Excavator hydraulic system and excavator

Abstract

The present invention relates to the technical field of engineering vehicles, and in particular to an excavator hydraulic system and an excavator. The excavator hydraulic system includes a first main pump, a second main pump, a main valve, a confluence valve block, a priority valve, a confluence passage and a breaker; the confluence valve block is connected between the confluence passage and the first main pump, the second main pump is connected to the confluence passage and the main valve respectively through the priority valve, the confluence passage is arranged outside the main valve and communicates with the breaker; in the crushing operation mode, the priority valve can distribute the flow of the working oil supplied by the second main valve to the confluence passage and the main valve; when the confluence valve block is switched to the working state, the first main pump and the second main pump jointly supply oil to the breaker through the confluence passage; when the confluence valve block is switched to the non-working state, the second main pump alone supplies oil to the breaker through the confluence passage. The excavator includes the excavator hydraulic system. The excavator hydraulic system and the excavator avoid the occurrence of heating of the main valve and reduce pressure loss and heat loss.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering vehicles, and in particular to an excavator hydraulic system and an excavator. Background Art

[0002] Excavators are the main type of construction machinery, with the characteristics of high operating efficiency and good adaptability to working conditions. However, their technical problems of high fuel consumption and low energy utilization have never been effectively improved.

[0003] In the related art, the power element of the hydraulic system of an excavator usually includes two main pumps, and the control element mainly includes a main valve. In the crushing operation mode of the excavator, the main hydraulic actuator is a breaker hammer for realizing the crushing action. The two main pumps supply oil to the breaker hammer through the main valve, so that the hydraulic oil provided by the two main pumps first merges in the main valve and then is supplied to the breaker hammer. As a result, a lot of pressure will be lost in the main valve and a large amount of heat loss will be generated, resulting in the breaker hammer being unable to fully utilize the power provided by the two main pumps. Summary of the invention

[0004] The first purpose of the present invention is to provide an excavator hydraulic system to solve to a certain extent the technical problem that the excavator in the prior art will lose a lot of pressure in the main valve in the crushing operation mode, and generate a large amount of heat loss, resulting in the breaker hammer cannot fully utilize the power provided by the two main pumps.

[0005] The second purpose of the present invention is to provide an excavator to solve to a certain extent the technical problem that the excavator in the prior art will lose a lot of pressure in the main valve in the crushing operation mode, and generate a lot of heat loss, resulting in the breaker hammer cannot fully utilize the power provided by the two main pumps.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] Based on the above first purpose, the hydraulic system of an excavator provided by the present invention includes a first main pump, a second main pump, a main valve, a priority valve, a confluence valve block, a confluence passage and a breaker;

[0008] The merging valve block is connected between the merging passage and the first main pump, and the merging valve block includes a working state allowing the first main pump to supply oil to the merging passage and a non-working state preventing the first main pump from supplying oil to the merging passage;

[0009] The second main pump is communicated with the confluence passage and the main valve respectively through the priority valve;

[0010] The confluence passage is arranged outside the main valve and communicates with the breaker hammer;

[0011] In the crushing operation mode, the priority valve distributes the flow rate of the working oil supplied by the second main pump to the merging passage and the main valve;

[0012] When the confluence valve block is switched to a working state, the first main pump and the second main pump jointly supply oil to the breaker hammer through the confluence passage;

[0013] When the confluence valve block is switched to a non-operating state, the second main pump supplies oil to the breaker hammer through the confluence passage alone.

[0014] In any of the above technical solutions, optionally, the hydraulic system of the excavator further includes a pilot oil circuit and a crushing pilot valve, wherein the pilot oil circuit is connected to the crushing pilot valve and can supply oil to the crushing pilot valve;

[0015] The merging valve block comprises a merging valve and a solenoid valve, wherein the solenoid valve has two states, namely, disconnection and conduction, so as to disconnect and conduct the first control port of the crushing pilot valve and the merging valve;

[0016] When the oil pressure of the first control port reaches a first predetermined pressure, the merging valve switches to a first valve position formed by a one-way valve that only allows the first main pump to supply oil to the merging passage, so that the merging valve block is in a working state;

[0017] When the oil pressure of the first control port is less than the first predetermined pressure, the merging valve switches to a second valve position formed by two oppositely arranged one-way valves that do not allow the first main pump and the merging passage to supply oil to each other, so that the merging valve block is in a non-working state.

