JPS6114447A - Output control system for diesel engine - Google Patents

Abstract

PURPOSE:To increase the fuel consumption efficiency by providing means for operating the engine rotation at the highest efficiency point of fuel consumption rate and means for determining the engine output to the engine rotation at the highest efficiency point. CONSTITUTION:Upon exceeding of the work load data over a setting level, engine output determining means 5 will determine the engine output corresponding with the speed level of working unit, while upon decision that the operator will not request the speed of working unit through working unit speed detecting means 3, the engine output is determined to the highest efficiency rotation operating means 4. Automatic engine output control means 7 will control the operation of engine rotation varying element 8 thus to vary the engine rotation to the control target level. Consequently, the fuel consumption efficiency is increased to save the fuel consumption.

Description

[Detailed description of the invention] [Industrial application field]

The present invention mainly relates to a system that detects engine loads corresponding to each of a traveling device and a working device in a construction machine and performs optimal output control of a diesel engine accordingly.

[Conventional technology]

In construction machinery, diesel engine output is controlled by mechanically detecting the fluctuating diesel engine speed using a governor weight, etc., and moving the control rank, since the diesel engine speed fluctuates as the load on the diesel engine increases or decreases. The fuel injection amount is controlled (increased or decreased) by changing the fuel delivery stroke. In addition, regarding load limitation, (a) For direct drive vehicles, when the load increases and the engine rotation decreases to near the limit, the operator will judge and limit the load by cutting off the power transmission, etc. Mitigation measures are being taken. (b) In power shift vehicles, the slip rate of the torque converter increases as the load increases, the engine rotation gradually decreases, and the output shaft rotation stops at maximum load (stall state). is being taught. (C) In hydrostatic vehicles (hydraulic drive type), the engine speed gradually decreases as the load increases, and this decreasing state is sensed and the pump discharge amount is reduced to reduce the vehicle speed). , reduce the load. At maximum load, the relief valve in the pump high-pressure line is opened to release pressure oil and reach the limit point. Therefore, direct drive vehicles depend solely on the skill and skill of the operator, and in vehicles equipped with a power shift transmission, incorrect speed gear switching and engine speed settings will result in a serious drop in efficiency. Furthermore, a vehicle equipped with a hydrostatic transmission has the disadvantage that it is not possible to obtain the optimum traveling speed and engine output (engine speed) when the engine speed variation factor is influenced by the hydraulic pressure of the working device. In this way, whether the engine output is controlled or the load is limited, the final result is to measure the fluctuations in engine speed and control based on this, so the engine operates at the highest efficiency point on the fuel efficiency curve. It is made difficult.

[Problems to be solved by the invention]

This invention was devised as a result of intensive research in view of the above circumstances, and its main purpose is to detect the load on the engine separately for the traveling equipment and the working equipment, and to give priority to the load on the working equipment to reduce the load on the engine. In other cases, the engine speed at the highest fuel efficiency point during work or driving is determined, and the engine output is continuously controlled to improve fuel efficiency.

[Means to solve the problem]

