment, and then adjusting the position of the hinge axis of the top mold of the variable segment and the first movable mold connected thereto and the subsequent adjacent Nth movable mold, the inner contour of the panel of each first movable mold on the middle segment and the end segment can be completely enveloped by the outer contour of the part of each movable mold on the variable segment extending into the space of the middle segment and the end segment during the whole process from the beginning to the completion of the mold closing of the middle segment and the end segment, so as to avoid the interference of the movable mold panel with the variable segment that has been demolded in place when the middle segment and the end segment are demolded. The structure that the longitudinal length of the movable mold skeleton of the middle segment and the end segment is smaller than the longitudinal length of the panel can avoid the interference of the movable mold skeleton of the middle segment and the end segment in the initial demolding stage.

[0013] In summary, the present invention designs each segment as a whole through the above structure, there is no loose mold, no need to use external force to drag the template, and it is not restricted by the concave and convex shapes of the lifting base, etc., which can avoid various interferences between the variable segment and the middle segment and the end segment during the demolding process of the template. It solves the problem that the box girder inner mold template cannot be hydraulically demolded as a whole when the hinge axis of the variable segment is not parallel to the longitudinal direction of the template, and has achieved good results in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic structural diagram of an embodiment of the present invention.

[0015] Figure 2 for Figure 1 Schematic diagram of the left view structure.

[0016] Figure 3 for Figure 2 Schematic diagram of the structure in the demoulding state when viewed from above (the movable mold at the lower left of the middle section is not shown).

[0017] Figure 4 for Figure 2 Schematic diagram of the structure in the demoulding state when viewed from above (the upper right movable mold of the end segment and the middle segment is not shown).

[0018] Figure 5 It is a schematic diagram of the structure of the end segment and the variable segment in the demoulding state.

[0019] Figure 6 It is a schematic diagram of the structure of the middle segment and the variable segment in the demoulding state.

[0020] Figure 7 for Figure 6 Axonometric structural diagram.

[0021] Figure 8 for Figure 2 Schematic diagram of CC cross section in .

[0022] Fig. 9 It is a schematic diagram of the structure of the variable-segment movable mold in the initial stage of demolding (the left side is the initial stage of demolding of the upper movable mold, and the right side is the initial stage of demolding of the lower movable mold).

[0023] Fig.10 Schematic diagram of the mathematical model of maximum interference.

[0024] Fig.11 Schematic diagram for the definition of sub-slit length.

[0025] Meaning of numbers and letters in the figure:

[0026] 1-terminal segment;

[0027] 11-end segment moving mold; 13-end segment top mold;

[0028] 111-end segment dynamic mold panel; 112-end segment dynamic mold skeleton;

[0029] 2-variable segment;

[0030] 21-variable segment upper movable mold; 22-variable segment lower movable mold; 23-variable segment top mold;

[0031] 3-middle segment;

[0032] 31- middle section upper movable mold; 32- middle section lower movable mold; 33- middle section top mold;

[0033] 311- middle section upper movable mold panel; 312- middle section upper movable mold skeleton;

[0034] 321-middle section lower movable mold panel; 322-middle section lower movable mold skeleton;

[0035] 412-junction surface between the end segment and the variable segment template;

[0036] 423-joining surface between the variable segment and the middle segment template;

[0037] 522-hinged axis of the variable segment top mold and the variable segment upper movable mold;

[0038] 521-hinged axis of the upper movable mold of the variable segment and the lower movable mold of the variable segment;

[0039] F-maximum interference;

[0040] F3-the maximum interference between the moving mold of the middle segment and the variable segment space;

[0041] F1ˊ-The maximum interference between the variable segment dynamic mold and the end segment dynamic mold skeleton;

[0042] F31ˊ-The maximum interference between the movable mold on the variable segment and the movable mold skeleton on the middle segment;

[0043] F32ˊ-The maximum interference between the lower movable mold of the variable segment and the lower movable mold skeleton of the middle segment;

[0044] L-the length of the movable die under the variable segment extending into the space of the middle segment;

[0045] S-sub-seam length;

[0046] S11-length of the movable die seam of the end segment;

[0047] S31-length of movable die seam on middle segment;

[0048] S32-length of the movable mold seam at the middle section. DETAILED DESCRIPTION

[0049] like Figures 1 to 3As shown, the prefabricated box girder hydraulic inner mold formwork disclosed in this embodiment includes an end segment 1, a variable segment 2 and a middle segment 3 which are connected in sequence.

