JPH11220804A - Regenerative brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerative brake that is simple in structure and can be easily mounted later. SOLUTION: A regenerative brake 20 is provided with a brake caliper 10 for achieving braking by performing the press contact of a brake pad 2 to a rotary part 1, a heat pipe 3 that is connected to the brake caliper 10, a thermoelectric conversion element 4 that is connected to the radiation side edge of the heat pipe 3, cooling equipment 5 that is connected to the cooling side surface of the thermoelectric conversion element 4, and a rechargeable battery 6 that is connected to the thermoelectric conversion element 4. Therefore, heat being generated by the brake 20 is converted to electricity by the thermoelectric conversion device 40 for collecting the kinetic energy of a vehicle, thus simplifying a structure as compared with the use of a rotary generator, miniaturizing a device and reducing its weight, and at the same time reducing costs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a regenerative braking device for recovering kinetic energy.

[0002]

2. Description of the Related Art In recent years, improvement of automobiles has been demanded from the viewpoint of environmental problems and energy problems. Therefore, the development of a gasoline direct injection engine for saving fuel consumption and the development of electric vehicles and hybrid vehicles for the purpose of reducing exhaust gas have been successively performed.

[0003] In addition, there has been proposed an apparatus that collects kinetic energy of a vehicle at the time of braking of the vehicle, converts the kinetic energy into electrical energy or mechanical energy, and stores the energy. Many of them
The mainstream is to rotate a generator using the rotational energy of wheels and charge the battery with the generated power.

[0004]

However, as described above, in a system for recovering energy by turning a generator, except for a pure electric vehicle, a generator for power generation and a generator connected to a drive system. A clutch mechanism for controlling the clutch and an electronic control device for controlling the clutch and the like are indispensable, and a considerable amount of equipment is required as a whole.

[0005] This leads to an increase in product cost and an increase in vehicle weight. Further, since a fundamental design change of the drive system of the vehicle is inevitable, it is difficult to retrofit or apply the vehicle to a vehicle under production.

In addition, the mechanism incorporating the regenerative braking device becomes complicated, so that the possibility of failure increases. The present invention has been made to solve such a conventional problem, and has as its technical object to provide a regenerative brake device that has a simple structure and is easily retrofitted.

Another object of the present invention is to provide a regenerative braking device capable of efficiently recovering the kinetic energy of a vehicle.

[0008]

SUMMARY OF THE INVENTION The present invention is a regenerative braking device, and is configured as follows to solve the above-mentioned technical problem.

That is, a brake device 20 for braking a vehicle, and a thermoelectric conversion device 40 connected to the brake device 20 for converting heat energy into electric energy
And a storage battery 6 connected to the thermoelectric conversion device 40.

The thermoelectric conversion device 40 includes a heat pipe 3 connected to the brake device 20, a thermoelectric conversion element 4 connected to a heat radiation side end of the heat pipe 3, and a thermoelectric conversion element 4 connected to a cooling side surface of the thermoelectric conversion element 4. And a radiator 5 that performs the heat treatment.

Hereinafter, important components of the present invention will be further described. [Brake Apparatus 20] As the brake apparatus 20, an apparatus for applying a brake by pressing the brake pad 2 on the rotating section 1 can be exemplified.

The rotating portion 1 is a portion of a brake device provided in a vehicle or an industrial machine, and is provided in a portion to be stopped. The rotating unit 1 is, for example, a disk or a brake drum that rotates integrally with a wheel in a vehicle.

The brake pad 2 is pressed against the rotating unit 1 to stop the rotation of the rotating unit 1.
When the rotating portion 1 is a brake drum, it is called a brake shoe, but is substantially the same. [Heat Pipe 3] The heat pipe 3 is a device that transmits heat energy at a very high speed and with low loss. For example, a glass fiber or mesh-like thin copper wire bundle is put into an aluminum or stainless steel pipe, and Freon or ammonia is used. The heat medium is sealed. This heat pipe 3
When heating one end (heat absorbing end) of the pipe, the heat medium is vaporized and moves to the other end (radiating end) at a speed close to the speed of sound. Then, the heat medium that has moved to the other end of the pipe is cooled and condensed, and moves to one end again by capillary action. By repeating this, a thermal conductivity about 1000 times that of metal is obtained. Particularly high performance devices are capable of transmitting 100 W of thermal energy per square centimeter of cross-sectional area.

