JP5073606B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device including a distribution ratio control mechanism capable of changing a distribution ratio of driving force transmitted between left and right wheels or front and rear wheels of a vehicle.

  Conventionally, provided with a distribution ratio control mechanism that can vary the distribution ratio of the driving force transmitted between the left and right wheels of the vehicle or between the front and rear wheels, and a vacancy determination mechanism that determines the vacancy state of the engine, A power transmission device is known in which the distribution ratio control mechanism stops distribution ratio control when it is determined to be in an empty state by the empty determination mechanism (see, for example, Patent Document 1).

  The one in Patent Document 1 includes an acceleration detection mechanism that detects a longitudinal acceleration and a rotation speed change amount detection mechanism that detects a change amount of an engine speed, and the idling determination mechanism is detected by the acceleration detection mechanism. If the vehicle is determined to be traveling at a constant speed or decelerating from the value, and the amount of change in engine speed obtained by the rotational speed change detection mechanism is greater than or equal to a predetermined value, It is determined to be in a normal state.

Then, when it is determined that the engine is in the idling state by the idling determination mechanism, the distribution ratio control of the allocation ratio control mechanism is stopped to prevent the driver from feeling uncomfortable with the vehicle behavior. Yes.
Japanese Patent No. 3326081

  Conventionally, it has been considered that the idling state of the engine occurs only during constant speed traveling or decelerating traveling. However, the inventor of the present application is shifting gears and depressing the accelerator pedal even during acceleration traveling. It has been found that an engine vacancy condition occurs. However, in the conventional power transmission device, since it is determined whether or not the vehicle is in an idle state from the amount of change in the acceleration and the engine speed, it is not possible to determine the empty state during acceleration traveling.

  In view of the above points, an object of the present invention is to provide a power transmission device that can also determine an idling state during acceleration traveling and transmit an appropriate driving force to wheels.

  In order to achieve the above object, the present invention provides a distribution ratio control mechanism capable of changing a distribution ratio of driving force transmitted between left and right wheels or front and rear wheels of a vehicle, and an empty state for determining an engine idling state. A power ratio determining mechanism for stopping the distribution ratio control when the engine is determined to be in an empty state by the idling determination mechanism. A rotation speed change amount detecting mechanism for detecting a shift, a shifting determination mechanism for determining whether or not the transmission is shifting, and an accelerator pedal detecting mechanism for detecting that the accelerator pedal is depressed. The amount of change in the engine speed detected by the engine speed change detection mechanism is greater than or equal to a predetermined value, and the shift determination mechanism determines that the shift is being determined by the shift determination mechanism. Detect that you are stepping on Occasionally, and judging that the engine is racing state.

  According to the present invention, the idling determination mechanism determines that the amount of change in the engine speed detected by the speed change amount detection mechanism is equal to or greater than a predetermined value, and that the speed change determination mechanism determines that the speed is being changed. When the detection mechanism detects that the driver is stepping on the accelerator pedal, it is determined that the engine is in an idle state. Thus, even when the vehicle is accelerating, it is possible to determine the idle state, and to transmit an appropriate driving force to the wheels without giving the driver a feeling of strangeness in the vehicle behavior. .

As during shifting determination mechanism, which calculates the gear ratio from the engine speed and the drive wheel rotation speed, by comparing the calculated gear ratio and the gear ratio of the gears of the transmission to determine whether or not shift change Ru can be configured to. Moving force transmission apparatus includes an engine rotational speed detecting mechanism for detecting the rotational speed of the engine, and a drive wheel rotation speed detecting mechanism for detecting the rotational speed of the drive wheels.

  By the way, when the vehicle is started, when the clutch is engaged after the engine speed is increased, the idling determination mechanism determines that the idling is over, and the distribution ratio control by the distribution ratio control mechanism stops. There is a possibility that the starting performance is deteriorated. In this case, the power transmission device according to the present invention is provided with a vehicle speed measurement mechanism for measuring the vehicle speed, and the idling determination mechanism is in an idling state when the vehicle speed measured by the vehicle speed measurement mechanism is equal to or higher than a predetermined speed. If it is configured so as to determine whether or not the vehicle is in a starting state, no determination is made at the time of starting the vehicle, and a decrease in the starting performance can be prevented.

