JP2001234836A - Always engaged type starter mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an always engaged type starter mechanism capable of reducing rolling vibration of an engine. SOLUTION: A crankshaft 14 of the engine 2 and a rotor shaft (a rotary shaft) 2 of a motor generator 3 (an electric motor) are connected to each other so as to rotationally drive by a plurality of intermediate gears (intermediate rotary shafts) 18, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter mechanism for transmitting a rotational driving force to a crankshaft of an internal combustion engine and starting the engine. In particular, a starter mechanism is connected between the crankshaft and the electric motor so that the rotational driving force can be mutually transmitted and received. The present invention also relates to a constant-mesh type starter mechanism that can drive an electric motor as a generator when the engine is driven.

[0002]

2. Description of the Related Art Conventionally, in many hybrid cars using an internal combustion engine and an electric motor (for example, a motor generator) in combination, a medium-low load region where engine efficiency is low is driven only by an electric motor or the like. For this reason, it is necessary to increase the size of the electric motor and the like and to use a large-capacity battery, thereby increasing the weight, increasing the size of the packaging covering the drive system, and inevitably affecting the mountability. Therefore, there is a simple hybrid system in which the engine is constantly operated and the engine is assisted by the torque generated by the motor when a large load is applied to the engine during acceleration or the like, and the motor is driven as a generator during deceleration to regenerate energy. Conceivable. An example of an engine used in a conventional hybrid system is proposed in Japanese Patent Application No. 2000-24999 filed by the present applicant, and discloses an engine having a layout as shown in FIG.

Here, in the engine 100 shown in FIG.
In order for the electric motor to function as a starter, the reduction ratio between the starter (electric motor) 120 and the ring gear 140 on the crankshaft 110 is set to be somewhat large.
Further, an intermediate gear 150 is provided between the ring gear 140 and the starter 120 to secure a distance L between the shafts from the viewpoint of securing mounting space and layout. In this way, by connecting the starter (electric motor) 120 and the crankshaft 110 with a constant meshing gear train, the electric motor 120 is driven as a starter at the time of engine start, and the motor 120 is driven when the output becomes insufficient at the time of the subsequent engine drive. When the engine is assisted, the motor 120 can be driven as a generator during deceleration.

By the way, in order to ensure quietness of a vehicle,
It is necessary to reduce vehicle body vibration. Particularly, in a hybrid vehicle, the occupant is more likely to feel uncomfortable due to vibration when the engine is driven. Therefore, it is known to use a torque balancer to further reduce rolling vibration around the crankshaft during engine operation.

[0005]

By the way, the electric motor 120 provided in the engine 100 shown in FIG. 4 can be regarded as a relatively large inertial mass, and it can be considered that the electric motor 120 functions as a torque balancer for reducing rolling vibration. .
However, in the engine 100 shown in FIG. 4, when the piston 160 receives the pressing force P due to the combustion gas pressure, the rotation driving force Na acts on the crankshaft 110 in the rotation direction q, and the explosion reaction force acts on the engine body 101. The rolling moment Ma due to -P1 acts. On the other hand, the motor 120
The rotational driving force Na is transmitted in the rotational direction q to the rotor shaft 121, which is the rotational mass of the rotor shaft 121, via the crankshaft 110 and the intermediate gear 150, whereby the rotor shaft 121 has a rolling moment Mb (=
Na × L). However, the rolling moment Mb coincides with the direction of the rolling moment Ma due to the explosion reaction force -P1, which amplifies the vehicle body vibration, does not function as a torque balancer, and has been desired to be improved.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a constant-mesh starter mechanism that enables an electric motor connected to a crankshaft to function as a torque balancer and reduces rolling vibration of the engine. The purpose is to:

