Working device, loader and working device control method

Abstract

The present invention belongs to the technical field of engineering machinery, and discloses a working device, a loader, and a working device control method. A working bucket, a lifting mechanism, a bucket transfer mechanism, and a hydraulic drive system. The working bucket can shovel materials; the lifting mechanism can lift the working bucket; and the bucket transfer mechanism can drive the working bucket to rotate. The hydraulic drive system includes an oil tank, a lifting drive subsystem, and a bucket transfer drive subsystem. The bucket transfer drive subsystem and the lifting drive subsystem can respectively increase the pressure of the oil to form hydraulic oil, which is supplied to the lifting mechanism and the bucket transfer hydraulic cylinder. The lifting drive subsystem includes a lifting hydraulic pump and an accumulator, which can supply hydraulic oil to the lifting mechanism respectively. The priority of the accumulator oil supply process is higher than the priority of the lifting hydraulic pump oil supply process. The working device can reduce the overflow loss of hydraulic oil during operation, reasonably utilize hydraulic oil and energy, and reduce energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a working device, a loader and a working device control method. Background Art

[0002] A loader is a type of earthmoving machinery widely used in construction projects such as highways, railways, buildings, hydropower stations, ports, and mines. It is primarily used for loading bulk materials such as soil, sand, gravel, lime, and coal, and can also perform light excavation of ore and hard soil. The loader's working mechanism performs the primary operations within the loader, including loading, lifting, and lowering.

[0003] Existing drive systems for loader working devices primarily rely on valve-controlled hydraulic systems. These systems suffer from significant throttling losses during use, leading to the increasing adoption of pump-controlled drive systems in loaders. However, existing pump-controlled drive systems suffer from high costs for asymmetric pumps and inadequate compatibility with accumulators, making it difficult to effectively combine energy consumption reduction with efficiency improvement.

[0004] Therefore, there is an urgent need for a working device, a loader and a working device control method to solve the above problems. Summary of the Invention

[0005] According to one aspect of the present invention, an object is to provide a working device that can reduce hydraulic oil overflow losses during operation, rationally utilize hydraulic oil and energy, and reduce energy consumption.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] Working device, including:

[0008] A working bucket configured to shovel and load materials;

[0009] a lifting mechanism connected to the working bucket and configured to lift the working bucket;

[0010] The bucket rotating mechanism includes a bucket rotating hydraulic cylinder and a bucket rotating cylinder rod. Both ends of the bucket rotating cylinder rod can extend out of the bucket rotating hydraulic cylinder and are coaxially movably arranged in the bucket rotating hydraulic cylinder. One end of the bucket rotating cylinder rod is transmission-connected to the working bucket. The bucket rotating cylinder rod moves along the axial direction of the bucket rotating hydraulic cylinder to drive the working bucket to rotate.

[0011] A hydraulic drive system comprising an oil tank and a lifting drive subsystem and a bucket drive subsystem respectively connected to the oil tank, wherein the oil tank is capable of providing oil to the bucket drive subsystem and the lifting drive subsystem, and the bucket drive subsystem and the lifting drive subsystem are capable of respectively increasing the pressure of the oil to form hydraulic oil, which is supplied to the lifting mechanism and the bucket hydraulic cylinder;

[0012] The lifting drive subsystem includes a lifting hydraulic pump and an accumulator. The lifting hydraulic pump is arranged between the oil tank and the lifting mechanism and can absorb oil from the oil tank and increase the pressure of the oil to form hydraulic oil. The accumulator can store excess hydraulic oil discharged by the lifting hydraulic pump and supply it to the lifting mechanism.

[0013] The priority of the process of the accumulator supplying oil to the lifting mechanism is higher than the priority of the process of the lifting hydraulic pump supplying oil to the lifting mechanism.

[0014] As a preferred solution of the working device provided by the present invention, the bucket driving subsystem includes a bucket hydraulic pump, which is connected to the oil tank and can absorb oil in the oil tank;

[0015] The bucket hydraulic pump includes a first oil discharge port and a second oil discharge port respectively connected to the two bucket rod chambers of the bucket hydraulic cylinder. The bucket hydraulic pump can provide hydraulic oil to the two bucket rod chambers through the first oil discharge port and the second oil discharge port.

[0016] As a preferred solution of the working device provided by the present invention, the bucket drive subsystem further includes at least two first overflow valves;

[0017] The first overflow valve is provided between the first bucket oil passage between the first oil discharge port and one of the bucket rod chambers and the oil tank;

[0018] The first overflow valve is provided between the second bucket oil passage between the second oil discharge port and the other bucket rod cavity and the oil tank;

[0019] The hydraulic oil in the first bucket oil circuit and the second bucket oil circuit can flow back to the oil tank through the first overflow valve respectively.

[0020] As a preferred solution of the working device provided by the present invention, the hydraulic drive system also includes an oil replenishment subsystem, and the oil replenishment subsystem includes an oil replenishment hydraulic pump. The oil replenishment hydraulic pump is connected to the oil tank and can pump the oil in the oil tank to the lifting mechanism, and can also pump the oil in the oil tank to the bucket hydraulic cylinder.

[0021] As a preferred solution of the working device provided by the present invention, the oil replenishment subsystem also includes an oil replenishment motor, which is connected to the oil replenishment hydraulic pump and can drive the oil replenishment hydraulic pump to work; the speed of the oil replenishment motor can be adjusted to control the intermittent start-up of the oil replenishment hydraulic pump.

[0022] As a preferred solution of the working device provided by the present invention, the oil replenishment subsystem also includes a first one-way valve and a second one-way valve, and the first one-way valve and the second one-way valve are respectively arranged between the oil replenishment hydraulic pump and the oil supply circuit connected to the bucket hydraulic cylinder, and are configured to prevent the hydraulic oil in the oil supply circuit from flowing back into the oil tank.

