Tank body rear door opening and closing system of tank type sanitation vehicle

Abstract

The invention discloses a tank body rear door opening and closing system of a tank type sanitation truck, and relates to the technical field of sanitation suction-type sewer scavengers. The rear door opening and closing system comprises a tank body and a rear door, a sealing rubber strip is arranged at a tank opening of the tank body, a distance adjusting mechanism used for adjusting the distance between the rear door and the tank body is arranged between the tank body and the rear door, the distance adjusting mechanism comprises a U-shaped adjusting seat arranged on the tank body, and inserting holes are formed in side arms at the two ends of the U-shaped adjusting seat; the two inserting holes are coaxially formed, threaded rods are inserted into the inserting holes, threaded adjusting knobs are connected to the threaded rods in a matched mode, the threaded adjusting knobs are located between the two side arms of the U-shaped adjusting base, and one ends of the threaded rods are hinged to the rear door; and a driving mechanism and a locking mechanism are arranged between the tank body and the rear door. The gap between the rear door and the tank opening is reduced through the distance adjusting mechanism, so that the sealing effect is recovered, frequent replacement of sealing rubber strips is not needed, the cost and the maintenance workload are reduced, the driving mechanism and the locking mechanism achieve automatic unlocking and locking of the rear door, and the labor intensity of workers is reduced.

Description

Technical Field

[0001] This invention relates to the field of sanitation vacuum truck technology, specifically to a tank-type sanitation truck tank rear door opening and closing system. Background Technology

[0002] Vacuum trucks are sanitation vehicles used for collecting, transferring, cleaning, and transporting sludge, sewage, and septic tanks. The vehicles are equipped with vacuum pumps and rely on the adjustment of the four-way valve in the pipeline to achieve the self-priming and pressure discharge functions of the tank. Due to the complexity of the suction medium, the rear door of the tank needs to be opened frequently to facilitate the cleaning of sediment inside the tank, and the sealing requirements of the rear door are relatively high.

[0003] The rear door of a typical vacuum truck is designed as follows: the top of the tank is connected by a fixed hinge, the side has two three-way connected door opening cylinders, and the side and bottom have 2-4 manual locking mechanisms to press the rear door to ensure a seal.

[0004] Although this type of vacuum truck's rear door structure can open and close the rear door, because the tank top hinge is fixed, after a period of use, the top of the tank may not seal properly and cannot be adjusted. This results in the need to frequently replace the sealing strips, increasing the cost of use and maintenance workload.

[0005] Meanwhile, the side manual locking mechanism requires manual tightening or loosening one by one, which is not only cumbersome, time-consuming and labor-intensive, but also makes it difficult to guarantee the safety of manual operation when the vehicle is fully loaded or the working environment is harsh. Summary of the Invention

[0006] The purpose of this invention is to provide a rear door opening and closing system for a tank-type sanitation vehicle to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a rear door opening and closing system for a tank-type sanitation vehicle, comprising a tank body and a rear door, wherein a sealing strip is provided at the opening of the tank body. A spacing adjustment mechanism for adjusting the distance between the rear door and the tank body is provided between the tank body and the rear door. The spacing adjustment mechanism includes a U-shaped adjustment seat on the tank body. Each side arm of the U-shaped adjustment seat has a hole. The two holes are arranged coaxially. A threaded rod is inserted into the hole. A threaded adjustment knob is connected to the threaded rod. The threaded adjustment knob is located between the two side arms of the U-shaped adjustment seat. One end of the threaded rod is hinged to the rear door. A drive mechanism for opening and closing the rear door is also provided between the tank body and the rear door; A locking mechanism is also provided between the tank body and the rear door to lock the rear door at the tank opening.

[0008] Preferably, the threaded rod has a connecting part at one end facing the rear door, and a hinge shaft is provided on the connecting part; a hinge seat is provided on the rear door, and the hinge shaft is rotatably connected to the hinge seat.

[0009] Preferably, one threaded adjustment knob is used, and the length of the threaded adjustment knob is the same as the distance between the two side arms of the U-shaped adjustment seat.

[0010] Preferably, there are two threaded adjustment knobs, both located between the two side arms of the U-shaped adjustment seat, and each threaded adjustment knob is attached to one side arm of the U-shaped adjustment seat.

[0011] Preferably, the drive mechanism includes a door opening cylinder, one end of which is hinged to the tank body and the other end of which is hinged to the rear door. The door opening cylinder is connected to the vehicle hydraulic circuit system via an oil pipe.

