JPH0735846B2 - Exhaust energy recovery system for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust energy recovery system for an engine which is an internal combustion engine, and in particular, favorably controls an electric motor for power recovery and a speed switching device for power transmission. The invention also relates to a suitable one that is also used as an engine starter.

[Conventional technology]

Conventionally, as shown in Japanese Patent Laid-Open No. 57-59010, it has been considered to recover exhaust energy during engine operation.

In addition, a starter for starting the engine is still prepared even in a device provided with such an exhaust energy recovery system.

[Problems to be solved by the invention]

The above-mentioned prior art does not consider the combined use of the power recovery device and the starter, and 1) The conventional starter and its power source are required.

2) The installation space is large, and there are many difficulties, especially in the vehicle engine room where mounting density needs to be increased.

3) The starter is used only for a few seconds when the engine is started, and the rest is useless and heavy, which consumes unnecessary energy.

The object of the present invention is to solve these problems.

[Means for solving problems]

The above object is achieved by using the electric motor of the exhaust energy recovery system also as the starter.

That is, in the present invention, a ring gear attached to the output shaft of the engine, a rotation speed detector that detects the rotation speed of the output shaft of the engine, an AC generator that generates AC power by driving the turbine, and an engine During operation, a voltage control circuit for charging the battery with surplus power from the alternator,
It is installed between an AC electric motor driven by AC electric power and an output shaft of the AC electric motor and a ring gear of the engine, and switches the rotational force from the AC electric motor in two stages and transmits the switched rotational force to the ring gear. When the speed change power unit and the engine start switch are turned on, AC power is generated by the battery power to drive the AC electric motor, and the speed and torque of the AC electric motor are controlled based on the detection from the rotation speed detector. On the other hand, it has a control device for controlling the two-speed switching power unit. The second speed switching power unit is rotatably supported on the sun gear provided on the output shaft of the AC motor and on the output shaft of the AC motor, and has an internal gear formed on the inner circumference and the ring gear on the outer circumference. An output gear that forms an external gear that meshes with the first gear, a first planetary gear that meshes with the sun gear and revolves around the sun gear, and a first planetary gear that is coaxially attached to the first planetary gear. A pinion gear provided with a small number of gears, a second planetary gear that meshes with the pinion gear and the internal gear of the output gear, and the first and second planetary gears are provided around the sun gear between the sun gear and the output gear. By the planetary gear support that supports relatively revolving, and the control device, when the engine start switch is turned on, the output gear is disconnected from the output shaft of the AC motor, and when the engine is running,
A clutch mechanism that is controlled to connect the output gear to the output shaft of the AC motor, and a controller that stops the rotation of the planetary gear support when the engine start switch is turned on, and when the engine is running, the planetary gear support And a brake mechanism for releasing the.

[Action]

According to the present invention, as described above, the ring gear, the rotation speed detector, the AC generator, the voltage control circuit, the AC electric motor, the second speed switching power unit and the control unit are provided. By combining a sun gear, a planetary gear, a clutch machine, and a brake mechanism between the AC motor as an electric motor for the engine and the engine, the normal torque (small reduction ratio) of the electric motor can be applied at high speed during engine operation. When the engine is used at low speed and high torque at the time of starting the engine, the reduction ratio should be further increased so that a large torque can be produced.

That is, during operation, the rotation of the output shaft of the electric motor is transmitted as it is to the internal gear of the planetary gear mechanism by operating the clutch mechanism, and the power is transmitted to the ring gear of the engine by the gear provided on the outer periphery of the internal gear.

On the other hand, when the engine is started, the output shaft of the electric motor is transmitted to the internal gear via the planetary gear of the planetary gear mechanism by operating the brake mechanism to increase the reduction ratio, and similarly, a large torque of the ring gear can be transmitted.

Further, the clutch mechanism and the brake mechanism are interlocked so that they are in opposite operations so that the two can be safely switched.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 and 2 are views for explaining the internal structure of the two-speed switching power unit, and FIG. 3 is an example of an exhaust energy recovery system for an internal combustion engine of the present invention incorporating this two-speed switching power unit. FIG.

