CN219908628U - Front support leg of folding bridge girder erection machine - Google Patents

Abstract

The utility model discloses a front support leg of a folding bridge girder erection machine, which comprises a rectangular support seat which is horizontally arranged, and a pair of longitudinal support legs which are vertically and fixedly connected to the left end and the right end of the top wall of the rectangular support seat, wherein each longitudinal support leg is formed by detachably connecting an upper support leg and a lower support leg which are coaxially arranged, and a folding mechanism for pulling the lower support leg to rotate upwards and a pulling mechanism for pulling and fixing the lower support leg are arranged at the connecting position of the upper support leg and the lower support leg. The utility model has the advantages that the upper supporting leg and the lower supporting leg which are detachably connected are matched with the folding mechanism arranged at the joint of the upper supporting leg and the lower supporting leg, so that the folding and folding of the lower supporting leg are easily realized, the bridge girder erection machine can conveniently pass through a tunnel, the transfer efficiency of the bridge girder erection machine is improved, the workload of disassembling the supporting leg and transferring the bridge girder erection machine and then assembling the bridge girder erection machine is reduced when the bridge girder erection machine passes through the tunnel, the bridge construction cost in the area where the bridge and the tunnel are connected is reduced, the construction period is shortened, and the potential safety hazard is reduced.

Description

Front support leg of folding bridge girder erection machine

Technical Field

The utility model relates to the technical field of bridge construction, in particular to a front support leg of a folding bridge girder erection machine.

Background

At present, because of more mountain areas in China, a plurality of bridge-tunnel connection conditions exist in bridge construction, and aiming at the conditions, a bridge girder erection machine needs to consider the problem of tunnel. Usually, in order to meet the requirement that the concrete beam body can pass through the bridge girder erection machine, the design of the supporting legs of the bridge girder erection machine is quite large, at the moment, when the whole bridge girder erection machine passes through a tunnel, the whole supporting legs are detached, then a truck is used for transporting, and after the bridge girder erection machine with the detached supporting legs passes through the tunnel, the supporting legs are reassembled on the bridge girder erection machine; because landing leg equipment operation needs to use the crane, and the tunnel portal department receives the place restriction and leads to the use of crane relatively difficult, consequently seriously influenced the transfer efficiency of bridge crane, greatly increased construction work load, construction cost and engineering time, still have more potential safety hazards simultaneously.

Disclosure of Invention

The utility model aims to provide a front support leg of a folding bridge girder erection machine.

In order to achieve the above purpose, the present utility model may adopt the following technical scheme:

the front support leg of the folding bridge girder erection machine comprises a rectangular support seat which is horizontally arranged, and a pair of longitudinal support legs which are vertically and fixedly connected to the left end and the right end of the top wall of the rectangular support seat, wherein each longitudinal support leg is formed by detachably connecting an upper support leg and a lower support leg which are coaxially arranged, and a folding mechanism for pulling the lower support leg to rotate upwards and a pulling mechanism for pulling and fixing the lower support leg are arranged at the connecting position of the upper support leg and the lower support leg.

The utility model has the advantages that the upper supporting leg and the lower supporting leg which are detachably connected are matched with the folding mechanism arranged at the joint of the upper supporting leg and the lower supporting leg, so that the folding and folding of the lower supporting leg are easily realized, the bridge girder erection machine can conveniently pass through a tunnel, the transfer efficiency of the bridge girder erection machine is improved, the workload of disassembling the supporting leg and transferring the bridge girder erection machine and then assembling the bridge girder erection machine is reduced when the bridge girder erection machine passes through the tunnel, the bridge construction cost in the area where the bridge and the tunnel are connected is reduced, the construction period is shortened, and the potential safety hazard is reduced.

Further, the upper leg and the lower leg are rectangular legs coaxially aligned; at this time, the lower ends of the lower supporting legs can be vertically and fixedly connected to the top wall of the rectangular support through connecting flanges; simultaneously, still can be in the lower extreme of last landing leg sets up the connection limit along circumference the upper end of lower landing leg along circumference set up with go up the lower connection limit that the connection limit is laminated mutually, go up the connection limit with the connection limit is through the connecting bolt spiro union that even interval was arranged links firmly as an organic wholely down to realize the detachable connection of last landing leg and lower landing leg.