[0023] As a preferred solution of the working device provided by the present invention, the oil replenishment subsystem also includes a second overflow valve, which is arranged between the oil replenishment hydraulic pump and the oil tank and is configured to guide excess hydraulic oil discharged by the oil replenishment hydraulic pump to the oil tank.

[0024] As a preferred solution of the working device provided by the present invention, the lifting drive subsystem also includes a third one-way valve, which is arranged between the oil tank and the accumulator and is configured to prevent the hydraulic oil in the accumulator from flowing into the oil tank.

[0025] As a preferred embodiment of the working device provided by the present invention, the working device further comprises a movable arm and a fixed bracket, the movable arm is rotatably connected to the fixed bracket, and the working bucket is rotatably connected to the movable arm; and / or,

[0026] The bucket turning mechanism also includes a movably connected rocker arm and a connecting rod, the rocker arm is rotatably connected to the movable arm, the connecting rod is rotatably connected to the working bucket, one end of the bucket turning cylinder rod is movably connected to the rocker arm, and the other end is movably connected to the fixed bracket.

[0027] As a preferred solution of the working device provided by the present invention, the lifting mechanism includes a lifting hydraulic cylinder and a lifting cylinder rod, the lifting hydraulic cylinder is movably connected to the fixed bracket, the lifting cylinder rod is coaxially and movably arranged in the lifting hydraulic cylinder, and one end of the lifting cylinder rod extending out of the lifting hydraulic cylinder is movably connected to the boom.

[0028] As a preferred solution of the working device provided by the present invention, the lifting drive subsystem further includes two third overflow valves;

[0029] The lifting hydraulic pump is connected to the lifting rod chamber of the lifting hydraulic cylinder through a first lifting oil passage; the lifting hydraulic pump is connected to the lifting rodless chamber of the lifting hydraulic cylinder through a second lifting oil passage;

[0030] The two third relief valves are disposed in parallel and opposite to each other between the first lifting oil circuit and the second lifting oil circuit, and the hydraulic oil between the first lifting oil circuit and the second lifting oil circuit can flow through the two third relief valves.

[0031] According to another aspect of the present invention, the object is to provide a loader, which includes a cab body, a transfer device and a working device as described in any one of the above schemes, the transfer device is arranged on the cab body and is configured to drive the cab body to move, and the working device is arranged on the cab body.

[0032] According to another aspect of the present invention, an object is to provide a working device control method, wherein the working device control method is performed based on the working device according to any one of the above solutions;

[0033] The bucket driving subsystem includes a bucket hydraulic pump and a bucket motor, and the bucket motor drives the bucket hydraulic pump to work;

[0034] The lifting drive subsystem includes a lifting hydraulic pump and a lifting motor, wherein the lifting motor drives the lifting hydraulic pump to work, and the lifting mechanism includes a lifting hydraulic cylinder and a lifting cylinder rod, wherein the lifting cylinder rod is coaxially and movably arranged in the lifting hydraulic cylinder;

[0035] The working device control method includes:

[0036] S10, obtaining a displacement error of the bucket hydraulic cylinder, where the displacement of the bucket hydraulic cylinder is a displacement distance of the bucket cylinder rod relative to the bucket hydraulic cylinder;

[0037] S20, calculating a bucket speed adjustment amount of the bucket motor according to a displacement error of the bucket hydraulic cylinder;

[0038] S30, determining the bucket oil replenishment action based on the relationship between the bucket speed adjustment amount and the bucket speed adjustment threshold; if the bucket speed adjustment amount is less than or equal to the bucket speed adjustment threshold, proceed to S40 and S50 in sequence; otherwise, proceed to S60;

[0039] S40, obtaining a bucket speed correction value of the bucket motor;

[0040] S50, obtaining a corrected actual displacement of the bucket of the bucket hydraulic cylinder when the bucket motor operates at the corrected bucket speed value;

[0041] S60, replenishing oil to the bucket drive subsystem according to the bucket speed adjustment amount;

[0042] S70: Acquire a displacement error of the lifting hydraulic cylinder, where the displacement of the lifting hydraulic cylinder is a displacement distance of the lifting cylinder rod relative to the lifting hydraulic cylinder;

[0043] S80, identifying the working state of the accumulator, and when the actual flow rate of the accumulator is greater than the flow rate threshold, selecting a conversion factor of 0.5; otherwise, selecting a conversion factor of 0.9;

[0044] S90, calculating a lifting speed adjustment amount of the lifting motor according to the conversion factor;

[0045] S100, determining a lifting oil replenishment action based on the relationship between the lifting speed adjustment amount and the lifting speed adjustment threshold; if the lifting speed adjustment amount is less than or equal to the lifting speed adjustment threshold, proceed to steps S110 and S120 in sequence; otherwise, proceed to S130;

[0046] S110, obtaining a lifting speed correction value of the lifting motor;

[0047] S120, obtaining a lifting corrected actual displacement of the lifting hydraulic cylinder when the lifting motor operates at the lifting speed correction value;

[0048] S130 , replenishing oil to the lifting drive subsystem according to the lifting speed adjustment amount.

