Hybrid system

Abstract

The present invention provides a hybrid power system capable of calculating more appropriate required torques when the input factors available for calculating various required torques are limited. The hybrid power system (2) includes at least one of: a rotation sensor (31) for detecting the rotational speed of an engine (3); an accelerator opening sensor (61) for detecting the accelerator opening degree; and a speed indicator (62) for sending a speed signal indicating a constant rotational speed to the engine (3); and a control unit (5) for controlling the operation of the engine (3). The control unit (5) calculates a torque determination factor for determining the system required torque of the hybrid power system (2) based on at least one of the accelerator opening degree detected by the accelerator opening sensor (61) and the speed signal sent by the speed indicator (62), and performs control to calculate the system required torque based on the rotational speed detected by the rotation sensor (31) and the calculated torque determination factor.

Description

Technical Field

[0001] This invention relates to a hybrid power system mounted on industrial machinery. Background Technology

[0002] For example, in a hybrid system installed in a hybrid vehicle, the control unit (ECU: Electronic Control Unit) calculates the required torque for the hybrid system to determine its operating mode. Examples of hybrid system operating modes include torque splitting, torque assist, and regenerative braking.

[0003] Torque distribution is the process of distributing engine torque and motor generator torque to bring the battery charge rate close to the target value. Torque assist is the process of the motor generator providing torque assistance to the engine. Regenerative braking is the process of stopping engine fuel injection and using the motor generator to charge the battery.

[0004] Patent Document 1 discloses a hybrid vehicle comprising: a hybrid system having an electric generator and an engine connected to a battery; and a control unit for controlling the hybrid system. In the hybrid vehicle described in Patent Document 1, the control unit calculates the rate of increase in fuel consumption relative to the output torque of the engine based on measurements from a rotation sensor that measures the engine speed and an accelerator opening sensor that measures the accelerator opening in the hybrid vehicle, and preset mapping data. Furthermore, when the maximum value of the rate of increase in fuel consumption exceeds a preset threshold, the control unit performs auxiliary control of the engine by the electric generator, starting with the maximum permissible drive output of the electric generator as measured by a temperature sensor.

[0005] For example, in a hybrid powertrain system for a car as disclosed in Patent Document 1, the required torque for the hybrid system is calculated not only based on the engine's required torque based on the accelerator pedal input (in other words, accelerator opening), but also based on the required torque of each component, such as the transmission and air conditioner. To achieve this calculation of the required torque for the hybrid system, each ECU, configured for each component, calculates the required torque for each component.

[0006] However, in industrial machinery such as construction machinery, agricultural machinery, lawnmowers, generators, compressors, and pumps, the structure of the accelerator varies depending on the application. For example, some industrial machinery does not have an accelerator pedal. In industrial machinery without an accelerator pedal, the operator uses a dial switch, such as a manual accelerator, instead of an accelerator pedal to indicate a constant engine speed in order to operate at a constant engine speed. Furthermore, in industrial machinery, it is less common for components other than the engine to have an ECU, and more common for the required torque of these components to be unclear. Thus, compared to hybrid systems in automobiles, hybrid systems in industrial machinery have a limited number of input factors available for calculating the required torque as a hybrid system, or for calculating the required torque as a hybrid system and determining the operating mode of the hybrid system.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent document 1: Japanese Patent Application Publication No. 2016-107669. Summary of the Invention

[0010] The problem the invention aims to solve

[0011] The present invention was made to solve the above-mentioned problems, and its object is to provide a hybrid power system that can calculate more appropriate desired torques when the input factors available for calculating various desired torques are limited. Alternatively, the object of the present invention is to provide a hybrid power system that can determine a more appropriate operating mode when the input factors available for determining the operating mode are limited.

[0012] means for solving problems

[0013] The aforementioned problem is solved by the hybrid power system of the present invention, which is installed in industrial machinery. The hybrid power system is characterized by comprising at least one of: a rotation sensor for detecting engine speed; an accelerator opening sensor for detecting accelerator opening degree; and a speed indicator for sending a speed signal indicating a constant engine speed to the engine; and a control unit for controlling the operation of the engine. The control unit calculates a torque determination factor for determining the torque required by the hybrid power system based on at least one of the accelerator opening degree detected by the accelerator opening sensor and the speed signal sent by the speed indicator, and performs control to calculate the torque required by the system based on the engine speed detected by the rotation sensor and the calculated torque determination factor.

[0014] According to the hybrid power system of the present invention, the control unit calculates a torque determination factor for determining the system-required torque of the hybrid power system based on at least one of the accelerator opening detected by the accelerator opening sensor and the speed signal sent by the speed indicator. That is, the control unit can calculate the torque determination factor based on the accelerator opening detected by the accelerator opening sensor, or based on the speed signal sent by the speed indicator indicating a constant engine speed, or based on both the accelerator opening and the speed signal. Then, the control unit calculates the system-required torque of the hybrid power system based on the engine speed detected by the rotation sensor and the calculated torque determination factor. Therefore, even when the hybrid power system is installed in industrial machinery without an accelerator pedal, or when the control unit is not located in a component other than the engine, the control unit of the present invention can calculate a more appropriate system-required torque. Thus, the hybrid power system of the present invention can calculate a more appropriate system-required torque even when the input factors available for calculating the system-required torque are limited.

[0015] In the hybrid power system of the present invention, the torque determining factor is preferably the fuel injection quantity of the engine.

[0016] According to the hybrid power system of the present invention, the control unit calculates the fuel injection quantity of the engine based on at least one of the accelerator opening detected by the accelerator opening sensor and the engine speed signal sent by the speed indicator. Furthermore, the control unit calculates the system-required torque as a hybrid power system based on the engine speed detected by the rotation sensor and the calculated engine fuel injection quantity. Therefore, the hybrid power system of the present invention can calculate a more appropriate system-required torque when the input factors available for calculating the system-required torque are limited.

[0017] In the hybrid power system of the present invention, the control unit preferably corrects the calculated fuel injection quantity and calculates the required engine torque for the engine based on the rotational speed detected by the rotation sensor and the corrected fuel injection quantity.

[0018] According to the hybrid power system of the present invention, the control unit corrects the fuel injection quantity and calculates the required torque of the engine based on the engine speed detected by the rotation sensor and the corrected fuel injection quantity. This reduces particulate matter (PM) in the exhaust gas and enables torque assistance in situations where engine speed drops due to overload or where rapid acceleration response is required.

