JP5012400B2 - Driving force transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force transmitting device capable of securing accurate temperature detection at restarting, and performing more accurate driving force transmission control. <P>SOLUTION: A water temperature sensor 19 for detecting a cooling water temperature Tw of an engine 2 is connected to an ECU 10, and a cooling water temperature detection means comprises the ECU 10 and the water temperature sensor 19. At restarting, the ECU 10 corrects an outside air temperature Tmp detected by a temperature sensor based on an elapsed time t from an engine stop and a difference value &Delta;T between the cooling water temperature Tw detected by the water temperature sensor 19 and the outside air temperature Tmp detected by the temperature sensor. Subsequently, the ECU 10 executes the estimation calculation of an initial temperature of torque coupling by using the corrected outside air temperature Tmp'. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a driving force transmission device.

  Conventionally, a torque coupling capable of transmitting the torque capacity, that is, a torque coupling capable of changing the torque transmission capacity based on the engaging force of a clutch mechanism provided in the middle of a drive system that transmits the engine driving force to each wheel has been provided. There is a driving force transmission device. For example, in the driving force transmission device described in Patent Document 1, an electromagnetic clutch (pilot clutch) is employed for the clutch mechanism. Then, by controlling the energization amount to the electromagnetic clutch, it is possible to adjust the engagement force and arbitrarily change the torque transmission capacity, that is, to execute the driving force transmission control.

  In such a driving force transmission device, determination of a control target value in consideration of various temperature conditions and correction thereof are common. For example, in Patent Document 2, in a vehicle in which the driving force distribution between the main driving wheel and the auxiliary driving wheel can be changed by changing the torque transmission capacity, the detected outside air temperature is equal to or lower than a predetermined temperature. Discloses a configuration in which the traveling road surface is estimated to be a low μ road (such as a frozen road), and the control target value is determined so as to transmit more driving force to the auxiliary driving wheel side.

  Furthermore, in torque coupling using a clutch mechanism, there is a problem that the engagement force of the clutch mechanism changes depending on the temperature (the temperature of the friction member or the lubricating oil constituting the clutch mechanism) (for example, patents). Reference 3 (FIG. 6)). In order to deal with this, a method of detecting the temperature of the torque coupling and correcting the control target of the torque transmission capacity based on the detected temperature has been considered.

In Patent Document 4, when performing control based on such torque coupling temperature, the torque sensor is used to simplify the configuration by eliminating the temperature sensor and based on the transmitted energy balance per unit time in the torque coupling. A configuration for estimating the temperature of the coupling is disclosed.
JP 2002-61677 A JP-A-11-59216 JP 2004-189067 A JP 2002-166737 A

  However, in general, state information that is the basis of various controls in consideration of such temperature conditions, that is, temperature information such as outside air temperature and torque coupling temperature, is when the engine is stopped (when the ignition (hereinafter referred to as “IG”) is off). Is not detected (including estimation and update). That is, when the engine is restarted (when the IG is on), there is a problem that the detected value is not necessarily an accurate value due to the loss of continuity.

  For example, the temperature sensor used to detect the outside air temperature is generally arranged in the engine room, but the engine room is basically just after the engine stops when the inflow of running wind or ventilation by the radiator fan stops. It has a structure where the exhaust heat is easily stored. For this reason, when the engine is restarted in a relatively short time after the engine is stopped, a value higher than the actual outside air temperature may be detected. Further, as in the conventional example, the value estimated at the time of the previous calculation is stored as the previous value, and the temperature estimation is periodically performed by adding the temperature change per cycle to the previous value. There is a possibility that the temperature change from the stop to the restart will not be reflected in the estimated value and will be an error as it is.

  Therefore, in the conventional configuration, since the temperature information detected at the time of restart is not always accurate, it is difficult to execute highly accurate driving force transmission control immediately after the engine restart. In addition, there was room for improvement.

  The present invention has been made to solve the above-described problems, and its purpose is to ensure accurate temperature detection at the time of restart and enable driving force transmission control with higher accuracy. It is to provide a transmission device.

