A system for improving the dynamic response characteristics of excavators

Abstract

The embodiment of the present application provides a system for improving the dynamic response characteristics of an excavator, and the system for improving the dynamic response characteristics of an excavator includes: a hydraulic device, which is used to connect to an engine and generate hydraulic oil with a target pressure under the drive of the engine; a recovery device, which is connected to the hydraulic device and used to recover the hydraulic oil; a liquid-driven turbine, which is connected to the recovery device and connected to the hydraulic device through a transmission component; and a control device, which is respectively connected to the hydraulic device, the recovery device and the transmission component. The present application realizes efficient recovery and utilization of hydraulic oil energy and improves the dynamic response characteristics of the excavator.

Description

Technical Field

[0001] The present application relates to the technical field of engineering machinery, and in particular to a system for improving the dynamic response characteristics of an excavator. Background Art

[0002] Hydraulic excavator is a multifunctional machine, which is widely used in mechanical construction such as water conservancy projects, transportation, power projects and mining. It plays a very important role in reducing heavy physical labor, ensuring project quality, speeding up construction and improving labor productivity. During the operation of the excavator, in order to effectively improve the operating efficiency of the excavator, it is necessary to ensure that the excavator has good power response characteristics. In the prior art, the method of pre-increasing the speed or output power of the diesel engine is usually adopted to improve the engine power response characteristics during the loading process, but the turbocharger on the diesel engine itself has an inherent "turbo lag" phenomenon, which will cause the diesel engine cylinder intake volume to increase slowly. Therefore, this type of method has a very limited effect on improving the power response characteristics, and will also increase unnecessary energy consumption. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a system for improving the dynamic response characteristics of an excavator, so as to achieve efficient recovery and utilization of hydraulic oil energy and improve the dynamic response characteristics of the excavator.

[0004] A first aspect of an embodiment of the present application provides a system for improving the dynamic response characteristics of an excavator, comprising: a hydraulic device, connected to an engine, and driven by the engine to generate hydraulic oil with a target pressure; a recovery device, connected to the hydraulic device and used to recover the hydraulic oil; a liquid-driven turbine, connected to the recovery device and connected to the hydraulic device via a transmission assembly; and a control device, respectively connected to the hydraulic device, the recovery device and the transmission assembly.

[0005] In one embodiment, the hydraulic device includes: a hydraulic pump, the liquid-driven turbine is connected to the hydraulic pump through the transmission assembly; a hydraulic valve group, connected to the hydraulic pump through a first hydraulic pipeline, and connected to the recovery device.

[0006] In one embodiment, the recovery device includes: a control valve group connected to the hydraulic device through a second hydraulic pipeline and connected to the liquid-driven turbine; and an energy storage unit connected to the control valve group and used to store the recovered hydraulic oil.

[0007] In one embodiment, the transmission assembly includes: a reduction mechanism, and the reduction mechanism is transmission-connected to the liquid-driven turbine.

[0008] In one embodiment, the speed reduction mechanism includes: a first gear disposed on a turbine shaft of the hydraulic turbine; a second gear disposed on a connecting shaft between the hydraulic device and the engine, and the second gear meshes with the first gear.

[0009] In one embodiment, the transmission assembly further includes: a sliding clutch, which is disposed between the reduction mechanism and the turbine shaft of the liquid-driven turbine and is connected to the control device.

[0010] In one embodiment, a diameter of the second gear is greater than a diameter of the first gear.

[0011] In one embodiment, the excavator dynamic response characteristic improvement system further includes: an oil-using device connected to the hydraulic device via a third hydraulic pipeline.

[0012] In one embodiment, the oil-using device includes a swing motor, a boom cylinder, an arm cylinder and a bucket cylinder, and the swing motor, the boom cylinder, the arm cylinder and the bucket cylinder are respectively connected to the hydraulic device.

