JP6012392B2 - Hybrid system - Google Patents

Description

The present invention relates to a parallel hybrid system for transmitting the driving force of the engine and the motor generator to a continuously variable transmission mechanism.

As a hybrid system that can be mounted on a work machine capable of traveling such as a tractor, a backhoe, a multi-purpose work vehicle, and a passenger car, and transmits a driving force of an engine and a motor generator to a belt type continuously variable transmission mechanism (CVT), Patent Literature There are those disclosed in 1 and 2.
In the technique of Patent Document 1, an engine crankshaft is connected to an input member of a multi-plate clutch, and an output member of the clutch is connected to a drive shaft of a belt-type continuously variable transmission mechanism. An electric motor having a rotor attached to the side so as to be integrally rotatable, an ordinary mode driven by the engine, an assist mode driven by the engine and the electric motor, an EV mode driven by the electric motor, and a regenerative mode for regeneratively braking the electric motor, It has.

  In Patent Document 2, the crankshaft of the engine is connected to an input member of a multi-plate clutch, the output member of the clutch is connected to one end of a drive shaft of a belt type continuously variable transmission mechanism, and the other end of the drive shaft is connected. It is connected to an electric motor.

JP 2010-261544 A JP 2003-307270 A

  In the technique of Patent Document 1, in order to operate the electric motor to enter the hybrid function, the clutch must be engaged using a manual device or an electric control device, and the EV mode is driven by the electric motor. When the regenerative mode is used for regenerative braking of the electric motor, the clutch is engaged so that the engine crankshaft also rotates, making it difficult to enter the EV mode or the regenerative mode without rotating the crankshaft. It has become.

In the technique of Patent Document 2, even when the clutch is disengaged, the output shaft of the electric motor can be driven directly to the drive shaft of the continuously variable transmission mechanism or via the gear transmission means. A space must be provided outside the axial center direction or radially outward direction of the drive shaft of the step transmission mechanism, and the apparatus becomes large.
An object of the present invention is to provide a hybrid system that can solve such problems of the prior art.

  The present invention can provide a hybrid function by a motor generator regardless of the disengagement state of the clutch regardless of whether the engine crankshaft is stopped or rotating at a low speed, and is compact between the clutch and the continuously variable transmission mechanism. An object of the present invention is to provide a hybrid system that can be configured as follows.

Specific means for solving the problems in the present invention are as follows.
First, an oil pump 20 that can support the crankshaft 3 protruding from the engine E is provided, and a one-way automatic transmission type clutch 4 is connected to the oil pump 20 and extends from the oil pump 20 to the clutch 4. The provided crankshaft 30 is connected to the input member 4A of the clutch 4, the output member 4B of the clutch 4 is connected to the drive shaft 6 of the continuously variable transmission mechanism 5, and the drive member 7 of the continuously variable transmission mechanism 5 and the clutch The rotor 9 of the motor generator 8 is connected on the drive shaft 6 between the four output members 4B.

Secondly, the output member 4B of the clutch 4 and the drive shaft 6 of the continuously variable transmission mechanism 5 are integrally connected concentrically, and the rotor 9 is fitted and fixed to the drive shaft 6, so that the motor case of the motor generator 8 is obtained. 8 a is fixed to the clutch casing 4 a of the clutch 4 and the transmission case 19 of the continuously variable transmission mechanism 5.
Thirdly, the continuously variable transmission mechanism 5 is a belt-type continuously variable transmission mechanism, and the clutch 4 is a centrifugal clutch or a one-way clutch.

Fourth, when the engine E is stopped, the engine E rotates at a low speed at which the engine E rotates at a speed at which the power transmission through the clutch 4 is interrupted or at a speed at which the power is transmitted through the clutch 4. The motor generator 8 is provided with a control means 11 that drives the rotor 9 during motor rotation.
Fifth, the motor E is provided with control means 11 for causing the motor generator 8 to drive the rotor 9 with the power from the engine E when the engine E rotates at high speed.
Sixth, the motor E is provided with a control means 11 for driving the rotor 9 with the power from the continuously variable transmission mechanism 5 when the rotational speed of the engine E is reduced.

According to the present invention, the hybrid function of the motor generator can be exhibited regardless of whether the clutch is disengaged regardless of whether the engine crankshaft is stopped or rotating at a low speed, and between the clutch and the continuously variable transmission mechanism. Can be configured compactly.
That is , because the rotor 9 of the motor generator 8 is connected to the drive shaft 6 between the drive member 7 of the continuously variable transmission mechanism 5 and the output member 4B of the clutch 4, the crankshaft 3 of the engine E is stopped. Even if the motor generator 8 rotates at a low speed, the motor generator 8 can be driven in both the driving mode and the regenerative mode, and the motor generator 8 can be compactly arranged both in the axial direction and in the radially outward direction of the drive shaft 6. .

