Drive unit

Abstract

The present invention provides a drive device that can reduce the time required to switch between a series mode, in which power generation is performed by an engine, and a parallel mode, in which the device is driven by the driving force of at least one of the engine or motor, while suppressing fluctuations in drive output, and reducing variations in this time. [Solution] The control device 60 of the drive unit 1 controls at least one of the engine 10 or the power generator motor MG1 to bring the rotational speed difference between the first friction surface 41 and the second friction surface 42 close to zero when the drive force is disconnected in the drive force transmission path PT1. This prevents the drive force from being maintained in an intermediate drive force connection state where a lower drive force is transmitted than the drive force transmitted when the drive force is connected in the drive force transmission path PT1. Instead, the clutch 40 is activated, and after the characteristic physical quantity Prm reaches a value indicating the drive force connection state, the control device 60 controls at least one of the engine 10 or the drive motor MG2 to change the drive force that drives the drive output member 30.

Description

Technical Field

[0001] This invention relates to a drive device.

Background Art

[0002] Vehicles having a hybrid drive device that combines an engine and a motor are known. Also, it is known that there are various types of hybrid drive devices depending on the differences in the power generation and driving methods.

[0003] For example, Patent Document 1 discloses a vehicle that switches between a series hybrid mode and an internal combustion engine direct connection mode according to the driving state. In the series hybrid mode, the driving force from the internal combustion engine is transmitted to the power generation motor, while the driving force from the driving motor is transmitted to the drive wheels. Also, in the internal combustion engine direct connection mode, the driving force from the internal combustion engine is transmitted to the drive wheels.

[0004] In the vehicle of Patent Document 1, a clutch mechanism is used to switch the power source that transmits the driving force to the drive wheels. The vehicle switches the power source to the internal combustion engine or the driving motor according to the mode. A so-called dog clutch is adopted in the clutch mechanism of Patent Document 1. The dog clutch is a clutch in which one clutch component to which the driving force is input and the other clutch component from which the driving force is output are fastened by dog teeth that mesh with each other instead of frictional force, thereby transmitting power from the one clutch component to the other clutch component.

[0005] In the vehicle described in Patent Document 1, for example, a clutch mechanism located in the transmission path that transmits driving force from the internal combustion engine to the drive wheels includes a reduction gear provided on the output shaft of the internal combustion engine and a sleeve that meshes with the reduction gear. The sleeve is configured to be movable in the axial direction of the output shaft of the internal combustion engine relative to the reduction gear. The sleeve and the reduction gear each have dog teeth that protrude in opposite directions and are positioned side by side in the rotational direction. In the engagement operation of the clutch mechanism, the sleeve moves toward the reduction gear in the rotational direction, causing the dog teeth of both to mesh alternately in the rotational direction. This causes the clutch mechanism to be engaged. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2022 / 106862 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0007] Incidentally, in a dog clutch, when one clutch component approaches the other, the protrusions of the teeth on one dog clutch may interfere with the protrusions of the teeth on the other dog clutch (this interference is also called "teeth-on-teeth"). For this reason, in the clutch control device of the vehicle described in Patent Document 1, the clutch engagement operation of the clutch mechanism is started before the difference in rotational speed becomes zero, while bringing the rotational speeds of the two clutch components closer together. This makes it possible to shift the phase of rotation between the dog teeth even if teeth-on-teeth occurs. As a result, teeth-on-teeth is eliminated, and clutch engagement proceeds again.

[0008] Therefore, from another perspective, the clutch control device of Patent Document 1 is configured in such a way that the difference in rotation between the two clutch components cannot be made zero in order to eliminate teeth-on-teeth contact. For this reason, the configuration of Patent Document 1 has the following characteristics.

[0009] First, in the configuration described in Patent Document 1, the control is complex because the rotational speed of one clutch must be adjusted so that a differential rotation always occurs between the two clutch components. Consequently, it takes time to complete the rotational synchronization phase in which the differential rotation is introduced. This also increases the time required to complete the clutch engagement operation.

[0010] Furthermore, in the configuration of Patent Document 1 described above, if teeth-on-teeth occurs when the difference in rotational speed between the two clutch components is not zero, as described above, the teeth-on-teeth issue is resolved when the phase of rotational speed of the two clutch components is shifted due to the difference in rotation, and the teeth mesh alternately in the rotational direction. In this case, in the clutch mechanism, the difference in rotational speed between the two clutch components becomes zero due to the contact between the respective dog teeth, so fluctuations in driving force occur during the clutch engagement operation.

[0011] Furthermore, in the configuration of Patent Document 1 described above, the dog teeth of the two clutch components are configured to have a gap between them when they are engaged. Therefore, in the clutch mechanism, even if the dog teeth of the other clutch component enter between the dog teeth of the one clutch component as the clutch engagement progresses, there is a time lag before the dog teeth of the one clutch component move in the rotational direction and come into contact with the dog teeth of the other clutch component.

[0012] Furthermore, in the configuration of Patent Document 1 described above, if teeth-on-teeth occurs, it may be necessary to shift the phase by the width of the dog teeth in the rotational direction in order to resolve the teeth-on-teeth issue. Therefore, the time required to resolve the teeth-on-teeth issue may vary depending on the positional relationship of the dog teeth of the two clutch components.

[0013] Therefore, in a dog clutch, there is variation in the time required for the clutch engagement phase depending on whether teeth-on-teeth occurs and the clutch engages quickly, or whether teeth-on-teeth occurs, takes time to resolve, and delays clutch engagement.

[0014] Therefore, it is desirable to achieve both the suppression of fluctuations in drive output when the clutch engages and the suppression and reduction of variations in the time until the clutch engages.

[0015] The present invention aims to provide a drive device that can reduce the time required to switch between a series mode, in which power generation is performed by an engine, and a parallel mode, in which the device is driven by the driving force of at least one of the engine or motor, while suppressing fluctuations in drive output, and reducing variations in this time. [Means for solving the problem]

[0016] The inventors investigated a drive device that can reduce the time required to switch between a series mode, in which power generation is performed by an engine, and a parallel mode, in which the device is driven by the driving force of at least one of the engine or motor, while suppressing fluctuations in drive output, and while minimizing variations. As a result of diligent investigation, the inventors came up with the following configuration.

[0017] A drive device according to one embodiment of the present invention comprises an engine, a power generation motor that functions as at least a generator when driven by the engine, a battery, a drive output member that outputs driving force, a drive motor that is rotationally driven by at least the power supplied from the battery and connected to the drive output member so as to transmit rotational force, a clutch provided in the driving force transmission path between the drive output member and the engine and switching the driving force transmission path between a driving force disconnected state and a driving force connected state, and a control device that controls the engine, the power generation motor, the drive motor, and the clutch. The clutch is a friction clutch that is not a meshing clutch, and has a first friction surface and a second friction surface, each provided with a friction material, and the first and second friction surfaces are positioned side by side in a relative movement direction which is the axial or radial direction of the rotation axis of the first and second friction surfaces, and when switching from the driving force disconnected state, in which the first and second friction surfaces are separated in the relative movement direction, to the driving force connected state, the driving force of the engine is transmitted to the driving force transmission path, and a characteristic physical quantity, including at least one of a physical quantity related to the relative position of the first and second friction surfaces, which is a physical quantity other than the rotational speed difference between the first and second friction surfaces, and a physical quantity related to the pressure or current pressing between the first and second friction surfaces, has different characteristics in the driving force disconnected state and the driving force connected state. When the control device is operating in a normal state, and the drive unit is in a series mode in which the power generator motor is driven by the engine's driving force when the driving force transmission path by the clutch is disconnected, and the drive motor is driven using at least that power, the control device switches to a parallel mode in which the drive output member is driven by at least one of the driving forces of the engine and the drive motor when the driving force transmission path by the clutch is connected, [a] Control at least one of the engine or the power generation motor so as to suppress the rotational speed synchronization effect due to frictional contact between the first friction surface and the second friction surface when the clutch is operated, thereby bringing the rotational speed difference between the first friction surface and the second friction surface close to zero when the drive force is disconnected in the drive force transmission path by the clutch, [b] Without maintaining the clutch in an intermediate drive force connection state in which a drive force lower than the drive force transmitted in the drive force connection state of the drive force transmission path, the clutch is activated so that the characteristic physical quantity reaches a value indicating the drive force connection state, and then at least one of the engine or the drive motor is controlled to change the drive force that drives the drive output member.