In order to solve the above problems, the invention according to claim 1 is capable of changing the torque transmission capacity based on the engagement force of a clutch mechanism provided in the middle of a drive system that transmits the drive force of the engine to each wheel. A torque coupling; and a control means for controlling the torque transmission capacity through adjustment of the engagement force, and an outside air temperature detecting means for detecting an outside air temperature of the vehicle, wherein the control means includes the detected outside air temperature. In the driving force transmission device that estimates the torque coupling temperature based on the estimated temperature and corrects the control target value of the torque transmission capacity based on the estimated temperature, the outside air temperature detecting means includes the engine A temperature sensor disposed in the engine room, the cooling water temperature detecting means for detecting the cooling water temperature of the engine; Rutotomoni a measuring means for measuring an elapsed time until the restart, the cooling water temperature and the elapsed time until the restart from the difference value and the stop of the engine with the ambient temperature, and the outside air temperature correction value associated from provided with a map, wherein, during the restart, the detected difference value of the cooling water temperature and the detected outside air temperature, and on the basis of the measured elapsed time, the map The gist of the invention is to calculate an outside air temperature correction value by a calculation using, and to correct the outside air temperature value used for temperature estimation of the torque coupling by the calculated outside air temperature correction value .

According to a second aspect of the present invention, the control means stores the estimated temperature of the torque coupling as a previous value, and based on the stored previous value, the temperature of the torque coupling for each predetermined period. In the restart, the initial temperature of the torque coupling is determined based on the difference value between the stored previous value and the corrected outside air temperature and the elapsed time. And updating the previous value used for the temperature estimation based on the initial temperature .
According to a third aspect of the present invention, there is provided a torque coupling capable of changing a torque transmission capacity based on an engagement force of a clutch mechanism provided in the middle of a drive system that transmits an engine drive force to each wheel; Control means for controlling the torque transmission capacity through adjustment, and an outside air temperature detection means for detecting the outside air temperature of the vehicle. The control means determines the control target value of the torque transmission capacity by the detection. In the driving force transmission device using the outside air temperature, the outside air temperature detecting means includes a temperature sensor disposed in an engine room in which the engine is accommodated, and the cooling water temperature of the engine comprising a coolant temperature detecting means for detecting, and measuring means for measuring an elapsed time until the restart from the stop of the engine Rutotomoni, the outer and the cooling water temperature Comprising the elapsed time until the restart from the difference value and the stop of the engine temperature Prefecture, a map in which the outside air temperature correction value associated, wherein, during the restart, the detected cool Based on the difference value between the water temperature and the detected outside air temperature and the measured elapsed time, an outside air temperature correction value is calculated by calculation using the map, and the control is performed based on the calculated outside air temperature correction value. The gist is to correct the value of the outside air temperature used to determine the target value .
That is, due to the temperature rise in the engine room due to the engine stop, the value of the outside air temperature detected by the temperature sensor at the time of restart becomes higher than the actual outside air temperature, the temperature rise is due to the heat released by the engine, In other words, this is due to heat exchange between the engine and the air in the engine room. In other words, if the coolant temperature is used as a surrogate variable for the engine temperature, the amount of heat transferred from the engine to the air in the engine room increases as the temperature difference (difference value) between the coolant temperature and the outside air temperature increases. And the longer the elapsed time from the engine stop, the closer the temperature in the engine room approaches the actual outside air temperature (outside temperature of the engine room). That is, based on these difference values and elapsed time, a value (outside air temperature correction value) to be corrected for the outside air temperature detected by the temperature sensor arranged in the engine room can be calculated at the time of restart.

  Therefore, according to each of the above-described configurations, it is possible to accurately detect the outside air temperature even at the time of restart, and as a result, it is possible to execute more accurate driving force transmission control immediately after the restart. And like the structure of Claim 1 and Claim 2, it applies to the structure which estimates the torque coupling temperature based on the said detected outdoor temperature, and performs drive transmission control according to the estimated value outside Thus, a more remarkable effect can be obtained. In particular, in the configuration of claim 2, since the continuity lost due to the engine stop is complemented, the effect becomes more remarkable.

