Palm vehicle hydraulic control system

Abstract

The utility model relates to the technical field of hydraulic control, in particular to a palm vehicle hydraulic control system. The system comprises a main control system and a pilot control system, the main control system comprises a main control valve, a first gear pump and a second gear pump, the first gear pump and the second gear pump are connected to an oil tank, a left loop and a right loop are arranged in the main control valve, and the first gear pump and the second gear pump are connected to the two loops respectively for oil supply; each control link is connected to the working cavity of the corresponding execution element; a double-pump hydraulic system is adopted, seven hydraulic actions of the palm vehicle are uniformly distributed on two hydraulic pumps, the load fatigue of a single-pump system is reduced, the service life of the pumps is prolonged, the faults of the hydraulic pumps are reduced, and the fault-free service time of a user is greatly prolonged; hydraulic actions controlled by the first gear pump and the second gear pump can act simultaneously to complete composite motion, and the defects that a single-pump hydraulic system cannot complete hydraulic composite motion and the working efficiency is reduced are overcome.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control technology, specifically to a hydraulic control system for a palm oil cart. Background Technology

[0002] Palm fruit trucks are specialized vehicles used for palm fruit harvesting, handling, and loading. Their hydraulic control system is a key component for enabling the operation of various onboard actuators. Existing palm fruit truck hydraulic systems mostly adopt a single-pump, single-circuit oil supply structure, which prevents different actuators from performing combined actions. At the same time, in order to control costs, some systems only use a simple on / off pilot control method, which is difficult to meet the requirements for the smoothness of operation and speed adjustability of key actuators (such as boom and stick). Utility Model Content

[0003] The purpose of this utility model is to provide a reasonably designed hydraulic control system for palm oil carts, which addresses the defects and shortcomings of existing technologies and can solve the aforementioned deficiencies.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: It includes a main control system and a pilot control system. The main control system includes a main control valve and gear pump one and gear pump two connected to the oil tank. The main control valve has two circuits, left and right. Gear pump one and gear pump two are respectively connected to the two circuits for oil supply. The main control valve has multiple control links, namely boom control link, bucket control link, grab tension control link, truck bed lifting control link, grab swing control link, stick control link, and turret swing control link. Among them, the boom control link, bucket control link, and grab tension control link are all located in the left circuit, and the remaining control links are located in the right circuit. Each control link is connected to the working chamber of the corresponding actuator.

[0005] The pilot control system includes a pilot hydraulic handle one, a pilot hydraulic handle two, a pilot control valve group, and a pilot gear pump. The pressure output end of the pilot gear pump is connected to the pilot control valve group. Both pilot hydraulic handle one and pilot hydraulic handle two are connected to the hydraulic circuit in the pilot control valve group. The hydraulic circuit in the pilot control valve group is equipped with a pilot main solenoid valve and multiple solenoid directional valves. Pilot hydraulic handle one, pilot hydraulic handle two, and multiple solenoid valves are all connected to the rear of the pilot main solenoid valve. The hydraulic signal output by the pilot control valve group is connected to the pilot chamber of each proportional valve core of the main control valve.

[0006] Preferably, the boom control link is connected to a boom cylinder, the bucket control link is connected to a bucket cylinder, the gripper tension control link is connected to a gripper tension cylinder, the cargo box lifting control link is connected to a cargo box lifting cylinder, the gripper swing control link is connected to a gripper swing motor, the stick control link is connected to a stick cylinder, and the turret swing control link is connected to a turret swing cylinder.

[0007] Preferably, the plurality of electromagnetic reversing valves are, in sequence, a gripper left-turning electromagnetic valve, a gripper right-turning electromagnetic valve, a carriage lowering electromagnetic valve, a carriage raising electromagnetic valve, a gripper tightening electromagnetic valve, and a gripper loosening electromagnetic valve.

[0008] Preferably, a pilot filter is provided at the oil inlet port of the pilot control valve group, and a pilot main relief valve is provided between the outlet of the pilot filter and the return oil circuit in the pilot control valve group.

[0009] Preferably, a one-way valve is connected to the rear end of the pilot filter, and a second one-way valve for providing bypass protection is connected in parallel on the pilot filter.

[0010] Preferably, the left circuit is provided with a left overflow valve, and the right circuit is provided with a right overflow valve.

[0011] Preferably, in the left circuit, buffer valve one and buffer valve two are respectively provided in the two oil circuits connected to the boom cylinder; in the right circuit, buffer valve four and buffer valve five are respectively provided in the two oil circuits connected to the turret slewing cylinder, and buffer valve three is provided in the return oil circuit of the boom cylinder.