[0018] In the above configuration, when the control device switches the driving mode from series mode to parallel mode, the engine is not affected by the drive output member because the drive force transmission path is in a drive force disconnected state. Furthermore, the generator motor can be controlled electrically with good responsiveness. The control device controls the engine or the generator motor so that the difference in rotational speed between the first friction surface and the second friction surface approaches zero when the clutch is operated in order to suppress the synchronization effect of rotational speed. Furthermore, the control device controls the clutch to move from a drive force disconnected state to a drive force connected state without being maintained in a drive force intermediate connected state. As a result, the drive device can suppress fluctuations in the rotational speed of the drive output member when the drive from the engine is transmitted to the drive output member driven by the drive motor. In addition, the drive device can transmit the drive force from the first friction surface to the second friction surface in a shorter time and with less loss compared to the case where the first friction surface and the second friction surface are connected via a drive force intermediate connected state in which they are in contact while rotating at different rotational speeds.

[0019] Furthermore, after the rotational speed difference approaches zero, the control device activates a friction clutch, which is not a meshing clutch, from a drive force disconnected state to a drive force connected state without maintaining the drive force intermediate connected state. The control device determines whether the drive force transmission path has entered a drive force connected state by the characteristic physical quantity, which is other than the rotational speed difference between the first friction surface and the second friction surface used in [a]. Since the characteristic physical quantity has different characteristics in the drive force disconnected state and the drive force connected state, the drive force connected state can be determined by the characteristic physical quantity even when the rotational speed difference approaches zero.

[0020] The clutch switches the driving force transmission path to the driving force connection state after the rotational speed difference approaches zero so as to suppress the synchronization effect, and thus can suppress fluctuations in the driving output until the driving force transmission path is switched to the driving force connection state. Further, in the above-described configuration, since the clutch is a friction clutch that is not a meshing clutch, there is no waiting time for eliminating teeth on teeth, and the connection time does not change depending on the phases of the first friction surface and the second friction surface. Further, since the first friction surface and the second friction surface of the clutch are in surface contact, a good contact state can be obtained before reaching the driving force connection state. Further, the clutch switches the driving force transmission path to the driving force connection state without being maintained in the driving force intermediate connection state after the rotational speed difference is brought close to zero, and thus the time required for switching can be shortened while suppressing variations.

[0021] As described above, it is possible to provide a drive device that can shorten the time required for switching between the series mode in which power generation is performed by the engine while suppressing fluctuations in the driving output and the parallel mode in which driving is performed by the driving force of at least one of the engine or the motor while suppressing variations.

[0022] In addition to the above effects, regarding the synchronization function of the rotational speed and the function of suppressing fluctuations in the driving force, the functional burden on the clutch is reduced by [a] and [b].

[0023] Thereby, the degree of freedom in design such as the selection of the friction material, the required area, the required pressing pressure, and the form such as dry or wet is high, and the miniaturization of the clutch or the degree of freedom in the shape of the clutch can be increased. Therefore, the miniaturization of the drive device or the degree of freedom in the shape can be increased.

[0024] From another aspect, the drive device of the present invention may include the following configuration. The drive device further includes a first rotational speed sensor that detects a physical quantity correlated with the rotational speed of the first friction surface, and a second rotational speed sensor that detects a physical quantity correlated with the rotational speed of the second friction surface. Based on the signals from the first rotational speed sensor and the second rotational speed sensor, the control device controls at least one of the power generation motor or the engine so that the rotational speed difference between the first friction surface and the second friction surface is less than or equal to a target value including zero.

[0025] In the above configuration, based on the signal of the first rotational speed sensor that detects a physical quantity correlated with the rotational speed of the first friction surface and the signal of the second rotational speed sensor that detects a physical quantity correlated with the rotational speed of the second friction surface, the control device can easily and accurately obtain the rotational speed difference between the first friction surface and the second friction surface. Thereby, the control device can accurately control the rotational speed difference to be less than or equal to a target value including zero.

[0026] Therefore, according to the above configuration, the control device can control at least one of the power generation motor or the engine based on the rotational speed difference between the first friction surface and the second friction surface that is easily and accurately obtained. Also, the closer the rotational speed difference is to zero, the more the synchronization effect can be suppressed and the occurrence of the intermediate state can be more suppressed. Further, the closer the rotational speed difference is to zero, the better the connection state can be maintained from the moment the first friction surface and the second friction surface come into contact until the switching to the driving force connection state is completed.

[0027] Thereby, it is possible to realize a drive device that can more accurately suppress fluctuations in drive output while shortening the time required for switching while suppressing variations.

[0028] From another perspective, the drive device of the present invention may include the following configuration. The clutch includes, if the friction clutch is a hydraulic friction clutch operated by hydraulic pressure, a clutch sensor that detects a physical quantity correlated with the operating hydraulic pressure or a physical quantity correlated with the position of the operating member of an actuator that generates the operating hydraulic pressure as the characteristic physical quantity; if the friction clutch is an electromagnetic friction clutch operated by electromagnetic force, a clutch sensor that detects a physical quantity correlated with the electromagnetic force or a physical quantity correlated with the position of the operating member of an actuator that generates the electromagnetic force as the characteristic physical quantity; or if the friction clutch is an electric motor friction clutch operated by an electric motor, a clutch sensor that detects a physical quantity correlated with the operating amount of the electric motor or a physical quantity correlated with the position of the operating member operated by the electric motor as the characteristic physical quantity. Based on the signal from the clutch sensor, the control device controls at least one of the engine or the drive motor to change the driving force that drives the drive output member after the detected characteristic physical quantity becomes a value indicating the drive force connection state.

[0029] In the above configuration, the clutch sensor detects the characteristic physical quantity other than the rotational speed difference between the first friction surface and the second friction surface. The control device then determines whether the drive force is disconnected or connected based on the characteristic physical quantity. Therefore, even when the rotational speed difference between the first and second connection surfaces is zero, the control device can accurately determine whether the drive force transmission path is in a drive force disconnected or drive force connected state based on the characteristic physical quantity detected by the clutch sensor in the friction clutch.

[0030] From another perspective, the drive device of the present invention may include the following configurations. The clutch includes an actuator that changes the relative position of the first friction surface and the second friction surface in the relative direction of movement. The control device operates the actuator with an operation command such that it is not maintained in the intermediate drive force connection state.

[0031] In the above configuration, the clutch actuator is operated by a control device with an operation command that prevents it from being maintained in an intermediate drive force connection state. The operation command that prevents it from being maintained in an intermediate drive force connection state is, for example, an operation command that supplies a current value to the actuator that outputs a force pressing the first friction surface and the second friction surface together so that a friction force is generated between the first friction surface and the second friction surface that does not cause slippage. This makes it possible to realize a drive device that can suppress fluctuations in drive output and shorten the switching time while keeping variations in check.

[0032] From another perspective, the drive device of the present invention may include the following configurations. The clutch includes an electromagnetic actuator as an actuator, which includes an electromagnetic coil that changes the relative position of the first friction surface and the second friction surface in the relative direction of movement. The control device, while the drive device is operating under normal conditions, controls at least one of the power generation motor or engine to reduce the rotational speed difference between the first friction surface and the second friction surface to near zero so that a state in which the first friction surface and the second friction surface are in contact but slipping is suppressed, and then operates the actuator by energizing the electromagnetic coil so that the first friction surface and the second friction surface move from a separated state to a state of contact with little slippage.

