Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2278—Hydraulic circuits
  • E02F9/2296—Systems with a variable displacement pump
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2221—Control of flow rate; Load sensing arrangements
  • E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
  • E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2246—Control of prime movers, e.g. depending on the hydraulic load of work tools
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D29/00—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto
  • F02D29/04—Controlling engines, such controlling being peculiar to the devices driven thereby, the devices being other than parts or accessories essential to engine operation, e.g. controlling of engines by signals external thereto peculiar to engines driving pumps

Definitions

• the present invention relates to a control device and a control method for a construction vehicle such as a wheel loader that mainly performs a loading operation.
• Fig. 7 shows a working machine control system using a variable displacement hydraulic pump in a conventional wheel loader mainly for loading.
• the engine E is controlled by the governor gV via the linkage £ i by operating the accelerator pedal ap.
• the output of the engine E is transmitted to the torque converter T and the gear train G.
• the output transmitted to the gear train G drives the variable displacement hydraulic pump PV.
• the amount of pressure oil in the variable displacement hydraulic pump PV is controlled by a variable displacement pump control valve pc via a servo cylinder SC.
• the packet operation by-lot valve AL is operated, the bucket main operation valve AV is operated, and the bucket A is rotated via the bucket cylinder AC. Tilt backward or dump forward.
• the boom operation pilot valve BL is operated, the boom main operation valve BV is operated, and the boom B is rotated through the boom cylinder BC to lift upward. Down or down.
• FIG. 8 shows a pressure-flow rate characteristic diagram of the variable displacement hydraulic pump in the conventional work machine control system described above.
• the hydraulic torque at high pressure is increased. Is limited to a necessary and sufficient amount.
• the hydraulic pump PV as shown in FIGS. 7 and 8 and the drive train power transmission device (torque converter T) distribute the engine E output.
• the decrease in power consumption due to hydraulic pressure is absorbed by the drive train as shown in Fig. 9, so the drive power increases and the ratio of the drive train output to the work machine output increases.
• vehicles that become larger and dig into soil, etc., impair workability That is, referring to FIGS. 8 and 9,
• the purpose of the present invention is to solve the above-mentioned problems. Disclosure of the invention
• the present invention provides an engine output characteristic in a loading work vehicle equipped with a variable displacement hydraulic pump for working machine operation and a torque converter for driving a vehicle.
• An electronically controlled governor that can be selected stepwise is provided, and the maximum capacity and output torque of the variable capacity pump are set in stages.
• Electromagnetic pilot valve, pump capacity detector, hydraulic pressure Along with the detector, a switch for selecting the output characteristics of the engine and the output characteristics of the variable capacitance pump (hereinafter referred to as the M-mode operation switch) was provided.
• an electronic gun controller that controls the engine output characteristics, and a variable pump that selects and sets the maximum capacity of the variable capacity bomb and the output torque characteristics. A controller is provided, and the M mode operation is performed. And Tsu by the selection of the scan I Tsu switch to control the size and distribution of the hydraulic output and the driving output, the improvement of workability.
• the maximum image setting of the electronically controlled governor according to the discharge pressure or output torque of the variable displacement hydraulic pump (hereinafter referred to as the regulation characteristic) Also, by lowering the engine torque setting, the torque fluctuation range of the torque converter can be reduced to reduce the torque fluctuation range. An excessive increase in power was prevented.
• a selection switch (hereinafter referred to as an L-mode operation switch) that can gradually select the setting of the force-off pressure of the discharge flow rate of the variable displacement pump in the above control device.
• the L-mode operation switch selection stage and the M-mode operation switch selection stage described above provide working machine power and drive power. This is to make it possible to select a power distribution with power in a matrix manner.
• FIG. 1 is a control system diagram of an embodiment of a control system for a loading work vehicle according to the present invention
