Energy-saving device suitable for hydraulic excavator

Abstract

The utility model provides an energy-saving device suitable for a hydraulic excavator. The energy-saving device comprises a shuttle valve, a first electromagnetic directional valve, a second electromagnetic directional valve, a first cartridge valve and a second cartridge valve, a first oil port and a second oil port are formed in the first cartridge valve; a fourth oil port and a fifth oil port are formed in the second cartridge valve; when the first electromagnetic directional valve is located at the left working position and the right working position respectively, a spring cavity of the first cartridge valve is communicated with the first oil port and the second oil port respectively; when the second electromagnetic directional valve is located at the left working position and the right working position, a spring cavity of the second cartridge valve is communicated with the fourth oil port and an outlet of the shuttle valve respectively; two inlets of the shuttle valve are respectively connected with a fourth oil port and a fifth oil port; the second oil port and the fifth oil port are both communicated with the third oil port; the first oil port is connected with a rodless cavity of the hydraulic excavator boom cylinder, the fourth oil port is connected with a rod cavity of the hydraulic excavator boom cylinder, and the third oil port is connected with the energy accumulator. The energy recovery device can realize the energy recovery of the movable arm of the liquid excavator.

Description

Technical Field

[0001] This application belongs to the technical field of construction machinery, and particularly relates to an energy-saving device applicable to a hydraulic excavator. Background Art

[0002] In the field of construction machinery, hydraulic excavators have been widely used. However, their energy consumption is relatively large. Therefore, it is imperative to reduce energy consumption and emissions of excavators. At present, the recovery of the potential energy of the boom of a hydraulic excavator has become an important breakthrough. In addition, certain achievements have been made in the research of hybrid power. To reduce the working energy consumption of an excavator, more and more attention has been paid to the research on the energy recovery and reuse of the boom and arm of the excavator.

[0003] Almost all operation types of an excavator involve the actions of lifting and lowering the boom. To ensure the working reliability of the working mechanism of a hydraulic excavator, the design weight of the working device is generally very large. When the boom of the excavator is lifted, hydraulic energy is converted into gravitational potential energy. When it is lowered, the gravitational potential energy is converted into hydraulic energy through the hydraulic cylinder and then dissipated as heat through the throttle orifices of the hydraulic system.

[0004] Most of the energy during the lowering of the boom is not only wasted through heat generation, but also causes the temperature of the hydraulic oil to rise rapidly, requiring a dedicated cooling device for cooling, further increasing the system power consumption. Utility Model Content

[0005] The utility model aims to provide an energy-saving device applicable to a hydraulic excavator, which can realize the energy recovery of the boom of the hydraulic excavator.

[0006] The technical solution provided by this application is as follows:

[0007] An energy-saving device applicable to a hydraulic excavator, comprising: a shuttle valve, a first electromagnetic directional control valve, a second electromagnetic directional control valve, a first cartridge valve and a second cartridge valve;

[0008] A first oil port and a second oil port are provided on the first cartridge valve; a fourth oil port and a fifth oil port are provided on the second cartridge valve;

[0009] The working positions of the first electromagnetic directional control valve and the second electromagnetic directional control valve both include a left working position and a right working position; the first electromagnetic directional control valve and the second electromagnetic directional control valve switch working positions according to the boom movement signal of the hydraulic excavator;

[0010] The first electromagnetic directional control valve responds to the boom rising signal and switches to the left working position; when the first electromagnetic directional control valve is in the left working position, the spring chamber of the first cartridge valve is communicated with the first oil port through the first electromagnetic directional control valve; when the first electromagnetic directional control valve is in the right working position, the spring chamber of the first cartridge valve is communicated with the second oil port through the first electromagnetic directional control valve; the second oil port is communicated with the third oil port;

[0011] The second electromagnetic directional control valve responds to the boom lowering signal and switches to the left working position; when the second electromagnetic directional control valve is in the left working position, the spring chamber of the second cartridge valve is communicated with the fourth oil port through the second electromagnetic directional control valve; when the second electromagnetic directional control valve is in the right working position, the spring chamber of the second cartridge valve is communicated with the outlet of the shuttle valve through the second electromagnetic directional control valve; the two inlets of the shuttle valve are respectively connected to the fourth oil port and the fifth oil port; the fifth oil port is communicated with the third oil port;

[0012] The first oil port is connected to the rodless chamber of the boom cylinder of the hydraulic excavator, the fourth oil port is connected to the rod chamber of the boom cylinder of the hydraulic excavator, and the third oil port is connected to the accumulator.

