JP2012193630A - Power unit of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change characteristics of a prime mover largely, in a power unit of a motorcycle.SOLUTION: In the power unit of the motorcycle, a rotational inertial-weight changing device 20 of the prime mover is disposed. The inertial weight is changed, thereby providing various ride comfort for the motorcycle.

Description

  The present invention relates to a power unit for a motorcycle.

  2. Description of the Related Art A power unit for a motorcycle is known that includes a crank load applying mechanism that applies a load that serves as rotational resistance of the crankshaft to the crankshaft (see, for example, Patent Document 1). In the crank load imparting mechanism of Patent Document 1, the friction member mounted on the crankshaft is pressed against the pressing member by an actuator to generate friction, and the engine characteristic is changed by increasing the apparent rotational inertia weight. The operability of the engine throttle during cornering has been improved.

JP 2008-231990 A

By the way, in motorcycles, the characteristics (engine characteristics) of the prime mover, including the way around the prime mover (engine), is a major factor that determines the character of the motorcycle. It is possible to grant a special character. However, in the above-described conventional motorcycle power unit, the rotation of the crankshaft is prevented by friction. Therefore, when the characteristics of the prime mover are significantly changed, the friction becomes large, and it is difficult to greatly change the characteristics of the prime mover. There is a problem. Further, in the conventional power unit, energy is excessively consumed due to friction that prevents rotation of the crankshaft, so that the efficiency and fuel consumption of the prime mover are deteriorated.
The present invention has been made in view of the above-described circumstances, and an object thereof is to make it possible to greatly change the characteristics of a prime mover in a power unit of a motorcycle.

In order to achieve the above object, according to the present invention, in a power unit of a motorcycle, a rotational inertia weight changing means (20, 120) of a prime mover is provided so that various riding comforts can be given to the motorcycle by changing the inertia weight. It is characterized by that.
According to this configuration, since the rotational inertia weight changing means of the prime mover is provided in the power unit and the rotational inertia weight of the prime mover is changed, the characteristics of the prime mover can be greatly changed. As a result, various characters can be given to the motorcycle.

In the above configuration, the rotary inertia weight changing means (20) includes at least two weight cylinders (21) installed perpendicularly to the rotation shaft (10) and in the weight cylinder (21). It is good also as a structure which has a weight member (22) movable to the radial direction of the said rotating shaft (10), and a moving means (30) which moves the said weight member (22).
In this case, the rotary inertia weight changing means includes at least two weight cylinders installed perpendicularly to the rotation shaft, a weight member movable in the radial direction of the rotation shaft within the weight cylinder, and a weight member. Therefore, the weight member receives a force that moves the weight member outward in the radial direction due to the rotation of the prime mover, and the weight member moves outward in the weight cylinder. For this reason, the rotary inertia weight changing means capable of moving the weight member to the outside by utilizing the rotation of the prime mover can be realized with a simple structure.

The rotating shaft (10) may be a crankshaft (10), and the weight cylinder (21) may be provided in the crank web (12).
In this case, since the rotating shaft is the crankshaft and the weight cylinder is provided in the crank web, it is not necessary to provide a dedicated part for providing the rotating inertia weight changing means on the crankshaft. Will not be long.

Further, the moving means (30) is provided on the radially outer side of the weight cylinder (21), and a spring (23) that presses the weight member (22) radially inward, and the weight cylinder (21). It is good also as a structure which has a hydraulic control circuit (24) which gives a hydraulic_pressure | hydraulic inside the radial direction.
In this case, since the moving means has a spring that presses the weight member inward in the radial direction and a hydraulic control circuit that applies hydraulic pressure radially inward of the weight cylinder, the weight member is moved into the weight cylinder by the spring and the hydraulic control circuit. It can be moved with. In addition, since the weight member is pressed radially inward by the spring, and the weight member is positioned radially inward when starting the prime mover, the rotational inertia weight of the rotating shaft is reduced, and the prime mover is easy to start. become.

