Auxiliary device for coal collecting in self-unloading car

Abstract

The application discloses a kind of auxiliary devices of self-unloading car bottom coal collection, belong to coal sampling technical field.The device includes with the backstop of car hopper matching backstop, symmetrically being equipped with the tensioning device of backstop both sides, being equipped with the fixing device of bottom and being equipped with the pre-tightening device of backstop back face.Tensioning device is hung in car hopper side wall card slot by adjustable pull rod and hook claw;Bottom fixing device is connected by fixing piece and car hopper chassis crossbeam;Pre-tightening device provides adjustable pre-tightening force to backstop middle part by screw rod force mechanism.The application constructs a three-dimensional force self-balancing system by the specific synergistic combination of three fixing modes of two sides tensioning, bottom fixing and middle pre-tightening, can effectively resist the huge impact of coal flow when self-unloading car unloads coal, and firmly intercepts bottom coal sample.The device is convenient to install and disassemble, solves the technical problem that traditional automatic sampling machine cannot collect bottom coal sample with composition difference, and guarantees the representativeness and accuracy of coal quality inspection.

Description

Technical Field

[0001] This utility model belongs to the field of coal extraction technology, specifically relating to an auxiliary device for collecting coal from the bottom of a dump truck. Background Technology

[0002] Currently, thermal power plants commonly use automatic sampling machines to collect coal samples from the dump truck beds when inspecting incoming coal. However, to protect the dump truck bed floor from mechanical damage, the sampling head of the machine typically stops descending and begins sampling at a certain height, such as 10-20 cm, from the bottom of the bed. This results in the "bottom coal," which is right next to the bottom of the bed, not being collected into the sample. Due to particle size segregation and moisture settling during coal transportation, the composition of the bottom coal, such as ash content, moisture, and calorific value, may differ significantly from the upper coal sample. Long-term neglect of bottom coal samples means that the test results cannot accurately reflect the average quality of the entire truckload of coal, thus affecting the accuracy and economy of coal blending in power plants. Although there is a method of manually scraping residual coal from the bottom of the dump truck bed after unloading, this method is inefficient, has poor sample representativeness, and poses safety hazards.

[0003] In existing technologies, to solve similar temporary fixing problems, a step-by-step, independent fixing method is usually adopted. For example, some solutions use side hook structures, some use bottom bolt connections, and some use back support rods to prevent bending. However, under the specific dynamic and high-impact conditions of dump trucks unloading coal at an angle, these single or simple parallel fixing methods reveal obvious defects: step-by-step installation is time-consuming and labor-intensive, making it difficult to ensure uniform preload at each point; under the impact of coal flow, uneven stress at each fixing point can easily lead to local failure and thus overall instability; and the installation efficiency is low, failing to meet the operational requirements of batch and rapid coal sampling in thermal power plants. Therefore, there is an urgent need in this field for a dedicated device that can simultaneously achieve rapid installation, uniform stress distribution, and reliable overall fixing. Utility Model Content

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide an auxiliary device for collecting coal from the bottom of a dump truck.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] An auxiliary device for collecting coal from the bottom of a dump truck includes a baffle, a tensioning device, a bottom fixing device, and a pre-tensioning device;

[0007] The width of the baffle is matched with the width of the rear baffle of the dump truck bed;

[0008] The tensioning device consists of two sets, symmetrically arranged on the left and right sides of the baffle. Each set of tensioning devices includes a side baffle, a pull rod, a hook, and a locking element. The side baffle is fixedly connected to the end of the baffle and extends beyond the left and right side walls of the dump truck bed, with a horizontal fixing groove on its upper part. The rear end of the pull rod passes through the fixing groove and is locked on both sides of the side baffle by the locking element. The hook is fixed to the front end of the pull rod and is used to hook onto the pre-set slots on the side walls of the dump truck bed.

[0009] The bottom fixing device includes two fixing seats and a fixing component. The two fixing seats are symmetrically fixed on both sides of the bottom surface of the baffle and are used to be detachably connected to the bottom frame crossbeam of the dump truck bed through the fixing component.

[0010] The pre-tightening device includes a support frame, a thrust bearing, a lead screw, a force application handle, and a fastening seat located on the back of the baffle. The thrust bearing is mounted on the support frame. The lead screw passes through the thrust bearing, with its rear end connected to the force application handle and its front end having a threaded section. The fastening seat has an internal thread that mates with the threaded section, and is used to fix it to the rear of the dump truck bed, so that rotating the force application handle can drive the middle of the baffle to pre-tighten towards the inside of the truck bed.

[0011] Furthermore, the support frame consists of two reinforcing ribs arranged in an X-shape on the back of the baffle.

[0012] Furthermore, the front of the baffle has an inwardly concave structure.