[0049] Beneficial effects of the present invention:

[0050] The working device provided by the present invention includes a working bucket, a lifting mechanism, a bucket turning mechanism and a hydraulic drive system. The working bucket is configured to shovel materials. The lifting mechanism is connected to the working bucket and is configured to lift the working bucket. The bucket turning mechanism includes a bucket turning hydraulic cylinder and a bucket turning cylinder rod. The two ends of the bucket turning cylinder rod can respectively extend out of the bucket turning hydraulic cylinder and are coaxially movably arranged in the bucket turning hydraulic cylinder. One end of the bucket turning cylinder rod is transmission-connected to the working bucket. The bucket turning cylinder rod moves axially along the bucket turning hydraulic cylinder to drive the working bucket to rotate. By adopting the above-mentioned arrangement in which both ends of the bucket turning cylinder rod can extend out of the bucket turning hydraulic cylinder, the problem of unbalanced hydraulic oil flow when a single-rod hydraulic cylinder is used to drive the bucket turning mechanism in the prior art can be solved, thereby effectively reducing overflow losses. The hydraulic drive system includes an oil tank and a lift drive subsystem and a bucket drive subsystem, each connected to the oil tank. The oil tank supplies oil to the bucket drive subsystem and the lift drive subsystem. The bucket drive subsystem and the lift drive subsystem each increase the oil pressure to form hydraulic oil, which is then supplied to the lifting mechanism and the bucket hydraulic cylinder. The lift drive subsystem and the bucket drive subsystem respectively drive the lifting mechanism and the bucket mechanism. The lift drive subsystem includes a lift hydraulic pump and an accumulator. The lift hydraulic pump is located between the oil tank and the lifting mechanism and draws oil from the oil tank, increasing the oil pressure to form hydraulic oil. The accumulator stores excess hydraulic oil discharged by the lift hydraulic pump and supplies it to the lifting mechanism. This arrangement allows the accumulator to recover gravitational potential energy accumulated during operation of the working device, achieving efficient utilization of hydraulic oil flow and energy. The accumulator's oil supply to the lifting mechanism takes precedence over the lift hydraulic pump's oil supply to the lifting mechanism. This arrangement prioritizes the use of the high-pressure, high-energy hydraulic oil stored in the accumulator during lifting of the working device. When the accumulator's hydraulic oil flow rate is low, the lift hydraulic pump serves as the primary power source for lifting the working device. This arrangement fully utilizes the accumulator's stored gravitational potential energy, reduces the lift hydraulic pump's energy consumption, and mitigates the impact of the accumulator's high-pressure oil on the working device's lifting motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a structural schematic diagram of a loader provided by an embodiment of the present invention;

[0052] Figure 2 It is a partial structural diagram of a loader provided by an embodiment of the present invention;

[0053] Figure 3 It is a partial schematic diagram of a working device provided by an embodiment of the present invention.

[0054] In the picture:

[0055] 10. Cab body; 20. Transfer device;

[0056] 100. Work bucket;

[0057] 200, lifting mechanism; 210, lifting hydraulic cylinder; 211, lifting rod chamber; 212, lifting rodless chamber; 220, lifting cylinder rod; 221, lifting connection end;

[0058] 300, bucket mechanism; 310, bucket hydraulic cylinder; 311, bucket rod chamber; 320, bucket cylinder rod; 321, bucket connecting end; 330, rocker arm; 331, rocker arm hinge end; 340, connecting rod;

[0059] 400, hydraulic drive system; 410, fuel tank;

[0060] 420, lift drive subsystem; 421, lift hydraulic pump; 4211, third oil drain port; 4212, fourth oil drain port; 4213, fifth oil drain port; 422, accumulator; 423, third check valve; 424, third relief valve; 425, lift motor;

[0061] 430, bucket drive subsystem; 431, bucket hydraulic pump; 432, first relief valve; 433, bucket motor; 440, oil replenishment subsystem; 441, oil replenishment hydraulic pump; 442, oil replenishment motor; 443, first one-way valve; 444, second one-way valve; 445, second relief valve;

[0062] 500, boom; 510, boom hinge end;

[0063] 600, fixed bracket; 610, first upper connecting member; 620, lower connecting member; 630, second upper connecting member. DETAILED DESCRIPTION

[0064] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0065] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0066] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0067] In the description of this embodiment, terms such as "upper," "lower," "right," and "left" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0068] Figure 1 A schematic structural diagram of a loader provided by an embodiment of the present invention is shown; Figure 2 A partial structural schematic diagram of a loader provided by an embodiment of the present invention is shown; Figure 3 A partial schematic diagram of a working device provided by an embodiment of the present invention is shown. Figure 1-Figure 3 , this embodiment provides a working device and a loader.

[0069] The loader includes a cab body 10, a transfer device 20, and a working device provided in this embodiment. The transfer device 20 is disposed at the bottom of the cab body 10 and is configured to drive the cab body 10 to move. The working device is disposed at the front end of the cab body 10 and is configured to shovel, lift, and transfer materials.

[0070] Specifically, the working device includes a working bucket 100, a lifting mechanism 200, a bucket rotating mechanism 300, a hydraulic drive system 400, and a fixed bracket 600. The fixed bracket 600 is arranged at the front end of the cab body 10 and serves as an installation reference for the working bucket 100, the lifting mechanism 200, and the bucket rotating mechanism 300. The working bucket 100 is configured to shovel materials. The lifting mechanism 200 is connected between the working bucket 100 and the fixed bracket 600 and is configured to lift the working bucket 100. The bucket rotating mechanism 300 is connected between the working bucket 100 and the fixed bracket 600 and is configured to rotate the working bucket 100. The hydraulic drive system 400 is configured to drive the lifting mechanism 200 and the bucket rotating mechanism 300 to operate.