First, an example of an exhaust energy recovery system will be described with reference to FIG. Reference numeral 1 denotes an internal combustion engine (hereinafter simply referred to as an engine), an output shaft of which is connected with a ring gear 9 and a rotation speed detector 6, and an exhaust pipe is connected with a turbine 2 for recovering exhaust energy. . Reference numeral 3 is an AC generator connected to the turbine 2, and 4 is a control device including a variable frequency power supply device (hereinafter simply referred to as an inverter). The AC motor 5 is supplied with variable frequency AC power to control the speed of the AC motor 5. And torque control. Reference numeral 8 denotes a two-speed switching power unit in which one is connected to the AC motor 5 and the other is connected to the ring gear 9, and the rotational speed of the AC motor 5 is switched to two stages according to a command from the control unit 4 and transmitted to the engine 1. is there. Reference numeral 10 is a voltage control circuit that adjusts the charging / discharging voltage of the battery 11, and when the engine 1 is started, the battery is
The charging power of 11 is supplied to the control device 4, and when the engine 1 is operating, the battery 11 is charged with surplus power from the AC generator 3.

Now, in such a system, when the start switch 12 is turned on, the control device 4 uses the charging power of the battery 11 to generate AC power and starts the operation of the AC motor 5. At the same time, the control unit 4 switches the second speed switching power unit 8 so that the second speed switching power unit 8 operates at a large reduction ratio and acts as a starter of the engine 1. Therefore, the engine 1 is started by the action of the ignition device which will not be described in detail. When the operation of the engine 1 is started, the turbine 2 starts rotating due to the exhaust energy of the engine 2. Therefore, AC power is generated from the AC generator 3 by the exhaust energy.

Then, the control device 4 receives the AC power, and supplies the AC motor 5 with the AC power having an appropriate frequency so that the speed control of the AC motor 5 is performed according to the rotation speed detected by the rotation speed detector 6. . At the same time, the control device 4 issues a switching command for switching the second speed switching power unit 8 so that the reduction ratio of the second speed switching power unit 8 becomes small. Reference numeral 7 is an input detector for detecting an input current or input power to the AC motor 5,
Based on the detected value, various adjustments are performed to effectively use the output torque of the AC motor 5, that is, the recovered energy rather than the exhaust energy.

Next, the internal structure of the second speed switching power unit 8 will be described in detail with reference to FIGS. 1 and 2. First, 51 is the output shaft of the AC motor 5 attached to the fixed portion 21 not shown in detail,
A sun gear 52 is provided at the tip of this. 81 is the sun gear
It is a first planetary gear meshing with 52 and is supported by a rotating shaft 82 about a rotatable shaft l ₂ . Reference numeral 83 is a pinion gear that is connected to and attached to the first planetary gear 81, and the number of teeth of this pinion gear 83 is smaller than that of the first planetary gear 81. 84 is a second planetary gear that meshes with the pinion gear 83, and is rotatably supported by a rotating shaft 85 (centering on the shaft l ₃ ). 86a and 86b are a pair of planetary gear supports that support the ends of the rotary shafts 82 and 85, respectively, and the first and second planetary gears 81 and 8
The 4 is rotatably supported around the sun gear 52 (about the axis l ₁ ) while maintaining these relative relationships. That is, the inner diameter side (center part) of the disk-shaped planetary gear support 86a is supported by the rotating shaft 51 via a bearing.
Further, the planetary gear support 86b is configured in a disk shape with a center punched out or a simple disk shape. Reference numeral 90 denotes an output gear having a tubular shape with one end open and one end closed as a whole. An internal gear 91 provided on the inner wall side of the tubular surface of the output gear 91 meshes with the second planetary gear 84, and The external gear 92 provided on the outer wall side of the cylindrical surface meshes with the ring gear 9 of the engine 1. Further, the central portion of the wall surface 93 at one closed end of the output gear 90 is supported by the rotating shaft 51 via a bearing, and the output gear 90 rotates around the rotating shaft 51, that is, the first and second planetary gears 81.
It is rotatably supported around 84.