In order to achieve the above object, the present invention, as shown in the functional block diagram of FIG. 1, comprises: a running load measuring means 1 for measuring the load (horsepower consumption) of a running device; load measuring means 2; working equipment speed detecting means 3 for detecting the speed of the working equipment requested by the operator from the state of the control lever of the working equipment; and each maximum efficiency of the fuel efficiency in the case of full load or partial load of the diesel engine. Maximum efficiency rotation speed calculation means that has point data and inputs correction data such as the specific gravity of the fuel used and the temperature of the work site to calculate the engine rotation speed at the maximum efficiency point of the fuel efficiency during each work or driving. 4 and has . Each data obtained by these means 1 to 4 is input to the engine output determination means 5, and the engine output determination means 5 determines that the workability is 7":J if it exceeds the set value overnight. Determine the engine output (rotational speed) corresponding to the speed value of the equipment, and if it is determined by the work equipment speed detection means that the operator does not request the speed of the work equipment, the engine output is determined by the maximum efficiency revolution speed calculation means 4. The engine speed, which is the control target determined in this way, is displayed as a numerical value on the external display means 6 or as a specific operating instruction to the operator. Also, an engine output automatic control means 7 is provided together with the external input means 6 or in place of the external display means 6.The engine output automatic control means 7 is configured to control the control target determined by the engine output determination means 5. In order to change the actual engine rotation speed to the engine rotation speed, the actuator is driven by the control signal and the engine rotation speed changing element 8 such as the fuel control rack is actuated and controlled. The engine output automatic control means 7 changes the swash plate angle of the swash plate 9 of the hydraulic pump of the traveling device via an actuator according to a control signal, as necessary, to adjust the vehicle speed. In this way, in the diesel engine output control system of your invention, after determining the engine speed that is the control target, the operator can perform manual operation (semi-automatic) by looking at the display 6. Alternatively, the engine speed changing element 8 may be automatically controlled (fully automatic control) by the engine output automatic control means 7.Furthermore, based on this, various types of diesel engines may be controlled. A wide range of control and management can be performed by inputting driving information.

