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Pump control device for construction machine

A pump control device and construction machinery technology, applied in the field of hydraulic circuits, can solve the problems of reduced workload and ineffective use of prime movers, and achieve the effect of preventing lag

Active Publication Date: 2013-05-01
NIHON KENKI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, in the region where the discharge pressure of the third hydraulic pump is higher than the maximum pressure P30, the output of the prime mover cannot be effectively used, and there is a problem that the workload decreases.

Method used

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  • Pump control device for construction machine
  • Pump control device for construction machine
  • Pump control device for construction machine

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Experimental program
Comparison scheme
Effect test

no. 1 Embodiment approach

[0037] Below, according to Figure 1 to Figure 6 , Figure 10 Embodiments of the hydraulic circuit of the construction machine of the present invention will be described. In this embodiment, a hydraulic excavator is used as a construction machine, figure 1 is the overall hydraulic circuit diagram, figure 2 It is the hydraulic circuit diagram of the main parts, image 3 is a flowchart showing the flow of processing by the controller, Figure 4 is the discharge flow characteristic diagram of the first and second hydraulic pumps, Figure 5 is the discharge flow characteristic diagram of the third hydraulic pump, Figure 6 is the first and second pump torque reduction characteristics of the third pump discharge pressure, Figure 10 It is the external view of the hydraulic excavator.

[0038] First, according to Figure 10 The structure of the hydraulic excavator to which the present invention is applied will be described. The hydraulic excavator is roughly made up of the...

no. 2 Embodiment approach

[0057] In this second embodiment, on the basis of the first embodiment, an engine speed sensor 32 for detecting the actual engine speed and a configuration for sending the actual engine speed detected by the engine speed sensor 32 to the controller 29 are added. Line 33.

[0058] In addition, in the controller 29, based on the discharge pressure Pd3 of the third hydraulic pump detected by the pressure sensor 30 and the previously prepared table T2 showing the relationship between the discharge pressure Pd3 of the third hydraulic pump and the torque correction amount, , to determine the torque increase correction amount Td3 of the first and second hydraulic pumps. In addition, according to the engine target speed Ne set on the engine rotation control dial 37 and the relationship between the engine target speed Ne and the reference torque prepared in advance, Table T1, to determine the reference torque Te, according to the deviation (Nr-Ne) between the actual engine speed Nr det...

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Abstract

The present invention includes a torque correction amount output unit T2 for outputting the torque correction amounts of first and second pumps on the basis of the discharge pressure Pd3 of a third pump detected by pressure detection means 30; and a reference torque output unit T1 for outputting reference torque values of the first and second pumps on the basis of the target revolution speed of a prime mover specified by specifying means. On the basis of the output values Td3 and Te of the above output units, the torque control command pressure is calculated so that the input torques of the first and second pumps are increased. The calculated torque command instruction pressure is then supplied as external command pressure to the varying mechanism of the regulator used for the first and second pumps so as to prevent the input torques of the first and second pumps from being decreased more than necessary. As a result, even when three variable displacement hydraulic pumps are used with the discharge pressure of one of the hydraulic pumps reduced by a pressure reducing valve and further the input torques of the other two hydraulic pumps are decreased by that pressure, the engine output can be efficiently utilized, and the work rate dose not decrease.

Description

technical field [0001] The present invention relates to a hydraulic circuit having at least 3 hydraulic pumps driven by an engine installed in a construction machine such as a hydraulic excavator, and in particular to a pump control device for a construction machine, the pump control device controlling The oil discharge capacity of each hydraulic pump is such that the consumption torque generated with the driving of each hydraulic pump does not exceed the output horsepower of the engine, and the engine output is effectively used. Background technique [0002] As such prior art, there is, for example, the technology described in Patent Document 1. This prior art includes three variable capacity hydraulic pumps driven by one prime mover and multiple actuators. The oil discharge volumes of the first and second hydraulic pumps are based on the respective self-discharge pressures P1 and P2. And the discharge pressure P3 of the third hydraulic pump is controlled by the pressure P...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): F15B11/00E02F9/22F04B49/00F15B11/17
CPCE02F9/2285E02F9/2282E02F9/2292E02F9/2235E02F9/2296F04B17/05F15B11/02F15B11/17E02F9/22
Inventor 楢崎昭广石川广二有贺修荣
Owner NIHON KENKI CO LTD