Movable arm and bucket composite hydraulic system and excavator

Abstract

The utility model relates to the technical field of excavators, and particularly discloses a movable arm and bucket composite hydraulic system and an excavator, the movable arm and bucket composite hydraulic system comprises a first oil pump, a second oil pump, a first control valve and a second control valve, the first oil pump is used for supplying oil to the first control valve and the second control valve; the second oil pump is used for supplying oil to one of the second control valve and the bucket rodless cavity, the first control valve is used for conveying oil to one of the bucket rodless cavity and the bucket rod cavity, and the second control valve is used for conveying oil to one of the movable arm rodless cavity and the movable arm rod cavity. Oil is supplied to the movable arm oil cylinder and the bucket oil cylinder through the first oil pump, and the second oil pump can independently supply oil to the movable arm oil cylinder or independently supply oil to a rodless cavity of a bucket according to the oil quantity demand difference of the movable arm oil cylinder and the bucket oil cylinder, so that oil can be distributed between the movable arm oil cylinder and the bucket oil cylinder in a balanced manner; and power distribution between the first oil pump and the second oil pump is balanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to excavator technical field especially relates to a kind of dynamic arm and bucket composite hydraulic system and excavator. BACKGROUND

[0002] Traditional excavator is driven by power source to drive hydraulic pump, and the output flow of hydraulic pump usually adopts centralized valve control throttling speed regulation, and is distributed to boom cylinder, arm cylinder and bucket cylinder and other actuators.

[0003] In prior art, such as the earlier patent with application number CN202410831773.8, a kind of networked electro-hydraulic drive system is disclosed, which includes arm cylinder, boom cylinder, bucket cylinder, first pump, second pump and third pump. Among them, when arm cylinder and bucket cylinder composite action, arm cylinder is only supplied by first pump, and bucket cylinder is only supplied by second pump. Since the number of arm cylinder is usually two, and the number of bucket cylinder is usually one, there is a big difference in the number of arm cylinder and bucket cylinder, especially when arm cylinder and bucket cylinder are both extended, it will cause the power demand of the system to the first pump to be much larger than that to the second pump, and then cause the load of the first pump to be too large, affecting its service life. SUMMARY

[0004] The purpose of the utility model is to provide a kind of dynamic arm and bucket composite hydraulic system and excavator, to balance the distribution of power between two oil pumps when dynamic arm and bucket composite motion, to avoid the load of single oil pump being too large.

[0005] On the one hand, the utility model provides a kind of dynamic arm and bucket composite hydraulic system, which includes arm cylinder and bucket cylinder. The arm cylinder includes variable-volume arm rod cavity and arm rodless cavity. The bucket cylinder includes variable-volume bucket rod cavity and bucket rodless cavity. The dynamic arm and bucket composite hydraulic system further includes first oil pump, second oil pump, first control valve and second control valve. The first oil pump is used to supply oil to the first control valve and the second control valve. The second oil pump is used to supply oil to one of the second control valve and the bucket rodless cavity. The first control valve is used to deliver oil to one of the bucket rodless cavity and the bucket rod cavity. The second control valve is used to deliver oil to one of the arm rodless cavity and the arm rod cavity.

[0006] As a preferred technical solution of the dynamic arm and bucket composite hydraulic system, the dynamic arm and bucket composite hydraulic system further includes:

[0007] First oil path, connected with the output end of the first oil pump;

[0008] A bucket large cavity oil path connected with the bucket rodless cavity;

[0009] A bucket small cavity oil path connected with the bucket rod cavity;

[0010] An oil return oil path connected with the oil tank;

[0011] A first connecting oil path connected with the first oil path, the first control valve is connected with the first connecting oil path, the bucket large cavity oil path, the bucket small cavity oil path and the oil return oil path respectively, and the first control valve is configured to enable the first connecting oil path to communicate with one of the bucket large cavity oil path and the bucket small cavity oil path, and enable the oil return oil path to communicate with the other one of the bucket large cavity oil path and the bucket small cavity oil path.

[0012] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises:

[0013] A boom large cavity oil path connected with the boom rodless cavity;

[0014] A boom small cavity oil path connected with the boom rod cavity;

[0015] A second connecting oil path connected with the first oil path, the second control valve is connected with the second connecting oil path, the boom large cavity oil path, the boom small cavity oil path and the oil return oil path respectively, and the second control valve is configured to enable the second connecting oil path to communicate with one of the boom large cavity oil path and the boom small cavity oil path, and enable the oil return oil path to communicate with the other one of the boom large cavity oil path and the boom small cavity oil path.

[0016] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises:

[0017] A first one-way valve arranged in the first connecting oil path, and the first one-way valve is configured to allow oil to flow from the first oil path to the first control valve only;

[0018] A second one-way valve arranged in the second connecting oil path, and the second one-way valve is configured to allow oil to flow from the first oil path to the second control valve only.

[0019] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises a third one-way valve arranged in the first oil path, and the third one-way valve is configured to allow oil to flow from the first oil pump to the first connecting oil path and the second connecting oil path only.

[0020] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises:

[0021] The second oil path is connected with the output end of the second oil pump;

[0022] The third connecting oil path is connected with the second connecting oil path, and the connection position of the third connecting oil path with the second connecting oil path is between the second check valve and the second control valve;

[0023] The third control valve is connected with the second oil path, the bucket rodless cavity and the third connecting oil path respectively, and the third control valve is configured to enable the second oil path to communicate with the bucket rodless cavity or the third connecting oil path.