Further, the folding mechanism comprises a main swivel mount fixed at the lower edge of the front wall of the upper supporting leg and an auxiliary swivel mount fixed at the upper edge of the front wall of the lower supporting leg and rotationally connected with the main swivel mount, and the rotation direction of the auxiliary swivel mount is the upward rotation folding direction of the lower supporting leg; in addition, the side wall of the upper supporting leg is hinged with a traction hydraulic rod which is consistent with the rotation direction of the lower supporting leg through an upper rotating shaft, and the telescopic end of the traction hydraulic rod is hinged on the side wall of the lower supporting leg through a lower rotating shaft, so that the lower supporting leg can be driven to turn upwards by taking the hinge shafts of the main rotating seat and the auxiliary rotating seat as the central shaft through the telescopic and adaptive rotation of the traction hydraulic rod, and the folding function of the lower supporting leg is realized.

Further, the pulling mechanism comprises a manual telescopic rod hinged to the front wall of the lower supporting leg, the manual telescopic rod is composed of an outer sleeve and an inner penetrating rod coaxially penetrating through the outer sleeve, a plurality of positioning holes are uniformly formed in the rod wall of the inner penetrating rod at intervals along the length direction, and a positioning pin which is adapted to be inserted into the positioning holes is vertically penetrated in the rod wall of the outer sleeve; in addition, a hinge joint with a connecting perforation is arranged at the telescopic end of the inner penetrating rod, a hinge seat matched with the hinge joint is arranged on the front wall of the upper supporting leg, and a hinge bolt with the same aperture as the connecting perforation is horizontally inserted on the hinge seat; after folding mechanism drives down landing leg upwards to rotate and fold in place, can connect articulated joint and articulated seat through articulated bolt, the length adjustment of cooperation manual telescopic link adaptability simultaneously realizes the pulling to lower landing leg, alleviates the atress of pulling the hydraulic stem among the folding mechanism, promotes the stability when folding receipts of landing leg down.

Further, for making the vertical support leg more firm, can be located two of rectangle support top lower support leg between horizontal crossbearer rectangular structure's reinforcement support column, reinforcement support column's lower surface both ends department articulates respectively has an oblique branch, two oblique branch's slope lower extreme articulates in the roof central point department of rectangle support to form a stable triangle-shaped bearing structure between two lower support legs, with the stability that promotes two lower support legs, and then promote the stability of two sets of vertical support legs.

Further, at least two groups of pushing mechanisms for pushing the lower ends of the lower support legs to rotate forwards are arranged on the rear side wall of the reinforcing support column at intervals along the length direction, each pushing mechanism comprises a guide cylinder with internal threads, an upper telescopic screw rod and a lower telescopic screw rod, the upper telescopic screw rods are arranged in the guide cylinders in a penetrating mode, the upper ends of the upper telescopic screw rods are hinged to the rear side wall of the reinforcing support column, fixing seats for supporting the lower support legs on the ground are hinged to the lower ends of the lower telescopic screw rods, vertical anchor rods for anchoring the lower support legs on the ground are arranged on the fixing seats in a penetrating mode, the vertical anchor rods can be threaded rods penetrating the fixing seats, the fixing seats can be supported on the ground through the vertical anchor rods, the upper telescopic screw rods and the lower telescopic screw rods extend outwards simultaneously through screwing the guide cylinders, and the lower support legs detached in a penetrating mode are rotated forwards for a certain distance, so that the lower support legs keep an inclined posture, and the folding mechanism can be pulled upwards to fold and retract.

