DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See sections 10 & rule 13)
1. TITLE OF THE INVENTION
A FLOW CONTROL VALVE AND FLOW SUMMATION SYSTEMS IN HIGH END EXCAVATORS TO FACILITATE ON DEMAND OPERATIONS ON PRIORITY WITH OPTIMISATION OF ENERGY CONSUMPTION FROM PRIME MOVER
2. APPLICANT (S)
NAME NATIONALITY ADDRESS
BEML LIMITED IN BEML Soudha, No 23/1, 4th Main S.R. Nagar, Bengaluru- 560027, Karnataka, India.
3. PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION:
[001] The present invention relates to the field of flow control valve and flow summation systems. The present invention in particular relates to a flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimisation of energy consumption from prime mover.
DESCRIPTION OF THE RELATED ART:
[002] During the loading operation of the hydraulic excavator, due to the height of the truck, the height of the boom lifting bucket relative to the ground is generally a fixed value, but the rotation angle changes with the loading.
[003] Therefore, for loading at different angles, the slewing and boom should match different speeds to coordinate the composite movements of the slewing and boom and improve the efficiency of loading.
[004] However, most of the current priority valves are of fixed throttle type. For small-angle loading, the swing often arrives in place first and the boom arrives later, and this situation usually causes the bucket to hit the truck; for large-angle loading, the boom often arrives in place first and the swing arrives later, which seriously affects the efficiency of loading.
[005] Reference may be made to the following:
[006] Publication No. CN103047214 relates to a proportional flow priority control valve of a hydraulic excavator. The valve comprises a valve body, a plunger piston, a control spring, an ejector rod, a spring and a valve core. An A port of the valve is connected to control pressure, and a choke is arranged on the valve core. When the rotation and the moving arm lifting are conducted together, the pressure which is input to the A port can be determined in accordance with the angle of the rotation and the height of the moving arm lifting, the opening of the opening of the valve core can be controlled, and different angles of the rotation, the rotation and the moving arm lifting can be coordinated.
[007] Publication No. US20130115037 relates to a hydraulic excavator includes a lower travel body, an upper swivel body, a cooling unit, and first and second exterior members. The cooling unit includes a first cooling device disposed facing the first exterior member, and a second cooling device disposed on a side of the first cooling device towards the second exterior member and in midway in an air channel between the second exterior device and a cooling fan. The second cooling device extends in a direction intersecting a direction in which the first cooling device extends.
[008] Patent No. US3430790 relates to an improved excavator, of the self-propelled type, mounted on Creeper tracks, wheels or the like, and comprising a boom by which a bucket is supported. Such excavators, which lare utilized under widely varying conditions and for the most different purposes-in general for all earthworks and in particular tor digging foundations, trenches and the like usually 'consist of a stationary frame connected 'with the Creeper tracks or wheels land carrying a turntable that can be rotated on an axis perpendicular to the ground surface, and whereon the boom is fitted, along with all required control devices, inclusive of the operator’s cab.
[009] Publication No. US2022325498 relates to a track-type loader machine includes a main frame, laterally spaced track roller frames, an equalizer bar pivotally mounted to the main frame and attached to the roller frames, a work implement movably connected to the main frame by a plurality of linkages, and at least one cross-slope actuator which connects one of the roller frames to the main frame. The at least one cross-slope actuator is configured to tilt the work implement and the plurality of linkages in conjunction with the main frame relative to a pivoting axis of the equalizer bar.
[010] Patent No. US4405281 relates to a hydraulic excavator, with a boom lower part, a boom upper part and a stick, for conversion to operation using a gripper with large ranges of action and lifting heights. A connecting piece which rigidly connects the boom upper part and the boom lower part is fastened to the boom upper part, and is formed with an eye. A hydraulic cylinder which serves to actuate the stick is swingably mounted on the eye by means of a bolt.
[011] Patent No. US4693384 relates to an articulated arm-type excavator machine has a boom which has a trolley track affixed onto its underside. A trolley member from which a pulley block can be suspended travels along this track, and is urged into an operator-selected position by a double-acting hydraulic cylinder. A power winch is mounted on the over carriage of the machine and a lifting cable runs from the winch, over the pulley block, to a lifting hook or other device.
[012] Publication No. WO2008075648 relates to a hydraulic drive device capable of efficiently performing leveling work by utilizing residual energy of pressurized oil in a hydraulic circuit, which energy has not attracted attention from conventional techniques. The hydraulic drive device for a hydraulic excavator has a boom cylinder, an arm cylinder, a main hydraulic pump for supplying pressurized oil to both the cylinders a directional control valve for boom and directional control valve for arm for respectively controlling the flow of the pressurized oil to both the cylinders and a tank oil path for connecting the directional control valve for arm to a hydraulic oil tank. The hydraulic drive device further has a flow rate control valve capable of selectively closing a tank oil path.