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is such that a crankshaft of an engine and a rotating shaft of an electric motor can be driven to rotate relative to each other by an even number of intermediate rotating shafts. Connected. Since an even number of intermediate rotation shafts are used, the rotation direction of the crankshaft and the rotation direction of the electric motor are opposite. For this reason, when a rotational driving force is applied to the rotating shaft of the electric motor from the crankshaft via the intermediate rotating shaft when the engine is driven after the electric motor functions as a starter, this generates a moment around the crankshaft, and this moment is generated by the moment of the engine. The rolling moment due to the reaction force of the explosion is canceled, and the body vibration can be reduced. Further, because of the constant meshing type, the driving force can be assisted by the electric motor during traveling, and the traveling performance is improved. Also, since it is a constant mesh type, after the electric motor functions as a starter and starts the engine, it is driven from the engine side and can be used as a generator.

According to a second aspect of the present invention, in the constant mesh starter mechanism according to the first aspect, the inertial mass member fixedly disposed on the crankshaft and the outer peripheral side of the inertial mass member are disposed. A drive gear disposed on a rotating shaft of the electric motor, the driving gear being connected to the ring gear via an intermediate gear disposed on the intermediate rotating shaft so as to transmit a rotational driving force. Thus, since there is an intermediate gear between the rotating shaft of the electric motor and the crankshaft,
Since the degree of freedom is provided in the diameter of the drive gear on the motor side and the total reduction ratio can be increased to some extent, the startability is not impaired.
In addition, it is easy to reduce the number of revolutions of the electric motor after the start, and the durability of the electric motor can be improved. Further, the radius of the ring gear can be reduced by interposing the intermediate gear, and the engine can be reduced in weight. The inertial mass member may be a flywheel, a starting clutch, a torque converter, or the like. In this case, in particular,
Conventional equipment can be used, and implementation can be facilitated.

[0009]

1 to 3 show a drive system 1 of a hybrid vehicle equipped with a constant mesh starter mechanism to which the present invention is applied. The drive system 1 of the hybrid vehicle includes an engine 2 and a motor generator 3 as a vehicle drive force source in parallel, and controls them based on an engine drive priority mode by a control circuit 4 to control each drive force on the drive wheel W side. To be communicated to.

The drive system 1 includes a damper 5, a forward / reverse switching planetary gear train 6, a transmission 7, a starting clutch 8, a reduction gear 9,
The differentials 10 are connected in this order, and the output of the differential 10 is transmitted to the drive wheels W. The driven-side members of the drive system 1 are housed in a casing 32 which is fastened and fixed to the rear gear cover 22 described later.

The engine 2 may be a well-known four-cycle gasoline engine, and it is desirable to employ a direct injection gasoline engine capable of reducing exhaust gas emission and achieving low fuel consumption. The engine 2 includes a plurality of cylinders 11 (only one is shown in FIG. 1) in a main body 201. Each cylinder 1
The piston 12 in 1 receives a combustion gas pressure in a combustion chamber (not shown) to generate a pressing force P, which is transmitted to a pin 141 of a crankshaft 14 via a connecting rod 13 and converted into a rotational driving force of the crankshaft 14. ing.

One end of the crankshaft 14 has a body 201.
A ring gear 15 having a disk portion 151 as an inertia mass member and a flywheel 16 are successively overlapped with each other to form a protruding end portion 142, and are connected by tightening with a plurality of bolts (not shown). An electric motor driving gear train 17 is connected to the ring gear 15 in a constant meshing state. The motor drive gear train 17 is a first gear meshing with the ring gear 15.
An intermediate gear 18, a second intermediate gear 19 meshing with the first intermediate gear 18, and a drive gear 20 of the motor generator 3 meshing with the second intermediate gear 19;
1, 22. The front and rear gear covers 21,
The rotation shaft portions 181 and 191 of the first and second intermediate gears 18 and 19 are pivotally mounted on the rotation shaft 22. Here, the motor drive gear train 17 is provided with an even number of two intermediate gears 18 and 19 between the crankshaft 14 and the rotor shaft 26 integrated with the drive gear 20, thereby reversing the rotation direction n of both. In addition, the center distance L (see FIG. 3) is ensured.

