JP2013035404A - Hybrid vehicle and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent seizure of a transmission during reverse running in which an oil pump that allows rotation in only one direction cannot supply lubricating oil to the transmission.
An oil pump supplies lubricating oil to a transmission only in accordance with rotation in one direction of a drive shaft that rotates based on mechanical power from at least one of an engine and an electric motor. The drive shaft that drives the pump rotates in the direction to supply lubricant when established in the forward gear in the transmission, while in the opposite direction that does not supply lubricant when established in the reverse gear. Provided to rotate. While the vehicle is traveling in a state where the reverse gear is established in the transmission, the oil cannot be supplied to the transmission by the oil pump. In such a case, by performing control to limit the vehicle speed of the vehicle, even if the lubricating oil cannot be supplied from the oil pump to the transmission, seizure of the transmission due to oil film shortage does not occur immediately.
[Selection] Figure 3

Description

  The present invention relates to a vehicle (so-called hybrid vehicle) including an internal combustion engine and an electric motor as a drive source and a control method thereof, and in particular, a mechanical oil pump that allows only one-way rotation is operated only during forward travel. The present invention relates to a technique for preventing seizure of a transmission during reverse (reverse driving) in which lubricating oil cannot be supplied to the transmission when provided in the transmission.

  2. Description of the Related Art In recent years, a transmission for a vehicle has an input shaft (hereinafter referred to as a first input shaft) of a first transmission mechanism configured with an odd number of shift stages in order to eliminate the interruption of transmission of mechanical power during a shift. ) And the output shaft of the internal combustion engine (hereinafter referred to as the engine output shaft or the engine output shaft), and the input shaft (hereinafter referred to as the input shaft of the second transmission mechanism) composed of an even number of shift stages. There is known a so-called dual clutch type transmission that includes a second clutch capable of engaging an engine output shaft and a second clutch capable of engaging with the engine output shaft and performing a shift by alternately switching these two clutches. Yes. For example, when shifting from an odd speed to an even speed, this dual clutch transmission is pre-engaged with an even speed gear pair (called pre-shift or pre-shift) and transmits mechanical power to the odd speed. The disengagement of the power transmission at the time of shifting is suppressed by bringing the first clutch to be disengaged and the second clutch that transmits mechanical power to the even-numbered stages into the engaged state.

  Patent Document 1 shown below shows a hybrid type vehicle that includes two transmission mechanisms as described above and further includes an electric motor (motor) that engages with an input shaft of one transmission mechanism. In such a hybrid vehicle, any one of an engine traveling alone with an engine traveling alone, a motor traveling alone with a motor traveling alone, and a hybrid traveling traveling with a combination of an engine and an electric motor, It is appropriately controlled according to the driving situation.

  In addition, a hybrid vehicle is also provided with a mechanical oil pump for supplying lubricating oil (or hydraulic oil) to the transmission (see, for example, Patent Document 2 shown below). As shown in Patent Document 2, in a hybrid vehicle, the mechanical oil pump is operated by using a drive source such as an engine or an electric motor as it is as a power source of the oil pump without using a separate power source. I have to.

JP 2010-164192 A JP 2006-183861 A

  By the way, there is a demand for using a type of oil pump that allows only one-way rotation as a mechanical oil pump that supplies lubricating oil to a transmission from the viewpoint of cost reduction or the like in a hybrid vehicle. However, in a hybrid vehicle having a dual clutch transmission as shown in Patent Document 1, when a drive source such as an engine and an electric motor is used as it is as a power source for an oil pump, the forward movement is unavoidable. The mechanical oil pump can only be arranged so as to rotate forward during traveling but reversely during reverse traveling. Therefore, conventionally, the oil pump is arranged so as to be able to supply lubricating oil to the transmission by operating during forward traveling, which generally has more travel opportunities than reverse traveling. More specifically, the oil pump is provided so as to operate when the first input shaft engaged with the electric motor is rotating forward.

  However, although there are fewer travel opportunities compared to forward travel, the oil pump will not operate during reverse travel, and if the transmission cannot be lubricated, especially when high speed / long time reverse travel is performed, the oil film runs out. This is very inconvenient because it may cause seizure of the transmission.

  The present invention has been made in view of the above points. In a hybrid vehicle including a transmission including a mechanism in which a drive source such as an engine and an electric motor is shared as a power source of a mechanical oil pump that supplies lubricating oil. An object of the present invention is to provide a hybrid vehicle and a control method for the hybrid vehicle in which the vehicle speed is limited to prevent the seizure of the transmission during reverse traveling when the mechanical oil pump is not operated and no lubricating oil is supplied to the transmission. is there.

