JP2011193700A - Motor vehicle front/rear-wheel drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor vehicle front/rear-wheel drive device that can miniaturize the motor of a second power unit for rear-wheel drive, compactify the second power unit, and achieve better mountability to a vehicle with the second power unit. <P>SOLUTION: The motor vehicle front/rear wheel drive device includes: a first power unit 3f that drives the front wheels 2f; and a second power unit 3r that drives the rear wheels 2r. The second power unit 3r comprises: a motor 10; and a deceleration device 11 that conveys the output of an output shaft 10a of the motor 10 to the rear wheels 2r. An output shaft 15a of an auxiliary motor 15 smaller than the motor 10 is connected with the rear wheels 2r via a clutch 17. A compressor of an air conditioner 20 is directly connected with the output shaft 10a of the auxiliary motor 15. The connection with the clutch 17 combines the outputs of the motor 10 and the auxiliary motor 15 to convey the combined output to the rear wheels 2r. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a first power unit that drives a front wheel and a second power unit that drives a rear wheel. The second power unit is a motor, and a speed reduction device that transmits the output of the output shaft of the motor to the rear wheel. It is related with the improvement of the front-and-rear wheel drive system of the car which consisted of

  Conventionally, in such front and rear wheel drive devices of such automobiles, a clutch is interposed in the transmission path between the motor and the rear wheels so that the compressor of the air conditioner can be driven regardless of the operating state of the first power unit. As disclosed in, for example, Patent Document 1, an air conditioner compressor driven by the output of a motor is connected to a transmission path between the clutch and the motor.

JP 2004-168176 A

  By the way, in the above-mentioned conventional one, the motor of the second power unit for driving the rear wheels is also forced to increase in size by bearing the driving of the compressor for the air conditioner. There is a tendency for the mountability of the two power units to the vehicle body to deteriorate.

  The present invention has been made in view of such circumstances, and enables the motor of the second power unit for driving the rear wheels to be miniaturized so that the second power unit can be made compact. An object of the present invention is to provide a front and rear wheel drive device for an automobile capable of improving mountability.

  In order to achieve the above object, the present invention includes a first power unit that drives a front wheel and a second power unit that drives a rear wheel. The second power unit includes a motor and an output of an output shaft of the motor. In a front and rear wheel drive system for an automobile configured with a reduction gear that transmits to a rear wheel, an output shaft of an auxiliary motor smaller than the motor is connected to the rear wheel via a clutch, and the output shaft of the auxiliary motor is connected to the rear wheel. The first feature is that the compressor of the air conditioner is directly connected, and the outputs of the motor and the auxiliary motor are summed and transmitted to the rear wheels by connecting the clutch. The motor corresponds to the second motor 10 in the embodiment of the present invention described later.

  According to the present invention, in addition to the first feature, the speed reducer is a speed reducer that decelerates the output rotation of the motor and transmits it to the load side, and a difference that distributes the output of the speed reducer to the left and right rear wheels. A second feature is that the auxiliary motor is connected to the output shaft of the motor via a clutch. The differential device corresponds to a second differential device 12 in an embodiment of the present invention described later.

  Further, in addition to the second feature, the present invention provides that the target torque of the rear wheel is set so that the target torque value of the second power unit is distributed to the second motor and the auxiliary motor at the highest overall efficiency. Judge whether it is in the S area where the efficiency is good or the M area where the efficiency of the second motor is good. In the S area, set the torque that maximizes the efficiency point of the auxiliary motor from the motor efficiency map and Complement the motor torque deficiency with the torque of the second motor, and in the M region, set the torque that maximizes the efficiency point of the second motor from the motor efficiency map. The third feature is that the torque is supplemented by the torque of the auxiliary motor.

  According to the first feature of the present invention, the output torque of the auxiliary motor that can drive the compressor of the air conditioner is summed with the output torque of the second motor by connecting the clutch, so that the driving force of the rear wheels can be effectively obtained. It is possible to enhance the driving ability against rough terrain. As a result, the second motor can be reduced in size, in particular, the diameter can be reduced by providing the auxiliary motor, contributing to the overall compactness of the second power unit and improving the mountability of the second power unit on the vehicle body. . Moreover, the air conditioner can be operated freely with the auxiliary motor alone by disengaging the clutch.