[0013] In one embodiment, the excavator power response characteristic improvement system further includes: an engine connected to the hydraulic device and the control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a structural schematic diagram of a system for improving the dynamic response characteristics of an excavator according to an embodiment of the present application.

[0016] Reference numerals:

[0017] 100-excavator power response characteristic improvement system, 110-engine, 120-hydraulic device, 121-hydraulic pump, 122-hydraulic valve group, 123-first hydraulic pipeline, 124-connecting shaft, 130-recovery device, 131-second hydraulic pipeline, 132-control valve group, 133-energy storage unit, 140-liquid-driven turbine, 141-turbine shaft, 150-transmission assembly, 151-first gear, 152-second gear, 153-sliding clutch, 154-reduction mechanism, 160-control device, 170-oil device, 171-slewing motor, 172-boom cylinder, 173-arm cylinder, 174-bucket cylinder, 175-third hydraulic pipeline, 180-operating handle. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0019] In the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and do not indicate the order of arrangement, nor can they be understood as indicating or implying relative importance.

[0020] In the description of this application, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0021] In the description of the present application, the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0022] In the description of this application, unless otherwise clearly specified and limited, the terms "installed", "set", "provided with", "connected", and "configured to" should be understood in a broad sense. For example, it 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 connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] Please see Figure 1 , which is a structural schematic diagram of an excavator dynamic response characteristic improvement system 100 according to an embodiment of the present application, comprising: an engine 110, a hydraulic device 120, a recovery device 130, a liquid-driven turbine 140, a control device 160 and an oil-using device 170, wherein the hydraulic device 120 is connected to the engine 110, and the hydraulic device 120 generates hydraulic oil with a target pressure driven by the engine 110, the recovery device 130 is connected to the hydraulic device 120 for recovering the hydraulic oil, the liquid-driven turbine 140 is connected to the recovery device 130, and is connected to the hydraulic device 120 through a transmission assembly 150, the control device 160 is respectively connected to the hydraulic device 120, the recovery device 130, the transmission assembly 150 and the engine 110, and the oil-using device 170 is connected to the hydraulic device 120 through a third hydraulic pipeline 175.

[0024] In one embodiment, the hydraulic device 120 includes a hydraulic pump 121 and a hydraulic valve group 122. The engine 110 is connected to the hydraulic pump 121 through a connecting shaft 124. The hydraulic turbine 140 is connected to the hydraulic pump 121 through a transmission assembly 150. The hydraulic valve group 122 is connected to the hydraulic pump 121 through a first hydraulic pipeline 123, and is connected to the recovery device 130 through a second hydraulic pipeline 131, and is connected to the oil-using device 170 through a third hydraulic pipeline 175. The engine 110 drives the hydraulic pump 121 to operate at a target gear speed, continuously generates hydraulic oil with a certain pressure, and flows to the hydraulic valve group 122 through the first hydraulic pipeline 123. The excavator driver can operate the excavator through the operating handle 180. The movement of the operating handle 180 will generate an electrical signal. The control device 160 controls the opening or closing of each hydraulic valve in the hydraulic valve group 122 according to the electrical signal or the pressure signal of the pilot hydraulic pipeline, so that the hydraulic oil can flow to the oil-using device 170 and / or the recovery device 130 according to the operation needs. In one embodiment, the control device 160 can determine the action requirements and load requirements that the excavator is about to perform based on the position sensor information of the operating handle 180 or the pilot hydraulic line pressure information, and generate a control signal to adjust the swash plate angle of the hydraulic pump 121, thereby adjusting the hydraulic oil flow.

[0025] In one embodiment, the recovery device 130 includes a control valve group 132 and an energy storage unit 133. The control valve group 132 is connected to the hydraulic device 120 through the second hydraulic pipeline 131 and is connected to the liquid-driven turbine 140. The energy storage unit 133 is connected to the control valve group 132 for storing the recovered hydraulic oil. In one embodiment, the control valve group 132 recovers the hydraulic oil with appropriate pressure into the energy storage unit 133 according to the control signal of the control device 160. When power assistance is required, the control device 160 controls the control valve group 132 to deliver the hydraulic oil with pressure in the energy storage unit 133 to the liquid-driven turbine 140, driving the liquid-driven turbine 140 to rotate, thereby converting the hydraulic energy of the hydraulic oil into rotational kinetic energy, and directly driving the hydraulic pump 121 through the transmission assembly 150.

