JP3764795B2 - Vehicle deceleration energy regeneration device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for regenerating deceleration energy of a vehicle by generating electricity during braking of the vehicle.
[0002]
[Prior art]
Regarding the technology for regenerating deceleration energy of a vehicle, there are many proposals including, for example, Japanese Patent Application Laid-Open No. 8-40248.
[0003]
By the way, although the engine of a vehicle is equipped with the electric power generating apparatus in order to charge a battery, charging to a battery is performed when this falls below predetermined value, detecting a battery voltage, and an electric power generating apparatus is carried out. The engine load to drive is reduced.
[0004]
[Problems to be solved by the invention]
However, conventionally, charging is performed regardless of the running state of the vehicle, and there is no idea of actively charging the battery using deceleration energy of the vehicle during braking, and the deceleration energy of the vehicle is wasted. Was consumed.
[0005]
It is an object of the present invention to enhance energy saving by operating a power generation device during braking of a vehicle to charge a battery and utilizing this during acceleration.
[0006]
[Means for Solving the Problems]
The present invention relates to an alternator that is rotationally driven by an engine, a battery that is supplied with electric power generated by the alternator, and a load, and means for detecting brake operation of the vehicle, and a field coil of the alternator when detecting brake operation. A first relay circuit that is energized, a comparison reference voltage generation circuit that generates a reference voltage according to the battery temperature, a voltage comparison switch circuit that is turned on when the battery terminal voltage is lower than the reference voltage, and this voltage comparison A second relay circuit that bypasses the first relay circuit and energizes the field coil when the switch circuit is turned on, and generates the alternator until the battery capacity reaches 100% during deceleration with the brake applied. A vehicle deceleration energy regeneration device.
[0008]
According to a second aspect of the present invention, the resistance reference voltage of the battery through the thermistor is input to the comparison reference voltage generation circuit.
[0009]
[Operation and effect of the invention]
In the first invention, when the deceleration state of the vehicle applied with the brake is detected by the brake operation detecting means, the first relay circuit is operated to energize the field coil of the alternator. When the vehicle decelerates, the vehicle travels inertially due to the inertial energy of the vehicle, and the engine is also rotated by inertia. As a result, the alternator is generated, and when the vehicle is decelerated, the power load is small.
[0010]
In this way, since the deceleration energy of the vehicle is recovered in the deceleration state with the brake applied and the battery is charged, the energy can be saved by utilizing this during acceleration or the like.
[0011]
In addition , since the comparison reference voltage for controlling the power generation by the alternator is changed according to the battery temperature state, it is possible to generate power in accordance with the battery charging request, thereby preventing unnecessary power generation and reducing the engine load.
[0012]
In the second aspect of the invention, an output voltage that accurately corresponds to the battery temperature is obtained by the thermistor, and the power generation control of the alternator can be accurately performed with a simple configuration.
[0013]
Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
In FIG. 1, 1 is an engine key switch, 2 is a regulator, and 3 is a battery. In the regulator 2, the exciting force of the coil 2a changes in accordance with the potential of the A terminal, and the contact P2 is connected to P1, connected to the contact P3, or switched to a state in which neither is connected.
[0015]
Reference numeral 4 denotes an alternator for power generation, and as shown in FIG. 7, the rotation of the engine crankshaft 21 is transmitted via the belt 22 and is driven to rotate in synchronization with the engine rotation.
[0016]
The alternator 4 is composed of a field coil 5a, a stator coil 5b, and a rectifying diode 5c. When the stator coil 5b rotates while the field coil 5a is energized, power is generated and rectified via the diode 5c. And a current is supplied to the load 10.
[0017]
6 is a charge relay, 7 is a charge lamp, and the coil 6a of the charge relay 6 is connected to the neutral point of the stator coil 5b. When power generation is stopped, the contacts P4 and P5 are connected, and the neutral point is generated by power generation. When the potential increases and the coil current increases, the contacts P5 and P6 are connected.
[0018]
Reference numeral 11 denotes a brake switch for detecting a deceleration state of the vehicle when the brake is applied. The brake switch 11 is turned on when the brake is applied, thereby operating the brake relay 12. When the brake relay 12 is energized to the coil 12a, the contacts P7 and P8 are connected, current is supplied from the terminal Fr to the field coil 5a, and the alternator 4 generates power. However, when the coil 12a is not energized, the contact P8 Connected with P9 and disconnected.