  According to the second feature of the present invention, the motor and the auxiliary motor share the reduction gear that transmits the respective output torque to the rear wheels, which can further contribute to the compactness of the second power unit.

  According to the third feature of the present invention, the second motor and the auxiliary motor are always operated in a state where the overall efficiency is high, and power consumption can be reduced.

1 is a schematic plan view of a front and rear wheel drive device for an automobile according to a first embodiment of the present invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. The electronic control block diagram of the said front-and-rear wheel drive device. The detailed electronic control block diagram which made the 2nd power unit system in the said front-and-rear wheel drive device a main body. The operation control table of the second power unit. Comprehensive operation control table for the front and rear wheel drive device The efficiency area | region diagram of the 2nd motor and auxiliary motor of a front-and-rear wheel drive device. Motor efficiency map (characteristic diagram of the driving torque of the second motor and the auxiliary motor and the total torque with respect to the vehicle speed). The flowchart for control of the said 2nd power unit. The flowchart following a part of control flowchart of FIG. FIG. 6 is a view corresponding to FIG. 1 showing a second embodiment of the present invention. FIG. 12 is a view taken in the direction of arrow 12 in FIG. 11. FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment of the present invention. FIG. 14 is a view taken in the direction of arrow 14 in FIG. 13.

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

  First, the description starts with the description of the first embodiment of the present invention shown in FIGS.

  1 and 2, the front and rear wheel drive device 1 of the automobile includes a first power unit 3f that drives a pair of left and right front wheels 2f and 2f, and a second power unit 3r that drives a pair of left and right rear wheels 2r and 2r. . The first power unit 3f includes an internal combustion engine 4, a first motor 5 connected to the output side of the internal combustion engine 4 and having a power generation and regenerative braking function, and the rotation of the first motor 5 is shifted to the load side. A belt type continuously variable transmission 6 for transmission and a first differential 7 for distributing the output of the transmission 6 to the left and right front wheels 2f, 2f.

  On the other hand, the second power unit 3r includes a second motor 10 having a power generation and regenerative braking function, a speed reducer 11 that decelerates and transmits the rotation of the output shaft 10a of the second motor 10 to the load side, and the speed reducer 11 The second differential device 12 distributes the output to the left and right rear wheels 2r, 2r. The reduction gear 11 reduces the rotation of the output gear 10a of the second motor 10 by one step and the rotation of the driven gear of the primary reduction gear row 11a by another step to reduce the rotation of the output shaft 10a by one step. The differential case 12a of the second differential device 12 is integrally connected to one side of the driven gear of the secondary reduction gear train 11b. The secondary reduction gear train 11b is disposed between the second motor 10 and the primary reduction gear train 11a.

  The second power unit 3r can further drive the rear wheels 2r and 2r through the speed reducer 11 and the second differential device 12 together with the second motor 10, and can be driven by the auxiliary motor 15 that is smaller than the second motor 10. Is provided. The output shaft 15a of the auxiliary motor 15 is connected to the output shaft 10a of the second motor 10 through the coaxially arranged intermediate shaft 16, the clutch 17 and the auxiliary reduction gear train 18. When the clutch 17 is connected, the auxiliary motor 15 The rotation of the output shaft 15 a can be decelerated one step and transmitted to the output shaft 10 a of the second motor 10. A compressor of an air conditioner (hereinafter simply referred to as an air conditioner) 20 is directly connected to the output shaft 15 a of the auxiliary motor 15. The auxiliary reduction gear train 18 is disposed between the second motor 10 and the primary reduction gear train 11a.

