An energy-saving device for recovering the potential energy of the boom of an excavator based on shunt and supercharging technologies

Abstract

The invention discloses an energy-saving device for recovering the potential energy of a boom of an excavator, which comprises a boom hydraulic cylinder, a hydraulic system and an energy-saving device valve block. The hydraulic system includes a pilot control valve, a variable pump and a proportional reversing valve. The pilot control valve is connected to the proportional reversing valve. The proportional reversing valve is connected to a fuel tank through the variable pump. The working oil port d of the proportional reversing valve is connected to the piston chamber of the boom hydraulic cylinder. The energy-saving device valve block includes a pre-shunt reversing valve. The piston chamber of the boom hydraulic cylinder is connected to the working oil port c of the pre-shunt reversing valve. The working oil port b of the pre-shunt reversing valve is connected to the working oil port e of the proportional reversing valve. The energy-saving device can realize flow regeneration during the descending process of the boom of the excavator, reduce the oil supply of the variable pump, and when the excavator has other operations, boost half of the hydraulic energy converted from the potential energy and merge it with the pump outlet for reuse, thereby reducing the fuel consumption of the engine and achieving the purpose of energy conservation, emission reduction and environmental protection.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic construction machinery, and particularly to an energy-saving device for recovering the potential energy of the boom of an excavator based on flow splitting and boosting technologies. Background Art

[0002] With the implementation of policies such as large-scale infrastructure construction and urbanization construction in the country, the construction machinery industry has achieved rapid development. As one of the construction machinery, hydraulic excavators have been widely used in many fields such as industrial production, transportation, mining, and infrastructure construction.

[0003] Traditional hydraulic excavators have problems of high energy consumption and low energy utilization rate. Only 20% of the output power of the engine is converted into the effective power of the excavator. When the excavator performs lifting and lowering operations, the boom is frequently lifted and lowered. Due to the large mass of the working device, a large amount of potential energy is released during the lowering process. Most of this energy is consumed at the throttle orifice of the hydraulic valve and converted into heat energy, resulting in energy waste and oil heating, which affects the stability of the entire system.

[0004] Among the recoverable energies of an excavator, the recoverable energy of the boom cylinder accounts for a large proportion. Therefore, the research on the recovery and reuse of the potential energy of the boom during the lowering of the excavator is an important step in improving the energy utilization rate of the excavator. At the same time, it can also play a role in energy conservation, emission reduction, and environmental protection.

[0005] During the frequent lifting and lowering of the boom of a hydraulic excavator, if no energy-saving device is installed, the potential energy of the boom will be dissipated in the throttle valve orifice in the form of heat energy, causing huge energy waste and leading to an increase in oil temperature. It is necessary to add a high-power radiator additionally, increasing the installation cost of the excavator.

[0006] With the development of energy-saving technologies, certain progress has been made in the potential energy recovery technology of the boom of hydraulic excavators. For the recovery of the potential energy of the boom of an excavator, most of the current research on the potential energy recovery during the lowering of the boom focuses on two aspects: hydraulic and electrical energy recovery. The electrical energy recovery system has complex equipment, and the costs of electrical energy storage components and generators are relatively high, which restricts the application of this recovery solution in practice. Moreover, during the energy recovery process, there are many conversion links, and the energy recovery utilization rate is restricted. The hydraulic energy recovery system stores the potential energy of the lowering boom in the hydraulic accumulator in the form of hydraulic energy. However, the existing hydraulic accumulators have the problem of insufficient energy storage density, resulting in a relatively large volume, requiring a large installation space, and too high cost, which to a certain extent restricts their practical application. Summary of the Invention

[0007] The purpose of the present invention is to provide an energy-saving device for recovering the potential energy of the boom of an excavator based on flow splitting and boosting technologies to solve the problems in the prior art.

[0008] To achieve the above object, the present invention provides a boom potential energy recovery and energy-saving device for an excavator based on flow splitting and boosting technologies, including a boom hydraulic cylinder and a hydraulic system.

[0009] The hydraulic system includes a pilot control valve, a variable pump, a cooling motor, an auxiliary pump check valve, a cooler, a proportional direction valve, an upper chamber overload oil replenishing valve and a lower chamber overload oil replenishing valve, a boom locking valve and a hydraulic control direction valve.