One end of the heat pipe 3 is thermally connected to the brake pad 2 (brake device 20).
That is, it is not always necessary to make direct contact, and for example, it may be brought into contact with a piston, a housing or the like which is in contact with the brake pad 2. [Thermoelectric conversion element 4] The thermoelectric conversion element 4 has a structure in which two kinds of different semiconductors A and B are bonded via a metal plate. Has a power generation function that becomes a positive electrode and the semiconductor B becomes a negative electrode.

As the thermoelectric conversion element 4, for example, a germanium / silicon alloy element can be used. Also, this germanium / silicon alloy element
There is a loss due to heat conduction and the power generation efficiency is about 5%,
Higher efficiency can be obtained by using an alloy such as Ce, Fe, Co, Sb, or La developed in recent years.
Furthermore, alkali metal (beta alumina) is used (A
With MTEC (alkali metal thermoelectric conversion) power generation, the power of heat and current is improved, so that a power generation efficiency of about 30% can be obtained.

In the thermoelectric conversion element 4, the heat radiation side end of the heat pipe 3 is preferably connected to the heating side surface 4a. [The radiator 5] The radiator 5 is attached to the cooling side surface 4b of the thermoelectric conversion element 4, and is preferably an aluminum heat sink provided with a large number of cooling fins.

In the above-described configuration, when a brake is applied, the brake pad 2 is pressed against the rotating portion 1 and high heat is generated in the brake pad 2. This heat is instantaneously transmitted to the heating side surface 4 a of the thermoelectric conversion element 4 via the heat pipe 3.
On the other hand, since the cooling side surface 4b of the thermoelectric conversion element 4 is always cooled by the radiator 5, electric power is generated at the output terminal of the thermoelectric conversion element 4.

Thus, the frictional heat generated by the braking is efficiently converted into electric energy.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a regenerative braking device according to the present invention will be described in more detail with reference to the embodiment shown in FIG.

This regenerative braking device is applied to a disk brake for a vehicle, and a floating brake caliper 10 is mounted on a ventilated disk as a rotating unit 1.
(Brake device 20) is positioned so as to straddle it.
A piston 11 is provided in the brake caliper 10, and the brake pad 2 is pressed by the piston 11 and pressed by the rotating unit 1. A brake hose and other holding mechanisms are attached to the brake caliper 10, but their structure is the same as that of a general brake device, and a description thereof will be omitted.

One end (heat absorbing side) of the heat pipe 3 is attached to a position near the brake pad 2 of the brake caliper 10. In the case of the floating brake caliper system, the heat pipe 3 is connected to the brake caliper itself because one brake pad is integrated with the caliper. However, in the case of the fixed caliper system in which the rotor (rotating part) is floating. It is desirable that the heat pipe 3 be in contact with the brake pad 2 itself in order to efficiently transfer the heat generated in the brake pad 2.

The other end (radiation side end) of the heat pipe 3 is in close contact with the heating side surface 4 a of the thermoelectric conversion element 4. Silicon grease or the like is filled between the two in order to fill a small gap and increase the thermal coupling rate. The thermoelectric conversion element 4 is provided with a terminal for outputting the generated power, and is connected to the storage battery 6 via a voltage control circuit (regulator) 7. The thermoelectric conversion element 4 and the heat pipe 3 correspond to a thermoelectric conversion device 40.

When the thermoelectric conversion element 4 is not generating power, the voltage control circuit 7 electrically disconnects the thermoelectric conversion element 4 from the storage battery 6 to prevent leakage of current. Further, the voltage control circuit 7 suppresses the voltage when the output voltage of the thermoelectric conversion element 4 becomes equal to or higher than a specified value so that appropriate charging is performed. Note that the voltage can be controlled by connecting the emitter and the collector of a transistor in a charging circuit in series, and controlling the base voltage of the transistor to control the charging voltage. The output of the thermoelectric conversion element 4 is pulse width controlled (PWM) by a switching element.
However, there is a method of optimizing charging by controlling the duty ratio.

