A rear-opening door device for a freight container

Abstract

A rear-opening door device for a freight container, belonging to the field of transportation vehicles, is installed on the container body, located at the rear end of the container body, and connected to the container body. It includes a cylinder seat pin, a cylinder seat, a lower end of a wire rope, a lower seat of the wire rope, a steering guide wheel seat, a steering guide wheel, a hydraulic cylinder, a piston rod, a pulley seat, a pulley shaft, a pulley, a mounting box, a wire rope, an upper end of the wire rope, an upper seat of the wire rope, a cylinder fixing seat, and a mounting box cover. It features high working efficiency, simple structure, reasonable force distribution, and reduced dust pollution.

Description

Technical Field

[0001] This invention belongs to the field of transportation vehicles, and specifically relates to a rear-opening door device for a freight container used for bulk cargo transportation and having a rear self-unloading function. Background Technology

[0002] Freight containers are a commonly used, intensive means of transporting goods in the freight industry. They are characterized by good enclosure, flexibility, ease of loading and unloading, and relatively enclosed loading areas, leading to their widespread application in transportation sectors including land, sea, air, and rail. During freight container transport, especially in bulk cargo transport, loading is largely automated using loading equipment. However, unloading hinders the improvement of container transport efficiency. Therefore, freight containers with self-unloading capabilities have been developed. Existing self-unloading freight containers are generally divided into two types: side-unloading and rear-unloading. Side-unloading containers offer faster unloading speeds and shorter lifting distances. While self-unloading containers offer advantages such as not affecting vehicle movement after unloading and concentrated unloading, their close proximity to the vehicle body can easily disrupt the vehicle's continued movement. Rear-tilting containers, on the other hand, allow unloading without affecting vehicle movement and offer concentrated unloading, but when the container is long, the lifting height is excessive, causing instability and safety hazards during unloading. Furthermore, to regulate the consistency and safety of freight vehicles, the state has issued a series of standards for freight vehicles and freight containers; vehicles that do not meet national regulations are prohibited from being used on roads or for transportation work. This places higher demands on the functionality of self-unloading freight containers. For example, regarding rear-tilting containers, to ensure road transport safety, regulations stipulate that after the container is placed on the skeleton vehicle, its... The rear end is not allowed to extend beyond the frame of the skeleton vehicle to prevent the safety of the following vehicle's occupants in the event of a rear-end collision. Regulations also stipulate that containers can only be placed on the skeleton vehicle; fixed connections between the container and the skeleton vehicle are not permitted to prevent unauthorized vehicle modifications. However, in practical applications, to prevent the container from being lifted too high during rearward unloading, its placement position is moved rearward. This brings the fulcrum closer to the center of the container during rearward tilting, reducing the lifting height and facilitating unloading. Furthermore, because the rear door of the container is a certain distance from the rear of the skeleton vehicle during rearward lifting, it prevents unloaded goods from piling up near the wheels and causing congestion. However, this structure is not permitted by national standards, which complicates the realization of the self-unloading function of freight containers. This adds to the difficulty; in addition, after the self-unloading function is added, the rear door needs to be opened manually each time the cargo is unloaded, which increases the labor intensity of the operators and also poses corresponding dangers. For this reason, the applicant has previously applied for a Chinese patent (a rear door opening and closing device for a rear self-unloading freight container, application number: 2025214124624), which realizes the automatic opening and closing of the rear door of the self-unloading container, which greatly facilitates the transportation of bulk cargo; however, in practical application, it was found that the rear door opening and closing device of the prior application is exposed outside the container body, and the moving element pulls the steel wire rope with lateral force. When the angle between the force direction of the steel wire rope and the lower opening pivot of the rear door is too small, it is difficult to close the rear door. The force on the lower part of the rear door is unreasonable, causing movement stagnation.Meanwhile, due to the limited working conditions of cargo containers, the components of the rear door opening and closing device, especially the moving parts, are easily contaminated or covered with dirt, causing damage to the components or obstruction of movement, thus reducing the reliability of the rear door opening and closing device. To address this deficiency, the applicant, based on a prior Chinese patent application (application number: 2025214124624), made improvements and applied for another Chinese patent (application number: 2025221236662), and conducted operation and testing on existing cargo containers. The results showed that the patent has the problem of unreasonable wire rope stress, increasing the stroke of the hydraulic cylinder, and causing lateral force on the piston rod of the hydraulic cylinder during force application, resulting in misalignment of the piston rod within the cylinder, causing severe localized wear, and increasing the workload of the hydraulic cylinder. Summary of the Invention