[0018] In any of the above technical solutions, optionally, the hydraulic system of the excavator further includes a pressure detection device;

[0019] The pressure detection device is communicated with the crushing pilot valve, and the pressure detection device can detect the oil pressure of the crushing pilot valve to determine the working state of the crushing hammer.

[0020] In any of the above technical solutions, optionally, the hydraulic system of the excavator further includes a proportional solenoid valve; the main valve further includes a main overflow valve;

[0021] The proportional solenoid valve is connected to the control port of the main relief valve and the pilot oil circuit to adjust the control pressure of the main relief valve according to the control current of the proportional solenoid valve.

[0022] In any of the above technical solutions, optionally, the proportional solenoid valve can control the control pressure of the main relief valve to a first control pressure so that the main valve is suitable for the excavation operation mode;

[0023] The proportional solenoid valve can control the control pressure of the main relief valve to a second control pressure, so that the main valve is suitable for a crushing operation mode.

[0024] In any of the above technical solutions, optionally, the hydraulic system of the excavator further includes a priority valve;

[0025] The main valve includes a first valve group that is normally connected to the first main pump and a second valve group that is connected to the second main pump through the priority valve.

[0026] In any of the above technical solutions, optionally, the second valve group is provided with a pilot oil port, and the pilot oil port establishes oil pressure according to a predetermined boom action instruction;

[0027] The priority valve is connected between the second main pump, the merging passage and the second valve group, and the priority valve includes a second control port communicating with the pilot oil port;

[0028] When the oil pressure of the second control port reaches a second predetermined pressure, the priority valve switches to a third valve position connecting the second main pump and the second valve group, so that the second main pump supplies oil to the second valve group;

[0029] When the oil pressure of the second control port does not reach the second predetermined pressure, the priority valve switches to a fourth valve position connecting the second main pump and the merging passage, so that the second main pump supplies oil to the merging passage.

[0030] In any of the above technical solutions, optionally, the predetermined boom action is boom lowering.

[0031] In any of the above technical solutions, optionally, the excavator hydraulic system further includes a safety valve, and the safety valve is connected to the second control port.

[0032] Based on the above second purpose, the excavator provided by the present invention includes the excavator hydraulic system provided by any of the above technical solutions.

[0033] By adopting the above technical solution, the beneficial effects of the present invention are:

[0034] The hydraulic system of an excavator provided by the present invention comprises a first main pump, a second main pump, a main valve, a confluence valve block, a priority valve, a confluence passage and a breaker. The confluence passage is arranged outside the main valve and is connected to the breaker; in the crushing operation mode, the second main pump can supply oil to the confluence passage, and when the confluence valve block is switched to the working state, the first main pump and the second main pump jointly supply oil to the breaker through the confluence passage, forming a dual-pump confluence mode; when the confluence valve block is switched to the non-working state, the second main pump alone supplies oil to the breaker through the confluence passage, forming a single-pump oil supply mode. In addition, in the crushing mode, the priority valve can control the flow distribution of the working oil supplied by the second main pump to the confluence passage and the main valve, so that the second main pump can temporarily and preferentially supply oil to the main valve in the crushing mode, so as to control the boom to preferentially perform the predetermined boom action through the main valve. Therefore, the hydraulic system of the excavator, on the one hand, can choose to adopt the dual-pump confluence mode or the single-pump oil supply mode according to the operating requirements of the breaker, thereby improving the flexibility of power distribution in the crushing operation mode; on the second hand, since the confluence path is located outside the main valve, it can prevent the working oil provided by the first main pump and the second main pump from entering the main valve and confluence in the main valve, thereby avoiding the occurrence of heating of the main valve, reducing the number of valves passing through the oil supply path, and reducing pressure loss and heat loss. Under the premise that the tonnage of the excavator is the same, compared with the solution of confluence in the valve, it can support the installation of a larger type of breaker, so that the excavator equipped with the hydraulic system of the excavator has a stronger crushing operation capability; on the third hand, by setting the priority valve, the boom can give priority to executing the predetermined boom action in the crushing operation mode, thereby making the functions of the excavator using the hydraulic system of the excavator more comprehensive and practical.

[0035] The excavator provided by the present invention includes the above-mentioned excavator hydraulic system, thereby being able to achieve all the beneficial effects of the excavator hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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.