[0026] In one embodiment, the oil device 170 includes a swing motor 171 , a boom cylinder 172 , an arm cylinder 173 and a bucket cylinder 174 , and the swing motor 171 , the boom cylinder 172 , the arm cylinder 173 and the bucket cylinder 174 are respectively connected to the hydraulic valve group 122 of the hydraulic device 120 . In one embodiment, hydraulic oil of a certain pressure continuously flows from the hydraulic pump 121 to the hydraulic valve group 122 through the first hydraulic pipeline 123, and flows into the swing motor 171, the boom cylinder 172, the arm cylinder 173 and the bucket cylinder 174 through different channels of the third hydraulic pipeline 175. At the same time, hydraulic oil in the swing motor 171, the boom cylinder 172, the arm cylinder 173 and the bucket cylinder 174 also flows back to the hydraulic valve group 122, and then enters the control valve group 132. The control valve group 132 recovers the hydraulic oil with appropriate pressure into the energy storage unit 133 according to the control signal of the control device 160.

[0027] In one embodiment, for a hydraulic excavator with a boom potential energy recovery function, the hydraulic oil flowing out of the boom cylinder 172 flows into the arm cylinder 173 and / or the bucket cylinder 174, resulting in a reduction in the recoverable hydraulic oil energy at the boom cylinder 172. In order not to affect the effect of improving the dynamic response characteristics, in addition to recovering the hydraulic oil flowing back from the swing motor 171, the arm cylinder 173 and the bucket cylinder 174, the control valve group 132 can also directly send the high-pressure hydraulic oil generated by the hydraulic pump 121 into the energy storage unit 133 through the second hydraulic pipeline 131.

[0028] In one embodiment, when the excavator is working with a small load, for example, the excavator is in a flat ground condition, the engine 110 is in a light load state, deviating from the optimal economic zone of the engine 110, and reducing the operating efficiency. The control device 160 can increase the hydraulic oil displacement of the hydraulic pump 121, thereby increasing the load of the engine 110, making it close to or enter the optimal economic zone, improving the operating efficiency of the engine 110, and saving fuel consumption, and the additional hydraulic oil displacement generated by the hydraulic pump 121 can be recovered to the energy storage unit 133 through the control valve group 132, and provided to the liquid-driven turbine 140 to drive the hydraulic pump 121 when the power response characteristics need to be improved later.

[0029] In one embodiment, the transmission assembly 150 includes a speed reduction mechanism 154 and a sliding clutch 153, wherein the speed reduction mechanism 154 includes a first gear 151 and a second gear 152, the first gear 151 is arranged on the turbine shaft 141 of the liquid-driven turbine 140, the second gear is arranged on the connecting shaft 124 of the hydraulic device 120 and the engine 110, the second gear 152 is meshed with the first gear 151, and the diameter of the second gear 152 is greater than the diameter of the first gear 151, so as to achieve the speed matching between the high-speed rotation of the liquid-driven turbine 140 and the low-speed rotation of the hydraulic pump 121 of the engine 110. The sliding clutch 153 is arranged between the first gear 151 and the turbine shaft 141 of the liquid-driven turbine 140, and is connected to the control device 160, and the control device 160 is used to control the separation and meshing state of the sliding clutch 153. In one embodiment, when the hydraulic turbine 140 is not needed to provide assistance, the control device 160 sends a signal to the control valve group 132 to reduce or shut down the hydraulic oil supplied to the hydraulic turbine 140. At the same time, the turbine shaft 141 is separated from the first gear 151 by the sliding clutch 153 to prevent the hydraulic turbine 140 from overspeeding or idling, thereby reducing its service life.