Thus, the four wheels of the front wheels 2f and 2f and the rear wheels 2r and 2r can be simultaneously driven by the simultaneous operation of the first and second power units 3f and 3r. At that time, the operation of the second power unit 3r has the following three modes.
(1) A mode in which the clutch 17 is disengaged and the rear wheels 2r and 2r are driven only by the output of the second motor 10.
(2) A mode in which the compressor of the air conditioner 20 is independently driven by the operation of the auxiliary motor 15 while the clutch 17 is disengaged and the rear wheels 2r and 2r are driven only by the output of the second motor 10.
(3) A mode in which the clutch 17 is connected and the rear wheels 2r and 2r are driven by the combined output of the second motor 10 and the auxiliary motor 15 and the compressor of the air conditioner 20 is driven.

  According to the above aspect (3), the output of the auxiliary motor 15 that can drive the compressor of the air conditioner 20 is added to the output of the second motor 10 to effectively enhance the driving force of the rear wheels 2r and 2r. It is possible to improve the running ability against rough terrain. Therefore, since the auxiliary motor 15 is provided, the second motor 10 can be reduced in size, in particular, reduced in diameter, contributing to the overall compactness of the second power unit 3r, and improving the mountability of the second power unit 3r on the vehicle body. Bring.

  Further, the second motor 10 and the auxiliary motor 15 are connected to the rear wheel via the speed reducer 11 and the auxiliary motor 15 is connected to the output shaft 10a of the second motor 10 via the clutch 17. Therefore, the reduction gear 11 that transmits the output torques to the rear wheels 2r and 2r is shared, which can contribute to the compactness of the second power unit 3r.

  In FIG. 3, the MG-ECU 22 determines the driving pattern after setting the target torque and the target control amount (temperature, air volume, etc.) of the air conditioner 20 based on various driving information 23 of the vehicle input thereto. Next, determination control based on the motor efficiency map (FIG. 8), switching of the clutch 17 and operation determination of the air conditioner 20 are performed in an integrated manner. Based on the result, the first motor ECU 24 controls the driving and regeneration of the first motor 5 via the first PDU 25, and the second motor ECU 26 controls the driving and regeneration of the second motor 10 via the second PDU 27. The auxiliary motor ECU 28 controls the driving of the auxiliary motor 15 via the third PDU 29, and the speed change ECU 38 controls the speed change of the transmission 6. Further, the MG-ECU 22 controls connection and disconnection of the clutch 17 based on the determination result. Further, the air conditioner ECU 30 controls the operation of the compressor of the air conditioner 20 by a command signal from the MG-ECU 22, and the engine ECU 31 controls the fuel injection amount in the internal combustion engine 4 of the first power unit 3f by a command signal from the MG-ECU 22. The battery ECU 32 controls charging / discharging of a battery (not shown) according to a command signal from the MG-ECU 22.

  The control of the first motor 5, the second motor 10 and the auxiliary motor 15 by the MG-ECU 22 will be described in more detail with reference to FIG. The MG-ECU 22 recognizes the driver's acceleration / deceleration request from the accelerator pedal opening, the on / off state of the brake switch, etc., and recognizes the driving information 23 such as the vehicle speed, engine speed, vehicle acceleration / deceleration, etc. Based on the recognition, the required total torque of the vehicle, the torque distribution ratio to the front wheels 2f and 2f and the rear wheels 2r and 2r, and the shift position of the transmission 6 are calculated, and the control values of each part of the first power unit 3f are calculated. (Fuel injection amount of the internal combustion engine 4, ignition timing, target torque value of the first motor 5, shift position of the transmission 6, etc.) and target control values (second motor 10 and auxiliary motor 15) of each part of the second power unit 3r The target torque value etc.) is calculated. In addition, the driver's request for the air conditioner 20 is recognized from the on / off state of the air conditioner switch and the air conditioner set temperature, and the target control value (temperature, air volume, humidity, etc.) of the air conditioner 20 is calculated. Then, based on the calculated target control value of each part of the second power unit 3r and the target control value of the air conditioner 20, the operation determination of the second power unit 3r is performed, and the second motor ECU 26, the auxiliary motor ECU 28, and the air conditioner A command signal is output to the ECU 30.

  The operation determination of the second power unit 3r performed by the MG-ECU 22 has seven patterns as shown in FIG. Here, in the patterns 4 and 7, determination control based on the motor efficiency map (FIG. 8) is necessary, which will be described below.