[0037] Figure 1 A schematic diagram of the structure of an excavator hydraulic system provided in Embodiment 1 of the present invention;

[0038] Figure 2 A schematic diagram of a first state of an excavator hydraulic system provided in Embodiment 1 of the present invention;

[0039] Figure 3 A schematic diagram of a second state of the hydraulic system of an excavator provided in the first embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the third state of the excavator hydraulic system provided in the second embodiment of the present invention.

[0041] Icon: 301-first main pump; 302-second main pump; 303-solenoid valve; 304-merging valve; 3040-first control port; 305-priority valve; 3050-second control port; 306-first valve group; 307-second valve group; 3070-pilot oil port; 3071-main overflow valve; 308-breaking hammer; 309-breaking pilot valve; 310-proportional solenoid valve; 311-pressure detection device; 312-pilot pump; 313-safety valve; 314-merging passage. DETAILED DESCRIPTION

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0043] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0044] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0045] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation", "connection", and "connection" 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 connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0047] For ease of description, spatial relative terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the drawings. Such spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0048] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0049] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0050] Embodiment 1

[0051] See also Figures 1 to 4 As shown, this embodiment provides an excavator hydraulic system; Figure 1 A schematic diagram of the structure of the hydraulic system of the excavator provided in this embodiment; Figure 2 A schematic diagram of a first state of the hydraulic system of an excavator provided in this embodiment, that is, a schematic diagram of a state of the hydraulic system of an excavator in a single pump oil supply mode; Figure 3 A schematic diagram of a second state of the hydraulic system of the excavator provided in this embodiment, that is, a schematic diagram of the state of the hydraulic system of the excavator in a dual-pump confluence mode; Figure 4 The third state diagram of the hydraulic system of the excavator provided in this embodiment is a state diagram of the hydraulic system of the excavator in the excavation operation mode. Figures 2 to 4 The flow path of the working oil is shown by the thick solid line.

[0052] The excavator hydraulic system provided in this embodiment is used for an excavator, and the excavator has an excavation operation mode and a crushing operation mode in a working state.

[0053] See also Figures 1 to 4 As shown, the excavator hydraulic system provided in this embodiment includes a first main pump 301, a second main pump 302, a main valve, a confluence passage, a breaker 308, a priority valve 305, a safety valve 313, a pressure detection device 311, a proportional solenoid valve 310, a pilot pump 312 and a breaker pilot valve 309.

[0054] Hereinafter, the above components of the hydraulic system of the excavator will be described in detail.

[0055] In this embodiment, the first main pump 301 and the second main pump 302 are power elements of the hydraulic system of the excavator, and are used to supply oil to other components of the hydraulic system of the excavator. It can be understood that the number of the first main pump 301 and the second main pump 302 is at least one. The priority valve 305 corresponds to the second main pump 302 one by one, and the confluence valve block corresponds to the first main pump 301 one by one.

[0056] Further, it can be understood that the excavator hydraulic system may also include a third main pump that is only connected to the main valve and only supplies oil to the main valve.

[0057] During the construction process of the excavator, the breaker hammer 308 can break stones and rocks more effectively, thereby improving construction efficiency.

[0058] The first main pump 301 and the second main pump 302 are both connected to the main valve, which is usually also called a multi-way valve. The main valve determines the oil supply lines, oil supply methods, flow distribution and compound actions of the first main pump 301 and the second main pump 302 to each hydraulic action element of the excavator, and is an important component of the hydraulic system of the excavator. As an example, the main valve is connected to the boom cylinder to control the boom to complete the actions of rising and falling.

[0059] In this embodiment, in order to improve the synergistic effect of the main valve, the main valve includes a first valve group 306 and a second valve group 307. The first main pump 301 is always connected to the first valve group 306, and the second main pump 302 is connected to the second valve group 307 or the merging passage 314 through the priority valve 305. The merging passage 314 and the first main pump 301 are connected and disconnected by the merging valve block, and the merging passage 314 is used to supply oil to the breaker 308.

[0060] Based on the above structure, the hydraulic system of the excavator has an excavation operation mode and a crushing operation mode, and the crushing operation mode also includes a single pump oil supply mode and a double pump confluence mode.