[0019] In the hybrid power system of the present invention, the control unit preferably stores in advance mapping data representing the relationship between the engine speed, the fuel injection quantity and the engine torque, and calculates the torque required by the system based on the pre-stored mapping data.

[0020] According to the hybrid power system of the present invention, since the control unit calculates the torque required by the system based on pre-stored mapping data, it is possible to reduce the processing time for calculating the torque required by the system and to calculate a more appropriate torque required by the system.

[0021] In the hybrid power system of the present invention, the control unit preferably stores in advance mapping data representing the relationship between the engine speed, the fuel injection quantity and the engine torque, and calculates the required torque of the engine based on the pre-stored mapping data.

[0022] According to the hybrid power system of the present invention, since the control unit calculates the torque required by the engine based on pre-stored mapping data, it is possible to reduce the processing time for calculating the torque required by the engine and to calculate a more appropriate torque required by the engine.

[0023] In the hybrid power system of the present invention, it is characterized in that, preferably, the control unit calculates a torque required by the system that is greater than the torque generated solely by the engine.

[0024] According to the hybrid power system of the present invention, the control unit is able to perform torque assistance and generate a larger torque required by the system than that produced by the engine alone, even when the engine speed is relatively low. This allows for improved fuel economy while suppressing engine exhaust volume and reducing particulate matter in the exhaust gases.

[0025] The aforementioned problem is solved by the hybrid power system of the present invention, which is installed in industrial machinery. The hybrid power system is characterized by comprising at least one of: a rotation sensor for detecting engine speed; an accelerator opening sensor for detecting accelerator opening degree; and a speed indicator for sending a speed signal indicating a constant engine speed to the engine; and a control unit for controlling the operation of the engine. The control unit calculates a torque determination factor for determining the system torque required for the hybrid power system based on at least one of the accelerator opening degree detected by the accelerator opening sensor and the speed signal sent by the speed indicator. Based on the speed detected by the rotation sensor and the calculated torque determination factor, it calculates the system torque required and the engine torque required for the engine. Based on the relationship between the system torque required and the engine torque required, it performs control to determine the operating mode.

[0026] According to the hybrid power system of the present invention, the control unit calculates a torque determination factor for determining the system-required torque of the hybrid power system based on at least one of the accelerator opening detected by the accelerator opening sensor and the speed signal sent by the speed indicator. That is, the control unit can calculate the torque determination factor based on the accelerator opening detected by the accelerator opening sensor, or based on the speed signal sent by the speed indicator indicating a constant speed to the engine, or based on both the accelerator opening and the speed signal. Then, the control unit calculates the system-required torque of the hybrid power system and the engine-required torque based on the engine speed detected by the rotation sensor and the calculated torque determination factor, and performs control to determine the operating mode based on the relationship between the system-required torque and the engine-required torque. Therefore, even when the hybrid power system is installed in industrial machinery without an accelerator pedal, or when the control unit is not located in a component other than the engine, the control unit of the present invention can calculate a more appropriate system-required torque and engine-required torque, and determine a more appropriate operating mode based on the relationship between the system-required torque and the engine-required torque. Therefore, the hybrid power system of the present invention can determine a more appropriate operating mode when the input factors available for determining the operating mode are limited.

[0027] In the hybrid power system of the present invention, the torque determining factor is preferably the fuel injection quantity of the engine.

[0028] According to the hybrid power system of the present invention, the control unit calculates the fuel injection quantity of the engine based on at least one of the accelerator opening detected by the accelerator opening sensor and the speed signal sent by the speed indicator. Furthermore, the control unit calculates the system-required torque and the engine-required torque based on the engine speed detected by the rotation sensor and the calculated engine fuel injection quantity, and performs control to determine the operating mode based on the relationship between the system-required torque and the engine-required torque. Therefore, the hybrid power system of the present invention can determine a more appropriate operating mode even when the input factors available for determining the operating mode are limited.

[0029] In the hybrid power system of the present invention, it is characterized in that, preferably, the control unit corrects the calculated fuel injection quantity and calculates the required torque of the engine based on the rotational speed detected by the rotation sensor and the corrected fuel injection quantity.

[0030] According to the hybrid power system of the present invention, the control unit corrects the fuel injection quantity and calculates the required torque of the engine based on the engine speed detected by the rotation sensor and the corrected fuel injection quantity. This reduces the particulate matter (PM) contained in the exhaust gas and enables torque assistance as a more appropriate operating mode in cases where engine speed drops due to overload or when rapid acceleration response is required.

[0031] In the hybrid power system of the present invention, the control unit preferably stores in advance mapping data representing the relationship between the engine speed, the fuel injection quantity and the engine torque, and calculates the required torque of the system and the required torque of the engine based on the pre-stored mapping data.

[0032] According to the hybrid power system of the present invention, since the control unit calculates the required torque of the system and the required torque of the engine based on pre-stored mapping data, it is possible to reduce the processing time for calculating the required torque of the system and the required torque of the engine, and at the same time, it is possible to calculate a more appropriate required torque of the system and the required torque of the engine.

[0033] In the hybrid power system of the present invention, the control unit is characterized in that, preferably, the control unit further performs control to determine the operating mode based on the charging rate of the battery connected to the electric generator.

[0034] According to the hybrid power system of the present invention, the control unit performs control to determine the operating mode based not only on the relationship between the torque required by the system and the torque required by the engine, but also on the charging rate of the battery connected to the electric generator. Therefore, the hybrid power system of the present invention can determine a more appropriate operating mode even when the input factors available for determining the operating mode are limited.

[0035] In the hybrid power system of the present invention, it is characterized in that, preferably, when the torque required by the system is less than a first threshold and the charging rate is less than a second threshold, the control unit sets the torque required by the engine to zero and calculates the torque required by the electric motor for the electric generator, and determines the regenerative operation of charging the battery using the electric generator as the operation mode.

[0036] According to the hybrid power system of the present invention, the control unit is able to calculate the required torque of the electric motor for the electric generator based on the relationship between the torque required by the system and the torque required by the engine, as well as the charging rate of the battery, and execute regenerative operation as a more appropriate operating mode.

[0037] In the hybrid power system of the present invention, it is characterized in that, preferably, when the torque required by the system is greater than the torque required by the engine and the charging rate is greater than a second threshold, the control unit calculates the torque required by the electric motor for the electric generator based on the difference between the torque required by the system and the torque required by the engine, and determines the torque assist action of the electric generator assisting the engine torque as the operation mode.

