JP7208602B2 - hybrid system - Google Patents

Description

The present invention relates to a hybrid system mounted on industrial machines.

For example, in a hybrid system mounted on a hybrid vehicle, a control unit (ECU: Electronic Control Unit) calculates a required torque as the hybrid system in order to determine an operation mode of the hybrid system. Operation modes of the hybrid system include, for example, torque split operation, torque assist operation, and regeneration operation.

The torque splitting operation is an operation of dividing the torque of the engine and the torque of the motor generator to bring the charging rate of the battery closer to the target value. The torque assist operation is an operation in which the motor generator assists the torque of the engine. Regenerative operation is an operation in which fuel injection of the engine is stopped and the battery is charged by the motor generator.

Patent Literature 1 discloses a hybrid vehicle that includes a hybrid system having a motor-generator connected to a battery and an engine, and control means for controlling the hybrid system. In the hybrid vehicle described in Patent Document 1, the control means is calculated from the measured values of a rotation sensor that measures the engine speed of the engine and an accelerator opening sensor that measures the opening of the accelerator in the hybrid vehicle. An increase rate of fuel consumption with respect to output torque of the engine is obtained based on the required torque to the engine and preset map data. Then, when the maximum value of the rate of increase in fuel consumption exceeds a preset threshold value, the control means causes the engine assist by the motor generator to reach the maximum value of the motor generator in the measured value of the temperature sensor. Perform control starting with allowable drive output.

For example, in an automobile hybrid system as disclosed in Patent Document 1, not only the engine required torque based on accelerator pedal input (in other words, accelerator opening), but also the required torque for each component such as a transmission and an air conditioner. , the required torque for the hybrid system is calculated. In order to calculate the required torque for such a hybrid system, each ECU provided for each component calculates the required torque for each component.

However, in industrial machines such as construction machines, agricultural machines, lawn mowers, generators, compressors, pumps, etc., the configuration of the accelerator varies from application to application. For example, there are models of industrial machines that do not have an accelerator pedal. For industrial machines that do not have an accelerator pedal, the operator uses a dial switch called a hand accelerator instead of the accelerator pedal to indicate a constant engine speed in order to work at a constant engine speed. . In addition, in industrial machines, it is relatively rare that components other than the engine have an ECU, and the required torque of components other than the engine is relatively often unknown. In this way, in a hybrid system installed in an industrial machine, compared with a hybrid system installed in an automobile, it is possible to calculate the required torque as a hybrid system and use it to determine the operation mode of the hybrid system. The problem is that the available input factors are limited.

JP 2016-107669 A

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a hybrid vehicle that can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited. The purpose is to provide a system.

The problem is a hybrid system mounted on an industrial machine, which includes a rotation sensor that detects the engine speed, an accelerator opening sensor that detects the accelerator opening, and a constant speed for the engine. At least one of a rotation speed instruction unit that transmits an instructing rotation speed signal, and a control unit that controls the operation of the engine, wherein the control unit detects the accelerator opening detected by the accelerator opening sensor and the , the rotation speed signal transmitted by the rotation speed indicator, and calculating a torque determining factor for determining a system required torque as a hybrid system based on at least one of; The system required torque and the engine required torque for the engine are calculated based on the rotational speed and the calculated torque determinant, and an operation mode is determined based on the relationship between the system required torque and the engine required torque. It is solved by the hybrid system according to the present invention characterized by executing control to

According to the hybrid system according to the present invention, the control unit operates as a hybrid system based on at least one of the accelerator opening detected by the accelerator opening sensor and the rotation speed signal transmitted by the rotation speed instruction unit. Calculate the torque determinant for determining the system demand torque of That is, the control unit can also calculate the torque determinant based on the accelerator opening detected by the accelerator opening sensor, and can also calculate the torque determinant, which is transmitted by the rotation speed instruction unit and instructs the engine to rotate at a certain rotation speed. The torque determinant can be calculated based on the number signal, or the torque determinant can be calculated based on both the accelerator opening and the rpm signal. Then, the control unit calculates the system required torque as a hybrid system and the engine required torque for the engine based on the engine speed detected by the rotation sensor and the calculated torque determinant, and calculates the system required torque and the engine required torque. Control is executed to determine the operation mode based on the relationship with engine demand torque. Therefore, even if the hybrid system is installed in an industrial machine that does not have an accelerator pedal, or if the control unit is not installed in a component other than the engine, the control unit of the present invention , a more appropriate system required torque and an engine required torque can be calculated, and a more appropriate operation mode can be determined based on the relationship between the system required torque and the engine required torque. Thereby, the hybrid system according to the present invention can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

The hybrid system according to the present invention is preferably characterized in that the torque determinant is the fuel injection amount of the engine.

According to the hybrid system according to the present invention, the control unit controls the engine fuel based on at least one of the accelerator opening detected by the accelerator opening sensor and the rotation speed signal transmitted by the rotation speed instruction unit. Calculate the injection amount. Then, the control unit calculates the system required torque as a hybrid system and the engine required torque for the engine based on the engine speed detected by the rotation sensor and the calculated fuel injection amount of the engine, and calculates the system required torque. Control is executed to determine the operation mode based on the relationship between torque and engine demand torque. Therefore, the hybrid system according to the present invention can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

In the hybrid system according to the present invention, preferably, the control unit corrects the calculated fuel injection amount, based on the rotation speed detected by the rotation sensor and the corrected fuel injection amount. and calculating the engine demand torque.

According to the hybrid system according to the present invention, the control unit corrects the fuel injection amount, and calculates the required engine torque based on the engine speed detected by the rotation sensor and the corrected fuel injection amount. . This reduces PM (Particulate Matter) contained in the exhaust gas, making it a more appropriate operating mode in situations where the engine speed drops due to overload or where rapid acceleration responsiveness is required. , the torque assist operation can be executed.