  ADVANTAGE OF THE INVENTION According to this invention, the accurate temperature detection at the time of restart is ensured, and the driving force transmission device which enables more accurate driving force transmission control can be provided.

Hereinafter, an embodiment in which the present invention is embodied in a driving force transmission device mounted on a four-wheel drive vehicle will be described with reference to the drawings.
As shown in FIG. 1, the vehicle 1 is a four-wheel drive vehicle based on a front wheel drive vehicle, and a pair of front axles 4 are connected to a transaxle 3 assembled on one side of the engine 2. Further, a propeller shaft 5 is connected to the transaxle 3 together with the front axles 4, and the propeller shaft 5 is connected to a pair of rear axles 8 via a rear differential 7. The driving force of the engine 2 is transmitted to the front wheels 6f through these front axles 4, and is also transmitted to the rear wheels 6r through the propeller shafts 5 and the respective rear axles 8.

  That is, in this embodiment, the transaxle 3, the front axle 4, the propeller shaft 5, the rear differential 7 and the rear axle 8 constitute a drive system that transmits the driving force of the engine 2 to each wheel 6.

  In the present embodiment, a torque capacity that can be transmitted, that is, a torque transmission capacity, is set between the propeller shaft 5 and the rear differential 7 constituting the drive system as described above based on the engagement force of the clutch mechanism. A changeable torque coupling 9 is interposed, and the operation of the torque coupling 9 is controlled by an ECU 10 as control means.

  Specifically, the torque coupling 9 of the present embodiment includes an electromagnetic clutch 12 whose frictional engagement force changes according to the amount of current supplied to the electromagnetic coil, and the driving force based on the frictional engagement force is propeller. Transmission from the shaft 5 to the rear differential 7 is performed. The ECU 10 is configured to control the torque transmission capacity of the torque coupling 9, that is, to execute the driving force transmission control, by adjusting the friction engagement force of the electromagnetic clutch 12 through power supply.

  That is, in the present embodiment, the torque coupling 9 and the ECU 10 constitute a driving force transmission device. And the vehicle 1 of this embodiment changes the driving force transmitted from the propeller shaft 5 to the rear differential 7 by this driving force transmission device, so that the driving force between the front wheel 6f and the rear wheel 6r is changed. The distribution can be changed continuously.

  More specifically, the accelerator opening sensor 13 and the wheel speed sensors 14a to 14d are connected to the ECU 10 of the present embodiment. The ECU 10 determines the accelerator opening Ra and the vehicle speed V based on the output signals of these sensors. , And a wheel speed difference Wdf between the front wheel 6f and the rear wheel 6r is detected. In addition, the outside air temperature Tmp detected by the temperature sensor 15 is input to the ECU 10 of the present embodiment. In the present embodiment, an air conditioner temperature sensor disposed in the engine room 16 is used as the temperature sensor 15 that constitutes the outside air temperature detecting means together with the ECU 10. Then, the ECU 10 calculates a control target value (target torque τ *) of the torque transmission capacity based on the vehicle speed V, the accelerator opening degree Ra, and the wheel speed difference Wdf (and the outside air temperature Tmp).

  In addition, the ECU 10 of the present embodiment is configured so that the torque coupling 9 can cope with the change in the clutch mechanism engagement force caused by the temperature change as described above, that is, the fluctuation of the torque transmission capacity accompanying the temperature change of the torque coupling 9. (Specifically, the temperature of each friction member of the electromagnetic clutch 12 and the temperature of the lubricating oil interposed therebetween). Then, based on the estimated torque coupling temperature (TC temperature) Ttc, a target which is a control target value of the torque transmission capacity is ensured to perform stable driving force transmission control regardless of temperature change. Correct the torque τ *.

