A compression mechanism hydraulic system of a garbage collection vehicle and a working method thereof

Abstract

The application discloses a compression mechanism hydraulic system of a garbage collection vehicle and a working method thereof in the field of hydraulic systems, and comprises a push plate oil cylinder, a scraper oil cylinder and a sliding plate oil cylinder, and a compression valve block, a back pressure valve block and a plurality of reversing valves are arranged correspondingly to the push plate oil cylinder, the scraper oil cylinder and the sliding plate oil cylinder; a hydraulic oil tank supplies oil to the push plate oil cylinder, the scraper oil cylinder and the sliding plate oil cylinder through a double hydraulic pump, the reversing valves and the compression valve block and the back pressure valve block. The application can improve the garbage compression rate and the compression efficiency, protect the compression mechanism and facilitate personnel maintenance.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic systems, and specifically relates to a hydraulic system for the compression mechanism of a garbage collection vehicle and its working method. Background Technology

[0002] In the existing technology, as people pay more and more attention to environmental protection, there are more requirements for the collection, transportation and treatment of domestic waste. Various sanitation equipment have emerged. As a type of domestic waste collection and transportation vehicle, the rear-loading garbage collection truck is being used more and more widely. The rear-loading collection truck itself has the function of garbage collection and compression, which can ensure a certain garbage compression ratio, make full use of the garbage container, and prevent secondary pollution such as garbage falling or sewage leakage during transportation. It is the main equipment for the front-end collection of domestic waste in residential communities.

[0003] The main mechanism of a garbage collection truck is a garbage conveying and compression system composed of scrapers, sliding plates, and pusher mechanisms. The scraper mechanism collects the garbage, which is then moved into the container by the sliding plate mechanism. The pusher, together with the scraper and sliding plate, compresses the collected garbage. For the same container volume, a higher compression ratio allows for more garbage to be loaded at once, improving the container's volume utilization. The compression mechanism is primarily operated by hydraulic cylinders, controlled by a hydraulic control system. Many methods can achieve the compression function; most existing hydraulic control systems use a single pump drive, solenoid valve control, and position sensors to realize the entire action. Therefore, a good control system is crucial for ensuring smooth compression. Currently, the hydraulic control systems of garbage collection trucks exhibit low efficiency and reliability in the compression cycle when operating the scraper, sliding plate, and pusher mechanisms. Therefore, improving the efficiency and reliability of the compression cycle, a key indicator for evaluating a garbage collection truck, is an urgent problem to be solved. This solution proposes a method to address this issue. Summary of the Invention

[0004] One of the objectives of this invention is to provide a hydraulic system for the compression mechanism of a garbage collection vehicle, which can improve the garbage compression rate and efficiency, protect the compression mechanism, and facilitate personnel maintenance.

[0005] The objective of this invention is achieved as follows: a hydraulic system for the compression mechanism of a garbage collection vehicle includes a push plate cylinder, a scraper cylinder, and a sliding plate cylinder. A compression valve block, a back pressure valve block, and several directional valves are provided corresponding to the push plate cylinder, scraper cylinder, and sliding plate cylinder. The hydraulic oil tank supplies oil to the push plate cylinder, scraper cylinder, and sliding plate cylinder through a dual hydraulic pump, each directional valve, the compression valve block, and the back pressure valve block.

[0006] To facilitate the switching of the oil circuit, four directional valves are provided. The structure of directional valve one and directional valve four is the same. The middle position of directional valve one and directional valve four is respectively provided with oil ports A, B, P and T. The structure of directional valve two and directional valve three is the same. The middle position of directional valve two and directional valve three is respectively provided with oil ports A, B, P and T.

[0007] As a further improvement of the present invention, the dual hydraulic pump includes pump one and pump two. The hydraulic oil tank is connected to the inlets of pump one and pump two via two connecting pipes, respectively. The outlets of pump one and pump two are connected to the P ports of directional valve one and directional valve four via oil pipe one and oil pipe two, respectively. The T port of directional valve four is connected to one end of the return oil filter via oil pipe three, and the other end of the return oil filter is connected to the hydraulic oil tank. The T port of directional valve one is connected to the side of oil pipe three via oil pipe four. A connecting pipe one is provided between oil pipe four and the side of oil pipe one. An overflow valve is installed on the connecting pipeline 1. A connecting pipeline 2 is installed between the sides of oil pipeline 2 and oil pipeline 3. An overflow valve 2 is installed on the connecting pipeline 2. The P ports of both directional valve 3 and directional valve 2 are connected to the A port of directional valve 1. The T ports of both directional valve 3 and directional valve 2 are connected to the connection port of connecting pipeline 2 and oil pipeline 3. The compression valve block is provided with oil inlet ports A and B and oil outlet ports A1, B1, A21, B21, A22, and B22. Oil ports A and B of the compression valve block are respectively connected to the oil outlet of directional valve 4. Ports A and B are connected. Oil pipe A is connected to oil pipe five on the side of the connecting pipe between oil port A of the compression valve block and oil port A of the reversing valve four. The other end of oil pipe five is connected to oil port B of the reversing valve one. A check valve is installed on oil pipe five. Oil ports A1 and B1 of the compression valve block are connected to the rodless and rod chambers of the scraper cylinder, respectively. Oil ports A21 and B21 of the compression valve block are connected to the rod chamber and rodless chamber of the slide block cylinder via oil pipes six and seven, respectively. Oil ports A22 and B22 of the compression valve block are connected to the rod chamber and rodless chamber of another slide block cylinder, respectively. The oil port A of the reversing valve three is connected to the side of oil pipeline six, and the oil port B of the reversing valve three is connected to the side of oil pipeline seven via oil pipeline eight. The oil port A of the reversing valve two is connected to the rod chamber of the push plate cylinder, and the oil port B of the reversing valve two is connected to the rodless chamber of the push plate cylinder via oil pipeline nine. The back pressure valve block is provided with P, T and PIL oil ports respectively. The P oil port of the back pressure valve block is connected to the side of oil pipeline nine via oil pipeline ten, the T oil port of the back pressure valve block is connected to the hydraulic oil tank, and the hydraulic control oil port PIL of the back pressure valve block is connected to the side of oil pipeline eight.