[0038] According to the hybrid power system of the present invention, the control unit is able to calculate the required torque for the electric motor of the electric generator based on the relationship between the torque required by the system and the torque required by the engine and the charging rate of the battery, and execute torque assistance action as a more appropriate operating mode.

[0039] In the hybrid power system of the present invention, the control unit is characterized in that, preferably, in at least one of the following situations—that the torque required by the system is below the torque required by the engine and that the charging rate is below a second threshold—it calculates the torque required by the electric motor for the electric generator based on the charging rate, and determines the torque distribution action of distributing the torque of the engine and the torque of the electric generator to make the charging rate close to the target value as the operation mode.

[0040] According to the hybrid power system of the present invention, the control unit is able to calculate the required torque for the electric motor of the electric generator based on the relationship between the torque required by the system and the torque required by the engine, as well as the charging rate of the battery, and perform torque distribution action as a more appropriate operating mode.

[0041] In the hybrid power system of the present invention, it is characterized in that, preferably, the control unit calculates a torque required by the system that is greater than the torque generated solely by the engine.

[0042] According to the hybrid power system of the present invention, the control unit can perform torque assistance operation even when the engine speed is relatively low, as a more appropriate operating mode, and generate the system's required torque greater than that produced by the engine alone. This allows for improved fuel economy while suppressing engine exhaust volume and reducing particulate matter in the exhaust gases.

[0043] Invention Effects

[0044] According to the present invention, a hybrid power system is provided that can calculate more appropriate desired torques when the input factors available for calculating various desired torques are limited. Furthermore, according to the present invention, a hybrid power system is provided that can determine a more appropriate operating mode when the input factors available for determining the operating mode are limited. Attached Figure Description

[0045] Figure 1 This is a block diagram illustrating a hybrid power system according to a first embodiment of the present invention.

[0046] Figure 2 This is a block diagram illustrating a hybrid power system according to a second embodiment of the present invention.

[0047] Figure 3 This is a block diagram showing the main structure of the hybrid power system in this embodiment.

[0048] Figure 4 This is a flowchart illustrating the general operation of the hybrid power system according to this embodiment.

[0049] Figure 5 This is a flowchart illustrating a specific example of the operation of the hybrid power system in this embodiment.

[0050] Figure 6 This is a flowchart illustrating a specific example of the operation of the hybrid power system in this embodiment.

[0051] Figure 7 This is a table illustrating the mapping data in this embodiment.

[0052] Figure 8 This is a graph showing the torque curve of the hybrid power system in this embodiment. Detailed Implementation

[0053] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0054] Furthermore, the embodiments described below are preferred specific examples of the present invention, and therefore various preferred limitations have been added to the technical description. However, unless otherwise specified in the following description, the scope of the present invention is not limited to these embodiments. Additionally, in the accompanying drawings, the same reference numerals are used to denote the same constituent elements, and detailed descriptions are appropriately omitted.

[0055] Figure 1 This is a block diagram illustrating a hybrid power system according to a first embodiment of the present invention.

[0056] The hybrid power system 2A of this embodiment is, for example, installed in industrial machinery such as construction machinery, agricultural machinery, lawnmowers, generators, compressors, and pumps. Figure 1 As shown, the industrial machinery equipped with the hybrid power system 2A of this embodiment has an accelerator pedal 65, and is a machine that allows the speed of the engine 3 to be varied via the accelerator pedal 65. The hybrid power system 2A includes: an engine 3, an electric generator 41, a battery pack 42, a DC / DC converter 43, a control unit 5, and an accelerator opening sensor 61.

[0057] Engine 3 is an internal combustion engine, such as an industrial diesel engine, industrial gasoline engine, or industrial gas engine. Engine 3 can also be a turbocharged, high-output 3-cylinder or 4-cylinder engine, or other multi-cylinder engine. Figure 1 As shown, engine 3 includes: a rotation sensor 31, a DOC (Diesel Oxidation Catalyst) 32, and a DPF (Diesel Particulate Filter) 33. However, engine 3 is not limited to... Figure 1 The structure shown can also be a structure without DOC or DPF. Furthermore, engine 3 only needs to have electronically controlled fuel injection; it is not limited to common rail engines and can also be an engine with electronically controlled governors.

[0058] Rotation sensor 31 detects the rotational speed of engine 3 and sends a voltage signal related to the rotational speed of engine 3 to control unit 5 via CAN (Controller Area Network) communication line. Control unit 5 converts the received voltage signal related to the rotational speed of engine 3 into rotational speed. The power generated by engine 3 is transmitted to power extraction components 71 such as hydraulic pumps and transmissions (T / M) of industrial machinery.

[0059] The electric generator 41 is an alternator connected to the engine 3 via a transmission member 34 such as a V-belt. The electric generator 41 is driven by the power generated by the engine 3 and transmitted via the transmission member 34 to generate electricity. Furthermore, in situations where the engine speed decreases due to overload or rapid acceleration response is required, the electric generator 41 utilizes power supplied from the battery pack 42 to generate rotational force, which is then transmitted to the engine 3 via the transmission member 34, thereby assisting or supporting the torque of the engine 3. Details will be described later.

[0060] The battery pack 42, for example, is a lithium-ion battery, and is electrically connected to the electric generator 41. The battery pack 42 in this embodiment is an example of the "battery" of the present invention. The battery pack 42 is electrically connected to the electric generator 41 via a 48V system line, for example, and stores the power generated by the electric generator 41. That is, the battery pack 42 is charged by the power generated by the electric generator 41. In addition, the battery pack 42 supplies the stored power to the electric generator 41. That is, the battery pack 42 discharges when the electric generator 41 needs power, thereby supplying power to the electric generator 41.

[0061] DC / DC converter 43 is electrically connected to battery pack 42 via a high-voltage system line, such as 48V or 24V, and converts the high-voltage DC discharged from battery pack 42 into a low-voltage DC, such as 12V. Alternatively, DC / DC converter 43 is electrically connected to lead-acid battery 72 via a low-voltage system line. The power converted from high-voltage DC to low-voltage DC by DC / DC converter 43 is stored in lead-acid battery 72. The power stored in lead-acid battery 72 is supplied to electrical loads 73 of industrial machinery such as lamps, electric heaters, and windshield wipers.