Further , since the rotor 9 is fitted and fixed to the drive shaft 6 and the motor case 8 a is fixed to the clutch casing 4 a and the transmission case 19, the motor generator 8 is compact between the clutch 4 and the continuously variable transmission mechanism 5. Can be arranged.
Further , the driving force or braking force of the motor generator 8 is transmitted to the belt-type continuously variable transmission mechanism while automatically transmitting the driving force of the engine E to the belt-type continuously variable transmission mechanism via the centrifugal clutch or the one-way clutch. Can do.

Further , the motor generator 8 can be caused to function as a motor when the engine E is stopped, at a low speed or at a high speed.
In addition , when the engine E rotates at a high speed, the motor generator 8 can have a generator function to generate power.
Further , when the rotational speed of the engine E is decreased, the motor generator 8 can be caused to perform a generator function to regenerate and brake energy.

It is a whole section front view showing an embodiment of the invention. FIG. It is an expanded sectional front view of the principal part. It is sectional drawing of a motor generator. It is a graph which shows the torque power relationship of a hybrid system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1-4, the hybrid system 1 applicable as a drive part mounted in the lower part of the loading platform of a four-wheel drive work vehicle is illustrated.
The hybrid system 1 is a power transmission device that transmits the power of the engine E and the motor generator 8 to the transmission M via the continuously variable transmission mechanism 5.

The body 20a of the oil pump 20 and the clutch casing 4a of the clutch 4 are connected to the side surface of the engine E protruding the crankshaft 3, and the motor case 8a of the motor generator 8 is fixed to the clutch casing 4a. Further, the input side of the transmission case 19 of the continuously variable transmission mechanism 5 is fixed.
The engine E is an OHC type single-cylinder air-cooled engine, and its crankshaft 3 extends through the oil pump 20 into the clutch casing 4a of the clutch 4, and the input member 4A of the clutch 4 is fitted. The output member 4B is rotatably supported.

The body 20 a of the oil pump 20 constitutes a partition wall that partitions the engine E and the clutch 4, and also serves as a bearing case that supports the crankshaft 3.
The clutch 4 is a one-way automatic transmission type clutch that transmits the rotational power of the crankshaft 3 in one direction to automatic transmission, but does not transmit power from the opposite direction. For example, the crankshaft 3 has a predetermined rotational speed or more. A one-way clutch (free wheel) that always transmits the rotation of the crankshaft 3 but is free in the reverse direction can be employed.

In the embodiment, a centrifugal wet clutch is employed for the clutch 4, and the rotational driving force of the crankshaft 3 is transmitted to the downstream side based on the centrifugal force that increases according to the rotational speed of the crankshaft 3.
The clutch 4 includes an input member 4A and an output member 4B disposed in a clutch chamber surrounded by a clutch casing 4a. The input member 4A is fitted and fixed to the crankshaft 3 so that a plurality of clutch plates 21 can swing. The output member 4B has a cup shape that covers the clutch plate 21 and is supported at the end of the crankshaft 3 through a bearing 22 so as to be relatively rotatable, and at the same time, is rotated by the clutch casing 4a through the bearing 23. It is supported freely.

The clutch 4 drives the input member 4A with the crankshaft 3, and the clutch plate 21 is swung by the centrifugal force by the rotation of the input member 4A and comes into contact with the output member 4B. Is transmitted.
The output member 4B is formed integrally with the drive shaft 6 of the continuously variable transmission mechanism 5. The drive shaft 6 has a rotor shaft portion 6A at the end on the clutch 4 side, and this rotor shaft portion 6A is connected to the output member 4B. The output member 4B, the rotor shaft portion 6A, and the drive shaft 6 have an axial center. It is concentric with the axis of the crankshaft 3.

The rotor shaft portion 6A can be formed separately from the output member 4B and / or the drive shaft 6 and can be fitted and connected by a spline or the like. However, it is advantageous to integrally form by forging or the like in terms of strength and cost. become.
The clutch casing 4a of the clutch 4 has an inner case portion 4aA that is concentric with the output member 4B and covers the outside of the diameter thereof, and an outer case portion 4aB that covers the outside of the outer casing portion 4aA. It is common to some parts and is connected on the body 20a side of the oil pump 20.

