Hydraulic control system for construction machinery and construction machinery having the same

Abstract

The present invention provides a hydraulic control system of an engineering machinery and an engineering machinery having the same, wherein the hydraulic control system of the engineering machinery comprises: a first control valve, the first control valve comprises a first oil inlet, a first oil outlet, a first working oil port and a second working oil port; a second control valve, the second control valve comprises a second oil inlet, a second oil outlet, a third working oil port and a fourth working oil port; wherein the first working oil port and the third working oil port are suitable for being connected to a rodless cavity of a control cylinder of a working device, and the second working oil port and the fourth working oil port are suitable for being connected to a rod cavity of the control cylinder, the first control valve comprises a first gear position and a second gear position, and the second control valve comprises a third gear position and a fourth gear position. The technical solution of the present invention can recycle the gravitational potential energy generated when the working device descends, and at the same time solves the defect that the hydraulic system of the excavator in the prior art occupies a large space.

Description

Technical Field

[0001] The present invention relates to the technical field of excavator equipment, and in particular to a hydraulic control system of an engineering machine and an engineering machine having the same. Background Art

[0002] At present, most construction machinery transmissions are driven by hydraulics. Among them, hydraulic excavators realize excavation and unloading operations through single or compound actions of boom, dipper, bucket and rotation. The operator operates the pilot handle in the cab to switch the main valve spool, and the high-pressure oil pumped out by the oil pump is supplied to each working device, and the return oil from the working device is discharged to the oil tank. Under the current trend of electrification and intelligence, the requirements for energy saving and fuel consumption reduction of excavators are getting higher and higher, and the effective utilization rate of energy has become one of the important indicators for evaluating excavators. Since the working device of the excavator boom is very heavy, there is a problem of gravitational potential energy recovery when it is lowered after being lifted to the highest point. If it is not recovered, it will cause huge waste.

[0003] In order to solve the above technical problems, some excavators in the prior art store the gravitational potential energy when the boom is lowered by means of external valve blocks and accumulators. At the same time, the stored energy is released when the boom is raised or other working devices are working, thereby achieving the technical effect of recycling the potential energy generated when the excavator boom is lowered. However, the above technical solution requires the installation of valve blocks and accumulators in the hydraulic system, which makes the overall hydraulic system occupy a large space. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the hydraulic system of the excavator in the prior art occupies a large space, thereby providing a hydraulic control system of an engineering machinery and an engineering machinery having the same.

[0005] In order to solve the above problems, the present invention provides a hydraulic control system of an engineering machinery, comprising: a first control valve, the first control valve comprising a first oil inlet, a first oil outlet, a first working oil port and a second working oil port; a second control valve, the second control valve comprising a second oil inlet, a second oil outlet, a third working oil port and a fourth working oil port; wherein the first working oil port and the third working oil port are suitable for communicating with a rodless cavity of a control cylinder of a working device, and the second working oil port and the fourth working oil port are suitable for communicating with a rod cavity of the control cylinder, the first control valve comprises a first gear position and a second gear position, and the first control valve is in a first gear position When the first gear is in the first oil inlet, the first oil outlet is connected to the second working oil port, and the first oil outlet is connected to the second working oil port. When the first control valve is in the second gear, the first oil inlet is connected to the second working oil port, the first oil outlet is connected to the first working oil port, and the first working oil port is connected to the second working oil port. The second control valve includes a third gear and a fourth gear. When the second control valve is in the third gear, the second oil inlet is connected to the third working oil port, and the second oil outlet is connected to the fourth working oil port. When the second control valve is in the fourth gear, the third working oil port is connected to the second oil inlet, and the fourth working oil port is blocked from the second oil outlet.

[0006] Optionally, the second control valve further includes a fifth gear position. When the second control valve is in the fifth gear position, the second oil inlet, the second oil outlet, the third working oil port and the fourth working oil port are isolated from each other.

