JP4159489B2 - Torque control device for hydraulic pump of construction machinery - Google Patents

Description

  The present invention relates to a torque control device for a hydraulic pump of a construction machine such as a hydraulic excavator, and is particularly used in a diesel engine equipped as a power source of a construction machine and a drive source of a hydraulic pump for operating an actuator. The present invention relates to a torque control device for a hydraulic pump of a construction machine that can set an optimum hydraulic pump torque according to a fuel rank.

  Conventionally, there are light oil / kerosene / heavy oil, etc. as fuels that can be used for diesel engines of construction machinery. Also, the rank changes greatly depending on the storage state, and some of them contain a lot of moisture and dust. These are already known to have various adverse effects on the engine, such as a decrease in output, deterioration in smoke, or durability.

It is also known that in order to extract the optimum torque of a hydraulic pump in a construction machine, it is necessary to consider the environmental situation of the construction machine and control the torque of the hydraulic pump according to the environmental situation. In connection with this, a method for estimating the environmental situation by signals from sensors attached to the construction machine main body and the diesel engine and controlling the torque of the hydraulic pump has already been proposed (for example, (See Patent Document 1).
Japanese Patent No. 3383754.

  The invention described in Patent Document 1 is a method for estimating the environmental situation based on signals from sensors attached to the construction machine main body and the diesel engine, and controlling the torque of the hydraulic pump, which depends on the property (rank) of the fuel. The effect is not taken into account. For this reason, this method does not always reach the optimum hydraulic pump torque.

  Therefore, a technical problem to be solved in order to be able to always extract the optimum hydraulic pump torque arises, and the present invention aims to solve this problem.

  In order to solve the above-mentioned problems, the present applicant has conducted research, and in order to derive the optimum hydraulic pump torque, considering the properties of the fuel that actually drives the engine, the applicant has installed it in the hydraulic pump. The conclusion was reached that the solenoid control valve should be controlled. At the same time, the fuel property (rank) is automatically determined, and a method of controlling the torque of the hydraulic pump based on the determination result is also studied.The fuel property is easily determined, and the result is used as a basis. A method for controlling the hydraulic pump torque was found.

The invention according to claim 1 is proposed in order to achieve the above object, and includes a diesel engine equipped as a power source for construction machinery and a drive source for a hydraulic pump for operating an actuator, and torque of the hydraulic pump. A fuel rank determining means for determining a rank of fuel used in the engine, and controlling the control valve in accordance with the fuel rank determined by the fuel rank determining means. A hydraulic pump torque setting device for a construction machine comprising: a hydraulic pump torque setting means, wherein the fuel rank determination means has a plurality of patterns for the work contents and environmental conditions in which the construction machine is operating. The fuel rank identification map is formed by classifying and determining the fuel rank from the classification in the work content and the classification in the environmental condition. The signals from the sensors attached to the diesel engine are divided into a classification according to the work content and a classification according to the environmental conditions, and each obtained signal is associated with the fuel rank identification map of the fuel rank identification map. A torque control device for a hydraulic pump of a construction machine, characterized in that the fuel rank is determined .

According to this configuration, based on the hydraulic pump torque setting means to the fuel rank, performs control of the control valve for setting the hydraulic pump torque commensurate with the fuel rank, automatically exits lead to optimal hydraulic pump torque Sutoki The signals from the sensors attached to the construction machine body and the diesel engine are divided into a classification according to the work contents in which the construction machine is operating and a classification according to the environmental conditions in which the construction machine is used. The fuel rank is determined by narrowing down the corresponding signals in correspondence with the fuel rank identification map.

According to a second aspect of the present invention, in the construction of the construction machine according to the first aspect, in the fuel rank determination processing by the fuel rank determination means, monitoring is performed at a set time and the result is updated. A torque control device for a hydraulic pump is provided.

  According to this configuration, the fuel rank is always ascertained by performing monitoring at certain intervals in the current usage state.

According to the first aspect of the present invention, the hydraulic pump torque setting means determines the fuel rank based on the signal from the fuel rank determination means, and controls the control valve corresponding to the fuel rank, and this control matches the fuel rank. and to perform the setting of the hydraulic pump torque, and, automatically derived by construction the torque control of the construction machine hydraulic pump to be able to set an optimum hydraulic pump torque corresponding to the fuel rank you are using In the apparatus, the rank of the fuel can be easily determined by narrowing down the signals from the sensors attached to the construction machine main body and the diesel engine in correspondence with the fuel rank identification map.