[0012] Preferably, a suction filter is connected between gear pump one and the oil tank, a suction filter two is connected between gear pump two and the oil tank, and a suction filter three is provided between the pilot gear pump and the oil tank; a high-pressure filter one is provided behind gear pump one, a high-pressure filter two is connected behind gear pump two, and a high-pressure filter three is connected to the rear end of the pilot gear pump.

[0013] Preferably, a radiator is provided on the return oil line connected to the control link on the main control valve.

[0014] The beneficial effects of this utility model after adopting the above structure are:

[0015] 1. In this utility model, the hydraulic control system of the palm car is a dual-pump hydraulic system, which distributes the seven hydraulic actions of the palm car evenly to two hydraulic pumps, reducing the load fatigue of the single-pump system, extending the service life of the pump, reducing the failure of the hydraulic pump, and greatly extending the user's trouble-free use time.

[0016] 2. In this utility model, gear pump one controls three sets of hydraulic actions: boom, bucket, and gripper tensioning; gear pump two controls four sets of hydraulic actions: truck bed, gripper rotation, stick, and turret. The hydraulic actions controlled by gear pump one and gear pump two can be performed simultaneously to complete compound motion, overcoming the shortcomings of single-pump hydraulic systems that cannot complete hydraulic compound actions and reduce work efficiency.

[0017] 3. In this utility model, a pilot control system is used to control the proportional valve core of the main valve. It can select on / off control or proportional control according to the action requirements of different actuators, which not only ensures the smooth operation of key actions, but also takes into account the control of system cost.

[0018] 4. In this utility model, the system is equipped with a relief valve, a buffer valve and a check valve structure for the main circuit and the pilot circuit, which can realize automatic pressure relief and oil compensation when the actuator moves abnormally or changes rapidly, avoid problems such as suction and impact, and improve the safety and stability of the system.

[0019] 5. In this utility model, the pilot hydraulic handle and the electromagnetic directional valve work together to achieve rapid response and fine adjustment of the actuator's movements. In particular, the key movements such as the boom and bucket have good proportional control capabilities, which significantly improves the comfort of operation.

[0020] 6. In this utility model, the system is equipped with multi-stage filters and radiators to ensure oil cleanliness and temperature control, effectively prevent system contamination and overheating, and improve the service life and overall reliability of hydraulic components. Attached Figure Description

[0021] Figure 1 This is a hydraulic schematic diagram of the main control system in this utility model;

[0022] Figure 2 This is the hydraulic schematic diagram of the main control system for the combined action of the boom cylinder and stick cylinder in this utility model.

[0023] Figure 3 This is a hydraulic schematic diagram of the pilot control system in this utility model;

[0024] Figure 4 This is a schematic diagram of the pilot control system for lowering the boom and rotating the gripper to the left in this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Oil tank; 2. Suction filter; 3. Gear pump I; 4. High-pressure filter I; 5. Radiator; 6. Main control valve; 7. Boom cylinder; 8. Bucket cylinder; 9. Grip cylinder; 10. Cargo box lifting cylinder; 11. Grip swing motor; 12. Stick cylinder; 13. Turret swing cylinder; 14. High-pressure filter II; 15. Gear pump II; 16. Suction filter II;

[0027] 601. Left relief valve; 602. Boom control linkage; 603. Buffer valve one; 604. Buffer valve two; 605. Bucket control linkage; 606. Grab tension control linkage; 607. Cargo box lifting control linkage; 608. Grab swing control linkage; 609. Buffer valve three; 610. Stick control linkage; 611. Buffer valve four; 612. Buffer valve five; 613. Turret swing control linkage; 614. Right relief valve;

[0028] 17. Suction filter three; 18. Pilot gear pump; 19. High-pressure filter three; 20. Pilot control valve assembly; 21. Pilot hydraulic handle one; 22. Pilot hydraulic handle two;

[0029] 2001. Left-hand solenoid valve for gripper; 2002. Right-hand solenoid valve for gripper; 2003. Lowering solenoid valve for cargo compartment; 2004. Raising solenoid valve for cargo compartment; 2005. Tightening solenoid valve for gripper; 2006. Loosening solenoid valve for gripper; 2007. Pilot-operated main solenoid valve; 2008. Pilot-operated main relief valve; 2009. Check valve one; 2010. Pilot filter; 2011. Check valve two. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] like Figure 1 , 3 As shown, it includes a main control system and a pilot control system. The main control system includes a main control valve 6 and gear pump 3 and gear pump 15 connected to the oil tank 1, respectively. The main control valve 6 has a left circuit and a right circuit inside, and gear pump 3 and gear pump 15 provide hydraulic oil to the left and right circuits, respectively. The main control valve 6 has multiple control links, namely boom control link 602, bucket control link 605, grab tension control link 606, cargo box lifting control link 607, grab swing control link 608, stick control link 610, and turret swing control link 613. Among them, boom control link 602, bucket control link 605, and grab tension control link 606 are arranged in the left circuit, and the remaining control links are arranged in the right circuit. Each control link is connected to the working chamber of the corresponding actuator.