[0033] If the clutch is a hydraulic friction clutch, its operation requires a hydraulic pump or hydraulic pathway. When a hydraulic friction clutch operates, there is a delay in the transmission of the driving force as it passes through the hydraulic pump or hydraulic pathway. In the case of a mechanical friction clutch, a means of transmitting the driving force, such as a link or wire, is required. The transmission means of a mechanical friction clutch is not a perfectly rigid body with no deflection whatsoever. Therefore, when a mechanical friction clutch operates, there is a delay in response time due to the deflection.

[0034] In contrast, in the above-described configuration, the relative position of the first and second friction surfaces is changed in the relative movement direction by an electromagnetic actuator. Furthermore, in the electromagnetic actuator, by energizing the electromagnetic coil, the actuator operates without the delay in the transmission of driving force in the hydraulic friction clutch described above, or without the deflection of a mechanical friction clutch.

[0035] Therefore, when operating the clutch, it can switch to a drive force engagement state more quickly compared to a hydraulic friction clutch or a mechanical friction clutch.

[0036] Furthermore, in the above configuration, since the rotational speed difference between the first friction surface and the second friction surface is brought close to zero before contact, the load on the friction material is smaller compared to the case where slippage occurs between the first and second friction surfaces. As a result, there is greater design freedom in the selection of the friction material, the required area, the required pressing pressure, and the type of clutch (dry or wet), which allows for miniaturization of the clutch or increased freedom in the shape of the clutch.

[0037] From another perspective, the drive device of the present invention may include the following configurations. The clutch is a single-plate type composed of a pair of rotating bodies in which the relative position of the first friction surface and the second friction surface in the axial direction changes, and the friction material is a dry friction material that does not require oil lubrication. While the drive device is operating in a normal state, the control device controls at least one of the power generation motor or the engine to reduce the rotational speed difference of the dry friction material to near zero so that the state in which the dry friction material is in contact but slipping is suppressed, and then operates the clutch so that the dry friction material moves from a separated state to a contact state with little slippage.

[0038] In the above configuration, a dry friction material is provided on the first and second friction surfaces of the clutch. Therefore, in the above configuration, there is no drag caused by oil compared to a wet clutch. As a result, the gap in the relative displacement direction between the first and second friction surfaces can be reduced. This shortens the time it takes to reach a state of drive force connection when the clutch is operated. Furthermore, in the case of a multi-plate clutch that includes multiple clutch plates as friction material, it is necessary to consider variations in the thickness of each clutch plate. Therefore, in a multi-plate clutch, the clutch stroke needs to be increased to accommodate variations in the thickness of each clutch plate. In the above configuration, a single-plate clutch allows for a smaller stroke compared to a multi-plate clutch. This shortens the time it takes to reach a state of drive force connection when the clutch is operated.

[0039] The technical terms used herein are for the purpose of defining only specific embodiments and are not intended to limit the invention.

[0040] As used herein, "and / or" includes all combinations of one or more relatedly listed components.

[0041] In this specification, the use of “including,” “comprising,” or “having,” and variations thereof, identifies the presence of described features, processes, operations, elements, components, and / or equivalents thereof, but may include one or more of the steps, operations, elements, components, and / or groups thereof.

[0042] In this specification, “attached,” “connected,” “joined,” and / or their equivalents are used in a broad sense and include both “direct and indirect” attachments, connections, and combinations. Furthermore, “connected” and “joined” are not limited to physical or mechanical connections or combinations, but may include direct or indirect electrical connections or combinations.

[0043] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meanings as those generally understood by those skilled in the art to which this invention pertains.

[0044] Terms as defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology and this disclosure, and not as ideal or overly formal unless expressly defined herein.

[0045] It is understood that several techniques and processes are disclosed in this description of the present invention. Each of these has its own individual benefit and may be used in conjunction with one or more, or possibly all, of the other disclosed techniques.

[0046] Therefore, for clarity, the description of this invention refrains from unnecessarily repeating all possible combinations of the individual steps. However, this specification and the claims should be read with the understanding that all such combinations are within the scope of the invention.

[0047] This specification describes embodiments of the drive device according to the present invention.

[0048] The following description includes numerous specific examples to provide a complete understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be carried out without these specific examples.

[0049] Therefore, the following disclosure should be considered illustrative of the present invention and is not intended to limit the present invention to any specific embodiment shown in the following drawings or description.

[0050] [Hybrid drive system] In this specification, a hybrid drive system refers to a powertrain that uses both an internal combustion engine and an electric motor as power sources. Hybrid drive systems include, for example, parallel systems and series systems. In a parallel system, both the engine and the motor are used to drive drive output members such as the wheels of the vehicle. In a series system, the engine is used only to drive a generator motor, and the wheels and other components are driven by a drive motor powered by electricity generated by the generator motor. There are also systems in which the vehicle operates by switching between multiple driving modes, such as a mode driven by the parallel system or a mode driven by the series system.

[0051] [Drive output component] In this specification, a drive output member means a member to which power from a power source such as an engine or motor is transmitted as driving force. A drive output member is, for example, a shaft that outputs driving force to a drive wheel.

[0052] [Drive force transmission path] In this specification, the term "drive force transmission path" refers to the path through which power from the engine is transmitted to the drive output member. The drive force transmission path is switched between a drive force disconnected state and a drive force connected state by a clutch. The drive force disconnected state is a state in which power from the engine is not transmitted to the drive output member. The drive force connected state is a state in which power from the engine is transmitted to the drive output member.

[0053] [Physical quantities correlated with the rotational speed of the clutch friction surface] In this specification, a physical quantity correlated with the rotational speed of the clutch friction surface means a physical quantity related to the rotational motion of the friction surface, such as the angular velocity of the friction surface's rotation, the number of rotations per unit time, the rate of change in time at a unit angular position, or the rate of change in angular velocity per unit time.

[0054] [Physical quantities correlated with hydraulic pressure] In this specification, a physical quantity correlated with hydraulic pressure means a physical quantity related to hydraulic-based actions or operations, such as hydraulic pressure or stress generated in the hydraulic pipe through which the hydraulic fluid flows when a hydraulic actuator is operated, the amount of oil supplied, the supply time, the opening and closing of a valve, the speed of movement, the force, or the strain.

[0055] [Physical quantities correlated with electromagnetic force] In this specification, a physical quantity correlated with electromagnetic force means a physical quantity related to an action or operation based on electromagnetic force, such as voltage or current when an electromagnetic actuator is operated, magnitude of the electromagnetic force, velocity of movement due to electromagnetic force, attractive force, or strain.

[0056] [Physical quantities correlated with the operating amount of an electric motor] In this specification, a physical quantity correlated with the working amount of an electric motor means a physical quantity related to the motor's action or operation, such as the cumulative value of the motor's rotational position or rotational angular velocity, the supplied power, torque, or acceleration.

[0057] [Saddle-type vehicle] In this specification, a saddle-type vehicle is a vehicle in which the occupant sits on the seat while straddling it. Therefore, a saddle-type vehicle includes not only two-wheeled vehicles but also three-wheeled and four-wheeled vehicles, as long as the occupant sits on the seat while straddling it.

[0058] [Friction clutch] In this specification, a friction clutch means a clutch that transmits driving force from one friction surface to the other by frictional force generated when a first friction surface and a second friction surface, each provided with a friction material, are pressed against each other and brought into contact.

[0059] [Conformity effect] In this specification, the synchronization effect refers to the effect that occurs when the first and second friction surfaces of a clutch are brought closer together to a state in which they are in contact but sliding, resulting in the rotational speeds of the first and second friction surfaces approaching each other's rotational speeds between the rotational speeds of the first and second friction surfaces before contact, due to frictional contact, and thus reducing the rotational difference between them.

[0060] [Physical quantities other than rotational speed difference] In this specification, physical quantities other than rotational speed difference mean physical quantities including, for example, at least one of the physical quantities relating to the axial or radial relative position of the first friction surface and the second friction surface, the pressing pressure or force between the first friction surface and the second friction surface, and the physical quantities relating to the actuator that presses the first friction surface and the second friction surface together.