  A hybrid vehicle according to a first aspect of the present invention includes a first input shaft (IMS) and a second input shaft (OMS) arranged coaxially, and the first input shaft (IMS) is connected to the electric motor (3). A first connecting / disconnecting means (C1) for transmitting a driving force of the engine (2) to the first input shaft (IMS); and a driving force of the engine (2) transmitted to the second input shaft. The second connecting / disconnecting means (C2) for transmitting to the (OMS), the first input shaft (IMS), the output shaft (CS) arranged in parallel with the second input shaft (OMS), and the first input. A reversing mechanism for reversing the rotational direction between the shaft (IMS) and the second input shaft (OMS) and transmitting a driving force; and a first input shaft (IMS) and a second input shaft (OMS) Input gear (43, 45, 47) provided on one side and provided on the output shaft (CS) Output gears (51, 52, 53) that are always linked to the input gears (43, 45, 47), and when a predetermined forward shift speed is established, the driving force of the engine (2) is One of the first connecting / disconnecting means (C1) and the second connecting / disconnecting means (C2), and the input gear (43, 43) provided on one of the first input shaft (IMS) and the second input shaft (OMS). 45, 47) and the output gears (51, 52, 53) provided on the output shaft (CS) are transmitted to the drive wheels (7R, 7L), and when the reverse gear is established, the engine The driving force of (2) includes the other of the first connecting / disconnecting means (C1) and the second connecting / disconnecting means (C2), the reversing mechanism, the first input shaft (IMS), and the second input shaft. (OMS) provided with one of the input gears (43, 45, 47) and the output A transmission (4) transmitted to the drive wheels (7R, 7L) via the output gears (51, 52, 53) provided in (CS), and at least the engine (2), A mechanical oil pump (OP) capable of supplying lubricating oil to the transmission (4) only in accordance with rotation in one direction of a drive shaft (OS) that rotates based on mechanical power from one of the electric motors (3). ), And the drive shaft (OS) rotates in a direction to supply lubricating oil when established in the forward shift stage in the transmission (4), while reverse in the transmission (4). When the gear is established at the gear position, the oil is rotated in the opposite direction without supplying the lubricant, and the transmission (4) is in the state established at the reverse gear position at the transmission (4) by the oil pump (OP). Supply of lubricant to Control means (10) for performing control to limit the vehicle speed of the vehicle when the vehicle cannot be operated.

  The hybrid vehicle according to the present invention is a vehicle having an engine (2) and an electric motor (3) as a drive source, and has a first clutch and a second connection / disconnection means (C1, C2). In the case where the transmission (4) is provided, when the oil cannot be supplied from the oil pump (OP) to the transmission (4), the vehicle speed of the vehicle is controlled. The oil pump (OP) is configured to transmit the transmission (4) only in accordance with rotation in one direction of a drive shaft (OS) that rotates based on mechanical power from at least one of the engine (2) and the electric motor (3). ) Is a mechanical oil pump capable of supplying lubricating oil. The drive shaft (OS) for driving the oil pump (OP) rotates in a direction to supply lubricating oil when established in the forward shift stage in the transmission (4), while the transmission (4 ) Is provided so as to rotate in the opposite direction without supplying lubricating oil. While the vehicle is traveling with the transmission (4) established at the reverse gear, the oil pump (OP) cannot supply the lubricating oil to the transmission (4). In such a case, by controlling the vehicle speed of the vehicle, even if the oil pump (OP) cannot supply lubricating oil to the transmission (4), the transmission (4) is burned out due to oil film breakage. Will not occur immediately.

  A hybrid vehicle according to claim 2 of the present invention has an engine (2) and an electric motor (3) as a drive source, and is connected to the electric motor (3) while being connected to the engine output shaft. An input shaft (IMS) that can be switched between engagement and disengagement, and mechanical power from the engine output shaft and the electric motor (3) is received by the input shaft (IMS), and a plurality of speed stages A transmission (4) capable of engaging any one of them to engage the input shaft (IMS) and the drive wheels (7R, 7L), wherein the transmission (4) The speed change only according to the rotation of the drive shaft (OS) rotated in one direction based on the mechanical power from the motor (3) and the one that can be switched to forward traveling or reverse traveling depending on the rotation direction of the electric motor (3). Machine that can supply lubricating oil to the machine (4) The drive shaft (OS) is rotated in a direction to supply lubricating oil when the transmission (4) is switched to forward travel, while the transmission (OP) When 4) is switched to reverse running, the transmission (4) is switched to reverse running according to the rotation direction of the electric motor (3), and the transmission (4) is rotated in the opposite direction without supplying lubricant. And a control means (10) for performing control to limit the vehicle speed of the vehicle when the lubricating oil cannot be supplied to the transmission (4) by the oil pump (OP). As a result, even in a hybrid vehicle that is not a dual clutch transmission, the oil film is cut by restricting the vehicle speed during reverse travel in which the oil pump (OP) cannot supply the lubricating oil to the transmission (4). The transmission (4) due to the seizure does not occur immediately.

  Note that the reference numerals in the parentheses described above exemplify the corresponding constituent elements in the embodiments described later for reference.

  According to the present invention, in a hybrid vehicle equipped with a dual clutch transmission or a hybrid vehicle equipped with a transmission that is not a dual clutch transmission, a mechanical oil pump capable of supplying lubricating oil only in accordance with rotation in one direction is provided. Because it is used, there is an effect that the seizure of the transmission due to oil film shortage does not occur immediately by performing control to limit the vehicle speed of the vehicle during reverse traveling where the lubricating oil cannot be supplied to the transmission. .

The schematic connection block diagram of the vehicle in one Embodiment of this invention. The skeleton figure of the transmission shown in FIG. The flowchart which shows the outline of the vehicle speed limiting process at the time of reverse driving | running | working performed by the electronic control unit shown in FIG. The timing chart for demonstrating the vehicle speed restriction | limiting at the time of reverse driving | running | working.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  First, the configuration of the vehicle in the present embodiment will be described. FIG. 1 is a schematic connection configuration diagram of a vehicle according to an embodiment of the present invention. The vehicle 1 of this embodiment is what is called a hybrid vehicle, and as shown in FIG. 1, the engine 2 and the motor 3 as a drive source, the motor control means 20 for controlling the motor 3, the battery 30, and the speed change Machine 4, differential mechanism 5, left and right drive shafts 6 </ b> R and 6 </ b> L, left and right drive wheels 7 </ b> R and 7 </ b> L, and electric servo brake 8. The rotational driving force of the engine 2 and the motor generator 3 is transmitted to the left and right drive wheels 7R, 7L via the transmission 4, the differential mechanism 5, and the drive shafts 6R, 6L.