  It is important to distribute the target torque value of the second power unit 3r to the second motor 10 and the auxiliary motor 15 at a rate with the highest total motor efficiency, and a method for calculating the distribution will be described.

  First, the axle torque Trr applied to the rear wheels 2r and 2r from the second motor 10 and the axle torque Tsub applied to the rear wheels 2r and 2r from the auxiliary motor 15 are obtained.

Trr = Trrmot × ηrrmot × irr × ηgbox
Tsub = Tsubmot × ηsubmot × isub × ηsubg × irr × ηgbox
However, Trrmot ... Output torque of the second motor 10
Tsubmot: Output torque of auxiliary motor 15 ηrrmot: Efficiency of second motor 10 ηsubmot: Efficiency of auxiliary motor 15
irr ... Reduction ratio of reduction gear 11
isub: Reduction ratio of auxiliary reduction gear train 18 ηgbox: Transmission efficiency of reduction gear 11 ηsubg: Transmission efficiency of auxiliary reduction gear train 18 [Relationship between target torque and parameters]
The relationship between the target torque (Trt) of the rear wheels 2r and 2r and the output torque, current, and efficiency of the second motor 10 and the auxiliary motor 15 is organized as follows.

Trt = Trr + Tsub
Trr = Trrmot × irr × ηgbox
Tsub ＝ Tsubmot × isub × ηsubg × irr × ηgbox
Trrmot = E × Irr × ηrrmot
Tsubmot = E × Isubmot × ηsubmot
E ... Supply voltage to the second motor 10 and the auxiliary motor 15
Irr ・ ・ ・ ・ Supply current to the second motor 10
Isubmot ・ ・ Supply current to auxiliary motor 15 [torque setting of second motor 10]
Basically, it is determined from the torque efficiency on the output shaft 10a of the second motor 10.

Transform the above equation,
Trt = A × (Irr × ηrrmot + Isubmot × ηsubmot × B)
In the above formula, A = E x irr x ηgbox
B = isub × ηsubg
Here, the sum (Irrmot + Isubmot) of the current value on the second motor 10 side and the current value on the auxiliary motor 15 side is minimized.
[Torque setting from motor efficiency map (FIG. 8) (determined by efficiency on output shaft 10a of second motor 10)]
It is determined from the product of the efficiency of the second motor 10 and the auxiliary motor 15, the reduction ratio of the auxiliary reduction gear train 18 and the transmission efficiency.

S region in Fig. 7 ... ηsubmot ≥ 1 / B × ηrrmot
The S region is when the efficiency of the auxiliary motor 15 is good (see, for example, point P in FIG. 7), and the torque at which the efficiency point of the auxiliary motor 15 is maximized is set from the motor efficiency map (FIG. 8). The shortage of 15 torque is compensated by the torque of the second motor 10.

M region in FIG. 7... Ηsubmot <1 / B × ηrrmot
The M region is the case where the efficiency of the second motor 10 is good. From the motor efficiency map (FIG. 8), the torque at which the efficiency point of the second motor 10 is maximized is set, and the shortage of the torque of the second motor 10 is determined. It supplements with the torque of the auxiliary motor 15.

  In FIG. 7, the fact that the area of the S region is larger than that of the M region means that the frequency of setting the torque of the auxiliary motor 15 to the maximum is high.

  FIG. 8 is a motor efficiency map showing the characteristics of the driving torque of each motor with respect to the vehicle speed. In the figure, the line M is the characteristic of the second motor 10, the line S is the characteristic of the auxiliary motor 15, and the line MS is the both motors 10,15. The combined characteristics of are shown. In the figure, an example of the operating point during normal driving will be described. For example, the required torque of the rear wheels 2r and 2r is the maximum of the auxiliary motor 15 at that time, as in driving at the low vehicle speed V shown in FIG. When the torque is larger than the torque and smaller than the maximum torque of the second motor 10, both the motors 10 and 15 are operated so that the shortage of the auxiliary motor 15 is compensated by the torque of the second motor 10. The overall motor efficiency can be best maintained.