[0061] [Characteristic physical quantity] In this specification, a characteristic physical quantity means a physical quantity that has different characteristics in the driving force disconnected state and the driving force connected state. Therefore, the characteristic physical quantity can be used to determine the clutch connection state. The characteristic physical quantity is, for example, a physical quantity other than the rotational speed difference between the first friction surface and the second friction surface. Furthermore, the characteristic physical quantity is a physical quantity that includes, for example, at least one of a physical quantity related to the axial or radial relative position of the first friction surface and the second friction surface, the pressing pressure or force between the first friction surface and the second friction surface, and a physical quantity related to the actuator that presses the first friction surface and the second friction surface together.

[0062] [Transmitted driving force in a power-driven state] In this specification, the transmitted driving force in the driving force connection state means the driving force output from the engine to the drive output member via the driving force transmission path when the driving force transmission path is in the driving force connection state, that is, when a frictional force is generated between the first friction surface and the second friction surface by the force pressing the first friction surface and the second friction surface together, so that no slippage occurs. [Effects of the Invention]

[0063] According to one embodiment of the present invention, a drive device can be realized that can reduce the time required to switch between a series mode, in which power generation is performed by an engine, and a parallel mode, in which the device is driven by the driving force of at least one of the engine or motor, while suppressing fluctuations in the drive output, and reducing variations in this time. [Brief explanation of the drawing]

[0064] [Figure 1] Figure 1 is a schematic diagram showing the general configuration of the drive device according to Embodiment 1. [Figure 2] Figure 2 is a schematic diagram illustrating the power transmission path in series mode. [Figure 3] Figure 3 is a schematic diagram illustrating the transmission path of the driving force in parallel mode. [Figure 4] Figure 4 is an external view showing a schematic configuration of a vehicle having a drive system according to Embodiment 2. [Figure 5] Figure 5 is a schematic cross-sectional view showing the general configuration of the drive unit. [Figure 6] Figure 6 is a flowchart illustrating the details of the control system. [Figure 7] Figure 7 is a graph showing the details of the control system. [Figure 8] Figure 8 is a schematic diagram illustrating the transmission path of the driving force in parallel mode for driving a power generation motor. [Figure 9] Figure 9 is a schematic diagram illustrating the regenerative mode. [Modes for carrying out the invention]

[0065] The embodiments will be described below with reference to the drawings. In each drawing, the same parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component.

[0066] In the following diagrams, arrow FR indicates the front of vehicle 100 in the longitudinal direction. Arrow RR indicates the rear of vehicle 100 in the longitudinal direction. Arrow LF indicates the left of vehicle 100 in the lateral direction. Arrow RG indicates the right of vehicle 100 in the lateral direction. Arrow UP indicates the upward direction of vehicle 100 in the vertical direction. Arrow DW indicates the downward direction of vehicle 100 in the vertical direction. Furthermore, in the following explanation, the vertical direction, lateral direction, and longitudinal direction refer to the vertical direction, lateral direction, and longitudinal direction, respectively, as viewed from the perspective of the driver operating vehicle 100.

[0067] <Embodiment 1> (Schematic configuration) Figure 1 is a schematic diagram showing the general configuration of the drive unit 1 according to Embodiment 1. Referring to Figure 1, the drive unit 1 is a hybrid system configured to switch between series mode MODE_S and parallel mode MODE_P. The series mode MODE_S and parallel mode MODE_P driving modes will be described in detail later.

[0068] The drive unit 1, although not specifically shown, is mounted on a mobile body or machine, for example, as a power source. The mobile body includes, for example, unmanned aircraft or vehicles that move on land, in the air, on water, or underwater. The mobile body includes, for example, vehicles, motorcycles, cars, ATVs (all-terrain vehicles), ROVs (Recreational Off-highway Vehicles), flying vehicles, various drones, or water vehicles.

[0069] The drive unit 1 comprises an engine 10, a power generation motor MG1, a battery 20, a drive output member 30, a drive motor MG2, a clutch 40, a power transmission member 50, and a control device 60.

[0070] The engine 10 generates power by burning fuel. The engine 10 includes a piston 11 and a crankshaft 12. The linear motion of the piston 11 produced by combustion is converted into rotational motion by the crankshaft 12. The crankshaft 12 has a first output unit 121 that outputs the driving force from the rotation to the power generation motor MG1, and a second output unit 122 that outputs the driving force from the rotation to the clutch 40.

[0071] The power generation motor MG1 functions as a generator when driven by the engine 10. The power generation motor MG1 is electrically connected to the battery 20 (described later) by connecting wiring 21. The power generation motor MG1 transmits the electricity generated by being driven by the engine 10 to the battery 20 via the connecting wiring 21. The power generation motor MG1 may also assist the driving force of the engine 10 by using the electricity supplied from the battery 20 via the connecting wiring 21 to rotate.

[0072] Battery 20 is a rechargeable battery that can be repeatedly charged and discharged. Battery 20 is electrically connected to the generator motor MG1 and the drive motor MG2 by connecting wiring 21. Battery 20 is charged by the power generated by the generator motor MG1. Battery 20 also supplies power to the drive motor MG2, which will be described later. In addition, battery 20 is charged by regenerative power generated by the drive motor MG2.

[0073] The drive output member 30 is a member to which power from at least one of the engine 10 or the drive motor MG2 is transmitted as driving force by the power transmission member 50, which will be described later. The drive output member 30 is, for example, a shaft that outputs driving force to the drive wheel TR1. Note that the member to which the drive output member 30 outputs driving force is not limited to tires or wheels. The drive output member 30 may output driving force to a driven member such as a propeller or impeller. Furthermore, the drive output member 30 may be the drive wheel itself.

[0074] The drive motor MG2 is rotationally driven by power supplied from at least the battery 20 via the connecting wiring 21. The drive motor MG2 transmits rotational force to the drive output member 30 by the power transmission member 50 described later. The drive motor MG2 can also be rotationally driven by power generated by the power generation motor MG1. As described above, the drive motor MG2 also functions as a generator. The drive motor MG2 generates regenerative power, for example, by the rotational force of the drive wheel TR1.

[0075] The clutch 40 is provided in the drive force transmission path PT1 between the drive output member 30 and the engine 10. The clutch 40 switches the drive force transmission path PT1 between a drive force disconnection state and a drive force connection state.

[0076] The power transmission path PT1 refers to the path through which power from the engine 10 is transmitted to the drive output member 30. In addition to the clutch 40, the power transmission path PT1 may further include one or more mechanical elements. For example, the power transmission path PT1 may further include mechanical elements such as gears, rollers, shafts, pulleys, wires, belts, sprockets, chains, linkage mechanisms, differentials, or speed reducers, or combinations thereof.

[0077] The clutch 40 is a friction clutch that is not a meshing clutch. The friction clutch may be dry or wet. The friction clutch may be single-plate or multi-plate. The friction clutch may be, for example, a hydraulic friction clutch operated by hydraulic pressure, an electromagnetic friction clutch operated by electromagnetic force, or an electric motor friction clutch operated by an electric motor. The friction clutch may also be a pneumatic friction clutch or a mechanical friction clutch.

[0078] The clutch 40 has a first friction surface 41 and a second friction surface 42, each provided with a friction material. The first friction surface 41 and the second friction surface 42 are configured to be rotatable about the rotation axis P1.

[0079] The first friction surface 41 and the second friction surface 42 are positioned side by side in the relative movement direction MV, which is the axial direction of the rotation axis P1 of the first friction surface 41 and the second friction surface 42.

[0080] The first friction surface 41 rotates around the rotation axis P1 by the driving force from the second output unit 122 of the engine 10, even when the first friction surface 41 and the second friction surface 42 are separated in the relative direction of movement MV. When the first friction surface 41 and the second friction surface 42 come into frictional contact as they move toward each other in the relative direction of movement MV, power is transmitted from the first friction surface 41, which is rotating by the driving force of the engine 10, to the second friction surface 42. As a result, the second friction surface 42 rotates around the rotation axis P1.