[0032] Among them, boom control link 602 is connected to boom cylinder 7, bucket control link 605 is connected to bucket cylinder 8, grab tension control link 606 is connected to grab tension cylinder 9, cargo box lifting control link 607 is connected to cargo box lifting cylinder 10, grab swing control link 608 is connected to grab swing motor 11, stick control link 610 is connected to stick cylinder 12, and turret swing control link 613 is connected to turret swing cylinder 13.

[0033] The pilot control system includes a pilot gear pump 18, a pilot hydraulic handle 1 21, a pilot hydraulic handle 22, and a pilot control valve assembly 20. The pressure output end of the pilot gear pump 18 is connected to the pilot control valve assembly 20. The pilot hydraulic handle 1 21 and the pilot hydraulic handle 22 are connected to the hydraulic circuit in the pilot control valve assembly 20. The pilot control valve assembly 20 is equipped with a pilot main solenoid valve 2007 and multiple solenoid directional valves. The pilot hydraulic handles and multiple solenoid valves are connected to the pilot main solenoid valve. Behind 2007; the hydraulic signal output by the pilot control valve group 20 is connected to the pilot chamber of each proportional valve core in the main control valve 6 to realize the pilot control of each actuator in the main control system; multiple solenoid directional valves include: gripper left-turn solenoid valve 2001, gripper right-turn solenoid valve 2002, car body lowering solenoid valve 2003, car body raising solenoid valve 2004, gripper tightening solenoid valve 2005 and gripper loosening solenoid valve 2006, which respectively control the action direction or state switching of each mechanism;

[0034] In the hydraulic circuit, to ensure the safety and stability of the system operation, a pilot filter 2010 is provided at the oil inlet port of the pilot control valve group 20, a pilot main relief valve 2008 is provided between the outlet of the pilot filter 2010 and the return oil circuit, a check valve 1 2009 is provided at the rear end of the filter, and a check valve 2 2011 for providing bypass protection is provided in parallel on the pilot filter 2010.

[0035] The main control system has a left overflow valve 601 in the left loop and a right overflow valve 614 in the right loop. In the left loop, buffer valve 603 and buffer valve 604 are respectively installed in the two oil circuits connected to the boom cylinder 7. In the right loop, buffer valve 611 and buffer valve 612 are respectively installed in the two oil circuits connected to the turret slewing cylinder 13. Buffer valve 609 is installed in the return oil circuit of the boom cylinder 12 to reduce impact and improve system response stability.

[0036] In addition, to ensure the quality of hydraulic oil, a suction filter 2 is installed between gear pump 3 and oil tank 1, a suction filter 2 16 is installed between gear pump 2 15 and oil tank 1, and a suction filter 3 17 is installed between pilot gear pump 18 and oil tank 1; the outlet of gear pump 3 is connected to high pressure filter 4, the outlet of gear pump 2 15 is connected to high pressure filter 2 14, and the outlet of pilot gear pump 18 is connected to high pressure filter 3 19.

[0037] A radiator 5 is installed on the return oil line of each control link of the main control valve 6 to reduce the temperature of the hydraulic oil and ensure the long-term stable operation of the system.

[0038] In the main control system, the left and right circuits are supplied with oil by gear pump 3 and gear pump 15 respectively, so they can work independently. That is, the actuators driven by them can move simultaneously. For example, the boom cylinder 7 and stick cylinder 12 can move simultaneously, as can the boom cylinder 7 and turret slewing cylinder 13, to achieve compound motion, improve machine operating efficiency, and enhance the operator's experience. Moreover, the various hydraulic actions of the palm truck are distributed evenly to the two gear pumps, reducing the working time and labor intensity of the gear pumps, increasing their lifespan, and extending the fault-free operation time of the hydraulic system. The control methods of each hydraulic actuator are as follows: hydraulic proportional control of boom cylinder 7, hydraulic proportional control of bucket cylinder 8, switch control of grab tension cylinder 9, switch control of truck bed lifting cylinder 10, switch control of grab slewing motor 11, hydraulic proportional control of stick cylinder 12, and hydraulic proportional control of turret slewing cylinder 13.