[0062] As described above, the industrial machinery equipped with the hybrid power system 2A of this embodiment has an accelerator pedal 65. The accelerator opening sensor 61 detects the input of the accelerator pedal 65, i.e., the accelerator opening, and sends a signal related to the accelerator opening to the control unit 5 via a CAN communication line.

[0063] The control unit 5 includes an ECU (Electronic Control Unit, or Engine Control Unit) and an HCU (Hybrid Control Unit) to manage the hybrid system 2A. The HCU can be integrated with the ECU or installed separately from it.

[0064] The control unit 5 acquires various information or receives various signals to perform calculations and generates control signals to control the operation of components such as the engine 3, electric generator 41, and battery pack 42. These signals are then transmitted to each component via an electrical communication line, including CAN. For example, the control unit 5 calculates the fuel injection quantity of the engine 3, calculates the target air quantity of the engine 3, determines the operating mode of the hybrid power system 2A, or determines the control parameters of the engine 3. It then sends control signals to each component via the electrical communication line, thereby providing drive instructions to each component.

[0065] As for the operating modes of the hybrid power system 2A, examples include torque distribution, torque assistance, and regeneration. Torque distribution involves distributing the torque of the engine 3 and the torque of the electric generator 41 to bring the charging rate of the battery pack 42 close to a target value. Torque assistance involves the electric generator 41 assisting or supporting the torque of the engine 3. Regeneration involves stopping fuel injection from the engine 3 and charging the battery pack 42 via the electric generator 41. Details regarding the operating modes of the hybrid power system 2A will be described later.

[0066] Figure 2 This is a block diagram illustrating a hybrid power system according to a second embodiment of the present invention.

[0067] Furthermore, the structural elements of the hybrid power system 2B in the second embodiment are similar to those mentioned above. Figure 1 Since the structural elements of the hybrid power system 2A in the first embodiment are the same, repeated descriptions will be omitted as appropriate. The differences will be mainly described below.

[0068] The hybrid power system 2B in this embodiment is similar to the one mentioned above. Figure 1 The aforementioned hybrid power system 2A is similarly used in industrial machinery, such as construction machinery, agricultural machinery, lawnmowers, generators, compressors, and pumps. Figure 2 As shown, the industrial machinery equipped with the hybrid power system 2B of this embodiment has a manual accelerator 62 instead of an accelerator pedal 65, and the engine speed 3 is set to a constant speed by means of the manual accelerator 62.

[0069] To operate at a constant engine speed, the operator of the industrial machinery equipped with the hybrid power system 2B uses a manual accelerator 62 to instruct the operator to maintain a constant engine speed. The manual accelerator 62, for example, is a dial switch that receives the constant engine speed input by the operator based on their input of the manual accelerator 62, and transmits the speed signal indicating the constant engine speed to the control unit 5 via a CAN communication line. The manual accelerator 62 in this embodiment is an example of the "speed indicator" of the present invention. However, the "speed indicator" of the present invention is not limited to the manual accelerator 62.

[0070] Other structural elements are similar to those mentioned earlier. Figure 1 The hybrid power system 2A of the first embodiment has the same structural elements.

[0071] In the following description, for ease of explanation, the concepts of both the hybrid power system 2A of the first embodiment and the hybrid power system 2B of the second embodiment can be referred to as "hybrid power system 2". (As for...) Figure 1 as well as Figure 2 As described above, the hybrid power system 2 of this embodiment can be installed in industrial machinery equipped with an accelerator pedal 65, or in industrial machinery that does not have an accelerator pedal 65 (in other words, has a manual accelerator 62). Furthermore, the hybrid power system 2 of this embodiment can also be installed in industrial machinery equipped with both an accelerator pedal 65 and a manual accelerator 62.

[0072] Next, the control unit 5 of this embodiment will be further described with reference to the accompanying drawings.

[0073] Figure 3 This is a block diagram showing the main structure of the hybrid power system in this embodiment.

[0074] The control unit 5 of this embodiment includes an arithmetic unit 51, a storage unit 52, and a communication unit 53. The arithmetic unit 51 reads the program 521 stored in the storage unit 52 and performs various calculations or processes. The storage unit 52 stores the program 521 executed by the arithmetic unit 51 and mapping data 522 used when calculating the torque required by the system and the torque required by the engine, which will be described later. Details about the mapping data 522 will be described later. Furthermore, the data stored in the storage unit 52 is not limited to the program 521 and the mapping data 522. Examples of storage units 52 include ROM (Read Only Memory) or RAM (Random Access Memory). Furthermore, the program 521 is not limited to being stored in the storage unit 52; it can be pre-stored in a storage medium readable by the arithmetic unit 51 and distributed, or it can be downloaded to the control unit 5 via a network. In addition, the storage unit 52 can also be an external storage device connected to the control unit 5.

[0075] The arithmetic unit 51 includes: a fuel injection quantity calculation unit 511, a system required torque calculation unit 512, an engine required torque calculation unit 513, an electric motor required torque calculation unit 514, an operation mode determination unit 515, and an engine control parameter determination unit 516. Alternatively, the arithmetic unit 51 may also include both a fuel injection quantity calculation unit 511 and a target air quantity calculation unit (not shown) instead of the fuel injection quantity calculation unit 511. The fuel injection quantity calculation unit 511, the system required torque calculation unit 512, the engine required torque calculation unit 513, the electric motor required torque calculation unit 514, the operation mode determination unit 515, the engine control parameter determination unit 516, and the target air quantity calculation unit are implemented by the arithmetic unit 51 executing a program 521 stored in the storage unit 52. Furthermore, the fuel injection quantity calculation unit 511, the system required torque calculation unit 512, the engine required torque calculation unit 513, the electric motor required torque calculation unit 514, the operation mode determination unit 515, the engine control parameter determination unit 516, and the target air quantity calculation unit can be implemented in hardware or in a combination of hardware and software.

[0076] The calculation unit 51 calculates torque determination factors for determining the torque required for the hybrid power system 2 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. The torque determination factors include the fuel injection quantity of the engine 3 and the target air quantity of the engine 3. In other words, the "fuel injection quantity" and "target air quantity" in this embodiment are examples of the "torque determination factors" of the present invention. That is, the calculation unit 51 can calculate the fuel injection quantity of the engine 3 and the target air quantity of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. In the following description, the case where the "torque determination factor" is the "fuel injection quantity" is taken as an example.