[013] Publication No. CA2175409 relates to an excavator bucket linkage comprising a ternary link with first, second and third pivot connections and a follower link with first and second pivot connections. The first pivot connection of the ternary link is pivotally coupled to the rod end of the bucket actuating hydraulic cylinder. The second pivot connection of the ternary link is pivotally coupled to the excavator bucket. In addition, the excavator bucket is pivotally connected to the dipper stick. The follower link has a first pivot connection that is pivotally connected to the dipper stick and a second pivot connection that is pivotally connected to the third pivot connection of the ternary link.
[014] Publication No. US2016318542 relates to a steering column assembly configured to couple to a steering wheel is provided. The assembly includes a steering column shaft having a first end and a second end, the second end configured to couple to the steering wheel. The assembly also includes an intermediate shaft coupled to the steering column shaft first end. The assembly further includes a steering input pinion coupled to the intermediate shaft. The assembly yet further includes a counter rotation mechanism configured to counter rotate rotational movement of the steering column assembly such that the steering wheel does not rotate.
[015] Publication No. CN117962988 relates to a wheel excavator steering control system and method. The system comprises a controller, an electromagnetic reversing valve and a proportional reversing valve. The electromagnetic directional valve and the proportional directional valve are electrically connected to the output end of the controller; the input end of the electromagnetic reversing valve is connected with the main pump through an oil way, and the output end of the electromagnetic reversing valve is connected with the steering gear through an oil way.
[016] Publication No. CN105691447 relates to a full-hydraulic steering system for a large-tonnage mining dump vehicle. A constant-pressure variable pump of the full-hydraulic steering system is connected to a hydraulic oil tank through an oil suction filter, an outlet of the constant-pressure variable pump is connected with a one-way valve through a high-pressure filter, and an outlet of the one-way valve is connected with an inlet of a safety valve, HP openings of two flow amplifiers and an oil opening of an energy storage device; and meanwhile the oil opening of the energy storage device is connected with an oil opening in one end of an unloading solenoid valve, an oil opening in the other end of the unloading solenoid valve, an outlet of the safety valve and HT openings of the flow amplifiers are all back connected with the hydraulic oil tank, and the flow amplifiers are connected with a left steering oil cylinder and a right steering oil cylinder.
[017] Publication No. CN105752153 relates to a hydraulic steering system for an off-road mining dump truck. The hydraulic steering system comprises a hydraulic oil tank, an oil suction filter, an oil return filter, a constant-pressure variable pump, an oil pressure filter, a steering valve bank, an energy accumulator, a flow amplifier I, a flow amplifier II, a right steering cylinder, a left steering cylinder, a steering gear I, a steering gear II, a transfer mechanism and a direction control mechanism. Ports P and ports LS of the flow amplifier I and the flow amplifier II are respectively connected to ports P and ports LS of the steering gear I and the steering gear II, ports L and ports R of the flow amplifier I and the flow amplifier II are respectively connected to ports R and ports L of the steering gear I and the steering gear II, and input shafts of the steering gear I and the steering gear II are respectively connected with the direction control mechanism by the transfer mechanism.
[018] Publication No. CN115075330 relates to a bidirectional driving steering control system and method and an excavator. The system comprises a steering gear, a front wheel steering oil cylinder, a rear wheel steering oil cylinder, a front wheel oil cylinder position sensor, a rear wheel oil cylinder position sensor, a steering mode selection switch, a whole machine controller and the like. The vehicle has multiple steering modes of front and rear wheel steering and four-wheel steering, so that the vehicle can move and steer more freely in a limited space.
[019] Publication No. RU2131497 relates to device has prime-mover with digging implement secured on prime-mover for rotation. When digging trench whose depth does not depend on irregularities of surface along which prime-mover drives, sensor is secured on prime-mover to receive reference signal.
[020] Publication No. IN2205/KOLNP/2009 relates to a hydraulic drive system for a hydraulic excavator, which makes it possible to efficiently perform grading work by using residual energy of pressure oil in a hydraulic circuit although no attention has been paid to the residual energy in conventional technologies. A hydraulic drive system for a hydraulic excavator is provided with a boom cylinder 1 and arm cylinder 2, a main hydraulic pump 4 for feeding pressure oil to both the cylinders 1,2, a directional control valve 7 for a boom and directional control valve 8 for an arm to control flows of pressure oil to be fed to the boom cylinder 1 and arm cylinder 2, respectively, and a reservoir line 8c connecting the directional control valve 8 for the arm with a working oil reservoir 6.
[021] Publication No. EP0480037 relates to an operating device for the traveling and working machines of the excavator, which is provided with a separation-mode release switch capable of temporarily changing over a separation mode providing a low working speed of an actuator to a standard mode allowing a high working speed when the working speed of the actuators is desired to be increased during working performed in the low-working-speed separation mode in which the operability of the actuators is an important factor.
[022] Publication No. EP2103747 relates to a hydraulic drive system for a hydraulic excavator, which makes it possible to efficiently perform grading work by using residual energy of pressure oil in a hydraulic circuit although no attention has been paid to the residual energy in conventional technologies. A hydraulic drive system for a hydraulic excavator is provided with a boom cylinder 1 and arm cylinder 2, a main hydraulic pump 4 for feeding pressure oil to both the cylinders 1,2, a directional control valve 7 for a boom and directional control valve 8 for an arm to control flows of pressure oil to be fed to the boom cylinder 1 and arm cylinder 2, respectively, and a reservoir line 8c connecting the directional control valve 8 for the arm with a working oil reservoir 6.
