CN112196005A - Excavator hydraulic system and excavator - Google Patents

Abstract

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

Description

Excavator hydraulic system and excavator

Technical Field

The invention relates to the technical field of engineering vehicles, in particular to an excavator hydraulic system and an excavator.

Background

The excavator is a main power machine of engineering machinery, has the characteristics of high operation efficiency and good working condition adaptability, but the technical problems of high oil consumption and low energy utilization rate are not effectively improved all the time.

In the related art, the power element of the hydraulic system of the excavator generally includes two main pumps, the control element mainly includes a main valve, and in the crushing operation mode of the excavator, the main hydraulic actuator is a crushing hammer for performing a crushing operation, and the two main pumps supply oil to the crushing hammer through the main valve, so that hydraulic oil supplied by the two main pumps is merged in the main valve and then supplied to the crushing hammer, and thus a large amount of pressure is lost in the main valve, and a large amount of heat loss is generated, and the power supplied by the two main pumps cannot be fully utilized by the crushing hammer.

Disclosure of Invention

A first object of the present invention is to provide a hydraulic system for an excavator, which solves the technical problems of the excavator in the prior art that a large amount of pressure is lost in a main valve in a crushing operation mode, and a large amount of heat loss is generated, so that a crushing hammer cannot fully utilize power provided by two main pumps.

A second object of the present invention is to provide an excavator, which solves the technical problems of the excavator in the prior art that a large amount of pressure is lost in a main valve in a crushing operation mode, and a large amount of heat loss is generated, so that a crushing hammer cannot fully utilize power provided by two main pumps.

In order to achieve the above object, the present invention provides the following technical solutions;

in view of the above first object, the present invention provides an excavator hydraulic system including a first main pump, a second main pump, a main valve, a priority valve, a confluence valve block, a confluence passage, and a breaking hammer;

the confluence valve block is connected between the confluence passage and the first main pump, and includes an operating state in which the first main pump is allowed to supply oil to the confluence passage and a non-operating state in which the first main pump is prevented from supplying oil to the confluence passage;

the second main pump is communicated with the confluence passage and the main valve through the priority valve respectively;

the confluence passage is arranged outside the main valve and communicated with the breaking hammer;

in the crushing operation mode, the priority valve distributes the flow rate of the hydraulic oil supplied from 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 supply oil to the breaking hammer through the confluence passage together;

when the confluence valve block is switched to a non-working state, the second main pump supplies oil to the breaking hammer through the confluence passage alone.

In any of the above technical solutions, optionally, the excavator hydraulic system further includes a pilot oil path and a crushing pilot valve, where the pilot oil path is communicated with the crushing pilot valve and can supply oil to the crushing pilot valve;

the confluence valve block comprises a confluence valve and an electromagnetic valve, and the electromagnetic valve has a disconnection state and a conduction state so as to disconnect and conduct the crushing pilot valve and a first control port of the confluence valve;

when the oil pressure of the first control port reaches a first predetermined pressure, the confluence valve is switched to a first valve position formed by a check valve that allows only the first main pump to supply oil to the confluence passage, so that the confluence valve block is in an operating state;

when the oil pressure of the first control port is less than the first predetermined pressure, the confluence valve is switched to a second valve position formed by two check valves that are disposed opposite to each other 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-operating state.

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

the pressure detection device is communicated with the crushing pilot valve and can detect the oil pressure of the crushing pilot valve so as to judge the working state of the crushing hammer.

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

the proportional electromagnetic valve is communicated with a control port of the main overflow valve and the pilot oil way so as to adjust the control pressure of the main overflow valve according to the control current of the proportional electromagnetic valve.

In any of the above aspects, optionally, the proportional solenoid valve may control the control pressure of the main relief valve to a first control pressure to adapt the main valve to the excavation operation mode;

the proportional solenoid valve is capable of controlling the control pressure of the main spill valve to a second control pressure to adapt the main valve to a crushing mode of operation.

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

the main valve includes a first valve group in constant communication with the first main pump and a second valve group connected with the second main pump through the priority valve.

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;

the priority valve is connected among the second main pump, the confluence passage and the second valve group, and comprises a second control port communicated with the pilot oil port;

when the oil pressure of the second control port reaches a second preset pressure, the priority valve is switched to a third valve position for communicating the second main pump with 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 is switched to a fourth valve position that communicates the second main pump with the merging passage, so that the second main pump supplies oil to the merging passage.

In any of the above technical solutions, optionally, the predetermined boom movement is a boom lowering.