In the hybrid system according to the present invention, preferably, the control unit pre-stores map data indicating the relationship between the rotational speed of the engine, the fuel injection amount, and the torque of the engine. and calculating the system required torque and the engine required torque based on the map data.

According to the hybrid system of the present invention, the control unit calculates the system required torque and the engine required torque based on map data stored in advance. It is possible to calculate more appropriate system required torque and engine required torque while shortening the time.

In the hybrid system according to the present invention, preferably, the control section executes control to determine the operation mode further based on a charging rate of a battery connected to the motor generator.

According to the hybrid system of the present invention, the control unit executes control to determine the operation mode based not only on the relationship between the system required torque and the engine required torque, but also on the state of charge of the battery connected to the motor generator. do. Therefore, the hybrid system according to the present invention can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

In the hybrid system according to the present invention, preferably, the control unit sets the engine request torque to zero when the system request torque is less than a first threshold and the charging rate is less than a second threshold. In addition, a motor required torque for the motor generator is calculated, and a regenerative operation in which the battery is charged by the motor generator is determined as the operation mode.

According to the hybrid system of the present invention, the controller calculates the motor-requested torque for the motor-generator based on the relationship between the system-required torque and the engine-required torque and the charging rate of the battery, and performs regenerative operation as a more appropriate operation mode. can be executed.

In the hybrid system according to the present invention, preferably, when the system required torque is larger than the engine required torque and the charging rate is larger than a second threshold, the system required torque and the engine A motor required torque for the motor generator is calculated based on the difference from the required torque, and a torque assist operation in which the motor generator assists the torque of the engine is determined as the operation mode.

According to the hybrid system of the present invention, the control unit calculates the motor-requested torque for the motor-generator based on the relationship between the system-required torque and the engine-required torque and the charging rate of the battery, and selects a torque assist mode as a more appropriate operation mode. Actions can be performed.

In the hybrid system according to the present invention, preferably, the control unit controls at least one of a case where the system required torque is equal to or less than the engine required torque, and a case where the charging rate is equal to or less than a second threshold. a torque split operation that calculates a motor required torque for the motor generator according to the charging rate, divides the torque of the engine and the torque of the motor generator, and brings the charging rate closer to a target value. It is characterized in that it is determined as the operation mode.

According to the hybrid system of the present invention, the controller calculates the motor-required torque for the motor-generator based on the relationship between the system-required torque and the engine-required torque and the charging rate of the battery. Actions can be performed.

In the hybrid system according to the present invention, preferably, the control unit calculates the system required torque that is larger than the torque generated only by the engine.

According to the hybrid system according to the present invention, the control unit executes the torque assist operation as a more appropriate operation mode even when the engine speed is relatively low, and the torque generated by the engine alone is larger than that generated by the engine. System required torque can be generated. As a result, it is possible to reduce the amount of exhaust gas of the engine and reduce the particulate matter contained in the exhaust gas, while improving the fuel efficiency.

According to the present invention, it is possible to provide a hybrid system that can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

1 is a block diagram showing a hybrid system according to a first embodiment of the invention; FIG. It is a block diagram showing a hybrid system according to a second embodiment of the present invention. 1 is a block diagram showing the main configuration of a hybrid system according to an embodiment; FIG. 4 is a flow chart showing an overview of the operation of the hybrid system according to the embodiment; 4 is a flow chart showing a specific example of the operation of the hybrid system according to the embodiment; 4 is a flow chart showing a specific example of the operation of the hybrid system according to the embodiment; It is a table which illustrates the map data of this embodiment. It is a graph showing a torque curve of the hybrid system according to the present embodiment.

Preferred embodiments of the invention are described in detail below with reference to the drawings.
Since the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are applied. Unless otherwise stated, the invention is not limited to these modes. Further, in each drawing, the same constituent elements are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a block diagram showing a hybrid system according to a first embodiment of the invention.
A hybrid system 2A according to this embodiment is mounted on industrial machines such as construction machines, agricultural machines, lawn mowers, generators, compressors, and pumps. As shown in FIG. 1, the industrial machine on which the hybrid system 2A according to the present embodiment is mounted has an accelerator pedal 65, and the speed of the engine 3 is variable by the accelerator pedal. The hybrid system 2</b>A includes an engine 3 , a motor generator 41 , a battery pack 42 , a DC/DC converter 43 , a controller 5 and an accelerator opening sensor 61 .

The engine 3 is an internal combustion engine such as an industrial diesel engine, an industrial gasoline engine, an industrial gas engine, or the like. The engine 3 is, for example, a multi-cylinder engine such as a supercharged, high-output three-cylinder engine or four-cylinder engine with a turbocharger. As shown in FIG. 1 , the engine 3 has a rotation sensor 31 , a DOC (Diesel Oxidation Catalyst) 32 , and a DPF (Diesel Particulate Filter) 33 . However, the engine 3 is not limited to the configuration shown in FIG. 1, and may be one without a DOC or DPF. Further, the engine 3 is not limited to a common rail, and may have an electronically controlled governor as long as the fuel injection is electronically controlled.

The rotation sensor 31 detects the rotation speed of the engine 3 and transmits a voltage signal related to the rotation speed of the engine 3 to the control unit 5 via a CAN (Controller Area Network) communication line. The control unit 5 converts the received voltage signal related to the rotational speed of the engine 3 into the rotational speed. The power generated by the engine 3 is transmitted to power take-off parts 71 such as hydraulic pumps and transmissions (T/M) of industrial machines.