[0024] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises a fourth check valve arranged in the third connecting oil path, and the fourth check valve is configured to allow oil to flow from the third control valve to the second connecting oil path only; and / or,

[0025] The boom and bucket combined hydraulic system further comprises a fifth check valve arranged between the third control valve and the bucket rodless cavity, and the fifth check valve is configured to allow oil to flow from the third control valve to the bucket rodless cavity only.

[0026] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises a makeup pump, one end of the makeup pump is connected with an oil tank, the other end of the makeup pump is connected with a makeup oil path, and the input ends of the first oil pump and the second oil pump are connected with the makeup oil path.

[0027] As the preferred technical scheme of the boom and bucket combined hydraulic system, the boom and bucket combined hydraulic system further comprises an internal combustion engine, the internal combustion engine is simultaneously connected in transmission with the first oil pump and the second oil pump, and the internal combustion engine can drive the first oil pump and the second oil pump to rotate simultaneously; or,

[0028] The boom and bucket combined hydraulic system further comprises a first motor and a second motor, the first motor is connected in transmission with the first oil pump, and the first motor can drive the first oil pump to rotate, the second motor is connected in transmission with the second oil pump, and the second motor can drive the second oil pump to rotate.

[0029] The boom and bucket combined hydraulic system provided by the utility model has at least the following beneficial effects:

[0030] The boom and bucket combined hydraulic system includes a first oil pump, a second oil pump, a first control valve, and a second control valve. The first oil pump supplies oil to both the first and second control valves. The second oil pump supplies oil to either the second control valve or the rodless chamber of the bucket. The first control valve delivers oil to either the rodless chamber or the rod chamber of the bucket, and the second control valve delivers oil to either the rodless chamber or the rod chamber of the boom. The first oil pump supplies oil to both the boom and bucket cylinders, while the second oil pump can supply oil to either the boom cylinder or the rodless chamber of the bucket, depending on the oil demand of the boom and bucket cylinders. This allows for a balanced distribution of oil between the boom and bucket cylinders, thereby balancing the power distribution between the first and second oil pumps and preventing excessive load on any single pump.

[0031] On the other hand, this utility model provides an excavator, including the boom and bucket combined hydraulic system of any of the above-mentioned solutions. The excavator also includes an excavator body, a boom, a stick, a bucket, and a stick cylinder. The boom is hinged to the excavator body, the stick is hinged to the boom, the bucket is hinged to the stick, the boom cylinder body of the boom cylinder is hinged to the excavator body, the boom piston rod of the boom cylinder is hinged to the boom, the stick cylinder body of the stick cylinder is hinged to the boom, the stick piston rod of the stick cylinder is hinged to the stick, the bucket cylinder body of the bucket cylinder is hinged to the stick, and the bucket piston rod of the bucket cylinder is hinged to the bucket.

[0032] The excavator provided by this utility model has at least the following beneficial effects:

[0033] The excavator includes the aforementioned boom and bucket combined hydraulic system, which enables the hydraulic fluid to be evenly distributed between the boom cylinder and the bucket cylinder, thereby balancing the power distribution between the first pump 4 and the second pump 5 and avoiding excessive load on a single pump. Attached Figure Description

[0034] Figure 1 This is a first structural schematic diagram of the boom and bucket combined hydraulic system in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the second structure of the boom and bucket combined hydraulic system in this embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the excavator's substructure in an embodiment of this utility model.

[0037] In the picture:

[0038] 1. Boom cylinder; 101. Boom rod chamber; 102. Boom rodless chamber;

[0039] 2. Bucket cylinder; 201. Bucket rod chamber; 202. Bucket rodless chamber;

[0040] 3, oil top-up motor; 4, first oil pump; 5, second oil pump; 6, oil top-up pump; 7, oil tank; 8, oil top-up oil circuit; 9, oil top-up overflow valve; 10, first oil circuit; 11, large cavity oil circuit of bucket; 12, small cavity oil circuit of bucket; 13, oil return oil circuit; 14, first connecting oil circuit; 15, first control valve; 16, large cavity oil circuit of boom; 17, small cavity oil circuit of boom; 18, second connecting oil circuit; 19, second control valve; 20, first check valve; 21, second check valve; 22, third check valve; 23, second oil circuit; 24, third connecting oil circuit; 25, third control valve; 26, fourth check valve; 27, fifth check valve; 28, hydraulic control check valve; 29, electromagnetic reversing valve; 30, internal combustion engine; 31, first motor; 32, second motor;

[0041] 33, arm cylinder; 3301, arm rod cavity; 3302, arm rodless cavity;

[0042] 34, third oil pump; 35, fourth oil pump; 36, third oil circuit; 37, fourth oil circuit; 38, fifth oil circuit; 39, flow balance valve; 40, fourth control valve; 41, fifth control valve; 42, hydraulic control reversing valve; 43, third motor; 44, battery. DETAILED DESCRIPTION

[0043] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0044] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the devices or elements indicated to have a specific orientation, to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the "upper", "above" and "on" of the first feature relative to the second feature include the vertical direction of the first feature above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature relative to the second feature include the vertical direction of the first feature below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0045] In the description of the utility model, it needs to explain, unless another explicit stipulation and limit, term " install " " link " " connection " should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected, can be mechanical connection, also can be electrical connection, can be direct connection, also can be indirectly connected through intermediate medium, can be two element internal communication. For ordinary skilled in the art, the above-mentioned term can be understood in the utility model with the specific meaning of the specific situation.

[0046] The embodiments of the utility model are described in detail below, the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model and cannot be understood as a limitation of the utility model.