In any of the above solutions, optionally, the excavator hydraulic system further includes a relief valve, and the relief valve is communicated with the second control port.

In view of the second object, the excavator provided by the invention comprises the excavator hydraulic system provided by any one of the above technical schemes.

By adopting the technical scheme, the invention has the beneficial effects that:

the invention provides an excavator hydraulic system which comprises a first main pump, a second main pump, a main valve, a confluence valve block, a priority valve, a confluence passage and a breaking hammer. The confluence passage is arranged outside the main valve and is communicated with the breaking hammer; 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 a working state, the first main pump and the second main pump supply oil to the crushing hammer through the confluence passage together to form a double-pump confluence mode; when the confluence valve block is switched to a non-working state, the second main pump supplies oil to the breaking hammer through the confluence passage alone to form a single-pump oil supply mode. In the crushing mode, the priority valve can control the flow distribution of the hydraulic oil supplied from the second main pump to the merging passage and the main valve, so that the second main pump can temporarily supply the hydraulic oil preferentially to the main valve to control the boom to preferentially perform a predetermined boom operation by the main valve. Therefore, according to the hydraulic system of the excavator, on the first hand, a double-pump confluence mode or a single-pump oil supply mode can be selected according to the operation requirement of the breaking hammer, so that the flexibility of power distribution in the breaking operation mode is improved; in the second aspect, the confluence passage is positioned outside the main valve, so that the working oil provided by the first main pump and the second main pump can be prevented from entering the main valve and being converged in the main valve, the heating condition of the main valve is avoided, the number of valves passing through the oil supply path is reduced, the pressure loss and the heat loss are reduced, and compared with the scheme of confluence in the valve on the premise of the same tonnage of the excavator, the excavator provided with the hydraulic system of the excavator can support the installation of a breaking hammer with a larger model, so that the excavator provided with the excavator hydraulic system has stronger breaking operation capacity; in a third aspect, by providing a priority valve, the boom can preferentially execute a predetermined boom operation in the crushing operation mode, and the excavator to which the excavator hydraulic system is applied can be made more comprehensive and practical in function.

The excavator provided by the invention comprises the excavator hydraulic system, so that all the beneficial effects of the excavator hydraulic system can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of an excavator hydraulic system according to a first embodiment of the present invention;

fig. 2 is a schematic diagram illustrating a first state of an excavator hydraulic system according to a first embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a second state of the hydraulic system of the excavator according to the first embodiment of the invention;

fig. 4 is a schematic diagram of a third state of the excavator hydraulic system according to the second embodiment of the present invention.

Icon: 301-a first main pump; 302-a second main pump; 303-an electromagnetic valve; 304-a flow-combining valve; 3040-a first control port; 305-a priority valve; 3050-a second control port; 306-a first valve block; 307-a second valve block; 3070-leading oil port; 3071-main overflow valve; 308-breaking hammer; 309-a crushing pilot valve; 310-proportional solenoid valve; 311-pressure detection means; 312 — a pilot pump; 313-safety valve; 314-merging path.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are usually placed in when used, and are only used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements indicated must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

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

For ease of description, spatial relationship terms such as "above … …," "upper," "below … …," and "lower" may be used herein to describe one element's relationship to another element as illustrated in the figures. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular forms also are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shape that occur during manufacturing.

Example one

Referring to fig. 1 to 4, the present embodiment provides an excavator hydraulic system; fig. 1 is a schematic structural diagram of an excavator hydraulic system provided in this embodiment; fig. 2 is a schematic diagram of a first state of the excavator hydraulic system provided in the embodiment, namely a schematic diagram of a state of the excavator hydraulic system in a single-pump oil supply mode; fig. 3 is a schematic diagram of a second state of the excavator hydraulic system provided in the present embodiment, that is, a schematic diagram of a state of the excavator hydraulic system in a dual-pump confluence mode; fig. 4 is a schematic diagram of a third state of the excavator hydraulic system according to the present embodiment, that is, a schematic diagram of a state of the excavator hydraulic system in the excavation work mode. In fig. 2 to 4, the flow path of the working oil is shown by a thick solid line.

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

Referring to fig. 1 to 4, the excavator hydraulic system according to the present embodiment includes a first main pump 301, a second main pump 302, a main valve, a merging passage, a crushing hammer 308, a priority valve 305, a relief valve 313, a pressure detection device 311, a proportional solenoid valve 310, a pilot pump 312, and a crushing pilot valve 309.