In setting the gear ratio of the motor drive gear train 17, the following points are considered. That is, when the motor generator 3 functions as a starter, it is necessary to secure a certain large total reduction ratio with the ring gear 15, and conversely, when the motor generator 3 functions as a generator, It is necessary to prevent excessive rotation of the motor generator 3 when the engine is driven, and to suppress the gear ratio to a level that can improve the durability of the electric motor. Gear 1
5 and the gear ratio of the drive gear 20 are set. The radius of the ring gear 15 can be made relatively small by the interposition of the two intermediate gears 18 and 19, and it is easy to reduce the weight of the engine.

A plurality of portions of the front gear cover 21 are fixed to the engine body 201 side by bolting, and the front gear cover 21 and the rear gear cover 22 are bolted to each other at their peripheral edges. The front gear cover 21 protrudes laterally (upward in FIG. 2) of the main body 201 and has a motor generator 3
Are integrally tightened and connected. Outer part 2
A stator 25 connected to an inverter 24 to be described later is accommodated inside 3, and a rotor shaft 26 is accommodated inside thereof. The drive gear 20 at the tip of the rotor shaft 26 is housed in front and rear gear covers 21 and 22.

When a predetermined alternating current is supplied to the coil in the stator 25, the motor generator 3 forms a rotating magnetic field to induce an induced current in the stator 25, and an interaction between the induced current and the rotating magnetic field causes the rotor shaft to rotate. A configuration is adopted in which the motor functions as a well-known motor that generates a driving torque on the 26 side, and also functions as a generator when operating as a driven side. The inverter 24 is driven according to a command signal from the control circuit 4, and when the motor generator 3 functions as a generator, converts the AC power from the motor generator 3 into DC and supplies it to the battery 27. When the motor generator 3 functions as an electric motor (starter), the DC current of the battery 27 is converted into predetermined AC power and supplied to the motor generator 3. Rear gear cover 2
The damper 5 protruding from the second drive shaft 28 includes a flywheel 16 directly connected to the crankshaft 14 and a first drive shaft 28.
A well-known structure is adopted in which the relative rotational displacement between and is absorbed by an elastic body. The planetary gear train 6 for switching between forward and backward movement includes the first drive shaft 2.
8 and a second drive shaft 29, a friction engagement member (not shown) which is operated to switch the hydraulic pressure in response to a command from the control circuit 4, and switches the drive mode of the rotating element of the planetary gear train by the switching. And a well-known mechanism for rotating the second drive shaft 29 forward or reverse with respect to the first drive shaft 28.

The transmission 7 is a belt-driven continuously variable transmission (not shown) and includes a hydraulic actuator (not shown) that operates to switch the hydraulic pressure in response to a command from the control circuit 4, thereby winding the belt between a pair of pulleys. A known configuration is adopted in which the gear ratio is changed by switching the hanging diameter. The output of the transmission 7 is transmitted to the speed reducer 9 via the starting clutch 8 that connects the third drive shaft 30 and the fourth drive shaft 31 in an intermittent manner. The starting clutch 8 includes a hydraulic actuator (not shown) that operates to switch the hydraulic pressure in response to a command from the control circuit 4.
Is transmitted to the speed reducer 9 in a desired connection mode. Further, the rotational driving force of the speed reducer 9 is the differential 1
0 can be transmitted to the left and right drive wheels W.

The operation of the drive system 1 of the vehicle, which is equipped with the always-meshing type starter mechanism and forms a simple hybrid system, will be described below. When the engine is started, the control circuit 4 switches the starting clutch 8 to the disengaged state, and switches and controls the inverter 24 to the start mode. This allows the inverter 24
Converts the DC current of the battery 27 into predetermined AC power and supplies it to the motor generator 3,
Is driven as a starter, and its rotational force is transmitted to the crankshaft 14 via the motor drive gear train 17. At this time, the rotational force of the motor generator 3 as a starter is reduced at a reduction ratio corresponding to the gear ratio between the drive gear 20 and the ring gear 15, and the engine 2 is started with a sufficient start torque.