  That is, as shown in the flowchart of FIG. 2, the ECU 10 acquires each of the state quantities (step 101), calculates a target torque τ * that is a control target value of the torque transmission capacity (step 102), and then continues to torque. The estimation of the coupling temperature Ttc is executed (step 103). Then, the target torque τ * is corrected based on the estimated torque coupling temperature Ttc (step 104), and the drive current I corresponding to the corrected target torque τ ** is converted to the torque coupling 9 (electromagnetic clutch 12). Is energized (step 105). For details of the target torque correction control, see, for example, Patent Document 3 above.

  Here, the ECU 10 of the present embodiment executes an estimation of the torque coupling temperature Ttc (TC temperature estimation calculation) at predetermined intervals, and stores the estimated value in the memory 17 (see FIG. 1) as the previous value Ttc_b. . The next TC temperature estimation calculation is performed by adding a temperature change per cycle to the previous value Ttc_b based on the stored previous value Ttc_b.

  Specifically, as shown in the flowchart of FIG. 3, the ECU 10 first reads the previous value Ttc_b of the torque coupling temperature stored in the memory 17 as the storage means (step 201). The transmission energy En in the torque coupling 9 from the time of calculating the TC temperature to the time of calculating the current TC temperature is calculated (step 202). In the present embodiment, the calculation of the transmission energy En in this step 202 is performed based on the drive current I energized in the torque coupling 9 (electromagnetic clutch 12), the wheel speed difference Wdf between the front wheel 6f and the rear wheel 6r, and the like. (For example, refer to Patent Document 4).

  Next, the ECU 10 calculates the temperature change amount δtc of the torque coupling 9 in the most recent cycle based on the transmitted energy En (step 203), and the previous value read in step 201 is the temperature change amount δtc. By adding to Ttc_b, the current torque coupling temperature Ttc is calculated (Ttc = Ttc_b + δtc, step 204). Then, after the newly estimated torque coupling temperature Ttc is used for the target torque correction calculation (see FIG. 2, steps 102 and 103), etc., the new torque coupling temperature Ttc is stored in the memory 17. The previous value Ttc_b is updated (Ttc_b = Ttc, step 205).

(Temperature correction processing at restart)
Next, the temperature correction process at the time of restart in the driving force transmission device of the present embodiment will be described.

  As described above, detection of various state quantities (including estimation and update thereof) is not normally performed when the engine is stopped (when IG is off). Therefore, in the case of temperature information such as the outside air temperature Tmp and the torque coupling temperature Ttc that changes every moment, the value detected when the engine is restarted (when the IG is on) is lost due to the loss of continuity. There is a problem that it is not always an accurate value.

  In consideration of this point, the ECU 10 of the present embodiment executes correction processing for ensuring the accuracy of various temperature information used for driving force transmission control when the engine 2 is restarted (when the IG is on). To do. As a result, accurate temperature detection at the time of restart is ensured, and more accurate driving force transmission control is possible.

  Specifically, at the time of restart, the ECU 10 of the present embodiment first corrects the outside air temperature Tmp detected by the temperature sensor 15 and the previous value Ttc_b stored in the memory 17 that is the basis of the TC temperature estimation calculation. Perform the update.

  That is, the transmission energy En input to the torque coupling 9 when the engine is stopped becomes “zero”, so that the torque coupling temperature Ttc gradually decreases with time (see FIG. 4). However, the value stored in the memory 17 as the previous value Ttc_b remains the value when the engine is stopped. For this reason, an incorrect torque coupling temperature Ttc is estimated by performing the TC temperature estimation calculation using this as an initial value during restart.

  Therefore, when the engine 2 is restarted, the ECU 10 of the present embodiment sets the torque coupling temperature Ttc at the time of engine stop, that is, the previous value Ttc_b stored in the memory 17, the outside temperature Tmp, and the elapsed time t from the engine stop. Based on this, the initial temperature Ttc_in of the torque coupling 9 is estimated. Note that the ECU 10 of the present embodiment has a timer 18 as a measuring means for measuring an elapsed time t from the engine stop. Then, the previous value Ttc_b stored in the memory 17 is updated with the estimated initial temperature Ttc_in.