[0010] The pilot control valve includes a rising pilot control valve and a falling pilot control valve. The outlet xBmA of the rising pilot control valve is connected to the right control end of the proportional direction valve, and the outlet xBmB of the falling pilot control valve is connected to the left control end of the proportional direction valve and the control end of the hydraulic control direction valve.

[0011] The pilot control valve is connected to the cooler through the auxiliary pump check valve and the cooling motor.

[0012] The auxiliary pump check valve is connected to the fuel tank through an auxiliary pump.

[0013] The cooler is connected to the proportional direction valve.

[0014] The proportional direction valve is connected to the fuel tank through the variable pump.

[0015] The working oil port d of the proportional direction valve is connected to the boom locking valve through the upper chamber overload oil replenishing valve and the lower chamber overload oil replenishing valve.

[0016] The boom locking valve is connected to the hydraulic control direction valve.

[0017] The working oil port d of the proportional direction valve is connected to the piston chamber of the boom hydraulic cylinder.

[0018] For a boom potential energy recovery and direct utilization energy-saving device for an excavator based on flow splitting and boosting technologies, it further includes an energy-saving device valve block.

[0019] The energy-saving device valve block includes a pre-splitting direction valve.

[0020] The piston chamber of the boom hydraulic cylinder is connected to the working oil port c of the pre-splitting direction valve.

[0021] The working oil port b of the pre-splitting direction valve is connected to the working oil port e of the proportional direction valve. When the boom of the excavator descends, the oil in the lower chamber of the boom hydraulic cylinder flows through the flow splitting valve. Half of the flow rate flows to the upper chamber of the oil cylinder to achieve flow regeneration, and the other half is directly reused when the excavator has other operations.

[0022] Furthermore, the energy-saving device valve block further includes a flow splitting valve and a post-splitting direction valve.

[0023] The working oil port a of the pre-shunt reversing valve is connected to the working oil port e of the proportional reversing valve through the working oil port b of the shunt valve, and the working oil port a of the shunt valve is connected to the variable pump.

[0024] Furthermore, the energy-saving device valve block further includes a post-shunt reversing valve and a booster. The working oil port a of the shunt valve is connected to the working oil port c of the post-shunt reversing valve. The working oil port b of the post-shunt reversing valve is connected to the variable pump through the booster, and the oil return port of the booster is connected to the fuel tank.

[0025] Furthermore, the working oil port a of the post-shunt reversing valve is connected to the cooling motor. When there is no other action after the boom of the excavator descends, the other half of the flow rate of the oil in the lower chamber of the boom hydraulic cylinder drives the cooling motor after passing through the shunt valve to dissipate heat from the cooler.

[0026] Furthermore, the hydraulic system further includes a boom locking valve.

[0027] The energy-saving device valve block further includes a hydraulically controlled switching valve.

[0028] The working oil port b of the shunt valve is connected to the working oil port e of the proportional reversing valve through the hydraulically controlled switching valve and the boom locking valve.

[0029] Furthermore, the outlet xBmB of the hydraulically controlled switching valve is connected to the left control end of the proportional reversing valve.

[0030] Furthermore, the control end xC of the post-shunt reversing valve is connected to the control end of the variable pump.

[0031] Furthermore, the control end xBmB of the pre-shunt reversing valve is connected to the right control end of the proportional reversing valve.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. When the boom of the excavator in the present invention descends, the oil in the lower chamber of the boom cylinder passes through the shunt valve. Half of the flow rate goes to the upper chamber of the cylinder, realizing flow regeneration, reducing the oil supply of the variable pump, and reducing the fuel consumption of the engine. When the excavator has other actions, the other half of the flow rate can be directly reused to achieve energy conservation and emission reduction; when the excavator has no other actions, the other half of the flow rate is used to drive the cooling fan to rotate, improving the heat dissipation capacity of the excavator.