After starting the engine, the control circuit 4 drives the engine in a predetermined operation mode based on operation information such as the gear ratio of the transmission 7, the accelerator opening, the vehicle speed, etc., and engages the starting clutch 8 in the predetermined starting mode. Let it start, then go on the run.

The control circuit 4 of the engine 2 which forms a simple hybrid system drives the motor generator 3 during traveling based on the engine drive priority mode. That is,
When the control circuit 4 determines that the current operation range is in the acceleration range based on the current accelerator opening, the control circuit 4 switches the inverter 24 to the motor operation mode, converts the current of the battery 27 into AC power, and supplies the AC power to the motor generator 3. As an electric motor, and an engine assist operation for further reinforcing the engine output with the rotational driving force is performed. Conversely, when it is determined that the current operation area is in the deceleration area, the inverter 24 is switched to the generator operation mode, and the AC power from the motor generator 3 is converted into DC and supplied to the battery 27 to regenerate energy.

As described above, the engine 2 used in the simple hybrid system is driven in the engine drive priority mode in most of the operating range. As shown in FIG. 3, in this engine driving state, a pressing force P due to the combustion gas pressure generated in each cylinder generates a rotational driving force N1 in the rotational direction n on the crankshaft 14 via the piston 12; An explosion reaction force -P is generated in the engine body 201, and a rolling moment M1 in the reverse rotation direction -n due to the explosion reaction force acts. In addition, the ring gear 15 on the crankshaft 14 causes the first intermediate gear 18 to apply a rotational driving force N1 in the reverse rotation direction -n. The rotational driving force N1 received by the first intermediate gear 18 acts on the second intermediate gear 19 in the rotation direction n, and the rotational driving force N1 received by the second intermediate gear 19 is
In the reverse rotation direction -n. At this time, the rotational driving force N1 received by the drive gear 20 and the rotor shaft 26 acts upward, and this is a rolling moment M2 (= L × N1) around the crankshaft 14 with respect to the engine body 201.
Is caused.

As described above, the rolling moment M around the crankshaft 14 generated by the rotational driving force N1 applied to the motor generator 3 from the crankshaft 14
2 acts in a direction to cancel the rolling moment M1 around the crankshaft 14 due to the explosion reaction force -P. That is, the two intermediate gears 18 and 19 are attached to the crankshaft 14.
Is connected to the motor generator 3 through the rotation direction n of the crankshaft 14 and the motor generator 3
The rotation direction −n of the rotor shaft 26 is opposite, and the starter mechanism having the motor generator 3 of FIG. 1 can also function as a torque balancer. In particular, here, since the constant-mesh type starter mechanism is mounted on the hybrid vehicle, it is possible to sufficiently satisfy the demand for lowering the vibration of the hybrid vehicle, in which the occupants are likely to feel uncomfortable due to the vibration when the engine is driven.

Therefore, when the engine is started, the motor generator 3 and the motor drive gear train 17 can start the engine as a starter. After the engine is driven, the motor generator 3 and the motor drive gear train 17 are driven by the rolling moment due to the explosion reaction force of the engine. By canceling M1, the rolling vibration and the vehicle body vibration, which are the main vibrating forces of the engine, can be reduced. Further, since the crankshaft 14 and the motor generator 3 are always meshed, engine assist can be performed by the motor generator (motor) 3 during traveling,
Drivability is improved. In addition, since the crankshaft 14 and the motor generator 3 are always meshed, the engine 2 can be driven in a predetermined power generation mode during deceleration or when the charged voltage of the battery 27 is lower than the required charging voltage.
At this time, the motor generator 3 can be used as a generator,
Even in these cases, the motor generator 3 and the motor drive gear train 17 cancel the rolling moment M1 due to the reaction force of the explosion of the engine, and the rolling vibration and the vehicle body vibration, which are the main vibrating forces of the engine, can be reduced.