  The vehicle 1 includes an electronic control unit (ECU) 10 for controlling the engine 2, the motor 3, the transmission 4, the differential mechanism 5, the electric servo brake 8, the motor control means 20, and the battery 30, respectively. Is provided. The electronic control unit 10 is not only configured as a single unit, but also controls, for example, an engine ECU for controlling the engine 2, a motor generator ECU for controlling the motor generator 3 and the motor generator control means 20, and the battery 30. For example, a battery ECU for controlling the transmission 4 and an AT ECU for controlling the transmission 4. The electronic control unit 10 shown in this embodiment controls the engine 2 and also controls the motor 3, the battery 30, the transmission 4, and the electric servo brake 8.

  The electronic control unit 10 performs control so that the motor alone travels (EV travel) using only the motor 3 as a power source according to various operating conditions, or performs the engine alone travel using only the engine 2 as a power source. Control is performed so as to perform cooperative traveling (HEV traveling) in which both the engine 2 and the motor 3 are used as power sources. Further, the electronic control unit 10 performs various types of control (see FIG. 3) necessary for limiting the vehicle speed during reverse traveling, which will be described later, and other types of control necessary for various driving operations according to various known control parameters. In this embodiment, as control parameters, for example, the shift position from the shift sensor A1 that detects the engaged gear stage (shift stage), the motor rotation speed from the rotation speed sensor A2 that detects the rotation speed of the motor 3, Motor torque from a torque sensor A3 (for example, a resolver) that detects torque of the motor 3, vehicle speed from a vehicle speed sensor A4 that detects the speed of the vehicle, and engine rotation from a rotation speed sensor A5 that detects the rotation speed of the engine 2 Depending on the number, the engine torque from the torque sensor A6 for detecting the torque of the engine 2, and other signals from the sensor A7 such as the accelerator pedal opening and the brake pedal opening according to the operation of the driver and the road gradient. The tilt angle of the vehicle is entered. Of course, signals other than those described here may be input.

  The engine 2 is an internal combustion engine that generates driving force for running the vehicle 1 by mixing fuel with air and burning it. The motor 3 functions as a motor that generates a driving force for running the vehicle 1 using the electric energy of the battery 30 when the engine 2 and the motor 3 are collaboratively run or when the EV 3 is driven only by the motor 3. In addition, when the vehicle 1 decelerates, it also functions as a generator that generates electric power by regeneration of the motor 3. That is, the motor 3 is a brushless DC motor such as a permanent magnet type three-phase AC motor using a permanent magnet as a field, and is connected to the motor control means 20. The motor control means 20 is, for example, an inverter (power converter), which converts a DC voltage received from the battery 30 into a three-phase AC voltage according to switching control by the electronic control unit 10 and supplies the converted three-phase AC voltage to the motor 3. Output. As a result, the motor 3 is driven to generate a designated torque. Further, the motor control means 20 receives the output of the engine 2 and converts the three-phase AC voltage generated by the motor 3 into a DC voltage according to switching control by the electronic control unit 10 and outputs the converted DC voltage to the battery 30. . During regeneration of the motor 3, the battery 30 is charged with electric power (regenerative energy) generated by the motor 3.

  The electric servo brake 8 includes an electric motor different from the motor 3 and a hydraulic servo (not shown), and the drive wheels 7R and 7L are operated by operating the hydraulic servo in accordance with the control of the electric motor. It is a brake that mechanically brakes. The electronic control unit 10 controls the electric motor by sending a predetermined signal via a signal line (so-called brake-by-wire). Here, for convenience of illustration, only one electric servo brake 8 is shown on the drive wheel 7R side, but the electric servo brake 8 may also be provided on the drive wheel 7L side.

  Next, the configuration of the transmission 4 according to the present embodiment will be described. FIG. 2 is a skeleton diagram of the transmission 4 shown in FIG. The transmission 4 shown here is a parallel shaft transmission of 7 forward speeds and 1 reverse speed, and is a dry dual clutch transmission (DCT: dual clutch transmission).

  The transmission 4 includes a crankshaft (not shown) forming an engine output shaft of the engine 2 and an inner main shaft IMS (first input shaft) connected to the motor 3 and an outer cylinder of the inner main shaft IMS. The outer main shaft OMS (second input shaft), the secondary shaft SS (second input shaft) parallel to the inner main shaft IMS, the idle shaft IDS, the reverse shaft RVS, and the counter that forms an output shaft parallel to these shafts A shaft CS is provided.

  Out of these shafts, the outer main shaft OMS is always engaged with the reverse shaft RVS and the secondary shaft SS via the idle shaft IDS, and the counter shaft CS is further always engaged with the differential mechanism 5 (not shown in FIG. 2). Be placed.

  The transmission 4 includes a first clutch C1 (first connecting / disconnecting device) for odd-numbered stages and a second clutch C2 (second connecting / disconnecting apparatus) for even-numbered stages. The first and second clutches C1 and C2 are dry clutches. The first clutch C1 is coupled to the inner main shaft IMS (first input shaft). The second clutch C2 is coupled to the outer main shaft OMS (a part of the second input shaft) and is connected to the reverse shaft RVS and the secondary shaft SS (first shaft) from the gear 48 fixed on the outer main shaft OMS via the idle shaft IDS. 2 part of the input shaft).