[0034] 2. The direct utilization scheme of the boom potential energy recovery of the excavator based on shunt and boost adopted in the present invention, compared with the existing direct utilization device for boom potential energy recovery of the excavator, consists of only a few hydraulic components, does not require an accumulator and an electronic control system, has a low cost and high reliability. This scheme reduces the oil supply of the hydraulic pump to a certain extent, reduces the fuel consumption of the engine, effectively improves the efficiency of the hydraulic system, and achieves the purpose of energy conservation and emission reduction. Description of the Drawings

[0035] Figure 1 This is a connection diagram of an energy-saving device for recovering the potential energy of the boom of an excavator based on the shunt and supercharging technologies according to the present invention.

[0036] In the figure: 1. Boom hydraulic cylinder; 10. Variable pump; 11. Main pump check valve; 12. Proportional directional valve; 13. Overload oil replenishing valve for the upper chamber; 14. Overload oil replenishing valve for the lower chamber; 15. Boom locking valve; 16. Hydraulically controlled directional valve; 17. Auxiliary pump; 18. Rising pilot control valve; 19. Lowering pilot control valve; 20. Cooler; 21. Cooling motor; 22. Auxiliary pump check valve; 30. Pre-shunt directional valve; 31. Hydraulically controlled switching valve; 32. Shunt valve; 33. Post-shunt directional valve; 34. Supercharger. Detailed Embodiments

[0037] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. For those not specified in the embodiments, they shall be carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0038] Embodiment 1: As Figure 1 shown, an energy-saving device for recovering the potential energy of the boom of an excavator based on the shunt and supercharging technologies includes a boom hydraulic cylinder 1 and a hydraulic system.

[0039] The hydraulic system includes a pilot control valve, a variable pump 10, a cooling motor 21, an auxiliary pump check valve 22, a cooler 20, a proportional directional valve 12, an overload oil replenishing valve 13 for the upper chamber, an overload oil replenishing valve 14 for the lower chamber, a boom locking valve 15, and a hydraulically controlled directional valve 16.

[0040] The pilot control valve includes a rising pilot control valve 18 and a lowering pilot control valve 19. The outlet xBmA of the rising pilot control valve 18 is connected to the right control end of the proportional directional valve 12. The outlet xBmB of the lowering pilot control valve 19 is connected to the left control end of the proportional directional valve 12 and the control end of the hydraulically controlled directional valve 16.

[0041] The pilot control valve is connected to the cooler 20 through the auxiliary pump check valve 22 and the cooling motor 21.

[0042] The auxiliary pump check valve 22 is connected to the fuel tank through the auxiliary pump 17.

[0043] The cooler 20 is connected to the proportional directional valve 12.

[0044] The proportional directional valve 12 is connected to the fuel tank through the variable pump 10.

[0045] The working oil port d of the proportional directional valve 12 is connected to the boom locking valve 15 through the upper chamber overload oil replenishing valve 13 and the lower chamber overload oil replenishing valve 14.

[0046] The boom locking valve 15 is connected to the hydraulic control directional valve 16.

[0047] The working oil port d of the proportional directional valve 12 is connected to the piston chamber of the boom cylinder 1.

[0048] It is an energy-saving device for directly utilizing the recovered potential energy of the boom of an excavator based on flow splitting and boosting technologies, and also includes an energy-saving device valve block.

[0049] The energy-saving device valve block includes a pre-splitting directional valve 30.

[0050] The piston chamber of the boom cylinder 1 is connected to the working oil port c of the pre-splitting directional valve 30.

[0051] The working oil port b of the pre-splitting directional valve 30 is connected to the working oil port e of the proportional directional valve 12.

[0052] When the excavator is working, driven by the pilot control valve, the oil discharged from the variable pump 10 enters the piston chamber of the boom cylinder through the working oil port d of the proportional directional valve 12. The oil in the piston chamber of the boom cylinder 1 enters the flow splitting valve 32. Half of the oil discharged from the working oil port b of the flow splitting valve 32 enters the working oil port e of the proportional directional valve 12 and merges with the oil from the working oil port d of the proportional directional valve 12, and then is supplied to the piston chamber of the boom cylinder 1 again to achieve flow regeneration.

[0053] The energy-saving device valve block also includes a flow splitting valve 32 and a post-splitting directional valve 33.

[0054] The working oil port a of the pre-splitting directional valve 30 is connected to the working oil port e of the proportional directional valve 12 through the working oil port b of the flow splitting valve 32.

[0055] The working oil port a of the flow splitting valve 32 is connected to the variable pump 10.