In the invention described in claim 2, since the fuel rank is obtained by monitoring at regular intervals, in addition to the effect of the invention described in claim 1, when the fuel used is changed in the middle The control valve control is automatically reviewed, and the optimum hydraulic pump torque is always obtained.

In order to achieve the purpose of always extracting the optimum hydraulic pump torque, a diesel engine equipped as a power source for construction machinery and a drive source for the hydraulic pump for actuator operation, and a control valve for controlling the torque of the hydraulic pump And a fuel rank determination means for determining a rank of fuel used in the engine, and a hydraulic pump torque setting for controlling the control valve according to the fuel rank determined by the fuel rank determination means A torque control device for a hydraulic pump of a construction machine comprising:
The fuel rank determining means classifies work contents and environmental conditions in which the construction machine is operating into a plurality of patterns, and determines a fuel rank from the classification according to the work contents and the classification under the environmental conditions. The fuel rank identification map divides signals from the main body of the construction machine and sensors attached to the diesel engine into a classification according to the work content and a classification according to the environmental conditions, and each obtained signal is classified into the fuel. The present invention is realized by providing a torque control device for a hydraulic pump of a construction machine, wherein the rank of the fuel is determined in correspondence with the fuel rank identification map of the rank identification map.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that items related to the present invention will be described at the same time. FIG. 1 shows a hydraulic excavator as a construction machine to which the present invention is applied. In the hydraulic excavator 10, an upper swing body 13 is rotatably mounted on a lower traveling body 11 via a swing mechanism 12. The upper swing body 13 is provided with a cab 14 on one front side thereof, and a boom 15 is attached to the front center portion so as to be able to be raised and lowered. An arm 16 is attached to the tip of the boom 15 so as to be rotatable up and down, and a bucket 17 is attached to the tip of the arm 16.

  FIG. 2 is a configuration block diagram of an engine control system applied to the excavator 10 of FIG. In FIG. 2, the engine control system of the present embodiment includes an engine 21 for driving the hydraulic excavator 10, a hydraulic pump 22 connected to the power line of the engine 21, an engine controller 23, and a fuel state calculator. 24, each main body device 25, a fuel rank identification map 43, a hydraulic pump torque setting device 44, and a solenoid control valve 45.

  The engine 21 is a diesel engine provided with a fuel injection device 21a, and the hydraulic excavator 10 travels using the engine 21 as a power source.

  The engine 21 is provided with a sensor for detecting the environment of the engine 21 and a sensor for detecting work. Examples of sensors that detect environmental conditions include an atmospheric pressure sensor 26, an intake air temperature sensor 27, a supply air temperature sensor 28, and a supply air pressure sensor 29, and each sensor signal is output to the engine controller 23. Examples of sensors that detect work content include a fuel temperature sensor 30, a fuel intake pressure sensor 31, a cooling water temperature sensor 32, an exhaust temperature sensor 33, a fuel injection pressure sensor 34, and an engine speed sensor 35. A signal is output to the engine controller 23.

  The engine controller 23 functions as a control calculation unit incorporating a microcomputer (commonly referred to as “microcomputer”), and a load factor detector 36 that detects the load factor of the engine 21 based on signals from the sensors 26 to 35. The fuel injection amount command value 37 is generated by fusing the load factor signal from the load factor detector 36 and the signals from the sensors 26 to 35, and the fuel injection command value 37 is sent to the fuel injection device 21a. The control is performed so that the rotational speed of the engine 21 becomes the target engine rotational speed. Further, the sensor signals of the sensors 26 to 35 input to the engine controller 23, the addition rate signal generated by the load factor detector 36, and the fuel injection amount command value 37 are output to the fuel state calculator 24. Is done.

  The hydraulic pump 22 drives an actuator (not shown) including hydraulic cylinders for operating the boom 15, the arm 16, and the bucket 17, and operates by receiving the driving force of the engine 21. The hydraulic pump 22 is provided with a solenoid control valve 45 for adjusting the hydraulic pump torque of the hydraulic pump 22. Further, the hydraulic pump 22 is provided with a hydraulic oil temperature sensor 38 that detects the temperature of the hydraulic oil of the hydraulic pump 22 and a hydraulic pump discharge pressure sensor 39 that detects the discharge pressure of the hydraulic oil from the hydraulic pump 22. Is output to the fuel condition calculator 24.

  Each main body device 25 is a device group including an air cleaner, a fuel supply system line for transporting fuel to the fuel injection device 21a, and various instruments. Each main body device 25 is provided with a fuel remaining amount sensor 40 for detecting the remaining amount of fuel in a fuel tank (not shown) and an atmospheric temperature sensor 41 for detecting the atmospheric temperature. Output to the fuel condition calculator 24.