  That is, as shown in FIG. 4, the torque coupling temperature Ttc is finally released to the ambient temperature of the torque coupling 9, that is, the outside air temperature Tmp by being released to the surrounding air over time. . The heat release rate depends on the difference value (temperature gradient) between the torque coupling temperature Ttc and the outside air temperature Tmp.

  That is, if the state quantity (heat capacity, thermal conductivity, etc.) related to heat conduction other than the difference value between the torque coupling temperature Ttc and the outside air temperature Tmp is constant, the coefficient related to heat conduction including the difference value is expressed as “ If “K” is set, the change with time can be expressed by the following equation (1).

f (t) = K × exp (-t / s) (1)
Therefore, by using this equation (1), based on the previous value Ttc_b stored in the memory 17, the outside air temperature Tmp, and the elapsed time t from the engine stop, the torque coupling temperature Ttc at the time of restart, that is, the initial value It is possible to estimate the temperature Ttc_in. In the present embodiment, the previous value Ttc_b stored in the memory 17 is updated with the initial temperature Ttc_in and used for the next TC temperature estimation calculation, thereby complementing the continuity lost due to the engine stop. ing.

  Further, as described above, in the present embodiment, the temperature sensor 15 that constitutes the outside air temperature detecting means is disposed in the engine room 16 in which the engine 2 is housed. As a result, a value higher than the actual outside air temperature may be detected.

  Therefore, in the present embodiment, the correction calculation of the outside air temperature Tmp detected by the temperature sensor 15 is executed prior to the estimation of the initial temperature Ttc_in of the torque coupling 9. The corrected outside air temperature Tmp ′ is used to estimate the initial temperature Ttc_in of the torque coupling.

  Specifically, as shown in FIG. 1, a water temperature sensor 19 for detecting the cooling water temperature Tw of the engine 2 is connected to the ECU 10 of the present embodiment, and the ECU 10 and the water temperature sensor 19 provide a cooling water temperature detecting means. It is configured. Then, at the time of restart, the ECU 10 determines the elapsed time t from the engine stop and the difference value ΔT between the cooling water temperature Tw detected by the water temperature sensor 19 and the outside air temperature Tmp detected by the temperature sensor 15. The value of the outside air temperature Tmp detected by the temperature sensor 15 is corrected.

  Specifically, the ECU 10 of the present embodiment includes a three-dimensional map in which the difference value ΔT between the cooling water temperature Tw and the outside air temperature Tmp, the elapsed time t from the engine stop, and the outside air temperature correction value Td are associated. (See FIG. 5). At the time of restart, the outside air temperature correction value Td is calculated by referring to the map 20 with the difference value ΔT and the elapsed time t calculated based on the detection value of each sensor, and the outside air temperature correction value Td is converted into the temperature. By subtracting from the outside air temperature Tmp detected by the sensor 15, the outside air temperature Tmp is corrected.

  That is, the temperature rise in the engine room 16 due to the engine stop is due to heat released by the engine 2, that is, due to heat exchange between the engine 2 and the air in the engine room 16. Therefore, by calculating the temperature change of the engine 2 from the engine stop to the restart, the temperature rise of the engine room 16, that is, the outside air temperature detected by the temperature sensor 15 disposed in the engine room 16 at the time of restart. A value to be corrected for Tmp, that is, an outside air temperature correction value Td can be calculated. And the time change of the engine temperature after the engine stop in which the air stays in the engine room 16 follows the above equation (1) as in the case of the temperature estimation of the torque coupling described above.

  That is, the cooling water temperature Tw is a surrogate variable of the engine temperature, and is transmitted from the engine 2 to the air in the engine room 16 as the temperature difference between the cooling water temperature Tw and the outside air temperature Tmp, that is, the difference value ΔT is larger. The amount of heat is large. Therefore, the outside air temperature correction value Td becomes large. Further, as the amount of heat is released to the outside as time passes, the temperature in the engine room 16 approaches the actual outside air temperature. Accordingly, the longer the elapsed time t, the smaller the outside air temperature correction value Td. The map 20 shown in FIG. 5 stores the relationship between the difference value ΔT, the elapsed time t, and the outside air temperature correction value Td in the form of a three-dimensional map. More specifically, the map 20 of this embodiment is subjected to optimization processing based on actual measurement values.

