JP2005098216A - Engine output control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine output control device capable of dramatically improving fuel economy. <P>SOLUTION: A total load computing means 33 calculates operating loads of a hydraulic motor, an air conditioner, and F and R hydraulic pumps, varying from hour to hour, based on detection signals from oil pressure sensors 17 to 19, on/off signals from a switch 20 or the like, and calculates a total load from each of the operating loads. An output setting means 34 selects gross output curves G1, G2, G3 etc. so as to attaining minimum required gross output in accordance with the total load. Therefore, since the total load is calculated by precisely calculating operating loads of not only the hydraulic motor for a cooling fan but also a plurality of load devices, when the total load is small, the gross output can be securely suppressed all the time. In addition, an output reduction rate can be increased, and fuel economy can be dramatically improved by making output reduction time longer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine output control device.

Conventionally, in a diesel engine used for construction machinery, etc., when an auxiliary machine such as a fan for cooling an engine or a fan for cooling a hydraulic system is fully operated and a plurality of work machines are driven simultaneously. In addition, in the state close to the maximum operating load, the net output necessary to drive the work machine is insufficient for the full operation of the auxiliary machine, resulting in insufficient power and hindering workability. is there.
Therefore, when the working load of the work implement is large and it is not necessary to cool the engine or hydraulic system so much, the fan is not always operated at full speed, but is temporarily stopped, or at a low speed. It has been proposed that the surplus output generated by the operation is compensated for driving the work machine, and thus the work machine is driven at a higher output (for example, Patent Document 1).

However, according to the technique described in Patent Document 1, since the engine is always driven along the maximum gloss output curve, the cooling fan cools the engine more than necessary when the working load on the work machine is small. Or when the operating load on the cooling fan is small (low rotation or when it is stopped), the work equipment will be driven with more output than necessary, and the fuel consumption rate (g / PSh) The problem that becomes worse occurs.
Therefore, in recent years, where improvement in fuel efficiency is eagerly desired, attention is paid to the operating load due to the engine cooling fan, and the net output minus the amount of this operating load is kept constant as the output for driving the work implement, while the gross output is increased. Control which adjusts according to the operating condition of a cooling fan is proposed (nonpatent literature 1).

  According to this proposal, it is sufficient to increase the gloss output at a high operating load that rotates the cooling fan at a high speed, and to suppress the gross output at a low operating load that rotates at a low speed. There is nothing. Further, since the net output for driving the work machine is also maintained constant, it is not driven with an output more than necessary. As a result, fuel efficiency is improved.

JP 2001-3385 A Construction Machinery 2003, 6, Vol.39, No.6, pages 13-16 (issued on June 1, 2003)

  However, since the technique according to Non-Patent Document 1 adjusts the gross output only for the operating state of the engine cooling fan, it cannot sufficiently cope with construction machines and other vehicles equipped with many auxiliary machines. There are limits to improving fuel economy.

  The objective of this invention is providing the engine output control apparatus which can improve a fuel consumption significantly.

  An engine output control device according to claim 1 of the present invention includes a load detection unit that detects an operating load of at least two or more load devices being driven by an engine, and each load device based on a detection result by the load detection unit. Total load calculation means for obtaining a total load every predetermined time, and output setting means for setting the gross output of the engine in accordance with the total load.

  The engine output control device according to claim 2 is the engine output control device according to claim 1, wherein the load device includes a vehicle moving device, a cooling fan driving hydraulic motor, a steering driving device, a work implement driving device, an alternator, It is any two or more of the air conditioners.

  An engine output control apparatus according to a third aspect is the engine output control apparatus according to the first aspect, wherein the load device is a cooling fan driving hydraulic motor and a work machine driving power source.

  An engine output control device according to a fourth aspect is the engine output control device according to the first aspect, wherein the load device is a cooling fan driving hydraulic motor and an engine direct-coupled power source.

  According to the first aspect of the present invention, the total load calculating means of the control means calculates the operating loads of a plurality of load devices that change from moment to moment based on the detection results of the load detecting means, and calculates the total from the operating loads. Calculate the load. Then, the output setting means sets the gloss output curve so that the minimum required gross output corresponding to the total load is obtained. Therefore, by precisely calculating the operating load in the load device, it is possible to always suppress the gross output when the total load is small, the output reduction rate is large, the output reduction time is long, and the fuel consumption is increased. Is greatly improved.