[0013] In some possible implementation manners, the second oil port and the fifth oil port are connected.

[0014] In some possible implementation manners, the energy-saving device further includes a plate-type ball valve. The inlet of the plate-type ball valve is communicated with the third oil port, the second oil port and the fifth oil port, and the outlet of the plate-type ball valve is communicated with the fuel tank.

[0015] In some possible implementation manners, the energy-saving device further includes a relief valve. The inlet of the relief valve is communicated with the third oil port, the second oil port and the fifth oil port, and the outlet of the relief valve is communicated with the fuel tank.

[0016] In some possible implementation manners, the energy-saving device further includes a first pressure detector installed in the pipeline where the second oil port and the fifth oil port are connected.

[0017] In some possible implementation manners, the energy-saving device further includes a second pressure detector and a third pressure detector, which are respectively installed in the rodless chamber of the boom cylinder and the rod chamber of the boom cylinder.

[0018] Beneficial effects:

[0019] This application can convert the gravitational potential energy during the lowering process of the boom of the hydraulic excavator into hydraulic energy for storage and then feedback it to the system. Description of the drawings

[0020] Figure 1 It is a schematic structural diagram of an embodiment of this application. Specific implementation manners

[0021] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this application.

[0022] It should be noted that terms such as "first" and "second" in the description and claims of this application and the above-mentioned drawings are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply a specific relationship or order between these entities or operations. It should be understood that the words "first" and "second" do not limit the quantity and execution order, and the words "first" and "second" do not necessarily limit being different. It should be understood that such used data can be interchanged under appropriate circumstances. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those clearly listed elements, but may also include other elements not clearly listed, or may also include elements inherent to such process, method, product or device. Without more limitations, the element defined by the statement "including one..." does not exclude the existence of other identical elements in the process, method, article or device including the said element.

[0023] In this application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0024] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0025] In addition, the terms "installed", "set up", "provided with", "connected", "communicated with", "socketed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct communication, or an indirect communication through an intermediate medium, or an internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] Next, specific embodiments according to this application will be described with reference to Figure 1 the following.

[0027] As Figure 1 shown, this application discloses an energy-saving device applicable to a hydraulic excavator, including: a shuttle valve, a first electromagnetic directional valve EW5, a second electromagnetic directional valve EW6, a first cartridge valve LC1 and a second cartridge valve LC2;

[0028] The first cartridge valve LC1 is provided with a first oil port A and a second oil port; the second cartridge valve LC2 is provided with a fourth oil port B and a fifth oil port;

[0029] The working positions of the first electromagnetic directional valve EW5 and the second electromagnetic directional valve EW6 both include a left working position and a right working position; the first electromagnetic directional valve EW5 and the second electromagnetic directional valve EW6 switch working positions according to the boom movement signal of the hydraulic excavator;

[0030] The first electromagnetic directional valve EW5 responds to the boom rising signal and switches to the left working position; when the first electromagnetic directional valve EW5 is in the left working position, the spring chamber of the first cartridge valve LC1 is communicated with the first oil port A through the first electromagnetic directional valve EW5; when the first electromagnetic directional valve EW5 is in the right working position, the spring chamber of the first cartridge valve LC1 is communicated with the second oil port through the first electromagnetic directional valve EW5; the second oil port is communicated with the third oil port K;

[0031] The second electromagnetic directional valve EW6 responds to the boom lowering signal and switches to the left working position; when the second electromagnetic directional valve EW6 is in the left working position, the spring chamber of the second cartridge valve LC2 is communicated with the fourth oil port B through the second electromagnetic directional valve EW6; when the second electromagnetic directional valve EW6 is in the right working position, the spring chamber of the second cartridge valve LC2 is communicated with the outlet of the shuttle valve through the second electromagnetic directional valve EW6; the two inlets of the shuttle valve are respectively connected to the fourth oil port B and the fifth oil port; the fifth oil port is communicated with the third oil port K;

[0032] The first oil port A is connected to the rodless cavity of the boom cylinder of the hydraulic excavator, the fourth oil port B is connected to the rod chamber of the boom cylinder of the hydraulic excavator, and the third oil port K is connected to the accumulator.