[0013] Furthermore, the fastening seat is a block structure with mounting holes, which is fixed to the truck bed by welding or bolt connection.

[0014] The synergistic mechanism of the device of the present invention is as follows:

[0015] 1. Coordinated Force Transmission: The coal flow impact force (F) mainly acts on the central area of ​​the concave surface of the baffle 4. This force is decomposed into: a part is directly transmitted to the rear bottom plate of the truck bed through the reaction force (F1) formed by the central pre-tightening device; the other part, the moment that attempts to bend the baffle backward, is converted into the tension force (F2) on the tensioning devices on both sides and the shear force (F3) on the bottom fixing device.

[0016] 2. Mutually Reinforcing Relationship: The initial preload generated by the preload device causes the middle part of the baffle 4 to bulge slightly forward during the installation stage, establishing prestress within the structure. This prestress allows the tie rod 11 and the bottom bolt to directly bear the load without overcoming structural gaps when subjected to impact, significantly improving the system's response speed and stiffness. Conversely, the robust lateral and bottom constraints also provide a solid support for the middle preload, preventing instability.

[0017] 3. Collaborative Failure Protection: If any single fixed point becomes loose, its failure load will be immediately redistributed and borne by the other two fixed points, ensuring the overall system remains safe and providing valuable fault buffer time for operators. This inherent safety redundancy is not available in simple parallel structures.

[0018] Compared with the prior art, the beneficial effect of this utility model is that it provides a systematic and coordinated fixing solution, rather than a simple combination of components:

[0019] 1. Systematic Cooperative Fixing: This utility model, through the specific spatial layout and functional coupling of the two-sided tensioning devices, the bottom fixing device, and the central pre-tensioning device, forms a three-dimensional self-balancing force system. Under the impact of coal unloading, the central pre-tensioning force effectively counteracts the bending moment in the middle of the baffle, and the reduction of this moment directly reduces the load on the two-sided tie rods and the bottom fixing point. The three support each other and work together to evenly transfer the impact load to the solid parts of the truck bed, achieving an overall reinforcement effect.

[0020] 2. Rapid installation and high reliability combined: This invention enables operators to quickly complete installation through a standardized process of "initial positioning - locking both sides - fixing the bottom - final pre-tightening". More importantly, the final pre-tightening operation "activates" and "tunes" the entire fixing system, ensuring that all connection points are in the optimal stress state, thereby achieving dynamic reliability that cannot be achieved by a single fixing method while pursuing efficiency;

[0021] 3. Targeted problem solving: This utility model is specifically designed for the scenario of "bottom coal collection from dump trucks". Its overall structure and dimensions (such as baffle height, concave depth, and pull rod stroke) are determined based on in-depth research on coal flow impact force, bottom coal accumulation morphology, and truck hopper structure, and have strong scenario adaptability and problem-specificity.

[0022] 4. The front of the baffle of this utility model is designed with a concave structure, forming a pocket-shaped cavity, which can more effectively intercept and accommodate the sliding bottom coal, prevent the coal from overflowing from the sides and top of the baffle, and ensure sufficient sampling volume. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the installation structure of this utility model;

[0024] Figure 2 for Figure 1 A magnified schematic diagram of a portion of region A in the middle;

[0025] Figure 3 This is a schematic diagram of the structure of this utility model;

[0026] Figure 4This is a schematic diagram of the structure of this utility model from another perspective;

[0027] Figure 5 This is a schematic diagram of the rear structure of a dump truck bed;

[0028] In the diagram: 1-Dump truck; 2-Underframe crossbeam; 3-Slot; 4-Baffle; 5-Reinforcing rib; 6-Thrust bearing; 7-Force application handle; 8-Screw; 9-Side guard; 10-Fixing slot; 11-Pull rod; 12-Hook; 13-Locking component; 14-Fixing seat; 15-Fixing component; 16-Fastening seat. Detailed Implementation

[0029] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0030] like Figure 1-5 As shown, an auxiliary device for collecting coal from the bottom of a dump truck includes a baffle 4 that matches the width of the rear baffle of the dump truck 1, tensioning devices on both sides of the baffle 4, a bottom fixing device, and a pre-tightening device in the middle.

[0031] The baffle 4 is made of a Q345B low alloy structural steel plate that is 2.3 meters long, 0.4 meters high and 10 mm thick. Its front side is pressed into an arc-shaped groove structure with a depth of 150 mm by a plate rolling machine to enhance the interception capacity and structural strength.