Further, when the rotational speed of the power unit is from non-rotation to less than idle rotation, the weight member (22) is positioned on the innermost side in the radial direction, and when the power unit is less than a predetermined middle rotation, the weight member (22) is The weight member (22) may be positioned at the innermost side in the radial direction when the power unit is positioned more than the predetermined middle rotation.
In this case, when the number of rotations of the power unit is from no rotation to less than idle rotation, the weight member is positioned on the innermost side in the radial direction, so that the rotational inertia weight of the rotation shaft is reduced, and the prime mover can be easily started. Further, when the power unit is less than the predetermined middle rotation, the weight member is positioned on the outermost side in the radial direction, so that the rotation inertia weight of the rotation shaft is increased and the rotation of the prime mover during the middle rotation is stabilized. Further, when the power unit is more than the predetermined middle rotation, the weight member is positioned at the innermost side in the radial direction, so that the rotational inertia weight of the rotating shaft is reduced. The response of the prime mover is improved.

Moreover, it is good also as a structure which provided the select switch (31) which enables a passenger | crew to determine the position of the radial direction of the said weight member (22).
In this case, since a select switch is provided that allows the occupant to determine the position of the weight member in the radial direction, the characteristics of the prime mover can be freely selected by changing the rotational inertia weight according to the occupant's intention.

The rotating inertia weight changing means (120) is movable in a radial direction of the rotating shaft in a weight cylinder (21) installed perpendicular to the rotating shaft (10) and the weight cylinder (21). A weight member (22); and a moving means (130) for moving the weight member (22). The weight member (22) divides the weight cylinder (21) into two chambers in a liquid-tight manner, and The switching chamber (25, 35) for selectively connecting the two chambers to either a pressure source or an open end, and a control device (28) for controlling the switching valve (25, 35) may be used. good.
In this case, the weight cylinder is liquid-divided into two chambers by the weight member, the switching valve selectively connecting the two chambers to either the pressure source or the open end, and the control device for controlling the switching valve; Since the weight member can be moved in the radial direction of the rotating shaft within the weight cylinder by controlling the switching valve, the characteristics of the prime mover can be greatly changed by changing the rotational inertia weight.

In the power unit of the motorcycle according to the present invention, the rotational inertia weight changing means of the prime mover is provided in the power unit and the rotational inertia weight of the prime mover is changed, so that the characteristics of the prime mover can be greatly changed. As a result, various characters can be given to the motorcycle.
Further, since the weight member receives the force that moves the outer side in the radial direction due to the increase in the rotation of the prime mover, and the weight member moves outward in the weight cylinder, the weight member is moved outward by using the rotation of the prime mover. It is possible to realize a rotary inertia weight changing means capable of achieving a simple structure.

Further, since the weight cylinder is provided in the crank web, it is not necessary to provide a dedicated part for providing the rotary inertia weight changing means on the crankshaft, and the axial length of the crankshaft is not increased.
Further, the weight member can be moved in the weight cylinder by the spring and the hydraulic control circuit. In addition, since the weight member is pressed radially inward by the spring, and the weight member is positioned radially inward when starting the prime mover, the rotational inertia weight of the rotating shaft is reduced, and the prime mover is easy to start. become.

  Further, when the number of rotations of the power unit is from no rotation to less than idle rotation, the weight member is positioned on the innermost side in the radial direction, so that the rotational inertia weight of the rotating shaft is reduced, and the prime mover can be easily started. Further, when the power unit is less than the predetermined middle rotation, the weight member is positioned on the outermost side in the radial direction, so that the rotation inertia weight of the rotation shaft is increased and the rotation of the prime mover during the middle rotation is stabilized. Further, when the power unit is more than the predetermined middle rotation, the weight member is positioned at the innermost side in the radial direction, so that the rotational inertia weight of the rotating shaft is reduced. The response of the prime mover is improved.