[0071] Reference Figure 1-Figure 3The bucket mechanism 300 includes a bucket hydraulic cylinder 310, a bucket cylinder rod 320, a rocker arm 330, and a connecting rod 340, which are rotatably connected to each other. The connecting rod 340 is rotatably connected to the rocker arm hinge end 331 of the rocker arm 330. Both ends of the bucket cylinder rod 320 can extend out of the bucket hydraulic cylinder 310 and are coaxially movably disposed in the bucket hydraulic cylinder 310. One end of the bucket cylinder rod 320 is a bucket connecting end 321, which is rotatably connected to the rocker arm 330 and is transmission-connected to the working bucket 100 through the rocker arm 330 and the connecting rod 340. The connecting rod 340 is rotatably connected to the working bucket 100 in an articulated manner. The other end of the bucket cylinder rod 320 is movably connected to the first upper connecting member 610 on the fixed bracket 600 in an articulated manner. The bucket cylinder rod 320 moves along the axial direction of the bucket hydraulic cylinder tube 310, which can drive the rocker arm 330 and the connecting rod 340 to rotate, and further drive the working bucket 100 to rotate.

[0072] Specifically, the bucket rotating mechanisms 300 are arranged in pairs and move synchronously, which can ensure the support performance of the working bucket 100 and ensure the stability and reliability of the working bucket 100 when rotating.

[0073] Continue to refer to Figure 1-Figure 3 The working device further includes a movable arm 500. The movable arm 500 is rotatably connected to the fixed bracket 600 via a second upper connecting member 630, and the working bucket 100 is rotatably connected to an end of the movable arm 500 away from the fixed bracket 600. The rocker arm 330 is rotatably connected to the side of the movable arm 500.

[0074] Continue to refer to Figure 1-Figure 3 The lifting mechanism 200 includes a lifting hydraulic cylinder 210 and a lifting cylinder rod 220. The lifting hydraulic cylinder 210 is movably connected to the lower connecting member 620 of the fixed bracket 600. The lifting cylinder rod 220 is coaxially and movably disposed in the lifting hydraulic cylinder 210. The lifting connection end 221 of the lifting cylinder rod 220 extends out of the lifting hydraulic cylinder 210 and is rotatably connected to the side of the boom 500 through the boom hinge end 510.

[0075] Specifically, the lifting mechanisms 200 are arranged in pairs and move synchronously, which can ensure the support performance of the working bucket 100 and ensure the stability and reliability of the working bucket 100 when it is lifted or lowered.

[0076] Reference Figure 3The hydraulic drive system 400 includes an oil tank 410, an oil replenishment subsystem 440, and a lift drive subsystem 420 and a bucket drive subsystem 430, each of which is connected to the oil tank 410. The oil tank 410 can provide oil to the bucket drive subsystem 430 and the lift drive subsystem 420. The bucket drive subsystem 430 and the lift drive subsystem 420 can each increase the pressure of the oil to form hydraulic oil, which is then supplied to the lifting mechanism 200 and the bucket hydraulic cylinder 310. The oil replenishment subsystem 440 is configured to replenish oil to the lift drive subsystem 420 and the bucket drive subsystem 430.

[0077] Specifically, the bucket drive subsystem 430 includes a bucket hydraulic pump 431 and a bucket motor 433. The bucket hydraulic pump 431 is connected to the oil tank 410 and can draw oil from the oil tank 410. The bucket motor 433 is connected to the bucket hydraulic pump 431 and can drive the bucket hydraulic pump 431 to operate. The bucket hydraulic pump 431 includes a first oil drain port and a second oil drain port, each of which is connected to the two bucket rod chambers 311 of the bucket hydraulic cylinder 310. The bucket hydraulic pump 431 can supply hydraulic oil to the two bucket rod chambers 311 through the first and second oil drain ports.

[0078] More specifically, the bucket drive subsystem 430 also includes at least two first relief valves 432. A first relief valve 432 is provided between the first bucket oil circuit, between the first oil drain port and one bucket rod cavity 311, and the oil tank 410. A first relief valve 432 is provided between the second bucket oil circuit, between the second oil drain port and the other bucket rod cavity 311, and the oil tank 410. Hydraulic oil in the first and second bucket oil circuits can flow back to the oil tank 410 through the first relief valves 432, respectively.

[0079] Continue to refer to Figure 3 The lifting drive subsystem 420 includes a lifting hydraulic pump 421 and a lifting motor 425. The lifting motor 425 drives the lifting hydraulic pump 421. The lifting hydraulic pump 421 is arranged between the oil tank 410 and the lifting mechanism 200, and can absorb oil from the oil tank 410, increase the oil pressure, and form hydraulic oil.

[0080] More specifically, the lift hydraulic pump 421 is equipped with three oil discharge ports: a third oil discharge port 4211, a fourth oil discharge port 4212, and a fifth oil discharge port 4213. The third oil discharge port 4211 communicates with the lift rod chamber 211 of the lift hydraulic cylinder 210 via a first lift oil circuit; the fourth oil discharge port 4212 communicates with the lift rodless chamber 212 of the lift hydraulic cylinder 210 via a second lift oil circuit. It should be noted that the sizes of the third and fourth oil discharge ports 4211, 4212 are proportional to the effective axial cross-sectional areas of the lift rod chamber 211 and the lift rodless chamber 212.

[0081] More specifically, the lift drive subsystem 420 also includes an accumulator 422. The accumulator 422 is capable of storing excess hydraulic oil discharged by the lift hydraulic pump 421 and supplying it to the lift mechanism 200. The accumulator 422 is specifically connected to the third oil discharge port 4211. The accumulator 422 has a higher priority in supplying oil to the lift mechanism 200 than the lift hydraulic pump 421. This arrangement allows the high-pressure, high-energy hydraulic oil stored in the accumulator 422 to be used for driving the lifting operation of the working device. When the flow rate of the hydraulic oil in the accumulator 422 is low, the lift hydraulic pump 421 serves as the primary power source for lifting the working device. This arrangement fully utilizes the gravitational potential energy stored in the accumulator 422, reduces the energy consumption of the lift hydraulic pump 421, and mitigates the impact of the high-pressure oil in the accumulator 422 on the lifting operation of the working device. In this embodiment, the accumulator 422 may be a bladder-type accumulator.