On the cooling side surface 4b of the thermoelectric conversion element 4,
A radiator (heat sink) 5 is attached via the heat pipe 3a. Since the radiator 5 needs to be constantly cooled, the radiator 5 is provided at a position through which the traveling wind passes, such as behind the radiator grill of the vehicle. Since the heat pipe 3a is provided to optimize the mounting position of the radiator 5, the cooling side surface 4b of the thermoelectric conversion element 4 is provided.
Needless to say, the radiator 5 may be directly attached to the radiator.

In the above-described configuration, when a brake is applied by depressing a brake pedal (not shown), the piston 11 advances and the brake pad 2 is pressed against the rotating portion 1. Then, high heat is generated due to friction between the brake pad 2 and the rotating part 1. This heat is instantaneously transmitted to the heating side surface 4 a of the thermoelectric conversion element 4 via the heat pipe 3.

On the other hand, since the cooling side surface 4b of the thermoelectric conversion element 4 is always cooled by the radiator 5 (via the heat pipe 3a), electric power is generated at the output terminal of the thermoelectric conversion element 4. This electric power charges the storage battery 6 via the voltage control circuit 7.

The electric power charged in the storage battery 6 can be used as electric power for traveling in a hybrid vehicle having an engine using an internal combustion engine and a motor for traveling. In a vehicle having only the engine as the drive system, the alternator has an effect of reducing the power generation load, and the fuel consumption can be suppressed.

As described above, conventionally, frictional heat generated by braking is wastefully released to the space, but in the regenerative braking device of the present embodiment, electric energy is efficiently obtained by the frictional heat.

Further, unlike a rotary generator, there is no inertia at the time of starting, so that the responsiveness is extremely excellent, and a shockless power generation is possible. In this embodiment, an example of application to a vehicle has been described. However, it is needless to say that the present invention can be applied to an industrial machine that operates substantially in the same manner as a vehicle.

[0030]

According to the brake regenerative device of the present invention, the heat generated by the brake device is converted into electricity using the thermoelectric conversion device to recover the kinetic energy of the vehicle. The structure is much simpler than that using a generator of the type, and the device can be reduced in size and weight, and the device can be manufactured at low cost. Further, since the structure is simple, retrofitting of the device to a ready-made vehicle can be easily performed.

Further, since the heat of the brake device can be efficiently radiated, it is possible to contribute to prevention of a vapor lock phenomenon and a fade phenomenon caused by overheating of the brake device.

In a vehicle using an internal combustion engine, the size of the generator can be reduced, and the power generation resistance can be reduced. Therefore, the traveling fuel can be reduced and the exhaust gas can be reduced.

Further, in the electric vehicle, the storage battery can be charged at the time of deceleration, so that it is possible to extend the traveling distance by one charge, and to reduce the size of the traveling storage battery.

Further, when the thermoelectric converter is provided with a heat pipe, the efficiency of heat conduction from the brake device to the thermoelectric converter is improved, so that the power generation efficiency can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a regenerative brake device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating part 2 Brake pad 3, 3a Heat pipe 4 Thermoelectric conversion element 4a Heating side 4b Cooling side 5 Radiator 6 Storage battery 10 Brake caliper 11 Piston 20 Brake device 40 Thermoelectric conversion device

Claims (2)

[Claims] 1. A brake device for braking a vehicle, a thermoelectric converter connected to the brake device and converting thermal energy into electric energy, and a storage battery connected to the thermoelectric converter. And regenerative braking device. 2. The thermoelectric conversion device includes: a heat pipe connected to a brake device; a thermoelectric conversion element connected to a heat radiation side end of the heat pipe; and a radiator connected to a cooling side surface of the thermoelectric conversion element. 2. The method according to claim 1, further comprising:
The regenerative braking device as described.