The motor generator 41 is an AC generator and is connected to the engine 3 via a transmission member 34 such as a V-belt. The motor generator 41 is driven by the power generated by the engine 3 and transmitted through the transmission member 34 to generate electricity. In addition, the motor generator 41 generates a rotational force from the electric power supplied from the battery pack 42 when, for example, the number of revolutions of the engine is reduced due to an overload or when rapid acceleration responsiveness is required. to assist or support the torque of the engine 3 by transmitting torque to the engine 3 via the . Details of this will be described later.

The battery pack 42 is, for example, a lithium ion storage battery, and is electrically connected to the motor generator 41 . The battery pack 42 of this embodiment is an example of the "battery" of the present invention. The battery pack 42 is electrically connected to the motor generator 41 by, for example, a 48V system line, and stores electricity generated by the motor generator 41 . That is, the battery pack 42 is charged by power generated by the motor generator 41 . Also, the battery pack 42 supplies the stored electricity to the motor generator 41 . That is, the battery pack 42 discharges and supplies power to the motor generator 41 when the motor generator 41 requires power.

The DC/DC converter 43 is electrically connected to the battery pack 42 through a high voltage system line such as 48 V or 24 V, and converts the high voltage direct current discharged from the battery pack 42 into a low voltage direct current such as 12 V. do. In addition, the DC/DC converter 43 is electrically connected to the lead battery 72 by, for example, a low-voltage system line. Electricity converted from high-voltage direct current to low-voltage direct current by the DC/DC converter 43 is stored in the lead battery 72 . The electricity stored in the lead battery 72 is supplied to electrical loads 73 such as lights, electric heaters, and wipers of industrial machinery.

As described above, the industrial machine equipped with the hybrid system 2A according to this embodiment has the accelerator pedal 65 . The accelerator opening sensor 61 detects the input of the accelerator pedal 65, that is, the accelerator opening, and transmits a signal regarding the accelerator opening to the control unit 5 via the CAN communication line.

The control unit 5 includes an ECU (Electronic Control Unit or Engine Control Unit) and an HCU (Hybrid Control Unit), and manages the hybrid system 2A. The HCU may be provided integrally with the ECU, or may be provided separately from the ECU.

The control unit 5 acquires various information and receives various signals to perform calculations, generates control signals for controlling the operations of parts such as the engine 3, the motor generator 41 and the battery pack 42, and controls the CAN. It transmits to each part by means of telecommunication lines including. For example, the control unit 5 calculates the fuel injection amount of the engine 3, calculates the target air amount of the engine 3, determines the operation mode of the hybrid system 2A, and determines the control parameters of the engine 3. Then, a control signal is transmitted to each part through an electric communication line to instruct each part to drive.

Operation modes of the hybrid system 2A include, for example, torque split operation, torque assist operation, and regeneration operation. The torque splitting operation is an operation of dividing the torque of the engine 3 and the torque of the motor generator 41 to bring the charging rate of the battery pack 42 closer to the target value. The torque assist operation is an operation in which the motor generator 41 assists or supports the torque of the engine 3 . The regenerative operation is an operation in which the fuel injection of the engine 3 is stopped and the battery pack 42 is charged by the motor generator 41 . Details of the operation modes of the hybrid system 2A will be described later.

FIG. 2 is a block diagram showing a hybrid system according to a second embodiment of the invention.
It should be noted that if the components of the hybrid system 2B according to the second embodiment are the same as the components of the hybrid system 2A according to the first embodiment described above with reference to FIG. , the differences will be mainly described.

A hybrid system 2B according to the present embodiment is installed in industrial machinery such as construction machinery, agricultural machinery, lawn mowers, generators, compressors, and pumps, like the hybrid system 2A described above with reference to FIG. As shown in FIG. 2, the industrial machine equipped with the hybrid system 2B according to the present embodiment has a hand accelerator 62 instead of the accelerator pedal 65, and the rotation speed of the engine 3 is kept constant by the hand accelerator 62. It is a machine that is set.

An operator of an industrial machine equipped with the hybrid system 2B instructs a constant engine speed with the hand accelerator 62 in order to perform work at a constant engine speed. The hand accelerator 62 is, for example, a dial switch, receives a constant rotation speed of the engine 3 input by the operator in response to the operator's operation on the hand accelerator 62, and rotates to instruct the constant rotation speed of the engine 3. A number signal is transmitted to the control unit 5 via the CAN communication line. The hand accelerator 62 of this embodiment is an example of the "rotational speed indicator" of the present invention. It should be noted that the "rpm indicator" of the present invention is not limited to the hand accelerator 62 alone.

Other components are the same as those of the hybrid system 2A according to the first embodiment described above with reference to FIG.

In the following description, for convenience of explanation, the concept including both the hybrid system 2A according to the first embodiment and the hybrid system 2B according to the second embodiment may be referred to as "hybrid system 2". As described with reference to FIGS. 1 and 2, the hybrid system 2 according to the present embodiment may be installed in a model of industrial machine equipped with the accelerator pedal 65, or may be installed in a model not equipped with the accelerator pedal 65 ( In other words, it may be installed in an industrial machine such as a model equipped with a hand accelerator 62). Moreover, the hybrid system 2 according to the present embodiment may be mounted on a model of industrial machine having both the accelerator pedal 65 and the hand accelerator 62 .

Next, the control unit 5 of this embodiment will be further described with reference to the drawings.
FIG. 3 is a block diagram showing the main configuration of the hybrid system according to this embodiment.

