JP2009207243A - Braking force regeneration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a braking force regeneration device with which sufficient regeneration can be obtained even when wheels are rotating at low speed. <P>SOLUTION: The braking force regeneration device is comprised of: a power source 11 for generating rotary torque; a clutch means 13 that is connected to the power source 11 and controls the transmission of rotary torque; a speed change means 15 connected to the clutch means 13; wheels 17 connected to the speed change means 15; a number-of-revolutions selecting means 19 that is connected to the clutch means 13 and takes rotary torque out of whichever is higher, the power source-side number of revolutions of the clutch means 13 or the speed change means-side number of revolutions of the clutch means 13; and a generator 21 that is connected to the number-of-revolutions selecting means 19 and to which the rotary torque taken out by the number-of-revolutions selecting means 19 is transmitted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a braking force regeneration device that recovers kinetic energy by driving an auxiliary machine during deceleration of a vehicle.

  In recent years, various devices that utilize the kinetic energy of a vehicle being decelerated have been proposed in order to consider the environment and improve fuel efficiency. For example, in Patent Document 1, the driving torque of an engine such as an air conditioner compressor and a generator (alternator) is driven by utilizing the rotational torque of wheels caused by the inertial force when the vehicle is decelerated. Auxiliary drive devices that can suppress the required fuel consumption have been proposed. FIG. 5 is an overall configuration diagram of such an accessory driving device.

  In FIG. 5, the vehicle engine 101 rotates an axle 107 via a speed reduction mechanism 103 and a differential 105. As a result, the wheels 109 fixed to the axle 107 rotate to drive the vehicle. On the other hand, a crankshaft pulley 113 is connected to the engine 101 via a crankshaft 111. An auxiliary machine 117 such as an alternator and a compressor and an electric starter 119 of the engine 101 are connected to the crankshaft pulley 113 via a belt 115. Therefore, when the engine 101 is started, the belt 115 and the crankshaft pulley 113 are rotated by driving the electric starter 119 with electric power from a battery (not shown), thereby enabling the engine 101 to be started. . Further, since the auxiliary machine 117 is driven via the crankshaft pulley 113 and the belt 115 while the engine 101 is being driven, power generation, air conditioner driving, and the like are possible.

Next, the operation at the time of deceleration will be described. An axle pulley 121 is provided on the axle 107, and a belt 123 is disposed between the axle 107 and the crankshaft pulley 113. The crankshaft pulley 113 and the axle pulley 121 have a built-in clutch mechanism. Thus, during deceleration, the crankshaft pulley 113 is turned off (separated) and the axle pulley 121 is turned on (engaged), so that the rotational torque of the axle 107 due to the kinetic energy of the vehicle passes through the belts 123 and 115 and the auxiliary machine 117. Is transmitted to. Therefore, the auxiliary machine 117 can be driven by the kinetic energy during vehicle deceleration. At this time, since the rotational torque of the engine 101 is not transmitted to the auxiliary machine 117, the engine 101 can be stopped. Thus, since the energy for driving the auxiliary machine 117 during deceleration is obtained from the kinetic energy due to the deceleration of the vehicle, the auxiliary machine 117 can be driven without using fuel, and the engine 101 is stopped during deceleration. The fuel consumption of the entire vehicle is improved.
JP 2002-174305 A

  According to the above auxiliary machine drive device, even if the engine 101 is stopped at the time of deceleration, the auxiliary machine 117 can be driven by the rotational torque of the wheel 109 based on the kinetic energy of the vehicle, and the fuel efficiency can be improved. When rotating at low speed, there were the following problems.

  For example, when the auxiliary machine drive device of FIG. 5 is applied as a power regeneration device, the configuration is simply configured by connecting power storage means for storing electric power obtained by braking to the auxiliary machine 117 formed of a generator. . In this case, when the wheel 109 is rotating at a high speed, the auxiliary machine 117 is also rotated at a high speed, and a sufficient amount of power generated by regeneration during deceleration (hereinafter referred to as regenerative power) can be obtained. Repeatedly, when the wheel 109 rotates only at a low speed, the rotational speed of the auxiliary machine 117 remains low, and there is a problem that sufficient regenerative power cannot be obtained. Similarly, when the auxiliary machine 117 is a compressor or a hydraulic pump, there is a problem that a sufficient pressure due to energy regeneration cannot be obtained when the wheel 109 rotates at a low speed.

  An object of the present invention is to solve the above-described conventional problems, and to provide a braking force regeneration device capable of obtaining sufficient regeneration even when the wheel 109 rotates at a low speed.

  In order to solve the above-described conventional problems, a braking force regeneration device according to the present invention includes a power source that generates rotational torque, a clutch unit that is connected to the power source and controls transmission of the rotational torque, and the clutch unit. The speed change means connected to the speed change means, the wheel connected to the speed change means, the clutch means connected to the power source side rotational speed of the clutch means, and the speed change means side speed of the clutch means from the higher one A rotation speed selection means for extracting the rotation torque and an auxiliary machine connected to the rotation speed selection means and to which the rotation torque extracted by the rotation speed selection means is transmitted.