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

In this embodiment, the first main pump 301 and the second main pump 302 are power elements of the excavator hydraulic system, and are used for supplying oil to other components of the excavator hydraulic system. It is understood that the number of the first and second main pumps 301 and 302 is at least one. The priority valves 305 correspond to the second main pumps 302 one to one, and the confluence valve blocks correspond to the first main pumps 301 one to one.

Further, it is understood that the excavator hydraulic system may further include a third main pump communicating with and supplying oil only to the main valve.

In the engineering construction process of the excavator, the breaking hammer 308 can more effectively break stones and rocks, thereby improving the construction efficiency.

The first main pump 301 and the second main pump 302 are both connected to a main valve, which is also commonly referred to as a multi-way valve, and which determines the oil supply lines, oil supply modes, flow distribution, compound actions and the like of the first main pump 301 and the second main pump 302 to each hydraulic acting element of the excavator, and is an important component of the excavator hydraulic system. As an example, a main valve is connected to a boom cylinder to control a boom to perform an operation such as raising and lowering.

In the present 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 normally communicated with the first valve group 306, the second main pump 302 is communicated with the second valve group 307 or the confluence passage 314 through the priority valve 305, and the make-and-break between the confluence passage 314 and the first main pump 301 is controlled by the confluence valve block, and the confluence passage 314 is used for supplying oil to the breaking hammer 308.

Based on the structure, the excavator hydraulic system has an excavation operation mode and a crushing operation mode, and the crushing operation mode further comprises a single-pump oil supply mode and a double-pump confluence mode.

In this embodiment, in the crushing operation mode:

the confluence valve block is connected between the confluence passage 314 and the first main pump 301, and includes an operating state in which the first main pump 301 is allowed to supply oil to the confluence passage 314 and a non-operating state in which the first main pump 301 is prevented from supplying oil to the confluence passage 314. As shown in fig. 2, when the confluence valve block is switched to an operating state, the first main pump 301 and the second main pump 302 supply oil to the breaking hammer 308 through the confluence passage 314 together, forming a dual-pump confluence mode in the breaking operation mode; as shown in fig. 3, when the confluence valve block is switched to the non-operating state, the first main pump 301 is disconnected from the confluence passage 314, and the second main pump 302 supplies oil to the breaking hammer 308 through the confluence passage 314 alone, thereby forming a single-pump oil supply mode in the breaking operation mode.

Therefore, on one hand, the hydraulic system of the excavator has two optional oil supply modes, namely a double-pump confluence mode and a single-pump oil supply mode, in the crushing operation mode, the diversity and the reasonability of the oil supply mode of the crushing hammer 308 are improved, and the production efficiency is improved. According to the requirement of crushing operation, when the oil supply requirement of the crushing hammer 308 can be met by the single-pump oil supply mode, 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 requirement of the breaking hammer 308, the confluence valve block is switched to and kept in a working state, and a double-pump oil supply mode is adopted.

On the other hand, since the merging passage 314 is provided outside the main valve and communicates with the hammer 308, the hydraulic oil of the first main pump 301 and the second main pump 302 can be delivered to the hammer 308 without passing through the main valve regardless of the single-pump oil supply mode or the double-pump merging mode, and does not reach the hammer 308 after passing through a plurality of valves in the main valve, thereby reducing pressure loss and heat loss in the main valve, reducing energy consumption, and contributing to energy saving and environmental protection.

In addition, the working oil of the first main pump 301 and the working oil of the second main pump 302 reach the breaking hammer 308 through only one valve, so that the pressure loss and the heat loss of the working oil in a conveying path are further reduced, and the larger type of breaking hammer 308 can be supported and installed for the excavator with the same tonnage, and the mechanical performance of the excavator is greatly improved.

In the present embodiment, the pilot oil passage communicates with the crushing pilot valve 309 to supply oil to the crushing pilot valve 309, and the oil liquid in the crushing pilot valve 309 participates in the hydraulic control of the excavator hydraulic system as the control oil. The pilot oil passage is supplied with oil by a pilot pump 312.

To facilitate control of the timing of switching the states of the confluence valve block, as shown in fig. 1, the confluence valve block includes a confluence valve 304 and a solenoid valve 303. Therein, the solenoid valve 303 has two states of off and on to turn off and on the first control port of the crushing pilot valve 309 and the confluence valve 304. The flow merging valve 304 has a first valve position and a second valve position, and the valve position switching operation of the flow merging valve 304 is performed in association with the oil pressure of the first control port 3040.