[0007] Optionally, the first control valve includes a first valve body and a first valve core arranged in the first valve body, the first oil inlet, the first oil outlet, the first working oil port and the second working oil port are all arranged on the first valve body, a first connecting passage is arranged in the first valve core, and a first connecting hole and a second connecting hole connected to the first connecting passage are arranged on the outer wall of the first valve core. The first valve core is configured so that when the first control valve is in the second gear, the first connecting hole corresponds to the first working oil port, and the second connecting hole corresponds to the second working oil port.

[0008] Optionally, a first one-way flow structure is provided in the first connecting channel, and the first one-way flow structure is suitable for allowing the hydraulic oil to flow in one direction from the first connecting hole to the second connecting hole.

[0009] Optionally, the second control valve includes a second valve body and a second valve core arranged in the second valve body, the second oil inlet, the second oil outlet, the third working oil port and the fourth working oil port are all arranged on the second valve body, a second connecting passage is arranged in the second valve core, and a third connecting hole and a fourth connecting hole connected to the second connecting passage are arranged on the outer wall of the second valve core. The second valve core is configured so that when the second control valve is in the fourth gear, the third connecting hole corresponds to the third working oil port, and the fourth connecting hole corresponds to the second oil inlet.

[0010] Optionally, a second one-way flow structure is provided in the second connecting channel, and the second one-way flow structure is suitable for allowing the hydraulic oil to flow in one direction from the third connecting hole to the fourth connecting hole.

[0011] Optionally, the construction machinery is an excavator, and the working device is the boom of the excavator.

[0012] Optionally, the hydraulic control system also includes a first oil supply device and a second oil supply device, the excavator also includes a boom, a bucket and a turntable, the first oil supply device includes a first oil supply circuit, the first oil supply circuit is connected to the first oil inlet, the control valve of the boom and the control valve of the bucket, the second oil supply device includes a second oil supply circuit, the second oil supply circuit is connected to the second oil inlet and the control valve of the turntable.

[0013] Optionally, the first oil supply circuit is connected to the second oil supply circuit, and a third one-way flow structure is provided on the first oil supply circuit and / or the second oil supply circuit, and the third one-way flow structure is suitable for allowing the hydraulic oil to flow one-way from the first oil supply device to the second oil supply device, or the third one-way flow structure is suitable for allowing the hydraulic oil to flow one-way from the second oil supply device to the first oil supply device.

[0014] The present invention also provides an engineering machine, comprising the above-mentioned hydraulic control system.

[0015] The present invention has the following advantages:

[0016] By using the technical solution of the present invention, when the working device needs to rise, the first control valve is in the first gear position, and the second control valve is in the third gear position. At this time, the hydraulic oil enters from the first oil inlet and the second oil inlet respectively, and enters into the rodless chamber of the driving oil cylinder along the first working oil port and the third working oil port, and the piston rod is extended to push the working device to rise. When the working device descends from a higher position, the first control valve is in the second gear position, and the second control valve is in the fourth gear position. At this time, part of the hydraulic oil in the rodless chamber enters into the first control valve. In the first control valve, part of the hydraulic oil flows back to the oil tank along the first working oil port and the first drain port, and the other part flows along the first working oil port and the second working oil port to the rod chamber of the driving oil cylinder for oil replenishment to prevent the working device from being stuck; another part of the hydraulic oil in the rodless chamber enters into the second control valve. In the second control valve, the hydraulic oil flows back to the main oil circuit along the third working oil port and the second oil inlet, thereby providing hydraulic power to other working devices, and playing the effect of recovering the gravitational potential energy generated when the working device descends. In the above structure, it is not necessary to set any valve block or accumulator. Only by changing the gear position of the first control valve and the second control valve, the rod chamber of the control oil cylinder can be replenished with oil when the working device is lowered, and the gravitational potential energy generated by the lowering can be collected and supplied to other working devices, which effectively reduces the space occupied by the hydraulic system. Therefore, the technical solution of the present invention can recycle the gravitational potential energy generated when the working device is lowered, and at the same time solves the defect of the hydraulic system of the excavator in the prior art that the space occupied is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a hydraulic control system for an engineering machine according to the present invention is shown;