Next, a temperature correction processing procedure at restart in the present embodiment configured as described above will be described.
As shown in the flowchart of FIG. 6, the ECU 10 first determines whether or not it is immediately after the IG is turned on, that is, at the time of restart (step 301). If it is immediately after the IG is turned on (step 301: YES), the outside air temperature correction calculation for correcting the outside air temperature Tmp detected by the temperature sensor 15 is executed (step 302).

  In this case, the range of “immediately after the IG is turned on (at the time of restart)” is until the engine room 16 in which the temperature sensor 15 is arranged is in a state where sufficient ventilation is ensured or until the state is reached. It is desirable to set a predetermined time. Specifically, for example, it may be set until the vehicle speed at which sufficient inflow of traveling wind can be expected, or until a predetermined time has passed to such an extent that the ventilation effect by the radiator fan can be expected.

  In the outside air temperature correction calculation in step 302, as shown in the flowchart of FIG. 7, the ECU 10 first sets the outside air temperature Tmp, the cooling water temperature Tw, and the elapsed time from the engine stop as state quantities used for the outside air temperature correction calculation. t is acquired (step 401). Next, the ECU 10 calculates a difference value ΔT between the coolant temperature Tw and the outside air temperature Tmp (ΔT = Tw−Tmp, step 402), and executes map calculation using the difference value ΔT and the elapsed time t (FIG. 5), the outside air temperature correction value Td is calculated (step 403). Then, the outside air temperature correction value Td is subtracted from the outside air temperature Tmp detected by the temperature sensor 15 to correct the outside air temperature Tmp (Tmp ′ = Tmp−Td, step 404).

  When the outside air temperature correction calculation in step 302 is executed in this way, the ECU 10 subsequently executes an estimation calculation of the initial torque coupling initial temperature Ttc_in using the corrected outside air temperature Tmp ′ (TC initial temperature). Estimation calculation, step 303). Then, the previous value Ttc_b stored in the memory 17 serving as a basis for the subsequent TC temperature estimation calculation is updated by the initial temperature Ttc_in (TC temperature previous value update: Ttc_b = Ttc_in, step 304).

As described above, according to the present embodiment, the following operations and effects can be obtained.
(1) When the engine 2 is restarted (when the IG is on), the ECU 10 corrects the outside air temperature Tmp detected by the temperature sensor 15 and the previous value stored in the memory 17 that is the basis of the TC temperature estimation calculation. Update Ttc_b.

  That is, normally, when the engine is stopped (when IG is off), detection of various state quantities (including estimation and update thereof) is not performed. Therefore, in the case of temperature information such as the outside air temperature Tmp and the torque coupling temperature Ttc that changes every moment, the value detected when the engine is restarted (when the IG is on) is lost due to the loss of continuity. It is not necessarily an accurate value. However, with the above configuration, it is possible to ensure accurate temperature detection at the time of restart by complementing the continuity lost due to the engine stop. As a result, more accurate driving force transmission control can be executed immediately after restarting.

  (2) When the engine 2 is restarted, the ECU 10 estimates the initial temperature Ttc_in of the torque coupling 9 based on the torque coupling temperature Ttc when the engine is stopped, the outside air temperature Tmp, and the elapsed time t after the engine is stopped. .

  That is, the torque coupling temperature Ttc is finally released to the ambient temperature of the torque coupling 9, that is, the outside air temperature Tmp, by being released to the surrounding air with time. The heat release rate depends on the difference value (temperature gradient) between the torque coupling temperature Ttc and the outside air temperature Tmp. Therefore, according to the said structure, the torque coupling temperature Ttc at the time of restart can be estimated correctly.