  It should be noted that the overall operation control of the front and rear wheel drive device of the automobile can be understood from FIG.

  The control procedure so far will be described with reference to the control flowcharts shown in FIGS.

  In FIG. 9, it is determined whether or not there is a request for operating the air conditioner 20 in the first step S1, and if YES, the process proceeds to the second step S2 to determine whether or not there is a torque request for the rear wheels 2r and 2r. The target value of the torque of the air conditioner 20 is set in advance, and then the process proceeds to the fourth step S4, the auxiliary motor 15 is operated to drive the compressor of the air conditioner 20, and the clutch 17 is brought into the connected state in the fifth step S5. .

  If YES is determined in the second step S2, the process proceeds to a sixth step S6 to set a target value of the sum of the torque of the rear wheels 2r and 2r and the torque of the air conditioner 20, and then to the seventh step S7. It is determined whether or not the vehicle travels forward, and if YES, the process proceeds to the twelfth step S12 in FIG. 10, and the torque distribution ratio between the second motor 10 and the auxiliary motor 15 corresponding to the vehicle speed is determined from the motor efficiency map (FIG. 8). Then, the process proceeds to the thirteenth step S13 to determine ηsubmot ≧ 1 / B × ηrrmot. If YES, that is, if the S region (FIG. 7) is determined, the maximum torque is applied to the auxiliary motor 15 in the fourteenth step S14. Then, in the fifteenth step S15, the clutch 17 is engaged, and in a sixteenth step S16, the torque shortage of the auxiliary motor 15 (target torque value−maximum torque of the auxiliary motor 15) Only the second motor 10 generates torque.

  When it is determined NO in the thirteenth step S13, that is, when it is determined that the M region (FIG. 7), the process proceeds to a seventeenth step S17 to determine whether or not the target torque value is larger than the torque of the second motor 10. When YES, that is, when the torque of the second motor 10 is insufficient, the process proceeds to 18th step S18 to operate the auxiliary motor 15 so as to compensate for the shortage of torque of the second motor 10, and in 19th step S19, the clutch 17 is engaged. Connected.

  When NO is determined in the 17th step S17, that is, when it is determined that the torque of the second motor 10 is sufficient, the process proceeds to a 20th step S20, and only the second motor 10 is set in an operating state.

  Returning to FIG. 9, when it is determined as NO in the seventh step S7, that is, when it is determined that the vehicle is moving backward, the process proceeds to an eighth step S8 where the clutch 17 is disengaged and the auxiliary motor 15 is operated. While driving the air conditioner 20, the second motor 10 is operated in the reverse direction. That is, the auxiliary motor 15 is involved only in the operation of the air conditioner 20 during reverse travel.

  When it is determined NO in the first step S1, the process proceeds to a tenth step S10 to determine whether or not there is a torque request for the rear wheels 2r, 2r. When YES, the process proceeds to an eleventh step S11 and the target value of the rear wheel torque is determined. Then, the process proceeds to the twelfth step S12 of FIG. 10, and thereafter, as described above.

  As described above, when the target torque value of the second power unit 3r is distributed to the second motor 10 and the auxiliary motor 15 at the ratio of the highest overall efficiency, the target torque of the rear wheels 2r and 2r depends on the efficiency of the auxiliary motor 15. Is determined to be in the S region or the efficiency of the second motor 10 is determined to be in the M region. In the S region, the torque at which the efficiency point of the auxiliary motor 15 is maximized is calculated from the motor efficiency map (FIG. 8). The torque deficiency of the auxiliary motor 15 is compensated with the torque of the second motor 10, and in the M region, the torque at which the efficiency point of the second motor 10 is maximized is set from the motor efficiency map (FIG. 8). Thus, since the shortage of the torque of the second motor 10 is compensated by the torque of the auxiliary motor 15, the second motor 10 and the auxiliary motor 15 are always operated with a high overall efficiency. Ri, it is possible to achieve savings in power consumption.

  Next, a second embodiment of the present invention shown in FIGS. 11 and 12 will be described.