[0019] Figure 2 Shows Figure 1 Schematic diagram of the first control valve of the hydraulic control system;

[0020] Figure 3 Shows Figure 1 Schematic diagram of the second control valve of the hydraulic control system;

[0021] Figure 4 Shows Figure 1 A schematic diagram of the internal structure of the first control valve of the hydraulic control system; and

[0022] Figure 5 Shows Figure 1 Schematic diagram of the internal structure of the second control valve of the hydraulic control system.

[0023] Description of reference numerals:

[0024] 10. First control valve; 11. First oil inlet; 12. First oil outlet; 13. First working oil port; 14. Second working oil port; 15. First valve body; 16. First valve core; 161. First connecting passage; 162. First connecting hole; 163. Second connecting hole; 164. First one-way flow structure; 20. Second control valve; 21. Second oil inlet; 22. Second oil outlet; 23. Third working oil port; 24. Fourth working oil port; 25. Second valve body; 26. Second valve core; 261. Second connecting passage; 262. Third connecting hole; 263. Fourth connecting hole; 264. Second one-way flow structure; 30. First oil supply device; 31. First oil supply oil circuit; 40. Second oil supply device; 41. Second oil supply oil circuit; 50. Dipper arm; 60. Bucket; 70. Control valve of turntable; 80. Third one-way flow structure. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] like Figures 1 to 3 As shown, the hydraulic control system of the engineering machinery of this embodiment includes: a first control valve 10 and a second control valve 20. The specific structure and arrangement of the first control valve 10 and the second control valve 20 are as follows:

[0030] The first control valve 10 includes a first oil inlet 11, a first oil outlet 12, a first working oil port 13, and a second working oil port 14. The first control valve 10 includes a first gear position and a second gear position. When the first control valve 10 is in the first gear position, the first oil inlet 11 is connected to the first working oil port 13, and the first oil outlet 12 is connected to the second working oil port 14. When the first control valve 10 is in the second gear position, the first oil inlet 11 is connected to the second working oil port 14, the first oil outlet 12 is connected to the first working oil port 13, and the first working oil port 13 is connected to the second working oil port 14.

[0031] The second control valve 20 includes a second oil inlet 21, a second oil outlet 22, a third working oil port 23 and a fourth working oil port 24. The second control valve 20 includes a third gear and a fourth gear. When the second control valve 20 is in the third gear, the second oil inlet 21 is connected to the third working oil port 23, and the second oil outlet 22 is connected to the fourth working oil port 24. When the second control valve 20 is in the fourth gear, the third working oil port 23 is connected to the second oil inlet 21, and the fourth working oil port 24 is blocked from the second oil outlet 22.

[0032] Furthermore, the first working oil port 13 and the third working oil port 23 are suitable for communicating with the rodless chamber of the control oil cylinder of the working device, and the second working oil port 14 and the fourth working oil port 24 are suitable for communicating with the rod chamber of the control oil cylinder.