[Actual 7jl+! Example] Hereinafter, a preferred embodiment in which the diesel engine output control system according to the invention is applied to a construction machine equipped with a hydrostatic transmission will be described based on the drawings from FIG. 2 onwards. This diesel engine output control system consists of a sensor group S
and a processing unit C that performs various information processing using the data input from the sensor group S and the data input by the external input means K, and the actuator is driven by the control signal output from the information processing unit C. and an external display section for displaying instructions and information to the operator in response to display signals output from the above-mentioned emotion processing Hpc. That is, the sensor group S includes, as shown in FIG.
) are provided in the John 11 and the working device W, respectively. First, the tea cell engine E includes an engine rotation speed sensor SEL that determines the engine rotation speed, a fuel supply amount sensor S1 that measures the amount of fuel supplied to the engine, and a lubricating oil temperature sensor that measures the lubricating oil temperature. A lubricating oil pressure sensor SE4 that measures lubricating oil pressure, an exhaust temperature sensor SE5 that measures engine exhaust temperature, an intake air pressure sensor S F, 6 that measures intake air pressure, and Intake air temperature sensor SIE that measures temperature
7, and a cooling water temperature sensor SE that measures the temperature of the cooling water.
8. Next, Bytroscuit I Transmission 1.
+ includes a 1-live oil pressure sensor SHI that measures the pump drive oil pressure, a swash plate angle sensor S I-12 that measures the pump swash plate angle, and a hydraulic oil temperature sensor S H3 that measures the hydraulic oil temperature. It is equipped with a Spiel Harsenzer (SH4) that measures the speed lever's speed and loaf. Historically, the work equipment W is equipped with a discharge oil pressure sensor - SWI that measures the discharge oil pressure of the work equipment system pump, and a hydraulic oil temperature sensor SW2 that measures the operating/dl temperature. Control lehar sensor SW3 that measures the speed by the operating speed of the j1nt+:+-lehrer and also the position of the illus l-+ coke.
The above-mentioned sen→J' group S (i.e., SEI~8.SH]~4°SW1~3) continuously performs sensync and outputs data to the information processing section C in real time. There is ζ. The information processing unit C to which data from the sensor group S is inputted is comprised of a so-called microcomputer configuration consisting of a ■/○ board CPU, RAM, and ROM, and performs various information processing. That is, in the information processing section C, the load horsepower calculation means CI calculates the pump discharge pressure from the pump drive oil pressure data input from the drive oil pressure sensor SHI, and calculates the pump discharge pressure from the swash plate angle data and engine rotation speed input from the swash plate angle sensor SH2. The pump flow rate (QS (D) cm3/sec
) is calculated, and the pump discharge pressure (P (D)h/c+
++2) and pump flow rate, P (D) (Kg/cm2) XQS (D)
(cm3/sec)750〇1 Calculate the horsepower consumption (HP (D)) of the drive pump, similarly calculate the pump discharge pressure from the data input from the discharge oil pressure sensor SW1, and input it from the engine rotation speed sensor SEI. The pump flow rate (QS (H) cm3/sec) is calculated based on the engine rotation speed data and reduction ratio, and from the pump discharge pressure (P (H) Kg/cm2) and the pump flow rate, 750〇1 working equipment. The horsepower consumption (HP (H)) of the pump is calculated to calculate the horsepower consumption as a load. The engine output HP required for this is calculated by dividing the consumed horsepower by the pump total efficiency, as shown in the following equation. Here, η(D) Total efficiency of the Nidrive pump η(H): Total efficiency of the working equipment pump α: ? Next, the output correction calculation processing means C2 inputs the type (specific gravity) data of the fuel used and the working area altitude (average outside air ""Eft )-5'2"14"
1y-9-5E47613 Arithmetic processing is performed based on input correction element data such as crankcase oil temperature to calculate a correction value for the actual engine output under these operating conditions. Next, the net output calculation processing means C3 calculates each horsepower consumption after the value obtained by the load horsepower calculation means C1 is corrected by the output correction calculation processing means C2 and the net engine output based on the consumption horsepower. It is. Based on the calculated net engine output, the optimum engine speed determining means C4 determines the engine speed at which the fuel efficiency is optimal for the predetermined horsepower consumption while giving priority to the speed of the work equipment. That is, the optimum engine speed determining means C4 includes an engine performance data file stored in a recording means (not shown) provided in the information processing section C and an engine speed determination program. Here, in the engine performance data file, each engine output (HP) and the required engine speed (r, p, m) at full load and partial load of the engine are correlated (for example, as in a fuel consumption curve). The engine performance data shown in parentheses is stored. Therefore, the engine speed at the highest efficiency point (minimum speed) required for a given engine output can be called up. Measuring means C5 and vehicle speed measuring means CIO are provided, and the former working equipment speed measuring means C5 determines how the operator operates the working equipment based on the fluctuation or displacement state of the control lever obtained by the control lever sensor SW3. The latter vehicle speed measuring means C10 measures the speed stage designated by the operator from the cent position of the speed 1' control lever obtained by the speed lever sensor SH4, and uses the data to determine whether the speed is instructed (requested). Based on this, it is determined whether the operator needs force (i.e., the hydraulic pressure of the drive system's hydraulic oil) or speed (i.e., the /R amount of the drive system's hydraulic oil) for the traveling device. Based on such a configuration, when the engine speed determination program stored in the ROM of the information processing section C starts, as shown in FIG. The operator obtains the horsepower consumption data of the equipment (including surplus horsepower, etc., the same shall apply