  A planetary gear mechanism 70 is fixedly disposed at a predetermined position from the motor 3 of the inner main shaft IMS (first input shaft). The sun gear 71 of the planetary gear mechanism 70 is the rotor of the motor 3 and the carrier 73 is the third-speed drive gear 43. The ring gear 75 is connected to the inner main shaft IMS (first input shaft). On the outer periphery of the inner main shaft IMS (first input shaft), in order from the left side in FIG. 2, a carrier 73 of a planetary gear mechanism 70 serving as a first speed drive gear, a third speed drive gear 43, a seventh speed drive gear 47, A fifth speed drive gear 45 is arranged. The third speed drive gear 43, the seventh speed drive gear 47, and the fifth speed drive gear 45 are rotatable relative to the inner main shaft IMS, and the gear 43 is connected to the carrier 73 of the planetary gear mechanism 70 as described above. Has been. Further, on the inner main shaft IMS, a 3-7 speed synchromesh mechanism (selector mechanism) 81 is provided between the 3rd speed drive gear 43 and the 7th speed drive gear 47 so as to be slidable in the axial direction. Corresponding to the high-speed drive gear 45, a 5-speed synchromesh mechanism (selector mechanism) 82 is provided to be slidable in the axial direction. By sliding a synchromesh mechanism (selector mechanism) corresponding to a desired gear stage and inserting the gear stage, the gear stage is connected to the inner main shaft IMS (first input shaft). These gears and synchromesh mechanisms provided in association with the main shaft IMS (first input shaft) constitute a first transmission mechanism for realizing an odd number of shift stages. Each drive gear of the first speed change mechanism meshes with a corresponding driven gear provided on the countershaft CS to rotationally drive the countershaft CS.

  On the outer periphery of the secondary shaft SS (second input shaft), a second speed drive gear 42, a sixth speed drive gear 46, and a fourth speed drive gear 44 are relatively rotatably arranged in order from the left side in FIG. . Further, on the secondary shaft SS, a 2-6 speed synchromesh mechanism 83 is provided between the 2nd speed drive gear 42 and the 6th speed drive gear 46 so as to be slidable in the axial direction. Correspondingly, a 4-speed synchromesh mechanism (selector mechanism) 84 is provided to be slidable in the axial direction. Also in this case, the gear stage is connected to the secondary shaft SS (second input shaft) by sliding the synchromesh mechanism (selector mechanism) corresponding to the desired gear stage and inserting the gear stage. These gears and synchromesh mechanisms provided in association with the secondary shaft SS (second input shaft) constitute a second transmission mechanism for realizing an even number of shift stages. Each drive gear of the second speed change mechanism also meshes with a corresponding driven gear provided on the countershaft CS to rotate the countershaft CS. The gear 49 fixed to the secondary shaft SS is coupled to the idle shaft IDS, and is coupled from the idle shaft IDS to the second clutch C2 via the outer main shaft OMS.

  In the first speed change mechanism, selecting an arbitrary gear position means that the gear corresponding to the gear position is synchronized and the gear is connected to the inner main shaft IMS (first input shaft). Means. Further, in the first speed change mechanism, to realize a speed stage (or drive gear stage) for running the engine means that the speed stage (or drive gear stage) is selected as described above (with synchronization). This means that the corresponding first clutch C1 is engaged to connect the inner main shaft IMS (first input shaft) to the engine output shaft.

  Similarly, in the second speed change mechanism, when an arbitrary certain speed is selected, the gear corresponding to the speed is synchronized and the gear is connected to the secondary shaft SS (second input shaft). Means. Further, in this second speed change mechanism, to realize a speed stage (or drive gear stage) for running the engine means that the speed stage (or drive gear stage) is selected as described above (with synchronization). This means that the corresponding second clutch C2 is engaged to connect the secondary shaft SS (second input shaft) to the engine output shaft.

  A reverse drive gear 46 is disposed on the outer periphery of the reverse shaft RVS so as to be relatively rotatable. On the reverse shaft RVS, a reverse synchromesh mechanism 85 corresponding to the reverse drive gear 46 is slidable in the axial direction, and a gear 50 that engages with the idle shaft IDS is fixed. When traveling in reverse, the synchromesh mechanism 85 is synchronized and the second clutch C2 is engaged to transmit the rotation of the second clutch C2 to the reverse shaft RVS via the outer main shaft OMS and the idle shaft IDS. Then, the reverse drive gear 46 is rotated. The reverse drive gear 46 meshes with the gear 56 on the inner main shaft IMS, and when the reverse drive gear 46 rotates, the inner main shaft IMS rotates (reversely rotates) in the opposite direction to that during forward movement. The rotation in the reverse direction of the inner main shaft IMS is transmitted to the countershaft CS via the gear 43 connected to the planetary gear mechanism 70. The gear and synchromesh mechanism provided in association with the reverse shaft RVS constitutes a reversing mechanism for realizing a reverse gear.

  Since the reverse drive gear 46 meshes with the gear OG on the oil pump drive shaft OS, the rotation of the reverse drive gear 46 is transmitted to the oil pump drive shaft OS via the gear OG. As the oil pump drive shaft OS rotates, the oil pump OP that supplies lubricating oil (operating oil) to each part of the first transmission mechanism and the second transmission mechanism is driven. That is, since the reverse drive gear 46 rotates as the engine 2 and / or the electric motor 3 is driven, the drive source such as the engine 2 and the electric motor 3 is shared as a power source of the oil pump OP in this embodiment. It will be. However, since the mechanical oil pump OP is a type of oil pump that only allows rotation in one direction, the oil pump drive shaft OS rotates in the forward direction (in this case, for example, the direction of the arrow with the symbol X in the drawing is convenient. When the oil pump drive shaft OS rotates in the reverse direction, the oil pump drive shaft OS does not operate and operates to supply the lubricating oil to each part of the transmission 4. Do not supply lubricant.