The control unit 5 of this embodiment has a calculation unit 51 , a storage unit 52 and a communication unit 53 . The calculation unit 51 reads the program 521 stored in the storage unit 52 and executes various calculations and processes. The storage unit 52 stores (memorizes) a program 521 executed by the calculation unit 51 and map data 522 used when calculating a system required torque and an engine required torque, which will be described later. Details of the map data 522 will be described later. Note that the data stored in the storage unit 52 is not limited to the program 521 and map data 522 . Examples of the storage unit 52 include ROM (Read Only Memory) and RAM (Random Access Memory). Note that the program 521 is not limited to being stored in the storage unit 52, and may be stored in advance in a storage medium readable by the calculation unit 51 and distributed, or downloaded to the control unit 5 via a network. may be Also, the storage unit 52 may be an external storage device connected to the control unit 5 .

The calculation unit 51 includes a fuel injection amount calculation unit 511, a system request torque calculation unit 512, an engine request torque calculation unit 513, a motor request torque calculation unit 514, an operation mode determination unit 515, and an engine control parameter determination unit 516. and have Note that the calculation unit 51 may have a target air amount calculation unit (not shown) instead of the fuel injection amount calculation unit 511 or together with the fuel injection amount calculation unit 511 . A fuel injection amount calculation unit 511, a system request torque calculation unit 512, an engine request torque calculation unit 513, a motor request torque calculation unit 514, an operation mode determination unit 515, an engine control parameter determination unit 516, and a target air amount calculation unit are stored. It is realized by the calculation unit 51 executing the program 521 stored in the unit 52 . Note that the fuel injection amount calculation unit 511, the system request torque calculation unit 512, the engine request torque calculation unit 513, the motor request torque calculation unit 514, the operation mode determination unit 515, the engine control parameter determination unit 516, and the target air amount calculation unit are , may be implemented by hardware, or may be implemented by a combination of hardware and software.

The calculation unit 51 determines the system required torque as the hybrid system 2 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the rotational speed signal transmitted by the hand accelerator 62. Calculate the torque determinant of Torque determinants include the fuel injection amount of the engine 3 and the target air amount of the engine 3 . In other words, the "fuel injection amount" and "target air amount" in this embodiment are examples of the "torque determinant" in the present invention. That is, the calculation unit 51 calculates the fuel injection amount of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the rotation speed signal transmitted by the hand accelerator 62. Alternatively, the target air amount of the engine 3 may be calculated. In the following description, the case where the "torque determinant" is the "fuel injection amount" will be taken as an example.

The fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the rotational speed signal transmitted by the hand accelerator 62. . In other words, the fuel injection amount calculation unit 511 can also calculate the fuel injection amount of the engine 3 based on the accelerator opening detected by the accelerator opening sensor 61, and the rotation speed signal transmitted by the hand accelerator 62 The fuel injection amount of the engine 3 can also be calculated based on this. Alternatively, the fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on both the accelerator opening detected by the accelerator opening sensor 61 and the rotation speed signal transmitted by the hand accelerator 62. can also The fuel injection amount calculation unit 511 also calculates the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 . As described above, the fuel injection amount of the engine 3 of this embodiment is an example of the "torque determinant" of the present invention.

A system required torque calculation unit 512 calculates a system required torque for the hybrid system 2 . Specifically, the system required torque calculation unit 512 calculates the system required torque based on the rotation speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount calculated by the fuel injection amount calculation unit 511. do. For example, the system required torque calculation unit 512 calculates the system required torque based on the map data 522 indicating the relationship between the engine 3 rotation speed, the engine 3 fuel injection amount, and the engine 3 torque. Note that the system request torque calculation unit 512 is not limited to calculating the system request torque based on the map data 522. For example, the rotation speed of the engine 3, the fuel injection amount of the engine 3, and the torque of the engine 3 , the system demand torque may be calculated based on a mathematical expression, graph, or the like showing the relationship between .

An engine required torque calculation unit 513 calculates an engine required torque for the engine 3 . Specifically, the engine request torque calculation unit 513 calculates the engine request torque based on the rotation speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount calculated by the fuel injection amount calculation unit 511. do. For example, the engine required torque calculation unit 513 corrects the fuel injection amount calculated by the fuel injection amount calculation unit 511, and the rotation speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection amount are Based on this, the engine demand torque is calculated. For example, after correcting the fuel injection amount calculated by the fuel injection amount calculation unit 511, the engine required torque calculation unit 513 corrects the rotation speed of the engine 3, the fuel injection amount of the engine 3, the rotation speed of the engine 3, The engine demand torque is calculated based on the map data 522 showing the relationship between . Note that the engine request torque calculation unit 513 is not limited to calculating the engine request torque based on the map data 522. For example, after correcting the fuel injection amount calculated by the fuel injection amount calculation unit 511, the engine 3, the fuel injection amount of the engine 3, and the torque of the engine 3.

A motor request torque calculation unit 514 calculates a motor request torque for the motor generator 41 . Specifically, motor request torque calculation unit 514 calculates the motor request torque based on the operation mode of hybrid system 2 determined by operation mode determination unit 515 . More specifically, the motor required torque calculation unit 514 calculates the system required torque calculated by the system required torque calculation unit 512, the engine required torque calculated by the engine required torque calculation unit 513, and the charging rate of the battery pack 42. (SOC: State Of Charge), and the required motor torque is calculated.

Operation mode determination unit 515 determines the operation mode of hybrid system 2 . That is, operation mode determination unit 515 determines which operation mode of regeneration operation, torque assist operation, and torque split operation is to be executed as the operation mode of hybrid system 2 . Specifically, the operation mode determination unit 515 determines the system required torque calculated by the system required torque calculation unit 512, the engine required torque calculated by the engine required torque calculation unit 513, the charging rate of the battery pack 42, determines the operation mode of the hybrid system 2 based on. Alternatively, the operation mode determining unit 515 determines the system required torque calculated by the system required torque calculating unit 512, the engine required torque calculated by the engine required torque calculating unit 513, the charging rate of the battery pack 42, the rotation sensor 31 The operation mode of the hybrid system 2 is determined based on the rotation speed of the engine 3 detected by and.