Specifically, when the electromagnetic valve 303 is energized, the electromagnetic valve 303 is in a conducting state, the control oil of the crushing pilot valve 309 is supplied to the first control port 3040 through the electromagnetic valve 303 until the oil pressure of the first control port 3040 reaches a first predetermined pressure, the confluence valve 304 is switched to a first valve position, which is formed by a one-way valve that allows the first main pump 301 to supply oil to the confluence passage 314, so that the first main pump 301 can supply oil to the confluence passage 314, the confluence valve block is in an operating state, a two-pump confluence mode is formed in the crushing operation mode, and the confluence passage 314 can be prevented from flowing back to the second main pump 302.

When the electromagnetic valve 303 is de-energized and the electromagnetic valve 303 is in the off state, the control oil of the crushing pilot valve 309 cannot be supplied to the first control port 3040, and therefore the oil pressure of the first control port 3040 is less than the first predetermined pressure, the confluence valve 304 is switched to the second valve position formed by two check valves that are disposed opposite to each other and do not allow the first main pump 301 and the confluence passage 314 to supply oil to each other, so that the first main pump 301 cannot supply oil to the confluence passage 314, so that the confluence valve block is in the non-operating state, a single-pump oil supply mode is formed in the crushing operation mode, and backflow of the confluence passage 314 to the second main pump 302 can be prevented.

That is to say, through the control of the power-on or power-off of the electromagnetic 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, and the working efficiency of the crushing operation is improved. The on-off state of the electromagnetic valve 303 can be controlled by a button in the cab or a remote controller or other equipment, so that an operator can select and switch the crushing operation mode according to the requirement.

Optionally, in order to avoid that the solenoid valve 303 is in the power-off state, the valve position of the solenoid valve 303 for disconnecting the first control port 3040 from the crushing pilot valve 309 is formed by a check valve that only allows the control oil to move from the first control port 3040 to the direction of the crushing pilot valve 309, thereby avoiding the situation that the crushing pilot valve 309 leaks the control oil to the first control port 3040 through the solenoid valve 303, so as to ensure that the flow combining valve 304 can be legally opened all the time.

In the present embodiment, in the crushing work mode, there is a case where the boom is controlled to preferentially perform the predetermined boom action through the main valve, and in this case, if the oil supply through the first main pump 301 normally connected to the main valve is not always sufficient to provide sufficient power, it is required that the second main pump 302 also supplies oil to the main valve to provide sufficient power for the boom to preferentially perform the predetermined boom action.

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

Specifically, the second valve group 307 is provided with a pilot port 3070, the pilot port 3070 establishes an oil pressure according to a predetermined boom action command, and when the boom is required to preferentially perform the predetermined boom action, the predetermined boom action command is issued, and the pilot port 3070 starts the recommended pressure.

The second main pump 302 communicates with the merging passage 314 and the second valve group 307 via the priority valve 305, and in the crushing operation mode, the priority valve 305 can control the flow rate distribution of the hydraulic oil supplied to the merging passage 314 and the second valve group 307 by adjusting a first opening degree at which the second main pump 302 supplies the hydraulic oil to the merging passage 314 and a second opening degree at which the hydraulic oil is supplied to the second valve group 307 in a coordinated manner. The cooperative adjustment of the first opening degree and the second opening degree of the priority valve 305 is controlled by the second control port 3050 of the priority valve 305. The second control port 3050 communicates with the pilot port 3070, thereby correlating the control oil pressure of the second control port 3050 with the control oil pressure of the pilot port 3070.

When the pressure at the pilot port 3070 reaches the second predetermined pressure, which indicates that the predetermined boom actuation command has been issued, the priority valve 305 performs the opening degree adjustment operation under the pilot control action of the control oil at the second pilot port 3050, so that the priority valve 305 is switched to and maintained at the third valve position where the oil is preferentially supplied to the second valve group 307, that is, the first main pump 301 and the second main pump 302 supply the oil to the main valve together, and the predetermined boom actuation is preferentially performed in the crushing operation mode.

When the predetermined boom action has been performed or is not required to be performed, the control oil pressure of the pilot port 3070 decreases to be less than the second predetermined pressure. The priority valve 305 is lowered in the pilot oil pressure at the second pilot port 3050 and becomes lower than the second predetermined pressure, and the priority valve 305 is shifted to and held at the fourth valve position where the pilot oil is supplied preferentially to the merging passage 314, that is, the second main pump 302 is supplied to the hammer 308, by the pilot operation of the pilot oil at the second pilot port 3050, that is, the opening degree adjustment operation is performed again, so that the hammer 308 is normally operated in the crushing operation mode.