  On the countershaft CS, in order from the left side in FIG. 2, the 2-3 speed driven gear 51, the 6-7 speed driven gear 52, the 4-5 speed driven gear 53, the parking gear 54, and the final drive gear are arranged. 55 is fixedly arranged. The final drive gear 55 is adapted to mesh with a differential ring gear (not shown) of the differential mechanism 5, whereby the rotation of the output shaft of the counter shaft CS causes the input shaft of the differential mechanism 5 (that is, the vehicle propulsion shaft, the foot). Also called an axis).

  A one-way clutch 41 is provided so as to engage with the ring gear 75 and the planetary gears 72 and 74 of the planetary gear mechanism 70.

  When the synchromesh of the 2-6 speed synchromesh mechanism 83 is slid leftward, the 2nd speed drive gear 42 is coupled to the secondary shaft SS, and when slid rightward, the 6th speed drive gear 46 is coupled to the secondary shaft SS. . When the synchromesh of the 4-speed synchromesh mechanism 84 is slid rightward, the 4-speed drive gear 44 is coupled to the secondary shaft SS. By engaging the second clutch C2 with the even-numbered drive gear stage selected in this way, the transmission 4 is set to an even-numbered gear stage (second speed, fourth speed, or sixth speed).

  When the synchromesh of the 3-7 speed synchromesh mechanism 81 is slid to the left, the 3rd speed drive gear 43 is coupled to the inner main shaft IMS to select the 3rd speed, and when it is slid to the right, the 7th speed is driven. The gear 47 is coupled to the inner main shaft IMS to select the seventh speed. When the synchromesh of the 5-speed synchromesh mechanism 82 is slid to the right, the 5-speed drive gear 45 is coupled to the inner main shaft IMS, and the 5-speed gear stage is selected. In a state where none of the gears 43, 47, 45 is selected by the synchromesh mechanisms 81, 82, the rotation of the carrier 73 of the planetary mechanism 70 is transmitted to the countershaft CS via the gear 43 connected thereto, and the first gear The gear position is selected. By engaging the first clutch C1 with the odd drive gear selected, the transmission 4 is set to an odd gear (1st, 3rd, 5th, or 7th).

  Determination of the shift speed to be realized by the transmission 4 and control for realizing the shift speed (selection of the shift speed in the first transmission mechanism and the second transmission mechanism, that is, synchro switching control, first clutch and second clutch) The control of the engagement and disengagement (disengagement), etc.) is executed by the electronic control unit 10 according to the driving situation as is well known.

  As can be understood from FIG. 2, in the dual clutch transmission 4 shown in FIG. 2, at least the rotation direction of the oil pump drive shaft OS and the rotation direction of the inner main shaft IMS are always the same. Therefore, the rotation direction (forward rotation or reverse rotation) of the oil pump drive shaft OS that affects the operation of the oil pump OP rotates forward during forward travel where the inner main shaft IMS rotates forward, and the inner main shaft IMS reverses. Reverse rotation occurs during reverse rotation. As described above, when the oil pump drive shaft OS rotates in the reverse direction, the oil pump OP does not operate and the lubricating oil is not supplied to each part of the transmission 4, so that the oil pump drive shaft OS rotates in the reverse direction. When the reverse running is performed at a high speed / for a long time, there is a great possibility that the transmission 4 is seized due to the absence of the lubricant.

  Therefore, in the hybrid vehicle shown in the present embodiment, in order to prevent the seizure of the transmission 4 during the reverse traveling, the transmission is immediately performed even if the lubricating oil is not supplied for a certain period of time when the reverse traveling is being performed. An electronic control unit (ECU) 10 controls the vehicle speed to automatically limit the vehicle speed during reverse running so that the vehicle speed is less than the vehicle speed (for example, around 30 km, hereinafter referred to as the limited vehicle speed) that does not cause burn-in to 4. To be executed. The “restricted vehicle speed” may be changed with the passage of time since the reverse running of the vehicle is started. Specifically, the restricted vehicle speed may be changed to a slower speed as a long time passes.

  Next, an example of control for limiting the vehicle speed during reverse running, which is executed by the electronic control unit 10, will be described with reference to FIGS. FIG. 3 is a flowchart showing an embodiment of the vehicle speed limiting process during reverse running. The vehicle speed limiting process shown in FIG. 3 is repeatedly executed while the vehicle is in operation, for example, when the ignition key is turned on by the driver and until the ignition key is turned off. You can do it. FIG. 4 is a timing chart for explaining the vehicle speed limitation during reverse running. From the top, the driver (driver) performs a deceleration operation (for example, an accelerator off operation or a brake on operation), a gear stage (shift position), a vehicle Indicates the change in the slope of the road while traveling, the vehicle speed, the engine slow torque request, and the motor torque request.

  Step S1 determines whether or not the vehicle is traveling in reverse. As for the reverse travel in the hybrid vehicle, as in the forward travel, three different travels in which the drive source is the engine 2 only (engine single travel), the motor 3 only (motor single travel), the engine 2 and the motor 3 (hybrid travel). There can be embodiments. The determination as to whether or not the vehicle is traveling in reverse is performed when a predetermined determination condition (of course, not limited to this) is satisfied, for example, the shift position is reverse (reverse) and the vehicle speed is not “0”. In addition, it is determined that the vehicle is traveling in reverse. If it is determined that the vehicle is not traveling in reverse according to the above conditions (NO in step S1), the process is terminated. That is, when the vehicle is not traveling in reverse but traveling in the forward gear, the oil pump OP is rotating forward (in the direction of arrow X in FIG. 2), and there is a risk that the supply of lubricating oil to the transmission 4 will be delayed. Therefore, it is not necessary to perform control for limiting the vehicle speed as shown below.