  The front portion of the clutch casing 4a is separated from the inner case portion 4aA by the outer case portion 4aB in the front-rear direction of the work vehicle, and a wind inflow space 25 is formed therebetween, and the outer case portion 4aB flows into the front portion. The air intake 26 communicates with the space 25, and the air intake 26 is connected to an air cleaner for intake (not shown) through a duct. The air intake 26 is connected to the air cleaner during traveling of the work vehicle. The outside air is taken into the wind inflow space 25 and the inside of the clutch 4 can be air-cooled.

The inner and outer case portions 4aA and 4aB are bolted to the body 20a at the end on the engine E side, and the end on the continuously variable transmission mechanism 5 side of the outer case 4aB is bolted to the motor case 8a.
The motor generator 8 is disposed between the clutch 4 and the continuously variable transmission mechanism 5 so as to connect the two, the rotor 9 is fitted and fixed to the rotor shaft portion 6A of the drive shaft 6, and the stator 10 is fixed to the motor case 8a. It is fixed to the inner circumference of the shell by shrinkage.

This motor generator 8 uses a synchronous motor (PMSM) in which a permanent magnet is fixed to a rotor 9, for example, a permanent magnet embedded type concentrated winding synchronous motor (IPM motor), and energizes a stator 10 with concentrated winding of coils. Thus, the rotor 9 in which the permanent magnet is embedded is driven to function as a motor.
The motor generator 8 generates electric power from the stator 10 when the rotor 9 is driven when the engine E rotates at a high speed or when the rotor 9 is driven by power from the continuously variable transmission mechanism 5 during braking or the like. It functions as a generator to extract and can extract electric power and regenerative energy.

In FIG. 4, the rotor 9 of the motor generator 8 is formed, for example, by forming an opening at a circumferential interval on the outer periphery of a rotor core in which a plurality of thin silicon steel plates are laminated, and embedding a permanent magnet 9a in the opening. And the arcuate bulging portion 9b is formed on the outer side of the arrangement position of the permanent magnet 9a, and the arcuate recess 9c that connects the arching bulging portion 9b between the arrangement positions of the permanent magnet 9a is formed. Face to face with a slight gap.

The rotor 9 has a plurality of cooling air insertion holes 15 formed in the rotor core, and allows the wind from the wind inflow space 25 of the clutch casing 4a to flow in the axial direction. The gap between the rotor 9 and the stator 10 is also a cooling air insertion hole 15.
The stator 10 is formed by winding a stator winding 10b directly on a stator core, in which a plurality of thin electrode steel plates 10a are laminated, with a predetermined number of turns to form a concentrated winding, and has a cylindrical shape. In the stator 10, a gap is formed between the stator windings 10b, and the gap serves as a cooling air insertion hole 15 that allows air from the wind inflow space 25 of the clutch casing 4a to flow in the axial direction.

The motor generator 8 has a large number of fins 8b formed on the outer peripheral surface of the motor case 8a, and can be air-cooled from the outside by the wind during traveling of the work vehicle.
Therefore, the motor generator 8 is externally air-cooled via the fins 8 b and is internally air-cooled by the wind from the wind inlet space 25 that flows through the cooling air insertion hole 15 of the rotor 9 and the cooling air insertion hole 15 of the stator 10.

The belt type continuously variable transmission mechanism 5 includes a drive shaft 6 and a driven shaft 33 that are parallel to each other, a drive pulley as a drive member 7 on the drive shaft 6 and a driven pulley 34 on the driven shaft 33, and between the pulleys 7 and 34. And an endless belt 35 wound around and a speed change case 19 surrounding them.
The drive shaft 6 has an end shaft 36 fitted and fixed to the end opposite to the rotor shaft portion 6A, and this end shaft 36 is supported by a support member 37 fixed to the motor case 8a and the transmission case 19 via a bearing 38. Has been.

The drive pulley 7 on the drive shaft 6 is slidable in the axial direction on the end shaft 36 side, and is immovable in the axial direction on the motor generator 8 side.
The driven shaft 33 is formed integrally with or separately from the input shaft 39 of the transmission M, and is connected to the driven shaft 33. The driven pulley 34 on the driven shaft 33 is slidable in the axial direction on the shaft tip side, and the transmission M side is in the axial direction. It is immobile.

  The speed change case 19 has a base case 19A and an outer case 19B that are matched to the shape. The input side of the base case 19A is fixed to the motor case 8a together with the support member 37, and the output side is connected to the transmission case Ma of the transmission M. The outer case 19 </ b> B covers the support member 37 on the input side and the driven pulley 34 on the output side.