  According to the invention of claim 2, two or more load devices are selected from the vehicle moving device, the cooling fan driving hydraulic motor, the steering driving device, the work machine driving device, the alternator, and the air conditioner according to the specifications of the vehicle and the like. What is necessary is just to select, for example, the fuel consumption of various vehicles, such as a hydraulic shovel, a bulldozer, and a wheel loader, can be improved reliably.

  According to the invention of claim 3, since the working load of the power source for driving the work machine is also taken into consideration, the output reduction control of the gross output according to the work mode including the working load of the auxiliary machine such as a fan can be performed. Dense and reliable fuel economy improvement.

According to the invention of claim 4, since the operating load of the engine direct-coupled power source is also taken into consideration, the output reduction control of the gross output is carried out for a larger operating load including the fan driving load, which is sufficient. Can improve fuel efficiency.
Here, the engine power source directly connected to the engine does not include the power source for driving the work machine according to claim 3, and is other than the transmission, the generator (the large one unlike the battery charging alternator), and the work machine driving Hydraulic pumps used in

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic diagram showing a hydraulic excavator 1 equipped with a controller (engine output control device) 30 according to a first embodiment of the present invention.
The hydraulic excavator 1 drives and discharges a front hydraulic pump (a power source for driving a work machine, a load device) 3 and a rear hydraulic pump (a power source for driving a work machine, a load device) 4 with the output of a diesel engine 2. The hydraulic oil pressure is switched by the operation valve 5 to drive the bucket cylinder 6, arm cylinder 7, boom cylinder 8, swing motor 9, and travel motor 10.

At this time, the engine 2 includes a fuel injection device 11 including a fuel injection pump, a governor, and the like. The fuel injection device 11 performs fuel injection of the controller 30 based on a throttle signal from the fuel dial 12. It is controlled by the quantity control means 31 (FIG. 2).
The swash plate angle of the F (front) hydraulic pump 3 and the R (rear) hydraulic pump 4 is variable by the control valves 3A and 4A, and each control valve 3A and 4A has a governor set rotation speed by the fuel dial 12. Based on the actual engine speed detected by the rotation sensor 2A, control is performed by the pump control means 32 (FIG. 2) of the controller 30 so that the pumps 3 and 4 absorb the matching torque at each output point of the engine 2. Is done.

Further, in the hydraulic excavator 1 according to the present embodiment, a PTO (Power Take-Off: power take-off device) 13 is connected to the output shaft of the engine 2, and the cooling fan 14 for cooling the engine 2 and the air conditioner are connected via the PTO 13. (Air conditioner, load device) 15 is operated.
In the cooling fan 14, the hydraulic pump 16 is driven by the PTO 13, and the hydraulic motor (load device) 14A is driven by the hydraulic pressure from the hydraulic pump 16 to rotate the fan. The rotational speed of the hydraulic motor 14A is variable and is controlled by the controller 30 in accordance with the temperature of the engine coolant.
Furthermore, in this embodiment, in addition to the hydraulic pressure at the hydraulic pump 16, the hydraulic pressure at the Menin F and R hydraulic pumps 3 and 4 is detected by the hydraulic sensors (load detection means) 17, 18, and 19, and the detection signal is sent to the controller. 30. An on / off signal is input to the controller 30 from a switch (load detection means) 20 provided in the air conditioner 15.

The controller 30 will be described in detail below based on the block diagram of FIG.
In addition to the fuel injection amount control means 31 for controlling the fuel injection device 11 and the pump control means 32 for controlling the control valves 3A and 4A, the controller 30 is based on the throttle signal from the fuel dial 12, and in this embodiment. As a unique configuration, a total load calculating means 33 and an output setting means 34 are provided. These means 31 to 34 are computer programs stored in the storage means 35, and are called and executed when the engine switch is on.

  First, a plurality of gross output curves G1, G2, G3... And a net output curve N shown in FIG. 3 are stored in the storage means 35, and the total load of the load device and correspondingly selected. Gloss output curves G1, G2, G3... Are stored as a table 35A (FIG. 2).

  The gross output curves G1, G2, G3... Are automatically turned off according to fluctuations in the operating load of the hydraulic motor 14A and the air conditioner 15 as auxiliary machines, and fluctuations in the operating load of the main F and R hydraulic pumps 3 and 4. It is an output curve that changes. The net output curve N is an output curve that is maintained to drive only the F and R hydraulic pumps 3 and 4 in a normal use situation of the hydraulic excavator 1, that is, the bucket cylinder 6, the arm cylinder 7, the boom cylinder 8, and the turning This is an output curve that is maintained to drive the work machine drive device such as the motor 9 and the traveling motor 10 so as not to run out of power.