[0033] In some embodiments, the second oil port and the fifth oil port are connected. Thus, there is an oil passage communication between the first cartridge valve LC1 and the second cartridge valve LC2.

[0034] In some embodiments, the energy-saving device further includes a plate-type ball valve CB1. The inlet of the plate-type ball valve CB1 is communicated with the third oil port K, the second oil port of the first cartridge valve LC1, and the fifth oil port of the second cartridge valve LC2. The outlet of the plate-type ball valve CB1 is communicated with the tank T port. Among them, the plate-type ball valve CB1 can be manually opened to allow the excess hydraulic oil in the accumulator, the first cartridge valve LC1, or the second cartridge valve LC2 to flow to the tank, releasing the pressure of the accumulator, the first cartridge valve LC1, and the second cartridge valve LC2.

[0035] In some embodiments, the energy-saving device further includes a relief valve Re. The inlet of the relief valve Re is communicated with the third oil port K, the second oil port of the first cartridge valve LC1, and the fifth oil port of the second cartridge valve LC2. The outlet of the relief valve Re is communicated with the tank T port. The relief valve Re opens in response to the working pressure of the accumulator, the first cartridge valve LC1, or the second cartridge valve LC2 being greater than the safety value, allowing the excess hydraulic oil in the accumulator, the first cartridge valve LC1, or the second cartridge valve LC2 to flow to the tank, releasing the pressure of the accumulator, the first cartridge valve LC1, and the second cartridge valve LC2.

[0036] In some embodiments, the energy-saving device further includes a first pressure detector installed in the pipeline where the second oil port and the fifth oil port are connected, for detecting the pressure in this pipeline.

[0037] In some embodiments, the energy-saving device further includes a second pressure detector and a third pressure detector, which are respectively installed in the rodless cavity and the rod cavity of the boom cylinder, and are respectively used for detecting the pressure in the rodless cavity and the rod cavity of the boom cylinder.

[0038] As Figure 1 shown, where the M1 port is used to read the pressure in the rodless cavity of the boom cylinder, the M2 port is used to read the pressure in the rod cavity of the boom cylinder, and the M port is used to read the internal working pressure of the valve body.

[0039] The working principle of the above embodiments of the present application will be described below.

[0040] The first electromagnetic directional control valve EW5 and the first cartridge valve LC1 form a first two-position two-way check valve, which can block the second oil port (connected to the third oil port K of the bucket) from leading to the first oil port A or block the first oil port A from leading to the second oil port. When the boom rises, the hydraulic oil flows from the third oil port K through the second oil port of the first cartridge valve LC1, pushing the first cartridge valve LC1 to open and flowing to the first oil port A. At this time, receiving the boom rising signal, the first electromagnetic directional control valve EW5 is in the left working position (energized position), and the spring chamber (X chamber, pilot oil port) of the first cartridge valve LC1 is connected to the first oil port A, blocking the hydraulic oil from flowing from the first oil port A to the second oil port (the hydraulic oil cannot return from the first oil port A to the third oil port K. Thus, the hydraulic oil in the accumulator is fed back to the system through the third oil port K); when the boom descends, the hydraulic oil pushes the first cartridge valve LC1 to open from the first oil port A, flows through the first cartridge valve LC1 to the third oil port K / relief valve Re / and then flows to the fourth oil port B through the second cartridge valve LC2 to achieve energy recovery / pressure relief / feedback to the system. At this time, the first electromagnetic directional control valve EW5 is in the right working position (non-energized position), and the spring chamber of the first cartridge valve LC1 is connected to the second oil port through the first electromagnetic directional control valve EW5, and the hydraulic oil cannot flow back from the second oil port to the first oil port A through the first cartridge valve LC1.