In this way, before and after the planetary gear mechanism C arranged at the shaft end of the rotary shaft 51, a clutch mechanism for further connecting / disconnecting the rotation of the output shaft 51 to the output gear 90 having the internal gear 91 or the like. B, a brake mechanism D for stopping the rotation of the planetary gear supports 86a, 86b of the planetary gear mechanism C is provided. First, the clutch mechanism B has a stator 100 having an exciting coil for an electromagnet attached to the fixed portion 21, a stator non-magnetic member portion facing the stator 100 (the other portion is made of a magnetic material). The friction plate 101 having the central portion fixed to the output shaft 51, and further, the movable plate 10 provided so as to be movable back and forth with respect to the wall surface 93 of the output gear 90 via the guide bolt 103 and being prevented from rotating.
2. Although not shown, it is composed of a spring member or the like for separating the movable plate 102 from the friction plate 101 when the exciting coil is not excited. Next, the brake mechanism D (which is essentially the same as the clutch mechanism) has a stator 121 having an exciting coil for an electromagnet attached to the fixed portion 22, and faces the stator 121.
The movable plate 122 is provided so as not to rotate with respect to 22 and to be movable back and forth on the side of the stator 121, the brake plate 123 having a brake lining that moves forward and backward together with the movable plate 122, and although not shown, the movable plate 122 is used when the exciting coil is not excited. Is pressed against the planetary gear support 86b via the brake plate 123 to stop the rotation of the planetary gear support 86b.

Further, referring to FIG. 2, a plurality of sets (two sets in the embodiment) of pinion gears 83 connecting the first and second planetary gears 81 and 84 are provided, and the internal gear 91 of the output gear 90 is provided.
It is arranged inside and on the planetary gear supports 86a and 86b. Note that FIG. 1 shows a cross section taken along the line AA in FIG.

Now, next, the two-speed switching power unit 8 configured as described above
The speed switching operation will be described. First, for example, when the starting switch 12 is turned on, the control device 4 stops the energization of the exciting coils of the stators 100 and 121 of the clutch mechanism B and the brake mechanism D of the second speed switching power unit 8, and at the same time, the power of the battery 11 is reduced. Then, the operation of the AC motor 5 is started.
Since the energization of both exciting coils is released, the friction plate 101 and the movable plate 102 are separated from each other in the clutch mechanism B, and the rotation of the rotary shaft 51 is not directly transmitted to the output gear 90. On the other hand, in the brake mechanism D, since the movable plate 122 is released, the movable plate 122 presses the brake plate 123 toward the planetary gear support 86b side and restrains its rotation. Therefore, the rotation of the rotating shaft 51 is the same as the sun gear 52 → the first planetary gear 81.
-> Pinion gear 83-> 2nd planetary gear 84-> Internal gear 91 It is transmitted to the output gear 90 after being greatly reduced, and then rotated. Of course, the rotation direction of the output gear 90 at this time coincides with the rotation direction of the rotating shaft 51 (sun gear 52), and the rotation of the output gear 90 is transmitted to the engine 1 via the ring gear 9.

Now, in order to start the engine 1 and start collecting exhaust energy, the control device 4 energizes the exciting coils of the clutch mechanism B and the brake mechanism D, and the clutch mechanism B causes the movable plate 102 to move.
To the friction plate 101, and in the brake mechanism D, the movable plate 122 is pulled back to open the planetary gear support 86b. As a result, the rotary shaft 51 → the friction plate 101 → the movable plate 102 → the guide bolt 10
3 → Connected to the output gear 90, the rotation of the rotary shaft 51 is directly transmitted to the output gear 90. The planet gear 8
1,84 will revolve around the sun gear 52.

In the embodiment, the clutch mechanism B is shown to be disconnected when the exciting coil is not energized. However, it is of course possible to use a clutch mechanism B having a reverse operation. As for the above, it is also possible to adopt a configuration in which the brake works when the exciting coil is energized.

According to the above embodiment, the starter (motor) required for starting the engine 1 and the AC motor 5 required for recovering the exhaust energy are shared by the second speed switching power unit 8. As a result, it is possible to obtain the following effects.

1) The system price becomes cheap.

2) Devices can be compactly packed, and the space usage space increases.

Especially in automobiles and the like, it is extremely difficult to secure a space for use, which is particularly effective.

3) Since the conventional starter is a DC motor in particular, it easily breaks down and requires maintenance of brushes and the like, but in the present system using an AC motor, this need is eliminated.