[0047] In the prior art, when the boom cylinder and the bucket cylinder are combined to act, the boom cylinder is only supplied with oil by the first pump, and the bucket cylinder is only supplied with oil by the second pump. Since the number of boom cylinders is usually two and the number of bucket cylinders is usually one, there is a large difference in the number of boom cylinders and bucket cylinders, especially when the boom cylinder and the bucket cylinder are both extended, which will cause the power demand of the system to the first pump to be much greater than the power demand of the system to the second pump, and further cause the load of the first pump to be too large, affecting the service life thereof.

[0048] To this end, the embodiment provides a boom and bucket combined hydraulic system to solve the above problems.

[0049] Please refer to Figure 1 and Figure 2 The boom and bucket combined hydraulic system comprises a boom cylinder 1 and a bucket cylinder 2.

[0050] The boom cylinder 1 comprises a boom rod cavity 101 and a boom rodless cavity 102 with variable volumes. The boom cylinder 1 further comprises a boom piston rod and a boom cylinder body. The boom piston rod separates the inner cavity of the boom cylinder body into the boom rod cavity 101 and the boom rodless cavity 102. The boom piston rod passes through the boom rod cavity 101 so that the cross-sectional area of the boom rod cavity 101 is smaller than that of the boom rodless cavity 102. The boom piston rod can move in the boom cylinder body, and when the boom piston rod moves, the volumes of the boom rod cavity 101 and the boom rodless cavity 102 increase and decrease respectively. In this embodiment, the number of boom cylinders 1 is two.

[0051] The bucket oil cylinder 2 comprises a bucket rod cavity 201 and a bucket rodless cavity 202 with variable volumes, and further comprises a bucket piston rod and a bucket cylinder body, the bucket piston rod separates the inner cavity of the bucket cylinder body into the bucket rod cavity 201 and the bucket rodless cavity 202, the bucket piston rod passes through the bucket rod cavity 201 so that the sectional area of the bucket rod cavity 201 is smaller than that of the bucket rodless cavity 202, the bucket piston rod can move in the bucket cylinder body, and when the bucket piston rod moves, the volumes of the bucket rod cavity 201 and the bucket rodless cavity 202 increase and decrease respectively. In the embodiment, the number of the bucket oil cylinder 2 is one.

[0052] Please refer to Figure 1 and Figure 2 , the boom and bucket combined hydraulic system further comprises a first oil pump 4, a second oil pump 5, a first control valve 15 and a second control valve 19, the first oil pump 4 is used to supply oil to the first control valve 15 and the second control valve 19, the second oil pump 5 is used to supply oil to one of the second control valve 19 and the bucket rodless cavity 202, the first control valve 15 is used to deliver oil to one of the bucket rodless cavity 202 and the bucket rod cavity 201, and the second control valve 19 is used to deliver oil to one of the boom rodless cavity 102 and the boom rod cavity 101. In this way, the boom oil cylinder 1 and the bucket oil cylinder 2 are supplied with oil by the first oil pump 4, and the second oil pump 5 can supply oil to the boom oil cylinder 1 alone or to the bucket rodless cavity 202 alone according to the difference in oil amount demand of the boom oil cylinder 1 and the bucket oil cylinder 2, so that the oil can be evenly distributed between the boom oil cylinder 1 and the bucket oil cylinder 2, and the power distribution between the first oil pump 4 and the second oil pump 5 is balanced, thereby avoiding excessive load on a single oil pump.

[0053] Specifically, in the embodiment, when the boom rodless cavity 102, the boom rod cavity 101 and the bucket rodless cavity 202 have oil amount demands, the second oil pump 5 needs to supply in sequence. Among them, the second oil pump 5 supplies oil to the boom rodless cavity 102 in the first sequence, supplies oil to the bucket rodless cavity 202 in the second sequence, and supplies oil to the boom rod cavity 101 in the third sequence.

[0054] It can be understood that, in the embodiment, since the number of the boom oil cylinder 1 is two, and the boom oil cylinder 1 and the bucket oil cylinder 2 themselves have different models, the flow demand of the boom rodless chamber 102 of the boom oil cylinder 1 for oil, the flow demand of the bucket rodless chamber 202 of the bucket oil cylinder 2 for oil, and the flow demand of the boom rod chamber 101 of the boom oil cylinder 1 for oil are sequentially reduced. Therefore, no matter the boom oil cylinder 1 acts alone, the bucket oil cylinder 2 acts alone, or the boom oil cylinder 1 and the bucket oil cylinder 2 compound, the second oil pump 5 needs to preferentially supply oil to the boom rodless chamber 102, then to the bucket rodless chamber 202, and finally to the boom rod chamber 101, so that the power distribution between the first oil pump 4 and the second oil pump 5 is more balanced.

[0055] Please refer to Figure 1 and Figure 2 , the boom and bucket compound hydraulic system further comprises a makeup pump 6. One end of the makeup pump 6 is connected to the oil tank 7, and the other end is connected to a makeup oil path 8. The makeup pump 6 can pump the oil in the oil tank 7 to the makeup oil path 8, and supply oil to the first oil pump 4 and the second oil pump 5 through the makeup oil path 8. In the embodiment, the makeup pump 6 is specifically an open pump. Preferably, the boom and bucket compound hydraulic system further comprises a makeup overflow valve 9 connected to the makeup oil path 8. The makeup overflow valve 9 is used to overflow the oil in the makeup oil path 8 that exceeds the set pressure to the oil tank 7.