In addition, since the select switch that allows the occupant to determine the radial position of the weight member is provided, the characteristics of the prime mover can be freely selected by changing the rotational inertia weight according to the occupant's intention.
Further, the weight cylinder is divided into two chambers in a liquid-tight manner by the weight member, a switching valve for selectively connecting the two chambers to either the pressure source or the open end, and a control device for controlling the switching valve. Since the weight member can be moved in the radial direction of the rotating shaft within the weight cylinder by controlling the switching valve, the characteristics of the prime mover can be greatly changed by changing the rotational inertia weight.

1 is a cross-sectional view of a crankshaft of a power unit of a motorcycle according to an embodiment of the present invention. It is a schematic diagram which shows a rotation inertia weight change means. It is sectional drawing of the crankshaft in the state in which the hydraulic pressure was supplied to the weight cylinder. It is sectional drawing of the crankshaft which concerns on 2nd Embodiment. It is a schematic diagram which shows a rotation inertia weight change means.

Hereinafter, a power unit of a motorcycle according to an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a cross-sectional view of a crankshaft of a power unit of a motorcycle according to an embodiment of the present invention.
A motorcycle (not shown) has a power unit (not shown) as a power source for driving a rear wheel (not shown). The power unit is configured to generate an engine (not shown) as a prime mover and rotation output from the engine. A transmission (not shown) that shifts and outputs to the rear wheel side is integrally provided in a crankcase (not shown).

A crankshaft 10 (rotary shaft) that converts a reciprocating motion of a piston (not shown) due to fuel combustion into a rotational motion and outputs it is supported on the crankcase of the engine.
FIG. 1 is a cross-sectional view of the crankshaft 10 as viewed from the axial direction. The crankshaft 10 is orthogonal to the axial direction of the crank journal 11 and an axial crank journal 11 that is rotatably supported by the crankcase. The disc-shaped crank web 12 provided in such a manner and the crank pins 13 connecting the pair of crank webs 12 arranged in the axial direction are provided.
The crank journal 11 is provided at the center of each crank web 12 and extends outward in the axial direction of the crankshaft 10. The crank pin 13 is press-fitted into each crank web 12, and one end of a connecting rod (not shown) is connected to the crank pin 13, and the piston is connected to the other end of the connecting rod.

  The crankshaft 10 includes rotational inertia weight changing means 20 that can change the rotational inertia weight (moment of inertia) of the crankshaft 10.

FIG. 2 is a schematic diagram showing the rotary inertia weight changing means 20.
As shown in FIGS. 1 and 2, the rotary inertia weight changing means 20 includes a weight cylinder 21 formed in the crank web 12 and installed perpendicular to the axial direction of the crankshaft 10, and a crank in the weight cylinder 21. The weight member 22 is movable in the radial direction of the shaft 10, and the moving means 30 is configured to move the weight member 22 within the weight cylinder 21.
The moving means 30 is provided at an outer end 21A on the radially outer side of the weight cylinder 21, and a spring 23 that presses the weight member 22 radially inward, and a hydraulic pressure that applies hydraulic pressure to the inner end 21B on the radially inner side of the weight cylinder 21. A control circuit 24 and an inner switching valve 25 that switches the hydraulic pressure of the hydraulic control circuit 24 are provided.

The weight cylinders 21 are provided as a pair symmetrically opposed with respect to the radial center O of the crank web 12, and the axis C <b> 1 of the pair of weight cylinders 21 is a straight line C <b> 2 passing through the center of the crank pin 13 and the center O. It arrange | positions so that it may cross substantially orthogonally. That is, each weight cylinder 21 is disposed at a position rotated by approximately 90 ° from the crankpin 13 to both sides in the circumferential direction. For this reason, the crank cylinder 13 does not interfere with the weight cylinder 21, and the weight cylinder 21 can be easily arranged.
In addition, a pair of weight cylinders 21 is provided symmetrically with respect to the center O, and the weight cylinder 21, the weight member 22, and the spring 23 are disposed at positions separated from the center O by substantially the same distance. Therefore, even if these members are arranged, the crank web 12 is not decentered, and the rotation balance of the crankshaft 10 can be kept good.