[0012] Preferably, the door opening cylinder includes an active door opening cylinder and a passive door opening cylinder, which are connected in series, and a bidirectional compensation valve is provided between the vehicle-mounted hydraulic circuit system and the active and passive door opening cylinders.

[0013] Preferably, the locking mechanism includes a locking cylinder, the cylinder body of which is fixed to the tank body, and the piston rod end of which is connected to a wedge-shaped locking block; a locking tongue that cooperates with the wedge-shaped locking block is correspondingly provided on the rear door, and the locking tongue is provided with a locking hole that matches the wedge-shaped surface of the wedge-shaped locking block; the locking cylinder is connected to the vehicle hydraulic oil circuit system through an oil pipe.

[0014] Preferably, the outer ring of the threaded adjustment knob is circular, and teeth are evenly distributed around the outer ring. A rack that meshes with the teeth of the outer ring of the threaded adjustment knob is slidably disposed on the can body. A gear that meshes with the rack is also rotatably disposed on the can body. A hexagonal head adjustment knob is coaxially fixed on one side of the gear.

[0015] Preferably, the tank body is provided with a rotating shaft seat, the gear is rotatably engaged with the rotating shaft seat through a rotating shaft, one end of the rack is fixedly connected to the slider, the tank body is provided with a fixed seat, the fixed seat is provided with a linear guide rail, and the slider is slidably engaged with the linear guide rail.

[0016] Preferably, at least two sets of the spacing adjustment mechanism are used.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, by incorporating a spacing adjustment mechanism, can precisely adjust the initial sealing gap between the rear door and the tank opening, ensuring uniform pressure on the sealing strip and effectively improving the sealing performance between the tank and the rear door. This prevents leakage during transportation. If the sealing strip's sealing performance deteriorates due to prolonged use, the spacing adjustment mechanism can be used to reduce the gap between the rear door and the tank opening, restoring a good seal. This eliminates the need for frequent replacement of the sealing strip, significantly reducing operating costs and maintenance workload.

[0018] 2. The drive mechanism of this invention employs a series connection of an active door-opening cylinder and a driven door-opening cylinder, along with a bidirectional compensation valve design. This achieves strictly synchronized operation of the two cylinders, preventing skewness during the opening and closing of the rear door, thus avoiding issues such as poor sealing and leakage of contaminants. The rod-side chamber of the active door-opening cylinder and the rodless chamber of the driven door-opening cylinder have the same volume, ensuring initial synchronization. Furthermore, the bidirectional compensation valve replenishes oil to both cylinders when system pressure increases, automatically correcting stroke deviations caused by leakage or wear. This ensures smooth and stable opening and closing of the rear door, preventing jamming or skewness and improving operational reliability and stability.

[0019] 3. The locking mechanism of this invention utilizes the cooperation between a wedge-shaped locking block and a locking tongue, combined with the driving force provided by a locking cylinder. The self-locking characteristic of the wedge-shaped surface achieves a tight seal between the rear door and the tank opening. The arrangement of multiple locking mechanisms ensures uniform force distribution across all parts of the rear door, and the sealing strip effectively guarantees a tight seal. No manual locking of the rear door is required; all locking and unlocking actions are completed simply by controlling the extension and retraction of the locking cylinder. This convenient and efficient operation significantly reduces manual labor intensity. Simultaneously, during the locking process, the thrust of the locking cylinder is converted into a significant pressure perpendicular to the rear door sealing surface via the wedge-shaped locking block, further enhancing the sealing performance. Furthermore, the wedge structure has a reliable self-locking function in the locked state, maintaining the locked state even in the event of accidental cylinder depressurization, effectively preventing accidents caused by accidental opening of the rear door and significantly improving safety during operation.

[0020] 4. This invention can drive all threaded adjustment knobs to rotate synchronously by adjusting one hexagonal head adjustment knob, realizing the linkage adjustment of multiple sets of spacing adjustment mechanisms, which greatly improves the adjustment efficiency and accuracy, and avoids the problem of inconsistent adjustment amounts of each set that may be caused by the traditional single adjustment method. This linkage adjustment structure is especially suitable for the setting of multiple sets of spacing adjustment mechanisms, which can significantly reduce the difficulty of operation and improve the convenience of adjustment work. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 (Side view, rear door closed); Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2(Top view, back door closed); Figure 3 This is a schematic diagram of the structure of the present invention (side view, rear door opening). Figure 4 This is a schematic diagram of the spacing adjustment mechanism of the present invention; Figure 5 This is a diagram showing the fit between the wedge-shaped locking block and the locking tongue of the present invention. Figure 6 This is a connection diagram of the oil circuit system of the present invention; Figure 7 This is a partial structural diagram of another embodiment of the spacing adjustment mechanism of the present invention; Figure 8 This is a diagram illustrating another embodiment of the spacing adjustment mechanism of the present invention.