[0056] Optionally, please refer to Figure 1 and Figure 2 , the boom and bucket compound hydraulic system further comprises a first oil path 10, a bucket large chamber oil path 11, a bucket small chamber oil path 12, a return oil path 13, and a first connection oil path 14. The first oil path 10 is connected to the output end of the first oil pump 4. The bucket large chamber oil path 11 is connected to the bucket rodless chamber 202. The bucket small chamber oil path 12 is connected to the bucket rod chamber 201. The return oil path 13 is connected to the oil tank 7. The first connection oil path 14 is connected to the first oil path 10. The first control valve 15 is connected to the first connection oil path 14, the bucket large chamber oil path 11, the bucket small chamber oil path 12, and the return oil path 13, respectively. The first control valve 15 is configured to enable the first connection oil path 14 to communicate with one of the bucket large chamber oil path 11 and the bucket small chamber oil path 12, and enable the return oil path 13 to communicate with the other one of the bucket large chamber oil path 11 and the bucket small chamber oil path 12. In this way, the first oil pump 4 can supply oil to the bucket rodless chamber 202 or the bucket rod chamber 201 through the first control valve 15.

[0057] Specifically, the first control valve 15 at least comprises a P1 interface, an A 11 interface, an A 12 interface, and a T1 interface. The P1 interface is connected to the first connection oil path 14. The A 11 interface is connected to the bucket large chamber oil path 11. The A12 The interface connects to the small chamber oil circuit 12 of the bucket, and the T1 interface connects to the return oil circuit 13. The first control valve 15 has a first left position and a first right position, such as... Figure 1 As shown, when the first control valve 15 is in the first left position, the P1 interface is connected to A. 11 Interface connected, A 12 The interface is connected to the T1 interface, thereby connecting the first connecting oil passage 14 to the bucket large chamber oil passage 11, and the return oil passage 13 to the bucket small chamber oil passage 12. The oil pumped by the first oil pump 4 can be sequentially transported to the bucket rodless chamber 202 through the first connecting oil passage 14, the first control valve 15, and the bucket large chamber oil passage 11. The oil in the bucket rod chamber 201 flows back to the oil tank 7 sequentially through the bucket small chamber oil passage 12, the first control valve 15, and the return oil passage 13, causing the bucket piston rod to extend. Figure 2 As shown, when the first control valve 15 is in the first right position, the P1 interface is connected to A. 12 Interface connected, A 11 The interface is connected to the T1 interface, thereby connecting the first connecting oil passage 14 to the bucket small chamber oil passage 12. The oil pumped by the first oil pump 4 can be delivered to the bucket rod chamber 201 through the first connecting oil passage 14, the first control valve 15 and the bucket small chamber oil passage 12 in sequence. The oil in the bucket rodless chamber 202 flows back to the oil tank 7 through the bucket large chamber oil passage 11, the first control valve 15 and the return oil passage 13 in sequence, causing the bucket piston rod to retract.

[0058] Alternatively, please refer to Figure 1 and Figure 2 The boom and bucket combined hydraulic system also includes a boom large chamber oil circuit 16, a boom small chamber oil circuit 17, and a second connecting oil circuit 18. The boom large chamber oil circuit 16 is connected to the boom rodless chamber 102; the boom small chamber oil circuit 17 is connected to the boom rod chamber 101; the second connecting oil circuit 18 is connected to the first oil circuit 10; and a second control valve 19 is connected to the second connecting oil circuit 18, the boom large chamber oil circuit 16, the boom small chamber oil circuit 17, and the return oil circuit 13. The second control valve 19 is configured to connect the second connecting oil circuit 18 to one of the boom large chamber oil circuit 16 and the boom small chamber oil circuit 17, and to connect the return oil circuit 13 to the other of the boom large chamber oil circuit 16 and the boom small chamber oil circuit 17. This configuration allows the first oil pump 4 to supply oil to the boom rod chamber 101 or the boom rodless chamber 102 via the second control valve 19.

[0059] Specifically, in this embodiment, the second control valve 19 includes at least a P2 port and an A port. 21 Interface, A 22 Interface and T2 interface, P2 interface connect to the second connection oil circuit 18, A 21 Interface connection to boom large chamber hydraulic circuit 16, A 22The interface connects to the boom small chamber oil circuit 17, the T2 interface connects to the return oil circuit 13, and the second control valve 19 has a second left position and a second right position, such as... Figure 1 As shown, when the second control valve 19 is in the second right position, the P2 port is connected to A. 21 Interface connected, A 22 The interface is connected to the T2 interface, thereby connecting the second connecting oil passage 18 to the boom large chamber oil passage 16, and the return oil passage 13 to the boom small chamber oil passage 17. The oil pumped by the first oil pump 4 can be sequentially transported to the boom rodless chamber 102 through the second connecting oil passage 18, the second control valve 19, and the boom large chamber oil passage 16. The oil in the boom rod chamber 101 flows back to the oil tank 7 sequentially through the boom small chamber oil passage 17, the second control valve 19, and the return oil passage 13, causing the boom piston rod to extend. Figure 2 As shown, when the second control valve 19 is in the second left position, the P2 interface is connected to A. 22 Interface connected, A 21 The interface is connected to the T2 interface, thereby connecting the second connecting oil passage 18 to the boom small chamber oil passage 17. The oil pumped by the first oil pump 4 can be delivered to the boom rod chamber 101 through the second connecting oil passage 18, the second control valve 19 and the boom small chamber oil passage 17 in sequence. The oil in the boom rodless chamber 102 flows back to the oil tank 7 through the boom large chamber oil passage 16, the second control valve 19 and the return oil passage 13 in sequence, causing the boom piston rod to retract.