hereinafter), the corrected horsepower consumption data of the traveling equipment (including surplus horsepower, the same shall apply hereinafter), and the working equipment speed measuring means C5. Input the speed data of the working equipment that is being instructed (requested).Next, in step ①, it is determined whether the horsepower consumption data of the working equipment is larger than a preset reference value (minimum work horsepower consumption value), and if it is smaller. If so, in step ■ it is determined whether the horsepower consumption data of the traveling device is larger than a preset reference value (minimum traveling horsepower consumption value). If this is smaller, in step ■ the horsepower consumption data of the traveling device is also set to the reference value. If it is determined that the engine speed is lower than If it is determined that the value is greater than the value, in step (2), the vehicle speed measuring means C5 uses the speed lever sensor S H4 to determine whether the operator requires force (i.e., the hydraulic pressure of the drive system's hydraulic oil) for the traveling gear. Or, determine whether speed (that is, the flow rate of hydraulic oil in the drive system) is required, and if only force is required and the minimum rotation speed for light loads can be used, then this minimum rotation speed for light loads is the optimal engine. determined by the number of rotations. In other cases, especially when the operator requires vehicle speed, the engine speed at the highest efficiency point corresponding to the horsepower consumption data is called up and the optimal (claw-to-claw speed) is determined. If the horsepower consumption data of the working equipment input in step ■ is greater than the preset reference value, step ■
The process then proceeds to step (3), where it is determined whether the horsepower consumption of the traveling device is greater than a preset reference value. If it is determined here that the horsepower consumption of the traveling equipment is smaller than the standard value, in step 2, does the operator instruct (request) the power (i.e., the hydraulic pressure of the hydraulic oil in the working equipment system) for the working equipment? Alternatively, it is determined whether the speed (1417, flow rate of hydraulic oil in the working device system) is being instructed (requested). And when the operator needs the power of the working device, /l! of said working device! The engine speed at the highest efficiency point corresponding to the li cost horsepower data is called, and the engine speed is determined as the optimum engine speed. In addition, if it is determined that the operator is prioritizing the speed of the work equipment in step The engine speed required to increase the speed of the working device is calculated, and the engine speed is determined to be the optimum engine speed. Next, if it is determined that the horsepower consumption of the traveling equipment is larger than the reference value in step Determined by engine speed. It is good if the normally configured hydrostatic transmission can achieve the vehicle speed instructed (requested) by the operator within this determined optimum engine speed range. By displacing (largely changing the angle) the swash plate angle of the swash plate (swash plate) via an actuator such as the swash plate angle controller 5 and increasing the amount of oil discharged to the drive motor, the vehicle speed can be increased without changing the engine speed. It is necessary to change (quickly). Therefore, the above judgment is made in step (2), and if the vehicle speed cannot be achieved, in step (2), the diagonal angle necessary for the vehicle speed is urgently used, and the swash plate angle is controlled together with the engine speed. A control pattern is determined based on the optimal engine speed and swash plate angle determined in this way, and a control signal based on the control pattern causes various actuators to the execution unit to perform a predetermined U1 operation at 11 engine revolutions as described later. The number and swash plate angle are changed to predetermined values -U''.Furthermore, operating information or instructions may be displayed to the operator via a display section based on the above control pattern, and in this case, the above operating information or Alternatively, the operator manually operates the engine according to instructions. The execution section A and the display section may be provided together, or either one of them may be provided. Here, the engine speed determination program The basic idea will be explained in other words based on the formula for calculating the engine output HP. (Principle) HP...Engine output HP (D)...Travelling horsepower consumption HP (H)...Work equipment consumption horsepower α ... Horsepower consumed by auxiliary equipment and surplus horsepower η (D) ... Total efficiency of the drive pump η (H)
...Total efficiency of the working equipment pump In the above explanatory formula, H
Let P maintain the highest efficiency point. (Special cases) However, the following conditions are special cases. i), HP (D)/η(D) and HP (H)/η
(■ If () is less than the preset setting value (hereinafter simply referred to as "setting value"), it is the minimum rotation for light load (or no load). ii), HP (D) / η ( D) is below the set value and HP (H
)/η(H) is greater than the set value, HP(H)/η(H
) + α. 1ii) If HP (D) / η (D> is above the set value and HP (H) / η (H) is below the set value, the engine speed is controlled so that HP is maintained at the maximum efficiency point, The predetermined vehicle speed is obtained by displacing the swash plate angle within the range of the engine speed 4 (the maximum swash plate angle is determined by the speed selector lever position, the same applies hereinafter). iv) , HP (D) / η (D ) and HP (H
)/η(H) are both greater than the set value
5 gives priority to HP (H) / η (H) and HP (H)
/η (I) Control the engine speed according to 10α. A predetermined vehicle speed is then obtained by changing the swash plate angle within the engine speed range. For example, the swash plate angle is displaced within the range of HP-(HP(H)/η(H)+α) to operate at the optimum fuel efficiency point. Incidentally, the swash plate 9 controlled by the actuator of the execution section is the swash plate (2) provided on each of the two variable displacement piston pumps installed in the hydrostatic transmission, as shown in FIG. If the inclination of the swash plate 9 is increased using a hydraulic cylinder 10 shown as an example of a swash plate angle controller, the amount of oil sent to the motor will increase and the running speed will increase (