[0077] The fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. That is, the fuel injection quantity calculation unit 511 can calculate the fuel injection quantity of the engine 3 based on the accelerator opening detected by the accelerator opening sensor 61, or it can calculate the fuel injection quantity of the engine 3 based on the speed signal sent by the manual accelerator 62. Alternatively, the fuel injection quantity calculation unit 511 can calculate the fuel injection quantity of the engine 3 based on both the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. Furthermore, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515. As described above, the fuel injection quantity of the engine 3 in this embodiment is an example of the "torque determination factor" of the present invention.

[0078] The system torque calculation unit 512 calculates the system torque required as the hybrid power system 2. Specifically, the system torque calculation unit 512 calculates the system torque required based on the engine speed 3 detected by the rotation sensor 31 and the fuel injection quantity calculated by the fuel injection quantity calculation unit 511. For example, the system torque calculation unit 512 calculates the system torque required based on mapping data 522 that represents the relationship between the engine speed 3, the fuel injection quantity of the engine 3, and the torque of the engine 3. Furthermore, the system torque calculation unit 512 is not limited to calculating the system torque required based on the mapping data 522; for example, it may also calculate the system torque required based on mathematical formulas or graphs representing the relationship between the engine speed 3, the fuel injection quantity of the engine 3, and the torque of the engine 3.

[0079] The engine torque calculation unit 513 calculates the required torque for engine 3. Specifically, the engine torque calculation unit 513 calculates the required torque based on the engine speed of 3 detected by the rotation sensor 31 and the fuel injection quantity calculated by the fuel injection quantity calculation unit 511. For example, the engine torque calculation unit 513 corrects the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 and calculates the required torque based on the engine speed of 3 detected by the rotation sensor 31 and the corrected fuel injection quantity. For example, after correcting the fuel injection quantity calculated by the fuel injection quantity calculation unit 511, the engine torque calculation unit 513 calculates the required torque based on the mapping data 522 representing the relationship between the engine speed of 3, the fuel injection quantity of 3, and the torque of 3. Furthermore, the engine torque calculation unit 513 is not limited to calculating the engine torque based on the mapping data 522. For example, after correcting the fuel injection quantity calculated by the fuel injection quantity calculation unit 511, the engine torque can also be calculated based on a mathematical formula or graph representing the relationship between the engine speed, the fuel injection quantity of the engine 3 and the torque of the engine 3.

[0080] The electric motor torque calculation unit 514 calculates the required torque for the electric motor in relation to the electric generator 41. Specifically, the electric motor torque calculation unit 514 calculates the required torque for the electric motor based on the operating mode of the hybrid system 2 determined by the operating mode determination unit 515. More specifically, the electric motor torque calculation unit 514 calculates the required torque for the electric motor based on the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the engine torque required by the engine torque required by the engine torque required by the system ...

[0081] The operation mode determination unit 515 determines the operation mode of the hybrid power system 2. Specifically, the operation mode determination unit 515 determines which operation mode among regenerative operation, torque assist operation, and torque distribution operation should be used as the operation mode of the hybrid power system 2. More specifically, the operation mode determination unit 515 determines the operation mode of the hybrid power system 2 based on 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. Alternatively, the operation mode determination unit 515 determines the operation mode of the hybrid power system 2 based on 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, and the engine speed detected by the rotation sensor 31.

[0082] The engine control parameter determination unit 516 determines the control parameters of the engine 3 based on the fuel injection quantity of the engine 3 calculated according to the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 and the engine speed of the engine 3 detected by the rotation sensor 31. In other words, the engine control parameter determination unit 516 determines the control parameters of the engine 3 based on the fuel injection quantity written back (i.e., the converted) according to the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 and the engine speed of the engine 3 detected by the rotation sensor 31. Examples of control parameters for the engine 3 include, for example, the injection mode of the engine 3, the injection timing of the engine 3, and the opening degree of the EGR (Exhaust Gas Recirculation) valve.

[0083] The communication unit 53 communicates with at least one of the following via an electrical communication line: a rotation sensor 31, an accelerator opening sensor 61, and a manual accelerator 62; an electric generator 41; a battery pack 42; and a DC / DC converter 43, thereby transmitting and receiving various information or signals.

[0084] Among them, as mentioned above Figure 1 as well as Figure 2 As described above, the structure of the accelerator varies depending on the application in construction machinery, agricultural machinery, and industrial machinery such as lawnmowers, generators, compressors, and pumps. For example, there are industrial machines that do not have an accelerator pedal 65. In industrial machines that do not have an accelerator pedal 65, the operator uses a manual accelerator 62 to indicate a constant engine speed. Furthermore, in industrial machinery, it is relatively rare for components other than the engine 3 to have an ECU, and it is more common for the required torque of components other than the engine 3 to be unclear. Thus, compared to a hybrid system installed in a car, the input factors that can be used to calculate the system torque required by the hybrid system 2 installed in industrial machinery are limited.

[0085] In this embodiment, the control unit 5 (specifically, the fuel injection quantity calculation unit 511) of the hybrid power system 2 calculates the fuel injection quantity of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. Furthermore, the control unit 5 (specifically, the system required torque calculation unit 512) calculates the system required torque of the hybrid power system 2 based on the engine speed detected by the rotation sensor 31 and the fuel injection quantity of the engine 3 calculated by the fuel injection quantity calculation unit 511. Additionally, the control unit 5 (specifically, the engine required torque calculation unit 513) calculates the engine required torque based on the engine speed detected by the rotation sensor 31 and the fuel injection quantity calculated by the fuel injection quantity calculation unit 511. For example, the engine required torque calculation unit 513 corrects the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 and calculates the engine required torque based on the engine speed detected by the rotation sensor 31 and the corrected fuel injection quantity.

[0086] According to the hybrid power system 2 of this embodiment, even when the hybrid power system 2 is installed in industrial machinery that does not have an accelerator pedal 65, or when the control unit 5 is not located in a component other than the engine 3, the control unit 5 of this embodiment can calculate a more appropriate system torque and engine torque. Therefore, the hybrid power system 2 of this embodiment can calculate a more appropriate system torque and engine torque even when the input factors available for calculating the system torque are limited. Furthermore, the control unit 5 (specifically, the operating mode determination unit 515) can determine a more appropriate operating mode based on the relationship between the system torque and the engine torque. Therefore, the hybrid power system 2 of this embodiment can determine a more appropriate operating mode even when the input factors available for determining the operating mode are limited.