[0008] As a further improvement of the present invention, two scraper cylinders are provided. The two scraper cylinders drive the scraper mechanism more smoothly.

[0009] As a further improvement of the present invention, the back pressure valve block is provided with a relief valve three, a back pressure valve one, and a hydraulic pilot valve. The inlet of the relief valve three is connected to the P port of the back pressure valve block, the outlet of the relief valve three is connected to the inlet of the back pressure valve one, the outlet of the back pressure valve one is connected to the T port of the back pressure valve block, the spring chamber of the relief valve three is connected to the inlet of the hydraulic pilot valve, the outlet of the hydraulic pilot valve is connected to the T port of the back pressure valve block, and the hydraulic flow channel of the hydraulic pilot valve is connected to the hydraulic port PIL of the back pressure valve block.

[0010] As a further improvement of the present invention, the side of the oil pipeline ten is connected to the inlet of safety valve one, the outlet of safety valve one is connected to the inlet of one-way throttle valve, the outlet of one-way throttle valve is connected to the hydraulic oil tank, the side of the connecting pipeline between the inlet of one-way throttle valve and the outlet of safety valve one is connected to the pressure transmitter, the connecting port of the side of oil pipeline ten and oil pipeline nine is also connected to the A oil port of unloading valve, and the B oil port of unloading valve is connected to the hydraulic oil tank.

[0011] As a further improvement of the present invention, the compression valve block is provided with several internal channels. The oil ports A and A1 of the compression valve block are connected through internal channel one. A one-way balance valve two is provided on internal channel one. The oil ports B and B1 of the compression valve block are connected through internal channel two. The oil ports A21 and A22 of the compression valve block are connected through internal channel three. The oil ports B21 and B22 of the compression valve block are connected through internal channel four. Internal channel three and internal channel two are cross-connected. The sides of internal channel one and internal channel two are connected through internal channel five. A safety valve two is provided on internal channel five. The side of internal channel one is connected to the side of internal channel four through internal channel six. A sequence valve and a one-way balance valve one are sequentially provided on internal channel six. The pilot control oil circuit of one-way balance valve two is connected to the side of internal channel two. The pilot control oil circuit of one-way balance valve one is connected to the side of the pilot control oil circuit of one-way balance valve two. A pressure switch is also connected to the side of internal channel one.

[0012] The hydraulic system of the compression mechanism of the garbage collection vehicle of the present invention mainly consists of a dual hydraulic pump, a push plate cylinder, a sliding plate cylinder, a scraper cylinder, a reversing valve, a back pressure valve, a safety valve, a sequence valve, and connecting pipelines.

[0013] The dual pump system has two pumps, Pump 1 and Pump 2, which respectively supply power to the push plate cylinder and the scraper plate cylinder. They can also combine to provide a large flow rate to the scraper plate. Reversing valves 1 and 4 enable no-load starting of the dual pump system, ensuring flexible no-load starting of the motor. Simultaneously, by switching reversing valve 1, Pump 1 can supply oil to the push plate cylinder separately, or it can combine with Pump 2 via a check valve to simultaneously supply oil to the scraper plate.

[0014] The rodless chamber of the push plate cylinder is equipped with a back pressure valve. The pilot control port of the back pressure valve is connected to the rodless chamber of the sliding plate cylinder to obtain the oil pressure of the rodless chamber. When the sliding plate cylinder drives the garbage upward into the box, the push plate cylinder is locked because the second directional valve is not energized and is in the neutral position. The upward garbage is continuously compressed under the action of the front and rear sliding plates and the push plate. When it is compressed to a certain density, the oil pressure in the rodless chamber of the sliding plate cylinder rises, and the pressure transmitted to the pilot control port of the back pressure valve of the push plate cylinder also rises. When the pressure rises to the point that it opens the spring at the left end of the pilot valve, the valve core moves to the left, the back pressure valve is opened, and the hydraulic oil in the rodless chamber of the push plate flows back to the oil tank through the back pressure valve. The push plate begins to retract. The back pressure valve integrates an overflow valve as the back pressure when the push plate retracts to prevent uneven speed and vibration during the retraction of the push plate. At this time, the garbage in the scraper plate is compressed and moved upward, and the garbage loading is completed.

[0015] An unloading valve is installed in the rodless chamber of the push plate to release pressure without load in the rodless chamber of the push plate, so as to realize the rapid retraction of the push plate cylinder.

[0016] Similarly, a safety valve is installed on the rodless chamber side of the push plate to protect the push plate piston rod from overload. When the push plate is subjected to load pressure, the push plate back pressure valve will open when a certain level is reached, allowing hydraulic oil in the push plate rodless chamber to flow out and the push plate piston rod to retract. To ensure smooth retraction of the push plate, an overflow valve is integrated into the back pressure valve. However, if the overflow valve malfunctions or fails to open for other reasons, the force on the push plate will increase, and the force on the push plate piston rod will also increase. Because the push plate stroke is long and the piston rod is also long, excessive pressure can cause the push plate piston rod to become unstable, leading to damage to the push plate cylinder. Safety valve one is designed to prevent this from happening. When safety valve one opens, it indicates that the push plate or back pressure valve is malfunctioning. The pressure transmitter after safety valve one is to prompt the operator to troubleshoot the problem in time, while the one-way throttle valve before the pressure transmitter provides the necessary sensing pressure for the pressure transmitter to operate.