  Further, in the case of a manual transmission, it is conceivable that the clutch is disengaged for shifting while the driver is stepping on the accelerator pedal during acceleration traveling. At this time, since the engine is in an idling state, in the case of a manual transmission, an idling state during acceleration traveling is more likely to occur than in an automatic transmission. Therefore, the power transmission device of the present invention is particularly effective when used in a vehicle in which the transmission is a manual transmission.

  A power transmission device according to a first embodiment of the present invention will be described with reference to FIGS. The power transmission device of the first embodiment is provided in a front wheel drive vehicle including a manual transmission, and includes a differential mechanism D and a distribution ratio control mechanism T as shown in FIG.

  The differential mechanism D includes a differential case Da and a double pinion planetary gear P1 accommodated in the differential case Da. The planetary gear P1 meshes with the inner pinion 13 and the carrier 14 that carries the ring gear 11 that is rotatably supported in the differential case Da, the outer pinion 12 that meshes with the ring gear 11, and the inner pinion 13 that meshes with the outer pinion 12. And the sun gear 15.

  Outer teeth 11a are formed on the outer peripheral surface of the ring gear 11, and the outer teeth 11a mesh with an output gear 22 provided on an output shaft 21 of a manual transmission (not shown), and the ring gear 11 functions as an input element. The carrier 14 is connected to the right axle 3R that transmits driving force to the right front wheel WFR and functions as an output element on the right front wheel WFR side, and the sun gear 15 is connected to the left axle 3R that transmits driving force to the left front wheel WFL and is left Functions as an output element on the front wheel WFL side.

  The distribution ratio control mechanism T includes a case Ta, a planetary gear P2 accommodated in the case Ta, and a speed increasing brake B1 and a speed reducing brake B2 made up of a wet hydraulic multi-plate clutch. In the case Ta, the left axle 3L penetrates rotatably.

  The planetary gear P2 is rotatably supported on the left axle 3L, is rotated by the first sun gear 41 that rotates integrally with the carrier 14 of the planetary gear P1, the second sun gear 42 that rotates integrally with the left axle 3L, and is rotatable by the left axle 3L. The third sun gear 43 that is supported on the case Ta and is freely fixed to the case Ta via the speed increasing brake B1, and the first tooth portion 44a and the second tooth portion 44b that mesh with the first to third sun gears 41, 42, and 43, respectively. And a carrier 45 carrying a triple pinion 44 having a third tooth portion 44c. The carrier 45 can be fixed to the case Ta via the deceleration brake B2.

  The number of teeth of the first sun gear 41 is st1, the number of teeth of the second sun gear 42 is st2, the number of teeth of the third sun gear 43 is st3, the number of teeth of the first tooth portion 44a is pt1, and the number of teeth of the second tooth portion 44b pt2. When the number of teeth of the third tooth portion 44c is pt3, the number of teeth is expressed as follows: st1> st2> st3, pt1 <pt2 <pt3, (pt1 / st1) <(pt2 / st2) <(pt3 / st3) It is set to satisfy.

When the brake B2 for deceleration is engaged and the carrier 45 of the planetary gear P2 is fixed to the case Ta, the engagement between the second sun gear 42 and the second tooth portion 44b of the triple pinion 44, and the first tooth portion of the triple pinion 44 Due to the meshing of 44a and the first sun gear 41, the driving force of the left axle 3L is transmitted to the carrier 14 of the differential mechanism D connected to the right axle 3R. At this time, the relationship of the following equation (1) is established between the rotational speed NL of the left front wheel WFL and the rotational speed NR of the right front wheel WFR.
NL = (st1 × pt2) / (pt1 × st2) × NR (1)

  As described above, the number of teeth st1 of the first sun gear 41, the number of teeth st2 of the second sun gear 42, the number of teeth pt1 of the first tooth portion 44a, and the number of teeth pt2 of the second tooth portion 44b are (pt1 / st1) <( Since it is set so as to satisfy the relationship of pt2 / st2), NL> NR.