  According to the braking force regeneration device of the present invention, since the rotational torque of the wheel is transmitted to the auxiliary machine through the speed change means and the speed selection means, when the wheel is rotating at a low speed due to a traffic jam or the like, the speed change means A higher rotational speed than the rotational speed of the wheel is obtained. Further, if the rotational torque of the wheels is larger than the rotational torque of the power source during deceleration and the clutch means is turned off, the speed change means side rotational speed becomes higher than the power source side rotational speed. Therefore, in these cases, the rotational speed selection means transmits the higher one of the power source side rotational speed and the transmission means side rotational speed to the auxiliary equipment, so that the rotational torque of the wheels is transmitted to the auxiliary equipment. . Therefore, even if the wheel rotates at a low speed, a higher rotational speed than that of the wheel is transmitted to the auxiliary machine, so that sufficient regeneration can be obtained, and an effect that a braking force regeneration device that contributes to further improvement in fuel efficiency can be realized can be obtained. . When the vehicle is stopped, the clutch means is turned off and the power source is in an idling state. However, since the power source side rotational speed is larger than the transmission means side rotational speed (= 0), the power is selected by the rotational speed selection means. The rotational torque of the source is transmitted to the auxiliary machine. This operation is the same as that of a general vehicle. Therefore, it is possible to realize a braking force regeneration device that can perform a general vehicle operation and obtain sufficient regeneration.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a braking force regeneration device according to Embodiment 1 of the present invention. FIG. 2 is a time-dependent change diagram of various characteristics of the braking force regeneration device according to the first embodiment of the present invention. FIG. (C) is a time-dependent change diagram of the power generation amount, (d) is a time-change graph of the DC / DC converter input power, and (e) is a time-change graph of the power storage means power storage amount. In FIG. 1, thick double lines indicate various rotation axes. In the first embodiment, a case where a generator is used as an auxiliary machine will be described.

  In FIG. 1, a power source 11 that is an engine of a vehicle is connected to one end of a clutch means 13 via a rotating shaft. A speed change means 15 is connected to the other end of the clutch means 13 via a rotating shaft. Therefore, the clutch means 13 has a function of engaging and separating the rotary shaft between the power source 11 and the speed change means 15. Thereby, transmission of the rotational torque generated by the power source 11 is controlled by the clutch means 13. For example, a torque converter may be used as the clutch means 13. Further, the transmission means 15 is equipped with an automatic transmission mechanism that shifts hydraulically.

  A wheel 17 is connected to the output side of the transmission means 15 via a rotating shaft. A differential is interposed between the speed change means 15 and the wheel 17, but is omitted in FIG.

  A rotation speed selection means 19 is connected to the clutch means 13. Specifically, as shown in FIG. 1, a rotation speed selection means 19 is connected between the power source 11 and the clutch means 13 and between the clutch means 13 and the transmission means 15. Further, a generator 21 is connected as an auxiliary machine to the output of the rotational torque extracted by the rotational speed selection means 19.

  Here, the detailed configuration of the rotation speed selection means 19 will be described. The rotational speed selection means 19 is a portion surrounded by a thin dotted line in FIG. 1. First, a power source side pulley 23 for extracting the rotational torque of the power source 11 is provided between the power source 11 and the clutch means 13. . The power source side pulley 23 is directly connected to the rotating shaft from the power source 11. Similarly, between the clutch means 13 and the speed change means 15, a speed change means side pulley 25 for taking out the rotational torque of the speed change means 15 is provided. The transmission means side pulley 25 is also directly connected to the rotating shaft from the transmission means 15. The power source side pulley 23 and the transmission means side pulley 25 are each connected to a generator side pulley 29 via a belt 27. Two generator-side pulleys 29 are provided, both of which are attached to a rotating shaft connected to the generator 21 as shown in FIG. Further, the generator-side pulley 29 has a built-in one-way clutch mechanism, and the power source side rotational speed between the power source 11 and the clutch means 13 and the speed change means side between the clutch means 13 and the speed change means 15. The rotational torque is extracted from the higher one of the rotational speeds and transmitted to the generator 21.

  In FIG. 1, the clutch means 13 and the speed change means 15 are shown separately. In the first embodiment, the clutch means 13 is a torque converter with a lockup mechanism, and is integrated with the speed change means 15 having an automatic speed change mechanism. It was supposed to have. Therefore, the speed change means side pulley 25 is built in a portion between the clutch means 13 and the speed change means 15, and the belt 27 takes out the rotation torque on the speed change means side. Further, the belt 27 is not limited to this, and a configuration may be adopted in which the rotational torque on the transmission means side is extracted by a gear or a rotating shaft. Further, since the lock-up mechanism can be turned on and off from the outside, the engagement and separation of the clutch means 13 can be controlled externally.

  Next, a detailed configuration of electrical connection will be described. A battery 31 and an electric load 33 are connected to the generator 21 in the same manner as a general vehicle. The electric load 33 in the first embodiment is an electrical component mounted on the vehicle, and does not include an air conditioner compressor driven by the power source 11 or various hydraulic pumps. In addition to the above configuration, in the first embodiment, the output of the generator 21 is connected to the power storage means 37 via the DC / DC converter 35. Here, the electricity storage means 37 is a large-capacity electric double layer capacitor capable of rapid charging / discharging. This makes it possible to sufficiently store the steep regenerative power generated when the vehicle is decelerated. The amount of electricity stored in the electricity storage means 37 is defined as 0% for the lower limit voltage and 100% for the upper limit voltage in the voltage range during operation of the electric double layer capacitor.

  On the other hand, a control unit 39 is connected to the power source 11, the clutch unit 13, the transmission unit 15, the generator 21, and the DC / DC converter 35. The control means 39 is composed of a microcomputer and peripheral components. Besides the above-described ones, rotation sensors provided in the vicinity of the power source side pulley 23 and the transmission means side pulley 25 are connected, although not shown. Each speed is detected. In addition, it controls the entire vehicle.

  Next, the operation of such a braking force regeneration device will be described with reference to FIG. In FIG. 2, the horizontal axis of all graphs indicates time. FIG. 2 shows an example of a situation where the vehicle repeats acceleration / deceleration in a traffic jam but the vehicle speed does not increase much. Therefore, during the operation period of FIG. 2, the automatic transmission of the speed change means 15 remains in the low (first speed) gear, or is in the state up to the second (second speed) gear even if shifted up.