Accordingly, by providing the priority valve 305 that is pilot-controlled by the pilot port 3070, it is possible to preferentially supply oil to the second valve group 307 in the crushing operation mode, thereby achieving preferential execution of a predetermined boom operation, and improving flexibility of the operation mode of the excavator hydraulic system.

In the present embodiment, since the boom movement is predetermined as the boom lowering, and it is necessary to frequently perform the boom lowering to press the breaking hammer 308 against the working surface in the breaking work mode, so that the breaking work can be performed reliably and efficiently, the excavator hydraulic system supports the operation in which the boom lowering is prioritized in the breaking work mode, and the frequent operating condition of the boom lowering can be smoothly coped with, thereby improving the breaking work efficiency and making the excavator to which the excavator hydraulic system is applied more comprehensive and practical.

In this embodiment, in order to improve the safety of use of the priority valve 305, the excavator hydraulic system further includes a relief valve 313 communicating with the second pilot port 3050 of the priority valve 305, so that when the control oil pressure at the pilot port 3070 is too high, the control oil pressure at the second pilot port 3050 can be maintained within a safe range by the relief action of the relief valve 313. It will be appreciated that the set pressure of the relief valve 313 is determined based on the performance of the priority valve 305.

In this embodiment, in order to facilitate understanding of the current operation mode of the excavator hydraulic system, the excavator hydraulic system further includes a pressure detection device 311 communicated with the crushing pilot valve 309, and the pressure detection device 311 can detect the oil pressure of the crushing pilot valve 309 to determine the current operation mode of the excavator hydraulic system by determining the state of the crushing hammer 308.

Specifically, when pressure is built up in the crushing pilot valve 309, it is indicated that the crushing operation mode is in. Wherein, optionally, when the oil pressure in the crushing pilot valve 309 reaches a first predetermined pressure, it is indicated to be in the dual-pump confluence mode, and if the oil pressure in the crushing pilot valve 309 is lower than the first predetermined pressure, it is indicated to be in the single-pump oil supply mode; of course, the hydraulic pressure in the crushing pilot valve 309 may be the same in the two-pump merge mode and the single-pump merge mode. When the pressure is not built in the crushing pilot valve 309, it indicates that the excavation operation mode is in use.

Alternatively, 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 know the current work mode of the excavator according to the state of the pressure switch. In order to further optimize the intuitiveness of the prompt of the current operation mode of the excavator, the pressure switch can be electrically connected with the indicator lamp.

In the present embodiment, in the excavation work mode:

referring to fig. 4, the solenoid valve 303 is switched to the off state, and the confluence valve 304 is in the second valve position, so that the first main pump 301 supplies oil only to the first valve group 306 of the main valves; the second main pump 302 supplies oil to the second valve group 307 of the main valve by switching the priority valve 305 to the third valve position by supplying oil to the pilot port 3070. That is, the first main pump 301 and the second main pump 302 can supply oil to the main pumps in common, and thus various driving operations in the excavation work mode can be performed.

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, the switching valve is arranged on the confluence passage 314, and the switching valve is closed in the excavation operation mode, so that the oil supply of the second main pump 302 to the breaking hammer 308 can be blocked, and the effect of avoiding the shunting of the breaking hammer 308 in the excavation operation mode is achieved.

In the present embodiment, in order to ensure the safety of use of the excavator hydraulic system, the main valve further includes a main relief valve 3071. The control pressure of the main relief valve 3071 determines the upper pressure limit of the main valve, and in order to satisfy various work demands and safety under various work demands, the excavator hydraulic system further includes a proportional solenoid valve 310 that communicates the control port of the main relief valve 3071 with the pilot pump 312, and the control pressure of the main relief valve 3071 can be adjusted by adjusting the control current of the proportional solenoid valve 310.

Specifically, in the excavation operation mode, the control current of the proportional solenoid valve 310 is the first control current, so that the opening degree of the proportional solenoid valve 310 is the first opening degree, and the control oil pressure supplied to the control port of the main relief valve 3071 by the pilot pump 312 is the first control pressure, so that the control pressure of the main relief valve 3071 is controlled to the first control pressure, so that the main valve is suitable for the excavation operation mode.

In the crushing operation mode, the control current of the proportional solenoid valve 310 is the second control current, so that the opening degree of the proportional solenoid valve 310 is the second opening degree, and the pilot pump 312 supplies the control oil pressure to the control port of the main relief valve 3071 as the second control pressure, so that the control pressure of the main relief valve 3071 is controlled to the second control pressure, so that the main valve is suitable for the crushing operation mode.