[0039] See Figure 2 The following explanation uses the combined action of boom cylinder 7 and stick cylinder 12 as an example:

[0040] The pilot chamber b1 of the boom control linkage 602 receives a proportional pressure signal, and the valve opening can be proportionally adjusted, thereby realizing the proportional control of the extension and retraction of the boom cylinder 7. The gear pump 3 draws oil from the hydraulic oil tank 1 through the suction filter 2, and the pressure oil it outputs passes through the high pressure filter 4 and the lower channel of the boom control linkage 602 in sequence, and enters the lower chamber of the boom cylinder 7 to drive the cylinder to extend. At the same time, the return oil from the upper chamber of the boom cylinder 7 flows through the lower channel of the boom control linkage 602, through the radiator 5, and finally returns to the hydraulic oil tank 1. The left overflow valve 601 set in the left circuit is used to control the system pressure and play a safety protection role. The buffer valve 603 and buffer valve 604 set in the oil circuit of the two chambers of the boom cylinder 7 are used to protect the cylinder. When the oil supply to one chamber of the cylinder is insufficient due to excessive movement speed, the one-way valve built into the buffer valve can automatically replenish the oil to prevent the cavitation phenomenon.

[0041] Meanwhile, the valve core pilot chamber b6 of the boom control linkage 610 receives a proportional pressure signal, and its valve core opening can also be proportionally adjusted to realize the proportional control of the extension and retraction of the boom cylinder 12; the gear pump 15 draws oil from the hydraulic oil tank 1 through the suction filter 16, and the pressure oil it outputs passes through the high pressure filter 14 and the lower channel of the boom control linkage 610 in sequence, and enters the lower chamber of the boom cylinder 12 to drive the cylinder to extend; the return oil from the upper chamber of the boom cylinder 12 flows through the lower channel of the boom control linkage 610, through the radiator 5, and finally returns to the hydraulic oil tank 1;

[0042] Through the above control method, the boom cylinder 7 and stick cylinder 12 can be operated simultaneously, and their pressure and flow do not interfere with each other during operation, thus enabling the palm crane mechanism to complete compound actions.

[0043] The pilot control system provides pilot control pressure to the main control valve 6. The pilot pressure signal is divided into two categories: the first category is the on / off hydraulic signal. The main control valve 6 core controlled by this type of signal has three fixed positions: upper, middle and lower. This meets the control requirements of the palm truck hydraulic actuator for simple on / off actions and achieves the expected function under the premise of being economical and practical. The three actions of the palm truck's lifting and lowering of the truck bed, tightening and loosening of the grab handle, and rotating of the grab handle are all controlled by the on / off hydraulic signal. The corresponding solenoid directional valves include: grab handle left-turn solenoid valve 2001, grab handle right-turn solenoid valve 2002, truck bed lowering solenoid valve 2003, truck bed raising solenoid valve 2004, grab handle tightening solenoid valve 2005, and grab handle loosening solenoid valve 2006.

[0044] The second type is hydraulic proportional control signal. The four sets of actions of boom, bucket, stick, and turret swing have an important impact on the comfort of the vehicle's operation and the smoothness of its operation. Therefore, hydraulic proportional control signal is adopted. The proportional valve cores in boom control link 602, bucket control link 605, stick control link 610, and turret swing control link 613 can be adjusted proportionally with the pilot pressure to realize the proportional control of the actuator.

[0045] Pilot hydraulic handle 21 is used to control the boom and bucket movements. This handle can move in four directions: forward, backward, left, and right, corresponding to four proportional movements. The pressure signal output by the handle is proportional to its movement angle. Therefore, the pressure in the corresponding valve core pilot chamber in the main control valve 6 can also be adjusted proportionally to achieve controllable ratio between valve core opening and actuator speed. Pilot hydraulic handle 22 works similarly.

[0046] See Figure 2 Taking the boom descent and the grab's leftward rotation as examples, the basic working principle of the pilot oil circuit is explained:

[0047] First, after the pilot main solenoid valve 2007 is energized, it switches to the right position. The pilot gear pump 18 draws oil from the oil tank 1 through the suction filter 17. Its output pressure oil flows sequentially through the high pressure filter 19, the pilot filter 2010, and the check valve 2009, and then through the switched pilot main solenoid valve 2007 to enter the grab handle left-hand solenoid valve 2001 or output a pressure signal from the pilot hydraulic handle. The pilot main relief valve 2008 in the system is used to limit the pilot system pressure and play a protective role. When the grab handle left-hand solenoid valve 2001 is energized, the pilot chamber of the grab handle rotation control link 608 in the main control valve 6 receives a hydraulic signal and drives the grab handle rotation motor 11 to achieve a left-hand rotation action. At the same time, when the pilot hydraulic handle is moved forward, the corresponding pilot chamber in the boom control link 602 receives a proportional pressure signal, thereby controlling the boom cylinder 7 to achieve a lowering action.