[0017] The compression valve block is equipped with oil inlets A and B, and oil outlets A1, B1, A21, B21, A22, and B22. A1 and B1 are connected to the scraper cylinder, and A1, B1, A21, B21, A22, and B22 are connected to the slide plate cylinder. The compression valve block is equipped with a one-way balance valve II, which provides back pressure when the scraper cylinder retracts. At this time, the scraper mechanism opens, which can ensure that the operation is smooth and does not stall when opening, especially when the two pumps are combined. The system integrates a sequence valve to achieve the sequential action of scraper closure and slide plate upward compression during material collection. It also integrates a one-way balance valve to enable the scraper mechanism to open during the preparation stage of scraping waste, and then the slide plate mechanism to slide down to the top of the hopper of the collection vehicle to complete the preparation work for scraping waste. The system also integrates a safety valve to protect the scraper mechanism. When the scraper mechanism is closed, if the amount of waste is too large, the scraper closing force will be too large, which may cause deformation or damage to the scraper mechanism components. The safety valve can limit the scraper closing force in time.

[0018] A reversing valve three is provided to facilitate maintenance when the compression mechanism malfunctions and the casing needs to be accessed for repairs. In such cases, it is desirable to retract the scraper mechanism to the front of the casing for easy maintenance. This system adds an emergency control circuit by connecting a reversing valve to the A21 and B21 oil ports of the compression valve block. When the scraper mechanism malfunctions, the reversing valve three is operated separately to open the scraper mechanism and move the slide plate mechanism upwards, returning it to its initial position. The reversing valve three has an O-type neutral position function and an oil lock function, thus not affecting the normal use of the compression valve block.

[0019] The second objective of this invention is to provide a working method for the hydraulic system of the compression mechanism of a garbage collection vehicle, which can improve the garbage compression rate and efficiency, protect the compression mechanism, and facilitate personnel maintenance.

[0020] The objective of this invention is achieved as follows: a method for operating the hydraulic system of the compression mechanism of a garbage collection vehicle, comprising the following steps: Compression Preparation Stage: When the collection vehicle collects garbage, after the garbage hopper of the compactor is full, the piston rod of the push plate cylinder is extended to its full position. This controls the merging of hydraulic pumps one and two, which then enter the compression valve block through port B. High-pressure oil flows directly into the rod chamber of the scraper cylinder through channel BB1, and then through ports A21 and A22 of the compression valve block into the rod chamber of the sliding plate cylinder. Simultaneously, pressurized oil enters the pilot control chambers of one-way balance valve one and one-way balance valve two. Oil in the rodless chamber of the scraper cylinder reaches one-way balance valve two through port A1. Hydraulic oil in the rodless chamber of the sliding plate cylinder flows through ports B21 and... When the pressure rises to 35 bar, the pressure oil first opens the one-way balance valve 1 because the opening set pressure of the one-way balance valve 1 is greater than that of the one-way balance valve 2. The rodless chamber of the scraper oil returns first, and the scraper moves first to open. After the scraper opens to the correct position, the system pressure continues to rise to 50 bar. Under the push of the pilot pressure oil, the valve core of the one-way balance valve 1 moves to the left to open, the piston rod of the slide plate cylinder begins to retract, and the slide plate mechanism moves down to the top of the packer hopper, completing the preparation work before scraping and collecting garbage. Compression Stage: When scraping garbage, after the dual pumps merge, the reversing valve controls the high-pressure oil to enter the compression valve block from port A, pass through the one-way valve in the second one-way balance valve to port A1, and then enter the rodless chamber of the scraper cylinder. The oil returning from the rod chamber of the scraper cylinder passes through port B1 and flows back to the oil tank through channel B1B. The scraper cylinder extends, and the scraper mechanism begins to scrape garbage. After the scraper reaches its position, the pressure rises, and the pressure at port A1 increases by 100 bar. The pressurized oil enters the left control oil passage of the sequence valve, pushing the valve core of the sequence valve to move to the right, opening the sequence valve. The high-pressure oil passes through the sequence valve and then through the one-way valve in the first one-way balance valve to enter the B21B22 oil passage of the compression valve block, and then enters the rodless chamber of the slide plate cylinder. The slide plate cylinder extends, and when the piston rod of the slide plate cylinder extends, it compresses the garbage. The slide plate carries the scraper upward. As the upward distance increases, the garbage compression density increases, and the pressure inside the slide plate cylinder increases. The pressure switch senses pressure P1, and P1... The pressure initially reaches 130 bar, then switches to a large pump (Pump 1) for oil supply, entering the pressurization stage. The pressure continues to rise to P2, which reaches 220 bar. At this point, the pressure switches to a small pump (Pump 2) for oil supply, entering the high-pressure stage until compression is complete, achieving garbage loading. During this process, the oil pressure in the rodless chamber of the sliding plate is transmitted to the pilot port of the back pressure valve in the rodless chamber of the pusher cylinder. After the garbage reaches a certain density, the pressure in the rodless chamber of the sliding plate rises. At this density, the oil pressure reaches the set pressure of 140 bar in the hydraulic pilot valve of the back pressure valve, pushing the hydraulic pilot valve to move. The overflow valve in the back pressure valve opens, allowing hydraulic oil in the rodless chamber of the pusher cylinder to enter the back pressure valve. Simultaneously, the hydraulic oil returns to the oil tank from back pressure valve 1, causing the pusher to retract smoothly. The back pressure valve closes again when the pressure in the rodless chamber of the sliding plate cylinder drops below the set pressure of the hydraulic pilot valve, stopping the pusher mechanism from retracting and completing the garbage compression and loading into the container. Unloading garbage: When the garbage truck is full, it will transport the garbage to the garbage transfer station for secondary processing, or directly to the garbage treatment plant for processing. After arriving at the treatment plant, the hydraulic pump will be started to open the packer and lift it into place. The hydraulic oil will enter the rodless chamber of the pusher cylinder by controlling the reversing valve. The piston rod of the pusher cylinder will extend and the pusher will push the garbage out of the box to complete the unloading. Then the reversing valve will switch the high pressure oil to enter the rod chamber of the pusher cylinder. At the same time, the unloading valve will be opened and the hydraulic oil in the rodless chamber of the pusher will return directly to the oil tank. The pusher will quickly retreat to the position to complete the unloading.