The engine control parameter determination unit 516 calculates the fuel injection amount of the engine 3 calculated based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515, and the rotation speed of the engine 3 detected by the rotation sensor 31. , to determine the control parameters of the engine 3 . In other words, engine control parameter determination unit 516 determines the fuel injection amount written back (that is, converted) based on the operation mode of hybrid system 2 determined by operation mode determination unit 515 and the amount detected by rotation sensor 31 . A control parameter for the engine 3 is determined based on the rotational speed of the engine 3 obtained from the engine 3 . Control parameters of the engine 3 include, for example, an injection pattern of the engine 3, an injection timing of the engine 3, and an EGR (Exhaust Gas Recirculation) valve opening.

The communication unit 53 communicates with the engine 3 including the rotation sensor 31, at least one of the accelerator opening sensor 61 and the hand accelerator 62, the motor generator 41, the battery pack 42, and the DC/DC converter 43 through electric communication lines, It transmits and receives various information and various signals.

1 and 2, in construction machinery, agricultural machinery, and industrial machinery such as lawn mowers, generators, compressors, pumps, etc., the configuration of the accelerator varies from application to application. For example, there are models of industrial machines that do not have an accelerator pedal 65 . In a model of industrial machine that does not have an accelerator pedal 65, the operator uses the hand accelerator 62 to indicate a constant engine speed. Further, in industrial machines, components other than the engine 3 are relatively rare to have an ECU, and the required torque of the components other than the engine 3 is relatively often unknown. As described above, in the hybrid system 2 mounted on the industrial machine, the input factors that can be used for calculating the system required torque of the hybrid system 2 are limited compared to the hybrid system mounted on the automobile. ing.

On the other hand, the control unit 5 (specifically, the fuel injection amount calculation unit 511) of the hybrid system 2 according to the present embodiment transmits the accelerator opening detected by the accelerator opening sensor 61 and the hand accelerator 62. The fuel injection amount of the engine 3 is calculated based on at least one of the rotation speed signal received from the engine 3 and the rotation speed signal. Then, the control unit 5 (specifically, the system required torque calculation unit 512) calculates the rotational speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount of the engine 3 calculated by the fuel injection amount calculation unit 511. , the system required torque for the hybrid system 2 is calculated. In addition, the control unit 5 (specifically, the engine demand torque calculation unit 513) is based on the rotation speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount calculated by the fuel injection amount calculation unit 511. to calculate the engine demand torque. For example, the engine required torque calculation unit 513 corrects the fuel injection amount calculated by the fuel injection amount calculation unit 511, and the rotation speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection amount are Based on this, the engine demand torque is calculated.

According to the hybrid system 2 according to the present embodiment, even if the hybrid system 2 is installed in an industrial machine that does not have an accelerator pedal 65, or if the controller 5 is installed in a component other than the engine 3, Even if not, the control unit 5 of the present embodiment can calculate more appropriate system required torque and engine required torque. As a result, the hybrid system 2 according to the present embodiment can calculate more appropriate system required torque and engine required torque while the input factors that can be used when calculating the system required torque are limited. can. Further, the control unit 5 (specifically, the operation mode determination unit 515) can determine a more appropriate operation mode based on the relationship between the system required torque and the engine required torque. Thereby, the hybrid system 2 according to the present embodiment can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

Further, the control unit 5 (specifically, the operation mode determination unit 515) operates based not only on the relationship between the system required torque and the engine required torque, but also on the charging rate of the battery pack 42 connected to the motor generator 41. Determine mode. Therefore, the hybrid system 2 can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

Next, the operation of the hybrid system according to this embodiment will be described with reference to the drawings.
FIG. 4 is a flow chart showing an overview of the operation of the hybrid system according to this embodiment.

First, in step S11, the fuel injection amount calculation unit 511 calculates the engine 3 speed based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the rotation speed signal transmitted by the hand accelerator 62. Calculate the fuel injection amount. The fuel injection amount calculated in step S11 is used to avoid excessive emissions of particulate matter (PM) contained in the exhaust gas and to prevent the output of the engine 3 from exceeding a limit value. This is the fuel injection amount before correction for Then, the system required torque calculation unit 512 calculates the rotation speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount calculated by the fuel injection amount calculation unit 511 (that is, the fuel injection amount before correction). to calculate the system required torque.

Subsequently, in step S12, the engine demand torque calculation unit 513 avoids excessive emission of particulate matter contained in the exhaust gas, and avoids the output of the engine 3 from exceeding the limit value. Therefore, the fuel injection amount calculated by the fuel injection amount calculation unit 511 is corrected, and the maximum fuel injection amount is finally determined. Then, the engine required torque calculation unit 513 calculates the engine required torque based on the rotation speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection amount.

Subsequently, in step S13, the operation mode determining unit 515 determines the hybrid system 2 based on the system required torque calculated by the system required torque calculating unit 512 and the engine required torque calculated by the engine required torque calculating unit 513. operation mode (regenerative operation, torque assist operation, torque split operation). Alternatively, the operation mode determining unit 515 determines the system required torque calculated by the system required torque calculating unit 512, the engine required torque calculated by the engine required torque calculating unit 513, and the rotation of the engine 3 detected by the rotation sensor 31. and the operating mode of the hybrid system 2 is determined based on the number. In addition, operation mode determining unit 515 adjusts the charging rate of battery pack 42 by determining the operating mode of hybrid system 2 further based on the charging rate (SOC) of battery pack 42 . For example, the calculation and processing in step S13 are performed by the HCU.

