Ginged folding hatchcover is generally composed of two cover plates, called a single pair of folding. The active cover plate near the end of the hatch has a pair of hinge arms extending out of the hatch, through which the hinge arm and the end hinge connect the cover plate with the deck. A roller is arranged on both sides of the driven cover plate end. During opening, the active cover rotates around the end hinge shaft and pulls the roller of the driven cover onto the track until the two cover plates are folded together and stored outside the hatch end above the panel of the hatch coiling plate. A foldable hatch cover consisting of two or more pairs of cover plates is called a multi-pair foldable hatch cover, which is connected between each pair of cover plates with a drag eye plate and folded one by one when opened
Folding Hatchcover Type The folding hatchcover device is similar to the rolling hatchcover device, except that each cover plate is hinged. Folding hatches can be divided into hydraulic drive type (with hydraulic pressure), direct pull type (with crane or boom), cable towed type (with winch). Hydraulically driven folding hatchcover The two-page hydraulic hinged hatchcover switch process is relatively simple. When opened, the cylinder plunger extends to raise the hinge point, and the two cover plates are raised at the same time until folded. The cover plate near the hatch end is shorter, because it is connected with the hinged arm, so its rotating shaft should maintain a certain distance from the hatch end.
The four-page hydraulic hinged hatchcover switch process is as follows: (1) Start the process. The second set of cover plates (No.3+No.4) begins to lift while dragging the first set of cover plates (No.1+No.2). The lifting of the second group of cover plates ends, and the lifting of the first group of cover plates begins until all are opened. When the hatchcover is opened to the storage position, the collection hook automatically falls, gripping the hatchcover and making it fixed. (2) Closing process. After the first group of cover plate slides down, the second group of cover plate starts to slide down and pushes the first group of cover plate at the same time, the second group of cover plate slides down and all are closed. In the collection position, the Angle between the two cover plates should be appropriate, so that the cover plate is easy to slide down without tipping.
Direct pull folding hatchcover The direct pull folding hatchcover consists of three hinged panels. It uses the ship's lifting machinery to store the cover plate at the end of the hatch. The cable passes through a block hinged to the end plate and is connected to the middle cover plate. The cable is tightened or loosened to open or close the hatch cover. The hinged block and the drag eye plate are arranged at the midpoint of the width of the cover plate, and the remaining members are installed in pairs on both sides of the cover plate. The direct pull hatchcover is easy to use the automatic compression device, so that the operation of the compression and the process of closing the hatchway are carried out at the same time, so the operation is simpler than the roll type, and the price is cheaper than the hydraulic folding type, but the need for the ship's boom (or crane).
Cable-towed collapsible hatch cover In the process of operation, the corresponding component action of the cable-towed folding hatchcover is basically the same as that of the hydraulic folding hatchcover, but due to the complexity of wearing the cable guide (especially when multiple cover plates are folded), the time required to switch the cabin is longer and the labor intensity is greater. Whether it is a rolling or folding hatchcover, the compression device should be released before opening, and the roller and guide device should be checked. When it is confirmed that there are no obstacles, the safe operation procedures and steps for opening the hatchcover should be followed. After opening the hatchcover, the fixed hook or cable should be fixed in the storage space to prevent sliding. Similarly, when the hatch is closed, it should be checked that there are no obstacles around the guide plate and on the track, and then release the fixed hook or cable chain according to the safe operation procedures and steps of the hatch. The hatch cover on the open deck should also be tightened with the compactor to ensure that the hatch cover is watertight.
Characteristics and Application (1) Folding cover plate size, good strength, fewer accessories, not easy to damage, suitable for loading a variety of deck cargo. Moreover, the transverse joint does not need a compager, the roller does not need a jacking device, the opening and closing operation is simple and reliable, and the collection length and height are adaptable, which is suitable for both open deck and middle deck. Therefore, it is widely used in general dry cargo ships, multi-purpose ships, refrigerated ships, wood carriers and small and medium-sized bulk carriers.
(2) The cover plate is divided according to the length of the hatch and the collection status, and the number of cover plates and the collection direction are determined. Single pair folding is preferred. For hatches with sufficient collection status at only one end or longer hatches, and the number of cover blocks is large, multiple pairs of folding can be used. The multi-pair folding mechanism is complex, the reliability is not as good as the single-pair folding type, and the maintenance is not convenient, so the collapsible cover plate collected towards one end of the cable operation should not exceed two pairs; No more than 3 pairs of folding cover plates are collected towards one end of the cylinder drive. On open decks, 3-pair folding is rarely used.
(3) If the hatchcover is opened to both ends, if there is no loading requirement for partial opening, the separation joint is generally located in the middle of the hatchway length, and the cover plate is arranged symmetrically at the end and end.
(4) When containers are loaded above and below the hatch of a multi-purpose ship, in order to meet the requirements of partial opening, the position of the separation joint should be determined according to the position of the container above and below the hatch cover. For a cargo hatch with 3 rows of 20-foot containers (or a row of 20-foot containers and a row of 40-foot containers) arranged longitudinally (with a net opening length of approximately 19.2m), the hatch cover separation joint shall not be located in the middle of the hatch length, but between the 20-foot and 40-foot containers.
Driving Mode The folding hatchcover is mainly opened and closed by hydraulic cylinder, which can be divided into external and built-in according to its installation position. External hydraulic cylinder is widely used because of its advantages such as simple installation, reliable performance and easy maintenance. A hydraulic cylinder is usually arranged at the end of the active cover plate of the first pair of cover plates. In the side part of the active cover plate of the second pair of cover plate, the lifting arm and lifting wheel are arranged, and the operation is carried out through the hydraulic cylinder located under the lifting arm. The built-in cylinder is to arrange the hydraulic cylinder in the cover plate structure, which is less used.