[0021] As a further improvement of the present invention, when the scraper plate mechanism or related hydraulic system components malfunction and need to be repaired, the small pump is started to supply oil, the reversing valve is controlled to switch to the right position, the hydraulic oil enters the rod chamber of the scraper cylinder, the scraper opens, and then the reversing valve is switched to the left position, the high pressure oil enters the rodless chamber of the slide plate cylinder, the slide plate moves upward, so that the scraper and slide plate mechanism move upward to the initial position, and the worker can start to enter the box for maintenance.

[0022] Compared with existing technologies, the beneficial effects of this invention are as follows: 1. This system can achieve separate oil supply from a large pump to the compression mechanism, separate oil supply from a small pump to the compression mechanism, and combined oil supply from two pumps to the compression mechanism, thereby regulating the compression cycle speed. When the compression mechanism is unloaded and descending, the descent speed can be accelerated. During the upward compression process, the compression resistance is low in the first half, which can increase the compression speed, while the compression resistance is high in the second half, which can reduce the speed and increase the compression force, thereby improving the compression ratio and compression efficiency. 2. This system, by incorporating a compression valve block and integrating a sequence valve, a one-way balance valve, and an overflow valve, achieves a cycle of scraper opening - slide plate descending preparation - scraper closing - slide plate ascending compression in the compression mechanism, realizing automated cyclic compression. It also functions as a protection mechanism against potential overload situations. 3. This system has an emergency maintenance operation function. Through a separate control circuit, the scraper slide mechanism can be operated independently. When a fault occurs and maintenance is required, the scraper is opened, and the slide plate moves upward, releasing the waste and creating space for maintenance personnel to enter the container for repairs. 4. This system is equipped with safety protection and fault alarm functions for the push plate cylinder. When the system malfunctions and the push plate mechanism cannot retract normally, a safety valve is provided to protect the push plate mechanism from damage. When the pressure is too high, the push plate can be retracted, and an alarm will be set up in time to prompt the staff to carry out maintenance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the hydraulic system of the present invention.

[0024] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0025] Figure 3 This is a schematic diagram of the reversing valve three.

[0026] Figure 4 for Figure 1 A magnified view of a portion of the image.

[0027] Figure 5 This is a schematic diagram of the back pressure valve block.

[0028] Figure 6 This is a schematic diagram of the compression valve block.

[0029] Figure 7 This is a schematic diagram of the compression mechanism of a garbage collection truck.

[0030] Figure 8 This is a three-dimensional structural diagram of the compression mechanism of a garbage collection truck.

[0031] The system includes: 1. Double hydraulic pump; 1a. Pump 1; 1b. Pump 2; 2. Relief valve 1; 3. Directional valve 1; 4. Check valve; 5. Directional valve 2; 6. Directional valve 3; 7. Unloading valve; 8. Push plate cylinder; 8a. Push plate; 9. Back pressure valve block; 91. Hydraulic pilot valve; 92. Relief valve 3; 93. Back pressure valve 1; 94. Hydraulic flow channel; 10. Safety valve 1; 11. One-way throttle valve; 12. Pressure transmitter; 13. Scraper cylinder; 13a. Scraper; 14. Compression valve block; 1401. Safety valve 2; 1402. One-way balance valve 1; 1403. Sequence valve; 1404. One-way balance valve 2; 1405. Pressure... 15 Switch, 15 Slide Cylinder, 15a Slide, 16 Directional Valve IV, 17 Relief Valve II, 18 Return Oil Filter, 19 Hydraulic Oil Tank, 20 Oil Pipeline I, 21 Oil Pipeline II, 22 Oil Pipeline III, 23 Oil Pipeline IV, 24 Connecting Pipeline I, 25 Connecting Pipeline II, 26 Oil Pipeline V, 27 Oil Pipeline VI, 28 Oil Pipeline VII, 29 Oil Pipeline VIII, 30 Oil Pipeline IX, 31 Oil Pipeline X, 32 Internal Channel I, 33 Internal Channel II, 34 Internal Channel III, 35 Internal Channel IV, 36 Internal Channel V, 37 Internal Channel VI, 38 Pilot Control Oil Circuit, 39 Packer Hopper. Detailed Implementation

[0032] like Figure 1-8 As shown, a hydraulic system for the compression mechanism of a garbage collection vehicle includes a push plate cylinder 8, a scraper cylinder 13, and a sliding plate cylinder 15. Corresponding to the push plate cylinder 8, scraper cylinder 13, and sliding plate cylinder 15, there are compression valve blocks 14, back pressure valve blocks 9, and several directional valves. The hydraulic oil tank 19 supplies oil to the push plate cylinder 8, scraper cylinder 13, and sliding plate cylinder 15 through a double hydraulic pump 1, each directional valve, and the compression valve block 14 and back pressure valve block 9.

[0033] To facilitate the reversing of the oil circuit, four reversing valves are provided. Reversing valve 1 (3) and reversing valve 4 (16) have the same structure, and both reversing valve 1 (3) and reversing valve 4 (16) have A, B, P, and T oil ports in their middle positions. Reversing valve 2 (5) and reversing valve 3 (6) have the same structure, and both reversing valve 2 (5) and reversing valve 3 (6) have A, B, P, and T oil ports in their middle positions.

