JP6476160B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle in which front wheels and rear wheels are driven by different driving sources.

  Conventionally, a vehicle in which front wheels and rear wheels are driven by different drive sources is known. For example, in the vehicle described in Patent Document 1, the engine torque is transmitted to the front wheels via the transmission, and the motor / generator torque is transmitted to the rear wheels without passing through the transmission. Has been.

  Further, in Patent Document 1, a clutch is provided in a torque transmission path from the engine to the transmission, and is transmitted from the motor / generator to the rear wheels when the clutch is released as the transmission is shifted. It is described that by increasing the torque, a decrease in the torque transmitted to the wheels at the time of shifting is suppressed.

JP 2001-158249 A

  By the way, the clutch generates heat at the time of friction engagement, and when the amount of generated heat is increased, wear is promoted and the engagement force is weakened, so that a desired torque may not be transmitted to the wheel. Further, if the clutch generates heat more than a predetermined heat generation amount, the clutch may be deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle capable of suppressing the temperature rise of the connecting / disconnecting means while ensuring the necessary power of the vehicle.

In order to achieve the above object, the invention described in claim 1
Power for driving a first wheel (for example, a front wheel Wf of a later-described embodiment) of a front wheel (for example, a front wheel Wf of a later-described embodiment) or a rear wheel (for example, a rear wheel Wr of a later-described embodiment). A first drive source (for example, a first drive source DS1 in an embodiment described later) and a transmission (for example, an implementation described later) provided on a power transmission path between the first drive source and the first wheel. Transmission TM) in the form, and provided on the power transmission path between the first drive source and the first wheel, and by releasing or fastening, the power transmission between the first drive source and the first wheel is cut off or A first drive device (for example, a front wheel drive device 11 of a later-described embodiment) including connection / disconnection means (for example, a clutch CL of a later-described embodiment) to be connected;
A second drive source (for example, a second drive source DS2 in an embodiment described later) that generates power for driving the other second wheel of the front wheel and the rear wheel (for example, a rear wheel Wr in an embodiment described later); A second drive device (for example, a rear wheel drive device 12 in an embodiment described later),
A vehicle (for example, a vehicle 10 according to an embodiment described later) including a control device (for example, a control device CTR according to an embodiment described later) that controls power distribution between the first drive device and the second drive device. And
Connection / disconnection means temperature acquisition means for acquiring the temperature of the connection / disconnection means (for example, a first temperature sensor TE1 in an embodiment described later);
Liquid medium temperature acquisition means (for example, second temperature sensor TE2 of the embodiment described later) for acquiring the temperature of the liquid medium (for example, ATF of the embodiment described later) that lubricates the transmission and the connection / disconnection means; In addition,
The control device includes:
Acquiring the temperature of the connection / disconnection means by the connection / disconnection means temperature acquisition means, and acquiring the temperature of the liquid medium by the liquid medium temperature acquisition means,
The power distribution amount of the first drive unit is reduced in accordance with either the temperature of the connection / disconnection means acquired by the connection / disconnection means temperature acquisition means or the temperature of the liquid medium acquired by the liquid medium temperature acquisition means. is allowed to change the power distribution in so that increasing the power distribution of the second driving device.

Moreover, in addition to the structure of Claim 1, the invention of Claim 2 is
The control device includes a first temperature difference (for example, a first temperature in an embodiment described later) that is a difference between the temperature of the connecting / disconnecting means and a predetermined first threshold temperature (for example, a clutch allowable limit temperature in an embodiment described later). Temperature difference Δ1) and a difference between a temperature of the liquid medium and a predetermined second threshold temperature (for example, ATF allowable limit temperature of an embodiment described later), for example, a second temperature difference (for example, a second temperature of the embodiment described later). The addition amount of the power distribution of the second drive device is determined according to a minimum temperature difference (for example, a minimum temperature difference ΔT_MIN in an embodiment described later) which is a smaller temperature difference of the temperature difference Δ2).

Moreover, in addition to the structure of Claim 2, the invention of Claim 3 is
The amount of addition of the power distribution of the second drive device increases as the minimum temperature difference decreases.

Moreover, in addition to the structure of any one of Claims 1-3, invention of Claim 4 is provided.
The control device changes the power distribution only for a predetermined time.

Moreover, in addition to the structure of any one of Claims 1-4, invention of Claim 5 is provided,
The control device has a predetermined power distribution rule below a predetermined vehicle speed (for example, a vehicle speed SP in an embodiment described later),
In the control device, a total power distribution amount of a power distribution amount of the second drive device and an addition amount of the power distribution of the second drive device determined by the power distribution rule exceeds a predetermined threshold power distribution amount. The power distribution is controlled so as not to occur.