• FIG. 2 is an explanatory diagram of a pressure-flow characteristic curve of a variable displacement pump PV
• FIG. (a), (b), (c) each M, mode and L, the mode combinations, the Micromax zeta mode and L z mode combination of M 3 mode and L 3 mode 4 (a) and 4 (b) are flow charts of the work implement control method according to the present invention
• FIG. 5 is a flow chart showing the hydraulic torque.
• 6 (a) and 6 (b) show the power distribution matrix between the working machine oil pressure L and the driving force M, respectively, for the control method for lowering the engine torque setting.
• FIGS. 7, 8, and 9 are explanatory drawings of conventional ones.
• FIG. 1 shows an embodiment of a control system for a loading work vehicle according to the present invention, which is the same as that of the conventional control system described with reference to FIG.
• the code is attached.
• An electronically controlled governor 10 whose output characteristics can be selected stepwise is mounted on the engine E, and an electronic governor controller 11 is provided. For the input signal of (4) Control the electronically controlled governor 10 accordingly.
• M-mode operation switch 42 M-mode selection signal from 2 Variable pump controller 41 1 is an electronic governor controller
• FIG. 2 shows an embodiment of the pressure-flow characteristic curve of the variable capacity pump PV.
• M mode operation switch 42 By operating the M mode operation switch 42, the M Multiple M modes, such as 1 mode, M2 mode, and M3 mode, can be set in stages, and the electronically controlled governor 10 adjusts them accordingly.
• the torque characteristics of engine E are shown in Figs. 3 (a), (b) and (c) as M1 and ⁇
• the working machine Hydraulic pressure can be set stepwise to multiple L modes such as L1, L2, and L3 modes.
• the maximum torque is obtained.
• click point B,, B 2, B 3 its oil pressure torque is Ri Do and T B 1, T B2, T B3 , respectively, the absorption preparative torque point bets torque co members data at that time the respective 3 B, B 2 ′, ⁇ 3 ′ in FIGS.
• Fig. 4 (a) shows that when the pump pressure is cut off when the working machine oil pressure is P Al (or P A2 , P A3 ) or higher, the hydraulic torque is T A , (or T A2 , T A3 ) shows the control flow of the electronically controlled governor 10 when the engine maximum rotation set is reduced when it is below.
• Fig. 4 (b) shows the hydraulic pressure of the work equipment. If the pump torque is cut off above P B1 (or P B2 , P B3) and the hydraulic torque falls below T B1 (or T B2 , T B3 ), This is a control flow of the electronically controlled governor 10 for controlling the target engine speed according to the following.
• the point A can be moved to the point B if the engine torque is reduced by k (TA1-T).
• FIG. 6 (C) shows that fluctuations in the torque absorbed by the torque converter when the work equipment hydraulic pressure is high, and the hydraulic torque and drive torque in the engine output selection stage are reduced.
• Fig. 6 (a) shows that the relationship between the magnitudes of the pressures is matched, and that the cutoff pressure of the discharge flow rate of the variable displacement pump PV can be selected stepwise.
• Fig. 6 (b) is a drawing explaining the effects of the working machine oil pressure L and the driving force M in the working machine system. Industrial applicability
• the present invention is constructed as described above, even if the hydraulic torque fluctuates when the variable capacity hydraulic pump is at a high pressure, the torque converter can suppress the fluctuation range of the absorption torque. As a result, it is possible to prevent an excessive increase in the driving force at the time of digging in the soil, so that the digging work can be carried out easily and efficiently.
• the power distribution of the working machine power and the driving force can be selected in a matrix, it is possible to easily respond to a variety of work forms. You.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Operation Control Of Excavators (AREA)
• Control Of Positive-Displacement Pumps (AREA)

Priority Applications (2)

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Publications (1)

Family

ID=16213642

Family Applications (1)

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Cited By (1)

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Citations (3)

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• 1990
  • 1990-07-18 JP JP2187869A patent/JP2520771B2/ja not_active Expired - Fee Related
• 1991
  • 1991-07-16 DE DE69123971T patent/DE69123971T2/de not_active Expired - Fee Related
  • 1991-07-16 EP EP91912321A patent/EP0539589B1/en not_active Expired - Lifetime
  • 1991-07-16 WO PCT/JP1991/000948 patent/WO1992001869A1/ja active IP Right Grant

Patent Citations (3)

Non-Patent Citations (1)

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