  The output curve of the present embodiment is stored as an engine torque curve in which the horizontal axis represents the engine speed and the vertical axis represents the engine torque, but the vertical axis may be the engine output (kW, PS).

  The total load calculation means 33 calculates the operating loads of the hydraulic motors 14A, F, R hydraulic pumps 3 and 4, and the air conditioner 15 every elapse of a predetermined time. That is, detection signals from the respective hydraulic sensors 17 to 19, torque control signals to the control valves 3A and 4A generated by the swash plate angle, that is, the pump control means 32 in the F and R hydraulic pumps 3 and 4, air conditioners 15, each operating load is calculated based on an on / off signal from the switch 20 (the operating load when the air conditioner 15 is on is known). Then, the total load calculation means 33 calculates the total load applied to the engine 2 by summing up these operating loads.

  The output setting means 34 determines the operation status of the work implement driving devices 6 to 9 from the operation load of the F and R hydraulic pumps 3 and 4 in particular, and determines in which work mode the work is being performed. Further, the output setting means 34 refers to the table 35A and selects the gloss output curves G1, G2, G3... So that the minimum output corresponding to the total load is obtained. The fuel injection amount control means 31 controls the fuel injection amount along the gloss output curves G1, G2, G3... Selected here, and the pump control means 32 is the swash plate of the F and R hydraulic pumps 3 and 43. Control the corners.

In the present embodiment as described above, the selection of each gloss output curve G1, G2, G3... Is not particularly limited, but is performed based on the following conditions, for example.
G1: The output setting means 34 determines that the work mode is a heavy work mode such as heavy excavation, and determines that the cooling fan 14 is operating based on a detection signal from the pressure sensor 14A. When it is determined that the air conditioner 15 is also operating based on the ON / OFF signal from the switch 20.
G2: When the heavy work mode is determined and only the cooling fan 14 is operating. Or, it is determined that the normal work mode is selected, such as normal excavation work, leveling work, work using a breaker, and the cooling fan 14 and the air conditioner 15 are both operating.

G3: When it is determined that the operation mode is normal, and one of the cooling fan 14 and the air conditioner 15 is operating.
G4: When it is determined that the operation mode is the same as when traveling and both the cooling fan 14 and the air conditioner 15 are operating.
G5: When the normal operation mode is determined and both the cooling fan 14 and the air conditioner 15 are stopped or in low operation. Or, it is determined that the operation mode is fine, and one of the cooling fan 14 and the air conditioner 15 is operating.
G6: When it is determined that the operation mode is fine, and both the cooling fan 14 and the air conditioner 15 are stopped or not operating.

According to this embodiment, there are the following effects.
(1) That is, the total load calculating means 33 of the controller 30 detects the operating load of the hydraulic motor 14A, the air conditioner 15, and the F and R hydraulic pumps 3 and 4 that change from moment to moment from detection signals from the hydraulic sensors 17 to 19. The calculation is performed based on the on / off signal from the switch 20, and the total load is calculated from each operating load. Then, the output setting means 34 selects the gloss output curves G1, G2, G3... So that the minimum required gross output corresponding to the total load is obtained. Accordingly, not only the hydraulic motor 14A for the cooling fan 14 but also the operating loads in the plurality of load devices 3, 4, 14, and 15 are precisely calculated to calculate the total load, so that the total load is small. It is always possible to reliably suppress the gross output, and the output reduction rate can be increased, and the fuel consumption can be greatly improved by extending the output reduction time.

(2) Further, by taking into consideration the operating load of the F and R hydraulic pumps 3 and 4 that are the power source for driving the work machine, the output setting means 34 starts from the operating load to the heavy work mode, the normal work mode, and the fine operation mode. Therefore, the output reduction control of the gross output corresponding to each work mode can be realized, and the fuel consumption can be improved more precisely and surely.

(3) Furthermore, in the situation where the output required for actual work machine driving may be smaller than the preset net output, such as when working with a small operation load such as the fine operation mode, the difference is used. However, the hydraulic motor 14A or the air conditioner 15 can be driven, and the gloss output can be further lowered (in the case of the fine operation mode with the gloss output curve G5). In the fine operation mode, when both the cooling fan 14 and the air conditioner 15 are stopped (gross output curve G6), it is possible to realize economy control as if the net output curve N itself is lowered, further promoting fuel consumption reduction. it can.