The cooling air that has passed through the cooling air insertion hole 15 of the motor generator 8 enters the transmission case 19 and cools the internal components of the belt-type continuously variable transmission mechanism 5.
The rear portion of the base case 19A (or the outer case 19B) has a discharge portion 42 that communicates the inside and the outside, and is configured to discharge the cooling air that has cooled the belt-type continuously variable transmission mechanism 5 to the outside.

A passage extending from the wind inlet 26 of the clutch casing 4a to the wind inlet space 25, the cooling air insertion hole 15 of the motor generator 8, the space in the speed change case 19, and the discharge portion 42 passes through the motor generator 8 from the clutch casing 4a. A cooling air passage 14 is formed that allows the cooling air to flow through and into the transmission mechanism 5.
The engine E and the motor generator 8 are connected to the control means 11, and start and rotation of the engine E, motor drive and generator regeneration operation of the motor generator 8 and the like are controlled.

Based on FIGS. 1-4 and FIG. 5, the control operation | movement by the control means 11 when the hybrid system 1 is mounted in a working vehicle and drive | operated is demonstrated. In FIG. 5, the lower right three curves indicate power, and the upper right three curves indicate torque.
When the engine E is operated alone (indicated by a two-dot chain line A1 in FIG. 5), the rotation of the crankshaft 3 does not bring the centrifugal clutch 4 into the engaged state in an idling state of less than 2000 revolutions when the engine E is started. The belt type continuously variable transmission mechanism 5 is stopped, and the work vehicle is maintained in a stopped state.

  When the rotation of the engine E is increased to approximately 2000 rotations, the centrifugal clutch 4 starts to be engaged, and as the rotation increases, clutch slip decreases, and the torque increases rapidly until approximately 3000 rotations (for example, 2940 rotations) ( The centrifugal clutch 4 is coupled at approximately 3000 revolutions at a maximum torque of 26 Nm) and supplies engine power (indicated by a two-dot chain line A2 in FIG. 5) to the belt type continuously variable transmission mechanism 5.

When the vehicle speed is accelerated to about 10 km / h (maximum torque: 26 Nm), the speed is subsequently changed by the continuously variable transmission mechanism 5 to reach 40 km / h.
When the engine E is operated independently, the motor generator 8 can perform the generator function without performing the motor function. For example, when the engine E is rotated at a medium or high speed of about 2000 revolutions or more, the centrifugal clutch 4 is engaged and the rotor 9 is rotated, so that electric power can be recovered from the stator 10, and the work vehicle can travel at a low speed and generate electricity. Can be done at the same time.

When hybrid operation of the engine E and the motor generator 8 is performed, the motor output of the motor generator 8 can be changed from a torque of about 15 Nm during rated operation to a maximum torque of about 30 Nm.
When rated operation is performed (indicated by a solid line B1 in FIG. 5), the motor generator 8 drives the drive shaft 6 of the continuously variable transmission mechanism 5 regardless of whether the centrifugal clutch 4 is turned on or off even when the rotor 9 has a rotational speed of 0 to 2000. Even if the rotation speed of the rotor 9 is 2000 rotations (the rotation speed of the output member 4B of the centrifugal clutch 4 is also the same), 3 to 4 kW of motor power is generated.

The motor drive of the motor generator 8 reinforces the rotation of the engine E. When the engine single torque is added to the torque of the motor generator 8, hybrid power that is 30 to 80% higher than the engine power of the single operation (solid line in FIG. 5). B2) can be supplied to the continuously variable transmission mechanism 5.
In the case of maximum operation (indicated by a dotted line C1 in FIG. 5), the motor generator 8 can accelerate from a vehicle speed of 0 km / h to 30 Nm, which exceeds the engine single torque, and even if the rotational speed of the rotor 9 is 2000 revolutions, 6-8 Nm is generated and the rotation of the engine E is strongly reinforced (hybrid function). With this hybrid function, the maximum hybrid power (indicated by the dotted line C2 in FIG. 5) about twice as large as the engine power during the single operation can be supplied to the continuously variable transmission mechanism 5 and the vehicle speed can be accelerated rapidly.

When the motor generator 8 is operated independently only by the motor function, that is, the motor generator 8 can be used even when the engine E is stopped or idling, and can supply the drive shaft 6 from the rated torque of 15 Nm to the maximum torque of 30 Nm, and the motor power 3 to 8 kW can be generated and the work vehicle can be driven, and the continuously variable transmission mechanism 5 is also shifted.
When only the motor function of the motor generator 8 is driven, the input member 4A is not driven even if the output member 4B of the clutch 4 is driven. Therefore, the crankshaft 3 does not rotate and the motor power is wasted in the engine E. There is no.