The weight member 22 is formed in a cylindrical shape that can slide in the weight cylinder 21, and a spring accommodation hole 22 </ b> A in which the spring 23 is accommodated is formed at the end on the outer end 21 </ b> A side.
The spring 23 is a coil spring. One end of the spring 23 abuts on the outer end 21 </ b> A and the other end is accommodated in the spring accommodating hole 22 </ b> A, and the weight member 22 is urged toward the inner end 21 </ b> B of the weight cylinder 21. When the engine is stopped when the crankshaft 10 is not rotated, the weight member 22 is in a position where it abuts against the inner end 21 </ b> B by being pressed by the spring 23.

  The hydraulic control circuit 24 includes an in-shaft oil passage 11 </ b> A formed in the crank journal 11, and an in-web oil passage 12 </ b> A that connects the in-shaft oil passage 11 </ b> A and the inner end 21 </ b> B of the weight cylinder 21. The in-shaft oil passage 11A is connected to the inner switching valve 25, and the hydraulic pressure from the inner switching valve 25 is supplied to the weight cylinder 21 through the in-shaft oil passage 11A and the web inner oil passage 12A.

  The inner switching valve 25 has a supply-side oil passage 26 connected to a hydraulic pressure source and an open-side oil passage 27 connected to an open end for releasing the hydraulic pressure, and the hydraulic control circuit 24 is supplied to the supply side by switching the valves. It selectively communicates with either the oil passage 26 or the open side oil passage 27. That is, the inner switching valve 25 selectively connects the weight cylinder 21 to either the pressure source or the open end. When the inner switching valve 25 is switched to the supply side oil passage 26, the hydraulic pressure is supplied to the weight cylinder 21, and when the inner switching valve 25 is switched to the opening side oil passage 27, the control oil in the weight cylinder 21 is released. It is pulled out to the end, and the hydraulic pressure is not supplied to the weight cylinder 21.

The inner switching valve 25 is connected to an ECU 28 (control device) that controls each part including the engine of the motorcycle, and the ECU 28 controls switching of the inner switching valve 25.
The ECU 28 is connected to a rotational speed sensor 29 that detects the rotational speed of the engine and a select switch 31 that can be operated by a rider of the motorcycle. The select switch 31 is a switch that allows the occupant to arbitrarily switch the inner switching valve 25, and is installed on a handle (not shown) of the motorcycle. This handle is provided with a throttle (not shown) through which the occupant operates the engine speed.

FIG. 3 is a cross-sectional view of the crankshaft 10 in a state where hydraulic pressure is supplied to the weight cylinder 21.
When the inner switching valve 25 is switched to the supply side oil passage 26 side by the instruction of the ECU 28 and the hydraulic pressure is supplied to the inner end 21B of the weight cylinder 21, the weight member 22 is moved by the hydraulic pressure against the spring 23, It is located on the outermost side in contact with the outer end 21A side. As described above, the weight member 22 moves outward in the radial direction of the crankshaft 10, thereby increasing the actual rotational inertia weight of the crankshaft 10. Here, the state where the weight member 22 contacts the outer end 21A is referred to as a rotational inertia weight increase state. Here, the pair of weight members 22 are moved so as to be always located at symmetrical positions with respect to the center O.
Since the radial position of the weight member 22 affects the rotational inertia weight in a square, the rotational inertia weight of the crankshaft 10 can be greatly increased by moving the weight member 22 outward in the radial direction. it can.
The spring 23 compressed by the hydraulic pressure is accommodated in the spring accommodation hole 22A.

  When the inner switching valve 25 is switched to the open side oil passage 27 side according to an instruction from the ECU 28, the hydraulic pressure is not supplied to the weight cylinder 21, and the weight member 22 is moved from the state shown in FIG. 21 is moved to the innermost side in contact with the inner end 21B of the head 21 and returns to the state of FIG. As a result, the rotational inertia weight of the crankshaft 10 is also reduced and returned to the original rotational inertia weight. Here, the state in which the weight member 22 contacts the inner end 21B is referred to as a rotational inertia weight standard state.