  According to the first aspect of the present invention, the first drive source of the first drive device provided with the connection / disconnection means according to the heat generation of the connection / disconnection means or the rise of the liquid medium temperature accompanying the heat generation of the connection / disconnection means. By changing the power distribution between the first drive source and the second drive source so as to suppress the output and increase the output of the second drive source in the second drive device, the connection / disconnection means of the vehicle can be secured while securing the necessary power of the vehicle Temperature rise can be suppressed.

  According to the second aspect of the present invention, the first temperature difference that is the difference between the temperature of the connecting / disconnecting means and the predetermined first threshold temperature, and the difference between the temperature of the liquid medium and the predetermined second threshold temperature. By determining the addition amount of the power distribution of the second drive device according to the minimum temperature difference that is the smaller temperature difference of the second temperature differences, it is possible to more appropriately suppress the temperature rise of the connecting / disconnecting means.

  According to the third aspect of the invention, the load of the first drive device is reduced as the minimum temperature difference is increased by increasing the power distribution addition amount of the second drive device as the minimum temperature difference is smaller. The temperature rise of the connection / disconnection means can be suppressed more appropriately.

  According to the fourth aspect of the present invention, the power distribution can be determined based on the running performance and the like after a predetermined time while suppressing the temperature rise of the temporary connecting / disconnecting means.

  According to the fifth aspect of the present invention, the control device has a power distribution rule determined in advance at a predetermined vehicle speed or less, and the control device has a power distribution amount of the second drive device determined by the power distribution rule. By controlling the power distribution so that the total power distribution amount with the addition amount of the power distribution of the second drive device does not exceed the predetermined threshold power distribution amount, it is possible to suppress the load of the second drive device from becoming too high. .

1 is a schematic configuration diagram illustrating a schematic configuration of a vehicle according to an embodiment of the present invention. It is a block diagram of power distribution change control.

  Hereinafter, an embodiment of a vehicle according to the present invention will be described with reference to the drawings.

  The vehicle 10 of this embodiment includes a front wheel drive device 11 and a rear wheel drive device 12 that are mechanically independent. “Mechanically independent” means that one power is not mechanically transmitted to the other by a propeller shaft or the like.

  The front wheel drive device 11 includes a first drive source DS1 that generates power for driving the front wheels Wf, a transmission TM provided on a power transmission path between the first drive source DS1 and the front wheels Wf, and a first drive source DS1. And a clutch CL that is provided on a power transmission path with the front wheel Wf and that releases or fastens the power transmission between the first drive source DS1 and the front wheel Wf. The first drive source DS1 may be an engine, a motor, a hybrid system including an engine and a motor, or the like.

  The transmission TM may be a manual transmission (MT) or an automatic transmission (AT). Examples of the automatic transmission (AT) include CVT (Continuously Variable Transmission), DCT (Dual-clutch transmission), AMT (Automatic manual transmission), and torque converter step AT.

  The clutch CL may be a wet clutch or a dry clutch. In general, in the case of a wet clutch, the heat generated by the clutch is transmitted to the ATF, and the temperature of the ATF tends to rise. On the other hand, in the case of a dry clutch, the heat generated by the clutch tends to increase the temperature of the clutch as it is. However, depending on the input load conditions to the transmission TM and the environmental temperature, even if the clutch is a wet clutch, the temperature of the clutch becomes higher than the temperature of the ATF. May be higher.

  Therefore, the clutch CL is provided with a first temperature sensor TE1 that acquires the temperature of the clutch CL. Further, the transmission TM is provided with a second temperature sensor TE2 that acquires the temperature of an ATF (Automatic Transmission Fluid). Note that “acquisition” of the temperature in the first temperature sensor TE1 and the second temperature sensor TE2 is a concept including detection, calculation, estimation, and the like. For example, the temperature of the clutch CL is not directly detecting the temperature of the clutch CL. Alternatively, it may be estimated from the differential rotation of the clutch CL and the clutch torque.

  The rear wheel drive device 12 includes a second drive source DS2 that generates power for driving the rear wheel Wr, and a differential device DIF that distributes the power of the second drive source DS2 to the left and right rear wheels Wr. The second drive source DS2 may also be an engine, a motor, a hybrid system including an engine and a motor, or the like. Further, a transmission may be provided instead of the differential device DIF or together with the differential device DIF, and the second drive source DS2 and the axle of the rear wheel Wr may be directly connected.

  In FIG. 1, symbol CTR is a control device that controls the entire vehicle, and performs output control of the first drive source DS1 and second drive source DS2, release / engagement control of the clutch CL, and the like. The control device CTR receives the temperature of the ATF acquired by the first temperature sensor TE1 and the temperature of the clutch CL acquired by the second temperature sensor TE2.