Further, a plurality of groups of auxiliary jacking mechanisms for keeping the lower supporting leg and the upper supporting leg coaxially aligned are arranged on the front side of the rectangular support; the auxiliary jacking mechanism comprises a supporting hydraulic rod hinged to the front edge of the top wall of the rectangular support, the rotation direction of the supporting hydraulic rod is consistent with that of the lower supporting leg, a supporting anchor is hinged to the telescopic end of the supporting hydraulic rod, and anchor bolts penetrate through the supporting anchor; when the lower supporting leg is driven by the folding mechanism to rotate downwards to be in coaxial alignment with the upper supporting leg, the supporting hydraulic rod can be rotated to be in a vertical state, the supporting foot is firmly fixed on the ground, and then the supporting hydraulic rod is operated to enable the supporting foot to extend downwards vertically, so that the lower supporting leg is pushed upwards vertically, the upper end of the lower supporting leg can be firmly attached to the lower end of the upper supporting leg, and the upper supporting leg and the lower supporting leg are firmly connected together easily.

Further, in order to enhance the supporting strength of the rectangular supporting seat, a plurality of vertical reinforcing ribs can be uniformly distributed on the front side wall and the rear side wall of the rectangular supporting seat at intervals along the length direction.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is an exploded schematic view of fig. 1.

Fig. 3 is an enlarged view of the rectangular support of fig. 2.

Fig. 4 is an enlarged view of the manual telescopic link of fig. 2.

Fig. 5 is an enlarged view of the ejector mechanism of fig. 2.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

In the present utility model, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

As shown in fig. 1 and 2, the front support leg of the folding bridge girder erection machine provided by the utility model comprises a rectangular support 1 which is horizontally arranged, and a pair of longitudinal support legs which are vertically and fixedly connected to the left end and the right end of the top wall of the rectangular support 1, wherein each longitudinal support leg is formed by detachably connecting an upper support leg 2 and a lower support leg 3 which are coaxially arranged, and a folding mechanism which pulls the lower support leg 3 to rotate upwards and a pulling mechanism which pulls and fixes the lower support leg 3 are arranged at the connecting position of the upper support leg 2 and the lower support leg 3.

Specifically, the upper support leg 2 and the lower support leg 3 are rectangular support legs, and the cross sections of the upper support leg 2 and the lower support leg 3 are consistent in size; at this time, the upper ends of the upper supporting legs 2 should be vertically and fixedly connected to the bridge girder erection machine, while the lower ends of the lower supporting legs 3 are vertically and fixedly connected to the top wall of the rectangular support 1 through the connecting flange 4, so that the two groups of longitudinal supporting legs and the rectangular support 1 connected to the lower ends of the two longitudinal supporting legs together form the front supporting legs of the bridge girder erection machine. Of course, in order to realize the detachable connection of the upper leg 2 and the lower leg 3 forming the longitudinal leg, an upper connecting edge 5 should be circumferentially arranged at the lower end edge of the upper leg 2, a lower connecting edge 6 which can be fit with the upper connecting edge 5 is circumferentially arranged at the upper end edge of the lower leg 3, and through holes 7 which can be aligned one by one are uniformly distributed on the upper connecting edge 5 and the lower connecting edge 6 at intervals, so that when the upper connecting edge 5 and the lower connecting edge 6 are fit with each other, the upper connecting edge 5 and the lower connecting edge 6 can be fixedly connected together in a threaded manner through connecting bolts 8 which are fit on the through holes 7, and the upper leg 2 and the lower leg 3 are further connected into a whole.

The folding mechanism comprises a main swivel base 9 fixed at the lower edge of the front wall of the upper supporting leg 2 and an auxiliary swivel base 10 fixed at the upper edge of the front wall of the lower supporting leg 3 and rotationally connected with the main swivel base 9, at the moment, the connecting bolts 8 are all disassembled, so that the upper end face of the lower supporting leg 3 is separated from the lower end face of the upper supporting leg 2, the main swivel base 9 can serve as a fixed base, the auxiliary swivel base 10 is enabled to rotate upwards, the lower supporting leg 3 is driven to rotate upwards, and the rotating direction of the auxiliary swivel base 10 is the rotating, folding and folding direction of the lower supporting leg 3. In addition, folding mechanism still includes setting up on the upper leg 2 lateral wall with lower leg 3 rotation direction unanimous pull hydraulic stem 11, specifically, this pulls hydraulic stem 11 and is electronic hydraulic stem, pull hydraulic stem 11's upper end (i.e. stiff end) and hinge on upper leg 2's lateral wall through an upper pivot 12, pull hydraulic stem 11's lower extreme (i.e. flexible end) and hinge on lower leg 3's lateral wall through a pivot 13 promptly, thereby can drive lower leg 3 through pulling hydraulic stem 11's flexible and adaptive rotation, it upwards overturns to use the articulated shaft of main swivel mount 9 and vice swivel mount 10 as the dabber, realize lower leg 3's folding, make the bridge girder erection machine can pass through the tunnel.