[0061] In this embodiment, in the crushing operation mode:

[0062] The confluence valve block is connected between the confluence passage 314 and the first main pump 301, and the confluence valve block includes a working state that allows the first main pump 301 to supply oil to the confluence passage 314 and a non-working state that prevents the first main pump 301 from supplying oil to the confluence passage 314. Figure 2 As shown, when the confluence valve block is switched to the working state, the first main pump 301 and the second main pump 302 jointly supply oil to the breaker 308 through the confluence passage 314, forming a dual-pump confluence mode in the crushing operation mode; Figure 3 As shown, when the merging valve block is switched to the non-working state, the first main pump 301 is disconnected from the merging passage 314, and the second main pump 302 supplies oil to the breaker 308 alone through the merging passage 314, forming a single pump oil supply mode in the crushing operation mode.

[0063] Therefore, on the one hand, the hydraulic system of the excavator has two oil supply modes, namely, the double-pump confluence mode and the single-pump oil supply mode, to choose from in the crushing operation mode, which improves the diversity and rationality of the oil supply mode of the breaker 308 and is conducive to improving production efficiency. According to the crushing operation requirements, when the single-pump oil supply mode can meet the oil supply requirements of the breaker 308, the confluence valve block is kept in a non-working state and the single-pump oil supply mode is adopted; when the single-pump oil supply mode cannot meet the oil supply requirements of the breaker 308, the confluence valve block is switched to and kept in a working state and the double-pump oil supply mode is adopted.

[0064] On the other hand, since the merging passage 314 is arranged outside the main valve and connected to the breaker 308, no matter it is a single-pump oil supply mode or a dual-pump merging mode, the working oil of the first main pump 301 and the second main pump 302 can be delivered to the breaker 308 without passing through the main valve, and will not reach the breaker 308 after passing through multiple valves in the main valve, thereby reducing the pressure loss and heat loss in the main valve, reducing energy consumption, and being beneficial to energy saving and environmental protection.

[0065] In addition, since the working oil of the first main pump 301 and the second main pump 302 only passes through one valve to reach the breaker 308, the pressure loss and heat loss of the working oil in the transportation path are further reduced. Therefore, for excavators of the same tonnage, it can support the installation of a larger model of breaker 308, greatly improving the mechanical performance of the excavator.

[0066] In this embodiment, the pilot oil circuit is connected to the crushing pilot valve 309 to supply oil to the crushing pilot valve 309 , and the oil in the crushing pilot valve 309 is used as control oil to participate in the hydraulic control of the hydraulic system of the excavator. The pilot oil circuit is supplied with oil through the pilot pump 312 .

[0067] To facilitate the control of the timing of the switching state of the converging valve block, refer to Figure 1As shown, the confluence valve block includes a confluence valve 304 and a solenoid valve 303. The solenoid valve 303 has two states, namely, disconnection and conduction, to disconnect and conduct the crushing pilot valve 309 and the first control port of the confluence valve 304. The confluence valve 304 has a first valve position and a second valve position, and the execution of the valve position switching action of the confluence valve 304 is related to the oil pressure of the first control port 3040.

[0068] Specifically, when the solenoid valve 303 is energized, the solenoid valve 303 is in a conducting state, and the control oil of the crushing pilot valve 309 is supplied to the first control port 3040 through the solenoid valve 303 until the oil pressure of the first control port 3040 reaches the first predetermined pressure, and the merging valve 304 switches to the first valve position, and the first valve position is formed by a one-way valve allowing the first main pump 301 to supply oil to the merging passage 314, so that the first main pump 301 can supply oil to the merging passage 314, so that the merging valve block is in a working state, forming a dual-pump merging mode in the crushing operation mode, and preventing the merging passage 314 from flowing back to the second main pump 302.

[0069] When the solenoid valve 303 loses power, the solenoid valve 303 is in a disconnected state, and the control oil of the crushing pilot valve 309 cannot be supplied to the first control port 3040. Therefore, the oil pressure of the first control port 3040 is less than the first predetermined pressure, and the merging valve 304 switches to the second valve position. The second valve position is formed by two one-way valves that are relatively arranged and do not allow the first main pump 301 and the merging passage 314 to supply oil to each other, so that the first main pump 301 cannot supply oil to the merging passage 314, so that the merging valve block is in a non-working state, forming a single pump oil supply mode in the crushing operation mode, and can prevent the merging passage 314 from flowing back to the second main pump 302.

[0070] That is to say, by controlling the power on or off of the solenoid valve 303, the single pump oil supply mode and the double pump confluence mode can be conveniently and quickly switched in the crushing operation mode, thereby improving the working efficiency of the crushing operation. The power on and off state of the solenoid valve 303 can be controlled by a button in the cab or a remote control or other device, so that the operator can select and switch the crushing operation mode according to needs.