  Further, each device 25 is provided with an engine operating time detector 42. The engine operating time detector 42 detects the actual operating time of the engine 21 and outputs a detection signal to the fuel state calculator 24.

The fuel state calculator 24 as a fuel rank determining means is configured as a control calculation unit with a built-in microcomputer, and various signals (sensors 26 to 36) from the sensors loaded on the engine 21, that is, the engine controller 23. Are used for the current engine 21 based on the various sensor signals, the signal from the load factor detector 36 and the fuel injection amount command value 37) and various signals from the hydraulic pump 22 (sensor signals of the sensors 38 and 39). The function of identifying the rank of the fuel that has been identified is output, and the result of the identified fuel rank is output to the hydraulic pump torque setting unit 44. In the present embodiment, fuel rank identification by the fuel condition calculator 24 is prepared in advance corresponding to a fuel rank identification map 43 described later and 81 patterns of the fuel rank identification map 43, respectively. The data 81-1, 43-2,..., 43-81 are used. In the data 43-1, 43-2, ..., 43-81, the engine speed frequency and the engine load factor frequency set for each state such as the type of fuel and the degree of contamination are registered in advance.

  The hydraulic pump torque setting unit 44 as the hydraulic pump torque setting means controls the solenoid control valve 45 according to the fuel rank identified and determined by the fuel state calculator 24, and obtains the optimum hydraulic pump torque of the hydraulic pump 22. The hydraulic pump torque is automatically changed.

  FIG. 3 shows an example of the fuel rank identification map 43. The fuel rank identification map 43 classifies work contents in columns in a tree structure, classifies environmental conditions in rows in the same tree structure, and forms a matrix with the classification items in the columns and rows, The numerical values are distributed as fuel patterns at the intersections with the classification content on the horizontal axis.

  That is, in the tree structure in the column, the fuel pump is classified into three items of low / medium / high according to the hydraulic pump discharge pressure, and further, the fuel temperature when the hydraulic pump discharge pressure is low is divided into three items of low / medium / high, The fuel temperature when the pump discharge pressure is medium is classified into three items of low / medium / high, and the fuel temperature when the pump discharge pressure is high is classified into three items of low / medium / high. On the other hand, the tree structure in the row is classified into three items of low / medium / high according to the size of atmospheric pressure, and the outside air temperature when atmospheric pressure is low is divided into three items of low / medium / high, atmospheric pressure. Is classified into three items of low / medium / high, and the fuel temperature when atmospheric pressure is high is classified into three items of low / medium / high. Therefore, in the fuel rank identification map 43, a matrix is formed by the work contents classified in the vertical column and the environmental conditions classified in the horizontal row, and the numerical values are sequentially distributed to the intersections of the fuel rank identification map 43. The usage situation is divided into 81 patterns. The 81 pieces of data 43-1, 43-2,..., 43-81 are distributed so as to correspond to the 81 patterns one by one.

To explain a more specific example,
(1) If the hydraulic pump discharge pressure is classified as “high” and the fuel temperature is classified as “low” in the work content, and the atmospheric pressure is classified as “low” and the outside air temperature is classified as “low” in the environmental content, The classification condition and the environmental classification condition cross at a location of “1”, and therefore the data pattern that matches the current usage status is “1”. Then, in the subsequent operation of determining the fuel rank, the data 43-1 corresponding to the pattern “1” is extracted, and the engine speed frequency for each state registered in the data 43-1 The rank of the fuel currently used is determined by comparing the engine load factor frequency with the engine speed frequency and the engine load factor frequency in the current use situation.
(2) If the hydraulic pump discharge pressure is classified as “medium” and the fuel temperature is classified as “medium” in the work content, and the atmospheric pressure is classified as “medium” and the outside air temperature is classified as “medium” in the environmental content, The classification condition and the environmental classification condition cross at the location “41”, and therefore the pattern representing the usage status is determined as “41”. In the subsequent work of determining the fuel rank, data 43-41 corresponding to the pattern “41” is extracted, and the engine speed frequency for each state registered in the data 43-41, The rank of the fuel currently used is determined by comparing the engine load factor frequency with the engine speed frequency and the engine load factor frequency in the current use situation. (3) If the hydraulic pump discharge pressure is classified as “low” and the fuel temperature is classified as “high” in the work content, and the atmospheric pressure is classified as “high” and the outside air temperature is classified as “high” in the environmental content, The classification condition and the environmental classification condition cross at the location “81”, and therefore the pattern indicating the usage status is “81”. In the subsequent operation of determining the fuel rank, the data 43-81 corresponding to the pattern “81” is extracted, and the engine speed frequency set for each state registered in the data 43-81 is extracted. The rank of the currently used fuel is determined by comparing the engine load factor frequency with the engine speed frequency and the engine load factor frequency in the current use state. In addition to this, the fuel rank can be determined in the same manner.