[0056] The energy-saving device valve block also includes a post-splitting directional valve 33 and a booster 34. The working oil port a of the flow splitting valve 32 is connected to the working oil port c of the post-splitting directional valve 33. The working oil port b of the post-splitting directional valve 33 is connected to the variable pump 10 through the booster 34, and the oil return port of the booster 34 is connected to the fuel tank.

[0057] After the boom of the excavator descends, if the excavator has other operations, the other half of the oil discharged from the working oil port a of the flow splitting valve 32 is output to the booster 34 through the working oil port b of the post-splitting directional valve 33. The oil boosted by the booster 34 merges with the oil discharged from the variable pump 10 and then enters the proportional directional valve 12 to supply the excavator to work, and the oil supply of the variable pump 10 is further reduced.

[0058] The working oil port a of the post-shunt reversing valve 33 is connected to the cooling motor 21.

[0059] When there is no other movement of the excavator, the pressure output by the variable pump 10 is low. The oil flowing from the lower chamber of the boom cylinder 1 through the shunt valve 32 into the post-shunt reversing valve 33 does not change direction. After the oil output from the working oil port a of the shunt valve 32 passes through the working oil port a of the post-shunt reversing valve 33, it merges with the oil output by the auxiliary pump 17 and enters the cooling motor 21. The cooling motor 21 drives the fan to rotate to dissipate heat from the cooler 20.

[0060] The hydraulic system further includes a boom locking valve 15.

[0061] The energy-saving device valve block further includes a hydraulically controlled switching valve 31.

[0062] The working oil port b of the shunt valve 32 is connected to the working oil port e of the proportional reversing valve 12 through the hydraulically controlled switching valve 31 and the boom locking valve 15.

[0063] The outlet xBmB of the hydraulically controlled switching valve 31 is connected to the left control end of the proportional reversing valve 12.

[0064] The control end xC of the post-shunt reversing valve 33 is connected to the control end of the variable pump 10.

[0065] The control end xBmB of the pre-shunt reversing valve 30 is connected to the right control end of the proportional reversing valve 12.

[0066] The working principle of the present invention is as follows:

[0067] When the driver operates the excavator handle and presses down the lowering pilot control valve 19, the control signal xBmB causes the pre-shunt reversing valve 30 and the hydraulically controlled switching valve 31 to change direction. The control signal xBmB also causes the hydraulically controlled reversing valve 16 to change direction. The control chamber of the boom locking valve 15 is connected to the fuel tank, and the boom locking valve 15 opens reversely. At the same time, the control signal xBmB causes the proportional reversing valve 12 to work in the left position. The oil output by the variable pump 10 passes through the main pump check valve 11 and the proportional reversing valve 12 and is output from the d port of the proportional reversing valve 12 and enters the piston chamber of the boom cylinder 1. The oil in the piston chamber of the boom cylinder 1 passes through the pre-shunt reversing valve 30 and is output from the a port and enters the shunt valve 32. Half of the oil output from the b port of the shunt valve 32 enters the proportional reversing valve 12 through the boom locking valve 15 and merges with the oil entering from the d port to supply the piston chamber of the boom cylinder 1 to achieve flow regeneration. The oil supply of the variable pump 10 is reduced, and the engine fuel volume is also reduced.

[0068] If the excavator has other operations at this time, the variable pump 10 outputs high pressure. When the control signal xC is higher than the set value of the spring of the post-shunt directional valve 33, the post-shunt directional valve 33 changes its direction. The other half of the oil output from port a of the flow dividing valve 32 passes through the post-shunt directional valve 33 and is output from port b and enters the supercharger 34. The oil after being supercharged by the supercharger 34 merges with the oil output by the variable pump 10 and enters the inlet of the proportional directional valve 12 for the excavator to work. The oil supply of the variable pump 10 is further reduced, and the engine fuel quantity is also further reduced, converting the potential energy of the boom lowering into hydraulic energy to achieve the purpose of energy conservation and emission reduction.