[0048] It should be understood that the above-described specific embodiments of this utility model are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within the protection scope of this utility model. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A hydraulic control system for a palm car, comprising a main control system and a pilot control system, characterized in that: The main control system comprises a main control valve (6) and gear pumps (3) and (15) connected to the oil tank (1), the main control valve (6) is provided with left and right two circuits, the gear pumps (3) and (15) are connected to the two circuits respectively for oil supply, the main control valve (6) is provided with a plurality of control links, which are boom control link (602), bucket control link (605), grabber tension control link (606), carriage lifting control link (607), grabber rotation control link (608), arm control link (610) and turning rotation control link (613), wherein the boom control link (602), the bucket control link (605) and the grabber tension control link (606) are arranged in the left circuit, and the remaining control links are arranged in the right circuit; each control link is connected to the working cavity of the corresponding execution element. The pilot control system comprises a pilot hydraulic handle (21), a pilot hydraulic handle (22), a pilot control valve group (20) and a pilot gear pump (18), the pressure output end of the pilot gear pump (18) is connected to the pilot control valve group (20), the pilot hydraulic handle (21) and the pilot hydraulic handle (22) are connected with the hydraulic circuit in the pilot control valve group (20), the hydraulic circuit in the pilot control valve group (20) is provided with a pilot main electromagnetic valve (2007) and a plurality of electromagnetic directional valves, the pilot hydraulic handle (21) and the pilot hydraulic handle (22) and the plurality of electromagnetic valves are connected behind the pilot main electromagnetic valve (2007); the hydraulic signal output by the pilot control valve group (20) is connected to the pilot cavity of each proportional valve core of the main control valve (6).

2. A hydraulic control system for a palm car according to claim 1, wherein: The boom control link (602) is connected with a boom oil cylinder (7), the bucket control link (605) is connected with a bucket oil cylinder (8), the grabber tension control link (606) is connected with a grabber tension oil cylinder (9), the carriage lifting control link (607) is connected with a carriage lifting oil cylinder (10), the grabber rotation control link (608) is connected with a grabber rotation motor (11), the arm control link (610) is connected with an arm oil cylinder (12), and the turning rotation control link (613) is connected with a turning rotation oil cylinder (13).

3. A hydraulic control system for a palm car according to claim 1, wherein: The plurality of electromagnetic directional valves are in sequence a grabber left rotation electromagnetic valve (2001), a grabber right rotation electromagnetic valve (2002), a carriage descending electromagnetic valve (2003), a carriage ascending electromagnetic valve (2004), a grabber tightening electromagnetic valve (2005) and a grabber loosening electromagnetic valve (2006).

4. A hydraulic control system for a palm car according to claim 1, wherein: The pilot control valve group (20) is provided with a pilot filter (2010) at an oil inlet port, a pilot main overflow valve (2008) is arranged between the outlet of the pilot filter (2010) and the oil return path in the pilot control valve group (20).

5. A hydraulic control system for a palm car according to claim 4, wherein: The pilot filter (2010) is connected with a one-way valve (2009) at the rear end, and a one-way valve (2011) for providing bypass protection is connected in parallel to the pilot filter (2010).

6. A hydraulic control system for a palm car according to claim 1, wherein: The left circuit is provided with a left overflow valve (601), and the right circuit is provided with a right overflow valve (614).

7. A hydraulic control system for a palm car according to claim 2, wherein: The left circuit is connected with the boom cylinder (7), and the two oil paths are respectively provided with buffer valve one (603) and buffer valve two (604); the right circuit is connected with the swing cylinder (13), and the two oil paths are respectively provided with buffer valve four (611) and buffer valve five (612), and the oil return path of the arm cylinder (12) is provided with buffer valve three (609).

8. A hydraulic control system for a palm car according to claim 1, wherein: The gear pump one (3) is connected with the oil tank (1) and connected with the oil suction filter (2), the gear pump two (15) is connected with the oil tank (1) and connected with the oil suction filter two (16), and the pilot gear pump (18) is provided with the oil suction filter three (17) between the oil tank (1); the rear of the gear pump one (3) is provided with the high pressure filter one (4), the rear of the gear pump two (15) is connected with the high pressure filter two (14), and the rear end of the pilot gear pump (18) is connected with the high pressure filter three (19).

9. A hydraulic control system for a palm car according to claim 1, wherein: The main control valve (6) is connected with the oil return path, and the oil return path is provided with the radiator (5).

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