[0032] The tensioning device includes side guards 9, pull rods 11, hooks 12, and locking components 13. The left and right ends of the baffle 4 are symmetrically welded with side guards 9, each 12mm thick, and the side guards 9 extend 150mm beyond the left and right baffles of the truck bed. The upper part of the side guards 9 is horizontally provided with a fixing groove 10. The pull rod 11 is a 20mm diameter 45# steel precision threaded rod, with its rear end passing through the fixing groove 10 and the two sides of the side guards 9 being fixedly connected by locking components 13 (nuts). The hooks 12 are fixed to the front end of the pull rod 11. The rear part of the side wall panels on both sides of the dump truck 1 is symmetrically provided with slots 3. The pull rod 11 extends forward so that the hooks 12 on both sides extend into the slots 3 on the side walls of the dump truck 1.

[0033] The bottom fixing device includes two fixing seats 14 and two fixing parts 15 (M16 high-strength fixing bolts). The two fixing seats 14 are symmetrically fixed on both sides of the bottom surface of the baffle 4 and correspond to the bottom frame crossbeam 2 of the dump truck 1. The fixing seats 14 are connected to the bottom frame crossbeam 2 by fixing bolts 15.

[0034] The pre-tightening device includes two support frames (reinforcing ribs 5), a thrust bearing 6, a force application handle 7, a lead screw 8, and a fastening seat 16. The two reinforcing ribs 5 are made of 50mm*50mm angle steel welded to the back of the baffle 4 in an X shape, and a thrust bearing 6 is fixed at the center of the intersection. The lead screw 8 passes through the middle of the thrust bearing 6, and its rear end is connected to the force application handle 7 (handwheel) by a key. Its front end is connected to the fastening seat 16, which is fixed in the center of the rear bottom plate inside the dump truck 1, by a thread.

[0035] To verify the effectiveness, reliability, and efficiency of this device, the following field tests were conducted:

[0036] 1. Test of bottom coal interception effect

[0037] Ten dump trucks carrying coal from the same batch were tested. Each truck was first sampled by an automatic sampler, and then the device was installed to unload the coal and collect the retained bottom coal. The total moisture, ash content, and calorific value were analyzed on the upper layer sample from the automatic sampler and the bottom coal sample retained by the device.

[0038] Results: The average total moisture content of the bottom coal samples was 2.1% higher and the average ash content was 3.5% higher than that of the upper coal samples. Based on this, the average calorific value calculated on the received basis was about 150 kcal / kg lower. The amount of coal retained was between 120-200 kg, which was sufficient to meet the needs of multiple samplings.

[0039] Conclusion: This device successfully retained bottom coal with significant compositional differences, solving the sampling blind zone problem of automatic samplers. The sample representativeness is good, and this also indirectly confirms the inherent reliability of this device under extreme operating conditions. Only when the device can withstand the coal unloading impact and stably retain sufficient bottom coal each time can statistically significant compositional difference data be continuously obtained.

[0040] 2. Fixed Reliability Testing

[0041] With the vehicle fully loaded, the impact of rapid coal unloading was simulated. Strain gauges were attached to the intersection of the reinforcing ribs at the key stress points of the baffle 4 and at the root of the tie rod to measure the stress changes during the coal unloading process.

[0042] Results: During the coal unloading impact phase, the maximum instantaneous strain borne by baffle 4 was approximately 35% of the material's yield strength. After coal unloading, all connections were inspected: there was no relative displacement between hook 12 and slot 3; the fixing bolts were not loose; and the handwheel of the pre-tightening device did not retract. The pre-tightening force decreased slightly after the impact but remained effective.

[0043] Conclusion: The above test data strongly demonstrates that the specific combination of "tightening on both sides + fixing at the bottom + pre-tightening in the middle" produces a significant stress dispersion and offsetting effect, efficiently channeling the impact force into the main structure of the vehicle body, rather than being rigidly borne by the baffle itself or a single connection point.

[0044] 3. Installation and disassembly efficiency test

[0045] The time required for skilled workers to complete the installation of the device from parking to positioning, as well as the time required to disassemble the device after sampling, were recorded. This was compared with the traditional method of manually cleaning residual coal from the bottom of the truck bed before resampling.

[0046] Results: The average installation time was 12 minutes, the average disassembly time was 8 minutes, and the total time was approximately 20 minutes. Traditional manual cleaning methods take an average of over 45 minutes and are labor-intensive and involve harsh environments.

[0047] Conclusion: The installation time advantage demonstrated by this device is not only due to the reduction in operation steps, but also because the integrated design avoids repeated adjustments and secondary tightening, as the pre-tightening force can automatically balance the state of each connection point.

[0048] 4. Durability test

[0049] The same device was repeatedly installed and used on more than 200 vehicles within three consecutive months.

[0050] Results: The main body of baffle 4 showed no visible plastic deformation, and the groove structure remained intact. The threaded portion of tie rod 11 showed normal wear, but this did not affect its function. There were no cracks at any of the weld points. The thrust bearing 6 continued to rotate freely.