It can be understood that, with different specific working environments, different tonnage of the excavator and different types and performances of the breaking hammer 308, the first control current, the second control current, the first opening degree, the second opening degree, the first control pressure and the second control pressure can be adaptively adjusted accordingly.

Optionally, the proportional solenoid valve 310 is disposed outside of the main valve to facilitate servicing and maintenance of the proportional solenoid valve 310.

Example two

The second embodiment provides an excavator, the excavator in the first embodiment comprises the excavator hydraulic system, the technical features of the excavator hydraulic system disclosed in the first embodiment are also applicable to the first embodiment, and the technical features of the excavator hydraulic system disclosed in the first embodiment are not described repeatedly.

With reference to fig. 1 to 4, the excavator provided in the present embodiment includes an excavator hydraulic system provided in the first embodiment.

The excavator in the 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 are not described repeatedly herein.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention. Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Claims (10)

1. The hydraulic system of the excavator is characterized by comprising a first main pump, a second main pump, a main valve, a confluence valve block, a priority valve, a confluence passage and a breaking hammer;

the confluence valve block is connected between the confluence passage and the first main pump, and includes an operating state in which the first main pump is allowed to supply oil to the confluence passage and a non-operating state in which the first main pump is prevented from supplying oil to the confluence passage;

the second main pump is communicated with the confluence passage and the main valve through the priority valve respectively;

the confluence passage is arranged outside the main valve and communicated with the breaking hammer;

in the crushing operation mode, the priority valve may distribute a flow rate of the hydraulic oil supplied from 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 supply oil to the breaking hammer through the confluence passage together;

when the confluence valve block is switched to a non-working state, the second main pump supplies oil to the breaking hammer through the confluence passage alone.

2. The excavator hydraulic system of claim 1 further comprising a pilot oil passage and a crushing pilot valve, the pilot oil passage being in communication with and capable of supplying oil to the crushing pilot valve;

the confluence valve block comprises a confluence valve and an electromagnetic valve, and the electromagnetic valve has a disconnection state and a conduction state so as to disconnect and conduct the crushing pilot valve and a first control port of the confluence valve;

when the oil pressure of the first control port reaches a first predetermined pressure, the confluence valve is switched to a first valve position formed by a check valve that allows only the first main pump to supply oil to the confluence passage, so that the confluence valve block is in an operating state;

when the oil pressure of the first control port is less than the first predetermined pressure, the confluence valve is switched to a second valve position formed by two check valves that are disposed opposite to each other 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-operating state.

3. The excavator hydraulic system of claim 2 further comprising a pressure sensing device;

the pressure detection device is communicated with the crushing pilot valve and can detect the oil pressure of the crushing pilot valve so as to judge the working state of the crushing hammer.

4. The excavator hydraulic system of claim 2 further comprising a proportional solenoid valve; the main valve also comprises a main overflow valve;

the proportional electromagnetic valve is communicated with a control port of the main overflow valve and the pilot oil way so as to adjust the control pressure of the main overflow valve according to the control current of the proportional electromagnetic valve.

5. The excavator hydraulic system of claim 4,

the proportional solenoid valve is capable of controlling the control pressure of the main relief valve to a first control pressure to adapt the main valve to an excavation operation mode;

the proportional solenoid valve is capable of controlling the control pressure of the main spill valve to a second control pressure to adapt the main valve to a crushing mode of operation.

6. The excavator hydraulic system of claim 1 further comprising a priority valve;

the main valve includes a first valve group in constant communication with the first main pump and a second valve group connected with the second main pump through the priority valve.

7. The excavator hydraulic system of claim 6,

the second valve group is provided with a pilot oil port, and the pilot oil port establishes oil pressure according to a preset movable arm action instruction;

the priority valve is connected among the second main pump, the confluence passage and the second valve group, and comprises a second control port communicated with the pilot oil port;

when the oil pressure of the second control port reaches a second preset pressure, the priority valve is switched to a third valve position for communicating the second main pump with 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 is switched to a fourth valve position that communicates the second main pump with the merging passage, so that the second main pump supplies oil to the merging passage.

8. The excavator hydraulic system of claim 7 wherein the predetermined boom action is boom lowering.

9. The excavator hydraulic system of claim 7 further comprising a relief valve in communication with the second control port.

10. An excavator comprising an excavator hydraulic system as claimed in any one of claims 1 to 9.

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