[0033] By using the technical solution of this embodiment, when the working device needs to rise, the first control valve 10 is in the first gear position, and the second control valve 20 is in the third gear position. At this time, the hydraulic oil enters from the first oil inlet 11 and the second oil inlet 21 respectively, and enters the rodless chamber of the driving cylinder along the first working oil port 13 and the third working oil port 23, and the piston rod is extended to push the working device up. When the working device descends from a higher position, the first control valve 10 is in the second gear position, and the second control valve 20 is in the fourth gear position. At this time, part of the hydraulic oil in the rodless chamber enters the first control valve 10. In the first control valve 10, part of the hydraulic oil flows back to the oil tank along the first working oil port 13 and the first oil outlet, and the other part flows along the first working oil port 13 and the second working oil port 14 to the rod chamber of the driving cylinder for oil replenishment, so as to prevent the working device from getting stuck. Another part of the hydraulic oil in the rodless chamber enters the second control valve 20. In the second control valve 20, the hydraulic oil flows back to the main oil circuit along the third working oil port 23 and the second oil inlet 21, and can then provide hydraulic power to other working devices, thereby achieving the effect of recovering the gravitational potential energy generated when the working device descends. In the above structure, it is not necessary to set up any valve block or accumulator. Only by changing the gear position of the first control valve 10 and the second control valve 20 can the technical effect of replenishing oil to the rod chamber of the control cylinder when the working device descends, and collecting the gravitational potential energy generated by the descent and supplying it to other working devices be achieved, effectively reducing the space occupied by the hydraulic system. Therefore, the technical solution of this embodiment solves the defect that the hydraulic system of the excavator in the prior art occupies a large space.

[0034] It should be noted that the first control valve 10 and the second control valve 20 control the same driving cylinder, that is, the first working oil port 13 and the third working oil port 23 are connected to the rodless chamber of the same driving cylinder, and the second working oil port 14 and the fourth working oil port 24 are connected to the rod chamber of the same driving cylinder. Therefore, those skilled in the art can understand that when the working device rises, the first control valve 10 and the second control valve 20 simultaneously supply oil to the rodless chamber, thereby being able to drive the heavier working device to move upward. When the working device descends, part of the hydraulic oil in the control cylinder flows to the first control valve 10, and the other part flows to the second control valve 20. Combined with the above description, the first control valve 10 can make part of the hydraulic oil flow from the rodless chamber of the driving cylinder to the rod chamber, thereby achieving the oil replenishment effect. The second control valve 20 can collect the high-pressure hydraulic oil in the rodless chamber and supply it to other working devices, thereby achieving the effect of collecting the gravitational potential energy of the working device.

[0035] It should be noted that the above-mentioned working device refers to a component in an engineering machine that is driven by hydraulic pressure. Specifically in this embodiment, the working device is a boom in an excavator. Of course, other components in engineering machines that are driven by hydraulic pressure and move in the vertical direction are all within the scope of the above-mentioned "working device".

[0036] like Figure 2 As shown, in this embodiment, the first control valve 10 is a three-position four-way reversing valve. Figure 2 It can be seen that the first gear mentioned above is Figure 2 The upper position in the second gear is Figure 2 In addition, the first control valve 10 also includes a middle position, which is a cut-off position. When the first control valve 10 is in the middle position, the first oil inlet 11, the first oil outlet 12, the first working oil port 13 and the second working oil port 14 are isolated from each other. When the first control valve 10 is in the middle position, the position of the drive device can be locked. At this time, the drive cylinder can neither take in oil from the first control valve 10 nor return oil from the first control valve 10.

[0037] like Figure 3 As shown, in the technical solution of this example, the second control valve 20 also includes a fifth gear. When the second control valve 20 is in the fifth gear, the second oil inlet 21, the second oil outlet 22, the third working oil port 23 and the fourth working oil port 24 are isolated from each other. Figure 3 It can be seen that the second control valve 20 is also a three-position four-way reversing valve. Figure 3 The fourth gear mentioned above is also the lower position of Figure 3 Further, the fifth gear is Figure 3 The fifth gear is the middle position and the fifth gear is the cut-off gear. The fifth gear has two functions: 1. The fifth gear cooperates with the middle position of the first control valve 10 to lock the position of the working device; 2. When the working device is descending, if there is no need to recover the gravitational potential energy (that is, no other working device needs oil supply), the first control valve 10 is in the second gear and the second control valve 20 is in the fifth gear. At this time, only the first control valve 10 controls the control cylinder, and the second control valve 20 does not work (that is, no gravitational potential energy recovery is performed). By setting the fifth gear for the second control valve 20, the control method of the control cylinder is more diverse and more flexible.