Subsequently, in step S<b>14 , the fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 . That is, the fuel injection amount calculation unit 511 writes back (that is, converts) the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 .

Further, in step S<b>15 , the motor request torque calculation unit 514 calculates the motor request torque based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 . Then, the control unit 5 transmits a signal regarding the motor demand torque calculated by the motor demand torque calculation unit 514 to the motor generator 41 and instructs the motor generator 41 .

Subsequently, in step S16, the engine control parameter determination unit 516 determines the engine speed based on the fuel injection amount written back by the fuel injection amount calculation unit 511 and the rotation speed of the engine 3 detected by the rotation sensor 31. 3 control parameters are determined.

Subsequently, in step S17, the control unit 5 transmits a signal regarding the control parameter determined by the engine control parameter determination unit 516, and instructs each device to drive.

According to the hybrid system 2 according to the present embodiment, the control unit 5 corrects the fuel injection amount calculated by the fuel injection amount calculation unit 511, the rotation speed of the engine 3 detected by the rotation sensor 31, and the corrected and the required engine torque. As a result, it is possible to reduce the particulate matter contained in the exhaust gas, and to perform the torque assist operation, for example, in situations where the rotation speed of the engine 3 is reduced due to overload or in situations where rapid acceleration responsiveness is required. can.

5 and 6 are flow charts showing a specific example of the operation of the hybrid system according to this embodiment.
FIG. 7 is a table illustrating map data of this embodiment.

As shown in FIG. 5, first, in step S21, the control unit 5 determines whether or not the hybrid system 2 has an error. If the error occurs in the hybrid system 2 (step S21: YES), the controller 5 terminates the operation of the hybrid system 2 .

If the error does not occur in the hybrid system 2 (step S21: NO), in step S23, the fuel injection amount calculation unit 511 determines the accelerator opening detected by the accelerator opening sensor 61 and the The fuel injection amount of the engine 3 is calculated based on at least one of the rotation speed signal obtained from the engine 3 and the engine speed signal. Then, the system required torque calculation unit 512 calculates the rotation speed of the engine 3 detected by the rotation sensor 31 and the fuel injection amount calculated by the fuel injection amount calculation unit 511 (that is, the fuel injection amount before correction). to calculate the system required torque. Further, the engine required torque calculation unit 513 corrects the fuel injection amount calculated by the fuel injection amount calculation unit 511, and the rotation speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection amount are Based on this, the engine demand torque is calculated. The "fuel injection amount before correction" and the "fuel injection amount after correction" are as described above with reference to FIG. The control unit 5 of this embodiment calculates the system required torque and the engine required torque based on the map data 522 pre-stored in the storage unit 52 .

That is, for example, the map data 522 shown in FIG. 7 is stored (stored) in the storage unit 52 . In the map data 522 illustrated in FIG. 7 , the horizontal axis represents the rotation speed of the engine 3 and the vertical axis represents the fuel injection amount of the engine 3 . Further, in the map data 522 illustrated in FIG. 7 , the portion where the horizontal axis (engine speed) and the vertical axis (fuel injection amount) intersect with each other represents the torque of the engine 3 . In other words, the map data 522 illustrated in FIG. 7 indicates the relationship between the rotation speed of the engine 3 , the fuel injection amount of the engine 3 , and the torque of the engine 3 .

On the horizontal axis, the relatively right side is the side where the rotation speed of the engine 3 is relatively high, and the relatively left side is the side where the rotation speed of the engine 3 is relatively low. On the vertical axis, the relatively lower side is the side where the fuel injection amount of the engine 3 is relatively large, and the relatively upper side is the side where the fuel injection amount of the engine 3 is relatively small.

In the description of the present embodiment, as shown in FIG. 7, the fuel injection amount calculation unit 511 calculates the accelerator opening detected by the accelerator opening sensor 61 and the rotational speed signal transmitted by the hand accelerator 62. A case where the fuel injection amount Q8 of the engine 3 is calculated based on at least one of them will be taken as an example. The fuel injection amount Q8 is an example of "the fuel injection amount before correction". Further, in the description of the present embodiment, as shown in FIG. 7, the rotation sensor 31 detects the rotation speed R3 of the engine 3 as an example.

In this case, the system required torque calculation unit 512 calculates the system required torque T38 based on the rotational speed R3 of the engine 3 and the pre-correction fuel injection amount Q8. Subsequently, the engine demand torque calculation unit 513 calculates fuel The fuel injection amount Q8 calculated by the injection amount calculator 511 is corrected, and the maximum fuel injection amount Q5 is finally determined. The fuel injection amount Q5 is an example of the "corrected fuel injection amount". Subsequently, the engine required torque calculation unit 513 calculates the engine required torque T35 based on the rotational speed R3 of the engine 3 and the corrected fuel injection amount Q5. Thus, the control unit 5 of the present embodiment calculates the system required torque T38 and the engine required torque T35 based on the map data 522 pre-stored in the storage unit 52 .

As shown in FIG. 5, in step S24 following step S23, the control unit 5 determines whether the system required torque T38 is smaller than the threshold Th1 and the charging rate of the battery pack 42 is smaller than the threshold Th2. to decide. The threshold Th1 of this embodiment is an example of the "first threshold" of the present invention. The threshold Th2 of this embodiment is an example of the "second threshold" of the present invention.

In step S24, when all the conditions of "system demand torque T38<threshold Th1" and "state of charge of battery pack 42<threshold Th2" are satisfied (step S24: YES), in step S25, the operation mode determination unit 515 determines the regenerative operation as the operation mode of the hybrid system 2 and executes the regenerative operation.