  The control device CTR has a predetermined power distribution rule at a predetermined vehicle speed (for example, 30 km / h) or less for the purpose of suppressing vibration (judder) when the vehicle starts. This power distribution rule may be stored in a memory as a table or a map, or may be calculated each time according to the vehicle speed or the like.

FIG. 2 includes an example of a rear power distribution table showing the power distribution of the rear wheel drive device 12. This rear power distribution table shows the ratio of power to be output by the rear wheel drive device 12 with the required power of the vehicle being 100%.
The rear power distribution table shown in FIG. 2 shows that the power distribution amount of the rear wheel drive device 12 increases from a% to b% as the vehicle speed increases below a predetermined vehicle speed SP.

  The control device CTR basically controls power distribution between the front wheel drive device 11 and the rear wheel drive device 12 in accordance with the power distribution rule when the vehicle starts, but the viewpoint of protecting the clutch CL of the front wheel drive device 11 Therefore, power distribution change control for changing the power distribution of the rear wheel drive device 12 according to the heat generation of the clutch CL is performed.

<Power distribution change control>
Hereinafter, the power distribution change control will be described with reference to FIG.
In the power distribution change control, the control device CTR distributes the power of the rear wheel drive device 12 according to either the temperature of the clutch CL acquired by the first temperature sensor TE1 or the temperature of the ATF acquired by the second temperature sensor TE2. The power distribution is changed so that the amount increases. An increase in the power distribution amount of the rear wheel drive device 12 means a decrease in the power distribution amount of the front wheel drive device 11, and when the output of the first drive source DS1 of the front wheel drive device 11 decreases, the clutch CL is transmitted accordingly. Therefore, the heat generated by the clutch CL is suppressed.

  More specifically, the control device CTR includes a first temperature difference Δ1 that is a difference between the temperature of the clutch CL acquired by the first temperature sensor TE1 and a predetermined clutch allowable limit temperature, and a second temperature sensor TE2. The minimum temperature difference ΔT_MIN, which is the smaller temperature difference between the ATF temperature acquired in step 1 and the second temperature difference Δ2 that is the difference between the predetermined ATF allowable limit temperature, is obtained (minimum temperature difference selection process). Then, an addition amount of power distribution of the rear wheel drive device 12 is determined according to the minimum temperature difference ΔT_MIN.

  The clutch allowable limit temperature and the ATF allowable limit temperature are temperatures obtained by subtracting a margin (temperature margin) from the clutch limit temperature and the ATF limit temperature, respectively. The margin (temperature margin) is preferably defined by an absolute value (α ° C.) rather than a ratio (α%). Thereby, even when the clutch limit temperature and the ATF limit temperature are different, the margin can be set correctly.

  The power distribution addition amount of the rear wheel drive device 12 is determined based on the rear distribution addition table. In the rear distribution addition table, the smaller the minimum temperature difference ΔT_MIN, the larger. That is, when the first temperature difference Δ1 is smaller than the second temperature difference Δ2, the power distribution addition amount of the rear wheel drive device 12 is increased as the temperature of the clutch CL is closer to the clutch allowable limit temperature, and the second temperature difference Δ2 is increased. When the temperature difference is smaller than the first temperature difference Δ1, the power distribution addition amount of the rear wheel drive device 12 is increased as the ATF temperature is closer to the ATF allowable limit temperature.

  The control device CTR determines the power distribution amount of the rear wheel drive device 12 determined based on a power distribution rule (for example, a rear power distribution table) and the power of the rear wheel drive device 12 determined based on the rear distribution addition table. The total power distribution amount obtained by adding the distribution addition amount is obtained (total distribution amount acquisition processing).

  However, when the total power distribution amount exceeds a predetermined threshold power distribution amount, the control device CTR determines the power distribution of the rear wheel drive device 12 so that the total power distribution amount does not exceed the predetermined threshold power distribution amount ( Rear distribution limit processing). Thereby, it can suppress that the load of the rear-wheel drive device 12 becomes high too much.

  Furthermore, the control device CTR performs power distribution change control only for a predetermined time. That is, the control device CTR uses the power distribution amount of the rear wheel drive device 12 determined based on a power distribution rule (for example, a rear power distribution table) as the power distribution of the rear wheel drive device 12 after a predetermined time has elapsed. To do.

  As described above, according to the present embodiment, the control device CTR, depending on one of the temperature of the clutch CL acquired by the first temperature sensor TE1 and the temperature of the ATF acquired by the second temperature sensor TE2, The power distribution is changed so that the power distribution amount of the rear wheel drive device 12 increases. That is, the control device CTR suppresses the output of the first drive source DS1 in the front wheel drive device 11 provided with the clutch CL in accordance with the heat generation of the clutch CL or the ATF temperature rise accompanying the heat generation of the clutch CL, and the rear wheel drive. By changing the power distribution between the first drive source DS1 and the second drive source DS2 so as to increase the output of the second drive source DS2 in the device 12, the temperature of the clutch CL is increased while ensuring the necessary power of the vehicle 10. Can be suppressed.