The pulling mechanism comprises a manual telescopic rod 14 hinged on the front wall of the lower supporting leg 3, as shown in fig. 4, the manual telescopic rod 14 consists of an outer sleeve 14.1 and an inner penetrating rod 14.2 coaxially penetrating the outer sleeve, a plurality of positioning holes 15 are uniformly arranged on the rod wall of the inner penetrating rod 14.2 at intervals along the length direction, and a positioning pin 16 capable of being inserted into the positioning holes 15 is vertically penetrated on the rod wall of the outer sleeve 14.1; in addition, a hinge joint 18 with a connecting perforation 17 is further arranged on the telescopic end of the inner penetrating rod 14.2, a hinge seat 19 matched with the hinge joint 18 is further arranged on the front wall of the upper supporting leg 2, and a hinge bolt 20 with the same aperture as the connecting perforation 17 is horizontally inserted on the hinge seat 19, so that the hinge seat 19 and the hinge joint 18 can be hinged through the hinge bolt 20, and further the hinge between the hinge seat 19 and the telescopic end of the inner penetrating rod 14.2 is realized. After the lower supporting leg 3 is driven by the folding mechanism to rotate upwards and fold in place, the inner penetrating rod 14.2 can be manually pulled outwards, the hinge joint 18 at the telescopic end of the inner penetrating rod 14.2 is connected to the hinge seat 19 in an adapting and clamping mode, the positioning pin 16 is installed at the moment to fix the telescopic length of the inner penetrating rod 14.2, and meanwhile, the hinge pin 20 is installed to enable the hinge joint 18 to be connected with the hinge seat 19, so that the lower supporting leg 3 can be pulled and fixed, the stress of the traction hydraulic rod 11 in the folding mechanism is relieved, even the traction hydraulic rod 11 can be enabled to be not stressed any more, the traction hydraulic rod 11 does not need to continuously shrink to pull the lower supporting leg 3 at the moment, the stability of the folding and folding of the lower supporting leg 3 is improved, and the service life of the traction hydraulic rod 11 is prolonged.

In addition, in order to reduce the weight of the rectangular support 1, the rectangular support 1 may be designed as a hollow structure, and at this time, in order to enable the rectangular support 1 to be supported more stably, a plurality of vertical reinforcing ribs 21 (as shown in fig. 3) may be uniformly arranged on the front and rear sidewalls of the rectangular support 1 at intervals along the length direction, and the supporting strength of the rectangular support 1 is enhanced by the vertical reinforcing ribs 21. In order to make two sets of vertical support legs more stable when the support frame bridge machine, a reinforcing support column 22 with a rectangular structure can be horizontally arranged between two lower support legs 3 above the rectangular support seat 1, two inclined support rods 23 are respectively hinged at two ends of the lower surface of the reinforcing support column 22, and the inclined lower ends of the two inclined support rods 23 are hinged at the center position of the top wall of the rectangular support seat 1, so that a stable triangular support structure is formed between the two lower support legs 3 to improve the stability of the two lower support legs 3, and further improve the stability of the two sets of vertical support legs.