  Based on the engine speed detected by the speed sensor 29, the ECU 28 switches the inner switching valve 25 to change the rotational inertia weight of the crankshaft 10, and based on the operation of the select switch 31 by the occupant. And a manual mode for changing the rotational inertia weight of the crankshaft 10. Switching between the normal mode and the manual mode is performed by operating the select switch 31.

In the normal mode, the ECU 28 switches the inner switching valve 25 to the open-side oil passage 27 side when the detected value of the rotation speed sensor 29 is less than the idle rotation speed, and the weight member 22 as shown in FIG. By positioning the crankshaft 10 at the inner end 21B, the crankshaft 10 is brought into a standard state of rotational inertia weight.
As described above, when the engine is not rotating, the crankshaft 10 is in the standard state of rotational inertia weight, and the rotational inertia weight is small. Therefore, the crankshaft 10 can be easily rotated, and the startability of the engine is improved. . For this reason, the capacity | capacitance of the starter motor (not shown) which rotates the crankshaft 10 at the time of starting can be made small, and size reduction and weight reduction of an engine can be achieved. In addition, since startability is improved, fuel efficiency is also improved. Here, the idle rotation speed is 1300 rpm as an example.

In the normal mode, the ECU 28 switches the inner switching valve 25 to the supply-side oil passage 26 side when the value detected by the rotational speed sensor 29 is equal to or higher than the idle rotational speed and less than the predetermined intermediate rotational speed, and the weight member 22 is changed to FIG. As shown in FIG. 4, the crankshaft 10 is placed in the rotational inertia weight increasing state by being positioned at the outer end 21A. Thus, the crankshaft 10 is in a state where the rotational inertia weight is increased and the rotational inertia weight is large in the middle and low rotation range of the engine, so that the rotation of the engine in the middle and low rotation range can be stabilized. As a result, the engine stall resistance can be improved, and the direction of rotation of the engine changes from that in the standard rotational inertia weight state, so that the occupant feels the character of the motorcycle different from that in the standard rotational inertia weight state. be able to. Specifically, a so-called medium and low rotation type engine characteristic is obtained in which the rotation is stable in the middle and low speed range of the engine, and the passenger can feel a space in the rotation of the engine.
Further, since the switching to the rotational inertia weight increase state is performed while the engine is rotating, when the weight member 22 is moved against the spring 23, the centrifugal force of the weight member 22 is resisted against the spring 23. The weight member 22 can be moved to the outer end 21A with a small hydraulic pressure. Here, the predetermined medium rotation is, for example, 3000 rpm.

  In the normal mode, the ECU 28 switches the inner switching valve 25 to the open-side oil passage 27 side when the detected value of the rotation speed sensor 29 is equal to or greater than the predetermined medium rotation, and the weight member 22 is moved to the inner side as shown in FIG. By positioning at the end 21B, the crankshaft 10 is brought into the rotational inertial weight standard state. As described above, the crankshaft 10 is in the rotational inertia weight standard state and the rotational inertia weight is small in the high rotation range above the predetermined middle rotation of the engine. Response can be improved. In addition, since the rotational inertia weight is small, it is possible to improve the fuel efficiency and to obtain the characteristics of a so-called high rotation type engine that can obtain high output at high rotation.

In the manual mode, when the occupant selects the rotation inertia weight standard state, the ECU 28 switches the inner switching valve 25 to the open side oil passage 27 side, and puts the crankshaft 10 into the rotation inertia weight standard state. In this case, the engine has the characteristics of a high-speed engine in the entire engine speed range.
Further, in the manual mode, when the occupant selects the rotational inertia weight increase state, the ECU 28 switches the inner switching valve 25 to the supply side oil passage 26 side, and puts the crankshaft 10 into the rotational inertia weight increase state. In this case, the engine has the characteristics of a medium / low speed engine in the entire engine speed range.