[0051] Conclusion: This device is durable, has low maintenance costs, and can be reused for a long time.

[0052] In summary, this device can be safely, stably, and efficiently installed on dump trucks, effectively retaining a sufficient amount of bottom coal samples during the unloading process. Actual measurement data demonstrates that the composition of the retained bottom coal differs from that of the upper coal layer, overcoming the shortcomings of traditional sampling methods. The device is quick to install, easy to operate, highly reliable, and durable, fully achieving its design objectives and possessing significant practical value and potential for wider application.

[0053] The working process of this utility model:

[0054] 1. After the dump truck completes sampling using the standard automatic sampling machine, it drives into the designated area. The hydraulic lifting system is activated, and the truck bed is slowly raised to an angle of approximately 8° before stopping. At this point, a wedge-shaped gap approximately 10cm wide is created between the bottom of the rear tailgate and the floor of the truck bed.

[0055] 2. Two operators insert the baffle 4 of this auxiliary device into the gap from the rear of the truck bed. Initially align the position so that the front end of the lead screw 8 on the back of the baffle 4 is aligned and screwed into the fastening seat 16 inside the truck bed. Initially tighten the handwheel to put the baffle 4 into initial position.

[0056] 3. Loosen the locking pieces 13 at the rear ends of the pull rods 11 on both sides, pass the hook 12 through the fixing groove 10 on the side guard 9, and push the pull rod 11 forward so that the hook 12 accurately hooks into the slot 3 on the side wall of the truck bed. Then, tighten the locking pieces 13 on the inner and outer sides of the side guard 9 respectively to firmly lock the pull rod 11 in the current position of the fixing groove 10.

[0057] 4. Use a wrench to secure the fixing piece 15 of the bottom fixing seat 14 to the bottom frame crossbeam 2 of the truck bed.

[0058] 5. Finally, the operator rotates the force application handle 7 clockwise about 5-10 turns. Through the trapezoidal thread transmission, the lead screw 8 generates a forward pulling force. Through the thrust bearing 6 and the reinforcing rib 5, the preload is evenly transmitted to the middle of the entire baffle 4, causing it to produce a slight forward convex elastic deformation, thus completing the preload.

[0059] 6. Normal operation of the dump truck for lifting and unloading coal. After approximately 95% of the coal is successfully unloaded, a portion of the bottom coal is retained in the arc-shaped groove of baffle 4. Sampling personnel can safely and conveniently collect sufficient and representative bottom coal samples from this location.

[0060] 7. After sampling is complete, disassemble the device in reverse order. The whole process takes about 15 minutes.

Claims

1. An auxiliary device for collecting coal from the bottom of a dump truck, characterized in that: Includes baffle (4), tensioning device, bottom fixing device and pre-tensioning device; The width of the baffle (4) matches the width of the rear baffle of the dump truck (1); There are two sets of tensioning devices, symmetrically arranged on the left and right sides of the baffle (4); each set of tensioning devices includes a side baffle (9), a pull rod (11), a hook (12) and a locking element (13); the side baffle (9) is fixedly connected to the end of the baffle (4) and extends beyond the left and right side walls of the truck bed, and a horizontal fixing groove (10) is opened on its upper part; the rear end of the pull rod (11) passes through the fixing groove (10) and is locked on both sides of the side baffle (9) by the locking element (13); the hook (12) is fixed to the front end of the pull rod (11) and is used to hook onto the pre-set slot (3) on the side wall of the dump truck (1) of the truck bed. The bottom fixing device includes two fixing seats (14) and a fixing member (15). The two fixing seats (14) are symmetrically fixed on both sides of the bottom surface of the baffle (4) and are used to be detachably connected to the bottom frame beam (2) of the dump truck (1) through the fixing member (15). The pre-tightening device includes a support frame, a thrust bearing (6), a lead screw (8), a force application handle (7), and a fastening seat (16) located on the back of the baffle (4). The thrust bearing (6) is mounted on the support frame. The lead screw (8) passes through the thrust bearing (6), and its rear end is connected to the force application handle (7). The front end is provided with a threaded section. The fastening seat (16) is provided with an internal thread that mates with the threaded section. It is used to fix the fastening seat to the rear of the dump truck (1) so that when the force application handle (7) is rotated, it can drive the middle part of the baffle (4) to be pre-tightened into the truck bed.

2. The auxiliary device according to claim 1, characterized in that: The support frame consists of two reinforcing ribs (5) arranged in an X-shape on the back of the baffle (4).

3. The auxiliary device according to claim 1 or 2, characterized in that: The front of the baffle (4) has an inwardly concave structure.

4. The auxiliary device according to claim 1, characterized in that: The fastening seat (16) is a block structure with mounting holes, which is fixed to the truck bed by welding or bolt connection.

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