[0019]
Reference numeral 15 denotes a comparison reference voltage generation circuit to which a voltage corresponding to a voltage dividing resistor by the thermistor 14 for detecting the battery temperature is input from the battery 3, and an output Vs corresponding to the input voltage is input as a reference voltage of the voltage comparison switch circuit 16. .
[0020]
The voltage comparison switch circuit 16 compares the output voltage Vb of the battery 3 with the reference voltage Vs. When Vb ≦ Vs, the voltage comparison switch circuit 16 is switched on and energizes the coil 13 a of the voltage detection relay 13. When the voltage detection relay 13 is energized to the coil 13a, the contacts P10 and P11 are connected, current is supplied from the terminal Fr to the field coil 5a, and the alternator 4 generates power.
[0021]
In contrast, when the output voltage Vb of the battery 3 is lower than the reference voltage Vs and the coil 13a is not energized, the contacts P11 and P12 are connected. The contact P12 is connected to the contact 9.
[0022]
Next, the operation will be described with reference to FIG.
[0023]
When the vehicle is accelerating or at a constant speed, the brake switch 11 is off, the contacts P7 and P8 of the brake relay 12 are disconnected, and the terminals Fr and F are opened.
[0024]
At this time, when the voltage at the terminal Fr exceeds the voltage Vs necessary for the next engine start-up, that is, when the battery voltage is higher than the reference voltage from the comparison reference voltage generation circuit 15, the voltage comparison switch circuit. 16 is turned off and the contacts P10 and P11 of the voltage detection relay 13 are cut off, so the voltage at the terminal F of the alternator 4 becomes zero and no current flows through the field coil 5a. Yes. In this state, the load 10 is covered by the battery 3.
[0025]
When the alternator 4 is not generating power, the load on the engine is greatly reduced.
[0026]
When the voltage of the battery 3 decreases and the terminal voltage becomes Vs or less, the voltage comparison switch circuit 16 is turned on, the coil 13a of the voltage detection relay 13 is energized, and the contacts P10 and P11 are connected.
[0027]
For this reason, a current flows from the terminal Fr through the contacts P10 and P11 and further through the contacts P9 and P8 to the terminal F, the field coil 5a is energized, and the alternator 4 generates power.
[0028]
The power generation of the alternator 4 is performed while detecting the terminal voltage of the battery 3. For example, the voltage comparison switch circuit 16 is repeatedly turned on and off so as to maintain the voltage Vs at which the battery capacity becomes 70%. In response, power is generated and the battery 3 is charged and discharged.
[0029]
This state is a section from t1 to t2 in FIG. Now, assume that the engine is temporarily stopped at t2 and started again at t3.
[0030]
In the period from t2 to t3, the battery 3 is consumed by the previous engine start-up, the capacity is reduced to 60% or less, and the voltage is also reduced to Vk.
[0031]
When the vehicle shifts to acceleration or constant speed driving after starting, since the terminal voltage Vb of the battery 3 is lower than Vs, the voltage comparison switch circuit 16 is turned on, the voltage detection relay 13 is activated and the field coil 5a of the alternator 4 is energized. , Power generation continues. As a result, charging of the battery 3 and supply of current to the load 10 are performed, and the voltage of the battery 3 gradually increases during this time.
[0032]
When the terminal voltage of the battery 3 reaches the reference voltage Vs at t4, the voltage comparison switch circuit 16 is repeatedly turned on and off in the same period as before, and the battery 3 maintains a capacity of 70%. .
[0033]
When the vehicle is braked at t5 and transitions to the deceleration state, the brake switch 11 is turned on, the brake relay 12 is activated, the coil 12a is energized, and the contacts P7 and P8 are connected. As a result, the terminals Fr and F are connected, current flows through the field coil 5a, and the alternator 4 generates power.
[0034]
In this case, even if the voltage comparison switch circuit 16 is turned off by comparing the terminal voltage of the battery 3 with the reference voltage, and the contacts P10 and P11 of the voltage detection relay 13 are cut off, the terminals Fr and F remain connected. Therefore, energization to the field coil 5a is continued. Therefore, the battery 3 is charged until the battery capacity reaches 100%, and deceleration energy of the vehicle is recovered in the form of charging of the battery 3 during braking. This is performed for the deceleration zone from t5 to t8.
[0035]
In this way, at the time of deceleration with the brake applied, regeneration of deceleration energy of the vehicle is performed.
[0036]
The power generation voltage of the alternator 4 varies depending on the rotation speed of the alternator 4, but is maintained at a specified value by the regulator 2 adjusting the energization current of the field coil 5a.