When the speed increasing brake B1 is engaged and the third sun gear 43 of the planetary gear P2 is fixed to the case Ta, the rotational speed NR of the right front wheel WFR is expressed by the following equation (2) with respect to the rotational speed NL of the left front wheel WFL. Therefore, NL <NR.
NR / NL = (1- (st3 / pt3) (pt1 / st1)) / (1- (st3 / pt3) (pt2 / st2)) (2)

  Both the brakes B1 and B2 are controlled in engagement force through a hydraulic circuit using a pressure control valve 61 and electromagnetic valves 62 and 63 controlled by the electronic control unit 5. The electronic control unit 5 receives a vehicle speed and a steering angle. The electronic control unit 5 obtains an appropriate distribution ratio of the driving force between the left front wheel WFL and the right front wheel WFR based on the input vehicle speed and steering angle. Distribution ratio control is performed to control the pressure control valve 61 and the electromagnetic valves 62 and 63 so that the obtained distribution ratio is obtained.

  As shown in FIG. 2, the power transmission device of the first embodiment includes an engine speed detection mechanism 71 that detects the engine speed, and driving wheel rotation that detects the rotation speed of the front wheels WFL and WFR that are driving wheels. A number detection mechanism 72, a vehicle speed measurement mechanism 73 for measuring the vehicle speed, and an accelerator pedal detection mechanism 74 for detecting that the accelerator pedal is depressed.

  The engine speed detected by the engine speed detection mechanism 71 is input to the electronic control unit 5, and the electronic control unit 5 executes a change amount calculation process 51 for obtaining a change amount of the engine speed from the input engine speed. . That is, in the power transmission device of the first embodiment, the engine speed detection mechanism 71 and the change amount calculation process 51 of the electronic control unit 5 constitute a rotation speed change amount detection mechanism.

  Further, the front wheel rotational speed detected by the drive wheel rotational speed detection mechanism 72 is input to the electronic control unit 5, and the electronic control unit 5 performs an average rotational speed calculation process 52 for calculating an average rotational speed from the input front wheel rotational speed. Execute.

  Next, the operation of the power transmission device of the first embodiment will be described. When the vehicle is traveling straight ahead, the electronic control unit 5 closes the electromagnetic valves 62 and 63 and disengages both the brakes B1 and B2. As a result, the carrier 45 and the third sun gear 43 of the distribution ratio control mechanism T can freely rotate without being restrained by the brakes B1 and B2, and the left axle 3L, the right axle 3R, the carrier 14 of the differential mechanism D, and the distribution ratio control mechanism. All T carriers 45 rotate together. Therefore, the driving force of the engine is evenly distributed from the differential mechanism D to the left and right front wheels WFL, WFR.

  When the vehicle is turning right, the electronic control unit 5 opens the electromagnetic valve 63 and supplies hydraulic oil to engage the deceleration brake B2 to fix the carrier 45 of the planetary gear P2 to the case Ta. At this time, the relationship of the above formula (1) is established between the rotational speed NL of the left front wheel WFL and the rotational speed NR of the right front wheel WFR, and NL> NR.

  Accordingly, during a right turn, the driving force of the right front wheel WFR that is the inner turning wheel decreases with respect to the driving force of the left front wheel WFL that is the outer turning wheel, and the vehicle can smoothly turn right. Incidentally, if the hydraulic pressure is controlled by the pressure control valve 61 to appropriately adjust the engaging force of the deceleration brake B2, the difference between NL and NR can be adjusted according to the change in the engaging force of the deceleration brake B2. .

  When the vehicle is turning left, the electronic control unit 5 opens the electromagnetic valve 62 and supplies hydraulic oil to engage the speed increasing brake B1 to fix the third sun gear 43 of the planetary gear P2 to the case Ta. . At this time, the rotational speed NR of the right front wheel WFR is increased with respect to the rotational speed NL of the left front wheel WFL according to the relationship of the above expression (2), so that NL <NR.