[0003] In response to the aforementioned problems in the earlier Chinese patent application (application number: 2025221236662), this invention proposes a rear-opening door device for a freight container that overcomes the deficiencies of existing freight containers with rearward self-unloading functions and the two aforementioned earlier Chinese patent applications. Specifically, the technical solution is a rear-opening door device for a freight container, characterized in that: the rear-opening door device is installed on the container body, located at the rear end of the container body, and connected to the container body, including a cylinder seat pin, a cylinder seat, a lower end of a wire rope, a lower seat of the wire rope, a steering guide wheel seat, a steering guide wheel, a hydraulic cylinder, a piston rod, a pulley seat, a pulley shaft, a pulley, a mounting box, and a steel... The system comprises a wire rope, an upper end of the wire rope, an upper seat for the wire rope, a cylinder mounting base, and a mounting box cover. The cylinder seat pin is mounted on the cylinder seat, hinged to the hydraulic cylinder. The cylinder seat is installed inside the mounting box and connected to it. The lower end of the wire rope is installed at the lower end of the wire rope, connected to it, and connected to the lower seat. The lower seat is installed on the lower opening door of the rear door of the housing and connected to it; when the wire rope moves, it can drive the lower opening door to move. The steering guide wheel seat is installed on the mounting box and connected to it. The steering guide wheel is installed on the steering guide wheel seat, connected to it via an axle, and can move within the steering guide wheel seat. The hydraulic cylinder rotates upwards; it is installed in the mounting box, with its bottom connected to the cylinder seat and its side connected to the cylinder fixing seat. The hydraulic circuit is connected to the hydraulic system of the lifting system. The piston rod is the piston rod of the hydraulic cylinder, installed inside the cylinder body, and extends upwards from one end of the cylinder body. A pulley seat is installed at one end of the piston rod and connected to it. The pulley shaft is installed on the pulley seat, connected to it, and can connect the pulley and the pulley seat to each other. The pulley is installed on the pulley shaft and connected to the pulley seat through the pulley shaft. The mounting box is installed on the housing, is a thin-walled, open cavity, and is fixedly connected to the housing. The wire rope is installed on the upper end of the mounting box. Between the lower end and the upper end of the wire rope, both ends are fixedly connected to the upper end and the lower end of the wire rope, respectively; the middle part of the wire rope should pass over the pulley and the steering guide wheel; the wire rope is a flexible rope; the upper end of the wire rope is installed on the upper end of the wire rope and fixedly connected to the upper end of the wire rope; the upper end of the wire rope is also connected to the upper seat of the wire rope, which can limit the range of motion of the upper end of the wire rope; the hydraulic cylinder fixing seat is installed in the mounting box, one end is connected to the mounting box, and the other end is connected to the hydraulic cylinder, which can relatively fix the position of the hydraulic cylinder in the mounting box; the mounting box cover is installed at the opening of the mounting box, connected to the mounting box, and can cover and close the opening of the mounting box.

[0004] Furthermore, the pulley has a groove on its outer circumference, the depth of which matches the diameter of the wire rope.

[0005] Furthermore, the mounting box is installed in an embedded manner on the housing.

[0006] Furthermore, the upper seat of the wire rope and the fixed seat of the hydraulic cylinder are an integral structure.

[0007] Furthermore, there is one or more cylinder mounting bases.

[0008] Beneficial effects The beneficial effects of this invention are that it enables the hydraulic cylinder to be driven with uniform force, shortens the driving stroke of the piston rod when opening the door, improves work efficiency, and has a simple structure and is easy to use. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the installation structure of the present invention on a freight container. Figure 2 This is a structural schematic diagram of one embodiment of the present invention. 1. Box body, 2. Lifting system, 3. Skeleton vehicle, 4. Rear door opening device, 5. Bottom door, 6. Top door, 41. Cylinder seat pin, 42. Cylinder seat, 43. Lower end of wire rope, 44. Lower seat of wire rope, 45. Steering guide wheel seat, 46. Steering guide wheel, 47. Hydraulic cylinder, 48. Piston rod, 49. Pulley seat, 410. Pulley shaft, 411. Pulley, 412. Mounting box, 413. Wire rope, 414. Upper end of wire rope, 415. Upper seat of wire rope, 416. Cylinder fixing seat, 417. Mounting box cover. Detailed Implementation