Further, when the upper leg 2 and the lower leg 3 are kept in coaxial alignment (i.e. in the state of the vertical leg supporting bridge girder erection machine), even if the joints of the upper leg 2 and the lower leg 3 are detached, the lower leg 3 cannot be pulled to turn upwards by the traction hydraulic rod 11 of the folding mechanism, so that at least two groups of pushing mechanisms for pushing the lower end of the lower leg 3 to turn forwards need to be arranged on the rear side wall of the reinforcing support column 22 at intervals along the length direction in order to ensure that the traction hydraulic rod 11 can pull the lower leg 3 to turn upwards for folding. Specifically, as shown in fig. 5, the pushing mechanism includes a guide cylinder 24 with internal threads, and an upper telescopic screw 25 and a lower telescopic screw 26 screwed in the guide cylinder 24, the upper telescopic screw 25 and the lower telescopic screw 26 are coaxial, the upper end of the upper telescopic screw 25 is hinged on the rear side wall of the reinforced support column 22, the lower end of the lower telescopic screw 26 is hinged with a fixing seat 27 for supporting and fixing on the ground, a vertical anchor rod 28 for anchoring on the ground is penetrated on the fixing seat 27, the vertical anchor rod 28 can be a threaded rod screwed on the fixing seat 27, the fixing seat 27 can be anchored on the ground through the vertical anchor rod 28, the guide cylinder 24 is further supported behind the lower support leg 3 in an inclined manner, at this time, the guide cylinder 24 is rotated to enable the upper telescopic screw 25 and the lower telescopic screw 26 to be outwards elongated, an inclined pushing force consistent with the axial direction of the guide cylinder 24 is further applied to the reinforced support column 22, the component in the vertical direction of the inclined pushing force is counteracted by the upper support leg 2, the lower support leg 3 can be rotated forwards by the horizontal component, the lower support leg 3 can be rotated forwards, the lower support leg 3 can be pulled upwards, the lower support leg 11 can be pulled upwards, and the lower support leg 11 can be pulled upwards to rotate together, and the lower support leg 11 can be pulled upwards, and rotated together. Of course, after the traction hydraulic rod 11 is opened to pull the lower supporting leg 3 upwards, the vertical anchor rod 28 is detached, so that the fixing seat 27 is not fixedly connected with the ground any more, the lower supporting leg 3 can be pulled and rotated upwards by the traction hydraulic rod 11, and the purpose of the pushing mechanism is to push the lower supporting leg 3 to keep an inclined posture, so that the traction hydraulic rod 11 can rotate for a certain angle, and the traction action of the traction hydraulic rod 11 can be realized.

Further, to ensure that the screwing and fixing of the upper leg 2 and the lower leg 3 can be easily completed when the lower leg 3 rotates downward to be aligned with the upper leg 2 coaxially, a plurality of groups of auxiliary jacking mechanisms for keeping the lower leg 3 and the upper leg 2 aligned coaxially may be provided on the front side of the rectangular support 1. Specifically, the auxiliary jacking mechanism comprises a supporting hydraulic rod 29 hinged to the front edge of the top wall of the rectangular support 1, the rotating direction of the supporting hydraulic rod 29 is consistent with that of the lower supporting leg 3, the supporting hydraulic rod is also longitudinally rotated, a supporting foot 30 is hinged to the telescopic end of the supporting hydraulic rod 29, and a foot bolt 31 is arranged on the supporting foot 30 in a penetrating manner; when the lower supporting leg 3 is driven by the folding mechanism to rotate downwards to be in coaxial alignment with the upper supporting leg 2, the supporting solid-liquid pressure rod 29 can be rotated to the vertical downward direction of the telescopic end, the supporting solid-liquid leg 30 is firmly fixed on the ground, and then the supporting solid-liquid pressure rod 29 is operated to enable the supporting solid-liquid leg to extend downwards vertically, so that the lower supporting leg 3 is pushed upwards, the upper end of the lower supporting leg 3 can be firmly attached to the lower end of the upper supporting leg 2, the upper supporting leg 2 and the lower supporting leg 3 can be firmly connected together easily, and the longitudinal supporting leg formed by the upper supporting leg 2 and the lower supporting leg 3 can be firmly supported again through a bridge girder erection machine after a tunnel.