[0082] More specifically, the accumulator 422 is selected based on the maximum and minimum pressures of the lifting rodless chamber 212 of the lifting hydraulic cylinder 210. The capacity is calculated as follows:

[0083]

[0084] 0.9p2≤p0<p2,

[0085] Among them, V0 is the inflation volume; ΔV is the volume of oil required to be released during operation, which is generally a known empirical value; p0 is the pre-charge pressure; p1 is the maximum pressure during operation, which can be obtained based on experience and the data of the lifting hydraulic cylinder 210; p2 is the minimum pressure during operation, which can also be obtained based on experience and the data of the lifting hydraulic cylinder 210; n is a variable index, whose value is determined by the working conditions of the gas, and n = 1.25 is generally recommended.

[0086] Preferably, the lifting drive subsystem 420 further includes a third one-way valve 423 , which is disposed between the oil tank 410 and the accumulator 422 and is configured to prevent the hydraulic oil in the accumulator 422 from flowing into the oil tank 410 .

[0087] Preferably, the lift drive subsystem 420 further includes two third relief valves 424. These third relief valves 424 are disposed in parallel, opposite each other, between the first and second lift oil circuits. Hydraulic oil can flow between the first and second lift oil circuits via the two third relief valves 424. This arrangement balances the amount of hydraulic oil in the first and second lift oil circuits.

[0088] Continue to refer to Figure 3The oil replenishment subsystem 440 includes an oil replenishment hydraulic pump 441, which is connected to the oil tank 410. The oil replenishment hydraulic pump 441 can pump oil from the oil tank 410 into the oil circuit between the bucket hydraulic cylinder 310 and the bucket hydraulic pump 431, and then supply it to the bucket hydraulic cylinder 310. The oil replenishment hydraulic pump 441 can also pump oil from the oil tank 410 into the oil circuit between the lifting mechanism 200 and the lifting hydraulic pump 421, and then supply it to the lifting hydraulic pump 421. After being pressurized by the lifting hydraulic pump 421, the hydraulic oil is supplied to the lifting hydraulic cylinder 210 through the third oil discharge port 4211 and the fourth oil discharge port 4212. It should be noted that during the oil replenishment process, the fifth oil discharge port 4213 can serve as the oil inlet of the lifting hydraulic pump 421.

[0089] Specifically, the oil replenishment subsystem 440 also includes an oil replenishment motor 442. This motor is connected to the oil replenishment hydraulic pump 441 and is capable of driving the oil replenishment hydraulic pump 441. The speed of the oil replenishment motor 442 is adjustable to control the intermittent activation of the oil replenishment hydraulic pump 441. This configuration eliminates overflow losses caused by long-term continuous operation of the oil replenishment subsystem 440 in the hydraulic drive system 400, further reducing the energy consumption of the hydraulic drive system 400.

[0090] More specifically, the oil replenishment subsystem 440 also includes a first one-way valve 443 and a second one-way valve 444. The first one-way valve 443 and the second one-way valve 444 are respectively disposed between the oil replenishment hydraulic pump 441 and the oil supply line connecting to the bucket hydraulic cylinder 310. Specifically, the first one-way valve 443 is disposed in the oil line connecting the oil replenishment hydraulic pump 441 and the first bucket oil line, while the second one-way valve 444 is disposed in the oil line connecting the oil replenishment hydraulic pump 441 and the second bucket oil line. The first one-way valve 443 is configured to prevent the hydraulic oil in the first bucket oil line from flowing back into the oil tank 410, while the second one-way valve 444 is configured to prevent the hydraulic oil in the second bucket oil line from flowing back into the oil tank 410.

[0091] More specifically, the oil replenishment subsystem 440 further includes a second relief valve 445. The second relief valve 445 is disposed between the oil replenishment hydraulic pump 441 and the oil tank 410 and is configured to guide excess hydraulic oil discharged from the oil replenishment hydraulic pump 441 to the oil tank 410 for backflow.

[0092] This embodiment also provides a working device control method. The working device control method is performed based on the working device provided in this embodiment. The working device control method specifically includes the following steps:

[0093] S10 . Obtain a displacement error of the bucket hydraulic cylinder 310 . The displacement of the bucket hydraulic cylinder 310 is a displacement distance of the bucket cylinder rod 320 relative to the bucket hydraulic cylinder 310 .

[0094] Specifically, the actual displacement of the bucket hydraulic cylinder 310 is obtained by the bucket displacement sensor integrated on the bucket hydraulic cylinder 310, and the theoretical displacement of the bucket hydraulic cylinder 310 is obtained by the bucket mechanism model. Displacement error = actual displacement - theoretical displacement.

[0095] Specifically, step S10 includes the following steps:

[0096] S11. Obtain the flow rate of the bucket hydraulic pump 431. The theoretical bucket speed of the bucket motor 433 is obtained using the bucket speed sensor integrated into the bucket motor 433. The flow rate of the bucket hydraulic pump 431 is equal to the product of the theoretical bucket speed of the bucket motor 433 and the displacement of the bucket hydraulic pump 431. The displacement of the bucket hydraulic pump 431 is known data.

[0097] S12, then calculate and obtain the theoretical displacement of the bucket hydraulic cylinder 310, and the calculation method is as follows:

[0098]

[0099] Among them, s zl (t i ) is the theoretical displacement of the bucket hydraulic cylinder 310; q zdl (t i ) is the flow rate of the bucket hydraulic pump 431; n zl (t i ) is the theoretical rotation speed of the bucket motor 433; V zd is the displacement of the bucket hydraulic pump 431; A1 is the effective axial cross-sectional area of ​​the bucket rod cavity 311 of the bucket hydraulic cylinder 310; f zdwy1 (·) is the bucket rotation mechanism model, which is known.