[023] Publication No. CN111501871 relates to an excavator hydraulic system and an excavator. The excavator hydraulic system comprises an actuating element, a hydraulic pump and a pile-up valve. The actuating element comprises a rotary hydraulic motor, a walking hydraulic motor, a bucket operating cylinder, a bucket rod operating cylinder and a swing arm operating cylinder, the hydraulic pump is a four-unit pump, and the four-unit pump comprises a first pump body, a second pump body, a third pump body and a fourth pump body, wherein the first pump body, the second pump body, the third pump body and the fourth pump body are connected in series, an oil outlet of the first pump body communicates with an oil inlet of the rotary hydraulic motor, an oil outlet of the second pump body communicates with an oil inlet of the bucket rod operating cylinder, and oil outlets of the third pump body and the fourth pump body separately communicate with an oil inlet of the pile-up valve, and operating oil passages of the walking hydraulic motor, the bucket operating cylinder and the swing arm operating cylinder separately communicate with an oil outlet of the pile-up valve.
[024] Patent No. US4470260 relates to an open center, load sensing hydraulic system is disclosed which contains a primary work circuit and a secondary work circuit. A fixed displacement pump is fluidly connected between a reservoir and both the primary and secondary work circuits for supplying pressurized fluid thereto. The primary work circuit includes a control valve which regulates fluid flow from the pump to a primary hydraulic function and which includes a feedback mechanism connected thereto. The secondary work circuit includes a manually operable control valve for regulating fluid flow from the pump to a secondary hydraulic function.
[025] Publication No. KR20010061822 relates to an arm cylinder regenerative oil hydraulic circuit controller of an excavator is provided to prevent the cavitation of an arm cylinder on arm crowd motion and to control an arm cylinder regenerative oil passage not to lower the efficiency of excavation requiring heavy loads relatively.
[026] Publication No. KR20100042152 relates to an oil-hydraulic circuit for the work equipment of an excavator is provided to increase smooth operation speed and to improve workability by preventing a flow rate from leaning upon the low tension side. An oil-hydraulic circuit for the work equipment of an excavator comprises a valve. The valve is installed on a flow path.
[027] Publication No. US3515224 relates to a hydraulic control for a vehicle having a blade, a tilt cylinder, lift cylinders for positioning the blade in relation to the ground, and valves in the lift cylinders for relief of fluid pressure and for allowing by-pass of the fluid. The valves in each lift cylinder are connected by a pin and the relief and by-pass action is actuated by reason of one or the other extremity of the valve mechanism striking a portion of the cylinder.
[028] Publication No. KR20040024089 relates to a flow joining device of an option device of an excavator is provided to maximize the optimal efficiency of the option device and the space utilization of a main control valve and the excavator by supplying hydraulic oil to the option device by additionally installing an inner passage using a joining spool in the main control valve of an option spool.
[029] Patent No. US6267141 relates to a hydraulic directional control valve with a regulating balance comprising a plunger which can be displaced in a housing under the action of a differential pressure (DELTAp) between the intake pressure (P) and the highest load pressure (LS), and which is designed to open, in proportion to this differential (DELTAp), a lateral orifice of the housing linked to a working orifice (A, B) of the directional control valve; the wall of the housing and/or the plunger is provided with a calibrated passage linking the intake of fluid at pressure (P) and the lateral orifice when the plunger is pushed back into an end position by the pressure (LS) exceeding the intake pressure (P); consequently, in spite of the excess value of the pressure (LS) intended to inhibit operation of the directional control valve, hydraulic fluid is delivered to the lateral orifice at a low rate and allows the hydraulic receiver controlled by the hydraulic directional control valve to be displaced at a low rate.
[030] The article entitled “Optimization of energy regeneration of hybrid hydraulic excavator boom system” by Ying-Xiao Yu, Kyoung Kwan Ahn, University of Ulsan, San 29, Muger 2dong, Nam-gu, Ulsan 680-764, Republic of Korea; Energy Conversion and Management Volume 183, Pages 26-34, 7 June 2018 talks about a novel energy regeneration boom system. A variable displacement hydraulic motor and flow control valve were used to regulate the torque and speed of the generator, and to regulate flow through the hydraulic motor. A control strategy was proposed to calculate the optimal displacement of the hydraulic motor. The hydro-mechanical efficiency map and volumetric efficiency map were used to estimate the speed and torque of the generator instead of using speed and torque sensor. The resulting energy regeneration efficiency ranged from 33.8% to 57.4%, which cannot be realized in conventional boom system. Compared with conventional energy regeneration boom system, the improvement of energy regeneration efficiency with the proposed system was 3.2% to 4.1% for low and moderate velocities.