[0037]
When the potential of the neutral point of the stator coil 5b increases with the power generation of the alternator 4, the charge relay 6 is operated to switch from the contact P5 to P6, thereby energizing the coil 2a of the regulator 2.
[0038]
The exciting force of the coil 2a changes according to the voltage at the terminal A, the contact P2 is selectively switched between the contacts P2 and P3, and the field coil 5a is selectively connected by the resistors R1 and R2 that are selectively interposed. To control the current to.
[0039]
That is, when the potential at the A terminal is low and the contacts P1 and P2 are connected as shown in the figure, the current flowing through the field coil 5a increases and the amount of power generation increases. As a result, when the potential at the A terminal is increased, the contact point P2 is not in contact with the coil 2a. At this time, the field coil 5a is energized via the resistor R1, so that the field coil current is decreased. When the potential of the terminal is maximized, the contact P2 is connected to the contact P3. At this time, the current flowing through the field coil 5a is minimized, and the power generation amount decreases.
[0040]
As a result, when the voltage at the terminal A reaches V2, the current of the field coil 5a is weakened, and when it becomes V1 or less, the current is strengthened, and the voltage at the terminal A is adjusted in this way.
[0041]
Next, in this embodiment, as described above, the resistance divided value by the thermistor 14 is input to the comparison voltage generation circuit 15, and the reference voltage Vs is changed according to the temperature state of the battery 3 based on this. .
[0042]
Even when the battery 3 has a capacity necessary for starting the engine, such as when the engine is started, the terminal voltage changes depending on the battery temperature. FIG. 3 shows the relationship between battery temperature and minimum starting battery voltage. Here, the safe minimum voltage Vs is a voltage characteristic when the battery capacity is 70%, and the actual minimum voltage Vk is a minimum necessary voltage characteristic.
[0043]
Therefore, if the reference voltage Vs of the voltage comparison switch circuit 16 is a constant value, when the battery terminal voltage Vb changes due to temperature, the voltage comparison switch circuit 16 is turned on even if charging is not actually required, and the alternator 4 generates power. As a result, the amount of the load is added as an engine load.
[0044]
However, since the thermistor 14 adjusts the reference voltage Vs while detecting the temperature of the battery 3, such a problem is avoided.
[0045]
As it is in FIG. 4, the resistance value of the thermistor r _T varies depending on the battery temperature T _B, the resistance as the temperature increases is reduced. Then, as shown in FIG. 5, the generated voltage V _T of the thermistor 14 increases in proportion to the battery voltage T _B.
[0046]
Thus, by entering the resistor divider V _T of the thermistor 14 to the reference voltage generating circuit 15, as shown in Figure 6, by outputting the reference voltage Vs in accordance with this, always properly according to the battery temperature In other words, the alternator 4 can generate power only when necessary.
[0047]
Therefore, unnecessary power generation by the alternator 4 can be prevented, the engine load can be reduced by that much, and fuel consumption can be improved.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing power generation characteristics corresponding to an operating state.
FIG. 3 is a characteristic diagram showing the relationship between battery temperature and minimum starting voltage.
FIG. 4 is a characteristic diagram showing temperature characteristics of the thermistor.
FIG. 5 is a characteristic diagram showing the relationship between the generated voltage of the thermistor and the battery temperature.
FIG. 6 is a characteristic diagram showing a relationship between a generated voltage of the thermistor and a reference voltage.
FIG. 7 is an engine front view showing an attached state of the alternator.
[Explanation of symbols]
3 Battery 4 Alternator 5a Field coil 5b Stator coil 10 Load 11 Brake switch 12 Brake relay 13 Voltage detection relay 14 Thermistor 15 Comparison reference voltage generation circuit 16 Voltage comparison switch circuit

Claims (2)

In a vehicle equipped with an alternator that is rotationally driven by an engine, a battery to which electric power generated by the alternator is supplied, and a load,
Means for detecting braking of the vehicle;
A first relay circuit that energizes the field coil of the alternator when the brake operation is detected ;
A comparison reference voltage generation circuit for generating a reference voltage according to the battery temperature;
A voltage comparison switch circuit that is turned on when the battery terminal voltage is lower than the reference voltage;
A second relay circuit that bypasses the first relay circuit and energizes the field coil when the voltage comparison switch circuit is on,
A deceleration energy regeneration device for a vehicle, wherein the alternator is configured to generate electric power until the battery capacity reaches 100% during deceleration with the brake applied. The deceleration energy regeneration device for a vehicle according to claim 1 , wherein a resistance partial pressure of a battery through a thermistor is input to the comparison reference voltage generation circuit.

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