  As described above, according to the first embodiment to which the present invention is applied, the engine characteristic (the characteristic of the prime mover) is provided in order to change the rotation inertia weight by providing the engine with the rotation inertia weight changing means 20 of the engine. It can be changed greatly. As a result, various characters can be given to the motorcycle. As an example, when the rotational inertia weight is increased, the engine characteristic becomes a medium and low rotation type, and a so-called cruiser type vehicle character can be imparted to the motorcycle. Further, if the rotational inertia weight is kept small, the engine characteristics of the high rotation type can be obtained, and a so-called sports-type vehicle character can be imparted to the motorcycle. For this reason, various characters can be given to one motorcycle, and various riding comforts can be given to passengers. In addition, the apparent rotational inertia weight is not increased by friction, but the actual rotational inertia weight is changed, so that there is no adverse effect on engine efficiency and fuel consumption.

  The rotary inertia weight changing means 20 includes two weight cylinders 21 installed perpendicularly to the crankshaft 10 and a weight member 22 movable in the radial direction of the crankshaft 10 within the weight cylinder 21. And the moving means 30 for moving the weight member 22, the weight member 22 receives a force for moving the weight member 22 outward in the radial direction due to an increase in the rotation of the engine, and the weight member 22 moves outward in the weight cylinder 21. . For this reason, the rotary inertia weight changing means 20 capable of moving the weight member 22 to the outside by utilizing the rotation of the engine can be realized with a simple structure.

Further, since the rotary inertia weight changing means 20 is provided on the crankshaft 10 and the weight cylinder 21 is provided in the crank web 12, a dedicated component for providing the rotary inertia weight changing means 20 is provided on the crankshaft 10. There is no need, and the axial length of the crankshaft 10 does not become long.
Further, since the moving means 30 includes a spring 23 that presses the weight member 22 in the radially inward direction and a hydraulic pressure control circuit 24 that applies hydraulic pressure to the weight cylinder 21 in the radial direction, the spring 23 and the hydraulic control circuit 24 The weight member 22 can be moved in the weight cylinder 21. Further, since the weight member 22 is pressed radially inward by the spring 23 and the weight member 22 is positioned radially inward when starting the engine, the rotational inertia weight of the crankshaft 10 is reduced, and the engine Is easy to start.

In addition, when the rotational speed of the power unit is from non-rotation to less than idle rotation, the weight member 22 is positioned at the innermost inner end 21B in the radial direction, so the rotational inertia weight of the crankshaft 10 is reduced and the engine can be started easily. Become. Further, when the power unit is less than the predetermined middle rotation, the weight member 22 is positioned at the outermost outer end 21A in the radial direction, so that the rotational inertia weight of the crankshaft 10 is increased, and the engine rotation during the middle rotation is stable. To do. Further, when the power unit is more than the predetermined middle rotation, the weight member 22 is positioned at the innermost inner end 21B in the radial direction. The engine response to the throttle operation is improved.
In addition, since the select switch 31 that allows the occupant to determine the radial position of the weight member 22 is provided, the engine characteristic can be freely selected by changing the rotational inertia weight of the crankshaft 10 according to the occupant's intention.

In addition, the said 1st Embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the first embodiment, it has been described that the rotary inertia weight changing means 20 is provided in the engine as the prime mover of the power unit of the motorcycle. However, the present invention is not limited to this, for example, the electric motor The motor provided as the motor for the two-wheeled vehicle may be provided with a rotary inertia weight changing means for changing the rotary inertia weight of the motor. In this case, rotational inertia weight changing means may be provided on the rotating shaft of the motor.
In the first embodiment, the rotary inertia weight changing means 20 has been described as being provided on the crankshaft 10. However, the present invention is not limited to this, and for example, a member that rotates integrally with the crankshaft 10 on the crankshaft 10. And a rotary inertia weight changing means may be provided on this member.
In the first embodiment, the two weight cylinders 21 are described as being installed perpendicularly to the axial direction of the crankshaft 10, but the present invention is not limited to this. It is sufficient that at least two weight cylinders 21 are arranged, and a plurality of sets of a pair of weight cylinders facing each other perpendicularly to the axial direction of the crankshaft 10 may be provided. That is, four may be provided.