[0038] Of course, those skilled in the art can understand that, for the control of the driving oil cylinder, the three gears of the first control valve 10 and the three gears of the second control valve 20 can be flexibly combined. For example, when only one control valve is needed to control the extension of the piston rod of the driving oil cylinder, the first control valve 10 can be in the first gear and the second control valve 20 can be in the fifth gear, or the first control valve 10 can be in the middle position and the second control valve 20 can be in the third gear. Those skilled in the art can flexibly adjust the gears of the first control valve 10 and the second control valve 20 according to actual work needs, and are not limited to the gear matching methods mentioned above.

[0039] like Figure 4 As shown, in the technical solution of the present embodiment, the first control valve 10 includes a first valve body 15 and a first valve core 16 arranged in the first valve body 15. Among them, the first oil inlet 11, the first oil outlet 12, the first working oil port 13 and the second working oil port 14 are all arranged on the first valve body 15. A first connecting channel 161 is arranged in the first valve core 16, and a first connecting hole 162 and a second connecting hole 163 connected to the first connecting channel 161 are arranged on the outer wall of the first valve core 16. Further, the first valve core 16 is configured so that when the first control valve 10 is in the second gear, the first connecting hole 162 corresponds to the first working oil port 13, and the second connecting hole 163 corresponds to the second working oil port 14. Specifically, the different gears of the above-mentioned first control valve 10, that is, the first valve core 16 is in different positions after moving in the first valve body 15. Combined with Figure 4 Those skilled in the art can understand that when the first control valve 10 is in the second gear, the first working oil port 13 and the first oil discharge port 12 are connected through the groove on the outer surface of the first valve core 16. At the same time, the hydraulic oil entering from the first working oil port 13 flows along the first connecting hole 162, the first connecting channel 161 and the second connecting hole 163 to the second working oil port 14, so that the hydraulic oil flows back to the rod chamber of the control oil cylinder for timely oil replenishment to prevent the phenomenon of air suction and jamming.

[0040] It should be noted that, combined with Figure 1 and Figure 4 Those skilled in the art can understand that when the first control valve 10 is in the first gear position or the middle position, the first connecting passage 161 does not serve to connect the two oil ports on the first valve body 15 .

[0041] like Figure 4As shown, in the technical solution of this embodiment, a first one-way flow structure 164 is provided in the first communication channel 161, and the first one-way flow structure 164 is suitable for allowing the hydraulic oil to flow in one direction from the first communication hole 162 to the second communication hole 163. Specifically, the first one-way flow structure 164 has a throttling effect on the hydraulic oil flowing through the first communication channel 161. Preferably, the first one-way flow structure 164 is a one-way valve.

[0042] like Figure 5 As shown, in the technical solution of this embodiment, the second control valve 20 includes a second valve body 25 and a second valve core 26 arranged in the second valve body 25. The second oil inlet 21, the second oil outlet 22, the third working oil port 23 and the fourth working oil port 24 are all arranged on the second valve body 25. A second connecting passage 261 is arranged in the second valve core 26, and a third connecting hole 262 and a fourth connecting hole 263 connected to the second connecting passage 261 are arranged on the outer wall of the second valve core 26. Furthermore, the second valve core 26 is configured so that when the second control valve 20 is in the fourth gear, the third connecting hole 262 corresponds to the third working oil port 23, and the fourth connecting hole 263 corresponds to the second oil inlet 21. Specifically, the different gears of the above-mentioned second control valve 20, that is, the second valve core 26 is in different positions after moving in the second valve body 25. Combined with Figure 5 Those skilled in the art can understand that when the first control valve 10 is in the second gear, the hydraulic oil in the rodless chamber of the control cylinder enters from the third working oil port 23, and then flows along the third connecting hole 262, the second connecting channel 261 and the fourth connecting hole 263 to the second oil inlet 21, so that the high-pressure hydraulic oil flows back to the main oil circuit, thereby providing driving force for other working devices. Figure 4 It can also be seen that a locking check valve is provided in the flow channel at the bottom of the second valve body 25, and the locking check valve is provided with a pilot oil port. When the second control valve 20 is in the fourth gear, the pilot oil lifts the locking check valve, thereby allowing the high-pressure hydraulic pressure to flow to the main oil circuit.