[0010] To better illustrate the technical solution of the present invention, specific embodiments of the present invention will now be described in conjunction with the accompanying drawings, such as... Figure 1 , Figure 2In this example, the same housing 1, lifting system 2, and frame vehicle 3 as those in the earlier Chinese patent application (application number: 2025221236662, hereinafter referred to as the earlier application) are selected. The housing assembly is installed according to the method of the earlier application, and a hole for the mounting box 412 is made at the rear of the housing 1 near the rear door frame. The shape and size of the mounting box match those of the mounting box 412. In this example, a commercially available cylindrical pin with a retaining ring is selected as the cylinder seat pin 41, and a commercially available cylinder tailstock is selected as the cylinder seat 42. The cylinder seat 42 is installed at the bottom of the mounting box 412 and fixedly connected to the bottom. The cylinder seat pin 41 is installed in the hole of the cylinder seat 42 and connected together with the tail of the hydraulic cylinder 47, and fixed to ensure that the hydraulic cylinder 47 can operate in oil... The cylinder seat 42 swings; bolts or screws can also be used instead of cylinder seat pin 41; in this example, a stepped cylindrical pin is selected as the lower end 43 and upper end 414 of the wire rope; the two ends of the wire rope 413 are fixedly connected using industry-standard methods (e.g., welding, screw fastening, bonding, etc. after the wire rope is installed); when connecting, ensure that the steps of the upper end 414 and the lower end 43 of the wire rope are located at the far end of the wire rope 413 and on the lower seat 44 and upper seat 415 of the wire rope, which can prevent the wire rope 413 from detaching from the lower seat 44 and upper seat 415 of the wire rope; in this example, steel plates or angle steel commonly used in the industry are selected as the lower seat 44 and upper seat 415 of the wire rope; the upper seat 415 of the wire rope is fixedly installed on the installation... On one side of the inside of box 412, corresponding to hydraulic cylinder 47, in this example, the upper steel wire rope seat 415 and the cylinder fixing seat 416 are combined into one unit, which simplifies the structure and saves costs. When the installation position is not suitable, this combined method is not suitable, and they are installed separately on the inside of the mounting box 412. The lower steel wire rope seat 44 is installed on the lower opening door 5 of the rear door and fixedly connected to the lower opening door 5. If necessary, a structure for installing the lower end 43 of the steel wire rope can be set on the lower opening door 5 to replace the lower steel wire rope seat 44, thus omitting the lower steel wire rope seat 44. A commercially available pulley with a grooved outer circumference, a matching pulley shaft, and a pulley seat are selected, and the pulley seat is selected to be compatible with the piston rod 4 of the hydraulic cylinder 47 in this example. The end structures are matched to ensure that the pulley seat can be connected and fixed to the piston rod 48. The radius and depth of the groove on the outer circumference of the pulley are selected according to the diameter of the wire rope 413. The aforementioned pulley, pulley shaft, and pulley seat are respectively used as pulley 411, pulley seat 49, and pulley shaft 410 in this example. After being combined according to the common method in this industry, they are installed at the end of the piston rod 48. In this example, the direction of the piston rod 48 is selected to be vertically upward. Similarly, in this example, commercially available pulley assemblies with grooves on the outer circumference of the pulley with a fixed base are selected as steering guide wheel 46, steering guide wheel seat 45, and steering guide wheel shaft, respectively. The number of steering guide wheels 46 and steering guide wheel seats 45 are selected according to the length of the wire rope 413 and the number of turns.The component is fixedly installed at the bend in the path traversed by the wire rope 413, and the wire rope 413 is fitted into the outer circumferential groove of the steering guide wheel 46 to prevent the wire rope 413 from coming out of the groove. A double-acting hydraulic cylinder commonly used in this industry is selected as the hydraulic cylinder 47. The bottom of the hydraulic cylinder 47 is hinged to the cylinder seat, the middle part of the hydraulic cylinder 47 is fixedly connected to the cylinder fixing seat 416, and the piston rod 48 of the hydraulic cylinder 47 is connected to the pulley seat assembly. A commercially available multi-strand wire rope commonly used in this industry is selected as the wire rope 413 in this example. The two ends of the wire rope 413 are fixedly connected to the upper end 414 and the lower end 43 of the wire rope, respectively, and the middle part passes around the pulley 411 and the steering guide wheel 46. This completes the implementation of the rear door opening device 4.