[031] The article entitled “Energy flow analysis of excavator system based on typical working condition load” by Su Deying; Hou Liang; Shaojie Wang; Xiangjian bu; Xiaosong Xia; Electronics 11(13):1987; June 2022talks about the accurate energy flow results are the premise of excavator energy-saving control research. Only through an accurate energy flow analysis based on operating data can a practical excavator energy-saving control scheme be proposed. In order to obtain the excavator’s accurate energy flow, the excavator components’ performance and operating data requirements are obtained, and the experimental schemes are designed to collect it under typical working conditions. The typical working condition load is reconstructed based on wavelet decomposition, harmonic function, and theoretical weighting methods. This paper analyzes the excavator system’s energy flow under the typical working condition load. In operation conditions, the output energy of the engine only accounts for 50.21% of the engine’s fuel energy, and the actuation and the swing system account for 9.33% and 4%, respectively.
[032] The article entitled “A novel approach for the energy recovery and position control of a hybrid hydraulic excavator” by Prabhat Ranjan, Gyan Wrat, Mohit Bhola, Santosh Kr. Mishra, J. Das; ISA Transactions Volume 99, Pages 387-402, April 2020 talks about the heavy earth moving machineries (HEMM) like hydraulic excavator play a major role in construction and mining industries. In this context, the energy saving strategies in hydraulic excavator needs to be addressed considering its vital importance. Since the hydraulic excavators are subjected to heavy loads, hence the opportunity to harness the potential gravitational energy (GPE) remains a key area which can be effectively explored in order to minimize the energy consumption in consideration with hydraulic excavator. In the projected system, the potential energy is stored as pressure energy in hydro-pneumatic accumulator. The upward movement of the boom is executed with the help of prime mover during the starting of the first duty cycle. In the latter duty cycles, the stored pressurized energy is utilized together with the prime mover energy capable to execute the upward movement of the boom. The position of the boom cylinder is controlled by using the conventional PID controller using proportional flow control valve (PFCV) and accumulator. The error between the actual position and demand position of the linear actuator is minimized along with attainment of superior controlled performance while utilizing Model Predictive Controller (MPC). The pressurized accumulator with PFCV has been utilized to cater the different position demands.
[033] The article entitled “Energy-saving in excavators with application of independent metering valve” by Kyujeong Choi, Jaho Seo; Yongyun Nam & Kyeong Uk Kim ;Journal of Mechanical Science and Technology, Volume 29, pages 387–395, 15 January 2015 talks about the independent metering valve to excavator hydraulic systems in order to verify its effect on energy reduction in excavators through flow regeneration. The structure and modes of independent metering valve were introduced. Then, an excavator hydraulic system was modeled with independent metering valve configuration. Simulations compared power consumption of pump between excavator hydraulic systems with a conventional main control valve (MCV) and independent metering valve configuration (IMV).
[034] The article entitled “A positive flow control system for electric excavators based on variable speed control” by Shengjie Fu; Zhongshen Li; Zhongshen Li; Tianliang Lin; Qihuai Chen; Haoling Ren; Applied Sciences 10(14):4826; July 2020 talks about the energy conservation and emission reduction of construction machinery are the focus of current research. The traditional excavator, whose hydraulic pump is driven by the engine, has high fuel consumption and emissions. Furthermore, it is difficult to match the working point of the engine to that of the hydraulic pump. Current pure electric drive technology has the advantages of zero pollution and low noise, and the motor used has the advantages of fast response and a wide speed range. Based on the characteristics of the pure electric drive technology, a positive flow system based on variable speed constant displacement instead of a variable displacement pump for pure electric construction machinery is put forward to realize the flow-matching of the whole machine. The basic structure and working principle were introduced. The control process was analyzed. The controllability and energy saving of the proposed system were tested through simulation and experimental analysis. The research results showed that the controllability of the proposed positive flow system was comparable to that of the traditional throttling speed-regulating control system. The energy-saving efficiency of the proposed positive flow system is increased by 35.2% compared to that of the tradition control system.
[035] The article entitled “Design and analysis of a flow-control valve with controllable pressure compensation capability for mobile machinery” by Wang Bo; He Liu; Yunxiao Hao; Long Quan; Yunwei Ryan Li; Bin Zhao; IEEE Access PP(99):1-1; July 2021 talks about the problems of low flow control accuracy, small flow control difficulty, and limited flow range in the traditional pressure-compensation flow-control valve. For this, a method of continuous control pressure drop operated to control flow-control valve flow is proposed. And the precise control of small flow is realized by reducing the pressure drop operated. In the research, the flow-control valve with controllable pressure compensation capability (FVCP) was designed firstly and theoretically analyzed. Then the sub-model model of PPRV and traditional flow-control valve were established and verified through experiments respectively. Finally, the accurate co-simulation model of the FVCP was established. The continuous control characteristics of pressure drop ?prated, the flow characteristics of FVCP, and the influence of different parameters d2 were studied. The research results demonstrate that, compared with the traditional flow-control valve, the designed FVCP can adjust the compensation pressure difference in the range of 0~1.7 MPa in real-time. And the flow rate can be altered within the range of 44%~100% of the rated flow. The diameter d2 of the console shoulder has almost no effect on the compensator operating characteristics.