[0081] Furthermore, the first friction surface 41 and the second friction surface 42 may be aligned in the radial direction of their rotation axis P1, and may also move relative to each other in the radial direction of the rotation axis P1. In addition, when the first friction surface 41 and the second friction surface 42 approach each other and come into frictional contact due to relative movement in the radial direction, power is transmitted from the first friction surface 41 to the second friction surface 42.

[0082] The clutch 40 transmits the driving force of the engine 10 to the driving force transmission path PT1 when the driving force transmission path PT1 switches from a driving force disconnected state to a driving force connected state. In other words, the clutch 40 transmits the driving force of the engine 10 to the driving force transmission path PT1 when the clutch 40 switches from a disengaged state to a connected state.

[0083] The aforementioned drive force disconnection state is a state in which the first friction surface 41 and the second friction surface 42 are separated from each other in the relative movement direction MV, and therefore drive force is not transmitted from the first friction surface 41 to the second friction surface 42. This state in which drive force is not transmitted from the first friction surface 41 to the second friction surface 42 is also called the state in which the clutch 40 is disengaged. In other words, when the clutch 40 is disengaged, the drive force transmission path PT1 enters the aforementioned drive force disconnection state. In series mode MODE_S, the drive force transmission path PT1 is in the aforementioned drive force disconnection state.

[0084] The aforementioned driving force connection state is a state in which the first friction surface 41 and the second friction surface 42 are moved relative to each other in the relative movement direction MV and come into frictional contact, thereby transmitting driving force from the first friction surface 41 to the second friction surface 42. This state in which driving force is transmitted from the first friction surface 41 to the second friction surface 42 is also called the state in which the clutch 40 is engaged. In other words, when the clutch 40 is engaged, the driving force transmission path PT1 enters the aforementioned driving force connection state. In parallel mode MODE_P, the driving force transmission path PT1 is in the aforementioned driving force connection state.

[0085] A characteristic physical quantity Prm, which is a physical quantity other than the rotational speed difference between the first friction surface 41 and the second friction surface 42, has different characteristics in the driving force disconnected state and the driving force connected state. The characteristic physical quantity Prm includes at least one physical quantity related to the relative position of the first friction surface 41 and the second friction surface 42, and a physical quantity related to the pressing pressure or current between the first friction surface 41 and the second friction surface 42. For example, in the driving force disconnected state, the characteristic physical quantity Prm is a value Prm1 below a certain threshold. On the other hand, for example, in the driving force connected state, the characteristic physical quantity Prm is a value Prm2 above a certain threshold.

[0086] The power transmission member 50 transmits the input power to an output position located away from the input position and outputs it. The power transmission member 50 is provided in the drive force transmission path PT1. From another perspective, the clutch 40 and the power transmission member 50 constitute at least a part of the drive force transmission path PT1. The power transmission member 50 is composed of, for example, a reduction gear.

[0087] The power transmission member 50 transmits power from the drive motor MG2 as driving force to the drive output member 30 when the drive force transmission path PT1 is in a drive force disconnected state because the clutch 40 is disengaged. When the drive force transmission path PT1 is in a drive force connected state because the clutch 40 is engaged, the power transmission member 50 combines the power from the engine 10 transmitted via the clutch 40 with the power from the drive motor MG2 and transmits it as driving force to the drive output member 30. The power transmission member 50 can also transmit only the power from the clutch 40 as driving force to the drive output member 30 when the drive force transmission path PT1 is in a drive force connected state.

[0088] The control device 60 controls the engine 10, the generator motor MG1, the drive motor MG2, and the clutch 40. The control device 60 may include various control units such as a VCU (Vehicle Control Unit), GCU (General Control Unit or Generator Control Unit), BMU (Battery Management Unit), TCU (Transmission Control Unit), or MCU (Motor Control Unit), and combinations of multiple such control units. The control device 60 includes a microcontroller, CPU (Central Processing Unit), GPU (Graphics Processing Unit), microprocessor, multiprocessor, application-specific integrated circuit (ASIC), programmable logic circuit (PLC), field-programmable gate array (FPGA), or any other arithmetic unit or logic circuit capable of performing the processing described herein.

[0089] The control device 60 may include memory for temporarily or permanently storing programs or data for causing the arithmetic unit to execute various processes.

[0090] (Switching of driving modes by the control device) The control device 60, for example, switches the driving mode of the drive unit 1 from series mode MODE_S to parallel mode MODE_P. Figure 2 is a schematic diagram illustrating the power transmission path in series mode MODE_S. Figure 3 is a schematic diagram illustrating the power transmission path in parallel mode MODE_P.

[0091] Referring to Figure 2, series mode MODE_S is a driving mode in which, when the drive force transmission path PT1 by the clutch 40 is disconnected, the generator motor MG1, which is driven by the drive force of the engine 10, generates electricity.

[0092] Referring to Figure 3, parallel mode MODE_P is a driving mode in which, for example, in the state of drive force connection of the drive force transmission path PT1 by the clutch 40, the drive output member 30 is driven by at least one of the drive forces of the engine 10 and the drive motor MG2. In parallel mode MODE_P as well, the power generation motor MG1 is driven by the drive force of the engine 10.

[0093] Figure 9 is a schematic diagram illustrating the regenerative mode. Whether operating in series mode MODE_S or parallel mode MODE_P, as shown in Figure 9, the drive motor MG2 generates regenerative power when, for example, during deceleration, the rotational force of the drive wheel TR1 is transmitted through the drive force transmission path PT1, and outputs the regenerative power to the battery 20. In the regenerative mode shown in Figure 9, the power generation motor MG1 may be powered by the driving force of the engine 10.

[0094] Furthermore, the control device 60 may stop the power generation motor MG1 when power generation is not required, regardless of whether it is operating in series mode MODE_S or parallel mode MODE_P.

[0095] Furthermore, the control device 60 may drive the power generation motor MG1 in parallel mode MODE_P. Figure 8 is a schematic diagram illustrating the transmission path of the driving force in parallel mode MODE_P_TB when the power generation motor MG1 is driven.

[0096] Referring to Figure 8, in parallel mode MODE_P_TB, the control device 60 drives the drive output member 30 with at least one of the driving forces of the engine 10 and the power generator motor MG1 and the driving force of the drive motor MG2, in the state of drive force connection of the drive force transmission path PT1 by the clutch 40.

[0097] Furthermore, when switching from series mode MODE_S to a driving mode, the system may gradually switch from parallel mode MODE_P, in which the drive output member 30 is driven by at least one of the driving forces of the engine 10 and the drive motor MG2, to parallel mode MODE_P_TB, in which the power generation motor MG1 is driven.

[0098] Furthermore, when switching between driving modes, it may be possible to switch between series mode MODE_S and parallel mode MODE_P, in which the drive output member 30 is driven by at least one of the driving forces of the engine 10 and the drive motor MG2, and parallel mode MODE_P_TB, in which the power generation motor MG1 is driven.

[0099] In the following description, unless otherwise specified, parallel mode MODE_P includes parallel mode MODE_P_TB, which drives the generator motor MG1.

[0100] When the drive unit 1 is operating in a normal state, the control device 60 performs the following controls [a] and [b] when it switches from series mode MODE_S to parallel mode MODE_P. [a] First, the control device 60 controls at least one of the engine 10 or the power generator motor MG1 so as to suppress the rotational speed synchronization effect due to frictional contact between the first friction surface 41 and the second friction surface 42 when the clutch 40 is operated, thereby bringing the rotational speed difference between the first friction surface 41 and the second friction surface 42 close to zero when the drive force transmission path PT1 by the clutch 40 is disconnected. [b] Next, the control device 60 operates the clutch 40 so as not to maintain an intermediate drive force connection state in which the clutch 40 transmits a drive force lower than the drive force transmitted in the drive force connection state. That is, the control device 60 operates the clutch 40 without going through an intermediate connection state (so-called half-clutch state) in which the first friction surface 41 and the second friction surface 42 are in contact but slipping. Then, after the characteristic physical quantity Prm becomes the value Prm2 which indicates the drive force connection state, the control device 60 starts parallel mode MODE_P. In parallel mode MODE_P, the control device 60 controls at least one of the engine 10 or the drive motor MG2 to change the drive force that drives the drive output member 30.