When the work vehicle is decelerated or braked, the rotational force from the continuously variable transmission mechanism 5 drives the rotor 9, and the motor generator 8 enters a generator function state, that is, a braking energy regeneration state. To be recovered.
When a one-way clutch is used as the clutch 4, a clutch capable of connecting / disconnecting power such as a friction clutch is provided in the transmission M. During the rotation of the engine E, the rotor 9 and the drive shaft 6 are driven to transmit power to the belt type continuously variable transmission mechanism 5. At this time, when the motor generator 8 functions as a motor, hybrid power is obtained. Further, when the motor generator 8 functions as a generator, electric power can be obtained.

When the rotational speed of the rotor 9 is higher than that of the crankshaft 3 during deceleration or braking, the motor generator 8 can recover energy, and when the rotational speed of the rotor 9 decreases, rotational resistance is applied to the crankshaft 3 via the one-way clutch. give. At this time, idling of the engine E may be stopped.
When the motor generator 8 functions as a motor without starting the engine E, the work machine can be started and run at a low speed without driving the crankshaft 3 by the one-way clutch.

  As described above, the hybrid system 1 controls the engine E and the motor generator 8 by the control means 11, thereby causing the motor generator 8 to drive the motor of the rotor 9 when the engine E is stopped, at a low speed or at a high speed. The motor function is demonstrated, and it becomes an engine substitute drive source and an engine auxiliary drive source. When the engine E rotates at a medium to high speed, the motor generator 8 exerts a generator function for driving the rotor 9 with the power from the engine E. When the rotational speed of the engine E is reduced, such as deceleration or braking, the motor generator 8 is driven by the generator 9 to drive the rotor 9 with the power from the continuously variable transmission mechanism 5 to perform the generator function. Can be a generator, regenerative brake.

In the present invention, the shape of each member and the positional relationship between the front, back, left, and right in the above embodiment are best configured as shown in FIGS. However, it is not limited to the said embodiment, A member, a structure can be variously deformed, and a combination can also be changed.
For example, instead of the belt type continuously variable transmission mechanism 5, a planetary gear type continuously variable transmission mechanism or other continuously variable transmission mechanism may be used.

DESCRIPTION OF SYMBOLS 1 Hybrid system 3 Crankshaft 4 Clutch 4A Input member 4B Output member 4a Clutch casing 5 Belt type continuously variable transmission mechanism 6 Drive shaft 6A Rotor shaft 7 Drive member (drive pulley)
DESCRIPTION OF SYMBOLS 8 Motor generator 8a Motor case 8b Fin 9 Rotor 10 Stator 11 Control means 14 Cooling air path 15 Cooling air insertion hole 19 Shift case 25 Wind inflow space 26 Wind intake E Engine M Transmission

Claims (6)

An oil pump (20) capable of supporting a crankshaft (3) protruding from the engine (E) is provided, and a one-way automatic transmission clutch (4) is connected to the oil pump (20), and the oil pump The crankshaft (30) extending from the clutch (4) to the clutch (4) is connected to the input member (4A) of the clutch (4), and the output member (4B) of the clutch (4) is connected to the continuously variable transmission mechanism. The motor generator is connected to the drive shaft (6) of (5) and mounted on the drive shaft (6) between the drive member (7) of the continuously variable transmission mechanism (5) and the output member (4B) of the clutch (4). A hybrid system characterized by connecting the rotor (9) of (8). The output member (4B) of the clutch (4) and the drive shaft (6) of the continuously variable transmission mechanism (5) are integrally connected concentrically, and the rotor (9) is fitted and fixed to the drive shaft (6). The motor case (8a ) of the motor generator (8) is fixed to the clutch casing (4a) of the clutch (4) and the transmission case (19) of the continuously variable transmission mechanism (5). Item 2. The hybrid system according to Item 1.   The hybrid system according to claim 1 or 2, wherein the continuously variable transmission mechanism (5) is a belt-type continuously variable transmission mechanism, and the clutch (4) is a centrifugal clutch or a one-way clutch. When the engine (E) is stopped, at a rotational speed at which the power transmission through the clutch (4) is interrupted, at a low rotational speed at which the engine (E) rotates or at a rotational speed at which the power is transmitted through the clutch (4). The control means (11) for driving the rotor (9) with respect to the motor generator (8) during high speed rotation of the engine (E) is provided. The hybrid system according to item.   The control means (11) for driving the rotor (9) with the power from the engine (E) when the engine (E) rotates at high speed is provided. The hybrid system of any one of -4. Control means (11) for driving the rotor (9) to the generator with power from the continuously variable transmission mechanism (5) when the rotational speed of the engine (E) is reduced is provided. The hybrid system according to any one of claims 1 to 5.

Images