[0022] In the picture: 1-Tank body, 11-Sealing strip, 2-Rear door, 21-Hinge seat, 3-U-shaped adjustment seat, 41-Threaded rod, 42-Connecting part, 43-Hinge shaft, 44-Threaded adjusting knob, 45-Rack, 46-Gear, 461-Rotating shaft, 47-Fixed seat, 471-Rotating shaft seat, 48-Hexagonal head adjusting knob, 491-Linear guide rail, 492-Slider 5-Door opening cylinder, 51-Active door opening cylinder, 52-Driven door opening cylinder 6-Locking cylinder, 61-Wedge locking block, 62-Locking tongue, 63-Fixed plate base, 64-Connecting rod, 71-Oil tank, 72-Oil pump, 73-Directional control valve, 741-Closing sequence valve, 742-Opening sequence valve, 75-Two-way compensation valve. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figures 1 to 5 As shown, a tank-type sanitation vehicle tank rear door opening and closing system includes a tank body 1 and a rear door 2, wherein a sealing strip 11 is provided at the tank opening of the tank body 1.

[0025] A spacing adjustment mechanism for adjusting the distance between the rear door 2 and the tank body 1 is provided between the tank body 1 and the rear door 2. The spacing adjustment mechanism includes a U-shaped adjustment seat 3 provided on the tank body 1. Each of the two side arms of the U-shaped adjustment seat 3 is provided with a socket (not shown in the figure). The two sockets are arranged coaxially. A threaded rod 41 is inserted into the socket. A threaded adjustment knob 44 is connected to the threaded rod 41. The threaded adjustment knob 44 is located between the two side arms of the U-shaped adjustment seat 3. One end of the threaded rod 41 is hinged to the rear door 2.

[0026] A drive mechanism for opening and closing the rear door 2 is also provided between the tank body 1 and the rear door 2.

[0027] A locking mechanism is also provided between the tank body 1 and the rear door 2 to lock the rear door 2 at the opening of the tank body 1.

[0028] Specifically, in this embodiment, the threaded rod 41 has a connecting portion 42 at one end facing the rear door 2, and a hinge shaft 43 is provided on the connecting portion 42; the rear door 2 is provided with a hinge seat 21, and the hinge shaft 43 is rotatably connected to the hinge seat 21. Specifically, the hinge seat 21 is a bearing seat, and both ends of the hinge shaft 43 are respectively interference-fitted with the inner ring of the bearing in the bearing seat, so that the rear door 2 can rotate smoothly around the hinge shaft 43, thereby realizing the opening and closing action of the rear door 2.

[0029] Specifically, in this embodiment, one or two threaded adjustment knobs 44 are used.

[0030] Taking one threaded adjusting knob 44 as an example: the threaded adjusting knob 44 is provided with a threaded hole (not shown in the figure) that mates with the threaded rod 41. The length of the threaded adjusting knob 44 is the same as the distance between the two side arms of the U-shaped adjusting seat 3. When the threaded adjusting knob 44 is placed between the two side arms of the U-shaped adjusting seat 3, both ends of the threaded adjusting knob 44 contact the inner surfaces of the two side arms of the U-shaped adjusting seat 3, respectively. In this way, the two ends of the threaded adjusting knob 44 are limited by the two side arms of the U-shaped adjusting seat 3, so that the threaded adjusting knob 44 and the threaded rod 41 cannot move without human interference, thereby stably fixing the connecting part 42 and the hinge shaft 43 on the U-shaped adjusting seat 3. When it is necessary to adjust the distance between the rear door 2 and the tank body 1, use a wrench or other adjustment tools to turn the threaded adjustment knob 44. During the turning process, since the threaded adjustment knob 44 is restricted from axial movement by the side arm of the U-shaped adjustment seat 3, the threaded rod 41 will move along its axis under the action of the threaded engagement. Then, through the connecting part 42 and the hinge shaft 43, the hinge end of the rear door 2 will move synchronously, so as to achieve precise adjustment of the initial sealing gap between the rear door 2 and the tank opening of the tank body 1, ensuring that the sealing strip 11 can be evenly pressurized and improving the sealing effect.