[0101] In the above configuration, when the control device 60 switches the driving mode from series mode MODE_S to parallel mode MODE_P, the engine 10 is not affected by the drive output member 30 because the drive force transmission path PT1 is in a state of drive force disconnection. Furthermore, in the above configuration, the power generation motor MG1 can be electrically controlled with good responsiveness by the control device 60.

[0102] The control device 60 controls the engine 10 or the generator motor MG1 so that the rotational speed difference between the first friction surface 41 and the second friction surface 42 when the clutch 40 is operating approaches zero in order to suppress the rotational speed synchronization effect.

[0103] Furthermore, the control device 60 controls the clutch 40 to move from a drive force disconnected state to a drive force connected state without maintaining it in an intermediate drive force connected state.

[0104] In this way, the drive unit 1 transmits the driving force of the engine 10 to the drive output member 30 while the rotational speed difference between the first friction surface 41 on the first output unit 121 side and the second friction surface 42 on the drive output member 30 side is brought close to zero. Therefore, fluctuations in the rotational speed of the drive output member 30 when the drive from the engine 10 is transmitted to the drive output member 30, which is driven by the drive motor MG2, can be suppressed. Furthermore, since the drive unit 1 does not have to wait for the synchronization effect between the rotational speed of the first friction surface 41 on the second output unit 122 side and the rotational speed of the second friction surface 42 on the drive output member 30 side, or the waiting time is substantially zero, the driving force can be transmitted from the first friction surface 41 to the second friction surface 42 in a shorter time and with less loss compared to the case where the first friction surface 41 and the second friction surface 42 are connected via an intermediate driving force connection state in which they contact each other while rotating at different rotational speeds.

[0105] Furthermore, after the rotational speed difference approaches zero, the control device 60 activates a friction clutch, which is not a meshing clutch, to move from the drive force disconnected state to the drive force connected state without maintaining the drive force intermediate connected state. The control device 60 determines whether the drive force transmission path PT1 has entered the drive force connected state by a characteristic physical quantity Prm, which is other than the rotational speed difference between the first friction surface 41 and the second friction surface 42 used in [a]. Since the characteristic physical quantity Prm has different characteristics in the drive force disconnected state and the drive force connected state, the drive force connected state can be determined by the characteristic physical quantity Prm even when the rotational speed difference approaches zero.

[0106] The clutch 40 switches the drive force transmission path to the drive force connected state after the rotational speed difference approaches zero, so that the synchronization effect is suppressed, thereby suppressing fluctuations in the drive output until the drive force transmission path PT1 switches to the drive force connected state. Furthermore, in the above configuration, since the clutch 40 is a friction clutch and not a meshing clutch, there is no waiting time for teeth-on-teeth to dissipate, and the connection time does not change depending on the phase of the first friction surface 41 and the second friction surface 42. In addition, a good contact state is obtained before the drive force connected state is reached because the first friction surface 41 and the second friction surface 42 of the clutch 40 are in surface contact. Moreover, since the clutch 40 switches to the drive force connected state without being maintained in the intermediate drive force connected state after the rotational speed difference approaches zero, the time required for switching can be shortened while suppressing variability.

[0107] As described above, a drive device 1 can be provided that can shorten the time required to switch between a series mode MODE_S, in which power generation is performed by the engine 10, and a parallel mode MODE_P, in which the drive is performed by the driving force of at least one of the engine 10 or the drive motor MG2, while suppressing fluctuations in the drive output, and while minimizing variations.

[0108] Furthermore, in addition to the effects described above, the functional load on the friction clutch is reduced by [a] and [b] with respect to the function of synchronizing rotational speed and suppressing fluctuations in driving force.

[0109] This allows for greater design freedom in terms of friction material selection, required area, required pressing pressure, and type (dry or wet), enabling miniaturization of the friction clutch or increased freedom in its shape. Consequently, the drive unit 1 can be miniaturized or its shape can be made more flexible.

[0110] <Embodiment 2> (Schematic configuration) Figure 4 is an external view showing the schematic configuration of a vehicle 100 having a drive unit 2 according to Embodiment 2. Figure 5 is a schematic cross-sectional view showing the schematic configuration of the drive unit 2. The drive unit 2 according to Embodiment 2 is configured as a powertrain that drives the drive wheels TR1 of the vehicle 100. In the following, components identical to those in Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted, and only the parts that differ from Embodiment 1 will be described.

[0111] Referring to Figure 4, the two-wheeled vehicle 100 has a drive unit 2 that drives the drive wheel TR1, which is the rear wheel of the vehicle 100. The vehicle 100 is a saddle-type vehicle. Referring to Figure 5, the drive unit 2 comprises an engine 10, a power generator motor MG1, a battery 20, a drive output member 30, a drive motor MG2, a clutch 401, a power transmission member 50, a control device 60, a first rotational speed sensor SN11, a second rotational speed sensor SN12, a centrifugal fan 71, and a radiator 72.

[0112] The first output section 121 and the second output section 122 of the engine 10 rotate around a rotation axis P1 that extends in the left-right direction of the vehicle 100. The first output section 121 extends to one side of the rotation axis P1. The second output section 122 extends to the other side of the rotation axis P1.

[0113] The clutch 401 is an electromagnetic friction clutch that operates by electromagnetic force. The clutch 401 includes a first friction surface 41, a second friction surface 42, an actuator 43, a clutch sensor 44, and a first pulley 45.

[0114] The first friction surface 41 and the second friction surface 42 of the clutch 401 are each provided with a dry friction material that does not require oil lubrication. The first friction surface 41 and the second friction surface 42 of the clutch 401 rotate around the rotation axis P1 in conjunction with the rotation of the second output unit 122. The first friction surface 41 and the second friction surface 42 move relative to each other in the axial direction of the rotation axis P1. That is, the direction MV of relative movement between the first friction surface 41 and the second friction surface 42 is the axial direction of the rotation axis P1. The clutch 401 is a single-plate type composed of a pair of rotating bodies in which the relative position of the first friction surface 41 and the second friction surface 42 in the axial direction changes.

[0115] Actuator 43 is an electromagnetic actuator that includes an electromagnetic coil. Actuator 43 changes the relative position of the first friction surface 41 and the second friction surface 42 in the relative movement direction MV in response to the input excitation current.

[0116] The clutch sensor 44 detects a physical quantity correlated with the electromagnetic force, or a physical quantity correlated with the position of the operating member of the actuator 43 that generates the electromagnetic force, as a characteristic physical quantity Prm. The clutch sensor 44 is, for example, a current sensor that detects the excitation current as a characteristic physical quantity Prm.

[0117] The first pulley 45 rotates around the rotation axis P1 by frictional contact between the first friction surface 41 and the second friction surface 42 as they move toward each other in the relative movement direction MV. The first pulley 45 is configured to transmit rotational power to the power transmission member 50, which will be described below.

[0118] The power transmission member 50 includes a cog belt 51, a second pulley 52, and a reduction gear 53. The cog belt 51 transmits the rotational force of the first pulley 45 of the clutch 401 to the second pulley 52. ​​The second pulley 52 inputs the rotational force transmitted from the first pulley 45 to the input shaft of the reduction gear 53. The reduction gear 53 has an input shaft to which the rotational force of the first pulley 45 is input, an input shaft to which the rotational force of the drive motor MG2 is input, and an output shaft that outputs torque to the drive output member 30. The two input shafts may have a double structure. The reduction gear 53 combines the rotational force of the first pulley 45 and the rotational force of the drive motor MG2 and outputs a torque proportional to the reduction ratio to the drive output member 30.