[0041] The second electromagnetic directional control valve EW6, the second cartridge valve LC2 and the shuttle valve form a second two-position two-way check valve, which can block the fifth oil port (connected to the third oil port K) from leading to the fourth oil port B and the fourth oil port B from leading to the fifth oil port at the same time, or only block the fourth oil port B from leading to the fifth oil port. When the boom rises, at this time the second electromagnetic directional control valve EW6 is in the right working position (non-energized position), and the fifth oil port is connected to the spring chamber of the second cartridge valve LC2 through the shuttle valve and the second electromagnetic directional control valve EW6, keeping the second cartridge valve LC2 in a compressed state, blocking the hydraulic oil from flowing from the third oil port K through the fifth oil port to the fourth oil port B and blocking the hydraulic oil from flowing from the fourth oil port B through the fifth oil port to the third oil port K. When the boom descends, the hydraulic oil pushes the second cartridge valve LC2 to open from the third oil port K through the fifth oil port, and flows to the fourth oil port B through the second cartridge valve LC2. At this time, the second electromagnetic directional control valve EW6 is in the left working position (energized position), and the spring chamber of the second cartridge valve LC2 is connected to the fourth oil port B through the second electromagnetic directional control valve EW6, blocking the hydraulic oil from flowing from the fourth oil port B through the fifth oil port to the third oil port K.

[0042] Before adding the shuttle valve, the second cartridge valve LC2 is in the left working position (non-energized position), where it can only block the flow from the fourth port B to the fifth port and cannot block the flow from the fifth port to the fourth port B. When the second solenoid valve, acting as an electromagnetic pilot valve, is energized, it controls the hydraulic oil to enter the second cartridge valve LC2, pushing the cone valve to move, and putting the second cartridge valve LC2 in the "open" state. When the second solenoid valve, acting as an electromagnetic pilot valve, is de-energized, the pressure in the spring chamber of the second cartridge valve LC2 is released, and the cone valve returns under the action of the spring force or system pressure, putting the second cartridge valve LC2 in the "closed" state. Without the shuttle valve, the second cartridge valve LC2 can only block the unidirectional flow. To achieve bidirectional blocking, a shuttle valve is added to the auxiliary oil circuit in the embodiment of the present application. The shuttle valve functions like two one-way valves. The shuttle valve selects the end with the higher pressure between the fifth port and the fourth port B and introduces its pressure into the spring chamber of the second cartridge valve LC2. In this way, no matter whether there is a higher pressure at the fifth port or the fourth port B, it can act on the spring chamber of the second cartridge valve LC2 through the shuttle valve, keeping the cone valve in a pressed state, thus achieving bidirectional blocking. In this case, the second solenoid valve directly controls the pressure in the spring chamber of the second cartridge valve LC2 to achieve the bidirectional blocking function of the second cartridge valve LC2.

[0043] The energy-saving device in the embodiment of the present application has three working positions: the boom raising position, the boom lowering position, and the middle position.

[0044] Working in the boom raising position: Receiving the boom raising signal, the first electromagnetic directional valve EW5 is energized. The spring chamber of the first cartridge valve LC1 is connected to the first port A through the first electromagnetic directional valve EW5, blocking the hydraulic oil from flowing from the first port A through the second port to the third port K. The spring chamber of the second cartridge valve LC2 is connected to the shuttle valve, blocking the hydraulic oil from flowing from the third port K through the fifth port to the fourth port B and from the fourth port B through the fifth port to the third port K.