[0043] It should be noted that, combined with Figure 1 and Figure 5 Those skilled in the art can understand that when the second control valve 20 is in the third gear or the fifth gear, the second connecting passage 261 does not serve to connect the two oil ports on the second valve body 25 .

[0044] like Figure 5As shown, in the technical solution of this embodiment, a second one-way flow structure 264 is provided in the second communication channel 261, and the second one-way flow structure 264 is suitable for allowing the hydraulic oil to flow in one direction from the third communication hole 262 to the fourth communication hole 263. Specifically, the second one-way flow structure 264 has a throttling effect on the hydraulic oil flowing through the second communication channel 261. Preferably, the second one-way flow structure 264 is a one-way valve.

[0045] The above is the specific structure and working principle of the first control valve 10 and the second control valve 20 in the hydraulic control system. Other components in the hydraulic control system will be described below.

[0046] like Figure 1 As shown, the hydraulic control system further includes a first oil supply device 30 and a second oil supply device 40. The excavator further includes a boom 50, a bucket 60 and a slewing table. The first oil supply device 30 includes a first oil supply oil circuit 31, which is connected to the first oil inlet 11, the control valve of the boom 50 and the control valve of the bucket 60, and the second oil supply device 40 includes a second oil supply oil circuit 41, which is connected to the second oil inlet 21 and the control valve 70 of the slewing table. Specifically, the first oil supply device 30 and the second oil supply device 40 are two independent oil pumps, wherein the first oil supply device 30 supplies oil to the control cylinder of the boom (through the first control valve 10), the control cylinder of the boom 50 and the control cylinder of the bucket 60. The second oil supply device 40 can supply oil to the control cylinder of the boom (through the second control valve 20) and the control cylinder of the slewing table. In addition, those skilled in the art can understand that the hydraulic oil recovered by the second control valve 20 after the boom is lowered will flow into the second oil supply passage 41 .

[0047] like Figure 1 As shown, the first oil supply oil circuit 31 is connected with the second oil supply oil circuit 41, and the first oil supply oil circuit 31 and / or the second oil supply oil circuit 41 are provided with a third one-way flow structure 80, and the third one-way flow structure 80 is suitable for making the hydraulic oil flow from the first oil supply device 30 to the second oil supply device 40 in one direction, or the third one-way flow structure 80 is suitable for making the hydraulic oil flow from the second oil supply device 40 to the first oil supply device 30 in one direction. Specifically, in the above structure, there is a confluence between the first oil supply oil circuit 31 and the second oil supply oil circuit 41, and the third one-way flow structure 80 can make the hydraulic oil flow in one direction after the confluence, thereby improving the control diversity of different working devices in the excavator, and then selecting different control strategies.

[0048] Specifically in this embodiment, the third one-way flow structure 80 is a one-way valve, which can make the hydraulic oil in the second oil supply oil circuit 41 flow to the first oil supply oil circuit 31 and merge, so a variety of control strategies can be selected. For example, the second oil supply device 40 can not only supply oil to the driving cylinder of the boom and the control cylinder of the turntable through the second control valve 20, but also flow to the first oil supply oil circuit 31, and then supply oil to the driving cylinder of the control boom, the driving cylinder of the control stick 50, and the driving cylinder of the bucket 60 through the first control valve 10. In addition, the high-pressure hydraulic oil recovered by the second control valve 20 can also supply oil to the above-mentioned working device after passing through the second oil supply oil circuit 41 and the first oil supply oil circuit 31.