[0119] The first rotational speed sensor SN11 detects the rotational speed of the power generation motor MG1 and outputs a signal indicating the detected rotational speed to the control device 60. The power generation motor MG1 rotates around the rotation axis P1 in conjunction with the rotation of the first output unit 121. In addition, the first friction surface 41 of the clutch 401 rotates around the rotation axis P1 in conjunction with the rotation of the second output unit 122.

[0120] Therefore, the rotational speed of the power generation motor MG1 detected by the first rotational speed sensor SN11 is also the rotational speed of the first friction surface 41 of the clutch 401. Thus, the first rotational speed sensor SN11 is a sensor that detects a physical quantity correlated with the rotational speed of the first friction surface 41.

[0121] The second rotational speed sensor SN12 detects the rotational speed of the drive motor MG2 and outputs a signal indicating the detected rotational speed to the control device 60. In series mode MODE_S, the rotational force of the drive motor MG2 is transmitted to the first pulley 45 of the clutch 401 via the reduction gear 53, second pulley 52, and cog belt 51 of the power transmission member 50. The second friction surface 42 rotates in conjunction with the rotation of the first pulley 45.

[0122] Therefore, the rotational speed of the second friction surface 42 of the clutch 401 can be determined based on the rotational speed of the drive motor MG2 detected by the second rotational speed sensor SN12 and the reduction ratio, etc. Thus, the second rotational speed sensor SN12 is a sensor that detects a physical quantity correlated with the rotational speed of the second friction surface 42.

[0123] The control device 60 operates the actuator 43 with an operation command that prevents it from being maintained in an intermediate drive force connection state. Details of the control by the control device 60 will be described later.

[0124] The centrifugal fan 71 is located on the other side of the clutch 401 on the rotation axis P1. The centrifugal fan 71 is supported by the second output unit 122 so as to be rotatable about the rotation axis P1 by the rotation of the second output unit 122.

[0125] The radiator 72 is located to the right of the centrifugal fan 71. The radiator 72 is cooled by the centrifugal fan 71.

[0126] (Regarding control by control devices) Figure 6 is a flowchart showing the details of the control by the control device 60. Figure 7 is a graph showing the details of the control by the control device 60.

[0127] Referring to Figures 5, 6, and 7, the switching control method S1 when the control device 60 switches the driving mode from series mode MODE_S to parallel mode MODE_P will be described.

[0128] The switching control method S1 is executed when a switching request is made to switch the driving mode from series mode MODE_S to parallel mode MODE_P. The switching request may be made automatically depending on the driving conditions, or it may be made manually by the driver of vehicle 100.

[0129] Furthermore, as described above, the parallel mode MODE_P includes not only a driving mode in which the drive output member 30 is driven by at least one of the drive forces of the engine 10 and the drive motor MG2 in the drive force connection state of the drive force transmission path PT1, but also a parallel mode MODE_P_TB in which the power generation motor MG1 is driven.

[0130] The parallel mode MODE_P_TB for driving the generator motor MG1 may be automatically switched according to the driving conditions of the vehicle 100, such as the throttle opening or the rotational speed of the engine 10, or it may be manually switched according to the driver's input operation to the vehicle 100. The input operation may be performed, for example, by a physical switch provided on the vehicle 100 or by a touch panel provided on the vehicle 100. Furthermore, the parallel mode MODE_P_TB for driving the generator motor MG1 may be restricted when the charge level of the battery 20 falls below a certain level. In addition, the parallel mode MODE_P_TB for driving the generator motor MG1 may be enabled or disabled by a setting operation on the vehicle 100.

[0131] Figure 7 shows graph Grph1 of the driving mode, graph Grph2 of the rotational speed of clutch 401, and graph Grph3 of the excitation current of clutch 401.

[0132] When a switching request is made in series mode MODE_S, the driving mode switches to switching mode MODE_C, in which switching control method S1 is executed. When the execution of switching control method S1 is completed, the driving mode switches from switching mode MODE_C to parallel mode MODE_P. The horizontal axis in each graph represents time (t). The level of the curve Hv_MD shown in the driving mode graph Grph1 represents the driving mode. The rotational speed graph Grph2 of the clutch 401 shows the rotational speed Rev_EG of the first friction surface 41 and the rotational speed Rev_DM of the second friction surface 42 at each time point. The excitation current graph Grph3 of the clutch 401 shows the excitation current value C_Curr at each time point.

[0133] The flow of the switching control method S1 will be explained according to the flowchart shown in Figure 6. The switching control method S1 is started when a switching request is made in series mode MODE_S (step S in Figure 6, t=TP11 in Figure 7). When the driving mode is switched to switching mode MODE_C by the switching request, the control device 60 synchronizes the rotational speed of the first friction surface 41 (Rev_EG) and the rotational speed of the second friction surface 42 (Rev_DM) (step S11). In detail, the control device 60 controls at least one of the power generation motor MG1 or the engine 10 based on the signals from the first rotational speed sensor SN11 and the second rotational speed sensor SN12 until the rotational speed difference between the first friction surface 41 and the second friction surface 42 is less than or equal to a target value N1, which includes zero (while "N" is displayed in step S12).

[0134] While the drive unit 2 is operating normally, the control device 60 controls at least one of the power generation motor MG1 or the engine 10 to reduce the rotational speed difference between the first friction surface 41 and the second friction surface 42, which are provided with dry friction material, to near zero (in step S12, "Y", t=TP12 in Figure 7), and then operates the actuator 43 by energizing the electromagnetic coil so that the first friction surface 41 and the second friction surface 42 move from a separated state to a contact state with less slippage (step S13). In other words, the control device 60 operates the actuator 43 with an operation command that does not maintain the intermediate connection state of the driving force.

[0135] The control device 60 controls the excitation current value C_Curr supplied to the actuator 43 so that it increases to the target value Tg1. As a result, the excitation current value C_Curr increases from 0. After that, the excitation current value C_Curr begins to increase again after passing through a downward point VP1.

[0136] The control device 60 determines the excitation current value C_Curr as a characteristic physical quantity Prm (step S14). If the excitation current value C_Curr is smaller than the threshold Th1 ("N" in step S14), the control device 60 performs control to increase the excitation current value C_Curr.

[0137] When the excitation current value C_Curr is greater than or equal to the threshold Th1 (when it reaches "Y" in step S14, or t=TP13 in Figure 7), the control device 60 determines that the switching control is complete. That is, the control device 60 determines that the drive force transmission path PT1 is in a drive force connected state. The control device 60 switches the driving mode from switching mode MODE_C to parallel mode MODE_P (step S15). With this, the switching control method S1 is completed (step E).

[0138] Subsequently, in parallel mode MODE_P, the control device 60 controls at least one of the engine 10 or the drive motor MG2 to change the driving force that drives the drive output member 30.

[0139] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely illustrative examples for carrying out the present invention. Therefore, the present invention is not limited to the embodiments described above, and it is possible to carry out the present invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0140] Although not specifically described in the above embodiments, the control device may switch the driving mode to a battery driving mode in which only the driving force of the drive motor is output to the drive output member. Alternatively, the control device may switch the driving mode to an engine driving mode in which only the driving force of the engine is output to the drive output member.

[0141] In each of the above embodiments, in parallel mode MODE_P_TB, where the power generation motor MG1 is driven, the driving force of the engine 10 is assisted by the driving force of the power generation motor MG1. However, in parallel mode, the drive motor may also be assisted by the driving force of another drive source.

[0142] In the above embodiment 2, the drive unit 2 includes a centrifugal fan 71 and a radiator 72. The centrifugal fan 71 and the radiator 72 are located to the right of the engine 10. However, the centrifugal fan and the radiator may be located in different positions. The drive unit may not have at least one of the centrifugal fan and the radiator.

[0143] In the above embodiment 2, the clutch 401 includes a dry friction material and is of a single-plate type. However, the clutch may also include a wet friction material. Furthermore, the clutch may be of a multi-plate type.