[0034] The dual hydraulic pump 1 includes pump 1a and pump 1b. The hydraulic oil tank 19 is connected to the inlets of pump 1a and pump 1b via two connecting pipes. The outlets of pump 1a and pump 1b are connected to the P ports of directional valve 3 and directional valve 4 16 via oil pipe 1 20 and oil pipe 2 21, respectively. The T port of directional valve 4 16 is connected to one end of return oil filter 18 via oil pipe 3 22. The other end of return oil filter 18 is connected to the hydraulic oil tank 19. The T port of directional valve 3 is connected to the side of oil pipe 3 22 via oil pipe 4 23. A connecting pipe is provided between oil pipe 4 23 and the side of oil pipe 1 20. A relief valve 2 is installed on connecting pipe 24. A connecting pipe 25 is installed between the sides of oil pipe 21 and oil pipe 32. A relief valve 27 is installed on connecting pipe 25. The P ports of reversing valve 36 and reversing valve 25 are connected to the A port of reversing valve 3. The T ports of reversing valve 36 and reversing valve 25 are connected to the connection port of connecting pipe 25 and oil pipe 32. The compression valve block 14 is provided with oil inlet ports A and B and oil outlet ports A1, B1, A21, B21, A22 and B22. Oil inlet ports A and B of compression valve block 14 are respectively connected to reversing valve 41. Oil ports A and B of 6 are connected. Oil pipe 5 26 is connected to the side of the connecting pipeline between oil port A of compression valve block 14 and oil port A of reversing valve 4 16. The other end of oil pipe 5 26 is connected to oil port B of reversing valve 1 3. A check valve 4 is provided on oil pipe 5 26. Oil ports A1 and B1 of compression valve block 14 are respectively connected to the rodless chamber and rod chamber of scraper cylinder 13. Oil ports A21 and B21 of compression valve block 14 are respectively connected to the rod chamber and rodless chamber of slide cylinder 15 via oil pipe 6 27 and oil pipe 7 28. Oil ports A22 and B22 of compression valve block 14 are respectively connected to the rod chamber of another slide cylinder 15. The reversing valve 36 has a rodless chamber and a rodless chamber. The oil port A of the reversing valve 36 is connected to the side of the oil pipeline 627. The oil port B of the reversing valve 36 is connected to the side of the oil pipeline 728 via the oil pipeline 829. The oil port A of the reversing valve 25 is connected to the rod chamber of the push plate cylinder 8. The oil port B of the reversing valve 25 is connected to the rodless chamber of the push plate cylinder 8 via the oil pipeline 930. The back pressure valve block 9 is provided with P, T and PIL oil ports respectively. The P oil port of the back pressure valve block 9 is connected to the side of the oil pipeline 930 via the oil pipeline 1031. The T oil port of the back pressure valve block 9 is connected to the hydraulic oil tank 19. The hydraulic control oil port PIL of the back pressure valve block 9 is connected to the side of the oil pipeline 829.

[0035] There are two scraper cylinders 13. Two scraper cylinders 13 drive the scraper mechanism more smoothly.

[0036] The back pressure valve block 9 is equipped with a relief valve 3 92, a back pressure valve 1 93, and a hydraulic pilot valve 91. The inlet of the relief valve 3 92 is connected to the P port of the back pressure valve block 9, the outlet of the relief valve 3 92 is connected to the inlet of the back pressure valve 1 93, the outlet of the back pressure valve 1 93 is connected to the T port of the back pressure valve block 9, the spring chamber of the relief valve 3 92 is connected to the inlet of the hydraulic pilot valve 91, the outlet of the hydraulic pilot valve 91 is connected to the T port of the back pressure valve block 9, and the hydraulic flow channel 94 of the hydraulic pilot valve 91 is connected to the hydraulic port PIL of the back pressure valve block 9.

[0037] The side of oil line 1031 is connected to the inlet of safety valve 10. The outlet of safety valve 10 is connected to the inlet of one-way throttle valve 11. The outlet of one-way throttle valve 11 is connected to hydraulic oil tank 19. The side of the connecting pipe between the inlet of one-way throttle valve 11 and the outlet of safety valve 10 is connected to pressure transmitter 12. The connection port between the side of oil line 1031 and oil line 930 is also connected to port A of unloading valve 7. Port B of unloading valve 7 is connected to hydraulic oil tank 19.

[0038] The compression valve block 14 has several internal channels. Ports A and A1 of the compression valve block 14 are connected via internal channel 1 32. A one-way balance valve 2 1404 is installed on internal channel 1 32. Ports B and B1 of the compression valve block 14 are connected via internal channel 2 33. Ports A21 and A22 of the compression valve block 14 are connected via internal channel 34. Ports B21 and B22 of the compression valve block 14 are connected via internal channel 4 35. Internal channel 34 and internal channel 2 33 are interconnected. The sides of internal channels 1 32 and 2 33 are connected via internal channel 5 3. The six-phase system is interconnected. Safety valve 2 1401 is installed on inner channel 5 36. The side of inner channel 1 32 is connected to the side of inner channel 4 35 through inner channel 6 37. Sequence valve 1403 and one-way balance valve 1 1402 are installed sequentially on inner channel 6 37. The pilot control oil circuit 38 of one-way balance valve 2 1404 is connected to the side of inner channel 2 33. The pilot control oil circuit 38 of one-way balance valve 1 1402 is connected to the side of the pilot control oil circuit 38 of one-way balance valve 2 1404. Pressure switch 1405 is also connected to the side of inner channel 1 32.

[0039] The compression mechanism of the garbage collection vehicle includes a scraper 13a, a sliding plate 15a, and a pusher 8a mechanism. The scraper cylinder, sliding plate cylinder, and pusher cylinder drive the scraper, sliding plate, and pusher mechanisms, respectively.