  First, it is assumed that the vehicle has stopped at time t0. Therefore, the vehicle speed is zero as shown in FIG. Further, since the power source 11 is in the idling state, the idling rotational speed ri is maintained. Accordingly, as shown in FIG. 2B, the rotational speed on the power source side (indicated by the thick solid line in FIG. 2B) becomes the idling rotational speed ri at time t0. At this time, since the vehicle is stopped by the brake, the rotation speed of the wheel 17 is zero. Therefore, since the speed change means 15 connected to the wheel 17 is not rotating, the speed on the speed change means side (indicated by a thick dotted line in FIG. 2B) becomes 0 at time t0. For these reasons, since the rotational speeds of the power source side and the transmission means side of the clutch means 13 are different, the control means 39 turns off the lock-up mechanism of the clutch means 13 when the vehicle is stopped. Thereby, the clutch means 13 has isolate | separated the power source side and the transmission means side. In the first embodiment, the lock-up mechanism of the clutch means 13 is on / off controlled by the control means 39. This is a structure incorporating a mechanism that is mechanically turned off when a predetermined vehicle speed is reached during deceleration. Also good.

  As shown in FIG. 2B, since the rotational speed of the clutch means 13 is higher on the power source side than on the transmission means side, the rotational speed selection means 19 mechanically applies the rotational torque on the higher speed side, that is, the power source side. This is transmitted to the generator 21. Thereby, as shown in FIG. 2C, the generator 21 is driven by idling rotation of the power source 11 to generate a certain amount of power. This electric power is supplied to the electric load 33 and charged depending on the state of charge of the battery 31. In the following description, the power consumption of the electric load 33 is assumed to be constant after the time t0 in FIG.

  Here, at time t0, the regenerative power cannot be obtained because the vehicle is stopped. Therefore, the control means 39 stops the DC / DC converter 35. Therefore, as shown in FIG. 2D, the input power of the DC / DC converter 35 becomes 0, and the power storage means 37 is not charged. Therefore, as shown in FIG. 2E, the power storage means 37 maintains a state where the power storage amount is 0%.

  Next, it is assumed that the brake is released at time t1 and the vehicle starts to accelerate when the accelerator pedal is depressed. Thereby, as shown to Fig.2 (a), a vehicle speed becomes large with time. As a result, as indicated by the thick solid line in FIG. 2B, the rotational speed on the power source side increases with time, and the rotational speed (thick dotted line) on the transmission means side is also increased by the torque converter of the clutch means 13 accordingly. It rises over time. At this time, since the power source 11 is at idling rotational speed at time t1 and the speed change means 15 is not rotating, the rotational speed on the power source side is higher, but eventually both rotational speeds coincide at time t2. Furthermore, the number of revolutions continues to rise. Since the rotational speed on the power source side is higher from time t1 to time t2, the generator 21 is driven by the rotational torque of the power source pulley 23. At this time, since the power consumption of the electric load 33 is constant as described above, the power generation amount of the generator 21 is constant as shown in FIG. In addition, during the period from time t1 to time t2, regenerative power is not generated because acceleration is being performed. Therefore, the DC / DC converter 35 remains stopped, and the input power thereof is maintained at 0 as shown in FIG. Therefore, since the power storage means 37 is not charged, the power storage amount remains 0%.

  Next, from the time t2 to the time t3, the vehicle is accelerating, but the rotational speeds on the power source side and the transmission means side coincide with each other. In this case, in order to reduce the loss due to the torque converter of the clutch means 13, the control means 39 turns on the lockup mechanism. As a result, the power source side and the transmission means side are engaged by the clutch means 13, so that fuel efficiency can be improved. Further, as described above, since the rotational speeds on the power source side and the transmission means side are equal from time t2 to time t3, the generator 21 is driven by the rotational torque on both the power source side and the transmission means side, but the time t1 From time t2, the power generation amount of the generator 21 does not change. Therefore, the input power of the DC / DC converter 35 is 0, and the amount of electricity stored in the electricity storage means 37 remains 0%.

  Next, it is assumed that acceleration ends at time t3 and the wheel 17 starts to decelerate. As a result, the rotational torque output from the power source 11 becomes substantially zero, and the clutch means 13 rotates through the speed change means 15 by the rotational torque from the wheels 17 obtained from the kinetic energy of the vehicle. At this time, since the clutch means 13 is engaged by the lock-up mechanism, the power source side pulley 23 and the transmission means side pulley 25 rotate at the same rotational speed. Therefore, since the generator 21 is driven by the rotational torque of both pulleys, the electric power obtained is based on the kinetic energy of the vehicle. Therefore, it becomes possible to collect the kinetic energy generated by vehicle braking as regenerative power.

  In the first embodiment, an example of regenerating kinetic energy by braking more efficiently by increasing the power generation output of the generator 21 during deceleration will be described below.

  When the wheel 17 decelerates, as shown in FIGS. 2 (a) and 2 (b), the vehicle speed and the number of rotations of the clutch means respectively decrease with time. At this time, the control means 39 controls the generator 21 to increase the power generation amount in order to recover the regenerative power due to the deceleration of the wheels 17. That is, the control means 39 controls the DC / DC converter 35 to temporarily generate the generator 21 with a high output and charge the generated regenerative power to the power storage means 37. As a result, as shown in FIG. 2C, the power generation amount of the generator 21 increases by the amount of regenerative power at time t3. Therefore, the generator 21 generates the sum of the electric power supplied to the electric load 33 supplied up to time t3 and the regenerative electric power supplied to the power storage means 37. Due to the generation of the regenerative power, as shown in FIG. 2D, the input power of the DC / DC converter 35 suddenly increases at time t3 and becomes a constant value. This is because the input power of the DC / DC converter 35 is controlled to be constant. By this operation, charging of the power storage means 37 is started, and the amount of power storage increases with time from time t3 as shown in FIG.