[0045] Working in the boom lowering position: Receiving the boom lowering signal, the second electromagnetic directional valve EW6 is energized. The spring chamber of the second cartridge valve LC2 is connected to the fourth port B, blocking the hydraulic oil from flowing from the fourth port B through the fifth port to the third port K. The spring chamber of the first cartridge valve LC1 is connected to the second port, blocking the hydraulic oil from flowing back from the third port K through the second port to the first port A. The hydraulic oil flows in from the first port A, pushing the first cartridge valve LC1 to open, connecting the spring chamber of the first cartridge valve LC1, and keeping the oil flow rate stable. The hydraulic oil passes through the second port and flows to the second cartridge valve LC2. After pushing the second cartridge valve LC2 to open, it connects the spring chamber of the second cartridge valve LC2 and keeps the oil flow rate stable. The hydraulic oil flows into the rod chamber of the boom cylinder through the fourth port B. Part of the excess hydraulic oil flows into the accumulator through the third port K to achieve the purpose of energy saving. If the working pressure of the valve body is greater than the safety value, the relief valve Re opens, and the flow rate in the valve body flows through the relief valve Re to the fuel tank, making the working pressure not greater than the safety pressure.

[0046] Boom middle position operation: No signal is received, both solenoid directional control valves are not energized. The first cartridge valve LC1 blocks the hydraulic oil from flowing from the second oil port to the first oil port A, and the second cartridge valve LC2 blocks the hydraulic oil from flowing in both directions between the fifth oil port and the fourth oil port B. The oil in the rod chamber of the boom cylinder is locked, and the boom is locked.

[0047] The above description of the embodiments of the present application is only part of the embodiments of the present application, which is used to enable those skilled in the art to implement or use the content of the present application, and is not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An energy-saving device applicable to a hydraulic excavator, characterized in that, Including: A shuttle valve, a first electromagnetic directional valve, a second electromagnetic directional valve, a first cartridge valve and a second cartridge valve; The first cartridge valve is provided with a first oil port and a second oil port; the second cartridge valve is provided with a fourth oil port and a fifth oil port; The working positions of the first electromagnetic directional valve and the second electromagnetic directional valve both include a left working position and a right working position; the first electromagnetic directional valve and the second electromagnetic directional valve switch working positions according to the boom movement signal of the hydraulic excavator; The first electromagnetic directional valve switches to the left working position in response to a boom rising signal; when the first electromagnetic directional valve is in the left working position, the spring chamber of the first cartridge valve is communicated with the first oil port through the first electromagnetic directional valve; when the first electromagnetic directional valve is in the right working position, the spring chamber of the first cartridge valve is communicated with the second oil port through the first electromagnetic directional valve; the second oil port is communicated with the third oil port; The second electromagnetic directional valve switches to the left working position in response to a boom lowering signal; when the second electromagnetic directional valve is in the left working position, the spring chamber of the second cartridge valve is communicated with the fourth oil port through the second electromagnetic directional valve; when the second electromagnetic directional valve is in the right working position, the spring chamber of the second cartridge valve is communicated with the outlet of the shuttle valve through the second electromagnetic directional valve; the two inlets of the shuttle valve are respectively connected to the fourth oil port and the fifth oil port; the fifth oil port is communicated with the third oil port; The first oil port is connected to the rodless chamber of the boom cylinder of the hydraulic excavator, the fourth oil port is connected to the rod chamber of the boom cylinder of the hydraulic excavator, and the third oil port is connected to the accumulator.

2. The energy-saving device according to claim 1, wherein The second oil port and the fifth oil port are connected.

3. The energy-saving device according to claim 2, wherein, It further includes a plate-type ball valve, the inlet of the plate-type ball valve is communicated with the third oil port, the second oil port and the fifth oil port, and the outlet of the plate-type ball valve is communicated with the fuel tank.

4. The energy-saving device according to claim 2, characterized in that, It further includes a relief valve, the inlet of the relief valve is communicated with the third oil port, the second oil port and the fifth oil port, and the outlet of the relief valve is communicated with the fuel tank.

5. The energy-saving device according to any one of claims 2 to 4, characterized in that, It further includes a first pressure detector, which is installed in the pipeline where the second oil port and the fifth oil port are communicated.

6. The energy-saving device according to any one of claims 1 to 4, characterized in that, It further includes a second pressure detector and a third pressure detector, which are respectively installed in the rodless chamber and the rod chamber of the boom cylinder.

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