[0060] Alternatively, please refer to Figure 1 and Figure 2 The boom and bucket combined hydraulic system also includes a first check valve 20 and a second check valve 21. The first check valve 20 is located in the first connecting oil passage 14 and is configured to allow oil to flow only from the first oil passage 10 to the first control valve 15. The second check valve 21 is located in the second connecting oil passage 18 and is configured to allow oil to flow only from the first oil passage 10 to the second control valve 19. By setting the first check valve 20 and the second check valve 21, backflow of oil in the first connecting oil passage 14 and the second connecting oil passage 18 can be prevented, and the oil pumped by the first oil pump 4 to the first control valve 15 and the oil to the second control valve 19 can be kept separate.

[0061] Alternatively, please refer to Figure 1 and Figure 2 The boom and bucket combined hydraulic system also includes a third check valve 22 located in the first oil circuit 10. The third check valve 22 is configured to allow oil to flow only from the first oil pump 4 to the first connecting oil circuit 14 and the second connecting oil circuit 18. By providing the third check valve 22, it is possible to further prevent oil from flowing back from the first connecting oil circuit 14 and the second connecting oil circuit 18 to the first oil circuit 10.

[0062] Alternatively, please refer toFigure 1 and Figure 2 The boom and bucket combined hydraulic system further comprises a second oil path 23, a third connecting oil path 24 and a third control valve 25. The second oil path 23 is connected with the output end of the second oil pump 5. The third connecting oil path 24 is connected with the second connecting oil path 18, and the connection between the third connecting oil path 24 and the second connecting oil path 18 is located between the second one-way valve 21 and the second control valve 19. The third control valve 25 is connected with the second oil path 23, the bucket rodless cavity 202 and the third connecting oil path 24 respectively, and is configured to enable the second oil path 23 to communicate with the bucket rodless cavity 202 or the third connecting oil path 24. In this way, the second oil pump 5 can supply oil to the bucket rodless cavity 202 through the third control valve 25, or the second oil pump 5 can supply oil to the boom rodless cavity 102 or the boom rod cavity 101 through the cooperation of the second control valve 19 and the third control valve 25.

[0063] Specifically, the third control valve 25 at least comprises a P3 interface, an A 31 interface and an A 32 interface, the P3 interface is connected with the second oil path 23, the A 31 interface is connected with the third connecting oil path 24, and the A 32 interface is connected with the bucket rodless cavity 202. The third control valve 25 has a third left position and a third right position. As shown in Figure 1 , when the third control valve 25 is in the third left position, the P3 interface communicates with the A 32 interface, the A 31 interface is disconnected, thereby enabling the second oil path 23 to communicate with the bucket large cavity oil path 11. The oil pumped by the second oil pump 5 can be sequentially delivered to the bucket rodless cavity 202 through the second oil path 23 and the third control valve 25, so that the bucket piston rod extends out. As shown in Figure 2 , when the third control valve 25 is in the third right position, the P3 interface communicates with the A 31 interface, the A 32 interface is disconnected, thereby enabling the second oil path 23 to communicate with the third connecting oil path 24. The oil pumped by the second oil pump 5 can be sequentially delivered to the P2 interface of the second control valve 19 through the second oil path 23, the third control valve 25, the third connecting oil path 24 and the second connecting oil path 18. When the second control valve 19 is in the second right position, the oil is finally delivered to the boom rodless cavity 102, so that the boom piston rod extends out. When the second control valve 19 is in the second left position, the oil is finally delivered to the boom rod cavity 101, so that the boom piston rod retracts.

[0064] Optionally, please refer to Figure 1 and Figure 2The boom and bucket combined hydraulic system further comprises a fourth check valve 26 arranged on the third connecting oil path 24, the fourth check valve 26 is configured to allow oil flow only from the third control valve 25 to the second connecting oil path 18, since the third connecting oil path 24 and the second connecting oil path 18 are communicated, by arranging the fourth control valve 40, the backflow of oil in the second connecting oil path 18 to the third control valve 25 through the third connecting oil path 24 can be avoided.

[0065] Optionally, referring to Figure 1 and Figure 2 The boom and bucket combined hydraulic system further comprises a fifth check valve 27 arranged between the third control valve 25 and the bucket rodless cavity 202, the fifth check valve 27 is configured to allow oil flow only from the third control valve 25 to the bucket rodless cavity 202. By arranging the fifth check valve 27, the backflow of oil in the bucket rodless cavity 202 to the third control valve 25 can be avoided.

[0066] In the embodiment, the first control valve 15, the second control valve 19 and the third control valve 25 are all solenoid valves, in other embodiments, the first control valve 15, the second control valve 19 and the third control valve 25 can also be arranged as needed.

[0067] Optionally, referring to Figure 1 and Figure 2 The boom and bucket combined hydraulic system further comprises a hydraulic control check valve 28 arranged on the bucket large cavity oil path 11, the hydraulic control check valve 28 is used to open or close the bucket large cavity oil path 11, and when the hydraulic control check valve 28 closes the bucket large cavity oil path 11, the pressure of the oil in the bucket rodless cavity 202 can be ensured to be stable, thereby keeping the position of the bucket piston rod stable.

[0068] The hydraulic control check valve 28 comprises a check valve valve shell and a check valve spool, the check valve valve shell has a first working interface and a second working interface, the first working interface and the second working interface are connected in series on the bucket large cavity oil path 11, and the first working interface is closer to the bucket rodless cavity 202 than the second working interface; the check valve spool is slidably arranged in the check valve valve shell, the check valve spool divides the inner cavity of the check valve valve shell into a spring cavity and a working cavity, the check valve spool can slide relative to the check valve valve shell to have an open position and a closed position, when the check valve spool is in the closed position, the check valve spool can further divide the working cavity into a first cavity and a second cavity which are not communicated with each other, wherein the first working interface is always communicated with the first cavity, and the second working interface is always communicated with the second cavity, since the first cavity and the second cavity are separated, the bucket large cavity oil path 11 is disconnected; when the check valve spool is in the open position, the first cavity and the second cavity are communicated, at this time the bucket large cavity oil path 11 is communicated.