[0087] Furthermore, the control unit 5 (specifically, the operating mode determination unit 515) determines the operating mode not only based on the relationship between the torque required by the system and the torque required by the engine, but also based on the charging rate of the battery pack 42 connected to the electric generator 41. Therefore, the hybrid power system 2 can determine a more appropriate operating mode when the input factors available for determining the operating mode are limited.

[0088] Next, the operation of the hybrid power system of this embodiment will be described with reference to the accompanying drawings.

[0089] Figure 4 This is a flowchart illustrating the general operation of the hybrid power system according to this embodiment.

[0090] First, in step S11, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. The fuel injection quantity calculated in step S11 is the fuel injection quantity before correction is performed to avoid excessive emission of particulate matter (PM) contained in the exhaust gas or to prevent the output of the engine 3 from exceeding the limit value. Furthermore, the system required torque calculation unit 512 calculates the system required torque based on the engine speed detected by the rotation sensor 31 and the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 (i.e., the fuel injection quantity before correction).

[0091] Next, in step S12, the engine torque calculation unit 513 corrects the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 to avoid excessive emission of particulate matter contained in the exhaust gas or to prevent the output of the engine 3 from exceeding the limit value, and finally determines the maximum fuel injection quantity. Furthermore, the engine torque calculation unit 513 calculates the engine torque required based on the engine speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection quantity.

[0092] Next, in step S13, the operation mode determination unit 515 determines the operation mode (regenerative operation, torque assist operation, torque distribution operation) of the hybrid power system 2 based on the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the system torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the engine torque required by the system ... engine

[0093] Next, in step S14, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515. That is, the fuel injection quantity calculation unit 511 performs a write-back (i.e., conversion) of the fuel injection quantity of the engine 3 based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515.

[0094] Furthermore, in step S15, the motor torque calculation unit 514 calculates the motor torque required based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515. The control unit 5 then sends a signal related to the motor torque required calculated by the motor torque calculation unit 514 to the electric generator 41, instructing the electric generator 41.

[0095] Next, in step S16, the engine control parameter determination unit 516 determines the control parameters of the engine 3 based on the fuel injection quantity written back by the fuel injection quantity calculation unit 511 and the engine speed of the engine 3 detected by the rotation sensor 31.

[0096] Next, in step S17, the control unit 5 sends a signal related to the control parameters determined by the engine control parameter determination unit 516 to give drive instructions to each device.

[0097] According to the hybrid power system 2 of this embodiment, the control unit 5 corrects the fuel injection quantity calculated by the fuel injection quantity calculation unit 511, and calculates the required torque of the engine based on the engine speed of the engine 3 detected by the rotation sensor 31 and the corrected fuel injection quantity. This reduces particulate matter contained in the exhaust gas, and enables torque assistance, for example, in cases where the engine speed of the engine 3 decreases due to overload or when rapid acceleration response is required.

[0098] Figure 5 as well as Figure 6 This is a flowchart illustrating a specific example of the operation of the hybrid power system in this embodiment.

[0099] Figure 7 This is a table illustrating the mapping data in this embodiment.

[0100] like Figure 5 As shown, firstly, in step S21, the control unit 5 determines whether an error has occurred in the hybrid power system 2. If an error has occurred in the hybrid power system 2 ("yes" in step S21), the control unit 5 terminates the operation of the hybrid power system 2.

[0101] If no error occurs in the hybrid system 2 (No in step S21), in step S23, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. Furthermore, the system required torque calculation unit 512 calculates the system required torque based on the engine speed detected by the rotation sensor 31 and the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 (i.e., the fuel injection quantity before correction). Additionally, the engine required torque calculation unit 513 corrects the fuel injection quantity calculated by the fuel injection quantity calculation unit 511 and calculates the engine required torque based on the engine speed detected by the rotation sensor 31 and the corrected fuel injection quantity. The terms "fuel injection quantity before correction" and "fuel injection quantity after correction" are as described above regarding... Figure 4 As described above. In this embodiment, the control unit 5 calculates the required torque of the system and the required torque of the engine based on the mapping data 522 pre-stored in the storage unit 52.

[0102] That is, for example Figure 7 The mapping data 522 shown is saved (stored) in the storage unit 52. Figure 7 In the illustrated mapping data 522, the horizontal axis represents the engine speed of engine 3, and the vertical axis represents the fuel injection quantity of engine 3. Additionally, in Figure 7 In the illustrated mapping data 522, the portion where the horizontal axis (engine speed) and the vertical axis (fuel injection quantity) intersect represents the torque of engine 3. That is, Figure 7 The illustrated mapping data 522 represents the relationship between the engine speed of engine 3, the fuel injection quantity of engine 3, and the torque of engine 3.

[0103] On the horizontal axis, the side with a relatively higher engine speed is to the right, and the side with a relatively lower engine speed is to the left. On the vertical axis, the side with a relatively higher fuel injection volume is to the bottom, and the side with a relatively lower fuel injection volume is to the top.

[0104] In the description of this embodiment, as follows: Figure 7 As shown, an example is given of a case where the fuel injection quantity calculation unit 511 calculates the fuel injection quantity Q8 of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. The fuel injection quantity Q8 is an example of the "fuel injection quantity before correction". Furthermore, in this embodiment description, as... Figure 7 As shown, an example illustrates the situation where the rotation sensor 31 detects the rotational speed R3 of the engine 3.

[0105] In this case, the system torque calculation unit 512 calculates the system torque T38 based on the engine speed R3 and the pre-corrected fuel injection quantity Q8. Next, the engine torque calculation unit 513 corrects the fuel injection quantity Q8 calculated by the fuel injection quantity calculation unit 511 to avoid excessive emission of particulate matter contained in the exhaust gas or to prevent the engine output from exceeding the limit value, and finally determines the maximum fuel injection quantity Q5. The fuel injection quantity Q5 is an example of the "corrected fuel injection quantity". Then, the engine torque calculation unit 513 calculates the engine torque T35 based on the engine speed R3 and the corrected fuel injection quantity Q5. In this way, the control unit 5 of this embodiment calculates the system torque T38 and the engine torque T35 based on the mapping data 522 pre-stored in the storage unit 52.