[0071] Optionally, in order to prevent the solenoid valve 303 from being in a power-off state, a one-way valve is formed by which the control oil is only allowed to move from the first control port 3040 to the direction of the crushing pilot valve 309 to form a valve position of the solenoid valve 303 for disconnecting the first control port 3040 and the crushing pilot valve 309, thereby preventing the control oil from the crushing pilot valve 309 from leaking to the first control port 3040 through the solenoid valve 303, thereby ensuring that the merging valve 304 can always be legally opened.

[0072] In this embodiment, in the crushing operation mode, it is usually the case that the boom is controlled by the main valve to preferentially execute the predetermined boom action. In this case, if the oil supply through the first main pump 301 which is normally connected to the main valve is usually insufficient to provide sufficient power, the second main pump 302 is required to supply oil to the main valve to provide sufficient power for the boom to preferentially execute the predetermined boom action.

[0073] In order to enable the second main pump 302 to supply oil to the main valve in the crushing operation mode, the excavator hydraulic system further includes a priority valve 305 .

[0074] Specifically, the second valve group 307 is provided with a pilot oil port 3070, which establishes oil pressure according to a predetermined boom action instruction. When the boom is required to preferentially perform a predetermined boom action, a predetermined boom action instruction is issued, and the pilot oil port 3070 starts to recommend pressure.

[0075] The second main pump 302 is connected to the merging passage 314 and the second valve group 307 respectively through the priority valve 305. In the crushing operation mode, the priority valve 305 can coordinately adjust the first opening of the second main pump 302 to supply oil to the merging passage 314 and the second opening of the second valve group 307 to control the flow distribution of the working oil supplied to the merging passage 314 and the second valve group 307. The coordinated adjustment of the first opening and the second opening of the priority valve 305 is controlled by the second control port 3050 of the priority valve 305. The second control port 3050 is connected to the pilot oil port 3070, so that the control oil pressure of the second control port 3050 is associated with the control oil pressure of the pilot oil port 3070.

[0076] When the pressure of the pilot oil port 3070 reaches the second predetermined pressure, it indicates that a predetermined boom action command has been issued, and thus the priority valve 305 performs an opening adjustment operation under the hydraulic control of the control oil of the second control port 3050, so that the priority valve 305 switches to and remains in the third valve position of preferentially supplying oil to the second valve group 307, that is, the first main pump 301 and the second main pump 302 jointly supply oil to the main valve, so that in the crushing operation mode, the predetermined boom action is preferentially executed.

[0077] When the predetermined boom action has been completed or does not need to be executed, the control oil pressure of the pilot oil port 3070 decreases and is less than the second predetermined pressure. The control oil pressure of the second control port 3050 of the priority valve 305 also decreases and is less than the second predetermined pressure. The priority valve 305 will perform the position change, i.e., the opening adjustment operation, again under the hydraulic control of the control oil of the second control port 3050, so that the priority valve 305 switches to and remains in the fourth valve position of giving priority to supplying oil to the confluence passage 314, i.e., the second main pump 302 supplies oil to the breaker 308, so that the breaker 308 performs the crushing operation normally in the crushing operation mode.

[0078] Therefore, by providing the priority valve 305 hydraulically controlled by the pilot oil port 3070, oil can be preferentially supplied to the second valve group 307 in the crushing operation mode, so as to realize the priority execution of the predetermined boom action and improve the flexibility of the working mode of the hydraulic system of the excavator.

[0079] In this embodiment, the predetermined boom action is boom lowering. In the crushing operation mode, the boom needs to be lowered frequently to achieve the purpose of making the breaker 308 press the working surface so that the crushing operation can be carried out reliably and efficiently. Therefore, the hydraulic system of the excavator supports the operation of giving priority to boom lowering in the crushing operation mode, and can smoothly cope with the working conditions of frequent boom lowering, thereby improving the efficiency of the crushing operation and making the excavator function using the hydraulic system of the excavator more comprehensive and practical.

[0080] In this embodiment, in order to improve the safety of the use of the priority valve 305, the hydraulic system of the excavator further includes a safety valve 313 connected to the second control port 3050 of the priority valve 305, so that when the control oil pressure of the pilot oil port 3070 is too high, the control oil pressure of the second control port 3050 can be kept within a safe range through the overflow effect of the safety valve 313. It can be understood that the set pressure of the safety valve 313 is determined according to the performance of the priority valve 305.