4) The mechanism is simplified, and the pinion gear is prevented from being caught at the time of starting as in the conventional starter, and the reliability is greatly improved.

5) By using a two-stage planetary gear that meshes with the sun gear and the internal gear separately, it is possible to rotate the internal gear in the same direction as the sun gear with a larger reduction ratio. Could be simplified.

6) It is not necessary to switch the combination of gears at the time of gear shifting operation, and synchronization at the time of switching is also unnecessary, and it is possible to easily switch even at high speed rotation.

〔The invention's effect〕

As described above, the present invention has the ring gear, the rotation speed detector, the AC generator, the voltage control circuit, the AC motor, the second speed switching power unit and the control unit, and the second speed switching power unit is a solar It has a gear, an output gear, a first planetary gear, a pinion gear, a second planetary gear, a planetary gear support, a clutch mechanism, and a brake mechanism. When the engine start switch is turned on, the AC motor is driven by the controller. In addition, the clutch mechanism is disengaged, the brake mechanism is activated to stop the planetary gear support from rotating, and the rotation of the output shaft of the AC motor causes the ring gear to move through the sun gear, the first and second planetary gears, and the output gear. Since the engine is started by rotating the engine, it is inexpensive and compact, and there is an effect that maintenance is unnecessary.

[Brief description of drawings]

FIG. 1 is a sectional view of a two-speed switching power unit applied to an exhaust energy recovery system for an internal combustion engine of the present invention, FIG. 2 is a schematic diagram for explaining the operation of a planetary gear mechanism of the two-speed switching power unit, and a third diagram. FIG. 1 is a block diagram showing an example of an exhaust energy recovery system for an internal combustion engine of the present invention. 1 ... Engine, 2 ... Turbine, 3 ... Alternator,
4 ... Control device, 5 ... AC motor, 6 ... Rotation speed detector, 7 ... Input detector, 8 ... Second speed switching power unit,
9 ... Ring gear, 10 ... Voltage control circuit, 11 ... Battery, 51 ... Rotating shaft, 52 ... Sun gear, 81 ... First planetary gear, 83 ... Pinion gear, 84 ... Second Planetary gears, 86
a, 86b ... Planetary gear support, 91 ... Internal gear, B ... Clutch mechanism, C ... Planetary gear mechanism, D ... Brake mechanism.

Claims (1)

[Claims] 1. In an exhaust energy recovery system for an internal combustion engine that drives a turbine by utilizing exhaust energy of an engine, a ring gear mounted on an output shaft of the engine and a rotational speed for detecting the rotational speed of the output shaft of the engine. A detector, an AC generator that generates AC power by driving a turbine, a voltage control circuit that charges a battery with surplus power from the AC generator when the engine is operating, an AC motor that is driven by an AC voltage, and A two-speed switching power unit that is installed between the output shaft of the AC motor and the ring gear of the engine, switches the rotational force from the AC motor in two stages, and transmits the switched rotational force to the ring gear, and an engine start switch. When the power is turned on, the AC power is generated by the battery power to drive the AC motor and the While controlling the speed and torque of the AC motor based on the output, and a control device for controlling a two-speed switching power unit, the two-speed switching power unit,
A sun gear provided on the output shaft of the AC motor, and an output that is rotatably supported on the output shaft of the AC motor and that has an internal gear formed on the inner circumference and an external gear that meshes with the ring gear on the outer circumference. A gear, a first planetary gear that meshes with the sun gear and revolves around the sun gear, and a pinion gear that is coaxially attached to the first planetary gear and that has a smaller number of teeth than the first planetary gear. A second planetary gear meshing with the pinion gear and the internal gear of the output gear, and the first and second planetary gears are supported between the sun gear and the output gear so as to be relatively revolvable around the sun gear. The planetary gear support and the control device control the output gear to be disconnected from the output shaft of the AC motor when the engine start switch is turned on, and to connect the output gear to the output shaft of the AC motor when the engine is running. The internal combustion engine is characterized in that it has a clutch mechanism and a brake mechanism for stopping the rotation of the planetary gear support when the engine start switch is turned on by the control device and for opening the planetary gear support during engine operation. Exhaust energy recovery system for engines.