[036] The article entitled “Excavators with its cylinder components” by Fujian Tongzhou Machinery Co.,Ltd. ; tz-cylinder; Dec 30, 2022 talks about the excavator consists of a boom cylinder, bucket with excavator hydraulic cylinder, a digger with undercarriage. These components are connected to the cab located on the rotating house. Most excavator cabs can be rotated 360 degrees to improve visibility. Depending on the manufacturer and the nature of the project, the excavator can be equipped with tracks or wheels. Excavators come in various sizes and grades, weighing up to 180,000 pounds. The excavator has many other accessories that can replace the digging bucket to diversify the machine. Excavators can be used for many different jobs by replacing buckets through augers, drills, rippers, or rakes. A hydraulic cylinder is a tube that uses hydraulic pressure to produce linear drive. Meanwhile, it will include hydraulic boom cylinder, arm cylinder and bucket cylinder. Basically, the pressure of the hydraulic fluid forces the piston to move in a push or pull motion. Depending on the application and industry, excavator hydraulic cylinder can be called hydraulic actuators or hydraulic pistons. The excavator hydraulic cylinder is divided into single acting or double acting. If only one chamber is pressurized by hydraulic fluid, it is single acting, otherwise it is double acting.
[037] The article entitled “Energy and operation characteristics of electric excavator with innovative hydraulic-electric dual power drive boom system” by Yunxiao Hao, Long Quan, Shufei Qiao, Lei Ge, Zepeng Li, And Bin Zhao; ieeexplore; 26 July 2023 talks about the existing electric excavators, the energy efficiency of the hydraulic system is less than 30% due to a large amount of throttling loss and waste of potential energy. In order to improve excavator energy efficiency, an electric excavator scheme using a hydraulic-electric dual-power drive boom system is proposed. A linear actuator, including electro-mechanical unit and hydraulic unit, was adopted in the boom system. The boom velocity is controlled by the electro-mechanical unit instead of hydraulic valve to reduce throttling loss. The non-rod chamber of the linear actuator is connected to a hydraulic accumulator to reutilize boom gravitational potential energy. In addition, when the boom and other devices are operated together, the throttling loss caused by load difference of multi-actuators can be reduced because the linear actuator can compensate for the pump pressure.
[038] The article entitled “Energy saving solutions for a hydraulic excavator” by Andrea Bedotti; Federico Campanini; Mirko Pastori; Luca Ricco; Paolo Casoli; Energy Procedia 126:1099-1106; September 2017 talks about the aid of mathematical tools energy saving solutions for an excavator equipped with a load sensing hydraulic system. A comprehensive energy analysis was conducted through the excavator model to highlight the energy dissipations along the system. Different solutions to reduce losses and improve fuel saving including energy recovery from boom and arm and the introduction of a second pump in the flow generation unit were identified and investigated in detail. Finally, combining the proposed solutions, a new hydraulic hybrid excavator concept was obtained with a 15% of fuel saving.
[039] The article entitled “Comparing single- and double-acting hydraulic and pneumatic cylinders” by W.C. Branham, Inc. ; blog.wcbranham; 2024 talks about the actuators play a crucial role in various industries, enabling the smooth and efficient movement of machinery components. Among these, double-acting cylinders stand out for their ability to provide control in both forward and backward movements. There are also differences when it comes to hydraulic and pneumatic powering of cylinders. Let’s start by exploring the real-world applications, design options, and control considerations of double-acting cylinders. A double-acting cylinder alternates cycles of pressurized fluid to both sides of the piston and creates extend and retract forces to move the piston rod, permitting more control over the movement. Using a control system made up of a 2-, 3-, 4- way position valve would be required to achieve the desired movement for your application.
[040] Conventionally, there is no provision to facilitate, all four main pumps flow to an individual actuator/ aggregate, without implementing segmented kind of Direction control valves in hydraulic circuit.
[041] There is no such existing technology, available for the flow summation and distribution on demand to facilitate all Individual operations and during all kind of combined operations. Since the Prime mover power is optimized with pump capacity, further there is no provision to increase the main pumps capacity in place of 190cc/rev. and no addition of main pump is recommended as per the first principles.
[042] By increasing the prime mover capacity will result in consuming more energy/fuel and it leads to higher running cost/hour and brings down the efficiency of the equipment.
[043] By changing the hydraulic linear actuators dimensions, it's possible to achieve the standard cycle timings without compromising the pumps, but it will affect the working profile of the equipment or load lifting capacity.
[044] Thus there needed segmented design in main direction control valves and each segment with one dedicated main pump flow can facilitate at least 4 individual operations, one after the other.
[045] This kind of segmented design of flow summation system, solves the exactly issue, with the existing prime mover itself.
[046] In order to overcome above listed prior art, the present invention aims to provide a flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimisation of energy consumption from prime mover. The invention operates, all the operations in excavator, using this available four main pumps flow.