[0049] In combination with the various components in the above hydraulic control system, the following is an example of the specific control method of the hydraulic system:

[0050] 1. The boom is lowered alone: ​​the first control valve 10 is in the second gear position, and the second control valve 20 is in the fifth gear position;

[0051] 2. The boom is lowered alone, and other working devices are working: the first control valve 10 is in the second gear position, and the second control valve is in the fourth gear position;

[0052] 3. The boom rises and the turntable moves: the first oil supply device 30 controls the driving cylinder of the boom through the first control valve 10, and the second oil supply device 40 controls the driving cylinder of the turntable; or, the first oil supply device 30 controls the driving cylinder of the boom through the first control valve 10, and the second oil supply device 40 controls the driving cylinder of the turntable, and at the same time, the second oil supply device 40 controls the driving cylinder of the boom through the second control valve 20, and the flow is distributed between the second control valve 20 and the control valve 70 of the turntable through the priority valve;

[0053] 4. Boom rising, slewing table movement, and boom movement: the first oil supply device 30 controls the driving cylinder of the boom and the driving cylinder of the boom 50 through the first control valve 10, and the second oil supply device 40 controls the driving cylinder of the slewing table. At the same time, the second oil supply device 40 controls the driving cylinder of the boom through the second control valve 20, and the flow is distributed between the second control valve 20 and the control valve 70 of the slewing table through a priority valve.

[0054] also, Figure 1 The meanings of the nodes in the hydraulic system schematic diagram are as follows: Ba (Head) is the rodless cavity connection node of the boom control cylinder; Bb (Rod) is the rod cavity connection node of the boom control cylinder; WsA and WsB are the connection nodes of the drive cylinder of the turntable; T1 is the external oil tank connection node; Dr1-3 oil unloading connection node; Bm rege signal node. Therefore, those skilled in the art can combine Figure 1Be able to understand the hydraulic component symbols, the connection methods of each hydraulic component, and the meaning of each of the above nodes Figure 1 The complete operating principle of the hydraulic control system.

[0055] In combination with the above description, the hydraulic control system in this embodiment has the following advantages:

[0056] 1. When the boom is lowered, the first control valve 10 can regenerate the hydraulic oil from the rodless chamber through the first valve core 16 to the rod chamber, and the second control valve 20 can collect the hydraulic oil and supply it to other working devices, thereby improving the energy-saving and consumption-reducing performance of the excavator;

[0057] 2. By identifying the different loads of the excavator, different working device control strategies can be selected, thereby greatly reducing the excavator's fuel consumption and improving efficiency.

[0058] This embodiment also provides an engineering machine, which includes the above-mentioned hydraulic control system.

[0059] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A hydraulic control system for engineering machinery, characterized in that: include: A first control valve (10), the first control valve (10) comprising a first oil inlet (11), a first oil outlet (12), a first working oil port (13) and a second working oil port (14); A second control valve (20), the second control valve (20) comprising a second oil inlet (21), a second oil outlet (22), a third working oil port (23) and a fourth working oil port (24); The first working oil port (13) and the third working oil port (23) are suitable for communicating with the rodless chamber of the control oil cylinder of the working device, and the second working oil port (14) and the fourth working oil port (24) are suitable for communicating with the rod chamber of the control oil cylinder. The first control valve (10) includes a first gear position and a second gear position. When the first control valve (10) is in the first gear position, the first oil inlet (11) is connected to the first working oil port (13), and the first oil outlet (12) is connected to the second working oil port (14). When the first control valve (10) is in the second gear position, the first oil inlet (11) is connected to the second working oil port (14), the first oil outlet (12) is connected to the first working oil port (13), and the first working oil port (13) is connected to the second working oil port (14). The first control valve (10) also includes a cut-off gear position. When the first control valve (10) is in the cut-off gear position, the first oil inlet (11), the first oil outlet (12), the first working oil port (13) and the second working oil port (14) are isolated from each other. The second control valve (20) includes a third gear position and a fourth gear position. When the second control valve (20) is in the third gear position, the second oil inlet (21) is connected to the third working oil port (23), and the second oil outlet (22) is connected to the fourth working oil port (24). When the second control valve (20) is in the fourth gear position, the third working oil port (23) is connected to the second oil inlet (21), and the fourth working oil port (24) is isolated from the second oil outlet (22).