[0031] If two threaded adjustment knobs 44 are used, both threaded adjustment knobs 44 are located between the two side arms of the U-shaped adjustment seat 3, and each threaded adjustment knob 44 is in close contact with one side arm of the U-shaped adjustment seat 3. By turning the two threaded adjustment knobs 44 respectively, the axial position of the threaded rod 41 can be adjusted more precisely.

[0032] Preferably, the spacing adjustment mechanism comprises two sets, symmetrically arranged on the top of the tank 1 (e.g., Figure 2 As shown, each set of spacing adjustment mechanisms is connected to the hinge seat 21 on the corresponding side of the rear door 2. Through the coordinated adjustment of the two sets of spacing adjustment mechanisms, it can be ensured that the rear door 2 remains parallel to the opening of the tank body 1 during opening and closing, avoiding problems such as the rear door 2 tilting due to improper adjustment on one side, uneven force on the sealing strip 11, and thus affecting the sealing performance. The two sets of spacing adjustment mechanisms also enhance the connection strength and stability between the tank body 1 and the rear door 2.

[0033] Furthermore, the other end of the threaded rod 41 may be provided with an anti-disengagement part (not shown in the figure). The outer diameter of the anti-disengagement part is larger than the diameter of the insertion hole on the side arm of the U-shaped adjusting seat 3, so as to prevent the threaded rod 41 from accidentally disengaging from the U-shaped adjusting seat 3 and improve the safety of the mechanism operation.

[0034] Specifically, in this embodiment, the driving mechanism includes a door opening cylinder 5, one end of which is hinged to the tank body 1, and the other end of which is hinged to the rear door 2. The door opening cylinder 5 is connected to the vehicle's hydraulic circuit system.

[0035] Preferably, in this embodiment, the door opening cylinder 5 includes an active door opening cylinder 51 and a passive door opening cylinder 52, which are connected in series, and a bidirectional compensation valve 75 is provided between the vehicle-mounted hydraulic circuit system and the active door opening cylinder 51 and the passive door opening cylinder 52.

[0036] The rod-side chamber of the active door-opening cylinder 51 and the rodless chamber of the driven door-opening cylinder 52 have the same volume, thus achieving strict synchronization between the two cylinders; this eliminates motion errors caused by long-term use.

[0037] A two-way compensation valve 75 is added to the pipeline between the active door opening cylinder 51 and the driven door opening cylinder 52. When the active door opening cylinder 51 and the driven door opening cylinder 52 are fully extended, the system pressure increases and opens the two-way compensation valve 75 to replenish the oil in the sealed oil chamber between the two cylinders, thereby realizing the self-adjustment function of the stroke of the two cylinders. This effectively eliminates the stroke deviation caused by cylinder leakage or mechanical wear, ensuring that the active door opening cylinder 51 and the driven door opening cylinder 52 always maintain synchronous operation, and avoiding jamming or tilting of the rear door 2 during the opening and closing process.

[0038] Both the active door-opening cylinder 51 and the driven door-opening cylinder 52 have their cylinder bodies hinged to cylinder supports (not shown in the figure) on the tank body 1 via pins. The piston rods of both cylinders are hinged to cylinder connecting lugs (not shown in the figure) on the rear door 2 via pins. The active door-opening cylinder 51 and the driven door-opening cylinder 52 are symmetrically arranged on both sides of the spacing adjustment mechanism along the central axis of the tank body 1 (e.g., ...). Figure 2 (As shown). The dual-cylinder drive design provides greater driving torque, ensuring that the rear door 2 can smoothly and reliably complete the opening and closing action even under full load or harsh working conditions. At the same time, the symmetrically arranged cylinders can make the force even on both sides of the rear door 2, avoiding the rear door 2 from deflecting and jamming during the opening and closing process.

[0039] Specifically, in this embodiment, the locking mechanism includes a locking cylinder 6, the cylinder body of which is fixed to the tank body 1, and the piston rod end of the locking cylinder 6 is connected to a wedge-shaped locking block 61. A locking tongue 62 corresponding to the wedge-shaped locking block 61 is provided on the rear door 2. The locking tongue 62 has a locking hole (not shown in the figure) adapted to the wedge-shaped surface of the wedge-shaped locking block 61. The locking tongue 62 is a plate-like structure, with one end vertically fixed to the outer wall of the rear door 2 and the other end extending towards the tank body 1. The locking hole is opened on the plate surface of the extended end of the locking tongue 62, and the shape of the locking hole matches the cross-sectional shape of the wedge-shaped locking block 61. The inner wall surface of the locking hole is an inclined surface that fits against the wedge-shaped surface of the wedge-shaped locking block 61. When the piston rod of the locking cylinder 6 extends, the wedge-shaped locking block 61 is inserted into the lock hole of the locking tongue 62. Utilizing the self-locking property of the wedge-shaped surface, the rear door 2 is tightly pressed against the opening of the tank body 1, ensuring that the sealing strip 11 is fully compressed and a reliable seal is achieved.