In the above-mentioned process, the gear train 17 for driving the electric motor of the engine 2 uses the two intermediate gears 18 and 19 to connect the crankshaft 14 and the motor generator 3 so as to be rotatable. The crankshaft and the motor generator may be rotatably connected using four intermediate gears. Also in this case, the rotation directions of the crankshaft and the motor generator are opposite, the starter mechanism can also function as a torque balancer, and the rolling vibration of the engine and the vehicle body vibration can be reduced.

Further, in the engine 2 of FIG. 1, the ring gear 15 having the disk portion 151 as the inertia mass member and the motor generator 3 are rotatably connected by using the motor drive gear train 17. Accordingly, only the flywheel directly connected to the crankshaft may be provided as the inertial mass member, and a ring gear connected to the gear train for driving the electric motor may be formed on the outer peripheral portion. Furthermore,
As an inertia mass member, a torque converter or a starting clutch (not shown) directly connected to the crankshaft 14 may be used, and a ring gear connectable to a gear train for driving an electric motor may be formed on the outer peripheral side thereof. The same operation and effect as those of the constant mesh starter mechanism provided in the drive system 1 of the hybrid vehicle can be obtained.

Although the rotor shaft 26 of the motor generator 3 has been described as the rotating shaft of the electric motor, a motor and a generator (not shown) may be directly connected by a rotating shaft, and this rotating shaft may be connected to the crankshaft side by a gear train for driving the motor. In this case, the same operation and effect as those of the constant-mesh starter mechanism provided in the drive system 1 of the hybrid vehicle in FIG. 1 can be obtained.

[0026]

According to the first aspect of the present invention, since an even number of intermediate rotating shafts are used, when the engine is driven after the motor has functioned as a starter, the rotation of the electric motor from the crankshaft via the intermediate rotating shaft is performed. When a rotational driving force is applied to the shaft, this generates a moment around the crankshaft,
This moment cancels the rolling moment due to the reaction force of the engine explosion, and the vibration of the vehicle body can be reduced. Furthermore,
Because of the constant meshing type, the driving force can be assisted by the electric motor during traveling, and the traveling performance is improved. Also, since it is a constant mesh type, after the electric motor functions as a starter and starts the engine, it is driven from the engine side and can be used as a generator.

According to the second aspect of the present invention, since the intermediate gear is provided between the rotating shaft of the electric motor and the crankshaft, the degree of freedom can be given to the driving gear diameter on the electric motor side and the total reduction ratio can be increased to some extent. The starting performance is not impaired. In addition, it is easy to reduce the number of revolutions of the electric motor after the start, and the durability of the electric motor can be improved. Further, the radius of the ring gear can be reduced by interposing the intermediate gear, and the engine can be reduced in weight.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view of an engine to which a constant mesh starter mechanism according to an embodiment of the present invention is applied.

FIG. 2 is a schematic plan sectional view of the engine of FIG. 1 and a driving system connected to the engine.

FIG. 3 is an explanatory diagram of vibration characteristics of the engine of FIG. 1;

FIG. 4 is an explanatory diagram of vibration characteristics of a conventional engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive system 2 Engine 3 Motor generator 14 Crankshaft 15 Ring gear 151 Disk part 16 Flywheel 17 Gear train for motor drive 18, 19 Intermediate gear (intermediate rotating shaft) 26 Rotor shaft (rotating shaft)

Claims (2)

[Claims] 1. A constantly meshing starter mechanism wherein an engine crankshaft and a rotating shaft of an electric motor are connected to each other by an even number of intermediate rotating shafts so as to be rotatable with each other. 2. The starter mechanism according to claim 1, further comprising: an inertia mass member fixedly disposed on said crankshaft; and a ring gear disposed on an outer peripheral side of said inertia mass member. A driving gear disposed on a rotating shaft of the electric motor is connected to the ring gear via an intermediate gear disposed on the intermediate rotating shaft so as to transmit a rotational driving force.