[0050] The end segment 1 is divided into an end segment top mold 13 and an end segment movable mold 11 symmetrically hinged on its left and right sides in the circumferential direction of the template.

[0051] The variable segment 2 is divided into a variable segment top mold 23 and a variable segment upper movable mold 21 and a variable segment lower movable mold 22 symmetrically hinged on its left and right sides in the circumferential direction of the template.

[0052] The middle section 3 is divided into a middle section top mold 33 and a middle section upper movable mold 31 and a middle section lower movable mold 32 symmetrically hinged on its left and right sides in the circumferential direction of the template.

[0053] Each of the top mold, the movable mold, the upper movable mold and the lower movable mold is composed of a panel and a frame, and the inner surface of the panel is completely fitted with and fixedly connected to the frame.

[0054] Adjacent structural members of each segment are connected in a hinged manner.

[0055] like Figure 1 As shown, the junction surface 423 between the variable segment 2 and the middle segment 3 is stepped from top to bottom and from the end segment to the middle segment. The middle segment connecting end of the variable segment lower movable mold 22 has a length L extending into the middle segment space, and the variable segment connecting end of the corresponding middle segment lower movable mold 32 is shortened by the length L to ensure seamless connection between the middle segment lower movable mold 32 and the variable segment lower movable mold 22.

[0056] like Figures 5 to 7 As shown, the hinge axis 522 between the variable segment top mold 23 and the variable segment upper movable mold 21, and the hinge axis 521 between the variable segment upper movable mold 21 and the variable segment lower movable mold 22 are not parallel to the longitudinal direction of the beam body.

[0057] like Figure 3 As shown, when the end segment movable mold 11 is not provided with a sub-gap, the maximum interference amount between the end segment movable mold skeleton 111ˊ and the variable segment upper movable mold 21 during the mold closing process is F1ˊ.

[0058] like Figure 8 As shown, when the middle segment upper movable mold 31 is not provided with a sub-gap, the maximum interference amount between the middle segment upper movable mold skeleton 312ˊ and the variable segment upper movable mold 21 during the mold closing process is F31ˊ, and when the middle segment lower movable mold 22 is not provided with a sub-gap, the maximum interference amount between the middle segment lower movable mold skeleton 322ˊ and the variable segment lower movable mold 32 is F32ˊ.

[0059] like Figure 4 As shown, the maximum interference between the variable segment upper movable mold 21 and the variable segment lower movable mold 22 and the middle segment space during the entire demoulding process of the template is F3, and F3 is less than the length L of the middle segment connecting end of the variable segment lower movable mold 22 extending into the middle segment space.

[0060] For the convenience of description, the concept of "sub-slit" is introduced, such as Fig.11 As shown in the figure, the length difference between the template MB and the skeleton GJ is defined as the sub-slit S, as Fig.11 shown.

[0061] like Figure 8 , Fig. 9 As shown, at the end where the variable segments of the middle segment upper movable mold 31 are connected, the length of the middle segment upper movable mold skeleton 312 is shorter by S31 than the middle segment upper movable mold panel 311. A sub-gap S31 is provided between the middle segment upper movable mold skeleton 312 and the middle segment upper movable mold panel 311 at this end, and the sub-gap width S31 is greater than F31ˊ. At the end where the variable segments 2 of the middle segment lower movable mold 32 are connected, the length of the middle segment lower movable mold skeleton 322 is shorter by S32 than the middle segment lower movable mold panel 321, so that a sub-gap S32 is provided between the middle segment lower movable mold skeleton 322 and the middle segment lower movable mold panel 321 at this end, and the sub-gap width S32 is greater than F32ˊ, so as to avoid interference between the variable segment movable mold and the middle segment upper movable mold skeleton 321 and the lower movable mold skeleton 322 in the initial stage of demoulding.

[0062] like Fig. 9 As shown, at the connected end of the variable segment of the end segment dynamic mold 11, the length of the end segment dynamic mold skeleton 112 is S11 shorter than the end segment dynamic mold panel 111, so that a sub-gap S11 exists between the end segment dynamic mold skeleton 112 and the end segment dynamic mold panel 111 at this end, and the sub-gap width S11 is greater than F1ˊ, so as to avoid interference between the variable segment and the end segment dynamic mold skeleton 112 in the initial stage of demolding.