[0081] In this embodiment, in order to facilitate understanding of the current operating mode of the excavator hydraulic system, the excavator hydraulic system also includes a pressure detection device 311 connected to the crushing pilot valve 309. The pressure detection device 311 can detect the oil pressure of the crushing pilot valve 309 to determine the current operating mode of the excavator hydraulic system by judging the state of the breaker 308.

[0082] Specifically, when pressure is built up in the crushing pilot valve 309, it indicates that the machine is in the crushing operation mode. Optionally, when the oil pressure in the crushing pilot valve 309 reaches a first predetermined pressure, it indicates that the machine is in the dual-pump confluence mode. If the oil pressure in the crushing pilot valve 309 is lower than the first predetermined pressure, it indicates that the machine is in the single-pump oil supply mode. Of course, the oil pressure in the crushing pilot valve 309 can be the same in the dual-pump confluence mode and the single-pump confluence mode. When no pressure is built up in the crushing pilot valve 309, it indicates that the machine is in the excavation operation mode.

[0083] Optionally, the pressure detection device 311 is a pressure switch, and the on-off state of the pressure switch changes according to the detected oil pressure in the crushing pilot valve 309, so that the operator can understand the current operation mode of the excavator according to the state of the pressure switch. In order to further optimize the intuitiveness of the current operation mode prompt of the excavator, the pressure switch can be electrically connected to the indicator light.

[0084] In this embodiment, in the mining operation mode:

[0085] See also Figure 4 As shown, the solenoid valve 303 is switched to the disconnected state, and the confluence valve 304 is in the second valve position, so that the first main pump 301 only supplies oil to the first valve group 306 of the main valve; and supplies oil to the pilot oil port 3070, so that the priority valve 305 is switched to the third valve position, and the second main pump 302 supplies oil to the second valve group 307 of the main valve. In other words, the first main pump 301 and the second main pump 302 can jointly supply oil to the main pump to perform various driving operations in the excavation operation mode.

[0086] In order to ensure that the main valve can fully utilize the power provided by the first main pump 301 and the second main pump 302 in the excavation operation mode, a switch valve is set on the combined flow passage 314. By closing the switch valve in the excavation operation mode, the second main pump 302 can be blocked from supplying oil to the breaker 308, thereby achieving the effect of avoiding diversion of the breaker 308 in the excavation operation mode.

[0087] In this embodiment, in order to ensure the safety of the hydraulic system of the excavator, the main valve further includes a main relief valve 3071. The control pressure of the main relief valve 3071 determines the upper limit of the pressure of the main valve. In order to meet various operation requirements and safety under various operation requirements, the hydraulic system of the excavator further includes a proportional solenoid valve 310 connecting the control port of the main relief valve 3071 and the pilot pump 312. By adjusting the control current of the proportional solenoid valve 310, the control pressure of the main relief valve 3071 can be adjusted.

[0088] Specifically, in the excavation operation mode, the control current of the proportional solenoid valve 310 is the first control current, so that the opening of the proportional solenoid valve 310 is the first opening, and the control oil pressure provided by the pilot pump 312 to the control port of the main overflow valve 3071 is the first control pressure, so that the control pressure of the main overflow valve 3071 is controlled at the first control pressure, so that the main valve is suitable for the excavation operation mode.

[0089] In the crushing operation mode, the control current of the proportional solenoid valve 310 is the second control current, so that the opening of the proportional solenoid valve 310 is the second opening, and the pilot pump 312 provides the control oil pressure of the second control pressure to the control port of the main relief valve 3071, so that the control pressure of the main relief valve 3071 controls the second control pressure, so that the main valve is suitable for the crushing operation mode.

[0090] It is understandable that the first control current, the second control current, the first opening, the second opening, the first control pressure and the second control pressure can be adaptively adjusted according to the specific working environment, the tonnage of the excavator and the model and performance of the breaker 308.

[0091] Optionally, the proportional solenoid valve 310 is disposed outside the main valve to facilitate inspection and maintenance of the proportional solenoid valve 310 .

[0092] Embodiment 2

[0093] Embodiment 2 provides an excavator, which includes the excavator hydraulic system in Embodiment 1. The technical features of the excavator hydraulic system disclosed in Embodiment 1 are also applicable to this embodiment, and the technical features of the excavator hydraulic system disclosed in Embodiment 1 will not be described repeatedly.