[0040] A method for operating a hydraulic system for a compression mechanism of a garbage collection vehicle includes the following steps: Compression Preparation Stage: When the collection vehicle collects garbage, after the garbage in the hopper 39 of the compactor is filled, the piston rod of the pusher cylinder 8 is extended to the position. This controls the hydraulic pumps 1a and 1b to merge and enter the compression valve block 14 through port B. High-pressure oil flows directly into the rod chamber of the scraper cylinder 13 through channel BB1, and then through ports A21 and A22 of the compression valve block 14 into the rod chamber of the sliding plate cylinder 15. Simultaneously, pressurized oil enters the pilot control chambers of check valves 4a and 4b. Oil in the rodless chamber of the scraper cylinder 13 reaches the one-way balance valve 1404 through port A1. Hydraulic oil in the rodless chamber of the sliding plate cylinder 15 flows through port B21... When the pressure rises to 35 bar, the pressure oil first opens the one-way balance valve 1404 first because the opening set pressure of the one-way balance valve 1402 is greater than that of the one-way balance valve 2404. The rodless chamber of the scraper oil returns first, and the scraper moves first to open. After the scraper opens to the correct position, the system pressure continues to rise to 50 bar. Under the push of the pilot pressure oil, the valve core of the one-way balance valve 1402 moves to the left to open, the piston rod of the slide cylinder 15 begins to retract, and the slide mechanism moves down to the top of the packer hopper, completing the preparation work before scraping and collecting garbage. Compression Stage: When scraping garbage, after the two pumps merge, the reversing valve controls the high-pressure oil to enter the compression valve block 14 from port A, pass through the one-way valve 4 in the one-way balance valve 1404, reach port A1, and then enter the rodless chamber of the scraper cylinder 13. The oil returning from the rod chamber of the scraper cylinder 13 passes through port B1, through the flow channel B1B, and returns to the oil tank. The scraper cylinder 13 extends, and the scraper mechanism begins to scrape garbage. After the scraper reaches its position, the pressure rises, and the pressure at port A1 rises by 100 bar. The pressurized oil then flows to the sequence valve 1403 and enters the sequence valve 1. The left-side control oil passage 403 pushes the valve core of sequence valve 1403 to move to the right, opening sequence valve 1403. High-pressure oil passes through sequence valve 1403 and then through the one-way valve in one-way balance valve 1402 into the B21-B22 oil passages of compression valve block 14. It then enters the rodless chamber of slide plate cylinder 15, extending the piston rod. As the piston rod extends, the waste is compressed, and the slide plate, carrying the scraper, moves upwards. The greater the upward distance, the higher the waste compression density and the higher the pressure inside slide plate cylinder 15. Pressure switch 1405 senses pressure P1, which is 130 bar, and then switches to the large pump supply (Pump 1) to enter the pressurization stage. The pressure then continues to rise to P2, which is 220 bar, at which point it switches to the small pump supply (Pump 2) to enter the high-pressure stage, continuing until compression is achieved, thus loading the waste. During this process, the oil pressure in the rodless chamber of the slide plate is transmitted to the back pressure valve pilot port of the rodless chamber of the pusher cylinder 8. After the waste reaches a certain density, the pressure in the rodless chamber of the slide plate increases. At this density, the oil pressure reaches the set pressure of 140 bar in the hydraulic pilot valve 91 of the back pressure valve, pushing the hydraulic pilot valve 91 to move. The overflow valve in the back pressure valve opens, and the hydraulic oil in the rodless chamber of the push plate cylinder 8 enters the back pressure valve. At the same time, the hydraulic oil returns to the oil tank through the back pressure valve 93, allowing the push plate to move backward smoothly. Until the pressure in the rodless chamber of the slide plate cylinder 15 drops below the set pressure of the hydraulic pilot valve 91 of the back pressure valve, the back pressure valve closes again, the push plate mechanism stops moving backward, and the garbage compression and loading into the box is completed. Unloading garbage: When the garbage truck is full, it will transport the garbage to the garbage transfer station for secondary processing, or directly to the garbage treatment plant for processing. After arriving at the treatment plant, the hydraulic pump will be started to open the packer and lift it into place. The hydraulic oil will enter the rodless chamber of the push plate cylinder by controlling the reversing valve. The piston rod of the push plate cylinder 8 will extend and the push plate will push the garbage in the box outward to complete the unloading. Then the reversing valve will switch the high pressure oil into the rod chamber of the push plate cylinder 8. At the same time, the unloading valve 7 will be opened and the hydraulic oil in the rodless chamber of the push plate will return directly to the oil tank. The push plate will quickly retreat to the position to complete the unloading.

[0041] The emergency operation for this system is as follows: When the scraper plate mechanism or related hydraulic system components malfunction and require repair, start the small pump to supply oil, control the reversing valve 36 to switch to the right position, hydraulic oil enters the rod chamber of scraper cylinder 13, the scraper opens, then switch the reversing valve to the left position, high pressure oil enters the rodless chamber of slide plate cylinder 15, the slide plate moves upward, causing the scraper plate mechanism to move upward to the initial position, and the worker can then enter the housing for repair.