(4) In the medium- and large-sized hydraulic excavators 1 equipped with the cab, since the air conditioner 15 is frequently turned on and off during work in summer, the output reduction control is performed in consideration of the operating load of the air conditioner 15. As a result, it is possible to achieve a reduction in fuel consumption that is more in line with the usage status of the hydraulic excavator 1.

[Second Embodiment]
FIG. 4 shows a second embodiment of the present invention. In FIG. 4, the same reference numerals are assigned to the same components as those in the first embodiment. Hereinafter, a configuration different from the first embodiment will be described.

  In the present embodiment, the hydraulic motor 14A of the cooling fan 14 is not driven by the hydraulic pressure from the hydraulic pump connected to the PTO, but is driven by the hydraulic pressure supplied via the operation valve 5. Moreover, although it does not describe about an air-conditioner, it can provide suitably. On the hydraulic inlet side of the bucket cylinder 6, arm cylinder 7, boom cylinder 8, swing motor 9 as a work machine drive device (load device) and travel motor 10 as a vehicle moving device (load device), a hydraulic sensor ( Load detection means) 36 to 40 are provided. Other configurations including the controller 30 are substantially the same as those in the first embodiment.

  In the present embodiment, detection signals from the hydraulic sensors 36 to 40 are input to the total load calculating means 33 described in FIG. 2 of the first embodiment. Then, the total load calculating means 33 calculates the working load for each of the work implement driving devices 6 to 9 and the traveling motor 10 based on the detection signal, and sums them to calculate the total load. According to the present embodiment as described above, the effects (1) to (3) described above can be obtained and the following effects can be obtained.

(5) In this embodiment, since the working loads for each of the work machine driving devices 6 to 9 and the travel motor 10 are calculated, the work content can be further subdivided and recognized from this result. That is, in the first embodiment, normal excavation work, leveling work, work using a breaker, and the like are collectively recognized as the normal work mode, but the operation of the work machine drive devices 6 to 9 in each work is performed. Due to subtle differences in load, these tasks can be easily identified. As a result, the normal work mode can be further divided into excavation mode, correction mode, and breaker mode, and by preparing a gloss output curve corresponding to each mode, more precise output control is possible. This can be realized and further fuel consumption reduction can be promoted.

[Third Embodiment]
FIG. 5 is a schematic diagram showing a schematic configuration of a bulldozer 50 equipped with a controller (engine output control device) 30 according to the first embodiment of the present invention. In FIG. 5 as well, the same components as those in the first embodiment described above are denoted by the same reference numerals. Detailed description here is omitted for similar configurations.

The bulldozer 50 is configured to directly drive a transmission (engine directly connected power source, load device) 51 with the output of the diesel engine 2 and to drive a sprocket 54 via a steering clutch 52 and a final drive 53.
The PTO 13 connected to the output shaft of the engine 2 is used to drive a main hydraulic pump (working machine drive power source, load device) 55 and a hydraulic motor (load device) 14A for the cooling fan 14. A hydraulic pump 16 is connected. The hydraulic pressure from the hydraulic pump 55 is distributed by the operation valve 5 and is distributed to the R (right) tilt cylinder 56, the L (left) tilt cylinder 57, the R (right) lift cylinder 58, and the L (left) lift cylinder 59. .

The control valve 55A of the hydraulic pump 55 is controlled by the pump control means 32 (FIG. 2) of the controller 30 as in the first and second embodiments. In the bulldozer 50, an engine throttle opening signal from a throttle lever or dexel pedal (not shown) is input to the fuel injection amount control means 31 (FIG. 2) of the controller 30.
On the other hand, a hydraulic pressure sensor (load detection means) 60 is provided on the discharge side of the hydraulic pump 55, and an arbitrary load detector (load detection means) 61 including a strain sensor, a torque meter and the like is provided on the torque input side of the transmission 51. The detection signals from these are input to the total load calculation means 33 (FIG. 2) of the controller 30. The same applies to the hydraulic sensor 17.

Therefore, in this embodiment, the total load calculating means 33 calculates the operating loads of a plurality of load devices such as the hydraulic motor 14A, the transmission 51, and the hydraulic pump 55, and sums them to calculate the total load. The output setting means 34 selects the gloss output curves G1, G2, G3... According to the total load.
At this time, typical work modes determined based on differences in operating loads of the hydraulic pump 55 and the transmission 51 include an excavation mode, a soil pushing mode, a hill climbing mode, and the like.
In order to improve the accuracy of recognition of each work mode, the height of the blade, the shift position of the speed stage, the forward / backward movement position of the mono lever, the position of the throttle lever, the position of the dexel pedal, etc. may be considered.