For example, when an industrial machine equipped with the hybrid system 2 descends a slope with the accelerator off, all the conditions of "system demand torque T38<threshold Th1" and "charging rate of battery pack 42<threshold Th2" are satisfied. In such a case, the operation mode determining unit 515 determines the regenerative operation as the operation mode of the hybrid system 2 in step S25.

Then, in step S25, the fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (regenerative operation in step S25). Specifically, the fuel injection amount calculator 511 sets the fuel injection amount of the engine 3 to zero. In other words, engine request torque calculation unit 513 sets the engine request torque to zero. Further, in step S25, the motor request torque calculation unit 514 calculates the motor request torque based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (regenerative operation in step S25). Specifically, the motor request torque calculation unit 514 calculates the motor request torque for charging the battery pack 42 by the motor generator 41 . That is, motor request torque calculation unit 514 sets the motor request torque to zero.

On the other hand, in step S24, if at least one of the conditions of "system demand torque T38<threshold Th1" and "state of charge of battery pack 42<threshold Th2" is not satisfied (step S24: NO), in step S31 , the control unit 5 determines whether the system required torque T38 is greater than the engine required torque T35 and the charging rate of the battery pack 42 is greater than the threshold value Th2.

In step S31, if all the conditions of "system demand torque T38>engine demand torque T35" and "state of charge of battery pack 42>threshold value Th2" are satisfied (step S31: YES), in step S32, the operation mode Determination unit 515 determines the torque assist operation as the operation mode of hybrid system 2 and executes the torque assist operation.

For example, when an industrial machine equipped with the hybrid system 2 climbs a slope, the number of rotations of the engine 3 decreases due to an overload, or when rapid acceleration responsiveness is required. T35” and “charging rate of battery pack 42>threshold Th2” are satisfied, operation mode determination unit 515 determines the torque assist operation as the operation mode of hybrid system 2 in step S32.

Then, in step S32, the fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (torque assist operation in step S32). Further, in step S32, the motor request torque calculation unit 514 calculates the motor request torque based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (torque assist operation in step S32). Specifically, motor request torque calculation unit 514 calculates the motor request torque based on the difference between system request torque T38 and engine request torque T35. That is, the motor request torque calculation unit 514 calculates the motor request torque for the motor generator 41 to assist the torque of the engine 3 . Thereby, the hybrid system 2 can improve the work performed by the industrial machine on which the hybrid system 2 is mounted.

On the other hand, in step S31, if at least one of the conditions of "system required torque T38>engine required torque T35" and "state of charge of battery pack 42>threshold value Th2" is not satisfied, in other words, "system required torque T38≦ If at least one of the conditions of "engine required torque T35" and "state of charge of battery pack 42≦threshold value Th2" is satisfied (step S31: NO), operation mode determination unit 515 determines that hybrid system 2 determines the torque split operation as the operation mode of , and executes the torque split operation.

For example, when an industrial machine equipped with the hybrid system 2 runs on flat ground, at least one of the conditions of "system required torque T38>engine required torque T35" and "charging rate of battery pack 42>threshold value Th2" is met. If the conditions are not satisfied, the operation mode determination unit 515 determines the torque split operation as the operation mode of the hybrid system 2 in step S33.

Then, in step S33, the fuel injection amount calculation unit 511 calculates the fuel injection amount of the engine 3 based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (torque split operation in step S33). Further, in step S33, the motor request torque calculation unit 514 calculates the motor request torque based on the operation mode of the hybrid system 2 determined by the operation mode determination unit 515 (torque split operation in step S33).

Specifically, for example, a case where the system required torque is 100 N·m and the engine 3 can generate a torque of 150 N·m will be taken as an example. In this case, for example, the fuel injection amount calculator 511 calculates the fuel injection amount for causing the engine 3 to generate a torque of 100 N·m. Alternatively, the fuel injection amount calculation unit 511 sets the fuel injection amount of the engine 3 to zero, and the motor request torque calculation unit 514 sets the motor generator 41 to assist the engine 3 with a torque of 100 N·m. Calculate the motor required torque. Alternatively, for example, the fuel injection amount calculation unit 511 calculates the fuel injection amount for generating a torque of 50 N·m in the engine 3 , and the motor request torque calculation unit 514 calculates the torque required by the motor generator 41 to the engine 3 at 50 N·m. · Calculate the motor required torque for assisting the torque of m. Alternatively, for example, the fuel injection amount calculation unit 511 calculates the fuel injection amount for generating a torque of 130 N·m in the engine 3, and the motor required torque calculation unit 514 causes the motor generator 41 to charge the battery pack 42. An extra torque of 30 N·m of the engine 3 is calculated as the motor required torque for the above operation.

Thus, when at least one of the conditions of "system required torque T38>engine required torque T35" and "state of charge of battery pack 42>threshold value Th2" is not satisfied (step S31: NO), the control unit 5 , the torque of the engine 3 and the torque of the motor generator 41 can be distributed to bring the charging rate of the battery pack 42 closer to the target value.

Following steps S25, S32 and S33, the control unit 5 terminates the operation of the hybrid system 2.

5 to 7, the control unit 5 corrects the fuel injection amount Q8 calculated by the fuel injection amount calculation unit 511, and the corrected fuel injection amount Q5, the engine demand torque T35 is calculated. As a result, it is possible to reduce the particulate matter contained in the exhaust gas, and to perform the torque assist operation, for example, in situations where the rotation speed of the engine 3 is reduced due to overload or in situations where rapid acceleration responsiveness is required. can.

Further, control unit 5 calculates system required torque T38 and engine required torque T35 based on map data 522 pre-stored in storage unit 52 . Therefore, control unit 5 can calculate more appropriate system required torque T38 and engine required torque T35 while shortening the processing time for calculating system required torque T38 and engine required torque T35.