  Note that at the start of deceleration at time t3, the fuel supply to the power source 11 is interrupted in the same manner as in the past in order to improve fuel efficiency.

  Next, after time t3, as shown in FIG. 2 (b), the rotational speed of the clutch means 13 also decreases as the vehicle speed decreases, but the clutch means 13 is engaged until time t4. The power source 11 is rotated by the wheel 17 without consuming fuel. Therefore, the power source side rotational speed and the speed change means side rotational speed are in the same state.

  At time t4, the power source side rotational speed reaches the lower limit rotational speed rc at which the fuel of the power source 11 can be cut off. Here, the lower limit rotational speed rc is a lower limit rotational speed that cannot be restarted even if fuel is supplied to the power source 11 when the rotational speed of the power source 11 is further decreased. Therefore, the control means 39 controls to supply fuel to the power source 11 when the rotation speed of the clutch means 13 detected by the rotation sensor (not shown) reaches the lower limit rotation speed rc.

  When the rotational speed of the clutch means 13 becomes smaller than the lower limit rotational speed rc, the control means 39 controls the clutch means 13 so as to separate the power source 11 and the transmission means 15 from each other. Specifically, the lockup mechanism of the clutch means 13 is turned off. As a result, the power source side rotational speed quickly decreases as shown by the thick solid line in FIG. 2B, and when the idling rotational speed ri is reached, the rotational speed is maintained. At this time (from time t4 to time t5), the speed change means side rotation speed of the clutch means 13 is higher than the power source side rotation speed, so the generator 21 is driven by the speed change means side pulley 25. Therefore, the kinetic energy by the braking is continuously regenerated. As a result, as shown in FIG. 2 (c), the power generation amount remains the same as that until time t4, and as shown in FIG. 2 (d), the input power of the DC / DC converter 35 is also until time t4. Maintain the same state. As a result, the power storage means 37 continues to be charged, and the amount of power storage increases until time t5 as shown in FIG.

  Here, the deceleration of the wheel 17 at the times t3 to t5 described above shows the case of traveling on flat ground, but at the time of uphill, the rotational torque from the power source 11 is used even though the vehicle speed is decreasing. The wheel 17 may rotate. In this case, kinetic energy due to deceleration cannot be regenerated. However, in the first embodiment, even when the vehicle is climbing up, when the power source 11 rotates with the rotational torque from the wheel 17, the speed changer side rotation speed due to the rotation of the wheel 17 becomes high, and the rotation speed selection means 19. Thus, the rotational torque from the wheel 17 can be automatically taken out. Therefore, it is possible to obtain regenerative power even when the climbing state is caused from coasting on the flat ground, and the efficiency is improved.

  Next, it is assumed that the power source side rotational speed (thick solid line) becomes higher than the transmission means side rotational speed (thick dotted line) as shown in FIG. At this time, as shown in FIG. 2A, the vehicle speed has not reached 0, so the vehicle is traveling slowly. Thereby, the rotation speed selection means 19 takes out the rotation torque from the higher rotation speed, that is, the power source 11 side, and transmits it to the generator 21. As a result, the generator 21 is driven by the power source 11, and regenerative power can no longer be obtained. Therefore, when the wheel 17 is decelerated, the control means 39 uses the rotation sensors (not shown) provided in the vicinity of the transmission means side pulley 25 and the power source side pulley 23 to change the transmission means side rotation speed and the power source side rotation speed, respectively. It detects and controls to stop the power generation of the generator 21 at the time t5 when the former becomes lower than the latter. Specifically, the excitation current to the generator 21 is stopped. Thereby, as shown in FIG.2 (c), the electric power generation amount of the generator 21 becomes zero.

  At the same time, the control means 39 controls the DC / DC converter 35 so that the regenerative power charged in the power storage means 37 is discharged. At this time, since the current consumed by the electrical load 33 is constant as described above, the power output from the DC / DC converter 35 is also constant as shown after time t5 in FIG. In FIG. 2D, since the vertical axis represents the input power of the DC / DC converter 35, when power is output from the DC / DC converter 35, it is shown as negative input power.

  As described above, by discharging the regenerative power, it is possible to supply power to the electric load 33 even when the generator 21 is stopped. Therefore, the regenerative power can be used effectively without stopping the electric load 33, and fuel efficiency can be improved. Furthermore, since the generator 21 is stopped, the mechanical burden for driving the generator 21 of the power source 11 is reduced, so that fuel efficiency can be improved.

  Thus, since the regenerative power charged in the power storage means 37 after time t5 is discharged to the electric load 33, the amount of power stored in the power storage means 37 decreases with time as shown in FIG. 2 (e). Go.

  Next, as shown in FIG. 2A, it is assumed that the vehicle speed becomes 0 and the wheel 17 stops at time t6. As a result, the speed change means side pulley 25 connected to the wheel 17 is also stopped, so that the speed change speed on the speed change means side becomes zero at time t6, as indicated by the thick dotted line in FIG. At this time, as shown in FIG. 2 (e), the amount of electricity stored in the electricity storage means 37 is still sufficiently high, so that the control means 39 continues to operate the DC / DC converter 35 to supply the electric power of the electricity storage means 37 to the electric load 33. Supply. Therefore, as shown in FIG. 2D, the input power of the DC / DC converter 35 maintains a negative constant value, and the power storage means 37 continues to be discharged. As a result, since the generator 21 does not need to generate power, the power generation remains stopped as shown in FIG.

  Thereafter, it is assumed that the vehicle once stopped at time t6 but immediately re-accelerated. Thereby, as shown to Fig.2 (a), a vehicle speed rises again after time t6. When the driver depresses the accelerator pedal by this reacceleration, both the power source side rotational speed and the transmission means side rotational speed increase with time as shown in FIG. Immediately after time t6, the power source side rotational speed is higher than the transmission means side rotational speed, but this state is the same as immediately after time t1.