[0040] The locking mechanism also includes a fixed plate seat 63, which is fixedly installed on the outer wall of the tank body 1. The cylinder end of the locking cylinder 6 is rigidly connected to the fixed plate seat 63 via a connecting rod 64 to ensure the stability of the locking cylinder 6 during operation. To further improve the locking effect and structural strength, multiple sets of the locking mechanism can be used, for example, one set can be set on each side and bottom of the tank body 1, so that all parts of the rear door 2 can be subjected to uniform locking force, avoiding excessive local force that could cause deformation or sealing failure of the rear door 2.

[0041] In addition, a wear-resistant coating, such as a titanium nitride coating, can be provided on the wedge-shaped surface of the wedge-shaped locking block 61 to improve its surface hardness and wear resistance and extend its service life; a wear-resistant bushing can also be embedded in the inner wall of the lock hole of the locking tongue 62 to further reduce the wear between the wedge-shaped locking block 61 and the locking tongue 62 and ensure that it can maintain good locking performance after long-term use.

[0042] A hydraulic lock (not shown in the figure) can also be installed on the control oil circuit of the locking cylinder 6. When the locking cylinder 6 locks the rear door 2, the hydraulic lock can lock the position of the cylinder piston rod to prevent the locking force from decreasing due to leakage in the hydraulic system, thereby ensuring the locking reliability of the rear door 2 during transportation.

[0043] In this embodiment, the vehicle-mounted hydraulic circuit system is a conventional technology, mainly including components such as an oil tank 71, an oil pump 72, and a reversing valve 73, as well as a sequence valve for controlling the unlocking and door opening (closing, locking) sequence. Figure 6 As shown, the sequence valve mainly includes a closing sequence valve 741 and an opening sequence valve 742. The above structure is a conventional implementation, and the specific connection method is not described in detail.

[0044] Furthermore, such as Figure 7 and Figure 8 As shown, the outer ring of the threaded adjustment knob 44 is circular, and teeth are evenly arranged around the outer ring of the threaded adjustment knob 44. A rack that meshes with the teeth of the outer ring of the threaded adjustment knob 44 is slidably arranged on the tank body 1. A gear 46 is also rotatably arranged on the tank body 1. A hexagonal head adjustment knob 48 is coaxially fixed on one side of the gear 46.

[0045] Specifically, a rotating shaft seat 471 is provided on the tank body 1. The gear 46 rotates and engages with the rotating shaft seat 471 via the rotating shaft 461. The gear 46 meshes with the rack 45 for transmission. One end of the rack 45 is fixedly connected to the slider 492. A fixed seat 47 is provided on the tank body 1, and a linear guide rail 491 is provided on the fixed seat 47. The slider 492 slides and engages with the linear guide rail 491. When it is necessary to adjust the threaded adjustment knob 44, the operator uses a wrench to turn the hexagonal head adjustment knob 48, which drives the gear 46 to rotate around its rotating shaft 461. The gear 46 drives the rack 45 to move linearly along the linear guide rail 491. The rack 45 drives all the threaded adjustment knobs 44 to rotate by meshing with the outer teeth of the threaded adjustment knobs 44. In this way, adjusting one hexagonal head adjustment knob 48 can simultaneously drive all threaded adjustment knobs 44 to rotate synchronously, realizing the linkage adjustment of multiple sets of spacing adjustment mechanisms. This greatly improves the adjustment efficiency and accuracy, and avoids the problem of inconsistent adjustment amounts between sets that may be caused by the traditional single adjustment method. This linkage adjustment structure is especially suitable for situations where multiple sets of spacing adjustment mechanisms are set, which can significantly reduce the difficulty of operation and improve the convenience of adjustment work.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A rear door opening and closing system of a tank body of a garbage truck, comprising a tank body (1) and a rear door (2), a sealing rubber strip (11) being arranged at a tank opening of the tank body (1), characterized in that: a spacing adjustment mechanism for adjusting the distance between the rear door (2) and the tank body (1) is arranged between the tank body (1) and the rear door (2), the spacing adjustment mechanism comprises a U-shaped adjustment seat (3) arranged on the tank body (1), both side arms of the U-shaped adjustment seat (3) are provided with insertion holes, the insertion holes are coaxially arranged, a threaded rod (41) is inserted into the insertion holes, a threaded adjustment knob (44) is connected to the threaded rod (41), the threaded adjustment knob (44) is located between the two side arms of the U-shaped adjustment seat (3), and one end of the threaded rod (41) is hingedly connected to the rear door (2). A driving mechanism for driving the rear door (2) to open and close is further arranged between the tank body (1) and the rear door (2). A locking mechanism for locking the rear door (2) at the tank opening of the tank body (1) is further arranged between the tank body (1) and the rear door (2). One end of the threaded rod (41) towards the rear door (2) is provided with a connecting portion (42), the connecting portion (42) is provided with a hinge shaft (43), the rear door (2) is provided with a hinge seat (21), and the hinge shaft (43) is rotationally and movably connected to the hinge seat (21).