[0106] like Figure 5 As shown, in step S24 following step S23, the control unit 5 determines whether the required torque T38 of the system is less than threshold Th1 and whether the charging rate of the battery pack 42 is less than threshold Th2. Threshold Th1 in this embodiment is an example of the "first threshold" of the present invention. Threshold Th2 in this embodiment is an example of the "second threshold" of the present invention.

[0107] In step S24, if all conditions are met ("the required torque of the system T38 < threshold Th1" and "the charging rate of the battery pack 42 < threshold Th2") ("Yes" in step S24), in step S25, the operation mode determination unit 515 determines the regeneration operation as the operation mode of the hybrid power system 2 and executes the regeneration operation.

[0108] For example, in the case of an industrial machine equipped with hybrid power system 2 going downhill with the accelerator off, and all the conditions such as "the required torque of the system T38 < threshold Th1" and "the charging rate of the battery pack 42 < threshold Th2" are met, in step S25, the operation mode determination unit 515 determines the regeneration operation as the operation mode of hybrid power system 2.

[0109] Furthermore, in step S25, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 (regenerative operation in step S25). Specifically, the fuel injection quantity calculation unit 511 sets the fuel injection quantity of the engine 3 to zero. In other words, the engine required torque calculation unit 513 sets the engine required torque to zero. Additionally, in step S25, the electric motor required torque calculation unit 514 calculates the electric motor required torque based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 (regenerative operation in step S25). Specifically, the electric motor required torque calculation unit 514 calculates the electric motor required torque for charging the battery pack 42 using the electric generator 41. That is, the electric motor required torque calculation unit 514 sets the electric motor required torque to zero.

[0110] On the other hand, in step S24, if at least one of the conditions "the required torque of the system T38 < threshold Th1" and "the charging rate of the battery pack 42 < threshold Th2" is not met ("No" in step S24), in step S31, the control unit 5 determines whether the required torque of the system T38 is greater than the required torque of the engine T35 and whether the charging rate of the battery pack 42 is greater than the threshold Th2.

[0111] In step S31, if all the conditions of "the required torque of the system T38 is greater than the required torque of the engine T35" and "the charging rate of the battery pack 42 is greater than the threshold Th2" are met ("Yes" in step S31), in step S32, the operation mode determination unit 515 determines the torque assist operation as the operation mode of the hybrid power system 2 and executes the torque assist operation.

[0112] For example, in cases where an industrial machine equipped with the hybrid power system 2 is going uphill and the engine speed of the engine 3 drops due to overload, or in cases where rapid acceleration response is required, and all the conditions of "the required torque of the system T38 > the required torque of the engine T35" and "the charging rate of the battery pack 42 > the threshold Th2" are met, in step S32, the operation mode determination unit 515 determines the torque assist operation as the operation mode of the hybrid power system 2.

[0113] Furthermore, in step S32, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 (torque assist operation in step S32). Additionally, in step S32, the electric motor required torque calculation unit 514 calculates the electric motor required torque based on the operating mode of the hybrid power system 2 determined by the operating mode determination unit 515 (torque assist operation in step S32). Specifically, the electric motor required torque calculation unit 514 calculates the electric motor required torque based on the difference between the system required torque T38 and the engine required torque T35. That is, the electric motor required torque calculation unit 514 calculates the electric motor required torque for the electric generator 41 to assist the engine 3. Therefore, the hybrid power system 2 can improve the operation of industrial machinery equipped with the hybrid power system 2.

[0114] On the other hand, in step S31, if at least one of the conditions "the required torque of the system T38 > the required torque of the engine T35" and "the charging rate of the battery pack 42 > the threshold Th2" is not met, in other words, if at least one of the conditions "the required torque of the system T38 ≤ the required torque of the engine T35" and "the charging rate of the battery pack 42 ≤ the threshold Th2" is met (in step S31, it is "No"), in step S33, the operation mode determination unit 515 determines the torque distribution operation as the operation mode of the hybrid power system 2 and executes the torque distribution operation.

[0115] For example, in cases where industrial machinery equipped with hybrid power system 2 is traveling on flat ground and at least one of the conditions "the required torque of the system T38 > the required torque of the engine T35" and "the charging rate of the battery pack 42 > the threshold Th2" is not met, in step S33, the operation mode determination unit 515 determines the torque distribution operation as the operation mode of hybrid power system 2.

[0116] Furthermore, in step S33, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity of the engine 3 based on the operating mode of the hybrid system 2 determined by the operating mode determination unit 515 (torque distribution operation in step S33). Additionally, in step S33, the electric motor required torque calculation unit 514 calculates the electric motor required torque based on the operating mode of the hybrid system 2 determined by the operating mode determination unit 515 (torque distribution operation in step S33).

[0117] Specifically, for example, let's take the case where the system requires a torque of 100 N·m and the engine 3 can produce a torque of 150 N·m as an example. In this case, for example, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity required to produce a torque of 100 N·m for the engine 3. Alternatively, the fuel injection quantity calculation unit 511 sets the fuel injection quantity of the engine 3 to zero, and the electric motor required torque calculation unit 514 calculates the electric motor required to assist the electric generator 41 in providing a torque of 100 N·m to the engine 3. Alternatively, for example, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity required to produce a torque of 50 N·m for the engine 3, and the electric motor required torque calculation unit 514 calculates the electric motor required to assist the electric generator 41 in providing a torque of 50 N·m to the engine 3. Alternatively, for example, the fuel injection quantity calculation unit 511 calculates the fuel injection quantity for generating a torque of 130 N·m in the engine 3, and the electric motor required torque calculation unit 514 calculates an additional 30 N·m of torque in the engine 3 as the torque required by the electric motor for charging the battery pack 42 via the electric generator 41.

[0118] Thus, if at least one of the conditions "the required torque of the system T38 > the required torque of the engine T35" and "the charging rate of the battery pack 42 > the threshold Th2" is not met ("No" in step S31), the control unit 5 can allocate the torque of the engine 3 and the torque of the electric generator 41 so that the charging rate of the battery pack 42 is close to the target value.

[0119] After steps S25, S32 and S33, the control unit 5 terminates the operation of the hybrid power system 2.

[0120] Based on the above... Figures 5-7 In a specific example, the control unit 5 corrects the fuel injection quantity Q8 calculated by the fuel injection quantity calculation unit 511, and calculates the required engine torque T35 based on the engine speed R3 detected by the rotation sensor 31 and the corrected fuel injection quantity Q5. This reduces particulate matter in the exhaust gas and, for example, performs torque assist in situations where the engine speed decreases due to overload or when rapid acceleration response is required.