  However, the difference from immediately after time t 1 is the power supply to the electric load 33. That is, immediately after the time t6, as shown in FIG. 2 (e), the amount of electricity stored in the electricity storage means 37 is still sufficiently high, so the input power of the DC / DC converter 35 is negative as shown in FIG. 2 (d). Is maintained, and the power storage means 37 is discharged. As a result, power is continuously supplied to the electric load 33. Therefore, the generator 21 remains stopped as shown in FIG. Therefore, since the mechanical load of the generator 21 is hardly applied to the power source 11 even at the time of reacceleration, an effect of improving the acceleration performance can be obtained.

  Although the subsequent operation is not shown in the figure, basically, if the amount of power stored in the power storage unit 37 decreases and the constant power cannot be supplied from the DC / DC converter 35 to the electric load 33, the control unit 39 controls the DC / DC converter 35. Is controlled so that the power generation of the generator 21 is resumed. Thereby, since the electric load 33 continues to be supplied with the electric power of the generator 21, it can continue to operate. Since this state is the same as the time t0 to the time t1 in FIG. 2, the operation of the generator 21 during the deceleration of the wheel 17 and the discharging of the power storage unit 37 is repeated by repeating such an operation thereafter. By stopping the vehicle, the fuel efficiency of the vehicle can be improved.

  In addition, if it will be in the deceleration state after the electrical storage means 37 is discharging after time t6, the same operation | movement as time t3 should just be performed immediately. Thereby, the collection amount of regenerative electric power at the time of deceleration can be increased. However, when the power storage means 37 reaches full charge, control for stopping further charge is performed in order to protect the electric double layer capacitor.

  Here, the control of the clutch means 13 described so far is summarized as follows. The control means 39 engages between the power source 11 and the transmission means 15 when the speed of the wheel 17 is reduced and the power source side rotational speed is equal to or higher than the lower limit rotational speed rc at which the fuel of the power source 11 can be cut off. If it is smaller than rc, the clutch means 13 is controlled so that the power source 11 and the speed change means 15 are separated.

  By controlling in this way, as shown in FIG. 2 (b), the transmission means side rotational speed becomes higher than the power source side rotational speed from time t4 to time t5. As a result, the rotational speed selection means 19 extracts rotational torque from the higher one of the power source side rotational speed and the speed change means side speed, that is, the speed change means 15 side, and transmits it to the generator 21. Therefore, the generator 21 is rotated by the wheel 17 via the speed change means 15. At this time, the speed change means 15 is in a low gear or second gear state as described above. Here, the ratio of the rotational speed on the clutch means 13 side to the rotational speed on the wheel 17 side of the speed change means 15 (hereinafter referred to as the speed ratio) is greater than 1 for both the low gear and the second gear. Therefore, the generator 21 is driven by the speed change means 15 at a higher rotational speed than the rotational speed of the wheel 17. As a result, even if the rotational speed of the wheel 17 is reduced, the rotational speed is increased by the transmission means 15, so that sufficient regenerative power can be obtained even if the wheel 17 rotates at a low speed due to traffic jams.

  With the configuration and operation described above, the configuration is such that the rotational torque of the wheel 17 is transmitted to the generator 21 via the transmission means 15 and the rotational speed selection means 19, so that the transmission means 15 Since the rotational speed higher than the rotational speed is obtained, the rotational speed selection means 19 extracts rotational torque from the higher one of the power source side rotational speed and the transmission means side rotational speed, and transmits the rotational torque to the generator 21. Even when rotating at a low speed, a higher rotational speed than the wheel 17 is transmitted to the generator 21. Therefore, it is possible to realize a braking force regeneration device that can obtain sufficient regenerative power and improve fuel efficiency.

  In the first embodiment, when the wheel 17 is decelerated, the control means 39 engages between the power source 11 and the transmission means 15 if the power source side rotational speed is equal to or higher than the lower limit rotational speed rc, and the lower limit rotational speed. If it is smaller than rc, the clutch means 13 is controlled so that the power source 11 and the transmission means 15 are separated from each other. However, if the power storage means 37 has a sufficiently large capacity, if the wheel 17 decelerates, The power source 11 and the speed change means 15 may be controlled to be separated. Thereby, since the clutch means 13 performs the separation operation at time t3 in FIG. 2, the period during which the power source 11 is rotated by the wheel 17 becomes extremely short. Therefore, energy (friction loss, pumping loss, etc.) consumed by the power source 11 at the time of deceleration can be reduced, and the generator 21 can be rotated by the wheel 17 for a long time. Therefore, since the amount of regenerative electric power can be increased, it is possible to fully utilize the storage capacity of the large-capacity storage means 37.

  However, when the clutch means 13 is controlled in this way, so-called engine braking is hardly obtained. Therefore, when engine braking such as downhill is necessary, the above control is not performed, and time t4 to time t4 in FIG. It is sufficient to perform the control in step (b). As for the downhill determination method, for example, it may be determined that the vehicle is downhill when the vehicle speed is constant or increases even though the accelerator pedal is not depressed.

  Further, when the control for separating the power source 11 and the speed change means 15 is performed along with the deceleration of the wheel 17 as described above, the rotational speed of the power source 11 sharply decreases, so the time until the lower limit rotational speed rc is reached. The fuel cutoff time is shortened. Therefore, if the clutch means 13 is separated early at the time of deceleration, the regenerative electric energy increases, so that the driving time of the generator 21 is shortened and the fuel efficiency is improved. On the other hand, the fuel efficiency improvement effect is reduced by shortening the fuel cutoff time. . Therefore, it is desirable to separate the clutch means 13 at the timing when the fuel efficiency is the best. For this purpose, for example, the control means 39 predicts how much regenerative power can be stored according to the current power storage amount of the power storage means 37, and the clutch means 13 is separated at such a timing that the regenerative power amount can be recovered. Can be done. Thereby, the fuel consumption can be further improved.