  Accordingly, when turning left, the driving force of the right front wheel WFR, which is the outer turning wheel, increases with respect to the driving force of the left front wheel WFL, which is the inner turning wheel, and the vehicle can smoothly turn left. In addition, by controlling the hydraulic pressure with the pressure control valve 61 and appropriately adjusting the engagement force of the acceleration brake B1, the engagement force of the acceleration brake B1 can be changed to adjust the amount of increase in NR relative to NL. it can.

  By the way, in the distribution ratio control mechanism T that controls the driving force distribution ratio based on the amount of change in the engine speed, the driver depresses the accelerator pedal in a state where the clutch is disengaged and the engine rotation is not transmitted to the axle. If the amount of change in the engine speed is greater than or equal to a predetermined value when the engine is in a vacant state, the distribution ratio control is executed even during coasting, giving the driver an uncomfortable feeling May exhibit behavior.

  Therefore, the electronic control unit 5 determines the engine idling state, and stops the distribution ratio control when the engine is idling. Hereinafter, the operation of the electronic control unit 5 will be described in detail.

  Referring to FIG. 3, first, in STEP 1, the electronic control unit 5 divides the engine speed detected by the engine speed detection mechanism 71 by the average speed of the front wheels determined in the average speed calculation process 52. The gear ratio calculation process 53 for obtaining the gear ratio is executed. Then, proceeding to STEP 2, the low-pass filter process 54 is executed to remove the noise of the gear ratio obtained in the gear ratio calculation process 53 of STEP 1.

  Then, the process proceeds to STEP 3, and a speed change determination process 55 is executed to compare the obtained gear ratio with the gear ratio of each gear stage of the manual transmission to determine whether or not the speed is being changed. Since the gear ratio of each gear stage is determined in advance, a gear ratio region corresponding to each gear stage is set in advance in consideration of errors and the like, and the obtained gear ratio corresponds to each gear stage in the shift determination process 55. If it does not correspond to any of the gear ratio regions, it is determined that the gear is being changed. That is, in the power transmission device of the first embodiment, a gear ratio calculation process 53, a low-pass filter process 54, and a shift determination process 55 constitute a shift determining mechanism.

  Then, the process proceeds to STEP 4 to execute an empty determination process 56 (an empty determination mechanism) for determining whether or not an empty state is present. In the following, this emptying determination process 56 will be described in detail with reference to FIG.

  In the idling determination process 56, first, in STEP 11, whether or not the vehicle speed measured by the vehicle speed measurement mechanism 73 is equal to or higher than a predetermined speed (for example, 30 km / h) before performing the idling determination. To check. When the vehicle speed is equal to or higher than the predetermined speed, the process proceeds to STEP 12 in order to perform the idling determination, and it is determined whether or not the change amount of the engine speed obtained in the change amount calculation processing 51 is equal to or higher than the predetermined value. To check. If the change amount of the engine speed is equal to or greater than the predetermined value, the process proceeds to STEP 13 and it is checked whether or not it is determined that the shift is being performed in the shift determination process 55 in STEP 3 (see FIG. 3).

  If it is determined that the shift is being performed in the shift determination process 55, the process proceeds to STEP 14, and it is checked whether or not the accelerator pedal detection mechanism 74 detects that the accelerator is stepped on. When the accelerator is stepped on, the process proceeds to STEP 15, where it is determined that the engine is in an idle state, and the distribution ratio control of the electronic control unit 5 is stopped.

  If the vehicle speed is lower than the predetermined speed in STEP 11, the process branches to STEP 16, and the distribution ratio control of the electronic control unit 5 is executed without performing the idling determination. By processing in this way, the driver does not perform the idling determination when starting the vehicle by engaging the clutch after raising the engine speed by depressing the accelerator pedal. The distribution ratio control is executed, so that it is possible to prevent the start performance of the vehicle from being deteriorated.