[0094] Combination Figures 1 to 4 As shown, the excavator provided in this embodiment includes the excavator hydraulic system provided in the first embodiment.

[0095] The excavator in this embodiment has the advantages of the excavator hydraulic system in the first embodiment, and the advantages of the excavator hydraulic system disclosed in the first embodiment will not be described repeatedly here.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention is described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. In addition, those skilled in the art can understand that although some embodiments herein include certain features included in other embodiments instead of other features, the combination of features of different embodiments means being within the scope of the present invention and forming different embodiments. For example, any one of the claimed embodiments can be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. An excavator hydraulic system, characterized in that: It includes a first main pump, a second main pump, a main valve, a confluence valve block, a priority valve, a confluence passage and a breaker; The merging valve block is connected between the merging passage and the first main pump, and the merging valve block includes a working state allowing the first main pump to supply oil to the merging passage and a non-working state preventing the first main pump from supplying oil to the merging passage; The second main pump is communicated with the confluence passage and the main valve respectively through the priority valve; The confluence passage is arranged outside the main valve and communicates with the breaker hammer; In the crushing operation mode, the priority valve can distribute the flow rate of the working oil supplied by the second main pump to the merging passage and the main valve; When the confluence valve block is switched to a working state, the first main pump and the second main pump jointly supply oil to the breaker through the confluence passage; When the confluence valve block is switched to a non-working state, the second main pump supplies oil to the breaker hammer through the confluence passage alone; It also includes a pilot oil circuit and a crushing pilot valve, the pilot oil circuit is connected to the crushing pilot valve and can supply oil to the crushing pilot valve; the confluence valve block includes a confluence valve and a solenoid valve, the solenoid valve has two states of disconnection and conduction to disconnect and conduct the crushing pilot valve and the first control port of the confluence valve; when the oil pressure of the first control port reaches a first predetermined pressure, the confluence valve switches to a first valve position formed by a single valve that only allows the first main pump to supply oil to the confluence passage, so that the confluence valve block is in a working state; when the oil pressure of the first control port is less than the first predetermined pressure, the confluence valve switches to a second valve position formed by two one-way valves that are relatively arranged and do not allow the first main pump and the confluence passage to supply oil to each other, so that the confluence valve block is in a non-working state; The main valve includes a first valve group that is normally connected to the first main pump and a second valve group that is connected to the second main pump through the priority valve.

2. The hydraulic system for an excavator according to claim 1, characterized in that: Also included is a pressure detection device; The pressure detection device is communicated with the crushing pilot valve, and the pressure detection device can detect the oil pressure of the crushing pilot valve to determine the working state of the crushing hammer.

3. The hydraulic system for an excavator according to claim 1, characterized in that: It also includes a proportional solenoid valve; the main valve also includes a main overflow valve; The proportional solenoid valve is connected to the control port of the main relief valve and the pilot oil circuit to adjust the control pressure of the main relief valve according to the control current of the proportional solenoid valve.

4. The hydraulic system for an excavator according to claim 3, characterized in that: The proportional solenoid valve is capable of controlling the control pressure of the main relief valve to a first control pressure so that the main valve is suitable for an excavation operation mode; The proportional solenoid valve can control the control pressure of the main relief valve to a second control pressure, so that the main valve is suitable for a crushing operation mode.

5. The hydraulic system for an excavator according to claim 1, characterized in that: The second valve group is provided with a pilot oil port, and the pilot oil port establishes oil pressure according to a predetermined boom action instruction; The priority valve is connected between the second main pump, the merging passage and the second valve group, and the priority valve includes a second control port communicating with the pilot oil port; When the oil pressure of the second control port reaches a second predetermined pressure, the priority valve switches to a third valve position connecting the second main pump and the second valve group, so that the second main pump supplies oil to the second valve group; When the oil pressure of the second control port does not reach the second predetermined pressure, the priority valve switches to a fourth valve position connecting the second main pump and the merging passage, so that the second main pump supplies oil to the merging passage.

6. The hydraulic system for an excavator according to claim 5, characterized in that: The predetermined boom action is boom lowering.

7. The hydraulic system for an excavator according to claim 5, characterized in that: It also includes a safety valve, which is connected to the second control port.

8. An excavator, characterized in that: An excavator hydraulic system comprising any one of claims 1 to 7.

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