[0011] In this application, two rear-opening door devices 4 are selected and installed symmetrically on both sides of the rear of the container 1. When the cargo container arrives at the unloading point, the operator activates the rear-opening door device 4. The piston rod 48 of the hydraulic cylinder 47 moves downward, releasing the wire rope 413. Under the action of the weight of the cargo inside the container 1 and the weight of the lower opening door 5 itself, the lower opening door 5 gradually opens. Since the upper opening door 6 is a suspended door, it can automatically open under the push of the cargo and without the obstruction of the lower opening door 5. The lower opening door 5 stops when it is opened to an approximately horizontal position. In this way, the lower opening door 5 can act as a lifting plate to hold the unloaded cargo. Goods do not pile up near the wheels; the operator starts the lifting system 2, lifts the front end of the box 1 upwards, and the bulk goods gradually slide out from the rear door to achieve automatic unloading; after the bulk goods are unloaded, the operation is reversed to achieve automatic closing of the rear door; since in this example, the piston rod 48 of the hydraulic cylinder 47 is used to lift the middle of the wire rope 413 through the pulley 411, the wire rope 413 rises by 2 millimeters (approximate value) for every centimeter the piston rod 48 moves up, saving the stroke of the piston rod 48 and improving work efficiency. The force applied by the wire rope 413 is symmetrical on both sides of the piston rod 48, so there will be no problem of uneven force.

Claims

1. A rear-opening door device for a freight container, characterized in that: The rear door opening device is installed on the housing, located at the rear end of the housing, and connected to the housing. It includes a cylinder seat pin, a cylinder seat, a lower end of the wire rope, a lower wire rope seat, a steering guide wheel seat, a steering guide wheel, a hydraulic cylinder, a piston rod, a pulley seat, a pulley shaft, a pulley, a mounting box, a wire rope, an upper end of the wire rope, an upper wire rope seat, a cylinder fixing seat, and a mounting box cover. The cylinder seat pin is installed on the cylinder seat and hinges the cylinder seat to the hydraulic cylinder. The cylinder seat is installed inside the mounting box and connected to the mounting box. The lower end of the wire rope is installed at the lower end of the wire rope and connects to the lower end of the wire rope. The lower end is connected to and connected to the lower seat of the wire rope; the lower seat of the wire rope is installed on the lower opening door of the rear door of the box and connected to the lower opening door, so that the lower opening door can be driven to move when the wire rope moves; the steering guide wheel seat is installed on the mounting box and connected to the mounting box; the steering guide wheel is installed on the steering guide wheel seat, connected to the steering guide wheel seat through the wheel axle and can rotate on the steering guide wheel seat; the hydraulic cylinder is installed in the mounting box, with its bottom connected to the cylinder seat and its side connected to the cylinder fixing seat, and the hydraulic oil circuit connected to the hydraulic system of the lifting system; the piston rod is a hydraulic cylinder. A piston rod is installed inside the cylinder of a hydraulic cylinder and extends upwards from one end of the cylinder body. A pulley seat is installed at one end of the piston rod and connected to it. A pulley shaft is installed on the pulley seat, connected to it, and capable of connecting the pulley and the pulley seat to each other. The pulley is installed on the pulley shaft and connected to the pulley seat via the pulley shaft. The mounting box is installed on the housing and is a thin-walled, open cavity, fixedly connected to the housing. A steel wire rope is installed between the upper and lower ends of the piston rod, with both ends fixedly connected to the upper and lower ends of the steel wire rope, respectively. The middle section of the wire rope should pass over a pulley and a steering guide wheel; the wire rope is a flexible rope; the upper end of the wire rope is mounted on the upper end of the wire rope and fixedly connected to the upper end of the wire rope; the upper end of the wire rope is also connected to a wire rope upper seat, which can limit the range of motion of the upper end of the wire rope; the hydraulic cylinder fixing seat is installed in the mounting box, with one end connected to the mounting box and the other end connected to the hydraulic cylinder, which can relatively fix the position of the hydraulic cylinder in the mounting box; the mounting box cover is installed at the opening of the mounting box, connected to the mounting box, and can cover and close the opening of the mounting box.

2. The rear-opening door device for a freight container according to claim 1, characterized in that: The pulley has a groove on its outer circumference, and the depth of the groove matches the diameter of the wire rope.

3. The rear-opening door device for a freight container according to claim 1, characterized in that: The mounting box is installed in an embedded manner on the housing.

4. The rear-opening door device for a freight container according to claim 1, characterized in that: The steel wire rope seat and the hydraulic cylinder fixing seat are an integral structure.

5. The rear-opening door device for a freight container according to claim 1, characterized in that: There is one or more cylinder mounting bases.

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