OBJECTS OF THE INVENTION:
[047] The principal object of the present invention is to provide a flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimisation of energy consumption from prime mover.
[048] Another object of the present invention is to operate, all the operations in excavator, using this available four main pumps flows.
[049] Yet another object of the present invention is to provide cost effective system that increases the efficiency of the equipment without changing the pump capacity, prime mover capacity and linear or rotary actuators in hydraulic system.
SUMMARY OF THE INVENTION:
[050] The present invention relates to the flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimisation of energy consumption from prime mover.
[051] 180 ton class excavator hydraulic system, consists of four variable displacement axial piston pumps to facilitate the operations like boom rise and down, arm in and out, bucket curl and dump, steering/travel forward, reverse and counter steering. This hydraulic system is positive control closed center open loop load sensing system with electronic load limiting control for efficient use of prime mover power.
[052] Two main direction control valves have been engineered in hydraulic system to ensure the positive control closed center open loop load sensing system. Each variable displacement axial piston pump will deliver max.190cc/rev and the flow required is very high to achieve the standard cycle time during boom raise, arm out and bucket curl operation and in special cases like loading shovel it is required to operate the bottom dump cylinders to unload the material from loading shovel bucket. It is also required to implement common hydraulic system for basic hydraulic excavator which is suitable for both loading shovel or backhoe configurations. Hydraulic system consists of 2 Direction control valves. Each direction control valve consists of 8 spools and using each spool 2 individual operations are possible. Each spool of direction control valve is designed to handle main pump flow of 190cc/rev. Further it is required to design the main control valve spools to facilitate on demand operations on priority while operating all individual operations and as well as all combination of various operations like boom & bucket, arm & travel etc.
BREIF DESCRIPTION OF THE INVENTION
[053] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[054] Figure 1 shows the detail flow chart of segmented design direction control valve according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION:
[055] The present invention provides flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimization of energy consumption from prime mover.
[056] 180 Ton class excavator hydraulic system, consists of four variable displacement axial piston pumps to facilitate the operations like boom rise and down, arm in and out, bucket curl and dump, steering/travel forward, reverse and counter steering. This hydraulic system is positive control closed center open loop load sensing system with electronic load limiting control for efficient use of prime mover power.
[057] Two main direction control valves have been engineered in hydraulic system to ensure the positive control closed center open loop load sensing system. Each variable displacement axial piston pump will deliver max.190cc/rev and the flow required is very high to achieve the standard cycle time during boom raise, arm out and bucket curl operation and in special cases like loading shovel it is required to operate the bottom dump cylinders to unload the material from loading shovel bucket. It is also required to implement common hydraulic system for basic hydraulic excavator which is suitable for both loading shovel or backhoe configurations. Hydraulic system consists of 2 direction control valves. Each direction control valve consists of 8 spools and using each spool 2 individual operations are possible. Each spool of direction control valve is designed to handle main pump flow of 190cc/rev. Further it is required to design the main control valve spools to facilitate on demand operations on Priority while operating all individual operations and as well as all combination of various operations like boom & bucket, arm & travel etc.
[058] The flow control valve in hydraulic system, which can make use of all 4-pump flows, to facilitate all the individual operations & as well as all combination of various operations like boom & bucket, arm & travel etc., with available 4-pump flow without affecting the performance and cycle timings of excavator.
[059] Following operations are carried out in 180-ton class Hydraulic Excavator as mentioned below.
1. Boom raise and down by double acting linear actuators called Boom cylinders.
2. Arm in and out by double acting linear actuators called arm cylinders.
3. Bucket Curl and Dump by double acting linear actuators called Bucket cylinders.
4. Loading shovel bucket throat opening and closing by double acting linear actuators called Bottom dump cylinders
5. Travel /steering forward and reverse, and counter steering operations by bi-directional hydraulic motors.
[060] Specific/dedicated main control valve spool will facilitate the main pump flow to the required linear actuators or to the rotary actuators on demand during individual operation or all kind of combined operations. Each main pump will deliver Max. 190cc/rev. The requirement of flow for each individual operation is unique, although there is no dedicated pump is available to perform each individual operation.
[061] In case of individual operations like boom raise, arm out and bucket curl, it requires summation of all 4 main pump flow to ensure the standard cycle timings. Since flow requirement of these individual applications are very high, single pump flow is not sufficient enough to operate the above-mentioned operations. In case of combined operations like arm out and bucket curl, its not possible to provide all the 4 pumps flow to an individual application. In these types of cases, its required to split the pump flow in the ratio of 3:1 or 2:2 on priority, without compromising the cycle timings and performance of the equipment. Although main control valve is having limited provisions or partitions, for directing the oil flow to the particular aggregates. In order to provide the sufficient flow to various combination of operations, flow control valve has to be designed as follows, each control valve consists of 8 spools and the same was divided into 2 segments, A & B.