[0042] The advantages of this invention are as follows: 1. This system can achieve separate oil supply from a large pump, separate oil supply from a small pump, and combined oil supply from two pumps, allowing the compression mechanism to adjust its operating speed in a timely manner according to the load size, achieving rapid downward movement. During the garbage compression process, it achieves a combination of rapid compression and high pressure, moving quickly under no-load or light-load conditions and slowly under heavy load, ensuring both the compression density of the garbage and increasing the compression operation time, thus improving the efficiency of the compression cycle. 2. This system, through the inclusion of a compression valve block 14, can achieve an automatic cycle of scraper opening - slide plate downward preparation - scraper closing - slide plate upward compression. The built-in pressure valve automatically switches actions, saving on complex configurations such as hydraulic control and position sensor control. The system is simple, reliable, simplifies the control logic and reduces costs, saves on pipeline and wiring installation, and facilitates maintenance. 3. This system is equipped with an emergency control system. When the compression mechanism malfunctions and requires maintenance, the compression mechanism can be manually operated to reset the scraper slide mechanism to its initial position, freeing up space for maintenance. 4. This system is equipped with safety protection and fault alarm functions for the pusher cylinder 8. In the event of a malfunction in the pusher mechanism or hydraulic system during compression, the pusher can retract promptly to prevent damage from excessive pressure and to alert personnel for repairs. 5. This system has a protective function for the scraper mechanism. When the scraper encounters a large amount of debris, it can limit the maximum closing force of the scraper mechanism, protecting it from deformation or damage.

[0043] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A hydraulic system for the compression mechanism of a garbage collection vehicle, comprising a pusher cylinder, a scraper cylinder, and a sliding plate cylinder, characterized in that, A compression valve block, a back pressure valve block, and several directional valves are provided corresponding to the push plate cylinder, scraper cylinder, and slide plate cylinder. The hydraulic oil tank supplies oil to the push plate cylinder, scraper cylinder, and slide plate cylinder through a double hydraulic pump, each directional valve, and the compression valve block. The dual hydraulic pumps include pump one and pump two. The hydraulic oil tank is connected to the inlets of pump one and pump two via two connecting pipes, respectively. The outlets of pump one and pump two are connected to the P ports of directional valve one and directional valve four via oil pipe one and oil pipe two, respectively. The T port of directional valve four is connected to one end of the return oil filter via oil pipe three, and the other end of the return oil filter is connected to the hydraulic oil tank. The T port of directional valve one is connected to the side of oil pipe three via oil pipe four. A connecting pipe one is provided between oil pipe four and the side of oil pipe one, and an overflow valve is provided on connecting pipe one. A connecting pipe 2 is provided between the sides of valve 1, oil line 2, and oil line 3. An overflow valve 2 is installed on the connecting pipe 2. The P port of directional valve 3 and the P port of directional valve 2 are both connected to the A port of directional valve 1. The T port of directional valve 3 and the T port of directional valve 2 are both connected to the connection port of connecting pipe 2 and oil line 3. The compression valve block has inlet ports A and B, and outlet ports A1, B1, A21, B21, A22, and B22. Ports A and B of the compression valve block are respectively connected to port A of directional valve 4. Connected to B, the oil pipe between port A of the compression valve block and port A of the reversing valve four is connected to oil pipe five on the side. The other end of oil pipe five is connected to port B of the reversing valve one. A check valve is installed on oil pipe five. Ports A1 and B1 of the compression valve block are connected to the rodless chamber and rod chamber of the scraper cylinder, respectively. Ports A21 and B21 of the compression valve block are connected to the rod chamber and rodless chamber of the slide block cylinder via oil pipe six and oil pipe seven, respectively. Ports A22 and B22 of the compression valve block are connected to the rod chamber and rodless chamber of another slide block cylinder, respectively. The oil port A of the reversing valve three is connected to the side of oil pipeline six, and the oil port B of the reversing valve three is connected to the side of oil pipeline seven via oil pipeline eight. The oil port A of the reversing valve two is connected to the rod chamber of the push plate cylinder, and the oil port B of the reversing valve two is connected to the rodless chamber of the push plate cylinder via oil pipeline nine. The back pressure valve block is provided with P, T and PIL oil ports respectively. The P oil port of the back pressure valve block is connected to the side of oil pipeline nine via oil pipeline ten. The T oil port of the back pressure valve block is connected to the hydraulic oil tank. The hydraulic control oil port PIL of the back pressure valve block is connected to the side of oil pipeline eight. The compression valve block has several internal channels. Ports A and A1 of the compression valve block are connected through internal channel one. A one-way balance valve two is installed on internal channel one. Ports B and B1 of the compression valve block are connected through internal channel two. Ports A21 and A22 of the compression valve block are connected through internal channel three. Ports B21 and B22 of the compression valve block are connected through internal channel four. Internal channel three is intersecting and connected to internal channel two. The sides of internal channels one and two are connected through internal channel five. A safety valve two is installed on internal channel five. The side of internal channel one is connected to the side of internal channel four through internal channel six. A sequence valve and a one-way balance valve one are sequentially installed on internal channel six. The pilot control oil circuit of one-way balance valve two is connected to the side of internal channel two. The pilot control oil circuit of one-way balance valve one is connected to the side of the pilot control oil circuit of one-way balance valve two. A pressure switch is also connected to the side of internal channel one.

2. The hydraulic system of the compression mechanism of a garbage collection vehicle according to claim 1, wherein four reversing valves are provided, the first reversing valve and the fourth reversing valve have the same structure, and the middle position of the first reversing valve and the fourth reversing valve are respectively provided with oil ports A, B, P, and T; the second reversing valve and the third reversing valve have the same structure, and the middle position of the second reversing valve and the third reversing valve are respectively provided with oil ports A, B, P, and T.

3. The hydraulic system for the compression mechanism of a garbage collection vehicle according to claim 1, characterized in that, There are two scraper cylinders.

4. The hydraulic system for the compression mechanism of a garbage collection vehicle according to claim 1, characterized in that, The back pressure valve block is internally equipped with a relief valve three, a back pressure valve one, and a hydraulic pilot valve. The inlet of the relief valve three is connected to the P port of the back pressure valve block, the outlet of the relief valve three is connected to the inlet of the back pressure valve one, the outlet of the back pressure valve one is connected to the T port of the back pressure valve block, the spring chamber of the relief valve three is connected to the inlet of the hydraulic pilot valve, the outlet of the hydraulic pilot valve is connected to the T port of the back pressure valve block, and the hydraulic flow channel of the hydraulic pilot valve is connected to the hydraulic port PIL of the back pressure valve block.