  In the first embodiment, the clutch means 13 is a torque converter with a lockup mechanism, but this may be a torque converter without a lockup mechanism. In this case, although the power source side rotational speed and the transmission means side rotational speed approach from time t2 to time t4 in FIG. However, the operation is the same as in FIG. 2 except that the on / off control of the lockup mechanism is not required.

  In the first embodiment, the automatic transmission that switches the gear ratio by hydraulic pressure is used as the transmission means 15, but this may be a continuously variable transmission.

  Further, the clutch means 13 and the transmission means 15 may be a two-pedal manual transmission. In this case, since the clutch means 13 is automated, the control means 39 can engage and disengage the clutch means 13. Therefore, the operation shown in FIG. 2 is possible, and fuel consumption can be improved.

(Embodiment 2)
FIG. 3 is a time-dependent change diagram of various characteristics of the braking force regeneration device according to Embodiment 2 of the present invention, (a) is a time-dependent change diagram of the vehicle speed, and (b) is a time-dependent change diagram of the rotational speed of the clutch means. (C) is a time-dependent change diagram of the power generation amount, (d) is a time-change graph of the DC / DC converter input power, and (e) is a time-change graph of the power storage means power storage amount. Note that the horizontal axes in FIGS. 3A to 3E are all time. In the second embodiment, a case where a generator is used as an auxiliary machine will be described.

  Since the configuration of the braking force regeneration device in the second embodiment is the same as that of FIG. 1 described in the first embodiment, detailed description thereof will be omitted, and the operation that characterizes the second embodiment will be described below. explain.

  In the second embodiment, the operation when the vehicle is traveling normally when it is not congested will be described. First, the operation of accelerating when the vehicle is stopped is basically the same as the time t0 to time t3 shown in FIG. However, since it is during normal driving, the vehicle speed is higher than during traffic jams. Therefore, at time t3 in FIG. 2, the transmission means 15 is in the state of selecting the highest gear. Therefore, the gear ratio is a minimum value less than 1, and the clutch means 13 is engaged by the lockup mechanism.

  This state is assumed to be time t10 in FIG. That is, at time t10, as shown in FIGS. 3A and 3B, the vehicle speed and the rotational speed of the clutch means 13 are large. Further, since the clutch means 13 is engaged, the power source side rotational speed and the transmission means side rotational speed coincide with each other as shown in FIG.

  It is assumed that at time t10, the driver turns off the accelerator pedal and starts deceleration of the vehicle. As a result, as shown in FIGS. 3A and 3B, the vehicle speed and the rotational speed of the clutch means 13 decrease with time from time t10. At this time, when the control means 39 detects an accelerator off signal, a decrease in vehicle speed, and a decrease in the rotational speed of the clutch means 13 detected by a rotation sensor (not shown), it is determined that the vehicle is decelerating, and the transmission means 15 Is shifted down to, for example, a third (third speed) gear. Further, the control means 39 cuts off the fuel supply to the power source 11 and controls the generator 21 to increase the amount of power generation as much as the power storage means 37 is charged with regenerative power. As a result, as shown in FIG. 3C, the power generation amount increases at time t <b> 10, and power is supplied to the electric load 33 and the power storage unit 37. At the same time, in order to charge the power storage means 37 with regenerative power, control is performed so that the input power of the DC / DC converter 35 becomes a constant value. By this operation, regenerative power is charged in the power storage means 37, and the amount of power stored in the power storage means 37 increases with time as shown in FIG. These operations are the same as those in the first embodiment.

  Next, it is assumed that the rotational speed of the clutch means 13 reaches the lower limit rotational speed rc at time t11. The meaning of the lower limit rotational speed rc is the same as in the first embodiment. At this time, the control means 39 resumes the fuel supply to the power source 11 and separates the power source 11 and the transmission means 15 from each other. As a result, as indicated by the thick solid line in FIG. 3B, the power source side rotational speed quickly decreases, reaches the idling rotational speed ri at time t12, and thereafter maintains the idling rotational speed ri. During this time, the speed of the transmission means side gradually decreases with the rotation of the wheel 17 as indicated by the thick dotted line in FIG. 3 (b), but the rotation continues, so FIGS. ), The charging of the regenerative power generated by the generator 21 to the power storage means 37 is also continued.

  Thereafter, as indicated by the thick dotted line in FIG. 3B, the speed of the transmission means side reaches the idling speed ri at time t13. In this state, the rotational speed of the power source 11 is transmitted to the generator 21 by the rotational speed selector 19 because the rotational speed on the power source side is higher than the rotational speed on the transmission means side. Therefore, at time t13, it is no longer possible to generate power due to the rotational torque of the wheels 17.

  Therefore, in the second embodiment, when the transmission means side rotational speed detected by the rotation sensor (not shown) reaches the idling rotational speed ri, the control means 39 shifts the gear down by one step with respect to the transmission means 15. To control. Specifically, until the time t13, the transmission means 15 has selected the third (third speed) gear, so the control means 39 controls the transmission means 15 to shift down to the second (second speed) gear. As a result, since the gear ratio increases, the transmission means side rotation speed suddenly increases at time t13 as shown by the thick dotted line in FIG. As a result, the speed at the transmission means side can be maintained higher than the speed at the power source side, so that the rotational torque from the wheels 17 is continuously transmitted to the generator 21 and further regenerative power can be recovered.

  After that, when the vehicle speed further decreases and the transmission means side rotational speed reaches the idling rotational speed ri at time t14 as shown by the thick dotted line in FIG. 3B, the control means 39 starts from the second (second speed) gear. The transmission 15 is controlled to shift down to the (first speed) gear. As a result, the speed ratio of the speed change means 15 is further increased at time t14, so that the speed change speed on the speed change means side is increased, and the rotational torque from the wheels 17 is continuously transmitted to the generator 21.