[0030] In one embodiment, the control device 160 transmits the hydraulic oil in the energy storage unit 133 to the liquid-driven turbine 140 through the control valve group 132 according to the need for the engine 110 to quickly provide power, drives the liquid-driven turbine 140 to rotate at a high speed, and converts the hydraulic energy into the kinetic energy of the turbine shaft 141. The first gear 151 installed on the turbine shaft 141 meshes with the second gear 152 installed on the connecting shaft 124 to operate, directly transmitting the kinetic energy of the turbine shaft 141 to the connecting shaft 124, and driving the hydraulic pump 121 to rotate. In one embodiment, the second gear 152 can also be installed on the flywheel of the engine 110. Since the liquid-driven turbine 140 directly transmits energy to the hydraulic pump 121, the power transmission is fast and the transmission efficiency is high, which can improve the matching degree between the output power of the hydraulic pump 121 and the external load demand, and significantly improve the power response characteristics of the excavator.

[0031] In one embodiment, when the external load suddenly increases, the engine 110 needs to quickly output power to the hydraulic pump 121. Due to the "turbo hysteresis" effect, the speed of the engine 110 drops significantly when the load suddenly increases. The control device 160 can obtain the external load sudden increase information in advance through the electrical signal of the operating handle 180 or the pilot hydraulic pipeline pressure signal, and control the valve group 132 to flow the hydraulic oil in the energy storage unit 133 to the liquid-driven turbine 140, drive the liquid-driven turbine 140 to rotate at a high speed, and generate rotational kinetic energy. The control device 160 also controls the sliding clutch 153 to engage, so that the rotational kinetic energy of the turbine shaft 141 is transmitted to the second gear 152 through the first gear 151, and the hydraulic pump 121 is quickly driven, which partially reduces or completely offsets the requirement for the output power of the engine 110, realizes the assistance to the engine 110, and meets the need for the sudden increase of the external load. In the process of providing assistance to the engine 110, the control device 160 can adjust the flow of hydraulic oil entering the liquid-driven turbine 140 instantaneously through the control valve group 132 according to the change of the external load, so as to adjust the magnitude of the assistance supplied to the engine 110. By directly driving the hydraulic pump 121 through the liquid-driven turbine 140, the speed drop of the engine 110 can be effectively reduced, so that the engine 110 can work stably and reduce fuel consumption.

[0032] In one embodiment, when the external load suddenly decreases, the power absorbed by the hydraulic pump 121 is instantly reduced. Due to the lag in the power output regulation of the engine 110, the speed of the engine 110 and the hydraulic pump 121 is instantly increased, far exceeding the speed set in the gear. The control device 160 can obtain the external load sudden drop information in advance, gradually reduce the swash plate angle of the hydraulic pump 121 to reduce the hydraulic oil displacement of the hydraulic pump 121, and at the same time, by timely controlling the hydraulic valve group 122, the hydraulic oil originally supplied to the rotary motor 171, the boom cylinder 172, the arm cylinder 173 and the bucket cylinder 174 is transferred to the energy storage unit 133 through the control valve group 132 to store the hydraulic energy, so that the output power of the hydraulic pump 121 changes from sudden drop to slow drop, thereby adapting to the characteristics of the slow power output regulation process of the engine 110, reducing the speed increase, and helping to reduce the noise of the engine 110 and the hydraulic pump 121, and reducing the increase in fuel consumption due to overspeed.

[0033] In one embodiment, the hydraulic oil pressure value inside the energy storage unit 133 can be set to three gears in order of size. The A1 value represents the maximum working value of the energy storage unit 133. After reaching this value, high-pressure hydraulic oil recovery is no longer performed to protect the energy storage unit 133 from damage. The A2 value represents the minimum working value of the energy storage unit 133. If it is lower than this value, it means that the working state of the subsequent liquid-driven turbine 140 will be affected, thereby affecting the drive of the hydraulic pump 121. A1 and A2 can be set according to actual needs. If a higher dynamic response characteristic is required, A1 and A2 are set to be closer.