[0100] S20 , calculating the bucket speed adjustment amount of the bucket motor 433 according to the displacement error of the bucket hydraulic cylinder 310 .

[0101] Specifically, the speed adjustment value of the bucket motor 433 is obtained according to the bucket feedback control law of the feedback controller in the bucket drive subsystem 430, and the calculation formula is as follows:

[0102] Δn zl (t i )=f zdzs (e szd (t i )),

[0103] Where Δn zl (t i ) = is the bucket speed adjustment amount; f zdzs (·) is the feedback control law of the bucket of the feedback controller, which can be obtained according to the corresponding feedback control algorithm and is known; (e szd (t i)) is the displacement error of the bucket hydraulic cylinder 310.

[0104] S30. Determine the bucket oil replenishment action based on the relationship between the bucket speed adjustment amount and the bucket speed adjustment threshold. If the bucket speed adjustment amount is ≤ the bucket speed adjustment threshold, proceed to S40 and S50 in sequence; otherwise, proceed to S60. The above-mentioned bucket speed adjustment threshold can be flexibly set according to the actual working accuracy requirements.

[0105] S40, obtaining a rotation speed correction value of the bucket motor 433, specifically using the following formula:

[0106] n zdxz (t i )=n zl (t i )+Δn zl (t i ),

[0107] Among them, n zdxz (t i ) = the bucket speed correction value of the bucket motor 433; = n zl (t i )+ is the theoretical rotation speed of the bucket motor 433, Δn zl (t i ) is the bucket speed adjustment value of the bucket motor 433.

[0108] S50, obtaining the actual displacement of the bucket hydraulic cylinder 310 when the bucket motor 433 operates at the bucket speed correction value, specifically using the following formula:

[0109] s zs (t i+1 )=f zdwy2 (n zdxz (t i )),,

[0110] Among them, s zs (t i+1 ) is the actual displacement of the bucket hydraulic cylinder 310; f zdwy2 (·) = the actual working model of the bucket drive subsystem 430, f zdwy2 (·)=f zdwy1 (·)+ε1,f zdwy1 (·) is the bucket rotation mechanism model; ε1 is the impact factor, which is used to characterize leakage and thermal effects, etc.

[0111] S60 , replenishing oil to the bucket driving subsystem 430 according to the bucket speed adjustment amount.

[0112] S70 , obtaining a displacement error of the lifting hydraulic cylinder 210 , where the displacement of the lifting hydraulic cylinder 210 is a displacement distance of the lifting cylinder rod 220 relative to the lifting hydraulic cylinder 210 .

[0113] Specifically, the actual displacement of the lifting hydraulic cylinder 210 is obtained by the lifting displacement sensor integrated on the lifting hydraulic cylinder 210, and the theoretical displacement of the lifting hydraulic cylinder 210 is obtained by the lifting mechanism model. Displacement error = actual displacement - theoretical displacement.

[0114] Specifically, step S70 includes the following steps:

[0115] S71. Obtain the flow rate of the lifting hydraulic pump 421. The theoretical speed of the lifting motor 425 is obtained using the lifting speed sensor integrated into the lifting motor 425. The flow rate of the lifting hydraulic pump 421 is equal to the product of the theoretical lifting speed of the lifting motor 425 and the displacement of the lifting hydraulic pump 421. The displacement of the lifting hydraulic pump 421 is known data.

[0116] S72: Then, the theoretical displacement of the lifting hydraulic cylinder 210 is calculated and obtained. The calculation method is as follows:

[0117] When the lifting cylinder rod 220 is extended:

[0118]

[0119] Among them, s tl (t i ) is the theoretical displacement of the lifting hydraulic cylinder 210; q tsl (t i ) is the flow of the lifting hydraulic pump 421; n tl (t i ) V is the theoretical lifting speed of the lifting motor 425; V ts is the displacement of the lifting hydraulic pump 421; A2 is the effective axial cross-sectional area of ​​the lifting rodless chamber 212 of the lifting hydraulic cylinder 210; f tswy1 (·) is the lifting mechanism model, which is known.

[0120] When the lifting cylinder rod 220 is retracted:

[0121]

[0122] Among them, s tl (t i ) is the theoretical displacement of the lifting hydraulic cylinder 210; q tsl (t i ) is the flow of the lifting hydraulic pump 421; n tl (t i ) V is the theoretical lifting speed of the lifting motor 425; V tsis the displacement of the lifting hydraulic pump 421; A3 is the effective axial cross-sectional area of ​​the lifting rod chamber 211 of the lifting hydraulic cylinder 210; f tswy1 (·) is the lifting mechanism model, which is known.

[0123] S80, identify the working state of the accumulator 422, when the actual flow rate q xu (t i ) is greater than the flow threshold [q], the conversion factor μ is selected as 0.5; otherwise, the conversion factor μ is selected as 0.9.

[0124] Specifically, the actual flow rate q of the accumulator 422 is obtained by the lifting flow sensor integrated in the fifth oil discharge port 4213 of the lifting hydraulic pump 421. xu (t i The flow rate threshold [q] of the accumulator 422 may be determined based on operator experience.

[0125] S90 , calculating the lifting speed adjustment amount of the lifting motor 425 according to the conversion factor μ.

[0126] Specifically, the lifting speed adjustment value of the lifting motor 425 is obtained according to the lifting feedback control law of the feedback controller in the lifting drive subsystem 420, and the calculation formula is as follows:

[0127] Δn tl (t i )=μ·f tszs (e sts (t i )),

[0128] Where Δn tl (t i ) = lifting speed adjustment; f tszs (·) is the lifting feedback control law of the feedback controller, which can be obtained according to the corresponding feedback control algorithm and is known; (e sts (t i )) is the displacement error of the lifting hydraulic cylinder 210; μ is the conversion factor.