5. The hydraulic system for the compression mechanism of a garbage collection vehicle according to claim 4, characterized in that, The side of oil pipeline 10 is connected to the inlet of safety valve 1, the outlet of safety valve 1 is connected to the inlet of one-way throttle valve, the outlet of one-way throttle valve is connected to the hydraulic oil tank, the side of the connecting pipeline between the inlet of one-way throttle valve and the outlet of safety valve 1 is connected to the pressure transmitter, the connecting port on the side of oil pipeline 10 and oil pipeline 9 is also connected to port A of unloading valve, and port B of unloading valve is connected to the hydraulic oil tank.

6. The working method of the hydraulic system of the compression mechanism of a garbage collection vehicle according to claim 5, characterized in that, Includes the following steps: Compression Preparation Stage: When the collection vehicle collects garbage, after the garbage hopper of the compactor is full, the piston rod of the push plate cylinder is extended to its full position. Hydraulic oil is pumped through pump two to reversing valve four and enters the compression valve block from port B. Hydraulic oil is also pumped through pump one to reversing valve one and reversing valve three and enters the rod chamber of the slide plate cylinder. High-pressure oil enters the rod chamber of the scraper cylinder directly through the BB1 ​​flow channel. At the same time, pressure oil enters the pilot control chambers of one-way balance valve one and one-way balance valve two. The oil in the rodless chamber of the scraper cylinder reaches one-way balance valve two through port A1. The hydraulic oil in the rodless chamber of the slide plate cylinder enters through port B2. When the pressure rises to 35 bar, the pressure oil first opens the one-way balance valve 1 because the opening set pressure of the one-way balance valve 1 is greater than that of the one-way balance valve 2. The rodless chamber of the scraper cylinder returns oil first, and the scraper moves to open first. After the scraper opens to the position, the system pressure continues to rise to 50 bar. Under the push of the pilot pressure oil, the valve core of the one-way balance valve 1 moves to the left and opens. The piston rod of the slide cylinder begins to retract, and the slide mechanism moves down to the top of the packer hopper, completing the preparation work before scraping and collecting garbage. Compression Stage: When scraping garbage, after the dual pumps merge, the reversing valve controls the high-pressure oil to enter the compression valve block from port A, pass through the check valve in the second one-way balance valve to port A1, and then enter the rodless chamber of the scraper cylinder. The oil returning from the rod chamber of the scraper cylinder passes through port B1 and flow channel B1B back to the oil tank. The scraper cylinder extends, and the scraper mechanism begins to scrape garbage. After the scraper reaches its position, the pressure rises, and the pressure at port A1 increases by 100 bar. The pressurized oil enters the left control oil passage of the sequence valve, pushing the valve core of the sequence valve to move to the right, opening the sequence valve. The high-pressure oil passes through the sequence valve and then through the check valve in the first one-way balance valve to enter the B21B22 oil passage of the compression valve block, and then enters the rodless chamber of the slide plate cylinder. The slide plate cylinder extends, and when the piston rod of the slide plate cylinder extends, it compresses the garbage. The slide plate carries the scraper upward. The greater the upward distance, the more the garbage is compressed. The higher the density, the higher the pressure inside the slide plate cylinder. The pressure switch senses pressure P1, which is 130 bar, and then switches to the large pump for oil supply (Pump 2), entering the pressurization stage. The pressure continues to rise to P2, which is 220 bar, and then switches to the small pump for oil supply (Pump 1), entering the high-pressure stage until the compression is complete, thus loading the waste. During this process, the oil pressure in the rodless chamber of the slide plate is transmitted to the pilot port of the back pressure valve in the rodless chamber of the push plate cylinder. After the waste is compressed to a certain density, the pressure in the rodless chamber of the slide plate rises. At this density, the oil pressure reaches the set pressure of 140 bar in the hydraulic pilot valve of the back pressure valve, pushing the hydraulic pilot valve to move. The overflow valve in the back pressure valve opens, and the hydraulic oil in the rodless chamber of the push plate cylinder enters the back pressure valve. At the same time, the hydraulic oil returns to the oil tank by opening the first back pressure valve, allowing the push plate to move smoothly backward. When the pressure in the rodless chamber of the slide valve cylinder drops below the set pressure of the back pressure valve pilot valve, the back pressure valve closes again, the push plate mechanism stops retracting, and the garbage compression and loading into the box is completed. Unloading garbage: When the garbage truck is full, it will transport the garbage to the garbage transfer station for secondary processing, or directly to the garbage treatment plant for processing. After arriving at the treatment plant, the hydraulic pump will be started to open the packer and lift it into place. The hydraulic oil will then enter the rodless chamber of the push plate cylinder by controlling the second directional valve. The piston rod of the push plate cylinder will extend and the push plate will push the garbage out of the box to complete the unloading. After that, the high pressure oil will be diverted by the second directional valve to the rod chamber of the push plate cylinder. At the same time, the unloading valve will be opened and the hydraulic oil in the rodless chamber of the push plate will return directly to the oil tank. The push plate will then quickly retreat to the position to complete the unloading.

7. The working method of the hydraulic system of the compression mechanism of a garbage collection vehicle according to claim 6, characterized in that, When the scraper plate mechanism or related hydraulic system components malfunction and require repair, start the small pump to supply oil, control the reversing valve three to switch to the right position, hydraulic oil enters the rod chamber of the scraper cylinder, the scraper opens, then switch the reversing valve three to the left position, high pressure oil enters the rodless chamber of the slide plate cylinder, the slide plate moves upward, so that the scraper and slide plate mechanism move upward to the initial position, and the worker can start to enter the housing for maintenance.

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