[0034] In one embodiment, when the internal pressure of the energy storage unit 133 is between A1 and A2, and the hydraulic pump 121 or the engine 110 is in its non-efficient operating range, the control device 160 adjusts the hydraulic pump 121 or the engine 110 to make its operating condition point close to the efficient area. Because the optimal economic zones for the operation of the hydraulic pump 121 and the engine 110 are both under their high-load conditions, when the operating conditions of the hydraulic pump 121 or the engine 110 are adjusted to operate in their efficient areas, the hydraulic oil displacement of the hydraulic pump 121 will also increase, and the hydraulic valve connected to the second hydraulic pipeline 131 inside the hydraulic valve group 122 will be opened to transport the additional high-pressure hydraulic oil to the energy storage unit 133 through the second hydraulic pipeline 131.

[0035] In one embodiment, when the internal pressure of the energy storage unit 133 is between A1 and A2, and the hydraulic pump 121 and the engine 110 are both operating in their respective high efficiency zones, the hydraulic oil pressure at the outlet of the oil-using device 170 is relatively high, and more hydraulic energy can be recovered. Therefore, only the hydraulic oil at the outlet of the oil-using device 170 is recovered, and the operating conditions of the hydraulic pump 121 or the engine 110 are no longer adjusted.

[0036] In one embodiment, when the internal pressure of the energy storage unit 133 is lower than A2, regardless of whether the hydraulic pump 121 or the engine 110 is in high efficiency, the control device 160 controls the hydraulic pump 121 to actively increase the displacement of high-pressure hydraulic oil, and supplies high-pressure hydraulic oil to the energy storage unit 133 through the second hydraulic pipeline 131 and the control valve group 132 to increase its internal hydraulic energy.

[0037] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A system for improving the dynamic response characteristics of an excavator, characterized in that: include: A hydraulic device, the hydraulic device comprising a hydraulic pump and a hydraulic valve group, the hydraulic valve group being connected to the hydraulic pump via a first hydraulic pipeline, the hydraulic device being used to connect to an engine, and generating hydraulic oil with a target pressure under the drive of the engine; A recovery device, the recovery device comprising a control valve group and an energy storage unit, the control valve group is connected to the hydraulic valve group via a second hydraulic pipeline, and the energy storage unit is connected to the control valve group and is used to store the recovered hydraulic oil; A hydraulically driven turbine connected to the control valve group and connected to the hydraulic pump via a transmission assembly; A control device, connected to the hydraulic device, the recovery device and the transmission assembly respectively; The oil-using device comprises a slewing motor, a boom cylinder, a dipper arm cylinder and a bucket cylinder. The slewing motor, the boom cylinder, the dipper arm cylinder and the bucket cylinder are respectively connected to the hydraulic valve group through a third hydraulic pipeline.

2. The excavator dynamic response characteristic improvement system according to claim 1, characterized in that: The transmission assembly comprises: A speed reduction mechanism is drivingly connected to the liquid-driven turbine.

3. The excavator dynamic response characteristic improvement system according to claim 2, characterized in that: The deceleration mechanism comprises: A first gear, disposed on a turbine shaft of the liquid-driven turbine; The second gear is arranged on the connecting shaft between the hydraulic device and the engine, and the second gear is meshed with the first gear.

4. The excavator dynamic response characteristic improvement system according to claim 2, characterized in that: The transmission assembly also includes: The slip clutch is arranged between the speed reduction mechanism and the turbine shaft of the liquid-driven turbine and is connected to the control device.

5. The excavator dynamic response characteristic improvement system according to claim 3, characterized in that: The diameter of the second gear is greater than the diameter of the first gear.

6. The excavator dynamic response characteristic improvement system according to claim 1, characterized in that: Also includes: An engine is connected to the hydraulic device and the control device.

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