[0129] S100, judging the lifting oil replenishment action based on the relationship between the lifting speed adjustment amount and the lifting speed adjustment threshold, if the lifting speed adjustment amount Δn tl (t i )≤Lifting speed adjustment threshold [Δn tl ], proceed to steps S110 and S120 in sequence; otherwise, proceed to S130; wherein, the lifting speed adjustment threshold [Δn tl ]The accuracy can be set according to actual work requirements.

[0130] S110: Obtain a lifting speed correction value of the lifting motor 425, specifically using the following formula:

[0131] n tsxz (t i )=n tl (t i )+Δn tl (t i ),

[0132] Among them, n tsxz (t i ) is the lifting speed correction value of the lifting motor 425; n tl (t i ) is the theoretical value of the lifting speed of the lifting motor 425; Δn tl (t i ) is the lifting speed adjustment amount.

[0133] S120: Obtain the actual displacement of the lifting hydraulic cylinder 210 when the lifting motor 425 operates at the lifting speed correction value, specifically using the following formula for calculation:

[0134] s ts (t i+1 )=f tswy2 (n tsxz (t i )),

[0135] Among them, s ts (t i+1 ) = actual displacement of the lifting hydraulic cylinder 210 corrected for lifting; n tsxz (t i ) is the lifting speed correction value of the lifting motor 425; f tswy2 (·) is the actual working model of the lifting drive subsystem 420, f tswy2 (·)=f tswy1 (·)+ε2,f tswy1 (·) is the lifting mechanism model, and ε2 is the impact factor, which is used to characterize leakage and thermal effects, etc.

[0136] S130 , replenishing oil to the lifting drive subsystem 420 according to the lifting speed adjustment amount.

[0137] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Working device, characterized in that, include: A working bucket (100) configured to shovel and load materials; A lifting mechanism (200), connected to the working bucket (100), configured to lift the working bucket (100); A bucket rotating mechanism (300) comprises a bucket rotating hydraulic cylinder (310) and a bucket rotating cylinder rod (320), wherein both ends of the bucket rotating cylinder rod (320) can respectively extend out of the bucket rotating hydraulic cylinder (310) and are coaxially movably arranged in the bucket rotating hydraulic cylinder (310), and one end of the bucket rotating cylinder rod (320) is transmission-connected to the working bucket (100), and the bucket rotating cylinder rod (320) moves along the axial direction of the bucket rotating hydraulic cylinder (310) to drive the working bucket (100) to rotate; A hydraulic drive system (400) includes an oil tank (410) and a lifting drive subsystem (420) and a bucket drive subsystem (430) respectively connected to the oil tank (410), wherein the oil tank (410) can provide oil to the bucket drive subsystem (430) and the lifting drive subsystem (420), and the bucket drive subsystem (430) and the lifting drive subsystem (420) can respectively increase the pressure of the oil to form hydraulic oil, which is supplied to the lifting mechanism (200) and the bucket hydraulic cylinder (310); The lifting drive subsystem (420) includes a lifting hydraulic pump (421) and an accumulator (422). The lifting hydraulic pump (421) is arranged between the oil tank (410) and the lifting mechanism (200) and is capable of absorbing oil in the oil tank (410) and increasing the pressure of the oil to form hydraulic oil. The accumulator (422) is capable of storing excess hydraulic oil discharged by the lifting hydraulic pump (421) and supplying it to the lifting mechanism (200). The priority of the process of the accumulator (422) supplying oil to the lifting mechanism (200) is higher than the priority of the process of the lifting hydraulic pump (421) supplying oil to the lifting mechanism (200); The hydraulic drive system (400) further includes an oil replenishment subsystem (440), wherein the oil replenishment subsystem (440) includes an oil replenishment hydraulic pump (441), wherein the oil replenishment hydraulic pump (441) is connected to the oil tank (410) and is capable of pumping the oil in the oil tank (410) to the lifting mechanism (200), and is also capable of pumping the oil in the oil tank (410) to the bucket hydraulic cylinder (310); The oil replenishment subsystem (440) further includes an oil replenishment motor (442), the oil replenishment motor (442) being connected to the oil replenishment hydraulic pump (441) and capable of driving the oil replenishment hydraulic pump (441) to operate; the speed of the oil replenishment motor (442) is adjustable to control the intermittent start-up of the oil replenishment hydraulic pump (441); The oil replenishment subsystem (440) further includes a second overflow valve (445), which is disposed between the oil replenishment hydraulic pump (441) and the oil tank (410) and is configured to direct excess hydraulic oil discharged from the oil replenishment hydraulic pump (441) to the oil tank (410).

2. The working device according to claim 1, characterized in that: The bucket driving subsystem (430) includes a bucket hydraulic pump (431), and the bucket hydraulic pump (431) is connected to the oil tank (410) and can absorb oil in the oil tank (410); The bucket hydraulic pump (431) comprises a first oil discharge port and a second oil discharge port respectively connected to two bucket rod cavities (311) of the bucket hydraulic cylinder (310), and the bucket hydraulic pump (431) can provide hydraulic oil to the two bucket rod cavities (311) through the first oil discharge port and the second oil discharge port.

3. The working device according to claim 2, characterized in that: The bucket drive subsystem (430) further includes at least two first overflow valves (432); The first overflow valve (432) is provided between the first bucket oil passage between the first oil discharge port and one of the bucket rod chambers (311) and the oil tank (410); The first overflow valve (432) is provided between the second bucket oil passage between the second oil discharge port and the other bucket rod cavity (311) and the oil tank (410); The hydraulic oil in the first bucket oil circuit and the second bucket oil circuit can respectively flow back to the oil tank (410) through the first overflow valve (432).