2. The hydraulic control system according to claim 1, characterized in that: The second control valve (20) further comprises a fifth gear position. When the second control valve (20) is in the fifth gear position, the second oil inlet (21), the second oil outlet (22), the third working oil port (23) and the fourth working oil port (24) are isolated from each other.

3. The hydraulic control system according to claim 1 or 2, characterized in that: The first control valve (10) comprises a first valve body (15) and a first valve core (16) arranged in the first valve body (15); the first oil inlet (11), the first oil outlet (12), the first working oil port (13) and the second working oil port (14) are all arranged on the first valve body (15); a first communication channel (161) is arranged in the first valve core (16); a first communication hole (162) and a second communication hole (163) which are in communication with the first communication channel (161) are arranged on an outer side wall of the first valve core (16); The first valve core (16) is configured such that, when the first control valve (10) is in the second gear position, the first communicating hole (162) corresponds to the first working oil port (13), and the second communicating hole (163) corresponds to the second working oil port (14).

4. The hydraulic control system according to claim 3, characterized in that: A first one-way flow structure (164) is provided in the first connecting channel (161), and the first one-way flow structure (164) is suitable for allowing the hydraulic oil to flow in one direction from the first connecting hole (162) to the second connecting hole (163).

5. The hydraulic control system according to claim 1 or 2, characterized in that: The second control valve (20) comprises a second valve body (25) and a second valve core (26) arranged in the second valve body (25); the second oil inlet (21), the second oil outlet (22), the third working oil port (23) and the fourth working oil port (24) are all arranged on the second valve body (25); a second communication passage (261) is arranged in the second valve core (26); a third communication hole (262) and a fourth communication hole (263) which are in communication with the second communication passage (261) are arranged on the outer side wall of the second valve core (26); The second valve core (26) is configured such that, when the second control valve (20) is in the fourth gear position, the third connecting hole (262) corresponds to the third working oil port (23), and the fourth connecting hole (263) corresponds to the second oil inlet port (21).

6. The hydraulic control system according to claim 5, characterized in that: A second one-way flow structure (264) is provided in the second connecting channel (261), and the second one-way flow structure (264) is suitable for allowing the hydraulic oil to flow in one direction from the third connecting hole (262) to the fourth connecting hole (263).

7. The hydraulic control system according to claim 1 or 2, characterized in that: The engineering machinery is an excavator, and the working device is the boom of the excavator.

8. The hydraulic control system according to claim 7, characterized in that: The hydraulic control system further comprises a first oil supply device (30) and a second oil supply device (40); the excavator further comprises a boom (50), a bucket (60) and a slewing table; the first oil supply device (30) comprises a first oil supply circuit (31); the first oil supply circuit (31) is connected to the first oil inlet (11), a control valve of the boom (50) and a control valve of the bucket (60); the second oil supply device (40) comprises a second oil supply circuit (41); the second oil supply circuit (41) is connected to the second oil inlet (21) and a control valve (70) of the slewing table.

9. The hydraulic control system according to claim 8, characterized in that: The first oil supply passage (31) is connected to the second oil supply passage (41), and a third one-way flow structure (80) is provided on the first oil supply passage (31) and / or the second oil supply passage (43). The third one-way flow structure (80) is suitable for allowing the hydraulic oil to flow one-way from the first oil supply device (30) to the second oil supply device (40), or the third one-way flow structure (80) is suitable for allowing the hydraulic oil to flow one-way from the second oil supply device (40) to the first oil supply device (30).

10. An engineering machine, characterized in that: Comprising the hydraulic control system according to any one of claims 1 to 9.

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