[Second Embodiment]
Hereinafter, a second embodiment to which the present invention is applied will be described with reference to FIGS. 4 and 5. In the second embodiment, parts that are configured in the same manner as in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
In the first embodiment, the weight member 22 is described as being pressed radially inward by the spring 23. However, in the second embodiment, the weight member 22 is pressed radially inward by hydraulic pressure. This is different from the first embodiment.

FIG. 4 is a cross-sectional view of the crankshaft 100 according to the second embodiment. FIG. 5 is a schematic diagram showing the rotary inertia weight changing means 120.
As shown in FIGS. 4 and 5, a crankshaft 100 (rotary shaft) of a motorcycle engine includes a crank journal 11, a disc-shaped crank web 112, and a crankpin 13.
The rotary inertia weight changing means 120 capable of changing the rotary inertia weight of the crankshaft 100 includes a weight cylinder 21 formed in the crank web 112 and installed perpendicular to the axial direction of the crankshaft 100, a weight member 22, And a moving means 130 for moving the weight member 22 in the weight cylinder 21.

The moving means 130 includes a hydraulic control circuit 24, an inner switching valve 25, a hydraulic control circuit 34 that applies hydraulic pressure to the outer end 21 </ b> A on the radially outer side of the weight cylinder 21, and an outer switching valve 35 that switches the hydraulic pressure of the hydraulic control circuit 34. And have.
The hydraulic control circuit 34 is provided in a system different from the in-web oil passage 12 </ b> B communicating with the outer end 21 </ b> A through the outer side in the radial direction in the crank web 112 than the outer end 21 </ b> A, And an in-shaft oil passage 11B. The in-shaft oil passage 11B is connected to the outer switching valve 35, and the hydraulic pressure from the outer switching valve 35 is supplied to the weight cylinder 21 through the in-shaft oil passage 11B and the web inner oil passage 12B.

  The weight cylinder 21 is liquid-divided into two chambers by a weight member 22, and includes an inner hydraulic chamber 41 having an inner end 21B and an outer hydraulic chamber 42 having an outer end 21A.

The outer switching valve 35 includes a supply-side oil passage 36 connected to a hydraulic pressure source and an open-side oil passage 37 connected to an open end for releasing the hydraulic pressure, and the hydraulic control circuit 34 is supplied to the supply side by switching the valves. It selectively communicates with either the oil passage 36 or the open side oil passage 37. That is, the outer switching valve 35 selectively connects the outer hydraulic chamber 42 of the weight cylinder 21 to either the pressure source or the open end. When the outer switching valve 35 is switched to the supply side oil passage 36, the hydraulic pressure is supplied to the outer hydraulic chamber 42 of the weight cylinder 21, and when the outer switching valve 35 is switched to the opening side oil passage 37, The control oil is drawn to the open end, and no hydraulic pressure is supplied to the outer hydraulic chamber 42 of the weight cylinder 21. Switching of the outer switching valve 35 is controlled by the ECU 28.
In the inner hydraulic chamber 41, when the inner switching valve 25 is switched to the supply side oil passage 26, the hydraulic pressure is supplied to the inner hydraulic chamber 41, and when the inner switching valve 25 is switched to the open side oil passage 27, the inner hydraulic pressure is increased. The hydraulic pressure in the chamber 41 is released.

The ECU 28 switches the inner switching valve 25 and the outer switching valve 35 to move the weight cylinder 21 in the radial direction of the crankshaft 100 by hydraulic pressure, thereby changing the rotational inertia weight.
Similar to the first embodiment, the ECU 28 changes the rotational inertia weight of the crankshaft 100 based on the rotational speed of the engine detected by the rotational speed sensor 29, so that the rotational inertia weight standard state and the rotational inertia weight are changed. Achieve increased state.
When obtaining the rotational inertia weight standard state, the ECU 28 supplies the hydraulic pressure to the outer hydraulic chamber 42 and releases the hydraulic pressure of the inner hydraulic chamber 41 to bring the weight member 22 into contact with the inner end 21B as shown in FIG. Position it inside.
When the rotational inertia weight increase state is obtained, the ECU 28 supplies the oil pressure to the inner hydraulic chamber 41 and releases the hydraulic pressure of the outer hydraulic chamber 42 so that the weight member 22 is positioned on the outermost side in contact with the outer end 21A.