4. The working device according to claim 1, characterized in that: The oil replenishment subsystem (440) further includes a first one-way valve (443) and a second one-way valve (444). The first one-way valve (443) and the second one-way valve (444) are respectively arranged between the oil replenishment hydraulic pump (441) and the oil supply line connected to the bucket hydraulic cylinder (310), and are configured to prevent the hydraulic oil in the oil supply line from flowing back into the oil tank (410).

5. The working device according to claim 1, characterized in that: The lifting drive subsystem (420) further includes a third one-way valve (423), which is disposed between the oil tank (410) and the accumulator (422) and is configured to prevent the hydraulic oil in the accumulator (422) from flowing into the oil tank (410).

6. The working device according to claim 1, characterized in that: The working device further comprises a movable arm (500) and a fixed bracket (600), the movable arm (500) being rotatably connected to the fixed bracket (600), and the working bucket (100) being rotatably connected to the movable arm (500); and / or, The bucket rotating mechanism (300) further comprises a movably connected rocker arm (330) and a connecting rod (340), wherein the rocker arm (330) is rotatably connected to the movable arm (500), and the connecting rod (340) is rotatably connected to the working bucket (100). One end of the bucket rotating cylinder rod (320) is movably connected to the rocker arm (330), and the other end is movably connected to the fixed bracket (600).

7. The working device according to claim 6, characterized in that: The lifting mechanism (200) includes a lifting hydraulic cylinder (210) and a lifting cylinder rod (220), wherein the lifting hydraulic cylinder (210) is movably connected to the fixed bracket (600), and the lifting cylinder rod (220) is coaxially movably arranged in the lifting hydraulic cylinder (210), and one end of the lifting cylinder rod (220) extending from the lifting hydraulic cylinder (210) is movably connected to the movable arm (500).

8. The working device according to claim 7, characterized in that: The lifting drive subsystem (420) further includes two third overflow valves (424); The lifting hydraulic pump (421) is connected to the lifting rod chamber (211) of the lifting hydraulic cylinder (210) via a first lifting oil circuit; the lifting hydraulic pump (421) is connected to the lifting rodless chamber (212) of the lifting hydraulic cylinder (210) via a second lifting oil circuit; The two third overflow valves (424) are arranged in parallel between the first lifting oil circuit and the second lifting oil circuit in opposite directions, and the hydraulic oil between the first lifting oil circuit and the second lifting oil circuit can flow through the two third overflow valves (424).

9. A loader, characterized in that The invention comprises a cab body (10), a transfer device (20) and a working device according to any one of claims 1 to 8, wherein the transfer device (20) is arranged on the cab body (10) and is configured to drive the cab body (10) to move, and the working device is arranged on the cab body (10).

10. A working device control method, characterized in that: The working device control method is performed based on the working device according to any one of claims 1 to 8; The bucket driving subsystem (430) includes a bucket hydraulic pump (431) and a bucket motor (433), and the bucket motor (433) drives the bucket hydraulic pump (431) to operate; The lifting drive subsystem (420) includes a lifting hydraulic pump (421) and a lifting motor (425), wherein the lifting motor (425) drives the lifting hydraulic pump (421) to operate, and the lifting mechanism (200) includes a lifting hydraulic cylinder (210) and a lifting cylinder rod (220), wherein the lifting cylinder rod (220) is coaxially and movably arranged in the lifting hydraulic cylinder (210); The working device control method includes: S10, obtaining a displacement error of the bucket hydraulic cylinder (310), wherein the displacement of the bucket hydraulic cylinder (310) is a displacement distance of the bucket cylinder rod (320) relative to the bucket hydraulic cylinder (310); S20, calculating the bucket speed adjustment amount of the bucket motor (433) according to the displacement error of the bucket hydraulic cylinder (310); S30, determining the bucket oil replenishment action based on the relationship between the bucket speed adjustment amount and the bucket speed adjustment threshold; if the bucket speed adjustment amount is less than or equal to the bucket speed adjustment threshold, proceed to S40 and S50 in sequence; otherwise, proceed to S60; S40, obtaining a rotation speed correction value of the rotating bucket motor (433); S50, obtaining the corrected actual displacement of the bucket of the bucket hydraulic cylinder (310) when the bucket motor (433) operates at the corrected value of the bucket speed; S60, replenishing oil to the bucket drive subsystem (430) according to the bucket speed adjustment amount; S70, obtaining a displacement error of the lifting hydraulic cylinder (210), wherein the displacement of the lifting hydraulic cylinder (210) is a displacement distance of the lifting cylinder rod (220) relative to the lifting hydraulic cylinder (210); S80, identifying the working state of the accumulator (422), and when the actual flow of the accumulator (422) is greater than the flow threshold, selecting a conversion factor of 0.5; otherwise, selecting a conversion factor of 0.9; S90, calculating the lifting speed adjustment amount of the lifting motor (425) according to the conversion factor; S100, determining a lifting oil replenishment action based on the relationship between the lifting speed adjustment amount and the lifting speed adjustment threshold; if the lifting speed adjustment amount is less than or equal to the lifting speed adjustment threshold, proceed to steps S110 and S120 in sequence; otherwise, proceed to S130; S110, obtaining a lifting speed correction value of the lifting motor (425); S120, obtaining the actual lifting correction displacement of the lifting hydraulic cylinder (210) when the lifting motor (425) operates at the lifting speed correction value; S130, replenishing oil to the lifting drive subsystem (420) according to the lifting speed adjustment amount.

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