  (3) The ECU 10 executes the estimation of the torque coupling temperature Ttc (TC temperature estimation calculation) every predetermined cycle, stores the estimated value in the memory 17 as the previous value Ttc_b, and the stored previous value Ttc_b. The next TC temperature estimation calculation is executed by adding the temperature change in the latest one cycle to. Then, the ECU 10 updates the previous value Ttc_b stored in the memory 17 with the initial temperature Ttc_in estimated in (2) above.

According to the above configuration, the continuity lost due to the engine stop is complemented and the torque coupling temperature Ttc can be estimated more accurately.
(4) When the engine 2 is restarted, the ECU 10 corrects the outside air temperature Tmp detected by the temperature sensor 15 based on the difference value ΔT between the cooling water temperature Tw and the outside air temperature Tmp and the elapsed time t from the engine stop. .

  That is, due to the temperature rise of the engine room 16 due to the engine stop, the value of the outside air temperature Tmp detected by the temperature sensor 15 at the time of restart becomes higher than the actual outside air temperature, but the temperature rise is released by the engine 2. This is due to heat, that is, due to heat exchange between the engine 2 and the air in the engine room 16. In other words, if the coolant temperature Tw is used as a surrogate variable for the engine temperature, the temperature difference between the coolant temperature Tw and the outside air temperature Tmp, that is, the difference value ΔT increases, and is transmitted from the engine 2 to the air in the engine room 16. The amount of heat is large. As the elapsed time t from the engine stop increases, the temperature in the engine room 16 approaches the actual outside air temperature. That is, based on the difference value ΔT and the elapsed time t, a value (outside air temperature correction value Td) to be corrected for the outside air temperature Tmp detected by the temperature sensor 15 disposed in the engine room 16 at the time of restart is calculated. can do. Therefore, according to the above configuration, it is possible to accurately detect the outside air temperature even at the time of restart, and as a result, it is possible to execute more accurate driving force transmission control immediately after the restart. . In particular, a more remarkable effect can be obtained by applying to the configurations of (2) and (3) above in which the outside air temperature Tmp is used to estimate the torque coupling temperature Ttc.

In addition, you may change this embodiment as follows.
In the present embodiment, the torque coupling 9 is interposed between the propeller shaft 5 and the rear differential 7. However, the torque coupling 9 may be applied to those arranged at other locations constituting the drive system. .

  In this embodiment, in the configuration in which the present invention uses the outside air temperature Tmp to estimate the initial torque coupling initial temperature Ttc_in at the time of restart, the difference value ΔT between the coolant temperature Tw and the outside air temperature Tmp and the engine The invention is embodied in a configuration in which the outside air temperature Tmp is corrected based on the elapsed time t from the stop. However, the present invention is not limited to the initial temperature Ttc_in, but may be applied to a configuration in which the outside air temperature Tmp is used for estimating the torque coupling temperature Ttc. Further, not only the temperature estimation of the torque coupling but also the configuration (for example, Patent Document 2) that uses the outside air temperature Tmp to determine (or correct) the control target value of the torque transmission capacity at the time of such restart. A configuration in which the outside air temperature Tmp is corrected based on the difference value ΔT between the cooling water temperature Tw and the outside air temperature Tmp and the elapsed time t from the engine stop may be applied.

  -Moreover, it is good also as a structure which only estimates the initial temperature Ttc_in of the torque coupling at the time of restart about the thing by which the temperature sensor which comprises an outside temperature detection means is arrange | positioned other than an engine room.

  In the present embodiment, the clutch mechanism of the torque coupling 9 is the electromagnetic clutch 12 that is an electromagnetic friction clutch. However, the present invention is not limited to this, and the present invention may be applied to one using a hydraulic clutch mechanism or one using a clutch mechanism other than a friction clutch.