  Here, the fuel rank determination procedure in the engine control system is pre-programmed in the fuel state calculator 24 shown in FIG. The control procedure of the fuel state calculator 24 in this control system will be described with reference to the flowchart shown in FIG.

First, the state of the construction machine, that is, the clogging of the air cleaner, the clogging of the fuel line, the astringency of the turbine, the damage of each device, etc. is grasped (step S1), and there is no problem in the machine state (good) ) Enters the actual rank determination process shown in and after step S2, and there is a problem (
If it is defective, the process is stopped.

  In the rank determination process, the signals of the sensors 26 to 35 and 38 to 41 are read, and the classification process (step S2) based on the work content corresponding to the fuel rank identification map 43 from the signals of the sensors and the classification process under environmental conditions (Step S3) is performed. Also, the items classified here are made to correspond to the fuel rank identification map 43 respectively, and one pattern representing the current use situation among the 81 patterns of the fuel rank identification map 43 and one corresponding to the pattern. Data (43-1, 43-2, ..., 43-81) are extracted (step S4).

  Subsequently, the engine speed frequency and the engine load factor frequency registered in one extracted data (43-1, 43-2,..., 43-81) and the engine speed frequency in the current use state And the engine load factor frequency are compared (step S5), and the rank of the currently used fuel is determined from the comparison result (step S6). This result is input to the hydraulic pump torque setter 44, which controls the solenoid control valve 45 and sets the hydraulic pump torque corresponding to the fuel rank (step S7). Further, this rank determination process is monitored at regular intervals, and the result is updated. As a result, the latest fuel rank is grasped, and the hydraulic pump torque setter 44 also performs update control on the solenoid control valve 45.

  Therefore, according to the torque control device for the hydraulic pump of the construction machine according to the present embodiment, the hydraulic pump torque setting unit 44 determines the fuel rank based on the signal from the fuel state calculator 24, and the hydraulic pressure corresponding to the fuel rank. Since the solenoid control valve 45 for setting the pump torque is controlled, the optimum hydraulic pump torque corresponding to the fuel rank in use can be automatically derived.

  In addition, the determination of the fuel rank by the fuel state calculator 24 is simple by narrowing down the state by associating signals from sensors attached to the construction machine main body and the diesel engine 21 with the fuel rank identification map 43, and Can be determined automatically.

  Furthermore, the fuel rank identification process is also monitored at regular intervals, so if the fuel used is changed during the process, control of the control valve is automatically reviewed and the optimum hydraulic pump torque is always maintained. can get.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified one.

The figure shows an embodiment of the present invention.
1 is an overall configuration diagram of a hydraulic excavator to which a torque control device according to the present invention is applied. The schematic structure block diagram which shows the structure of the engine control system of a hydraulic excavator same as the above. The figure which shows an example of the fuel rank identification map used with the torque control apparatus of this invention. The flowchart which shows an example of the fuel rank identification procedure in the torque control apparatus of this invention.

Explanation of symbols

21 Engine 22 Hydraulic pump 23 Engine controller 24 Fuel condition calculator (fuel rank setting means)
43 Fuel rank identification map 44 Hydraulic pump torque setting device (hydraulic pump torque setting means)
45 Solenoid control valve

Claims (2)

A diesel engine equipped as a power source for construction machinery and a drive source for a hydraulic pump for operating an actuator , and a control valve for controlling the torque of the hydraulic pump , and a rank of fuel used in the engine fuel rank determining means for determining a torque control system for a hydraulic pump for a construction machine comprising a hydraulic pump torque setting means for controlling said control valve in response to the fuel rank determined by the fuel rank determination means In
The fuel rank determining means classifies work contents and environmental conditions in which the construction machine is operating into a plurality of patterns, and determines a fuel rank from the classification according to the work contents and the classification under the environmental conditions. The fuel rank identification map divides signals from the main body of the construction machine and sensors attached to the diesel engine into a classification according to the work content and a classification according to the environmental conditions, and each obtained signal is classified into the fuel. A torque control device for a hydraulic pump of a construction machine, wherein the rank of the fuel is determined in correspondence with the fuel rank identification map of the rank identification map . 2. The torque control device for a hydraulic pump of a construction machine according to claim 1, wherein the fuel rank determination processing by the fuel rank determination means is monitored every set time and the result is updated .

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