[062] Segment A with first 4-spools are facilitating the 4 different individual operations with one dedicated main pump flow(P1). Similarly, Segment B of the control valve consists of another 4 spools and facilitating other 4 different individual operations with second dedicated main pump flow (P2). Totally, in hydraulic system, 2 main control valves with 4 separate segments will facilitate 16 different individual operations or 4 combined operations at a time, with available 4 main pump flows, without compromising the cycle timings and performance of the equipment. It is mandatory that, provision to be made in the main direction control valve to facilitate all 4 pumps flow to the individual operations and minimum one pump flow to each hydraulic aggregate during combined operations, to achieve the standard cycle timings. The detail flow chart of segmented design Direction control valve is shown in figure 1.
[063] Spool 1,2,3 & 4 are placed in series in segment-1 of main direction control valve RH, so that hydraulic oil delivered by pump-1 will enter inside spool-1 and flows to spool-2,3 &4 accordingly. Spools are placed in order of 1 to 4 as per the priority. The first priority is given to spool-1, second priority for spool-2, third priority is for spool-3 and fourth priority is for spool-4 related applications.
[064] In segment-3 of main direction control valve LH, is identical / same as mentioned above (Segment-1), but only difference is, in place of pump-1, pump-3 flow will be used to facilitate all the 4 spools of segment-3.
[065] Spool 8,7,6 & 5 are placed in series in segment-2 of main direction control valve RH, so that hydraulic oil delivered by pump-2 will enter inside spool-8 and flows to spool-7,6 & 5 accordingly. Spools are placed in order of 8 to 5 as per the priority. The first priority is given to spool-8, second priority for spool-7, third priority is for spool-6 and fourth priority is for spool-5 related applications.
[066] In segment-4 of main direction control valve LH, is identical / same as mentioned above (segment-2), but only difference is, in place of pump-2, pump-4 flow will be used to facilitate all the 4 spools of segment-4.
[067] When the prime mover is, on condition and equipment is not in operation, in this case, hydraulic oil will enter inside spool-1 of segment-1 of main direction control valve RH and flows to Spool 2,3 & 4 and further oil will go to the hydraulic tank. Since equipment is not in operation, there is no hydraulic oil requirement or no demand from spool 1 to 4 of main direction control valve RH. The same concept is extendable for segment-2, segment-3 & segment -4 of main direction control valves, when the equipment is not in operation. Hence pump-2, pump-3 & pump-4 oil goes to hydraulic tank.
[068] When the prime mover is, on condition and equipment is in operation, in this case, hydraulic oil delivery from pump P1, will enter inside spool-1 of segment-1 of main direction control valve RH and it will check the demand from spool-1 on priority. If there is a demand, oil will flow to spool-1 and other spools, i.e., 2, 3 & 4 will not get oil flow from pump P1.
[069] Similarly, hydraulic oil delivery from pump p2, will enter inside spool-8 of segment-2 of main direction control valve RH and it will check the demand from spool-8 on priority. If there is a demand, oil will flow to spool-8 and other spools, i.e. 7, 6 & 5 will not get oil flow from pump P2.
[070] In similar way, hydraulic oil delivery from pump p3, will enter inside spool-1 of segment-3 of main direction control valve LH and it will check the demand from spool-1 on priority. If there is a demand, oil will flow to spool-1 and other spools, i.e., 2, 3 & 4 will not get oil flow from pump P3.
[071] Similarly, hydraulic oil delivery from pump P4, will enter inside spool-8 of segment-4 of main direction control valve LH and it will check the demand from spool-8 on priority. If there is a demand, oil will flow to spool-8 and other spools, i.e., 7,6 & 5 will not get oil flow from pump P4.
[072] As explained above, the oil flow from all the 4 pumps, will ensure the sufficient oil flow to the each of the operations performed individually and minimum one pump flow is assured for each of the operations performed combinedly. For example, during boom rise, when performed individually, the boom cylinder receives oil flow from pumps as mentioned below, 1) pump 1 oil flow, through spool-1 of segment-1. 2), Pump 2 oil flow through spool-5 of segment-2, 3), pump 3 oil flow through spool-1 of segment-3 and lastly, 4) pump 4 oil flow through spool-5 of segment-4.
[073] During all the other remaining operations, when performed individually, the oil flow can easily be understood referring to the flow chart given below.
[074] When operations are performed combinedly, for example, arm out with bucket curl & travel forward (3 operations at a time), the oil flow is distributed as follows, 1) pump 1 oil flow, through spool-2 of segment-1 will flow to bucket curl operation. 2) Pump 2 oil flow through spool-7 of segment-2 will flow to travel motor RH for forward operation, 3) pump 3 oil flow through spool-3 of segment-3 will flow to travel motor LH for forward operation and lastly 4) pump 4 oil flow through spool-8 of segment-4 will flow to arm out operation .
[075] During all the other remaining operations, when performed combinedly, the oil flow can easily be understood referring to the flow chart given below.
[076] With this kind of hydraulic system, one dedicated main pump flow is available for each operation, when performed combinedly and 4 dedicated main pump flows are available for each of the operations, when performed individually. This is possible, only by implementing segmented kind of direction control valves in hydraulic circuit or system and the uniqueness of this invention is in “the Flow summation and distribution of oil flows for both individual and combined operations of the heavy duty excavator through segmented kind of direction control valve”.