[0069] The hydraulic control check valve 28 further comprises a check valve spring, the check valve spool is in abutment with the check valve spool and the check valve spool at both ends of the check valve spring in the spring cavity, the first control interface is always in communication with the first cavity, the second control interface is always in communication with the spring cavity, the check valve spring and the hydraulic oil in the spring cavity give the check valve spool a force F1 to move to the closed position, the hydraulic oil in the working cavity gives the check valve spool a force F2 to move to the open position, and the size of F1 and F2 is compared to determine the position of the check valve spool.

[0070] Further, the boom and bucket combined hydraulic system further comprises an electromagnetic reversing valve 29, which is a two-position three-way valve, used to make the first control interface and the second control interface of the hydraulic control check valve 28 communicate, at this time the oil pressure in the working cavity and the spring cavity of the hydraulic control check valve 28 is equal, and the check valve spring in the spring cavity also gives the check valve spool a force to move to the closed position, ensuring that the bucket large cavity oil way 11 is closed stably. The electromagnetic reversing valve 29 can also make the second control interface communicate with the oil tank 7 and the first control interface be disconnected, at this time F1 and F2 are compared with each other to determine the position of the check valve spool, when F2 is greater than F1, the check valve spring is compressed, which can make the check valve spool move to the open position, thereby making the bucket large cavity oil way 11 open.

[0071] Optionally, please refer to Figure 1 , the boom and bucket combined hydraulic system further comprises an internal combustion engine 30, the internal combustion engine 30 is drivingly connected with the first oil pump 4 and the second oil pump 5, and the internal combustion engine 30 can drive the first oil pump 4 and the second oil pump 5 to rotate at the same time; in this way, the first oil pump 4 and the second oil pump 5 can be driven to rotate by the internal combustion engine 30. Preferably, the internal combustion engine 30 is further drivingly connected with the oil supplement pump 6, and the internal combustion engine 30 can also drive the oil supplement pump 6 to rotate.

[0072] As one of the alternative solutions, as shown in Figure 2 , the boom and bucket combined hydraulic system further comprises a first motor 31 and a second motor 32, the first motor 31 is drivingly connected with the first oil pump 4, and the first motor 31 can drive the first oil pump 4 to rotate, the second motor 32 is drivingly connected with the second oil pump 5, and the second motor 32 can drive the second oil pump 5 to rotate. Preferably, the boom and bucket combined hydraulic system further comprises an oil supplement motor 3, the oil supplement motor 3 is drivingly connected with the oil supplement pump 6, and the oil supplement motor 3 is used to drive the oil supplement pump 6 to rotate. Further preferably, the boom and bucket combined hydraulic system further comprises a battery 44, and the motors are electrically connected with the first motor 31, the second motor 32 and the third motor 43 respectively.

[0073] Please refer to Figures 1 to 3The embodiment also provides a shovel comprising the boom and bucket combined hydraulic system, and the shovel further comprises a shovel body, a boom, a stick, a bucket and a stick cylinder 33. The boom is hinged to the shovel body, the stick is hinged to the boom, the bucket is hinged to the stick, a boom cylinder body of the boom cylinder 1 is hinged to the shovel body, a boom piston rod of the boom cylinder 1 is hinged to the boom, a stick cylinder body of the stick cylinder 33 is hinged to the boom, a stick piston rod of the stick cylinder 33 is hinged to the stick, a bucket cylinder body of the bucket cylinder 2 is hinged to the stick, and a bucket piston rod of the bucket cylinder 2 is hinged to the bucket. The shovel comprises the boom and bucket combined hydraulic system, and the boom and bucket combined hydraulic system can balance the distribution of oil between the boom cylinder 1 and the bucket cylinder 2, and then balance the power distribution between the first oil pump 4 and the second oil pump 5, so that the load of a single oil pump is avoided from being too large.

[0074] The stick cylinder 33 comprises a variable-volume stick rod cavity 3301 and a stick rodless cavity 3302, and further comprises a stick piston rod and a stick cylinder body. The stick piston rod divides an inner cavity of the stick cylinder body into the stick rod cavity 3301 and the stick rodless cavity 3302. The stick piston rod passes through the stick rod cavity 3301, so that a sectional area of the stick rod cavity 3301 is smaller than that of the stick rodless cavity 3302. The stick piston rod can move in the stick cylinder body, and when the stick piston rod moves, the volumes of the stick rod cavity 3301 and the stick rodless cavity 3302 increase and decrease respectively. In the embodiment, the stick cylinder body is hinged to the boom, the stick piston rod is hinged to the stick, and the number of the stick cylinder 33 is one.