  If it is determined that the vehicle is traveling in reverse (YES in step S1), it is determined whether or not the speed (vehicle speed) of the vehicle that is traveling in reverse is greater than or equal to a predetermined vehicle speed limit (step). S2). If it is determined that the speed of the vehicle traveling in the reverse direction is not equal to or higher than the vehicle speed limit (NO in step S2), even if the oil pump OP rotates in the reverse direction (opposite the direction of the arrow X in FIG. 2), the transmission 4 Since the reverse traveling is performed at a relatively slow vehicle speed at which there is little possibility that the lubricating oil will stagnate, the processing may be terminated without particularly limiting the vehicle speed.

  On the other hand, if it is determined that the speed of the vehicle traveling in reverse is equal to or higher than the vehicle speed limit (YES in step S2), the engine brake is controlled by executing control to reduce the torque of the engine 2 based on the engine slow torque request. (Step S3). The control for reducing the engine torque that is executed to apply the engine brake differs depending on the running mode of the vehicle at that time. For example, when the engine is traveling alone or during hybrid traveling, the engine 2 itself is controlled so that the output torque is lower than the target engine torque determined from the selected drive gear or accelerator pedal opening, or the fuel supply is cut. What is necessary is just to perform control which stops the engine 2 inside. When the motor is traveling alone, control for fastening the first clutch C1 connected to the inner main shaft IMS may be performed so that the engine 2 that is not driven is rotated by the rotation of the motor 3. Step S4 performs control to turn off the motor 3 that is reversely driven based on the motor torque request in the case of the reverse traveling by the hybrid traveling or the motor independent traveling (at this time, the first clutch C1 is in the released state). It is in).

  In step S <b> 5, it is determined whether or not the vehicle speed is less than “restricted vehicle speed + reset offset value” by adjusting the vehicle speed using the engine 2. Here, the reset offset value is a predetermined value (for example, -5 km). If it is determined that the vehicle speed is lower than the “restricted vehicle speed + reset offset value (for example, 30-5 = 25 km)” (YES in step S5), the vehicle speed may be sufficiently reduced by adjusting the vehicle speed using the engine 2. As a result, the control for reducing the engine torque executed in step S3 is terminated (step S10), and the process is terminated.

  As shown in FIG. 4, when the shift speed is changed from neutral to reverse speed and reverse travel is started (this time is set to time t0 for convenience), the vehicle increases in speed in accordance with the change in road gradient. While driving. At this time, the oil pump OP does not operate because the rotation direction of the oil pump drive shaft OS is reversed, and the transmission 4 is not supplied with lubricating oil. In particular, when the vehicle is traveling reversely on an uphill slope, the vehicle speed increases gradually according to the slope regardless of the driver's intention (that is, even if the driver does not step on the accelerator). To go.

  As described above, it is inconvenient if the speed of the vehicle increases more than necessary during reverse running and the oil pump OP does not supply the lubricating oil to the transmission 4, so it is inconvenient. (Time t1), first, the engine brake is applied by performing a control to reduce the torque of the engine 2 or stop the engine 2 in order to realize a reduction in the vehicle speed by adjusting the vehicle speed using the engine 2. At this time, if the motor 3 is being driven, the motor 3 is also turned off at the same time, so the output torque of the motor 3 becomes “0”. If the vehicle speed is gradually reduced by adjusting the vehicle speed using the torque of the engine 2 and falls below the “limit speed + reset offset value” (see after time t5), the engine slow torque request and the motor torque request are made. Return to the target engine torque and target motor torque specified before the vehicle speed limit, respectively, and reverse travel at any speed below the "limit speed + reset offset value" (speed according to the target engine torque and / or target motor torque) Control to continue. If the vehicle speed can be reduced, the possibility of seizure of the transmission 4 can be greatly reduced.

  By adjusting the vehicle speed using the torque of the engine 2 as described above, the vehicle speed may be lower than the “limit speed + reset offset value”. For example, when the vehicle is traveling reversely on an uphill road of 5% or more. If the vehicle continues to run at the speed around the limit vehicle speed without dropping too much (see time t1 to time t2), or if the gradient changes further suddenly, the vehicle speed may rise again above the limit vehicle speed (see time t3). ). If so, it is not convenient because the state in which the lubricating oil is not supplied to the transmission 4 by the oil pump OP will continue for a longer time.

  Therefore, in the process shown in FIG. 3, when it is determined that the vehicle speed does not fall below the “restricted vehicle speed + reset offset value”, that is, when the vehicle speed cannot be reduced sufficiently by the vehicle speed adjustment using the engine 2. (NO in step S5), control is performed to regenerate the motor 3 according to the motor torque request so as to realize a reduction in vehicle speed by adjusting the vehicle speed using not only the engine 2 (specifically, engine brake) but also the motor 3. (Step S6). In step S7, it is determined whether or not the vehicle speed is less than the “restricted vehicle speed + reset offset value” with the execution of the regeneration control of the motor 3. When it is determined that the vehicle speed has fallen below the “restricted vehicle speed + reset offset value” by regenerative control of the motor 3 (YES in step S7), the vehicle speed is sufficiently reduced by adjusting the vehicle speed using the engine 2 and the motor 3. As a result, the processing is terminated. On the other hand, if it is determined that the vehicle speed does not fall below the “restricted vehicle speed + reset offset value” (NO in step S7), the regenerative control of the motor 3 is continued to further increase the motor torque in step S6. Return to processing.