  According to the second embodiment, the weight cylinder 21 is divided into two chambers, the inner hydraulic chamber 41 and the outer hydraulic chamber 42, by the weight member 22, and the inner hydraulic chamber 41 and the outer hydraulic chamber 42 are respectively divided. An inner switching valve 25 and an outer switching valve 35 that are selectively connected to either the pressure source or the open end, and an ECU 28 that controls the inner switching valve 25 and the outer switching valve 35, and the inner switching valve 25 and the outer switching valve. By controlling the valve 35, the weight member 22 can be moved in the radial direction of the crankshaft 100 in the weight cylinder 21, so that the engine characteristic can be greatly changed by changing the rotational inertia weight of the crankshaft 100. .

In addition, the said 2nd Embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the second embodiment described above, the ECU 28 has been described as changing the rotational inertia weight of the crankshaft 100 to realize the rotational inertia weight standard state and the rotational inertia weight increase state, but the present invention is not limited to this. Not what you want. For example, the ECU 28 adjusts the hydraulic pressure supplied to the inner hydraulic chamber 41 and the outer hydraulic chamber 42 so that the rotational inertia weight can be changed steplessly between the rotational inertia weight standard state and the rotational inertia weight increase state. May be.

10,100 Crankshaft (Rotating shaft)
12, 112 Crank web 20, 120 Rotational inertia weight changing means 21 Weight cylinder 22 Weight member 23 Spring 24 Hydraulic control circuit 25 Inner switching valve (switching valve)
28 ECU (control device)
30, 130 Moving means 31 Select switch 34 Hydraulic control circuit 35 Outer switching valve (switching valve)

Claims (7)

In the power unit of a motorcycle,
A power unit for a motorcycle, characterized in that a rotational inertia weight changing means (20, 120) of a prime mover is provided so that various riding comforts can be given to the motorcycle by changing the inertia weight.   The rotary inertia weight changing means (20) includes at least two weight cylinders (21) installed perpendicularly to the rotation shaft (10), and the rotation shaft (10) in the weight cylinder (21). The power unit of a motorcycle according to claim 1, further comprising a weight member (22) movable in a radial direction) and a moving means (30) for moving the weight member (22).   The power unit for a motorcycle according to claim 2, wherein the rotating shaft (10) is a crankshaft (10), and the weight cylinder (21) is provided in a crank web (12).   The moving means (30) is provided on the radially outer side of the weight cylinder (21), and a spring (23) that presses the weight member (22) radially inward, and a radius of the weight cylinder (21) The motorcycle power unit according to claim 2 or 3, further comprising a hydraulic control circuit (24) for applying hydraulic pressure inward in the direction.   When the rotation speed of the power unit is from non-rotation to less than idle rotation, the weight member (22) is positioned on the innermost side in the radial direction, and when the power unit is less than a predetermined middle rotation, the weight member (22) is The weight member (22) is positioned at the innermost side in the radial direction when the power unit is not less than the predetermined middle rotation. Motorcycle power unit.   The motorcycle power unit according to any one of claims 2 to 5, further comprising a select switch (31) that allows a rider to determine a radial position of the weight member (22).   The rotary inertia weight changing means (120) includes a weight cylinder (21) installed perpendicular to the rotary shaft (10) and a weight member movable in the radial direction of the rotary shaft within the weight cylinder (21). (22) and a moving means (130) for moving the weight member (22). The weight member (22) divides the weight cylinder (21) into two chambers in a liquid-tight manner, and the 2 And a switching valve (25, 35) for selectively connecting the chamber to either the pressure source or the open end, and a control device (28) for controlling the switching valve (25, 35). The power unit of the motorcycle according to claim 1.

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