[0121] Furthermore, the control unit 5 calculates the system-required torque T38 and the engine-required torque T35 based on the mapping data 522 pre-stored in the storage unit 52. Therefore, the control unit 5 can reduce the processing time for calculating the system-required torque T38 and the engine-required torque T35, and can calculate a more appropriate system-required torque T38 and engine-required torque T35.

[0122] Furthermore, the control unit 5 determines the operating mode not only based on the relationship between the system's required torque T38 and the engine's required torque T35, but also based on the charging rate of the battery pack 42 connected to the electric generator 41. Therefore, even with limited input factors available when determining the operating mode, the control unit 5 can determine a more appropriate operating mode.

[0123] Figure 8 This is a graph showing the torque curve of the hybrid power system in this embodiment.

[0124] Figure 8 The horizontal axis of the graph shown represents the rotational speed of engine 3. Figure 8 The vertical axis of the graph shown represents the torque of engine 3.

[0125] like Figure 8 As shown, in this embodiment, the control unit 5 (specifically, the system torque calculation unit 512) calculates a system torque greater than the torque generated by the engine 3 alone across the entire speed range of the engine 3. That is, the control unit 5 controls the electric generator 41 to assist or support the torque of the engine 3, thereby generating torque in the range of engine 3 speeds that the engine 3 alone cannot produce. In other words, the control unit 5 does not control the electric generator 41 to assist or support the torque of the engine 3 in the range of torque that the engine 3 alone can produce.

[0126] Therefore, even when the engine speed of the engine 3 is relatively low, the control unit 5 can perform torque assistance as a more appropriate operating mode and generate the system's required torque, which is greater than the torque generated by the engine 3 alone. This allows for improved fuel economy while suppressing the exhaust volume of the engine 3 and reducing particulate matter in the exhaust gas.

[0127] 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. A portion of the structure of the above embodiments may be omitted, or it may be arbitrarily combined in a manner different from that described above.

[0128] As mentioned above Figure 3 The calculation unit 51 can also calculate the target air volume as a torque determining factor for determining the torque required by the system. In this case, the calculation unit 51 calculates the target air volume of the engine 3 based on at least one of the accelerator opening detected by the accelerator opening sensor 61 and the speed signal sent by the manual accelerator 62. Then, the calculation unit 51 calculates the torque required by the hybrid power system 2 based on the speed of the engine 3 detected by the rotation sensor 31 and the calculated target air volume of the engine 3. Thus, the same effects as those described above regarding the embodiments of the present invention can be obtained.

[0129] Explanation of reference numerals in the attached figures:

[0130] 2, 2A, 2B: Hybrid power system; 3: Engine; 5: Control unit; 31: Rotation sensor; 32: DOC; 33: DPF; 34: Transmission component; 41: Electric generator; 42: Battery pack; 43: DC / DC converter; 51: Computation unit; 52: Storage unit; 53: Communication unit; 61: Accelerator opening sensor; 62: Manual accelerator; 65: Accelerator pedal; 71: Power extraction component; 72: Lead-acid battery; 73: 12V load; 511: Fuel injection quantity calculation unit; 512: System required torque calculation unit; 513: Engine required torque calculation unit; 514: Electric motor required torque calculation unit; 515: Operation mode determination unit; 516: Engine control parameter determination unit; 521: Program; 522: Mapping data; Q5, Q8: Fuel injection quantity; R3: Speed; T35: Engine required torque; T38: System required torque; Th1, Th2: Threshold.

Claims

1. A hybrid power system, installed in industrial machinery, characterized in that, have: A rotary sensor that detects the engine speed; At least one of an accelerator opening sensor that detects the accelerator opening degree and a speed indicator that sends a speed signal indicating a constant speed to the engine; and The control unit that controls the operation of the engine. The control unit performs the following control: calculating a first fuel injection quantity for determining the system torque required for the hybrid system based on at least one of the accelerator opening detected by the accelerator opening sensor and the speed signal sent by the speed indicator; calculating the system torque required based on the speed detected by the rotation sensor and the first fuel injection quantity; correcting the first fuel injection quantity and determining a second fuel injection quantity as the maximum fuel injection quantity used to prevent the engine output from exceeding the limit value at the speed detected by the rotation sensor; calculating the engine torque required for the engine based on the speed detected by the rotation sensor and the second fuel injection quantity; determining an operating mode based on the relationship between the system torque required and the engine torque required; and calculating the engine fuel injection quantity based on the operating mode.

2. The hybrid power system as described in claim 1, characterized in that, The control unit determines the engine control parameters based on the fuel injection quantity of the engine calculated based on the operating mode and the rotational speed detected by the rotation sensor.

3. The hybrid power system as described in claim 1, characterized in that, The control unit pre-stores mapping data representing the relationship between the engine speed, the first fuel injection quantity, and the engine torque, and calculates the torque required by the system based on the pre-stored mapping data.

4. The hybrid power system as described in claim 1, characterized in that, The control unit pre-stores mapping data representing the relationship between the engine speed, the second fuel injection quantity, and the engine torque, and calculates the required torque of the engine based on the pre-stored mapping data.

5. The hybrid power system as described in claim 1, characterized in that, The control unit calculates the torque required by the system that is greater than the torque generated by the engine alone.

6. The hybrid power system as claimed in claim 1, characterized in that, The control unit also performs control to determine the operating mode based on the charging rate of the battery connected to the electric generator.

7. The hybrid power system as described in claim 6, characterized in that, When the required torque of the system is less than a first threshold and the charging rate is less than a second threshold, the control unit sets the required torque of the engine to zero, calculates the required torque of the motor for the electric generator, and determines the regenerative operation of charging the battery by the electric generator as the operation mode.

8. The hybrid power system as described in claim 6, characterized in that, When the torque required by the system is greater than the torque required by the engine and the charging rate is greater than a second threshold, the control unit calculates the torque required by the electric motor for the electric generator based on the difference between the torque required by the system and the torque required by the engine, and determines the torque assist action of the electric generator assisting the engine's torque as the operation mode.

9. The hybrid power system as described in claim 6, characterized in that, In at least one of the following situations, the control unit calculates the required torque for the electric motor of the electric generator based on the charging rate, and determines the operation mode as a torque distribution action that distributes the torque of the engine and the torque of the electric generator to make the charging rate close to the target value.

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