According to this embodiment, although there is a difference in configuration between the excavator 1 and the bulldozer 50, the effects (1) to (3) described above can be obtained in the same manner by the similar configuration. In addition, there are the following effects.
(6) In the bulldozer 50, most of the work is performed while traveling forward, and the fluctuation of the operating load of the transmission 51 is very large. Therefore, calculating the operating load of the transmission 51 step by step to obtain the total load and selecting the gross output curves G1, G2, G3... Based on the total load can more reliably promote fuel consumption reduction in the bulldozer 50. There is an effect.

In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention.
For example, in each of the above embodiments, the hydraulic motor 14A of the cooling fan 14 and the air conditioner 15 have been described as load devices classified as auxiliary machines. However, in addition, the steering drive device, the alternator, and the hydraulic motor for driving the oil cooling fan are described. Or any auxiliary machine mounted on a construction machine or other vehicle. For example, by selecting a plurality of load devices according to a hydraulic excavator, a bulldozer, a wheel loader, etc., and performing output reduction control based on the total load of each load device, it is possible to reliably improve the fuel efficiency of various vehicles. .

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of quantity, other details, and the like.
Therefore, the description limited to the shape, quantity and the like disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

  The present invention includes construction machines such as hydraulic excavators, bulldozers, motor graders, wheel loaders, industrial machines such as engine driven stationary generators, stationary crushers, stationary soil conditioners, dump trucks, self-propelled It is suitably used for industrial vehicles such as a type crusher and a self-propelled soil improvement machine.

1 is a schematic diagram showing a hydraulic excavator equipped with an engine output control device according to a first embodiment of the present invention. The block diagram which shows the said output control apparatus. Diagram showing output curve The schematic diagram which shows the hydraulic shovel carrying the engine output control apparatus which concerns on 2nd Embodiment of this invention. The schematic diagram which shows the hydraulic shovel carrying the engine output control apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Engine, 3 ... Front hydraulic pump (power source for working machine drive, load device), 4 ... Rear hydraulic pump (power source for work machine driving, load device), 6 ... Bucket cylinder (work machine drive device, load device) ), 7... Arm cylinder (work machine drive device, load device), 8... Boom cylinder (work machine drive device, load device), 9 .. Turning motor (work machine drive device, load device), 10. Moving device, load device), 14A ... Hydraulic motor (load device), 15 ... Air conditioner (air conditioner, load device), 17 ... Hydraulic sensor (load detection means), 18 ... Hydraulic sensor (load detection means), 19 ... Hydraulic pressure Sensor (load detection means), 20 ... switch (load detection means), 30 ... controller (engine output control device), 33 ... total load calculation means, 34 ... output setting means, 36 ... hydraulic sensor ( Load detection means), 37 ... Hydraulic sensor (load detection means), 38 ... Hydraulic sensor (load detection means), 40 ... Hydraulic sensor (load detection means), 51 ... Transmission (directly connected power source, load device), 55 ... Hydraulic pump (working machine drive power source, load device), 60 ... hydraulic sensor (load detection means), 61 ... load detector (load detection means).

Claims (4)

In the engine output control device,
Load detection means (17-20, 36-40,) for detecting the operating load of at least two or more load devices (3,4, 6-10, 14A, 15, 51, 55) being driven by the engine (2) 60, 61)
Based on the detection result by the load detection means (17-20, 36-40, 60, 61), the total load for each predetermined time of each load device (3,4,6-10,14A, 15,51) is obtained. Total load calculating means (33);
The engine output control device (30), further comprising output setting means (34) for setting a gross output of the engine (2) according to the total load. The engine output control device (30) according to claim 1,
The load device is any two of a vehicle moving device (10), a cooling fan driving hydraulic motor (14A), a steering driving device, a work machine driving device (6-9), an alternator, and an air conditioner (15). This is the engine output control device (30). The engine output control device (30) according to claim 1,
The load device is a cooling fan driving hydraulic motor (14A) and a work machine driving power source (3, 4, 55). The engine output control device (30). The engine output control device (30) according to claim 1,
The load device is a cooling fan driving hydraulic motor (14A) and an engine direct-coupled power source (51). The engine output control device (30).

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