[0069] If the excavator has no other operations at this time, the pressure output by the variable pump 10 is low. The control signal xC is lower than the set value of the spring of the post-shunt directional valve 33, and the post-shunt directional valve 33 does not change its direction. The oil output from port a of the flow dividing valve 32 passes through the post-shunt directional valve 33 and is output from port a and merges with the oil output by the auxiliary pump 17 and enters the cooling motor 21. The cooling motor 21 drives the fan to rotate to discharge air and let the cooler 20 dissipate heat, thus improving the heat dissipation capacity of the excavator.

[0070] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit and basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0071] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An energy-saving device for recovering the potential energy of the boom of an excavator based on shunt and boost technologies, comprising a boom hydraulic cylinder (1) and a hydraulic system. The hydraulic system includes a pilot control valve, a variable pump (10), a cooling motor (21), an auxiliary pump check valve (22), a cooler (20), a proportional directional valve (12), an upper chamber overload oil compensating valve (13) and a lower chamber overload oil compensating valve (14), a boom locking valve (15) and a hydraulic control directional valve (16). The pilot control valve includes a rising pilot control valve (18) and a falling pilot control valve (19). The outlet xBmA of the rising pilot control valve (18) is connected to the right control end of the proportional directional valve (12), and the outlet xBmB of the falling pilot control valve (19) is connected to the left control end of the proportional directional valve (12) and the control end of the hydraulic control directional valve (16). The pilot control valve is connected to the cooler (20) through the auxiliary pump check valve (22) and the cooling motor (21). The auxiliary pump check valve (22) is connected to the fuel tank through an auxiliary pump (17). The cooler (20) is connected to the proportional directional valve (12). The proportional directional valve (12) is connected to the fuel tank through the variable pump (10). The working oil port d of the proportional directional valve (12) is connected to the boom locking valve (15) through the upper chamber overload oil compensating valve (13) and the lower chamber overload oil compensating valve (14). The boom locking valve (15) is connected to the hydraulic control directional valve (16). The working oil port d of the proportional directional valve (12) is connected to the piston chamber of the boom hydraulic cylinder (1). It is characterized in that It also includes an energy-saving device valve block. The energy-saving device valve block includes a pre-shunt reversing valve (30). The piston chamber of the boom hydraulic cylinder (1) is connected to the working oil port c of the pre-shunt reversing valve (30). The working oil port b of the pre-shunt reversing valve (30) is connected to the working oil port e of the proportional reversing valve (12). The energy-saving device valve block further includes a shunt valve (32) and a post-shunt reversing valve (33). The working oil port a of the pre-shunt reversing valve (30) is connected to the working oil port e of the proportional reversing valve (12) through the working oil port b of the shunt valve (32), and the working oil port a of the shunt valve (32) is connected to the variable pump (10). The energy-saving device valve block further includes a post-shunt reversing valve (33) and a booster (34). The working oil port a of the shunt valve (32) is connected to the working oil port c of the post-shunt reversing valve (33). The working oil port b of the post-shunt reversing valve (33) is connected to the variable pump (10) through the booster (34), and the oil return port of the booster (34) is connected to the fuel tank.

2. The energy-saving device for recovering the potential energy of the boom of an excavator based on shunt and boost technologies according to claim 1, characterized in that The working oil port a of the post-shunt reversing valve (33) is connected to the cooling motor (21).

3. The energy-saving device for recovering the potential energy of the boom of an excavator based on shunt and boost technologies according to claim 1, characterized in that The hydraulic system further includes a boom locking valve (15). The energy-saving device valve block further includes a hydraulically controlled switching valve (31). The working oil port b of the shunt valve (32) is connected to the working oil port e of the proportional reversing valve (12) through the hydraulically controlled switching valve (31) and the boom locking valve (15).

4. The energy-saving device for recovering the potential energy of the boom of an excavator based on the flow splitting and supercharging technology according to claim 3, wherein, The outlet xBmB of the hydraulically controlled switching valve (31) is connected to the left control end of the proportional reversing valve (12).

5. The energy-saving device for recovering the potential energy of the boom of an excavator based on the flow splitting and supercharging technology according to claim 2, wherein, The control end xC of the post-shunt reversing valve (33) is connected to the control end of the variable pump (10).

6. The energy-saving device for recovering the potential energy of the boom of an excavator based on the flow splitting and supercharging technology according to claim 1, wherein, The control end xBmB of the pre-shunt reversing valve (30) is connected to the right control end of the proportional reversing valve (12).

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