[0075] Optionally, the excavator further comprises a third oil pump 34, a fourth oil pump 35, a third oil line 36, a fourth oil line 37, a fifth oil line 38, two fourth control valves 40 and a flow balance valve 39. The third oil pump 34 is connected to the third oil line 36 at one end, and the third oil line 36 is connected to the stick rod rodless cavity 3302. The third oil pump 34 is connected to the fourth oil line 37 at the other end, and the fourth oil line 37 is connected to the stick rod rod cavity 3301. The fourth oil pump 35 is connected to the oil supplement line 8 at one end, and the fourth oil pump 35 is connected to the fifth oil line 38 at the other end. The fifth oil line 38 is connected to the third oil line 36. The first fourth control valve 40 is arranged on the third oil line 36 between the connection of the third oil line 36 and the fifth oil line 38 and the stick rod rodless cavity 3302, and is used to control the connection and disconnection of the third oil line 36. The second fourth control valve 40 is arranged on the fourth oil line 37, and is used to control the connection and disconnection of the fourth oil line 37. When the oil pressure in the stick rod rodless cavity 3302 is greater than the oil pressure in the stick rod rod cavity 3301, the flow balance valve 39 connects the fourth oil line 37 and the oil supplement line 8. When the oil pressure in the stick rod rodless cavity 3302 is less than the oil pressure in the stick rod rod cavity 3301, the flow balance valve 39 connects the third oil line 36 and the oil supplement line 8. The third oil pump 34 and the two oil chambers of the stick rod oil cylinder 33 form a hydraulic circuit, the fourth oil pump 35 and the stick rod rodless cavity 3302 and the oil supplement line 8 form a hydraulic circuit, and the flow balance valve 39 can realize the replacement of the high-temperature oil in the hydraulic circuit and the low-temperature oil in the oil supplement line 8, so as to ensure the normal oil temperature in the hydraulic circuit, and further ensure the normal work of the bucket oil cylinder 2.

[0076] It should be noted that in the present embodiment, the third oil pump 34 and the fourth oil pump 35 are both closed pumps.

[0077] The flow balance valve 39 comprises a P4 interface, an A4 interface and a B4 interface. The P4 interface is connected to the oil supplement line 8, the A4 interface is connected to the third oil line 36, and the B4 interface is connected to the fourth oil line 37. The flow balance valve 39 has a fourth left position and a fourth right position. When the flow balance valve 39 is in the fourth left position, the flow balance valve 39 connects the P4 interface and the B4 interface, and disconnects the A4 interface, so that the oil supplement line 8 is connected to the fourth oil line 37, and the oil supplement line 8 is disconnected from the third oil line 36. When the flow balance valve 39 is in the fourth right position, the flow balance valve 39 connects the P4 interface and the A4 interface, and disconnects the B4 interface, so that the oil supplement line 8 is connected to the third oil line 36, and the oil supplement line 8 is disconnected from the fourth oil line 37. Preferably, the flow balance valve 39 further has a first neutral position. When the flow balance valve 39 is in the first neutral position, the P4 interface is disconnected, the A4 interface is disconnected, and the B4 interface is disconnected, so that the oil supplement line 8 is disconnected from the third oil line 36 and the fourth oil line 37.

[0078] The flow balance valve 39 also has a first hydraulic control end and a second hydraulic control end, the first hydraulic control end is connected with the third oil path 36, the second hydraulic control end is connected with the fourth oil path 37, the first hydraulic control end and the second hydraulic control end are respectively located on both sides of a valve core of the flow balance valve 39, and oil in the first hydraulic control end and the second hydraulic control end directly acts on the valve core of the flow balance valve 39, and the force of the oil in the first hydraulic control end acting on the valve core of the flow balance valve 39 and the force of the oil in the second hydraulic control end acting on the valve core of the flow balance valve 39 are compared to determine the stop position of the valve core of the flow balance valve 39.

[0079] The fourth control valve 40 has the same structure as the hydraulic control one-way valve 28, and details are not repeated here. Two hydraulic control reversing valves 42 are arranged corresponding to the two fourth control valves 40, and each fourth control valve 40 is controlled by the corresponding hydraulic control reversing valve 42 to control the first control interface and the second control interface to be communicated or the first control interface to be disconnected and the second control interface to be communicated with the oil return oil path 13. The hydraulic control reversing valve 42 specifically adopts a two-position three-way valve.

[0080] Optionally, the excavator further comprises a fifth control valve 41 arranged on the third oil path 36, the fifth control valve 41 is located between the third oil path 36 and the fifth oil path 38 and between the third oil pump 34, and the fifth control valve 41 is used to control the third oil path 36 to be communicated or disconnected.

[0081] Optionally, the excavator further comprises a third motor 43 capable of forward rotation and reverse rotation, the third motor 43 is in driving connection with the third oil pump 34 and the fourth oil pump 35 respectively, and the third motor 43 can simultaneously drive the third oil pump 34 and the fourth oil pump 35 to rotate, and a battery 44 is in electrical connection with the first motor 31, the second motor 32, the third motor 43 and the oil supplement motor 3 respectively. The rotation speed of the third motor 43 is controlled to control the extension and retraction speed of the boom piston rod of the boom cylinder 1. When the boom piston rod is retracted, the boom is lowered by its own weight, the fourth oil pump 35 drives the third motor 43 to reverse, which can generate electricity and store in the battery 44, thereby realizing the recycling of system energy.

[0082] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not a limitation on the embodiments of the utility model. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model claims.

Claims

1. A boom and bucket combined hydraulic system, comprising a boom cylinder (1) and a bucket cylinder (2), wherein the boom cylinder (1) includes a boom rod chamber (101) and a boom rodless chamber (102) with variable volumes, and the bucket cylinder (2) includes a bucket rod chamber (201) and a bucket rodless chamber (202) with variable volumes, characterized in that, The boom and bucket combined hydraulic system also includes a first oil pump (4), a second oil pump (5), a first control valve (15), and a second control valve (19). The first oil pump (4) is used to supply oil to the first control valve (15) and the second control valve (19). The second oil pump (5) is used to supply oil to either the second control valve (19) or the rodless chamber (202) of the bucket. The first control valve (15) is used to deliver oil to either the rodless chamber (202) of the bucket or the rod chamber (201) of the bucket. The second control valve (19) is used to deliver oil to either the rodless chamber (102) of the boom or the rod chamber (101) of the boom.