2. A tank door opening and closing system for a tank of a sanitation truck according to claim 1, characterized in that: The threaded adjustment knob (44) is one, and the length of the threaded adjustment knob (44) is the same as the spacing between the two side arms of the U-shaped adjustment seat (3).

3. The tank door opening and closing system of a tank-type sanitation vehicle according to claim 1, characterized in that: Two threaded adjustment knobs (44) are arranged, the two threaded adjustment knobs (44) are located between the two side arms of the U-shaped adjustment seat (3), and each threaded adjustment knob (44) is in close contact with one side arm of the U-shaped adjustment seat (3).

4. The tank door opening and closing system of a tank-type sanitation vehicle according to claim 1, characterized in that: The driving mechanism comprises a door opening oil cylinder (5), one end of the door opening oil cylinder (5) is hingedly connected to the tank body (1), the other end of the door opening oil cylinder (5) is hingedly connected to the rear door (2), and the door opening oil cylinder (5) is connected to a vehicle-mounted hydraulic oil circuit system through an oil pipe.

5. The tank door opening and closing system of a tank-type sanitation vehicle according to claim 1, characterized in that: The door opening oil cylinder (5) comprises a driving door opening oil cylinder (51) and a driven door opening oil cylinder (52), the driving door opening oil cylinder (51) and the driven door opening oil cylinder (52) are connected in series, and a bidirectional compensation valve (75) is arranged between the vehicle-mounted hydraulic oil circuit system and the driving door opening oil cylinder (51) and the driven door opening oil cylinder (52).

6. A tank door opening and closing system for a tank of a sanitation truck according to claim 5, characterized in that: The locking mechanism comprises a locking oil cylinder (6), a cylinder body end of the locking oil cylinder (6) is fixed to the tank body (1), a piston rod end of the locking oil cylinder (6) is connected to a wedge-shaped locking block (61), a locking tongue (62) corresponding to the wedge-shaped locking block (61) is arranged on the rear door (2), the locking tongue (62) is provided with a locking hole matched with a wedge surface of the wedge-shaped locking block (61), and the locking oil cylinder (6) is connected to the vehicle-mounted hydraulic oil circuit system through an oil pipe.

7. A tank door opening and closing system for a tank of a sanitation truck according to claim 1, characterized in that: ​ 8. A tank door opening and closing system for a tank of a sanitation truck according to claim 1, characterized in that: The outer ring of the screw adjusting knob (44) is arranged in a circular structure, and the outer ring of the screw adjusting knob (44) is uniformly provided with teeth in the circumferential direction; the tank body (1) is slidably provided with a rack (45) engaged with the teeth of the outer ring of the screw adjusting knob (44); the tank body (1) is further rotatably provided with a gear (46) engaged with the rack (45); and the gear (46) is coaxially fixed with a hexagonal head adjusting knob (48) on one side.

9. A tank door opening and closing system for a tank of a sanitation truck according to claim 8, characterized in that: A rotating shaft seat (471) is arranged on the tank body (1), the gear (46) is rotatably connected with the rotating shaft seat (471) through a rotating shaft (461), one end of the rack (45) is fixedly connected with a sliding block (492), a fixing seat (47) is arranged on the tank body (1), a linear guide rail (491) is arranged on the fixing seat (47), and the sliding block (492) is slidably connected with the linear guide rail (491).

10. The tank door opening and closing system of a tank-type sanitation vehicle according to claim 1, characterized in that: The distance adjusting mechanism adopts at least two groups.

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