  If the change amount of the engine speed is less than the predetermined value in STEP 12, the process branches to STEP 16, and it is determined that the engine is not in the idle state, and the distribution ratio control of the electronic control unit 5 is executed. Even when the gear is not being shifted in STEP13, the process branches to STEP16 in the same manner, and it is determined that there is no idle state, and the distribution ratio control of the electronic control unit 5 is executed. Even in the case where the accelerator is not stepped on in STEP14, the process branches to STEP16 in the same manner, and it is determined that the vehicle is not in the idle state, and the distribution ratio control of the electronic control unit 5 is executed.

  According to the power transmission device of the first embodiment, the change amount of the engine speed calculated in the change amount calculation process 51 is equal to or greater than a predetermined value, and it is determined that the shift is being performed in the shift determination process 55, and the accelerator pedal is detected. When the mechanism 74 detects that the driver is stepping on the accelerator pedal, the idling determination processing 56 determines that the engine is idling and stops the distribution ratio control of the electronic control unit 5. To do. Thus, even when the vehicle is accelerating, it is possible to determine the idle state, and to transmit an appropriate driving force to the wheels without giving the driver a feeling of strangeness in the vehicle behavior. .

  Next, a second embodiment of the power transmission device of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the structure same as the thing of 1st Embodiment. The power transmission device of the second embodiment is provided in a four-wheel drive vehicle including an automatic transmission, and includes a rear wheel distribution ratio control mechanism T ′.

  The distribution ratio control mechanism T 'includes a case Ta', a pair of left and right planetary gears P3L and P3R housed in the case Ta ', and a pair of left and right brakes B3L and B3R made of a wet multi-plate clutch. The engagement forces of the brakes B3L and B3R are controlled by electromagnetic actuators 80L and 80R controlled by the electronic control unit 5.

  Planetary gears P3L and P3R include ring gears 81L and 81R that rotate integrally, carriers 83L and 83R that carry pinions 82L and 82R that mesh with ring gears 81L and 81R, and sun gears 84L and 84R that mesh with pinions 82L and 82R. .

  Ring gear 81L and ring gear 81R are connected by a shaft having bevel gear 85. A driving force of a propeller shaft 86 is transmitted to the bevel gear 85, and the front differential mechanism that meshes with the output gear 22 provided on the output shaft 21 of the automatic transmission and transmits the driving force to the front wheels WFL and WFR. The driving force of the automatic transmission is transmitted via D ′ and the transfer 87. Accordingly, the ring gears 81L and 81R function as input elements. The carriers 83L and 83R are connected to axles 3L 'and 3R' that transmit driving force to the rear wheels WRL and WRR, and function as output elements of the rear wheels WRL and WRR. The sun gears 84L and 84R can be fixed to the case Ta 'via the brakes B3L and B3R.

  When the brakes B3L and B3R are engaged by the electronic control unit 5, the sun gears 84L and 84R are fixed to the case Ta ', and the driving force of the propeller shaft 86 is applied to the ring gears 81L and 81R, the carriers 83L and 83R, and the axles 3L' and 3R. It is transmitted to the rear wheels WRL and WRR via '. When the brakes B3L and B3R are disengaged by the electronic control unit 5, the sun gears 84L and 84R are rotatable with respect to the case Ta ′, and the rotation of the ring gears 81L and 81R is not transmitted to the carriers 83L and 83R, and the propeller shaft The driving force 86 is not transmitted to the rear wheels WRL and WRR. The electronic control unit 5 can individually adjust the driving force transmitted to the left rear wheel WRL and the driving force transmitted to the right rear wheel WRR by individually controlling the engagement force of the brake B3L and the brake B3R. it can.

  The electronic control unit 5 receives vehicle travel information such as vehicle speed and steering angle, yaw rate from a yaw rate sensor (not shown), and lateral acceleration from a lateral acceleration sensor (not shown). Based on the input vehicle travel information, an appropriate distribution ratio of the driving force of the left rear wheel WRL and the right rear wheel WRR is obtained, and the distribution ratio for controlling the electromagnetic actuators 80L and 80R to be the obtained distribution ratio Execute control.