[0063] The above structure of the template can ensure the overall hydraulic demoulding of the template. The order of closing the mold during demoulding is to close the variable segment 2 first, then the middle segment 3, and finally the end segment 1, as follows:

[0064] like Figure 3 , Figure 6 As shown, when the variable segment 2 is closed, the template of the length L of the middle segment lower movable mold 32 incorporated into the variable segment lower movable mold 22 (the template of the area that would originally interfere) is first rotated into the variable segment space around the hinge axis 521 of the upper and lower movable molds of the variable segment with the variable segment lower movable mold 22 to be demolded into place, leaving more space for the remaining middle segment movable mold that rotates parallel to the longitudinal direction of the template, thereby avoiding interference between the middle segment lower movable mold panel 321 and the middle segment lower movable mold skeleton 322 and the variable segment lower movable mold 22 when the middle segment lower movable mold 32 is demolded.

[0065] like Figure 6 , Figure 7As shown, during the whole process from the beginning to the completion of the mold closing of the middle segment 3, the template portions of the upper movable mold 21 and the lower movable mold 22 of the variable segment that have been molded into place and extend into the space of the middle segment are completely located on the inner side of the upper movable mold panel 311 and the lower movable mold panel 312 of the middle segment in the circumferential direction of the template, that is, the outer contour of the template portions of the upper movable mold 21 and the lower movable mold 22 of the variable segment that extend into the space of the middle segment is smaller than the inner contour of the upper movable mold panel 311 and the lower movable mold panel 321 of the middle segment, thereby avoiding interference between the movable mold panel and the movable mold of the variable segment when the middle segment is demolded.

[0066] like Figure 5 As shown, during the entire process from mold closing to completion of the end segment 1, the template parts of the upper movable mold 21 and the lower movable mold 22 of the variable segment that have been molded into place and extend into the end segment space are completely located on the inner side of the end segment movable mold panel 111 in the template circumferential direction, that is, the outer contour of the template parts of the upper and lower movable molds 21 and 22 of the variable segment that extend into the end segment space is smaller than the inner contour of the end segment movable mold panel 111, thereby avoiding interference between the movable mold panel and the variable segment movable mold when the end segment is demolded.

[0067] In summary, the present invention designs each segment as a whole through the above structure, there is no loose mold, no need to use external force to drag the template, and it is not restricted by the concave and convex shapes of the lifting base, etc., which can avoid various interferences between the variable segment and the middle segment and the end segment during the demolding process of the template. It solves the problem that the box girder inner mold template cannot be hydraulically demolded as a whole when the hinge axis of the variable segment is not parallel to the longitudinal direction of the template, and has achieved good results in practical applications.

Claims

1. A hydraulic inner mold template for a whole hole prefabricated box beam, comprising an end segment, a variable segment and a middle segment connected in sequence, each segment is divided into a top mold and a movable mold symmetrically hinged on both sides in the template in the circumferential direction, each movable mold is hingedly formed in sequence from the first movable mold to the Nth movable mold according to the shape and size of the inner cavity of the box beam, each top mold and each movable mold comprises a frame and a panel, the inner surface of the panel is completely fitted and fixedly connected with the frame; the hinge axis of each movable mold of the variable segment is not parallel to the longitudinal axis of the template, characterized in that: The end surface of the middle segment of the variable segment is a step surface extending from the first movable mold to the Nth movable mold in the direction of the beam, and the extension length of the next movable mold is not less than the maximum interference between the previous movable mold and the middle segment space; The longitudinal length of each movable mold skeleton of the middle segment is less than the longitudinal length of the panel, and the length difference between the connected end skeletons of the middle segment and the panel is not less than the maximum interference within the thickness range of the movable mold skeleton corresponding to the middle segment during the mold closing process of each movable mold of the variable segment; The longitudinal length of each movable mold skeleton of the end segment is less than the longitudinal length of the panel, and the length difference between the end skeletons and the panel of the variable segment is not less than the maximum interference amount within the thickness range of the movable mold skeleton corresponding to the end segment during the mold closing process of each movable mold of the variable segment; When closing the mold, the variable segment is closed first. After the movable mold of the variable segment is shrunk into place, the outer contour of the part extending into the space of the middle segment is smaller than the inner contour formed by the first movable mold panel after the middle segment is closed into place, and the outer contour of the part extending into the space of the end segment is smaller than the inner contour formed by the first movable mold panel after the movable mold of the end segment is shrunk into place.

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