The schematic block diagram of the vehicle by which a driving force distribution apparatus is mounted. The flowchart which shows the process sequence of the correction | amendment control of the target torque based on torque coupling temperature. The flowchart which shows the process sequence of a torque coupling temperature estimation calculation. The graph which shows the temperature change of the torque coupling with time passage after an engine stop. The schematic block diagram of the map with which the difference value of engine cooling water temperature and external temperature, the elapsed time from engine stop, and external temperature correction value were linked | related. The flowchart which shows the process sequence of initial temperature estimation of a torque coupling, and last time value update. The flowchart which shows the process sequence of the external temperature correction control at the time of restart.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 3 ... Transaxle, 4 ... Front axle, 5 ... Propeller shaft, 6 ... Wheel, 6f ... Front wheel, 6r ... Rear wheel, 7 ... Rear differential, 8 ... Rear axle, 10 ... ECU, 12 ... Electromagnetic clutch, 15 ... Temperature sensor, 16 ... Engine room, 17 ... Memory, 18 ... Timer, 19 ... Water temperature sensor, Tmp, Tmp '... Outside air temperature, Tw ... Cooling water temperature, Δt ... Differential value, Td ... Outside air temperature correction Value, Ttc: Torque coupling temperature, Ttc_b: Previous value, Ttc_in: Initial temperature, τ *, τ **: Target torque, t: Elapsed time.

Claims (3)

A torque coupling capable of changing the torque transmission capacity based on an engagement force of a clutch mechanism provided in the middle of a drive system that transmits engine driving force to each wheel, and controlling the torque transmission capacity through adjustment of the engagement force. And an outside air temperature detecting means for detecting an outside air temperature of the vehicle. The control means estimates the temperature of the torque coupling based on the detected outside air temperature, and sets the estimated temperature to the estimated temperature. In the driving force transmission device that corrects the control target value of the torque transmission capacity based on:
The outside air temperature detecting means includes a temperature sensor arranged in an engine room in which the engine is accommodated,
Rutotomoni comprising a coolant temperature detecting means for detecting a cooling water temperature of the engine, and a measuring means for measuring an elapsed time until the restart from the stop of the engine,
A difference value between the cooling water temperature and the outside air temperature, an elapsed time from stop to restart of the engine, and a map in which an outside air temperature correction value is associated,
Wherein, during the restart, the outer said detected difference value of the cooling water temperature and the detected outside air temperature, and on the basis of the measured elapsed time, by computation using the map A driving force transmission device characterized in that an air temperature correction value is calculated, and an external air temperature value used for temperature estimation of the torque coupling is corrected by the calculated external air temperature correction value . The driving force transmission device according to claim 1,
The control means stores the estimated torque coupling temperature as a previous value, and executes the torque coupling temperature estimation for each predetermined period based on the stored previous value,
At the time of restart, the initial temperature of the torque coupling is estimated based on the difference value between the stored previous value and the corrected outside air temperature, and the elapsed time, and the initial temperature is used to estimate the initial temperature. A driving force transmission device characterized by updating a previous value used for temperature estimation. The torque transmission capacity is controlled through adjustment of the engagement force, and a torque coupling capable of changing the torque transmission capacity based on an engagement force of a clutch mechanism provided in the middle of a drive system that transmits the engine drive force to each wheel. A control means, and an outside air temperature detecting means for detecting an outside air temperature of the vehicle, and a driving force transmission in which the detected outside air temperature is used for determining a control target value of the torque transmission capacity by the control means. In the device
The outside air temperature detecting means includes a temperature sensor arranged in an engine room in which the engine is accommodated,
Rutotomoni comprising a coolant temperature detecting means for detecting a cooling water temperature of the engine, and a measuring means for measuring an elapsed time until the restart from the stop of the engine,
A difference value between the cooling water temperature and the outside air temperature, an elapsed time from stop to restart of the engine, and a map in which an outside air temperature correction value is associated,
Wherein, during the restart, the outer said detected difference value of the cooling water temperature and the detected outside air temperature, and on the basis of the measured elapsed time, by computation using the map A driving force transmission device that calculates an air temperature correction value, and corrects the value of the external air temperature used to determine the control target value by the calculated external air temperature correction value .

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