  Further, the power transmission device of the second embodiment is similar to that of the first embodiment, in which the engine rotational speed detection mechanism 71 and driving wheel rotational speed detection for detecting the rotational speeds of the front and rear wheels WFL, WFR, WRL, WRR are detected. A mechanism 72, a vehicle speed measurement mechanism 73, and an accelerator pedal detection mechanism 74 are provided. Then, the electronic control unit 5 executes a change amount calculation process 51 for obtaining a change amount of the engine speed from the input engine speed, and calculates an average speed from the input four-wheel speed. Process 52 is executed.

  Since the determination process of the engine empty state of the electronic control unit 5 of the second embodiment is the same as that of the first embodiment, the description thereof is omitted.

  According to the power transmission device of the second embodiment, it is possible to determine the idling state even when the vehicle is accelerating, and to perform appropriate driving without giving the driver a feeling of strangeness in the vehicle behavior. Power can be transmitted to the wheels.

  In the first embodiment, the power transmission device that varies the distribution ratio of the driving force of the left and right front wheels, and the power transmission device that varies the distribution ratio of the driving force of the left and right rear wheels is described in the second embodiment. The present invention can be similarly applied to a device that varies the distribution ratio of the driving force.

Explanatory drawing which shows 1st Embodiment of the power transmission device of this invention. The schematic diagram which shows the power transmission device of 1st Embodiment. The flowchart which shows the action | operation of the power transmission device of 1st Embodiment. The flowchart which shows the process of the idling determination mechanism of the power transmission device of 1st Embodiment. Explanatory drawing which shows 2nd Embodiment of the power transmission device of this invention.

Explanation of symbols

51... Change amount calculation process (rotational speed change amount detection mechanism) 53. Gear ratio calculation process (determination mechanism during shifting) 54. Low-pass filter process (determination mechanism during shifting) 55. Determining process during shifting (determination mechanism during shifting) ), 56... Ejection determination processing (emission determination mechanism), 71. Engine rotation speed detection mechanism (rotation speed change amount detection mechanism), 72... Drive wheel rotation speed detection mechanism, and 73. 74: Accelerator pedal detection mechanism, T, T ′: Distribution ratio control mechanism, WFL: Left front wheel, WFR: Right front wheel, WRL: Left rear wheel, WRR: Right rear wheel

Claims (3)

A distribution ratio control mechanism capable of changing the distribution ratio of the driving force transmitted between the left and right wheels or the front and rear wheels of the vehicle, and a vacancy determination mechanism that determines the vacancy state of the engine. In the power transmission device that stops the distribution ratio control, the distribution ratio control mechanism,
A rotation speed change amount detection mechanism for detecting a change amount of the engine speed;
A shifting determination mechanism that determines whether or not the transmission is shifting,
An accelerator pedal detection mechanism for detecting that the accelerator pedal is depressed;
An engine speed detection mechanism for detecting the engine speed;
A drive wheel rotational speed detection mechanism for detecting the rotational speed of the drive wheel ,
In the idling determination mechanism, the amount of change in the engine speed detected by the rotation speed change detection mechanism is equal to or greater than a predetermined value, the shift determination mechanism determines that a shift is in progress, and the accelerator pedal detection mechanism allows the driver to When it is detected that the pedal is being depressed, it is determined that the engine is in an idle state,
The shifting determination mechanism calculates a gear ratio from the engine rotation speed detected by the engine rotation speed detection mechanism and the drive wheel rotation speed detected by the drive wheel rotation speed detection mechanism, and the calculated gear ratio and each shift of the transmission are calculated. A power transmission device comprising: comparing a gear ratio of a stage to determine whether or not shifting is in progress . The power transmission device according to claim 1 , further comprising a vehicle speed measurement mechanism that measures a vehicle speed, wherein the idle speed determination mechanism is configured to detect an idle speed when the vehicle speed measured by the vehicle speed measurement mechanism is equal to or higher than a predetermined speed. It is determined whether it is a state, The power transmission device characterized by the above-mentioned. 3. The power transmission device according to claim 1 , wherein the transmission is a manual transmission. 4.

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