Figure 4 (see bl). Furthermore, if the inclination of the swash plate 9 is reduced using the hydraulic cylinder 10, the amount of oil sent to the motor will be reduced and the running speed will be slowed down.If the inclination is further reduced to 0 degrees, the discharge amount will be 0 and the vehicle will stop (Fig. 4). (see (a)). If the angle is further to the opposite side, the outlet and inlet of the hydraulic oil will be reversed and the vehicle will run in the opposite direction. The inclination of the swash plate 9 configured in this manner is preset according to the engine speed, but in the present invention, the inclination angle is further changed by means of control means, for example, hydraulic pressure is used to greatly change the inclination of the swash plate. This is achieved by a configuration such as increasing the stroke of the cylinder 10. Next, the fuel consumption rate calculation processing means C6 uses the fuel supply amount sensor S
Fuel consumption is measured by inputting the fuel supply amount data obtained from E2, and a fuel efficiency rate is measured from this fuel consumption data and the consumed horsepower data obtained from the net output calculation processing means C3. The current fuel efficiency rate obtained in this way is the maximum: f
! A display signal may be outputted to the display section by comparing the fuel consumption rate at the highest efficiency point obtained by the i-engine speed determining means C4. In this case, on the display section, there is an operation aid or CR that allows you to visually check whether the current operation is optimal for the fuel yellow rate or not using color-coded lamps (not shown) such as red, yellow, and blue.
If an operation assisting means DI is provided on T (not shown) to represent operations performed by the operator as an image, it is possible to semi-automatically perform the profit J at the highest efficiency point. Further, the intake air pressure data obtained from the intake air pressure sensor SE6 and the intake air temperature data obtained from the intake air temperature sensor SE7 are input to the air-fuel ratio control processing means C7 to measure the air-fuel ratio, and the measured air-fuel ratio is The air-fuel ratio and the optimum air-fuel ratio are compared and displayed on the operation assisting means D1 of the display section in the same way as the fuel efficiency rate, and the operator p I! A display signal is output so that operation can be performed semi-automatically at the optimum air-fuel ratio depending on the operation. Alternatively, a control means may be provided which controls the air fuel ratio controller A4 via an actuator to achieve the optimum air-fuel ratio. Next, the abnormality determining means C8 detects the lubricating oil temperature sensor SE.
3, lubricating oil pressure sensor SE4, and exhaust temperature sensor S
Input the respective data from E5, intake air pressure sensor SE6, intake air temperature sensor SE7, and cooling water temperature sensor SE8 to determine whether there is an abnormality. The display signal is output to the abnormality display means 1]2 which displays the presence or absence of an abnormality or the location of the abnormality. At the same time, a control signal is output to the execution unit,
: Control the controller A1 via the actuator to stop the fuel supply, or control the pump swash plate angle/troller Δ5 via the actuator to set the swash plate angle to 0 and stop running, or Direct emergency stop valve A3 Take appropriate measures in case of an abnormality, such as controlling the entire system and making an emergency stop. Next, the warm idle amplifier processing means C9 inputs data similar to the input data to the abnormality determination means C8 and determines whether or not the operating condition is cold operation, and if it is determined that the operation is cold operation. In this case, a display signal to that effect is output to the operation assisting means DI of the display section, or a control signal is output to the execution section to control the idle adjuster A2 via the actuator to perform idle up for automatic control. . One other external display section displays, for example, the current engine speed, product W-p4 fuel consumption, instantaneous fuel consumption, and cumulative earnings 1 based on the input data from the sensor 1J\S. By displaying the time and other operating information externally on the overnight display means 1) mounted in the cockpit, it becomes a reference material for operator's judgment during operation, and the operation record is kept every time it is recorded by the recording means. I can do it. The configuration of the external display section in this invention is not particularly limited, and in short, it is displayed as information on the situation when the operator operates the traveling equipment and work equipment, or as information on the operator's operation. It may take any form and form of expression that displays instructions or advice. [^] This example describes the case of a construction vehicle equipped with a hydrostatic I/transmission. For example, in the case of a construction vehicle equipped with a power shift transmission equipped with a torque converter, the load on the engine can be measured. use the following means: In other words, since the absorption horsepower of a torque converter is proportional to the cube of the input rotation speed, the transmission sensor group consists of (a) an input rotation speed sensor that measures the input rotation speed (engine rotation speed); l) An output rotation speed sensor that measures the output (drive shaft) rotation speed; and 1. (c) A speed sensor that detects the speed stage of the speed control lever, and (d) a transmission oil temperature sensor that measures the transmission oil temperature from 1 to 1 are provided. Based on the smoothed data, the slip ratio is determined from the difference between the input rotational speed data and the output rotational speed data, and based on that, the load horsepower is determined from the performance curve of the I.ruk':1 engine. 2. If the slip rate exceeds the specified range, 1'J
Since the slip horsepower increases, the speed stage of the transmission is changed from IJJ to eliminate the horsepower loss, or in that case, a speed stage switching control signal is output depending on whether the slip ratio exceeds a predetermined range above or below. Therefore, by controlling the efficiency of the engine and the efficiency of the torque converter so that they can be used within the maximum efficiency range, it is possible to control the engine output so that the fuel efficiency reaches the maximum efficiency point.