  In the second embodiment, an auxiliary output gear 35 having a diameter smaller than that of the drive gear of the primary reduction gear train 11a is attached to the intermediate shaft 16, and this is engaged with the drive gear of the primary reduction gear train 11a. Except for the point that the motor 15 is arranged in the axial projection plane of the second motor 10, the configuration is the same as that of the previous embodiment, and in FIG. 11 and FIG. A referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

  According to the second embodiment, the auxiliary motor 15 can be arranged in the axial projection plane of the second motor 10, and in particular, the front-rear dimension L1 (see FIG. 12) of the second power unit 3r can be shortened. It becomes possible.

  Finally, a third embodiment of the present invention shown in FIGS. 13 and 14 will be described.

  In the third embodiment, an auxiliary motor 15 is arranged adjacent to and parallel to the periphery of the second motor 10, and an auxiliary output gear 35 having a diameter smaller than that of the drive gear of the primary reduction gear train 11a is attached to the intermediate shaft 16. Except for the point that this is engaged with the drive gear of the primary reduction gear train 11a via the idle gear 36, the configuration is the same as that of the first embodiment and the previous embodiment. Parts corresponding to those in the embodiment are denoted by the same reference numerals, and redundant description is omitted.

  According to the third embodiment, the axial dimension L2 (see FIG. 13) of the second power unit 3r can be particularly shortened by the adjacent arrangement of the auxiliary motor 15 around the second motor 10.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the auxiliary motor 15 can be connected to the speed reducer 11. The clutch 17 can be used regardless of its type, such as an electromagnetic clutch or a hydraulic clutch. In addition, a one-way clutch is provided in the drive system of the auxiliary motor 15 for the air conditioner 20 so that when the vehicle reverses, the auxiliary motor 15 is operated backward without being interfered by the air conditioner 20 and the torque is transferred to the reverse of the second motor 10. It is also possible to add to the torque.

1... Front and rear wheel drive device 2 f... Front wheel 2 r... Rear wheel 3 f... First power unit 3 r.・ ・ ・ ・ ・ ・ Motor (second motor)
10a... Output shaft 11 of the motor... Reduction gear 15... Auxiliary motor 15a. ... Air conditioner

Claims (3)

A first power unit (3f) for driving the front wheel (2f) and a second power unit (3r) for driving the rear wheel (2r) are provided. The second power unit (3r) is connected to the motor (10) and the motor. In the front-and-rear wheel drive device for an automobile configured with the reduction gear (11) that transmits the output of the output shaft (10a) of (10) to the rear wheel (2r),
An output shaft (15a) of an auxiliary motor (15) smaller than the motor (10) is connected to the rear wheel (2r) via a clutch (17), and the output shaft (10a) of the auxiliary motor (15). The compressor of the air conditioner (20) is directly coupled to the clutch (17), and the outputs of the motor (10) and the auxiliary motor (15) are added together and transmitted to the rear wheel (2r). A front and rear wheel drive device for an automobile characterized by the above. The front and rear wheel drive device for an automobile according to claim 1,
The speed reducer (11) decelerates the output rotation of the motor (10) and transmits it to the load side, and the output of the speed reducer (11) is distributed to the left and right rear wheels (2r). A front and rear wheel of an automobile, wherein the auxiliary motor (15) is connected to an output shaft (10a) of the motor (10) via a clutch (17). Drive device. The front and rear wheel drive device for an automobile according to claim 2,
In order to distribute the target torque value of the second power unit (3r) to the second motor (10) and the auxiliary motor (15) with the highest overall efficiency, the target torque of the rear wheel (2r) is set to the auxiliary motor (15 ) Is in the S region where the efficiency is good, or the second motor (10) is in the M region where the efficiency is good. In the S region, the efficiency point of the auxiliary motor (15) is maximized from the motor efficiency map. The torque of the auxiliary motor (15) is compensated for by the torque of the second motor (10). In the M region, the efficiency point of the second motor (10) is maximized from the motor efficiency map. The front and rear wheel drive device for an automobile is characterized in that the torque deficiency of the second motor (10) is compensated by the torque of the auxiliary motor (15).

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