[077] The segmented direction control valves ensures all the four main pumps flow to each Hydraulic aggregate during individual operations and minimum one pump flow, during any type of combined operation. The system is most cost effective and increases the efficiency of the equipment without changing the pump capacity, prime mover capacity and linear or rotary actuators in hydraulic system.
[078] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.
,CLAIMS:WE CLAIM:
1. A flow control valve and flow summation systems comprises two main control valves with 4 separate segments will facilitate 16 different individual operations or 4 combined operations at a time, with available 4 main pump flows, without compromising the cycle timings and performance of the equipment characterized in that segment A with first 4-spools facilitating the four different individual operations with one dedicated main pump flow(P1) and segment B of the control valve characterized in that another 4 spools and facilitating other 4 different individual operations with second dedicated main pump flow(P2) wherein provision to be made in the main direction control valve to facilitate all 4 pumps flow to the individual operations and minimum one pump flow to each hydraulic aggregate during combined operations, to achieve the standard cycle timings.
2. The spools, as claimed in claim 1, wherein the position of spool includes-
a) Spool 1,2,3 & 4 are placed in series in Segment-1 of Main direction control valve RH, so that Hydraulic Oil delivered by Pump-1 will enter inside Spool-1 and flows to spool-2,3 &4 accordingly.
b) In Segment-3 of Main Direction control valve LH, is identical / same as mentioned above (Segment-1) and Pump-3 flow will be used to facilitate all the 4 spools of Segment-3.
c) Spool 8,7,6 & 5 are placed in series in segment-2 of main direction control valve RH, so that hydraulic oil delivered by pump-2 will enter inside Spool-8 and flows to spool-7,6 & 5 and first priority is given to Spool-8, Second Priority for Spool-7, Third Priority is for Spool-6 and fourth priority is for Spool-5 related applications.
d) In Segment-4 of Main Direction control valve LH, is identical / same as mentioned above (Segment-2), but only difference is, in place of Pump-2, Pump-4 flow will be used to facilitate all the 4 spools of Segment-4.
3. The flow control valve and flow summation systems, as claimed in claim 1, wherein the flow control valve and flow summation systems in high end excavators to facilitate on demand operations on priority with optimisation of energy consumption from prime mover
4. The flow control valve and flow summation systems, as claimed in claim 1, wherein spools are placed in order of 1 to 4 following first priority is given to Spool-1, Second Priority for Spool-2, Third Priority is for Spool-3 and fourth priority is for Spool-4 related applications.
5. The flow control valve and flow summation systems, as claimed in claim 1, wherein when the prime mover is, on condition and equipment is not in operation, hydraulic oil will enter inside Spool-1 of Segment-1 of Main direction control valve RH and flows to Spool 2,3 & 4 and further oil will go to the Hydraulic tank, there is no Hydraulic oil requirement or No demand from spool 1 to 4 of Main direction control valve RH.
6. The flow control valve and flow summation systems, as claimed in claim 1, wherein when the prime mover is, on condition and Equipment is in Operation, Hydraulic Oil delivery from Pump P1, will enter inside Spool-1 of Segment-1 of Main direction control valve RH and it will check the demand from spool-1 on priority and if there is a demand, oil will flow to spool-1 and other spools, i.e., 2, 3 & 4 will not get oil flow from Pump P1, similarly, Hydraulic Oil delivery from Pump P2, will enter inside Spool-8 of Segment-2 of Main direction control valve RH and it will check the demand from spool-8 on priority and if there is a demand, oil will flow to spool-8 and other spools, i.e. 7, 6 & 5 will not get oil flow from Pump P2.
7. The flow control valve and flow summation systems, as claimed in claim 1, wherein hydraulic Oil delivery from Pump P3, will enter inside Spool-1 of Segment-3 of Main direction control valve LH and it will check the demand from spool-1 on priority and if there is a demand, oil will flow to spool-1 and other spools, i.e., 2, 3 & 4 will not get oil flow from Pump P3.
8. The flow control valve and flow summation systems, as claimed in claim 1, wherein hydraulic oil delivery from pump P4, will enter inside Spool-8 of Segment-4 of Main direction control valve LH and it will check the demand from spool-8 on priority and if there is a demand, oil will flow to spool-8 and other spools, i.e., 7,6 & 5 will not get oil flow from Pump P4.
9. The flow control valve and flow summation systems, as claimed in claim 1, wherein, the oil flow is distribution when operations are performed combinedly is as follows-
a) Pump 1 oil flow, through spool-2 of segment-1 will flow to Bucket curl operation,
b) Pump 2 oil flow through spool-7 of segment-2 will flow to Travel Motor RH for forward operation,
c) Pump 3 oil flow through spool-3 of segment-3 will flow to Travel Motor LH for forward operation and lastly,
d) Pump 4 oil flow through spool-8 of segment-4 will flow to Arm out operation.