【Effect of the invention】

Since this invention is constructed as described above, the engine output can be continuously performed at the highest efficiency point in terms of fuel efficiency, and the highest efficiency point is frequently used, resulting in extremely excellent fuel efficiency. Fuel efficiency can be achieved. In addition, when determining the engine output, it is possible to carry out effective work by giving priority to the speed of the working device, and the vehicle speed can be satisfied within that range by changing the swash plate angle, etc., which is extremely beneficial. .

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of the diesel engine output control system according to the present invention, FIG. 2 is a flowchart showing the engine speed determination procedure, FIG. 3 is a system block diagram, and FIG.
Figures (a) and (b) are diagrams showing the operating state of the swash plate that controls the vehicle speed in the present invention. 1... Running load measuring means 2... Working load measuring means 3... Working equipment speed detecting means 4... Optimum engine speed calculating means 5... Engine output determining means 6... External display means 7... Engine output automatic control means 8... Engine speed changing element 9... Swash plate Fig. 3

Claims (2)

[Claims] (1) A system for controlling the output of a diesel engine that drives a hydraulic pump installed in each of the traveling equipment and the working equipment, and a traveling load measuring means for measuring the load (horsepower consumption) of the traveling equipment; Work load measurement means for measuring the load (horsepower consumption); Work equipment speed detection means for detecting the speed of the work equipment requested by the operator from the state of the control lever of the work equipment; and In case of full load or partial load of the diesel engine. It has data on each maximum efficiency point of the fuel efficiency rate, and calculates the engine rotation speed at the maximum efficiency point of the fuel efficiency rate during each work or driving by inputting correction data such as the specific gravity of the fuel used and the temperature of the work place. Based on the data obtained from the running load measuring means, the working load measuring means, and the working equipment speed detecting means, if the working load data exceeds a set value, the speed of the working equipment is The required engine output or engine speed is determined, and if it is determined by the work equipment speed detection means that the operator does not request the speed of the work equipment, the engine output is determined at the maximum efficiency point calculated by the maximum efficiency revolution speed calculation means. an engine output determining means that determines the engine rotation speed; an external display means that externally displays the result of the engine output determining means or an instruction based thereon; and/or a control signal based on the result of the engine output determining means via an actuator. A diesel engine output control system comprising an automatic engine output control means for controlling engine output. (2) When the engine output determination means determines the engine output corresponding to the speed data of the working equipment, the engine output automatic control means controls the engine output and also controls the engine output according to the position of the speed control lever of the traveling equipment as requested by the operator. The vehicle speed is controlled by changing the swash plate angle of a swash plate provided on the hydraulic pump of the traveling device via an actuator based on vehicle speed data obtained from a vehicle speed detection means that detects the vehicle speed. The diesel engine output control system according to claim 1