  In summary, the control means 39 controls the speed ratio of the speed change means 15 so that the speed of the speed change means side is higher than the speed of the power source side when the wheels 17 are decelerated. As a result, as shown in FIGS. 3C to 3E, charging of the power storage means 37 is continued from time t13 to time t15, so that more regenerative power can be recovered.

  Thereafter, as shown by the thick dotted line in FIG. 3B, when the transmission means side rotational speed reaches the idling rotational speed ri at time t15, the speed ratio of the transmission means 15 cannot be increased any more. 39 controls the generator 21 to stop power generation and at the same time controls the DC / DC converter 35 to discharge the electric power of the power storage means 37. These operations are the same as those in the first embodiment. As a result, even if the generator 21 is stopped, electric power is supplied from the power storage means 37 to the electric load 33 via the DC / DC converter 35. Thereby, as shown in FIG.3 (e), after the time t15, the electrical storage amount of the electrical storage means 37 falls.

  After that, as shown in FIG. 3A, even when the vehicle speed becomes zero at time t16 and the vehicle stops, the generator 21 is stopped from the power storage unit 37 while the power is stored in the power storage unit 37. Continue to supply power to the electrical load 33. The subsequent operations are not shown in FIG. 3, but are the same as those in the first embodiment.

  With the above configuration and operation, sufficient regenerative electric power can be obtained even when the wheel 17 rotates at a low speed, and the speed change means side speed is higher than the power source side speed when the wheel 17 is decelerated. By controlling the gear ratio of the means 15, it is possible to recover a larger amount of regenerative power and to realize a braking force regenerative device that can further improve fuel efficiency.

(Embodiment 3)
FIG. 4 is a schematic configuration diagram of a braking force regeneration device according to Embodiment 3 of the present invention. In the second embodiment, the case where a generator is used as an auxiliary machine will be described. In the configuration of the third embodiment, the same components as those in FIG. That is, the configuration that characterizes the third embodiment is as follows.

  1) The power storage means 37 was directly connected to the output of the generator 21.

  2) The battery 31 and the electric load 33 were connected to the output of the DC / DC converter 35.

  3) The voltage detection means 41 was connected to the output of the generator 21.

  4) The current detection means 43 was connected to the output of the generator 21.

  Other configurations are the same as those in FIG. The detection value outputs of the voltage detection means 41 and the current detection means 43 are input to the control means 39. Further, the current detection of the current detection means 43 is performed by a current sensor provided on the output line of the generator 21.

  Next, the operation of such a braking force regeneration device will be described.

  First, the operation of the mechanical components such as the clutch means 13, the speed change means 15, and the rotation speed selection means 19 is the same as that in the first and second embodiments, and therefore detailed description thereof is omitted. The operation of the electrical system as a feature will be described.

  When the vehicle is not in use, the generator 21 is not operating and the DC / DC converter 35 is also stopped. Therefore, the voltage of the battery 31 (set to 14 V in the normal state) and the initial voltage of the storage means 37 are They are almost equal. Therefore, the voltage of the battery 31 is maintained at least as the voltage of the power storage means 37.

  When an ignition switch (not shown) of the vehicle is turned on in this state, the power source 11 is operated, and the generator 21 starts power generation. At this time, the control means 39 performs control so that the voltage of the generator 21 is substantially equal to the initial voltage (14V) of the power storage means 37 detected by the voltage detection means 41. At the same time, the operation of the DC / DC converter 35 is also started. Thereby, the power generated by the generator 21 is not supplied to the power storage means 37 but is supplied to the battery 31 and the electric load 33 via the DC / DC converter 35. This state is maintained even when the vehicle is accelerated.

  Next, when deceleration is started by vehicle braking, the control unit 39 controls to increase the generated power of the generator 21 according to the strength of the brake and collect the regenerative power. At this time, the regenerative electric power generated is controlled by the control means 39 so as to be a constant value according to the brake strength. Therefore, the generator 21 is subjected to constant power control.

  At this time, the power generation voltage of the generator 21 is slightly higher than the voltage of the power storage means 37, so that the power generation amount increased by the regenerative power is charged in the power storage means 37. By such an operation, the regenerative power of the generator 21 is supplied to the electric load 33 via the DC / DC converter 35 and the power storage means 37 is charged. Here, as in the first embodiment, if the current consumed by the electric load 33 is constant, the surplus regenerative power is charged in the power storage means 37. The constant power control described above is performed so that the product of the output of the voltage detection means 41 and the output of the current detection means 43 becomes a predetermined constant value. With these operations, the amount of power stored in the power storage unit 37 increases with time.

  Thereafter, when the transmission means side rotational speed becomes lower than the power source side rotational speed at time t5 in FIG. 2B, the control means 39 stops the power generation of the generator 21. Thereby, the electric power of the electric storage means 37 is stepped down by the DC / DC converter 35 and supplied to the electric load 33. As a result, while the generator 21 is stopped, the mechanical burden on the power source 11 is reduced and the regenerative power is supplied to the electric load 33, so that the fuel efficiency of the vehicle can be improved.

  The control means 39 detects the voltage of the power storage means 37 with the voltage detection means 41, and discharges the power storage means 37 until the initial voltage (14V) is reached. The state where the voltage of the power storage means 37 is the initial voltage is 0% of the power storage amount. When the initial voltage is reached, the control means 39 restarts the generator 21 so that the generated voltage is substantially equal to the voltage of the power storage means 37. Thus, the generated power is not charged in the power storage means 37 but supplied to the electric load 33 via the DC / DC converter 35.

  By repeating such an operation, the regenerative power generated during braking can be used effectively each time, and fuel consumption can be improved.