  As shown in FIG. 4, when the vehicle speed is not greatly reduced by adjusting the vehicle speed using the engine 2 (“restricted vehicle speed + reset offset value” is not below), the regeneration control of the motor 3 is performed. (Time t3). Specifically, the first clutch C1 in the released state is engaged. When the regenerative control of the motor 3 is performed, the torque in the direction opposite to the rotation direction of the inner main shaft IMS at the time of reverse traveling increases, so the speed starts to decrease (time t4). Since the vehicle speed is gradually reduced by adjusting the vehicle speed using the motor torque generated in accordance with the regeneration control of the motor 3, if the vehicle speed can be lowered to a speed lower than the “limit speed + reset offset value” (time) The possibility of seizure of the transmission 4 can be greatly reduced.

  Here, as described above, the battery 30 is charged by the electric power (regenerative energy) generated by the motor 3 in accordance with the regeneration control of the motor 3. However, if the motor 3 is regeneratively controlled when the battery 30 is already fully charged and there is no room for further charging, the battery 30 may be overcharged and broken. Therefore, it is determined whether or not the battery 30 is fully charged before returning to the process of step S6 (step S8), and only when the battery 30 is not fully charged (NO in step S8), the above step S6. Returning to the process, the motor regeneration control is continued. When the battery 30 is in a fully charged state (YES in step S8), the motor 3 cannot be regeneratively controlled from the viewpoint of protection of the battery 30, and eventually the vehicle speed adjustment using the motor 3 is performed. However, the vehicle speed cannot be reduced. However, from the viewpoint of protection of the transmission 4, since it is better to reduce the vehicle speed as much as possible in reverse running where the lubricating oil is not supplied from the oil pump OP, the electric servo brake 8 is automatically set in step S9. The vehicle is controlled to forcibly reduce the vehicle speed.

  As described above, in the hybrid vehicle according to the present invention, the dual clutch type transmission 4 having the engine 2 and the electric motor 3 as the drive source and including the first connecting / disconnecting means C1 and the second connecting / disconnecting means C2. In this case, control is performed to limit the vehicle speed of the vehicle during reverse traveling where the lubricating oil cannot be supplied from the mechanical oil pump OP to the transmission 4. The oil pump OP can supply lubricating oil to the transmission 4 only in accordance with rotation in one direction of the drive shaft OS that rotates based on mechanical power from at least one of the engine 2 and the electric motor 3. When the drive shaft OS rotates in the direction to supply lubricant when the transmission 4 is established at the forward shift stage, the drive shaft OS is established at the reverse shift stage in the transmission 4. It is provided to rotate in the opposite direction without supplying lubricating oil. For this reason, while the vehicle is traveling in the state where the transmission 4 is established at the reverse gear position, the oil pump OP cannot supply the lubricating oil to the transmission 4. Therefore, when the vehicle is traveling in reverse, by limiting the vehicle speed of the vehicle, even if the lubricating oil cannot be supplied to the transmission 4 from the oil pump OP, the transmission 4 is seized due to running out of the oil film. It can be prevented from occurring immediately. As control for limiting the vehicle speed, for example, control for reducing engine torque (see step S3 in FIG. 3), motor regeneration control (see step S6 in FIG. 3), and control of electric servo brake (see step S9 in FIG. 3). and so on.

  As mentioned above, although an example of embodiment was demonstrated based on drawing, this invention is not limited to this, It cannot be overemphasized that various embodiment is possible. For example, in the above-described embodiment, the example in which the hybrid vehicle according to the present invention is applied to a vehicle including a dual clutch transmission including two clutches is not limited thereto. In the case of a hybrid vehicle in which a mechanical oil pump that allows rotation in only one direction operates during forward travel and does not operate during reverse travel, the mechanism of the transmission is a dual clutch as described above. It may not be a mechanism of a formula.

1 Hybrid vehicle 2 Engine 3 Motor (electric motor)
4 Transmission 5 Differential mechanism 6R, 6L Drive shaft 7R, 7L Drive wheel 8 Electric servo brake 10 Electronic control unit 20 Motor control means 30 Battery 70 Planetary gear mechanism 71 Sun gear 72, 74 Planetary gear 73 Carrier 75 Ring gear C1 First clutch C2 Second Clutch IMS Inner main shaft OMS Outer main shaft SS Secondary shaft CS Counter shaft RVS Reverse shaft IDS Idle shaft

Claims (8)

