At present, in the tunnel machinery industry, the design scheme and internal structure of the lining trolley are different, but from the perspective of its use, the nature of the general road and railway trolleys is similar. The structure of the tunnel lining trolley consists of a portal frame assembly, a bracket assembly, a template assembly, an adjustment system, a hydraulic system, a running system, and an operating platform. Let’s take a closer look at it!
1.Door frame assembly
The gantry assembly is mainly composed of gantry beams, gantry columns, lower longitudinal beams, upper longitudinal beams, lower longitudinal beams, and gantry diagonal braces. Each part is connected by bolts to form the overall gantry, and each beam and column pass through The connecting beam is connected with the diagonal rod. The mast is supported on the traveling wheel frame, and the mast is bolted to the lower longitudinal beam. The bottom surface of the lower longitudinal beam is equipped with foundation jacks. When lining, the concrete load is transferred to the mast through the formwork and is respectively transmitted through the traveling wheels and the foundation jack. To the rails-the ground. Since the mast is the main load-bearing support structure of the trolley, general section steel cannot meet its strength and rigidity requirements, so it is necessary to use steel plate assembly welding to form box beam steel. At the same time, in order to ensure the strength, rigidity and stability of the entire mast, a mast diagonal brace is added between the upright column and the crossbeam. This not only ensures the stability of the column’s compression bar, but also enables the mast to have Sufficient stiffness. The mast diagonal bracing is roughly divided into four types: single diagonal brace, double diagonal brace, triangle diagonal brace and double beam diagonal brace. When making the trolley, choose the appropriate diagonal brace according to the mechanical requirements of the trolley and customer requirements.
2. Bracket assembly
The bracket is also called the upper frame, which mainly bears the weight of the concrete and formwork poured during the second lining. The lower part of the bracket transmits force through hydraulic cylinders and supporting jacks (for upper jacking design) or translation wheel mechanism (for lower jacking design) In the door frame part. The entire bracket and the template are connected to become a rigid force-bearing entity, which has different structural designs according to different projects and customer needs.
3. template assembly
The template assembly is mainly composed of left and right molds and left and right top molds. The bolts connect several top molds to the side molds. The connection between the top mold and the side molds is generally hinged, so that the side molds can be wound relative to the top mold. The rotation of the pin shaft achieves the adjustment of the trolley components and the demolding effect. When the mold is erected, the jacking hydraulic cylinder extends the top mold to the required height, and then operates the lateral hydraulic cylinder to adjust the side mold in place, and then adjusts the lateral screw jack and the ground jack to complete the mold erecting process. When demoulding, press the reverse operation on the side. The formwork is the working part that directly lining the tunnel concrete, and its appearance quality and external dimension accuracy directly determine the quality of the concrete lining. Therefore, our company pays special attention to the processing and production of the template part, and uses the assembled welding tire mold to ensure the accuracy of the overall shape and size, minimize the welding deformation, and ensure that the outer surface is smooth and free of defects such as unevenness. At the same time, in order to control the misalignment of adjacent templates, the stabilizing pin of interference fit is used to fix the arc plate as a body for processing, which has the problem of controlling misalignment.
4. the adjustment system
The adjustment system is mainly composed of a translation roller mechanism, a translation oil cylinder and a related hydraulic control system. The translation roller mechanism is supported on the cross beam of the mast, and the upper part is connected with the upper longitudinal beam. The upper longitudinal beam can be pushed by the extension and contraction of the translation hydraulic cylinder for translation adjustment to achieve the purpose of adjusting the vertical positioning and demolding of the template. The large adjustment amount of the translation cylinder is 100MM, and the working oil pressure is about 16MPA.
5. hydraulic system
The hydraulic system of the trolley consists of a hydraulic station, a hydraulic cylinder and a control oil circuit. The four jacking hydraulic cylinders are located at the four corners of the trolley. They can be lifted synchronously or adjusted by a single cylinder to complete the erection, demolding and demolding of the top mold. The top and bottom alignment of the template. The lateral oil cylinders are separately arranged on the left and right sides of the trolley, and the vertical mold of the side mold, demoulding and the left and right alignment of the template are completed by the expansion and contraction of the piston rod. There are two translational oil cylinders (four large trolleys), which are used to push the overall left and right movement of the formwork, so that the formwork can move left and right relative to the mast, so as to realize the alignment between the formwork center and the tunnel center. The trolley and hydraulic system use three-position four-way manual reversing valve to achieve expansion and contraction. The left and right hydraulic cylinders are each controlled by a reversing valve to synchronize the expansion and contraction on the same side; each of the 4 jacking hydraulic cylinders uses a reversing valve to control their actions, and the cylinders are locked by two-way hydraulic control check valves. To avoid the lowering of the trolley due to pressure relief, a one-way throttle valve is used to adjust the speed of the cylinder; the translational hydraulic cylinder can be operated with a reversing valve.
6. walking system
The walking system consists of two parts, active and passive, with a total of four sets of devices installed under the four-door frame. When the trolley travels, the power is provided by the front two sets of active walking mechanisms. The walking motor drives the reducer, and then the active walking mechanism is driven by the chain drive to drive the trolley to travel, and the rear two passive walking mechanisms follow. The walking system is generally equipped with a track clamp to ensure that the trolley will not automatically slide, especially in places with large slopes.
7. operating platform
The operating platform is the place where the staff operate and use the trolley and the equipment. It is divided into two working platforms at the front and rear, and the aisle between the two longitudinal sides of the trolley and the operating platform. The working platform is generally located on the mast, divided into upper and lower layers, and separated on the front and rear sides of the trolley in a wing shape. The hydraulic system control platform and the electrical control platform are installed on the working platform on the front side of the trolley. When operating the trolley, the commissioning personnel complete the trolley walking, debugging, mold erection, demoulding, etc. on the operating platform with a good plank or grid. When pouring concrete, the staff can observe the concrete pouring situation and the working condition of the trolley on the operating platform. Guardrails are arranged around the working platform to ensure the safety of the staff.