  With the configuration and operation of FIG. 4 described above, the regenerative electric power at the time of deceleration is directly charged in the power storage means 37. At this time, since the regenerative power is about several kW, when the charging voltage of the power storage unit 37 is several tens of volts, a current of about several hundreds of A flows through the power storage unit 37. When this current is applied in the configuration shown in FIG. 1 of the first embodiment, a large current flows through the DC / DC converter 35, and the loss due to the internal resistance increases, but FIG. If it is a structure, since the electrical storage means 37 can be directly charged without going through the DC / DC converter 35, a low-loss braking force regeneration device can be obtained even if a large current flows.

  Further, in the configuration of FIG. 1, since charging / discharging of the power storage means 37 is controlled by the DC / DC converter 35, it is necessary to configure a bidirectional converter, but in the configuration of the third embodiment, DC / DC Since the converter 35 allows current to flow only to the electric load 33 side, a simpler configuration and control can be achieved.

  With the above configuration and operation, as in the first and second embodiments, sufficient regenerative power can be obtained even when the wheel 17 rotates at a low speed, and the generator 21 and the power storage means 37 are directly connected. A loss due to the DC converter 35 is small, and a braking force regeneration device with a simple configuration and control can be realized.

  In the first to third embodiments, the case where the generator 21 is used as an auxiliary device has been described. However, the configuration is not limited thereto, and a configuration in which a compressor, a hydraulic pump, or the like is connected to the output of the rotation speed selection unit 19 may be employed. . Also by this, even if the wheel 17 is rotating at a low speed during deceleration, a sufficient pressure is obtained by regeneration, and the burden on the power source 11 is reduced, so that fuel efficiency can be improved. Furthermore, a configuration may be adopted in which a plurality of generators 21, compressors, hydraulic pumps, and the like are simultaneously connected to the output of the rotation speed selection means 19. In this case, since the burden on the power source 11 during deceleration is further reduced, fuel efficiency is further improved.

  In the first to third embodiments, the electric double layer capacitor is used as the power storage unit 37, but this may be another capacitor such as an electrochemical capacitor.

  Further, the braking force regeneration devices of the first to third embodiments can be applied to an auxiliary power source for vehicles in each system such as a hybrid vehicle, an idling stop, an electric power steering, a vehicle braking system, and an electric supercharger.

  The braking force regeneration device according to the present invention is useful as a braking force regeneration device for a vehicle that recovers kinetic energy by driving an auxiliary device at the time of deceleration because sufficient regeneration is obtained even when the wheel rotates at a low speed. It is.

1 is a schematic configuration diagram of a braking force regeneration device according to Embodiment 1 of the present invention. It is a time-dependent change figure of the various characteristics of the braking force regeneration apparatus in Embodiment 1 of this invention, (a) is a time-dependent change figure of a vehicle speed, (b) is a time-dependent change figure of the rotation speed of a clutch means, (c) is a time-dependent change figure. (D) is a time-dependent change diagram of DC / DC converter input power, (e) is a time-dependent change diagram of power storage means power storage amount. FIG. 4 is a time-dependent change diagram of various characteristics of the braking force regeneration device according to Embodiment 2 of the present invention, (a) is a time-dependent change diagram of vehicle speed, (b) is a time-dependent change diagram of the rotational speed of the clutch means, and (c) is a time-dependent change diagram. (D) is a time-dependent change diagram of DC / DC converter input power, (e) is a time-dependent change diagram of power storage means power storage amount. Schematic block diagram of the braking force regeneration device in Embodiment 3 of the present invention Overall configuration diagram of a conventional auxiliary drive unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Power source 13 Clutch means 15 Transmission means 17 Wheel 19 Rotation speed selection means 21 Generator 35 DC / DC converter 37 Power storage means 39 Control means

Claims (9)

A power source that generates rotational torque;
Clutch means connected to the power source and controlling transmission of the rotational torque;
Transmission means connected to the clutch means;
Wheels connected to the transmission means;
A rotational speed selection means connected to the clutch means and for extracting the rotational torque from the higher power source side rotational speed of the clutch means and the transmission means side rotational speed of the clutch means;
A braking force regeneration device comprising an auxiliary machine connected to the rotation speed selection means and to which the rotation torque taken out by the rotation speed selection means is transmitted. A control means is connected to the speed change means,
2. The control according to claim 1, wherein the control means controls a speed ratio of the speed change means so that the speed of the speed change means side is higher than the speed of the power source side when the wheel is decelerated. Power regeneration device. A control means is connected to the clutch means,
The braking force regeneration device according to claim 1, wherein the control means controls the clutch means so that the power source and the speed change means are separated when the wheel is decelerated. A control means is connected to the clutch means,
The control means engages between the power source and the speed change means when the speed of the wheel is decelerated and the power source side rotational speed is equal to or higher than a lower limit rotational speed at which the fuel of the power source can be cut off. The braking force regeneration device according to claim 1, wherein the clutch means is controlled so that the power source and the speed change means are separated from each other if the number is smaller than the number. The power source has a configuration in which a control means is connected,
The braking force regeneration device according to claim 1, wherein the control means controls the power source to stop when the wheel is decelerated. The braking force regeneration device according to claim 1, wherein the auxiliary machine is a generator, and the generator is connected to power storage means for storing generated power. A DC / DC converter is connected between the generator and the power storage means,
The braking force regeneration device according to claim 6, wherein the DC / DC converter charges the power storage means with the electric power generated by the generator when the wheel is decelerated. The braking force regeneration device according to claim 6, wherein the power storage means is a capacitor. The generator has a configuration in which control means is connected,
The braking force regeneration device according to claim 6, wherein the control means stops the power generation of the generator if the speed change means side rotation speed becomes lower than the power source side rotation speed during deceleration of the wheel.

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