[0144] In the second embodiment described above, the clutch sensor 44 detects a physical quantity correlated with the electromagnetic force, or a physical quantity correlated with the position of the operating member of the actuator 43 that generates the electromagnetic force, as a characteristic physical quantity Prm. The clutch sensor 44 is, for example, a current sensor that detects the excitation current as a characteristic physical quantity Prm. However, the clutch sensor may also be a torque sensor that detects the torque transmitted from the first friction surface to the second friction surface.

[0145] Furthermore, if the clutch is a hydraulic friction clutch operated by hydraulic pressure, it may include a clutch sensor that detects a physical quantity correlated with the operating hydraulic pressure, or a physical quantity correlated with the position of the operating member of the actuator that generates the operating hydraulic pressure, as the characteristic physical quantity. Furthermore, if the clutch is an electric motor type friction clutch operated by an electric motor, it may include a clutch sensor that detects a physical quantity correlated with the amount of operation of the electric motor, or a physical quantity correlated with the position of the operating member operated by the electric motor, as the characteristic physical quantity.

[0146] In the above embodiment 2, the control device 60 determines the excitation current value C_Curr as a characteristic physical quantity Prm in step S14. However, the control device may further determine the rotational speed difference between the first friction surface and the second friction surface. Referring again to Figures 6 and 7, in step S14, the control device may further determine whether the rotational speed difference between the first friction surface and the second friction surface is less than or equal to an allowable value N2, which is greater than the target value N1 described above. That is, if the excitation current value C_Curr is greater than or equal to the threshold Th1, and the rotational speed difference between the first friction surface and the second friction surface is less than or equal to the allowable value N2, the control device may determine that the switching control is complete. Also, if the rotational speed difference between the first friction surface and the second friction surface is greater than the allowable value N2, the control device may return to step S11 and redo the synchronization. This allows for resynchronization if, for any reason, the rotational speed difference between the first and second friction surfaces increases while they are in frictional contact. [Explanation of symbols]

[0147] 1, 2: Drive unit 10: Engine 11: Piston 12: Crankshaft 121: First output section 122: Second output section 20: Battery 21: Connection wiring 30: Drive output member 40, 401: Clutch 41: 1st friction surface 42:Second friction surface 43: Actuator 44: Clutch sensor 45: First Pulley 50: Power transmission member 51: Cogbelt 52: Second Pulley 53:Reducer 60: Control device 71: Centrifugal fan 72: Radiator 100: Vehicles MG1: Generator motor MG2: Drive motor PT1: Drive force transmission path SN11: First rotational speed sensor SN12: Second rotational speed sensor TR1: Drive wheel

Claims

1. The engine and A power generation motor that functions as at least a generator when driven by the aforementioned engine, Battery and A drive output member that outputs driving force, A drive motor that is rotated by power supplied at least from the battery and connected to the drive output member in a manner that it can transmit rotational force, A clutch is provided in the drive force transmission path between the drive output member and the engine, and switches the drive force transmission path between a drive force disconnection state and a drive force connection state. The engine, the generator motor, the drive motor, and the control device for controlling the clutch, A drive device equipped with, The aforementioned clutch is It is a friction clutch that is not a meshing clutch, and has a first friction surface and a second friction surface, each provided with a friction material, and the first friction surface and the second friction surface are positioned side by side in the relative movement direction which is the axial or radial direction of the rotation axis of the first friction surface and the second friction surface. When the driving force is disconnected from the state in which the first friction surface and the second friction surface are separated in the relative movement direction, to the state in which the driving force is connected, the driving force of the engine is transmitted to the driving force transmission path, and A characteristic physical quantity, including at least one of a physical quantity other than the rotational speed difference between the first and second friction surfaces, which relates to the relative position between the first and second friction surfaces, and a physical quantity related to the pressure or current pressing between the first and second friction surfaces, has different characteristics in the driving force disconnected state and the driving force connected state. The control device is When the drive unit is operating in a normal state, and the drive unit switches from a series mode in which the power generator motor is driven by the engine's driving force and drives the drive motor using at least that power when the drive force transmission path is disconnected by the clutch, to a parallel mode in which the drive output member is driven by at least one of the driving forces of the engine and the drive motor when the drive force transmission path is connected by the clutch, [a] Control at least one of the engine or the power generation motor so as to suppress the effect of synchronizing rotational speed due to frictional contact between the first friction surface and the second friction surface when the clutch is operated, thereby bringing the rotational speed difference between the first friction surface and the second friction surface close to zero when the driving force transmission path by the clutch is disconnected. [b] Without maintaining the clutch in an intermediate drive force connection state in which a drive force lower than the drive force transmitted in the drive force connection state of the drive force transmission path, the clutch is activated so that the characteristic physical quantity reaches a value indicating the drive force connection state, and then at least one of the engine or the drive motor is controlled to change the drive force that drives the drive output member. Drive unit.

2. In the drive device according to claim 1, A first rotational speed sensor that detects a physical quantity correlated with the rotational speed of the first friction surface, A second rotational speed sensor that detects a physical quantity correlated with the rotational speed of the second friction surface, Equipped with, The control device is Based on the signals from the first rotational speed sensor and the second rotational speed sensor, the generator motor or the engine is controlled so that the rotational speed difference between the first friction surface and the second friction surface is less than or equal to a target value including zero. Drive unit.

3. In the drive device according to claim 1 or 2, The aforementioned clutch is If the friction clutch is a hydraulic friction clutch that operates hydraulically, a clutch sensor detects a physical quantity correlated with the operating hydraulic pressure, or a physical quantity correlated with the position of the operating member of the actuator that generates the operating hydraulic pressure, as the characteristic physical quantity. If the friction clutch is an electromagnetic friction clutch that operates using electromagnetic force, a clutch sensor that detects a physical quantity correlated with the electromagnetic force, or a physical quantity correlated with the position of the operating member of the actuator that generates the electromagnetic force, as the characteristic physical quantity, or In the case where the friction clutch is an electric motor-driven friction clutch, a clutch sensor detects a physical quantity that correlates with the amount of operation of the electric motor, or a physical quantity that correlates with the position of the operating member operated by the electric motor, as the characteristic physical quantity. Includes, The control device is Based on the signal from the clutch sensor, after the detected characteristic physical quantity reaches a value indicating the drive force connection state, the engine or the drive motor is controlled to change the drive force that drives the drive output member. Drive unit.

4. In the drive device according to any one of claims 1 to 3, The aforementioned clutch is The actuator includes an actuator that changes the relative position of the first friction surface and the second friction surface in the relative movement direction, The control device is The actuator is operated with an operation command that does not maintain the aforementioned intermediate connection state of the driving force. Drive unit.

5. In the drive device according to any one of claims 1 to 4, The aforementioned clutch is The actuator includes an electromagnetic actuator that includes an electromagnetic coil for changing the relative position of the first friction surface and the second friction surface in the relative movement direction, The control device is While the drive device is operating under normal conditions, the actuator is activated by controlling at least one of the power generation motor or engine to reduce the rotational speed difference between the first friction surface and the second friction surface to near zero, so that the state in which the first friction surface and the second friction surface are in contact but slipping is suppressed, and then by energizing the electromagnetic coil so that the first friction surface and the second friction surface move from a separated state to a state of contact with minimal slippage. Drive unit.

6. In the drive device according to any one of claims 1 to 5, The aforementioned clutch is The aforementioned friction material is a dry friction material that does not require oil lubrication. This is a single-plate type composed of a pair of rotating bodies in which the relative position of the first friction surface and the second friction surface in the axial direction changes, The control device is While the drive unit is operating normally, the generator motor or the engine is controlled to reduce the rotational speed difference of the dry friction material to near zero so that the state in which the dry friction material is in contact but slipping is suppressed, and then the clutch is activated so that the dry friction material moves from a separated state to a state of contact with minimal slippage. Drive unit.

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