  Further, the control device CTR obtains the first temperature difference Δ1 which is the difference between the temperature of the clutch CL acquired by the first temperature sensor TE1 and the predetermined allowable clutch temperature, and the ATF acquired by the second temperature sensor TE2. In accordance with the minimum temperature difference ΔT_MIN that is the smaller temperature difference of the second temperature difference Δ2 that is the difference between the temperature and the predetermined ATF allowable limit temperature, the power distribution addition amount of the rear wheel drive device 12 is increased. By determining, the temperature rise of the clutch CL can be suppressed more appropriately.

  Further, the amount of power distribution added to the rear wheel drive device 12 becomes larger as the minimum temperature difference ΔT_MIN is smaller. Therefore, the load on the front wheel drive device 11 is reduced as the clutch allowable limit temperature or ATF allowable limit temperature is closer. The temperature increase of the clutch CL can be appropriately suppressed.

  Further, the control device CTR changes the power distribution only for a predetermined time to suppress a temporary temperature increase of the clutch CL, while the control device CTR is based on the running performance after the predetermined time has elapsed. Power distribution can be determined.

  Further, the control device CTR has a predetermined power distribution rule below a predetermined vehicle speed SP, and the control device CTR determines the power distribution amount of the rear wheel drive device 12 and the rear wheel drive device 12 determined by the power distribution rule. By controlling the power distribution so that the total power distribution amount with the added power distribution amount does not exceed the predetermined threshold power distribution amount, it is possible to suppress the load of the rear wheel drive device 12 from becoming too high.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In the above embodiment, the front wheel drive device 11 is illustrated as the first drive device, and the rear wheel drive device 12 is illustrated as the second drive device. However, the first drive device is the rear wheel drive device 12 and the second drive device is the second drive device. The front wheel drive device 11 may be used.

10 Vehicle 11 Front Wheel Drive Device (First Drive Device)
12 Rear wheel drive device (second drive device)
CL clutch (connection / disconnection means)
CTR control device DS1 first drive source DS2 second drive source TE1 first temperature sensor TE2 second temperature sensor TM transmission Wf front wheel (first wheel)
Wr Rear wheel (second wheel)
Δ1 First temperature difference Δ2 Second temperature difference ΔT_MIN Minimum temperature difference

Claims (5)

A first drive source that generates power to drive the first wheel of either the front wheel or the rear wheel; a transmission provided on a power transmission path between the first drive source and the first wheel; A connecting / disconnecting means that is provided on a power transmission path between one drive source and the first wheel, and that releases or fastens the power transmission between the first drive source and the first wheel; A first drive device comprising:
A second drive device comprising a second drive source for generating power for driving the other second wheel of the front wheel and the rear wheel;
A control device that controls power distribution between the first drive device and the second drive device,
Connection / disconnection means temperature acquisition means for acquiring the temperature of the connection / disconnection means; and
Liquid medium temperature acquisition means for acquiring the temperature of the liquid medium that lubricates the transmission and the connection / disconnection means, and
The control device includes:
Acquiring the temperature of the connection / disconnection means by the connection / disconnection means temperature acquisition means, and acquiring the temperature of the liquid medium by the liquid medium temperature acquisition means,
The power distribution amount of the first drive unit is reduced in accordance with either the temperature of the connection / disconnection means acquired by the connection / disconnection means temperature acquisition means or the temperature of the liquid medium acquired by the liquid medium temperature acquisition means. is allowed to change the power distribution in so that increasing the power distribution of the second driving device, a vehicle. The vehicle according to claim 1,
The control device includes a first temperature difference that is a difference between the temperature of the connecting / disconnecting means and a predetermined first threshold temperature, and a second temperature difference that is a difference between the temperature of the liquid medium and a predetermined second threshold temperature. The amount of addition of the power distribution of the second drive device is determined according to a minimum temperature difference that is a smaller temperature difference of the two. The vehicle according to claim 2,
The vehicle, wherein the amount of addition of the power distribution of the second drive device increases as the minimum temperature difference decreases. The vehicle according to any one of claims 1 to 3,
The control device changes the power distribution only for a predetermined time. The vehicle according to any one of claims 1 to 4,
The control device has a predetermined power distribution rule below a predetermined vehicle speed,
In the control device, a total power distribution amount of a power distribution amount of the second drive device and an addition amount of the power distribution of the second drive device determined by the power distribution rule exceeds a predetermined threshold power distribution amount. The vehicle controls the power distribution so that there is no.

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