2. The boom and bucket combined hydraulic system according to claim 1, characterized in that, The boom and bucket combined hydraulic system also includes: The first oil passage (10) is connected to the output end of the first oil pump (4); The large chamber oil passage (11) of the bucket is connected to the rodless chamber (202) of the bucket; The small chamber oil passage (12) of the bucket is connected to the rod chamber (201) of the bucket; The return oil line (13) is connected to the oil tank (7); A first connecting oil passage (14) is connected to the first oil passage (10). A first control valve (15) is connected to the first connecting oil passage (14), the large chamber oil passage (11), the small chamber oil passage (12), and the return oil passage (13), respectively. The first control valve (15) is configured to enable the first connecting oil passage (14) to communicate with one of the large chamber oil passage (11) and the small chamber oil passage (12), and to enable the return oil passage (13) to communicate with the other of the large chamber oil passage (11) and the small chamber oil passage (12).

3. The boom and bucket combined hydraulic system according to claim 2, characterized in that, The boom and bucket combined hydraulic system also includes: The boom large cavity oil passage (16) is connected to the boom rodless cavity (102); The boom small cavity oil passage (17) is connected to the boom rod cavity (101); The second connecting oil passage (18) is connected to the first oil passage (10). The second control valve (19) is connected to the second connecting oil passage (18), the boom large chamber oil passage (16), the boom small chamber oil passage (17), and the return oil passage (13). The second control valve (19) is configured to connect the second connecting oil passage (18) to one of the boom large chamber oil passage (16) and the boom small chamber oil passage (17), and to connect the return oil passage (13) to the other of the boom large chamber oil passage (16) and the boom small chamber oil passage (17).

4. The boom and bucket combined hydraulic system according to claim 3, characterized in that, The boom and bucket combined hydraulic system also includes: A first check valve (20) is provided in the first connecting oil passage (14), and the first check valve (20) is configured to allow oil to flow from the first oil passage (10) to the first control valve (15) only; A second check valve (21) is provided in the second connecting oil passage (18), and the second check valve (21) is configured to allow oil to flow only from the first oil passage (10) to the second control valve (19).

5. The boom and bucket combined hydraulic system according to claim 4, characterized in that, The boom and bucket combined hydraulic system also includes a third check valve (22) disposed in the first oil circuit (10), and the third check valve (22) is configured to allow oil to flow only from the first oil pump (4) to the first connecting oil circuit (14) and the second connecting oil circuit (18).

6. The boom and bucket combined hydraulic system according to claim 4, characterized in that, The boom and bucket combined hydraulic system also includes: The second oil passage (23) is connected to the output end of the second oil pump (5); The third connecting oil passage (24) is connected to the second connecting oil passage (18), and the connection point between the third connecting oil passage (24) and the second connecting oil passage (18) is located between the second check valve (21) and the second control valve (19). The third control valve (25) is connected to the second oil circuit (23), the bucket rodless chamber (202), and the third connecting oil circuit (24), respectively, and the third control valve (25) is configured to enable the second oil circuit (23) to communicate with the bucket rodless chamber (202) or the third connecting oil circuit (24).

7. The boom and bucket combined hydraulic system according to claim 6, characterized in that, The boom and bucket combined hydraulic system further includes a fourth check valve (26) disposed in the third connecting oil circuit (24), the fourth check valve (26) being configured to allow oil to flow only from the third control valve (25) to the second connecting oil circuit (18); and / or, The boom and bucket combined hydraulic system also includes a fifth check valve (27) disposed between the third control valve (25) and the bucket rodless chamber (202), the fifth check valve (27) being configured to allow oil to flow only from the third control valve (25) to the bucket rodless chamber (202).

8. The boom and bucket combined hydraulic system according to any one of claims 1-7, characterized in that, The boom and bucket combined hydraulic system also includes a replenishing pump (6), one end of which is connected to an oil tank (7) and the other end is connected to a replenishing oil circuit (8). The input ends of the first oil pump (4) and the second oil pump (5) are both connected to the replenishing oil circuit (8).

9. The boom and bucket combined hydraulic system according to any one of claims 1-7, characterized in that, The boom and bucket combined hydraulic system also includes an internal combustion engine (30), which is simultaneously connected to the first oil pump (4) and the second oil pump (5), and the internal combustion engine (30) can drive the first oil pump (4) and the second oil pump (5) to rotate simultaneously; or, The boom and bucket combined hydraulic system also includes a first motor (31) and a second motor (32). The first motor (31) is connected to the first oil pump (4) and can drive the first oil pump (4) to rotate. The second motor (32) is connected to the second oil pump (5) and can drive the second oil pump (5) to rotate.

10. An excavator, characterized in that, The excavator includes the boom and bucket combined hydraulic system according to any one of claims 1-9, and further includes the excavator body, boom, stick, bucket and stick cylinder (33). The boom is hinged to the excavator body, the stick is hinged to the boom, the bucket is hinged to the stick, the boom cylinder body of the boom cylinder (1) is hinged to the excavator body, the boom piston rod of the boom cylinder (1) is hinged to the boom, the stick cylinder body of the stick cylinder (33) is hinged to the boom, the stick piston rod of the stick cylinder (33) is hinged to the stick, the bucket cylinder body of the bucket cylinder (2) is hinged to the stick, and the bucket piston rod of the bucket cylinder (2) is hinged to the bucket.

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