Further, control unit 5 determines the operation mode based not only on the relationship between system required torque T38 and engine required torque T35 but also on the charging rate of battery pack 42 connected to motor generator 41 . Therefore, the control unit 5 can determine a more appropriate operation mode while the input factors that can be used when determining the operation mode are limited.

FIG. 8 is a graph showing a torque curve of the hybrid system according to this embodiment.
The horizontal axis of the graph shown in FIG. 8 represents the rotation speed of the engine 3 . The vertical axis of the graph shown in FIG. 8 represents the torque of the engine 3 .

As shown in FIG. 8 , the control unit 5 (specifically, the system demand torque calculation unit 512) of the present embodiment calculates a torque greater than the torque generated only by the engine 3 in the entire range of the rotation speed of the engine 3. Calculate the required torque. That is, the control unit 5 causes the motor generator 41 to assist or support the torque of the engine 3 in order to generate torque in a range that cannot be generated by the engine 3 alone in the entire range of the engine 3 speed. Execute control. In other words, the control unit 5 does not perform control for the motor generator 41 to assist or support the torque of the engine 3 in the torque region that can be generated by the engine 3 alone.

Therefore, even when the rotation speed of the engine 3 is relatively low, the control unit 5 executes the torque assist operation as a more appropriate operation mode, and generates a system required torque larger than the torque generated only by the engine 3. can be made As a result, it is possible to suppress the displacement of the engine 3 and reduce the particulate matter contained in the exhaust gas, while improving the fuel efficiency.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. Some of the configurations of the above embodiments may be omitted, or may be arbitrarily combined in a manner different from the above.
As described above with reference to FIG. 3, the calculation unit 51 may calculate the target air amount as a torque determinant for determining the system required torque. In this case, the calculation unit 51 calculates the target air amount of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the rotation speed signal transmitted by the hand accelerator 62. calculate. Then, the calculation unit 51 calculates the system required torque as the hybrid system 2 based on the rotation speed of the engine 3 detected by the rotation sensor 31 and the calculated target air amount of the engine 3 . This provides similar effects to those described above with respect to the embodiments of the present invention.

2, 2A, 2B: Hybrid system 3: Engine 5: Control unit 31: Rotation sensor 32: DOC 33: DPF 34: Transmission member 41: Motor generator 42: Battery pack 43: DC/ DC converter 51: computing unit 52: storage unit 53: communication unit 61: accelerator opening sensor 62: hand accelerator 65: accelerator pedal 71: power extraction part 72: lead battery 73: 12V load 511: Fuel injection amount calculation unit 512: System request torque calculation unit 513: Engine request torque calculation unit 514: Motor request torque calculation unit 515: Operation mode determination unit 516: Engine control parameter determination unit 521: Program 522: Map data Q5, Q8: Fuel injection amount R3: Rotational speed T35: Engine required torque T38: System required torque Th1, Th2: Threshold

Claims (7)

A hybrid system mounted on an industrial machine,
a rotation sensor that detects the number of revolutions of the engine;
at least one of an accelerator opening sensor that detects the accelerator opening and a rotation speed indicator that transmits a rotation speed signal that indicates a constant rotation speed to the engine;
a control unit that controls the operation of the engine;
with
The control unit determines a system required torque as a hybrid system based on at least one of the accelerator opening detected by the accelerator opening sensor and the rotation speed signal transmitted by the rotation speed indicating unit. calculating the first fuel injection amount for determination, calculating the system required torque based on the rotational speed detected by the rotation sensor and the first fuel injection amount , and calculating the first fuel injection amount is corrected, and the maximum fuel injection amount for avoiding the output of the engine from exceeding the limit value at the rotation speed detected by the rotation sensor is determined as the second fuel injection amount, and the maximum fuel injection amount detected by the rotation sensor is determined. an engine required torque for the engine is calculated based on the rotational speed and the second fuel injection amount, and a relationship between the system required torque and the engine required torque and a charging rate of a battery connected to the motor generator are calculated ; determining an operation mode based on the operation mode, and executing control for calculating a fuel injection amount of the engine based on the operation mode . The control unit determines a control parameter of the engine based on the fuel injection amount of the engine calculated based on the operation mode and the rotation speed detected by the rotation sensor. The hybrid system according to claim 1. The control unit pre-stores map data indicating the relationship between the rotational speed of the engine, the fuel injection amount, and the torque of the engine, and controls the system required torque based on the pre-stored map data. 3. The hybrid system according to claim 1 or 2 , wherein the engine request torque and the engine demand torque are calculated. When the system required torque is smaller than a first threshold and the charging rate is smaller than a second threshold, the control unit sets the engine required torque to zero and calculates a motor required torque for the motor generator. 4. The hybrid system according to any one of claims 1 to 3, wherein a regenerative operation in which the battery is charged by the motor generator is determined as the operation mode. When the system required torque is greater than the engine required torque and the charging rate is greater than a second threshold, the control unit controls the motor generator based on the difference between the system required torque and the engine required torque. 4. The hybrid system according to any one of claims 1 to 3, wherein a torque assist operation in which the motor generator assists the torque of the engine is determined as the operation mode. . When the system required torque is equal to or less than the engine required torque, or when the charging rate is equal to or less than a second threshold value, the control unit controls the motor A torque split operation in which a motor required torque for a generator is calculated, and the engine torque and the motor generator torque are distributed to bring the charging rate closer to a target value is determined as the operation mode. A hybrid system according to any one of claims 1 to 3 . The hybrid system according to any one of claims 1 to 6 , wherein the control section calculates the system required torque that is larger than the torque generated only by the engine.

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