A first input shaft and a second input shaft arranged coaxially, wherein the first input shaft is connected to an electric motor;
First connection / disconnection means for transmitting the driving force of the engine to the first input shaft;
Second connection / disconnection means for transmitting the driving force of the engine to the second input shaft;
An output shaft disposed in parallel with the first input shaft and the second input shaft;
A reversing mechanism for reversing the rotational direction between the first input shaft and the second input shaft to transmit a driving force;
An input gear provided on one of the first input shaft and the second input shaft;
An output gear provided on the output shaft and constantly interlocking with the input gear;
When a predetermined forward shift stage is established, the driving force of the engine is provided to one of the first connecting / disconnecting means and the second connecting / disconnecting means and one of the first input shaft and the second input shaft. When the reverse gear is established, the driving force of the engine is transmitted to the first connecting / disconnecting means and the second connecting gear via the input gear and the output gear provided on the output shaft. Drive wheels via the other connecting / disconnecting means, the reversing mechanism, the input gear provided on one of the first input shaft and the second input shaft, and the output gear provided on the output shaft. A transmission characterized by being transmitted to
A mechanical oil pump capable of supplying lubricating oil to the transmission only in accordance with rotation in one direction of a drive shaft that rotates based on mechanical power from at least one of an engine and an electric motor. When the transmission is established at the forward shift stage, it rotates in the direction to supply lubricant, while when it is established at the reverse shift stage in the transmission, it rotates in the opposite direction without supplying lubricant. things and,
A hybrid vehicle comprising: a control unit that performs control to limit a vehicle speed of the vehicle when the transmission is in a state established at a reverse gear and cannot be supplied to the transmission by the oil pump. It has an engine and an electric motor as a drive source,
An input shaft that is connected to the electric motor and can be switched between engaged and disengaged with the engine output shaft, and mechanical power from the engine output shaft and the electric motor is transmitted by the input shaft. A transmission capable of engaging any one of a plurality of shift speeds to engage the input shaft and the drive wheel, and the transmission travels forward according to the rotation direction of the electric motor. Or one that can be switched to reverse running,
A mechanical oil pump capable of supplying lubricating oil to the transmission only in accordance with rotation in one direction of a drive shaft that rotates based on mechanical power from the electric motor, the drive shaft being driven forward by the transmission When it is switched to traveling when it is switched to the direction of supplying lubricating oil, when the transmission is switched to reverse traveling, it is rotated in the opposite direction not supplying lubricant oil,
Control means for controlling the vehicle speed of the vehicle when the transmission is switched to reverse travel according to the rotation direction of the electric motor and the oil pump cannot supply the lubricating oil to the transmission. A hybrid vehicle equipped with.   2. The control device according to claim 1, wherein the control means reduces the vehicle speed by a differential rotation between the engine and the input shaft, which is generated by performing control for stopping the engine or control for engaging the stopped engine with the input shaft. Or the hybrid vehicle of 2.   3. The hybrid vehicle according to claim 1, wherein the control unit reduces the vehicle speed by performing a control to regenerate the electric motor by limiting mechanical power from the electric motor. 4.   5. The hybrid vehicle according to claim 3, wherein the control unit further reduces the vehicle speed by performing a control to apply a brake that mechanically stops the drive wheels. 6. A method for controlling a hybrid vehicle having an engine and an electric motor as a drive source,
The hybrid vehicle
A first input shaft and a second input shaft arranged coaxially, wherein the first input shaft is connected to the motor;
First connection / disconnection means for transmitting the driving force of the engine to the first input shaft;
Second connection / disconnection means for transmitting the driving force of the engine to the second input shaft;
An output shaft disposed in parallel with the first input shaft and the second input shaft;
A reversing mechanism for reversing the rotational direction between the first input shaft and the second input shaft to transmit a driving force;
An input gear provided on one of the first input shaft and the second input shaft;
An output gear provided on the output shaft and constantly interlocking with the input gear;
When a predetermined forward shift stage is established, the driving force of the engine is provided to one of the first connecting / disconnecting means and the second connecting / disconnecting means and one of the first input shaft and the second input shaft. When the reverse gear is established, the driving force of the engine is transmitted to the first connecting / disconnecting means and the second connecting gear via the input gear and the output gear provided on the output shaft. Drive wheels via the other connecting / disconnecting means, the reversing mechanism, the input gear provided on one of the first input shaft and the second input shaft, and the output gear provided on the output shaft. A transmission characterized by being transmitted to
A mechanical oil pump capable of supplying lubricating oil to the transmission only in accordance with rotation in one direction of a drive shaft that rotates based on mechanical power from at least one of an engine and an electric motor. When the transmission is established at the forward shift stage, it rotates in the direction to supply lubricant, while when it is established at the reverse shift stage in the transmission, it rotates in the opposite direction without supplying lubricant. things and,
Control means for controlling the vehicle speed of the vehicle when the transmission is in a state established at a reverse gear and cannot be supplied to the transmission by the oil pump.
The control means includes
Reducing vehicle speed by differential rotation between the engine and the input shaft generated by performing control for stopping the engine or control for engaging the stopped engine with the input shaft;
A control method for a hybrid vehicle, comprising: controlling the mechanical power from the electric motor to regenerate the electric motor. A method for controlling a hybrid vehicle having an engine and an electric motor as a drive source,
The hybrid vehicle
An input shaft that is connected to the electric motor and can be switched between engaged and disengaged with the engine output shaft, and mechanical power from the engine output shaft and the electric motor is transmitted by the input shaft. A transmission capable of engaging any one of a plurality of shift speeds to engage the input shaft and the drive wheel, and the transmission travels forward according to the rotation direction of the electric motor. Or one that can be switched to reverse running,
A mechanical oil pump capable of supplying lubricating oil to the transmission only in accordance with rotation in one direction of a drive shaft that rotates based on mechanical power from the electric motor, the drive shaft being driven forward by the transmission When it is switched to traveling when it is switched to the direction of supplying lubricating oil, when the transmission is switched to reverse traveling, it is rotated in the opposite direction not supplying lubricant oil,
Control means for controlling the vehicle speed of the vehicle when the transmission is switched to reverse travel according to the rotation direction of the electric motor and the oil pump cannot supply the lubricating oil to the transmission. Prepared
The control means includes
Reducing vehicle speed by differential rotation between the engine and the input shaft generated by performing control for stopping the engine or control for engaging the stopped engine with the input shaft;
A control method for a hybrid vehicle, comprising: controlling the mechanical power from the electric motor to regenerate the electric motor.   The method for controlling a hybrid vehicle according to claim 6 or 7, wherein the control means further includes a step of applying a brake for mechanically stopping the drive wheels.

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