Claims (10)

1. The utility model provides a stabilizer blade before folding bridge crane which characterized in that: the folding device comprises a rectangular support arranged horizontally and a pair of longitudinal support legs which are fixedly connected to the left end and the right end of the top wall of the rectangular support vertically, wherein each longitudinal support leg is formed by detachably connecting an upper support leg and a lower support leg which are coaxially arranged, and a folding mechanism for pulling the lower support leg to rotate upwards and a pulling mechanism for pulling and fixing the lower support leg are arranged at the joint of the upper support leg and the lower support leg.

2. The front foot of a folding bridge girder erection machine according to claim 1, wherein: the upper leg and the lower leg are rectangular legs coaxially aligned.

3. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: the lower end of the lower supporting leg is vertically and fixedly connected to the top wall of the rectangular support through a connecting flange.

4. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: the lower extreme of going up the landing leg is provided with along circumference and connects the limit the upper end of lower landing leg along circumference be provided with go up the lower connection limit that connects the limit looks laminating, go up the connection limit with connect the limit down and pass through the connecting bolt spiro union that even interval was arranged and link firmly as an organic whole.

5. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: the folding mechanism comprises a main swivel mount fixed at the lower edge of the front wall of the upper supporting leg and a secondary swivel mount fixed at the upper edge of the front wall of the lower supporting leg and rotationally connected with the main swivel mount; and the side wall of the upper supporting leg is hinged with a traction hydraulic rod which is consistent with the rotation direction of the lower supporting leg through an upper rotating shaft, and the telescopic end of the traction hydraulic rod is hinged on the side wall of the lower supporting leg through a lower rotating shaft.

6. The front foot of a folding bridge girder erection machine according to claim 5, wherein: the pulling mechanism comprises a manual telescopic rod hinged to the front wall of the lower supporting leg, the manual telescopic rod consists of an outer sleeve and an inner penetrating rod coaxially penetrating the outer sleeve, a plurality of positioning holes are uniformly formed in the rod wall of the inner penetrating rod at intervals along the length direction, and a positioning pin which is adapted to be inserted into the positioning holes is vertically penetrated in the rod wall of the outer sleeve; the telescopic end of the inner penetrating rod is provided with a hinge joint with a connecting perforation, the front wall of the upper supporting leg is provided with a hinge seat matched with the hinge joint, and the hinge seat is horizontally inserted with a hinge bolt with the same aperture as the connecting perforation.

7. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: the horizontal cross frame between the two lower supporting legs above the rectangular support is provided with a reinforcing supporting column with a rectangular structure, two ends of the lower surface of the reinforcing supporting column are respectively hinged with an inclined supporting rod, and the inclined lower ends of the two inclined supporting rods are hinged to the center position of the top wall of the rectangular support.

8. The front foot of a folding bridge girder erection machine according to claim 7, wherein: at least two groups of pushing mechanisms for pushing the lower ends of the lower supporting legs to rotate forwards are arranged on the rear side wall of the reinforcing supporting column at intervals along the length direction, each pushing mechanism comprises a guide cylinder with internal threads, an upper telescopic screw rod and a lower telescopic screw rod, the upper telescopic screw rods are arranged in the guide cylinders in a threaded mode in a penetrating mode, the upper ends of the upper telescopic screw rods are hinged to the rear side wall of the reinforcing supporting column, the lower ends of the lower telescopic screw rods are hinged to fixing seats used for being fixedly supported on the ground, and vertical anchor rods used for being anchored on the ground are arranged on the fixing seats in a penetrating mode.

9. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: a plurality of groups of auxiliary jacking mechanisms for keeping the lower supporting leg and the upper supporting leg coaxially aligned are arranged on the front side of the rectangular support; the auxiliary jacking mechanism comprises a supporting hydraulic rod hinged to the front edge of the top wall of the rectangular support, the rotation direction of the supporting hydraulic rod is consistent with that of the lower supporting leg, a supporting anchor is hinged to the telescopic end of the supporting hydraulic rod, and anchor bolts penetrate through the supporting anchor.

10. The front foot of a folding bridge girder erection machine according to claim 1 or 2, wherein: a plurality of vertical reinforcing ribs are uniformly distributed on the front side wall and the rear side wall of the rectangular support at intervals along the length direction.